Search Results (156)

Salt stress is a major constraint to seed germination and early seedling growth in rice, affecting crop establishment and productivity. To understand the mechanisms underlying salt tolerance, we investigated two rice varieties with contrasting responses as follows: salt-tolerant sea rice 86 (SR86) and salt-sensitive P559. Germination assays under increasing NaCl concentrations (50–300 mM) revealed that 100 mM NaCl induced clear phenotypic divergence. SR86 maintained bud growth and showed enhanced root elongation under moderate salinity, while P559 exhibited significant growth inhibition. Transcriptomic profiling of buds and roots under 100 mM NaCl identified over 3724 differentially expressed genes (DEGs), with SR86 showing greater transcriptional plasticity, particularly in roots. Gene ontology enrichment revealed tissue- and genotype-specific responses. Buds showed enrichment in photosynthesis-related and redox-regulating pathways, while roots emphasized ion transport, hormonal signaling, and oxidative stress regulation. SR86 specifically activated genes related to photosystem function, DNA repair, and transmembrane ion transport, while P559 showed activation of oxidative stress-related and abscisic acid (ABA)-regulated pathways. Hormonal profiling supported transcriptomic findings as follows: both varieties showed increased gibberellin 3 (GA3) and gibberellin 4 (GA4) levels under salt stress. SR86 showed elevated auxin (IAA) and reduced jasmonic acid (JA), whereas P559 maintained stable IAA and JA levels. Ethylene precursor and salicylic acid levels declined in both varieties. ABA levels rose slightly but not significantly. These findings suggest that SR86’s superior salt tolerance results from rapid growth, robust transcriptional reprogramming, and coordinated hormonal responses. This study offers key insights into early-stage salt stress adaptation and identifies molecular targets for improving stress resilience in rice. Full article

Schizochytrium-derived omega-3 polyunsaturated fatty acids (e.g., docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) are proven to be health-beneficial bioactive substances that have been widely applied in the pharmaceutical, nutraceutical, and food industries. In this work, the newly isolated Schizochytrium sp. FJ-1 strain was selected to investigate the effects of salinity on the growth performance, lipid production, DHA yield, and positional distribution of triacylglycerols (TAGs). In addition, Schizochytrium sp. 20888 was used as a control strain. The obtained results showed that Schizochytrium sp. FJ-1 could grow with a low biomass in the absence of sea salt; however, Schizochytrium sp. 20888 did not grow in the medium without sea salt. Moreover, Schizochytrium sp. FJ-1 achieved the highest biomass in 10‰ salinity, whilst Schizochytrium sp. 20888 attained the greatest biomass in 40‰ salinity. In terms of the total lipid content and TAG fraction percentage, Schizochytrium sp. FJ-1 grown in 5–20‰ salinity had high total lipid contents (57.04–60.02%), with TAGs accounting for over 90% of the lipid fraction. The highest DHA contents for total lipids (41.38%) and TAGs (40.18%) were obtained when Schizochytrium sp. FJ-1 was grown under 10‰ salinity conditions. Additionally, under the same culture condition, EPA contents of lipids and TAGs were significantly higher for Schizochytrium sp. FJ-1 compared with Schizochytrium sp. 20888. Furthermore, nuclear magnetic resonance analysis found that the salinity level had a distinct impact on the positional distribution of DHA in TAGs in these two Schizochytrium strains. Schizochytrium sp. FJ-1 grown under 40‰ salinity conditions produced TAGs with the greatest percentage of sn-2 DHA (81.24%). The percentages were higher than those found for the other groups of this microalga and Schizochytrium sp. 20888. Taken together, Schizochytrium sp. FJ-1 could be a potential candidate to produce highly valued DHA lipids or TAG bioproducts by regulating salinity. Full article

Agar can be degraded into agar-oligosaccharides by physical, chemical, and biological methods, but the further industrial application of agar-oligosaccharides has been limited by the environmental pollution of traditional agar-oligosaccharides preparation methods and the lack of novel agarase. In this study, we reported the screening of 12 strains with agar-degrading activity from sea cucumber intestine and mucus using a combination of Gram’s iodine staining and 3,5-dinitrosalicylic acid (DNS) method, during which five fungal strains exhibited high agarase activity. Their production of different agarases and agar-oligosaccharides could be visualized by zymogram assay and thin-layer chromatography. A strain ACD-11-B with the highest agarase activity showed 99.79% similarity to Aspergillus sydowii CBS593.65 for ITS rDNA sequence. Strain ACD-11-B produced five possible agarases with predicted molecular weights of 180, 95, 43, 33, and 20 kDa, approximately. The optimal temperature and pH of the crude enzyme production by strain ACD-11-B were 40 °C and 6.0. The crude enzyme was stable at 30 °C, and Ca²⁺, K⁺, and Na⁺ could increase the activity of the crude enzyme. Its agarases demonstrated remarkable salt tolerance and substrate specificity, with neoagarobiose (NA2) identified as the main degradation product. These results indicate that the fungal strain ACD-11-B can secrete agarases with potential in industrial applications, making it a new producer strain for agarase production. Full article

Proteolytic enzymes, which play a crucial role in peptide bond cleavage, are widely applied in various industries. In this study, protease-producing bacteria were isolated and characterized from marine sediments collected from the Yellow Sea, China. Comprehensive screening and 16S rDNA sequencing identified a promising G4 strain as Bacillus atrophaeus. Following meticulous optimization of fermentation conditions and medium composition via response surface methodology, protease production using strain G4 was significantly enhanced by 64%, achieving a yield of 3258 U/mL. The G4 protease exhibited optimal activity at 50 °C and pH 7.5, demonstrating moderate thermal stability with 52% residual activity after 30-min incubation at 50 °C—characteristics typical of an alkaline protease. Notably, the enzyme retained over 79% activity across a broad pH range (6–11) and exhibited excellent salt tolerance, maintaining over 50% activity in a saturated NaCl solution. Inhibition by phenylmethylsulfonyl fluoride, a serine protease inhibitor, confirmed its classification as a serine protease. The enzyme’s potential in generating bioactive peptides was further demonstrated through hydrolysis of sheep (Ovis aries) placenta, resulting in a hydrolysate with notable antioxidant properties. The hydrolysate exhibited a 64% superoxide anion scavenging activity, surpassing that of reduced glutathione. These findings expand the current understanding of Bacillus atrophaeus G4 proteases and provide a foundation for innovative sheep placenta utilization with potential industrial applications. Full article

Photosynthetic bacteria exhibit significant bioremediation potential and resource recycling characteristics, rendering them valuable candidates for sustainable wastewater treatment applications. Sea cucumber boiling broth (SCBB) contains high concentrations of organic compounds and nutrient salts, whose indiscriminate discharge poses serious environmental risks. This study aimed to evaluate a photosynthetic bacterium capable of effectively treating SCBB, which was isolated from the intertidal sediment samples. The bacterial strain was identified using 16S rDNA sequencing, and optimal growth conditions, including light, pH, and temperature, were determined. Finally, a small-scale trial was conducted in a fed-batch fermenter. The results showed that 16S rDNA analysis placed this strain in the Chromatiaceae family, forming a distinct lineage from the closest related species Marichromatium purpuratum and M. gracile, and was tentatively named Marichromatium sp. DYYC01. The strain exhibited optimal growth under anaerobic conditions at 30 °C, light intensity of 100 μmol photons/m²/s, and pH 7.0. Batch culture experiments demonstrated maximum biomass accumulation (OD₆₆₀ = 0.831) in SCBB medium with an initial COD loading of 3913 mg L⁻¹, concomitant with significant nutrient removal efficiencies: 76.45% COD, 55.82% total nitrogen (TN), and 56.67% total phosphorus (TP). Scaling up to fed-batch fermentation enhanced bioremediation performance, achieving removal rates of 83.13% COD, 72.17% TN, and 73.07% TP with enhanced growth (OD₆₆₀ = 1.2). This study reveals Marichromatium sp. DYYC01’s exceptional halotolerance in high-salinity organic wastewater treatment. The strain’s capacity for simultaneous biomass production and efficient nutrient recovery from hypersaline processing effluent positions it as a promising candidate for developing circular bioeconomy strategies. Full article

Squalene is an important bioactive substance widely used in the food, pharmaceutical, and cosmetic industries. Microbial production of squalene has gained prominence in recent years due to its sustainability, safety, and environmental friendliness. In this study, a mutant strain, Pseudozyma sp. P4-22, with enhanced squalene-producing ability, was obtained through atmospheric and room temperature plasma mutagenesis of the previously screened squalene-producing yeast Pseudozyma sp. SD301. The P4-22 strain demonstrated the ability to produce squalene using various carbon and nitrogen sources. We optimized the culture conditions by employing cost-effective corn steep liquor as the nitrogen source, and the optimal pH and sea salt concentration of the medium were determined to be 5.5 and 5 g/L, respectively. Under optimal cultivation conditions, the biomass and squalene production reached 64.42 g/L and 2.06 g/L, respectively, in a 5 L fed-batch fermentation. This study highlights the potential of Pseudozyma sp. P4-22 as a promising strain for commercial-scale production of squalene. Full article

In order to explore a model for the deterioration rate law and mechanism of concrete performance in salt lake water or sea water, the mixed sand concrete test of different forms of chloride ion erosion under a dry–wet cycle was simulated in the laboratory. The compressive strength and penetration depth were used to characterize the structural degradation degree of mixed sand concrete. The performance degradation of mixed sand concrete was analyzed through field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), thermogravimetry (TG), and nuclear magnetic resonance (NMR) testing. Experimental investigations have revealed that, at an age of 140 days and under alternating wet–dry conditions, liquid chloride ion erosion results in a 17.47% reduction in the compressive strength of blended sand concrete, accompanied by an erosion depth of 28.077 mm. This erosion progresses from the exterior towards the interior of the material. Conversely, gaseous chloride ion erosion exhibits a bidirectional penetration pattern. When subjected to gaseous chloride ion erosion, the compressive strength of blended sand concrete decreases by 31.36%, with an associated erosion depth of 38.008 mm. This exposure subjects the structure to heightened crystalline pressures, leading to severe deterioration of both the micro-porous structure within the concrete and the dense structure of hydration products. Consequently, the overall extent of structural damage is more pronounced, and the rate of degradation progression is accelerated. Under the action of liquid chloride ion erosion, the degradation of mixed sand concrete structure is caused by dry–wet fatigue, crystallization pressure, chloride salt erosion and calcium ion dissolution. Under the action of spray-born chloride erosion, the degradation of the mixed sand concrete structure is caused by dry–wet fatigue, crystallization pressure, chloride salt erosion, and calcium ion dissolution, among which crystallization degradation plays a major role. In line with the engineering standards for the utilization of vast desert resources in Inner Mongolia and the long-term service of concrete in the Hetao Irrigation District, our approach contributes to the achievement of sustainable development. Full article

Natural gas hydrate (NGH) is a clean resource characterized by abundant potential reserves, clean combustion, and high energy density. Although significant progress has been made in the development of NGH resources all around the world, challenges still exist that hinder commercial exploitation, such as a low daily gas production rate and short steady production periods. One significant reason lies in the complex gas–liquid–solid phase transitions occurring within the formation during production, which lead to changes in flow capacity. Understanding the phase change mechanism of NGH reservoirs will help to further reveal the production increase mechanism. To address the phase transitions’ effect on production, this paper establishes a numerical simulation model for the depressurization exploitation of natural gas hydrates in order to investigate phase transition characteristics at the field scale. First, the phase equilibrium calculation method is presented and the phase equilibrium curve is modified by considering the capillary effect, soluble salt, and surface adsorption. Then, the phase transition model is successfully characterized in a simulation and the numerical simulation model is established based on the first test project parameters in the Shenhu area. The production characteristics of different sediment types (montmorillonite, South China Sea sediments, kaolin, and silt) are analyzed under the effects of water content and salinity. It is shown that lower initial water content and higher salinity result in higher gas production. The results provide a better understanding of the effects of phase transition parameters on NGH production at the field scale. Full article

Treatment of extremely saline water such as the brine rejected from reverse osmosis water desalination plants, and produced water from shale oil and non-conventional gas extraction, is considered a global problem. Consequently, in this work, hollow fiber membrane distillation (HFMD) is experimentally evaluated for desalinating extremely saline water of a salinity ranging from 40,000 to 130,000 ppm. For the purpose of comparison, the HFMD is also tested for desalinating brackish (3000–12,000 ppm) and sea (25,000–40,000 ppm) water. Firstly, the HFMD is tested at two values of feed water temperature (65 and 76 °C) and flow rate (600 and 850 L/h). The experimental results showed that the HFMD productivity significantly increases when the temperature of feed water increases. Increasing the feed water flow rate also has a positive effect on the productivity of HFMD. It is also concluded that the productivity of the HFMD is not significantly affected by increasing the salt concentration when brackish and sea water are used. The productivity also slightly decreases with increasing the salt concentration when extremely saline water is used. The decrement in the productivity reaches 27%, when the salt concentration increases from 40,000 to 130,000 ppm. Based on the conducted economic analysis, the HFMD shows a good potential for desalinating extremely saline water especially when the solar collector is used as a heat source. In this case, the cost per liter of freshwater is reduced by 21.7–23.1% when the evacuated tube solar collectors are used compared to the system using electrical heaters. More reduction in the cost per liter of freshwater is expected when a high capacity solar-powered HFMD plant is installed. Full article

This study explores the influence of algal incorporation on the sensory and physicochemical attributes of caseless sausage—ćevap (CSC). Various algae, including Chlorella vulgaris, Himanthalia elongata (sea spaghetti), and Undaria pinnatifida (wakame), were added at different concentrations to standard CSC formulations. Proximate analysis revealed that the addition of algae did not significantly change crude protein and fat content (p > 0.05). Furthermore, sea spaghetti and wakame resulted in lower moisture levels and decreased cooking loss, while all algae varieties raised the salt content (p < 0.05) due to their inherent sodium levels. Texture analysis demonstrated that the inclusion of sea spaghetti and Chlorella led to reductions in hardness and chewiness, while wakame resulted in a firmer texture, highlighting its substantial impact on textural attributes. Color measurements indicated that wakame significantly affected the color profile (p < 0.05), resulting in decreased lightness and increased darkness in the sausage, surpassing the effects of other algae. Sensory evaluations showed that formulations containing wakame received the lowest scores for color, smell, taste and overall acceptability—up to 1.5 points lower compared to the control samples. On the other hand, some formulations with other algae showed promising small deviations from the control. Overall, this research supports the viability of using algae as functional ingredients in meat products, emphasizing the importance of selecting the appropriate type and concentration of algae to optimize both physicochemical parameters and sensory qualities in caseless sausages. Full article

Mangroves are one of the world’s most productive and ecologically important ecosystems, and they are threatened by the widespread invasion of Spartina alterniflora Loisel in China. As few studies have examined the spatial pattern differences of S. alterniflora invasion and the nearby mangroves in different latitudes, we chose the Zhangjiang Estuary and the Dandou Sea, two representative mangrove–salt marsh ecotones in the north and south of the Tropic of Cancer, as the study areas for comparison. The object-based image analysis and visual interpretation methods were combined to construct fine-scale mangrove and S. alterniflora maps using high-resolution satellite imagery from 2005 to 2019. We applied spatial analysis, centroid migration, and landscape indexes to analyze the spatio–temporal distribution changes of mangroves and S. alterniflora in these two ecotones over time. We used the landscape expansion index to investigate the S. alterniflora invasion process and expansion patterns. The annual change rates of mangrove and S. alterniflora areas in the Zhangjiang Estuary showed a continuous growth trend. However, the mangrove areas in the Dandou Sea showed a fluctuating trend of increasing, decreasing, and then increasing again, while S. alterniflora areas kept rising from 2005 to 2019. Spartina alterniflora showed larger annual change rates compared with mangroves, indicating rapid S. alterniflora invasion in the intertidal zones. The opposite centroid migration directions of mangroves and S. alterniflora and the decreasing distances between the mangrove and S. alterniflora centroids indirectly revealed the fierce competition between mangroves and S. alterniflora for habitat resources. Both regions saw a decrease in mangrove patch integrality and connectivity. The integrality of mangrove patches in the Zhangjiang Estuary was always higher than those in the Dandou Sea. We observed the growth stage (2011–2014) and outbreak stage (2014–2019) of S. alterniflora expansion in the Zhangjiang Estuary and the outbreak stage (2005–2009) and plateau stage (2009–2019) of S. alterniflora expansion in the Dandou Sea. The expansion pattern of S. alterniflora varies in time and place. Since the expansion of S. alterniflora in the outbreak stage is rapid, with a large annual change rate, early warning of S. alterniflora invasion is quite important for the efficient and economical removal of the invasive plant. Continuous and accurate monitoring of S. alterniflora is highly necessary and beneficial for the scientific management and sustainable development of coastal wetlands. Full article

To establish and implement effective policies for controlling fine particle matters (PM_2.5), which is associated with high-risk diseases, continuous research on identifying PM_2.5 sources was conducted. This study utilized the positive matrix factorization (PMF) receptor model to estimate the sources and characteristics of PM_2.5 between Baengnyeong Island (BNI) and the Seoul Metropolitan Area (SMA). We conducted PMF modeling and backward trajectory analysis using the data on PM_2.5 and its components collected from 2020 to 2021 at the Air quality Research Centers (ARC). The PMF modeling identified nine pollution sources in both BNI and the SMA, including secondary sulfate, secondary nitrate, vehicles, biomass burning, dust, industry, sea salt particles, coal combustion, and oil combustion. Secondary particulate matter, vehicles, and biomass burning were found to be major contributors to PM_2.5 concentrations in both regions. A backward trajectory analysis indicated that air masses, passing through BNI to the SMA, showed higher concentrations and contributions of ammonium nitrate, vehicles, and biomass burning in the SMA site compared to BNI site. These findings suggest that controlling nitrogen oxides (NOx) and ammonia emissions in the SMA, as well as monitoring the intermediate products that form aerosols, such as HNO₃, are needed. Full article

Sea salt farms are the source of salt, an indispensable essential ingredient in various foods and products. Further, they act as frontlines to protect marine disasters from entering domestic residential areas. However, sea salt farming has decreased in popularity among recent-generation farmers in Samut Songkhram Province, Thailand. This paper presents the development of an affordable virtual learning (AVL) application for Thailand’s sea salt farming. Fitts’ law was applied to optimize user-interactive objects’ size and placement to reduce selection time. The sample consisted of 127 multigenerational users, namely those in Generation X, Generation Y, and Generation Z. This study found that the developed AVL applied Fitts’ law to be used harmoniously with VR economical equipment. A total of 90.55% of multigenerational users were satisfied with the developed AVL. The “Looking” and “Executing by eye focus” activities were enjoyed by 100% of participants. The following activities were “Walking” and “Listening”, with 82.68% and 77.95% enjoying them, respectively. Generation Z users responded more to the “Walking” activity than Generation X and Y users. In addition, the hypothesis testing result of learning outcomes through AVL was consistent among multigenerational users. Therefore, the developed AVL should be used as a medium to conserve sea salt farming in Thailand. Full article

Soil salinity represents a significant factor affecting agricultural productivity and crop quality. The present study was conducted to investigate the effects of soil conditioner (SC) comprising halotolerant microorganisms on the soil fertility, yield, rice quality, and the physicochemical and structural properties of starch in hybrid rice under saline conditions. The experimental treatments were composed of two high-quality hybrid rice varieties, i.e., ‘Y Liangyou 957’ (YLY957) and Jing Liangyou 534 (JLY534), and two soil amendment treatments, i.e., the application of SC at control levels and 2250 kg hm⁻², or ‘CK and SC’, respectively. The crop was subjected to a mixture of fresh and sea water (EC 11 dS/m). The results demonstrated that the application of SC significantly enhanced the rice yield under salt stress conditions owing to an increase in the number of grains per panicle. Furthermore, SC was found to be effective in improving the organic matter and soil nutrient content. Furthermore, the application of SC resulted in an improvement in antioxidant defense, higher leaf SPAD values, and greater crop biomass, as well as the translocation of photo-assimilates at the heading stage. The application of SC not only improved the milling and appearance quality but also enhanced the taste value of rice by increasing the amylose and reducing the protein content. Furthermore, the application of SC also decreased the indentations on the surfaces of starch granules and cracks on the edges of the granules. The rice varieties subjected to SC exhibited excellent pasting properties, characterized by reduced proportions of amylopectin short chains and a lower gelatinization temperature and enthalpy of gelatinization. Overall, these findings serve to reinