Next Article in Journal
Feasibility of Ti-6Al-4V Alloys with Nanoporous and Nanotubular Surfaces for the Treatment of Femoral Defects
Previous Article in Journal
Endothelial Glycocalyx in Kidney Transplantation: Molecular Mechanisms, Biomarkers, and Therapeutic Opportunities
Previous Article in Special Issue
Extracellular Molecular Repertoire of Xerotolerant Actinobacteria Сolonizing Serpentinite Rocks
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
IJMS
Volume 27
Issue 10
10.3390/ijms27104336
ijms-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Biochemical Screening of the New Strain Dolichospermum solitarium (Cyanobacteria) for Phytoremediation and Biotechnology

by
Irina Maltseva
1,
Aleksandr Yakoviichuk
1,2,
Svetlana Maltseva
2,
Maxim Kulikovskiy
2 and
Yevhen Maltsev
2,*
1
Faculty of Natural Sciences, Melitopol State University, Melitopol 272312, Russia
2
K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, Moscow 127276, Russia
*
Author to whom correspondence should be addressed.
Int. J. Mol. Sci. 2026, 27(10), 4336; https://doi.org/10.3390/ijms27104336
Submission received: 8 April 2026 / Revised: 6 May 2026 / Accepted: 7 May 2026 / Published: 13 May 2026
(This article belongs to the Special Issue Molecular Biology on Environmental Microorganisms)
Browse Figures
Versions Notes

Abstract

This work described a novel freshwater strain of Cyanobacteria, Dolichospermum solitarium MAC–C17 from the Zaporozhye region in the south of European Russia and characterised its growth and biochemical parameters. The strain demonstrated high biomass, lipid, and protein productivity, comparable to the best-known data for high-productivity cyanobacteria. The highest protein content (383.76 mg g−1 dry weight) was in the exponential growth phase. In contrast, the highest content of lipids, vitamin E (α-tocopherol) and vitamin A (retinol) was in the stationary phase (150.05 mg g−1, 45.58 µg g−1 and 31.61 µg g−1). The productivity of Dolichospermum solitarium MAC–C17 was 19.26 mg L−1 d−1 for lipids, 42.54 mg L−1 d−1 for protein, 4.06 µg L−1 d−1 for retinol, and 5.85 µg L−1 d−1 for α-tocopherol. A distinctive feature of the new strain was its high chlorophyll a content (4.87–6.12 mg g−1). The antioxidant defence system of Dolichospermum solitarium differed between the exponential and stationary growth phases. During the exponential growth phase, strain MAC–C17 exhibited high catalase activity. In contrast, the stationary phase was characterised by a distinct shift in its antioxidant profile, marked by a substantial increase in superoxide dismutase and glutathione peroxidase activities, a significant rise in retinol and α-tocopherol levels. These findings suggest that strain Dolichospermum solitarium MAC–C17 possessed considerable biotechnological potential. It demonstrated strong potential as a producer of high-value commercial compounds, a promising candidate for developing antioxidant formulations, and a valuable asset for applications that boost agricultural yields and advance phytoremediation technologies.

1. Introduction

Cyanobacteria are the most ancient group of photosynthetic organisms, playing a crucial role in oxygenating the atmosphere and shaping early biogeochemical cycles [1]. Among Cyanobacteria, some species combine the ability to photosynthesise with the capacity to fix atmospheric nitrogen. Thus, they play a vital role not only in the Earth’s carbon cycle but also in its nitrogen cycle [2]. Cyanobacteria have a long history of adaptation to diverse environments. Currently, they live in a wide variety of habitats: freshwater and saltwater reservoirs, hot springs, on the surface and in deep soil horizons, on tree bark, rock, and ice surfaces [3,4]. Cyanobacteria can survive at high and low temperatures, in direct sunlight, and in deep soil layers, endure periodic desiccation, and withstand high doses of radiation [5,6,7,8]. Cyanobacteria are producers of organic matter and play a significant role in sustaining food webs in modern ecosystems. Nitrogen-fixing species serve as a source of biologically available nitrogen for the growth of other organisms in nitrogen-poor ecosystems [9,10].
The unique ecological, physiological, and biochemical characteristics of Cyanobacteria have generated significant interest in studying and utilising these organisms in practice. Earlier, Maltsev et al. [8] noted that cyanobacteria improve soil structure and fertility and initiate primary soil formation processes in various industrial landfills. They survive on substrates containing many heavy metals and other toxic compounds, and many researchers have noted their use in phytoremediation technologies [8,9,11]. There is known positive experience in using Cyanobacteria to restore soil fertility and enhance agricultural productivity [9,12], and in technologies for wastewater treatment from various pollutants [13]. As a source of lipids, proteins, polyunsaturated fatty acids, carotenoids (Car), vitamins, enzymes, and other valuable compounds, Cyanobacteria are in demand in pharmacology, the food industry, and biodiesel production [9,14,15,16,17]. It is important to note that in eutrophic water bodies, Cyanobacteria can proliferate massively, causing so-called ‘algal blooms’, which have negative ecological consequences, degrade water quality, and pose risks to the functioning of other aquatic organisms [18,19].
Thus, research into the strategies underlying cyanobacteria’s adaptive capabilities is necessary. This would allow us to control their growth, either by limiting it in eutrophic water bodies or by stimulating it for phytoremediation and the production of commercially valuable compounds in biotechnology. It is well known that strong exposure to one or more factors disrupts the redox balance of cells by generating significant amounts of reactive oxygen species (ROS). The antioxidant system protects cells and counteracts the oxidative damage caused by ROS. The antioxidant system functions through low-molecular-weight and high-molecular-weight antioxidants [20]. Low-molecular-weight compounds, such as α-tocopherol, vitamin A, glutathione, etc., reduce the rate of free radical generation and decrease the concentration of oxidative reaction products. High-molecular-weight antioxidants include various enzymes, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) [21,22]. The restoration of cellular redox balance occurs through a coordinated system of interactions between low- and high-molecular-weight antioxidants [23]. Stressful exposure that exceeds the capacity of the cellular antioxidant system can lead to cell death. Therefore, one of the most important problems to be solved is establishing the features of the antioxidant defence system in Cyanobacteria that enable them to maintain viability under various external influences.
Heterocytous species with single trichomes, grouped in the genus Anabaena Bory ex Bornet et Flahault, often live in various aquatic and terrestrial habitats. These species, along with other cyanobacteria, can cause water blooms; some live in soils, hot waters, and saline biotopes and are highly resistant to abiotic stresses [24,25]. From a practical use perspective, Anabaena, as a nitrogen-fixing organism, holds great potential for developing technologies to enrich agricultural fields with nitrogen compounds [12]. Anabaena species are known for their antibacterial activity [26] and ability to synthesise lipids, carotenoids, and other biotechnologically valuable compounds [14,15,16,17]. Researchers have paid considerable attention to studies of growth dynamics, photosynthesis, and the accumulation of biotechnologically valuable compounds in Anabaena biomass, as well as the search for strategies to increase its productivity [24]. However, at present, there is limited information on the features of the antioxidant protection system in cyanobacteria [27,28].
A recent analysis of Anabaena diversity, considering phenotypic and molecular features, confirmed the heterogeneity of this genus [29]. Planktonic species isolated into a separate genus, Dolichospermum (Bornet et Flahault) P.Wacklin, L.Hoffmann et Komárek [29,30]. While exploring the cyanobacterial flora of the Molochnaya River, we isolated a novel cyanobacterial strain with Dolichospermum-like morphology. The ability of most Dolichospermum species to accumulate lipids, proteins, and vitamins has not yet been studied, and research combining assessments of metabolite synthesis and antioxidant system activity is virtually absent for Cyanobacteria in general.
This study focused on the combined analysis of morphological (light microscopy) and molecular (phylogeny of the 16S rRNA gene) data, and on the screening of lipid, protein, α-tocopherol, and vitamin A content, as well as the antioxidant status, of the new strain Dolichospermum solitarium (Klebahn) Wacklin, L.Hoffmann et Komárek.

2. Results

2.1. Strain Description

Dolichospermum solitarium MAC–C17

Morphological description (Figure 1): Trichomes are isopolar, with constrictions at cross-walls, without firm sheaths. Apical cells are morphologically similar to vegetative cells. Vegetative cells are spherical or slightly oval-elongated, blue-green to brown-green, 6.0–8.2 μm in diameter, with gas vesicles. The cell wall is thin. Intercalary heterocytes are brown-green to brownish, solitary or in pairs, spherical, and 6.0–7.5 in diameter. Akinetes are intercalary, large, long-cylindrical, 22.0–29.0 μm long and 11.0–14.0 μm wide, and solitary or successively in rows. The filaments are solitary or in small clusters.
Habitat: The strain MAC–C17 was isolated from a planktonic sample collected in the Molochnaya River located in the Zaporozhye region (N 46°57′05″, E 35°285′20″). The water temperature was 18 °C with a pH of 7.85.
Sequence data: GenBank accession PZ385169 for the 16S rRNA gene partial sequence.
Molecular analysis: The 16S rDNA phylogenetic tree was constructed using 56 nucleotide sequences of closely related cyanobacterial strains from the National Centre for Biotechnology Information (NCBI) and the novel strain’s sequence. Reconstruction of phylogenetic relationships using maximum likelihood (ML, where BS is the bootstrap support) and Bayesian (BI, where PP is the posterior probability) methods showed that all strains classified at the genus level had a clear separation into different clades (Figure 2). MAC–C17 formed a common clade with the strain D. solitarium 82 with BS 70 and PP 1.0. Comparative analysis of partial 16S sequences (869 bp) for the newly identified MAC–C17 vs. the strain D. solitarium 82 revealed several evolutionary events. MAC–C17 sequence differed by two transitions (A→G and G→A) and ‘G’, ‘C’ and ‘T’ deletions.
Strain MAC–C17 was classified as belonging to the species Dolichospermum solitarium, genus Dolichospermum, family Aphanizomenonaceae, order Nostocales and class Cyanophyceae based on morphology and molecular data.

2.2. Growth and Biochemical Characteristics

In this study, the strain D. solitarium MAC–C17 demonstrated a specific growth rate of 0.12 d−1 and a volumetric biomass productivity of 128.43 mg L−1 d−1. The strain reached the stationary phase on the 15th day of cultivation.
The chlorophyll a (Chl a) and carotenoid content differed between the logarithmic and stationary growth phases (Table 1). The stationary phase was characterised by a 20.4% reduction of Chl a content (Figure 3a). The carotenoid content did not significantly increase in the stationary phase compared to the logarithmic phase (Figure 3b). The Chl a Car−1 ratio shifted in the stationary phase towards an increased proportion of carotenoids and a reduced role of Chl a (Figure 3c).
The lipid content in the biomass of D. solitarium MAC–C17 increased sharply in the stationary phase, reaching 150.05 mg g−1 dry weight (DW), which was almost twice as high as in the logarithmic phase (Figure 4a). The protein content did not change significantly during the strain’s growth (Figure 4b).
In the stationary phase, there was an increase in the content of retinol and α-tocopherol relative to the logarithmic phase by 36.5% and 46.7% (Figure 5), respectively.
The productivity of D. solitarium MAC–C17 was 19.26 mg L−1 d−1 for lipids, 42.54 mg L−1 d−1 for protein, 4.06 µg L−1 d−1 for retinol, and 5.85 µg L−1 d−1 for α-tocopherol.

2.3. SDH and Antioxidant Enzyme Activity

Succinate dehydrogenase (SDH) activity decreased by 1.6-fold with the age of the D. solitarium MAC–C17 culture (Figure 6a). This indicated more intensive energy metabolism in the strain’s cells during the logarithmic growth phase than in the stationary phase.
During the growth of D. solitarium MAC–C17, an increase in GPx and SOD activity was observed in the stationary phase compared to the logarithmic phase, by 30.9% and 33.8%, respectively (Figure 6b,c). Conversely, CAT activity decreased by 36.4% in the stationary phase (Figure 6d).

2.4. Intensity of Lipid Peroxidation Processes at Different Growth Phases

The concentration of thiobarbituric-acid-reactive substance (TBARS) decreased with the age of the culture by 1.24-fold before the initiation of lipid peroxidation (LPO) and by 1.14-fold after the initiation of LPO by Fe2+ ions (TBARSin) (Figure 7a,b). The strain had an antioxidant activity coefficient (KAAC) with a lower value in the stationary growth phase (Figure 7c).

3. Discussion

Wacklin et al. [29] proposed the genus Dolichospermum as a new nomenclatural unit for the planktonic species Anabaena, whose morphotype is characterised by gas vesicles. At the same time, the authors themselves noted that the genus Dolichospermum is not monophyletic. New research has confirmed that Anabaena, Dolichospermum, and Aphanizomenon are grouped in phylogenetic analysis to form the ‘clade Anabaena, Dolichospermum, and Aphanizomenon (ADA)’ [31]. Molecular and phenotypic variability within species of this clade remains a topic of ongoing discussion. The taxonomic categorisation of these genera, as well as the alignment of morphological criteria with phylogenetic analysis results, remains ambiguous [19,30,32,33,34].
Analysis of the morphological features of the strain MAC–C17 showed a high similarity to those of the genus Dolichospermum. The common features were filaments straight, solitary, or sometimes in clusters; trichomes with almost spherical cells, intercalary spherical heterocytes, and cylindrical akinetes [35]. At the same time, strain MAC–C17 was characterised by smaller sizes of heterocytes (up to 7.5 μm in diameter compared to 10.0 μm in diagnosis) and length of akinetes (22.0–29.0 μm compared to 28.0–35.0 μm) [36].
Phylogenetic analysis using the ML and BI methods with the 16S rRNA gene showed that strain MAC–C17 was robustly placed within the ADA group and, first of all, to the strain D. solitarium 82 collected in Lake Karpjärvi, Finland [37]. A sister position to D. solitarium strains was shown by the strains 0tu33s15 and 0tu33s2a of Dolichospermum flos-aquae (Bornet et Flahault) P.Wacklin, L.Hoffmann et Komárek with strains Anabaena sp. 0tu37s9 and 0tu39s7 collected in Lake Tuusulanjärvi, Finland [38]. The differences between the MAC–C17 and these strains were a length of akinetes up to 29.0 μm, versus 13.5–22.0 μm in D. flos-aquae 0tu33s15 and 11.6–18.6 in D. flos-aquae 0tu33s2a; large width of trichomes (up to 8.4 and 9.0 μm) in Anabaena sp. 0tu37s9 and 0tu39s7, respectively. Dolichospermum zinserlingii (Kossinskaja) Wacklin, Hoffmann et Komárek and Dolichospermum compactum (Nygaard) P.Wacklin, L.Hoffmann et J.Komárek strains had the closest phylogenetic position to D. solitarium, albeit with low bootstrap support in MP and BI. Morphologically, D. zinserlingii differed from adjacent akinetes to heterocytes [35]. Smaller sizes of vegetative cells, heterocytes and akinetes were distinct from D. compactum from MAC–C17. Generally, the tree topology corresponded well with previously obtained phylograms [29,38]. One of the exceptions was the position of the strain ‘Anabaena solitaria’ BC Ana 0025, which had a sister position to Dolichospermum planctonicum (Brunnthaler) Wacklin, L.Hoffmann et Komárek strains (Figure 2). Such genetic data imply the possible discrepancy between the strain BC Ana 0025 and D. solitarium.
D. solitarium (formerly Anabaena solitaria Klebahn) is a widely distributed nitrogen-fixing cyanobacterial species in various freshwater reservoirs and is frequently reported among species causing water ‘blooms’ [30,39,40].
The pigment system of Cyanobacteria, which provides photosynthesis, contains only one form of chlorophyll, chlorophyll a, along with pigments such as carotenoids and phycobiliproteins [41]. The Chl a content in D. solitarium MAC–C17 was 4.87–6.12 mg g−1 DW. This is higher than in Anabaena sphaerica Bornet et Flahault MBDU 105 (approximately 1.65 mg g−1 DW) [42], Nostoc sp. (approximately 0.73 mg g−1 DW) [43], and in Bracteacoccus minor (Schmidle ex Chodat) Petrová MZ–Ch31 (approximately 2.75 mg g−1 DW of total chlorophylls) [44], but lower than in Chlorococcum infusionum (Schrank) Meneghini TISTR 8461, which contained 8.45 mg g−1 DW of total chlorophylls [45]. In terms of carotenoid content, D. solitarium MAC–C17 surpassed Synechocystis sp. and Anabaena sphaerica MBDU 105, characterised by 4.5–3.8 µg g−1 DW and 0.5 µg g−1 DW of carotenoids, respectively [42,46], but was lower than in some green microalgae, such as Chlorococcum infusionum TISTR 8461 and Bracteacoccus aggregatus Tereg BM5/15, which contained 4.14 mg g−1 DW and 6.3 mg g−1 DW of carotenoids, respectively [45,47]. Such variability in pigment content is associated with both specific strain characteristics and cultivation parameters [41].
The higher Chl a content in the exponential growth phase of D. solitarium MAC–C17 indicates increased metabolic and photosynthetic activity during this phase compared to the stationary phase. Active photosynthesis is associated with the generation of significant amounts of ROS [48] and enhanced LPO. In the exponential growth phase, SDH activity was higher. SDH is not a direct component of the antioxidant system (AOS), but its activity affects the AOS, as ROS are generated at specific SDH sites [49]. SDH is associated with ATP synthesis through the respiratory chain. In the tricarboxylic acid cycle, SDH also catalyses the oxidation of succinate to fumarate, reducing ubiquinone (coenzyme Q10) to ubiquinol. The antioxidant effect of ubiquinol is related to its ability to neutralise free radicals [50]. Thus, SDH activity plays a vital role in maintaining the cellular redox balance.
In the exponential growth phase, the amount of TBARS and TBARSin in D. solitarium MAC–C17 was higher than in the stationary phase. In addition, during the exponential phase, CAT activity was higher, indicating an active conversion of H2O2 into H2O and O2. At the same time, SOD and GPx activities were higher during the stationary growth phase. This likely reflects the specific features of metabolic adaptations and ROS protection mechanisms in this strain. As the culture grows, nutrient depletion creates stressful growth conditions, leading to increased activity of the antioxidant enzymes SOD and GPx. Earlier studies on cyanobacteria and microalgae grown under various abiotic stresses, including nitrogen starvation, have also reported increased activity of antioxidant enzymes [51,52,53]. Modulation of non-enzymatic antioxidants was also observed in the stationary growth phase—the content of retinol and α-tocopherol increased. Low-molecular-weight antioxidants, including vitamins, can help limit the development of lipid peroxidation reactions associated with oxidative stress. Both α-tocopherol (the most bioactive form of vitamin E) and retinol (the most bioactive form of vitamin A) possess high antioxidant potential [54]. The α-tocopherol content in cyanobacteria is generally low. According to Mudimu et al. [55], the maximum amounts of α-tocopherol in the stationary phase were found in Limnospira maxima (Setchell et N.L.Gardner) Nowicka-Krawczyk, Mühlsteinová et Hauer and Limnospira platensis (Gomont) K.R.S.Santos et Hentschke—177.23 and 146.48 µg g−1 DW, respectively—and in Aphanizomenon gracile Lemmermann and Aphanizomenon flos-aquae Ralfs ex Bornet et Flahault—143.17 and 101.39 µg g−1 DW, respectively. Sakamoto et al. [56] reported that the α-tocopherol content in Nostoc commune Vaucher ex Bornet et Flahault biomass did not exceed 7.7–7.8 µg g−1 DW. In this regard, D. solitarium MAC–C17 occupies an intermediate position.
The retinol content in cyanobacterial and microalgal biomass varies widely, ranging from 0.01 to 4.28 mg g−1 DW [57]. The retinol content in D. solitarium MAC–C17 corresponds to the lower range of known values.
Cyanobacteria are known for their ability to accumulate lipids and proteins. From a biotechnological perspective, the most valuable strains are those that combine high lipid and protein content with high biomass productivity. The biomass productivity of Cyanobacteria spans a wide range: 3.7 mg L−1 d−1 and 30.8 mg L−1 d−1 for Leptolyngbya sp. CENA104 and Trichormus sp. CENA77, respectively [58], and 105.58 mg L−1 d−1 and 127.50 mg L−1 d−1 for Oscillatoria sp. PBGA3 and Tolypothrix sp. PBGA1, respectively [59]. The biomass yield of D. solitarium MAC–C17 in this study exceeded these values and is comparable to the biomass productivity of species known for their biotechnological value: 115.00 mg L−1 d−1 for Chlorella sp., 140.00 mg L−1 d−1 for Ettlia oleoabundans (S.Chantanachat et H.C.Bold) J.Komárek [59], 210–240 mg L−1 d−1 for Nannochloropsis sp., and 240–280 mg L−1 d−1 for Chlorella vulgaris Beijerinck [60].
The biomass of D. solitarium MAC–C17 contained up to 150.05 ± 17.4 mg g−1 DW of lipids, with a lipid productivity of 19.26 mg L−1 d−1. This is significantly higher than for Leptolyngbya sp. CENA104 (0.8 mg L−1 d−1) and Trichormus sp. CENA77 (7.3 mg L−1 d−1) [58], and higher than reported for Wollea vaginicola (F.E.Fritsch et Rich) R.N.Singh, which had a lipid productivity of 15.65 mg L−1 d−1 [17]. It is comparable to Trichormus variabilis (Kützing ex Bornet et Flahault) Komárek et Anagnostidis, which had a lipid productivity of 10.48 mg L−1 d−1 with a higher lipid content (18.55%) in the biomass [61]. Anabaena sphaerica MBDU 105 achieved the highest content of 39.21 ± 0.11% DW and lipid productivity of 31.64 ± 0.52 mg L−1 d−1 under mixotrophic cultivation conditions [42]. The lipid productivity of the well-known oleaginous microalgae Ettlia oleoabundans was 34.95 mg L−1 d−1 [59], while it was 42–63 mg L−1 d−1 for Nannochloropsis sp. and 27–67 mg L−1 d−1 for Chlorella vulgaris [60].
D. solitarium MAC–C17 has a high protein content—up to 383.76 mg g−1 DW in the exponential growth phase. The protein content in the culture decreased with age. By the 16th day of growth, the protein content decreased twofold compared to the beginning of the experiment in Anabaena sphaerica MBDU 105 under photoautotrophic cultivation [42]. Singh [6] described the protein content in Anabaena sp. under basal, glucose + nitrate supplemented, and sucrose + nitrate supplemented media on the 16th day of growth as 167.28 mg g−1, which is lower than the value for D. solitarium MAC–C17. Vijay et al. [46] reported a high protein content similar to D. solitarium MAC–C17 in the biomass of Nostoc sp. and Anabaena sp.—up to 300–350 mg g−1 DW. Earlier, El Semary [12] noted that D. solitarium is a promising species for enriching fields with nitrogen-containing compounds.

4. Materials and Methods

4.1. Cyanobacterial Material

The novel strain MAC–C17 was isolated by micropipetting from a freshwater planktonic sample using an inverted Olympus CKX53 microscope (Hachioji, Tokyo, Japan). A sample was collected on 20 September 2024 from the Molochnaya River in the steppe zone of Russia, the Zaporozhye region (N 46°57′05″, E 35°285′20″). A Zeiss Axio Scope A1 microscope (Oberkochen, Germany), equipped with a ×100 oil immersion lens (NA 1.4) and differential interference contrast, was used for light microscopy and photography. Strain was deposited at the Moscow Algoecoengineering Collection MAC (WDCM1344) at K.A. Timiryazev Institute of Plant Physiology RAS.
Observations of the strain lasted from 7 days to 6 months. The strain was cultivated in Z8 medium [62] and in Z8 without nitrogen, since heterocytes can be facultatively absent in several cyanobacterial species in environments with high nitrogen content [35].

4.2. DNA Extraction, PCR Amplification and Sequencing

Total DNA from the studied strain MAC–C17 was extracted using Chelex 100 Chelating Resin of molecular-biology grade (Bio-Rad Laboratories, Hercules, CA, USA). The 16S rDNA with a total length of 866 bp was amplified using the pair of primers 8F [63] and B23SR [64]. Amplifications were carried out using PCR mastermixes (ScreenMix, Evrogen, Moscow, Russia). The amplification conditions were as follows: initial denaturation for 5 min at 95 °C, followed by 35 cycles of 1 min denaturation at 94 °C, 45 s annealing at 58 °C, and 1 min 40 s extension at 72 °C, with a final extension for 10 min at 72 °C.
PCR products were visualised by horizontal electrophoresis in 1.0% agarose gel stained with SYBRTM Safe (Life Technologies, Carlsbad, CA, USA). The products were purified with a mixture of FastAP, 10× FastAP Buffer, Exonuclease I (Thermo Fisher Scientific, Waltham, MA, USA) and water. The sequencing was performed using a Genetic Analyser 3500 instrument (Applied Biosystems, Waltham, MA, USA). The internal primers CYA359F [65] and Primer 8 [66] were used for sequencing the 16S rDNA.
Editing and assembly of the consensus sequences were performed by processing the direct and reverse chromatograms in Ridom TraceEdit ver. 1.1.0 and Mega ver. 7 software [67]. The nucleotide sequences of the 16S rRNA gene were aligned using Mafft ver. 7 software and the G-INS-i model [68]. The assembled nucleotide sequence for strain MAC–C17 was included in the alignments along with corresponding sequences of 56 cyanobacterial strains downloaded from GenBank (taxon names and accession numbers are given in Figure 2). The selection of strains for phylogenetic analysis was carried out based on the phylogenetic reconstructions [29,38] and on the inclusion of new sequences from GenBank. The outgroup for the 16S rRNA gene tree comprised two strains of Raphidiopsis raciborskii (Wołoszyńska) Aguilera et al. (Aphanizomenonaceae, Nostocales) as a well-supported clade closely related to Dolichospermum strains [31,38,69]. The resulting 16S rRNA gene alignment was 869 characters long.
The dataset was analysed using the Bayesian inference method implemented in Beast ver. 1.10.1 software [70] to construct a phylogeny. For the alignment partition, the most appropriate substitution model, shape parameter α, and a proportion of invariable sites (pinvar) were estimated using the Bayesian information criterion (BIC), as implemented in jModelTest ver. 2.1.10 [71]. This BIC-based model selection procedure selected the HKY + I + G model, pinvar = 0.7940, and α = 0.9550. A Yule process tree prior was used as a speciation model. The analysis ran for 7 million generations with chain sampling every 1000 generations. The parameters-estimated convergence, effective sample size (ESS), and burn-in period were checked using Tracer ver. 1.7.1 software [70]. The initial 25% of the trees were removed, and the remaining trees were retained to reconstruct a final phylogeny. The phylogenetic tree and posterior probabilities of branches were obtained from the remaining trees, which had stable estimates of the parameter models for nucleotide substitutions and likelihood. Maximum likelihood analysis was performed using RAxML ver. 7.0.4 software [72]. The GTR + I + G evolutionary model of substitution was used for ML analyses. Nonparametric bootstrap analysis with 1000 replicas was conducted. FigTree ver. 1.4.4 software and Adobe Photoshop CC ver. 19.0 were used for viewing and editing the tree.

4.3. Growth Assessment

The cultivation parameters for the strain were based on recommendations from previous studies on Cyanobacteria [73,74,75]. During the preparatory stage, the strain was cultured in Z8 medium [62] until it reached the exponential growth phase. This culture was then used to initiate the experiment.
The assessment of strain growth and biochemical characteristics was conducted in batch (periodic) culture without any intervention in the medium composition throughout the growth period. The experiment was carried out in 250 mL Erlenmeyer flasks containing 150 mL of Z8 medium. The flasks were placed on an orbital ELMI Sky Line Shaker S-3 L (ELMI Ltd., Riga, Latvia) and cultured under constant orbital shaking at 150 rpm.
The cultures grew under standardised conditions at 24 °C, with a light intensity of 70 μmol photons m−2 s−1, a colour temperature of 4000 K, and a 16:8 h light/dark photoperiod. The light intensity and colour temperature were measured using the Sekonic C-800 spectrometer (Sekonic Corporation, Tokyo, Japan).
During strain growth, biomass increase was monitored based on optical density changes using an IMPLEN Nanophotometer P300 (Implen GmbH, München, Germany) at λ = 720 nm. The specific growth rate (µ) was calculated using Equation (1) [73]:
µ = ln (OD1 − OD0) (t1 − t0)−1
where OD1 and OD0 were the optical density on day 1 (t1) and day 0 (t0), respectively.
Changes in optical density were used to identify the strain’s growth phases. The DW (g) of the biomass per litter was estimated using a gravimetric method [55].
The biomass productivity (BP, g L−1 day−1) was estimated using the following equation, where X (g L−1) is the concentration of the biomass at the end of the cultivation time t and X0 (g L−1) is the concentration of the biomass at the beginning of the cultivation:
BP (g L−1 day−1) = (X2 − X1) (t2 − t1)−1
where X2 was the dry biomass (g L−1) at time t2 (day) and X1 was the dry biomass (g L−1) at time t1 (day) [76].
Lipid productivity (LP), protein productivity (PP), retinol productivity (RP), and α-tocopherol productivity (TP) were calculated by the following formula:
LP (PP; RP, TP) (g L−1 day−1) = BP × L (P; R; T)/100
where BP—biomass productivity (g L−1 day−1), L (P; R; T) was the lipid (protein, retinol, α-tocopherol) content of the biomass per DW (%) [17].

4.4. Biochemical Parameters Measurement

For strain MAC–C17, all biochemical characteristics were determined during the logarithmic and stationary growth phases. All conditions for sample analysis, as well as instrument settings, have been described in detail in our previous reports: chlorophyll a, carotenoids, lipids, protein, vitamin A, vitamin E content, CAT, GPx, SOD, and SDH activity [44,77,78]. Measurement of thiobarbituric-acid-reactive substance content (TBARS), TBA-reactive products during the induction of lipid peroxidation by Fe2+ ions (TBARSin) and antioxidant activity coefficient (KAAC) calculation described in Yakoviichuk et al. [79].

4.5. Data Analysis

All measurements were carried out in 3 repetitions. The graphs showed the average values and standard deviation. Statistical analysis was carried out using XLSTAT 2018 software (New York, NY, USA). Statistics were obtained in Microsoft Excel ver. 1903 software (Microsoft Office, Redmond, WA, USA) using Student’s t-test. Differences with p ≤ 0.05 were considered statistically significant [80]. To generalise and identify patterns in changes in the vitamin content and activity of various enzyme groups in the studied strains, principal component analysis was applied using Statistica ver. 12.0 software. This method simplifies the model system, better describes a complex nonlinear system of relationships, and dynamically evaluates the system’s initial variables [44].

5. Conclusions

This study demonstrates that Dolichospermum solitarium MAC–C17 exhibits high biomass, lipid, and protein productivity, comparable to the best-known data among Cyanobacteria. This makes it an economically viable feedstock for biodiesel production and for improving soil fertility.
The biomass of Dolichospermum solitarium MAC–C17 is rich in chlorophyll a, carotenoids, and vitamins, underscoring its value as a raw material for producing specific high-value by-products. The modulation of enzymatic and non-enzymatic antioxidants in Dolichospermum solitarium MAC–C17 differed between the exponential and stationary growth phases when cultivated in batch mode. High CAT activity during the exponential phase was replaced in the stationary phase by increased SOD and GPx activities, elevated retinol and α-tocopherol contents, and unchanged carotenoid content. Thus, the strain Dolichospermum solitarium MAC–C17 can be a potential producer of highly valuable commercial products. It also holds promise as a prospective subject for the development of antioxidant preparations, solutions aimed at enhancing agricultural productivity, and phytoremediation.
However, the promising results for Dolichospermum solitarium MAC–C17 come with caveats and a need for further investigation. The productivity and biochemical characteristics were obtained from specific laboratory settings with controlled temperature, light, and growth media. Successfully scaling up the process will require more research to adapt the technology for real-world production. An additional series of experiments will also be needed to determine the composition of anthropogenic substrates that will be most suitable for phytoremediation using the strain.

Author Contributions

Conceptualisation, methodology, I.M. and M.K.; investigation, formal analysis, validation, visualisation, supervision, A.Y. and S.M.; writing—original draft preparation, I.M., A.Y. and Y.M.; project administration, funding acquisition, Y.M. All authors have read and agreed to the published version of the manuscript.

Funding

This publication is based on research carried out with financial support from the Russian Science Foundation (project number 23-74-10081); the percentage contribution is 80%. Cyanobacterial strain cultivation was carried out with financial support from the state assignment from the Ministry of Science and Higher Education of the Russian Federation (theme 124052200012-7, No. FFES-2024-0001); the percentage contribution was 20%.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Demoulin, C.F.; Lara, Y.J.; Cornet, L.; François, C.; Baurain, D.; Wilmotte, A.; Javaux, E.J. Cyanobacteria evolution: Insight from the fossil record. Free Radic. Biol. Med. 2019, 140, 206–223. [Google Scholar] [CrossRef] [PubMed]
  2. Issa, A.A.; Abd-Alla, M.H.; Ohyama, T. Nitrogen fixing cyanobacteria: Future prospect. In Advances in Biology and Ecology of Nitrogen Fixation; Ohyama, T., Ed.; IntechOpen: London, UK, 2014; pp. 23–48. [Google Scholar]
  3. Quesada, A.; Vincent, W.F. Cyanobacteria in the Cryosphere: Snow, Ice and Extreme Cold. In Ecology of Cyanobacteria II; Whitton, B., Ed.; Springer: Dordrecht, The Netherlands, 2012. [Google Scholar] [CrossRef]
  4. Whitton, B.A.; Potts, M. Introduction to the cyanobacteria. In Ecology of Cyanobacteria II; Springer: Dordrecht, The Netherlands, 2012; pp. 1–13. [Google Scholar]
  5. Scherbina, V.V.; Maltseva, I.A.; Solonenko, A.N. Peculiarities of postpyrogene development of algae in steppe biocenoses at Askania Nova Biospheric National Park. Contemp. Probl. Ecol. 2014, 7, 187–191. [Google Scholar] [CrossRef]
  6. Singh, H. Desiccation and radiation stress tolerance in cyanobacteria. J. Basic Microbiol. 2018, 58, 813–826. [Google Scholar] [CrossRef]
  7. Foster, L.; Muhamadali, H.; Boothman, C.; Sigee, D.; Pittman, J.K.; Goodacre, R.; Morris, K.; Lloyd, J.R. Radiation Tolerance of Pseudanabaena catenata, a Cyanobacterium Relevant to the First Generation Magnox Storage Pond. Front. Microbiol. 2020, 11, 515. [Google Scholar] [CrossRef]
  8. Maltsev, Y.; Maltseva, S.; Maltseva, I. Diversity of cyanobacteria and algae during primary succession in iron ore tailing dumps. Microb. Ecol. 2022, 83, 408–423. [Google Scholar] [CrossRef]
  9. Singh, J.S.; Kumar, A.; Rai, A.N.; Singh, D.P. Cyanobacteria: A Precious Bio-resource in Agriculture, Ecosystem, and Environmental Sustainability. Front. Microbiol. 2016, 7, 529. [Google Scholar] [CrossRef]
  10. Tao, Y.; Li, Y.; Fu, Y.; She, S.; Wang, X.; Hou, L.; Chen, C.; Chen, L. Differences in carbon and nitrogen cycling strategies and regional variability in biological soil crust types. Int. J. Mol. Sci. 2025, 26, 3989. [Google Scholar] [CrossRef] [PubMed]
  11. Lourembam, J.; Haobam, B.; Singh, K.B.; Verma, S.; Rajan, J.P. The molecular insights of cyanobacterial bioremediations of heavy metals: The current and the future challenges. Front. Microbiol. 2024, 15, 1450992. [Google Scholar] [CrossRef]
  12. El Semary, N.A. Adverse effects of nitrogenous compounds on nitrogen-fixing cyanobacterium Anabaena solitaria Klebahn. Bangladesh J. Bot. 2020, 49, 1095–1101. [Google Scholar] [CrossRef]
  13. Morillas-España, A.; Sánchez-Zurano, A.; Gómez-Serrano, C.; Ciardi, M.; Acién, G.; Clagnan, E.; Adani, F.; Lafarga, T. Potential of the cyanobacteria Anabaena sp. and Dolichospermum sp. for being produced using wastewater or pig slurry: Validation using pilot-scale raceway reactors. Algal Res. 2021, 60, 102517. [Google Scholar] [CrossRef]
  14. Kaur, R.; Rahman, A.; Mishra, M.; Singh, S.K.; Sundaram, S.; Alok, S. Comparative growth analysis of cyanobacteria from diverse habitats with reference to pigments. Int. J. Pharm. Sci. Res. 2020, 11, 2984–2989. [Google Scholar] [CrossRef]
  15. Sarkar, A.; Rajarathinam, R.; Venkateshan, R.B. A comparative assessment of growth, pigment and enhanced lipid production by two toxic freshwater cyanobacteria Anabaena circinalis FSS 124 and Cylindrospermopsis raciborskii FSS 127 under various combinations of nitrogen and phosphorous inputs. Environ. Sci. Pollut. Res. 2021, 28, 15923–15933. [Google Scholar] [CrossRef]
  16. Parthiban, J.; Jambulingam, R. Enhancing the Biodiesel Production Potential of Synechococcus elongatus and Anabaena Cyanobacterial Strain Isolated from Saline Water Using Different Media Composition and Organic Carbon Sources. Sustainability 2023, 15, 870. [Google Scholar] [CrossRef]
  17. Goldoost, H.; Vahabzadeh, F.; Fallah, N. Lipids productivity of cyanobacterium Anabaena vaginicola in an internally illuminated photobioreactor using LED bar lights. Sci. Rep. 2024, 14, 6857. [Google Scholar] [CrossRef]
  18. Chernova, E.; Sidelev, S.; Russkikh, I.; Voyakina, E.; Babanazarova, O.; Romanov, R.; Kotovshchikov, A.; Mazur-Marzec, H. Dolichospermum and Aphanizomenon as neurotoxins producers in some Russian freshwaters. Toxicon 2017, 130, 47–55. [Google Scholar] [CrossRef]
  19. Scoglio, G.D.; Jackson, H.O.; Purton, S. The commercial potential of Aphanizomenon flos-aquae, a nitrogen-fixing edible cyanobacterium. J. Appl. Phycol. 2024, 36, 1593–1617. [Google Scholar] [CrossRef]
  20. Birben, E.; Sahiner, U.M.; Sackesen, C.; Erzurum, S.; Kalayci, O. Oxidative stress and antioxidant defense. World Allergy Organ. J. 2012, 5, 9–19. [Google Scholar] [CrossRef]
  21. Ahmad, P.; Jaleel, C.A.; Salem, M.A.; Nabi, G.; Sharma, S. Roles of enzymatic and nonenzymatic antioxidants in plants during abiotic stress. Crit. Rev. Biotechnol. 2010, 30, 161–175. [Google Scholar] [CrossRef]
  22. Lü, J.M.; Lin, P.H.; Yao, Q.; Chen, C. Chemical and molecular mechanisms of antioxidants: Experimental approaches and model systems. J. Cell. Mol. Med. 2010, 14, 840–860. [Google Scholar] [CrossRef]
  23. Das, P.; Nutan, K.K.; Singla-Pareek, S.L.; Pareek, A. Oxidative environment and redox homeostasis in plants: Dissecting out significant contribution of major cellular organelles. Front. Environ. Sci. 2015, 2, 70. [Google Scholar] [CrossRef]
  24. Singh, H.; Anurag, K.; Apte, S.K. High radiation and desiccation tolerance of nitrogen-fixing cultures of the cyanobacterium Anabaena sp. strain PCC 7120 emanates from genome/proteome repair capabilities. Photosynth. Res. 2013, 118, 71–81. [Google Scholar] [CrossRef]
  25. Yadav, P.; Singh, R.P.; Rana, S.; Joshi, D.; Kumar, D.; Bhardwaj, N.; Gupta, R.K.; Kumar, A. Mechanisms of Stress Tolerance in Cyanobacteria under Extreme Conditions. Stresses 2022, 2, 531–549. [Google Scholar] [CrossRef]
  26. Abdel-Raouf, N.; Ibraheem, I. Antibiotic activity of two Anabaena species against four fish pathogenic Aeromonas species. Afr. J. Biotechnol. 2010, 7, 2644–2648. [Google Scholar]
  27. Kharwar, S.; Bhattacharjee, S.; Mishra, A.K. Deciphering salinity tolerance in the cyanobacterium Anabaena sphaerica: An evaluation of physiological and biochemical adjustments. Acta Physiol. Plant. 2022, 44, 127. [Google Scholar] [CrossRef]
  28. Srivastava, R.; Kanda, T.; Yadav, S.; Singh, N.; Yadav, S.; Prajapati, R.; Kesari, V.; Atri, N. Salinity pretreatment synergies heat shock toxicity in cyanobacterium Anabaena PCC7120. Front. Microbiol. 2023, 14, 1061927. [Google Scholar] [CrossRef]
  29. Wacklin, P.; Hoffmann, L.; Komárek, J. Nomenclatural validation of the genetically revised cyanobacterial genus Dolichospermum (Ralfs ex Bornet et Flahault) comb. nova. Fottea 2009, 9, 59–64. [Google Scholar] [CrossRef]
  30. Li, X.; Dreher, T.W.; Li, R. An overview of diversity, occurrence, genetics and toxin production of bloom-forming Dolichospermum (Anabaena) species. Harmful Algae 2016, 54, 54–68. [Google Scholar] [CrossRef]
  31. Driscoll, C.B.; Meyer, K.A.; Šulčius, S.; Brown, N.M.; Dick, G.J.; Cao, H.; Gasiūnas, G.; Timinskas, A.; Yin, Y.; Landry, Z.C.; et al. A closely-related clade of globally distributed bloom-forming cyanobacteria within the Nostocales. Harmful Algae 2018, 77, 93–107. [Google Scholar] [CrossRef]
  32. Österholm, J.; Popin, R.V.; Fewer, D.P.; Sivonen, K. Phylogenomic analysis of secondary metabolism in the toxic cyanobacterial genera Anabaena, Dolichospermum and Aphanizomenon. Toxins 2020, 12, 248. [Google Scholar] [CrossRef]
  33. Dreher, T.W.; Davis, E.W.; Mueller, R.S. Complete genomes derived by directly sequencing freshwater bloom populations emphasize the significance of the genus level ADA clade within the Nostocales. Harmful Algae 2021, 103, 102005. [Google Scholar] [CrossRef]
  34. Dreher, T.W.; Davis, E.W.; Mueller, R.S.; Otten, T.G. Comparative genomics of the ADA clade within the Nostocales. Harmful Algae 2021, 104, 102037. [Google Scholar] [CrossRef]
  35. Komárek, J. Cyanoprokaryota. III. Heterocystous Genera. In Süßwasserflora von Mitteleuropa; Büdel, B., Gärtner, G., Krienitz, L., Schagerl, M., Eds.; Springer Spektrum: Berlin/Heidelberg, Germany, 2013; Volume 19, 1130p. [Google Scholar]
  36. Klebahn, H. Gasvacuolen, ein Bestandteil der Zellen der wasserblütebildenden Phycochromaceen. Flora 1895, 80, 241–282. [Google Scholar]
  37. Gugger, M.; Lyra, C.; Henriksen, P.; Couté, A.; Humbert, J.-F.; Sivonen, K. Phylogenetic comparison of the cyanobacterial genera Anabaena and Aphanizomenon. Int. J. Syst. Evol. Microbiol. 2002, 52, 1867–1880. [Google Scholar] [CrossRef]
  38. Rajaniemi, P.; Hrouzek, P.; Kaštovská, K.; Willame, R.; Rantala, A.; Hoffmann, L.; Komárek, J.; Sivonen, K. Phylogenetic and morphological evaluation of the genera Anabaena, Aphanizomenon, Trichormus and Nostoc (Nostocales, Cyanobacteria). Int. J. Syst. Evol. Microbiol. 2005, 55, 11–26. [Google Scholar] [CrossRef]
  39. Patova, E.N. Bloom-Forming Cyanoprokaryotes in Kharbeyskie Lakes of Bolshezemelskaya Tundra. J. Sib. Fed. Univ. 2014, 7, 282–290. [Google Scholar] [CrossRef]
  40. Dos Santos Machado, L.; Dörr, F.; Dörr, F.A.; Frascareli, D.; Melo, D.S.; Gontijo, E.S.J.; Friese, K.; Pinto, E.; Rosa, A.H.; Pompêo, M.M.; et al. Permanent occurrence of Raphidiopsis raciborskii and cyanotoxins in a subtropical reservoir polluted by domestic effluents (Itupararanga reservoir, São Paulo, Brazil). Environ. Sci. Pollut. Res. 2022, 29, 18653–18664. [Google Scholar] [CrossRef]
  41. Deepika, C.; Wolf, J.; Roles, J.; Ross, I.; Hankamer, B. Sustainable Production of Pigments from Cyanobacteria. Adv. Biochem. Eng. Biotechnol. 2023, 183, 171–251. [Google Scholar] [CrossRef]
  42. Anahas, A.M.P.; Prasannabalaji, N.; Muralitharan, G. Enhancing biodiesel production in Anabaena sphaerica MBDU 105: Exploring photo-, hetero-, and mixotrophic cultivation for biomass, lipid, and fuel properties. Biomass Conv. Bioref. 2025, 15, 7927–7946. [Google Scholar] [CrossRef]
  43. Dewi, R.N.; Mahreni; Azimatun Nur, M.M.; Siahaan, A.A.; Ardhi, A.C. Enhancing the biomass production of microalgae by mixotrophic cultivation using virgin coconut oil mill effluent. Environ. Eng. Res. 2023, 28, 220059. [Google Scholar] [CrossRef]
  44. Maltseva, I.; Kochubey, A.; Yakoviichuk, A.; Maltseva, S.; Kulikovskiy, M.; Maltsev, Y. A Comparative Study of the Antioxidant Status and Biotechnological Potential of Bracteacoccus minor (Chlorophyceae) Strains. Int. J. Mol. Sci. 2025, 26, 10740. [Google Scholar] [CrossRef] [PubMed]
  45. Babadi, F.E.; Boonnoun, P.; Nootong, K.; Powtongsook, S.; Goto, M.; Shotipruk, A. Identification of carotenoids and chlorophylls from green algae Chlorococcum humicola and extraction by liquefied dimethyl ether. Food Bioprod. Process. 2020, 123, 296–303. [Google Scholar] [CrossRef]
  46. Vijay, A.K.; Prabha, S.; Salim, S.A.M.; Atheesh, O.S.; George, B. Isolation and Screening of Indigenous Microalgal Strains from Diverse Ecological Niches for Lipid and Pigment Production Relevant to Sustainable Biorefinery Applications. Bioenerg. Res. 2025, 18, 70. [Google Scholar] [CrossRef]
  47. Chekanov, K.; Litvinov, D.; Fedorenko, T.; Chivkunova, O.; Lobakova, E. Combined Production of Astaxanthin and β-Carotene in a New Strain of the Microalga Bracteacoccus aggregatus BM5/15 (IPPAS C-2045) Cultivated in Photobioreactor. Biology 2021, 10, 643. [Google Scholar] [CrossRef]
  48. Foyer, C.H.; Hanke, G. ROS production and signalling in chloroplasts: Cornerstones and evolving concepts. Plant J. 2022, 111, 642–661. [Google Scholar] [CrossRef]
  49. Jardim-Messeder, D.; Caverzan, A.; Rauber, R.; de Souza Ferreira, E.; Margis-Pinheiro, M.; Galina, A. Succinate dehydrogenase (mitochondrial complex II) is a source of reactive oxygen species in plants and regulates development and stress responses. New Phytol. 2015, 208, 776–789. [Google Scholar] [CrossRef] [PubMed]
  50. Liu, M.; Lu, S. Plastoquinone and Ubiquinone in Plants: Biosynthesis, Physiological Function and Metabolic Engineering. Front. Plant Sci. 2016, 7, 1898. [Google Scholar] [CrossRef]
  51. Srivastava, A.K.; Bhargava, P.; Rai, L.C. Salinity and copper-induced oxidative damage and changes in the antioxidative defence systems of Anabaena doliolum. World J. Microbiol. Biotechnol. 2005, 21, 1291–1298. [Google Scholar] [CrossRef]
  52. Zhang, Y.M.; Chen, H.; He, C.L.; Wang, Q. Nitrogen starvation induced oxidative stress in an oil-producing green alga Chlorella sorokiniana C3. PLoS ONE 2013, 8, e69225. [Google Scholar] [CrossRef]
  53. Chokshi, K.; Pancha, I.; Ghosh, A.; Mishra, S. Nitrogen starvation-induced cellular crosstalk of ROS-scavenging antioxidants and phytohormone enhanced the biofuel potential of green microalga Acutodesmus dimorphus. Biotechnol. Biofuels 2017, 10, 60. [Google Scholar] [CrossRef]
  54. Vašková, J.; Stupák, M.; Vidová Ugurbaş, M.; Židzik, J.; Mičková, H. Therapeutic Uses of Retinol and Retinoid-Related Antioxidants. Molecules 2025, 30, 2191. [Google Scholar] [CrossRef] [PubMed]
  55. Mudimu, O.; Koopmann, I.K.; Rybalka, N.; Friedl, T.; Schulz, R.; Bilger, W. Screening of microalgae and cyanobacteria strains for α-tocopherol content at different growth phases and the influence of nitrate reduction on α-tocopherol production. J. Appl. Phycol. 2017, 29, 2867–2875. [Google Scholar] [CrossRef]
  56. Sakamoto, T.; Wei, Y.; Yuasa, K.; Nishiyama, Y. Recovery of photosynthesis after long-term storage in the terrestrial cyanobacterium Nostoc commune. J. Gen. Appl. Microbiol. 2022, 68, 169–174. [Google Scholar] [CrossRef]
  57. Del Mondo, A.; Smerilli, A.; Sane, E.; Sansone, C.; Brunet, C. Challenging microalgal vitamins for human health. Microb. Cell Fact. 2020, 19, 201. [Google Scholar] [CrossRef]
  58. Da Rós, P.C.M.; Silva, C.S.P.; Silva-Stenico, M.E.; Fiore, F.; de Castro, H.F. Assessment of chemical and physico-chemical properties of cyanobacterial lipids for biodiesel production. Mar. Drugs 2013, 11, 2365–2381. [Google Scholar] [CrossRef]
  59. Thangavel, K.; Krishnan, P.R.; Nagaiah, S.; Kuppusamy, S.; Chinnasamy, S.; Rajadorai, J.S.; Olaganathan, G.N.; Dananjeyan, B. Growth and metabolic characteristics of oleaginous microalgal isolates from Nilgiri biosphere Reserve of India. BMC Microbiol. 2018, 18, 1. [Google Scholar] [CrossRef]
  60. Griffiths, M.J.; van Hille, R.P.; Harrison, S.T.L. Lipid productivity, settling potential and fatty acid profile of 11 microalgal species grown under nitrogen replete and limited conditions. J. Appl. Phycol. 2012, 24, 989–1001. [Google Scholar] [CrossRef]
  61. El Shafay, S.M.; Gaber, A.; Alsanie, W.F.; Elshobary, M.E. Influence of Nutrient Manipulation on Growth and Biochemical Constituent in Anabaena variabilis and Nostoc muscorum to Enhance Biodiesel Production. Sustainability 2021, 13, 9081. [Google Scholar] [CrossRef]
  62. Kotai, J. Instructions for Preparation of Modified Nutrient Solution Z8 for Algae; Publication B-11/(69); Norwegian Institute for Water Research: Oslo, Norway, 1972; 5p. [Google Scholar]
  63. Lane, D.J. 16S/23S rRNA sequencing. In Nucleic Acid Techniques in Bacterial Systematics; Stackebrandt, E., Goodfellow, M., Eds.; Wiley: Chichester, UK, 1991; pp. 115–175. [Google Scholar]
  64. Lepère, C.; Wilmotte, A.; Meyer, B. Molecular diversity of Microcystis strains (Cyanophyceae, Chroococcales) based on 16S rDNA sequences. Syst. Geogr. Plants 2000, 70, 275–283. [Google Scholar] [CrossRef]
  65. Nübel, U.; Garcia-Pichel, F.; Muyzer, G. PCR primers to amplify 16S rRNA genes from cyanobacteria. Appl. Environ. Microbiol. 1997, 63, 3327–3332. [Google Scholar] [CrossRef] [PubMed]
  66. Flechtner, V.R.; Boyer, S.L.; Johansen, J.R.; DeNoble, M.L. Spirirestis rafaelensis gen. et sp. nov. (Cyanophyceae), a new cyanobacterial genus from arid soils. Nova Hedwig. 2002, 74, 1–24. [Google Scholar] [CrossRef]
  67. Kumar, S.; Stecher, G.; Tamura, K. MEGA7: Molecular evolutionary genetics analysis version 7.0 for bigger datasets. Mol. Biol. Evol. 2016, 33, 1870–1874. [Google Scholar] [CrossRef]
  68. Katoh, K.; Toh, H. Parallelization of the MAFFT multiple sequence alignment program. Bioinformatics 2010, 26, 1899–1900. [Google Scholar] [CrossRef] [PubMed]
  69. Zapomělová, E.; Skácelová, O.; Pumann, P.; Kopp, R.; Janeček, E. Biogeographically interesting planktonic Nostocales (Cyanobacteria) in the Czech Republic and their polyphasic evaluation resulting in taxonomic revisions of Anabaena bergii Ostenfeld 1908 (Chrysosporum gen. nov.) and A. tenericaulis Nygaard 1949 (Dolichospermum tenericaule comb. nova). Hydrobiologia 2012, 698, 353–365. [Google Scholar] [CrossRef]
  70. Drummond, A.J.; Rambaut, A. BEAST: Bayesian evolutionary analysis by sampling trees. BMC Evol. Biol. 2007, 7, 214. [Google Scholar] [CrossRef]
  71. Darriba, D.; Taboada, G.L.; Doallo, R.; Posada, D. jModelTest 2: More models, new heuristics and parallel computing. Nat. Methods 2012, 9, 772. [Google Scholar] [CrossRef]
  72. Stamatakis, A.; Hoover, P.; Rougemont, J. A rapid bootstrap algorithm for the RAxML web servers. Syst. Biol. 2008, 57, 758–771. [Google Scholar] [CrossRef]
  73. Devi, K.M.; Mehta, S.K. Antimicrobial activities of freshwater cyanobacterium, Nostoc sp. from Tamdil Wetland of Mizoram, India: An identification of bioactive compounds by GC-MS. Int. J. Pharm. Sci. Res. 2016, 7, 1179–1191. [Google Scholar]
  74. Guljamow, A.; Kreische, M.; Ishida, K.; Liaimer, A.; Altermark, B.; Bähr, L.; Hertweck, C.; Ehwald, R.; Dittmann, E. High-density cultivation of terrestrial Nostoc strains leads to reprogramming of secondary metabolome. Appl. Environ. Microbiol. 2017, 83, e01510-17. [Google Scholar] [CrossRef] [PubMed]
  75. Mouga, T.; Pereira, J.; Moreira, V.; Afonso, C. Unveiling the cultivation of Nostoc sp. under controlled laboratory conditions. Biology 2024, 13, 306. [Google Scholar] [CrossRef]
  76. Polat, E.; Yuksel, E.; Altınbaş, M. Mutual effect of sodium and magnesium on the cultivation of microalgae Auxenochlorella protothecoides. Biomass Bioenergy 2020, 132, 105441. [Google Scholar] [CrossRef]
  77. Maltseva, I.; Yakoviichuk, A.; Maltseva, S.; Cherkashina, S.; Kulikovskiy, M.; Maltsev, Y. Biochemical and Antioxidant Characteristics of Chlorococcum oleofaciens (Chlorophyceae, Chlorophyta) under Various Cultivation Conditions. Plants 2024, 13, 2413. [Google Scholar] [CrossRef] [PubMed]
  78. Maltseva, I.; Yakoviichuk, A.; Maltseva, S.; Kulikovskiy, M.; Maltsev, Y. Antioxidant Status of Cyanobacteria Strains During Long-Term Cultivation in Nitrogen-Free Media. Int. J. Mol. Sci. 2025, 26, 10891. [Google Scholar] [CrossRef]
  79. Yakoviichuk, A.; Krivova, Z.; Maltseva, S.; Kochubey, A.; Kulikovskiy, M.; Maltsev, Y. Antioxidant Status and Biotechnological Potential of New Vischeria vischeri (Eustigmatophyceae) Soil Strains in Enrichment Cultures. Antioxidants 2023, 12, 654. [Google Scholar] [CrossRef] [PubMed]
  80. Marques de Sá, J.P. Applied Statistics: Using SPSS, Statistica, MATLAB, and R, 2nd ed.; Springer: New York, NY, USA, 2007. [Google Scholar]
Ijms 27 04336 g001
Figure 1. Morphological characteristics of Dolichospermum solitarium MAC–C17. Nomarski interference micrographs, scale bar = 10 μm. Individual filaments with intercalary heterocytes, age 1 week (a). Mature filaments with gas vesicles, age 3 weeks (b).
Figure 1. Morphological characteristics of Dolichospermum solitarium MAC–C17. Nomarski interference micrographs, scale bar = 10 μm. Individual filaments with intercalary heterocytes, age 1 week (a). Mature filaments with gas vesicles, age 3 weeks (b).
Ijms 27 04336 g001
Ijms 27 04336 g002
Figure 2. Phylogenetic position of the new Dolichospermum solitarium strain (indicated in bold) within Anabaena, Dolichospermum, and Aphanizomenon Morren ex Bornet et Flahault genera, based on Bayesian inference for the partial 16S rRNA gene. The total length of the alignment is 869 characters. Values above the horizontal lines are bootstrap support (>50%) from ML analyses; values below the horizontal lines (or to the right of the slash) are Bayesian posterior probabilities (>0.9). Strain numbers (if available) and GenBank accession numbers are indicated for all sequences.
Figure 2. Phylogenetic position of the new Dolichospermum solitarium strain (indicated in bold) within Anabaena, Dolichospermum, and Aphanizomenon Morren ex Bornet et Flahault genera, based on Bayesian inference for the partial 16S rRNA gene. The total length of the alignment is 869 characters. Values above the horizontal lines are bootstrap support (>50%) from ML analyses; values below the horizontal lines (or to the right of the slash) are Bayesian posterior probabilities (>0.9). Strain numbers (if available) and GenBank accession numbers are indicated for all sequences.
Ijms 27 04336 g002
Ijms 27 04336 g003
Figure 3. Chl a (a), carotenoids (b) and Chl a Car−1 ratio (c) in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Figure 3. Chl a (a), carotenoids (b) and Chl a Car−1 ratio (c) in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Ijms 27 04336 g003
Ijms 27 04336 g004
Figure 4. Lipids (a) and protein (b) content in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Figure 4. Lipids (a) and protein (b) content in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Ijms 27 04336 g004
Ijms 27 04336 g005
Figure 5. Retinol (a) and α-tocopherol (b) content in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Figure 5. Retinol (a) and α-tocopherol (b) content in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Ijms 27 04336 g005
Ijms 27 04336 g006
Figure 6. SDH (a), GPx (b), CAT (c) and SOD (d) activity in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Figure 6. SDH (a), GPx (b), CAT (c) and SOD (d) activity in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Ijms 27 04336 g006
Ijms 27 04336 g007
Figure 7. TBARS (a), TBARSin (b) content and KAAC (c) in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Figure 7. TBARS (a), TBARSin (b) content and KAAC (c) in Dolichospermum solitarium MAC–C17 biomass. Colours correspond to the data for orange—logarithmic growth phase; green—stationary growth phase. The difference between logarithmic and stationary growth phases was significant at p ≤ 0.05 (M ± SD, n = 3).
Ijms 27 04336 g007
Table 1. Biochemical and antioxidant characteristics of the strain Dolichospermum solitarium MAC–C17 strain in cultures (M ± SD, n = 3).
Table 1. Biochemical and antioxidant characteristics of the strain Dolichospermum solitarium MAC–C17 strain in cultures (M ± SD, n = 3).
IndicatorLogarithmic Phase, 8th DayStationary Phase, 16th Day
Chl a, mg g−1 DW6.12 ± 0.344.87 ± 0.05
Carotenoids, mg g−1 DW1.33 ± 0.071.43 ± 0.04
Chl a Car−11:0.221:0.29
Lipids, mg g−1 DW85.15 ± 9.21150.05 ± 17.4
Protein, mg g−1 DW383.76 ± 24.62331.22 ± 33.43
Retinol, µg g−1 DW23.15 ± 1.5731.61 ± 2.14
α-tocopherol, µg g−1 DW31.06 ± 1.4845.58 ± 1.97
SDH, µmol mg−1 min−11.15 ± 0.110.71 ± 0.07
GPx, nmol mg−1 min−197.0 ± 2.36127.0 ± 9.18
CAT, pmol mg−1 min−13.63 ± 0.122.31 ± 0.05
SOD, 10 u.unit mg−1 min−12.72 ± 0.783.64 ± 0.54
TBARS, nmol g−1 DW34.52 ± 1.8527.94 ± 0.83
TBARSin, nmol g−1 DW58.44 ± 2.5551.23 ± 2.74
KAAC0.590.55
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Maltseva, I.; Yakoviichuk, A.; Maltseva, S.; Kulikovskiy, M.; Maltsev, Y. Biochemical Screening of the New Strain Dolichospermum solitarium (Cyanobacteria) for Phytoremediation and Biotechnology. Int. J. Mol. Sci. 2026, 27, 4336. https://doi.org/10.3390/ijms27104336

AMA Style

Maltseva I, Yakoviichuk A, Maltseva S, Kulikovskiy M, Maltsev Y. Biochemical Screening of the New Strain Dolichospermum solitarium (Cyanobacteria) for Phytoremediation and Biotechnology. International Journal of Molecular Sciences. 2026; 27(10):4336. https://doi.org/10.3390/ijms27104336

Chicago/Turabian Style

Maltseva, Irina, Aleksandr Yakoviichuk, Svetlana Maltseva, Maxim Kulikovskiy, and Yevhen Maltsev. 2026. "Biochemical Screening of the New Strain Dolichospermum solitarium (Cyanobacteria) for Phytoremediation and Biotechnology" International Journal of Molecular Sciences 27, no. 10: 4336. https://doi.org/10.3390/ijms27104336

APA Style

Maltseva, I., Yakoviichuk, A., Maltseva, S., Kulikovskiy, M., & Maltsev, Y. (2026). Biochemical Screening of the New Strain Dolichospermum solitarium (Cyanobacteria) for Phytoremediation and Biotechnology. International Journal of Molecular Sciences, 27(10), 4336. https://doi.org/10.3390/ijms27104336

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop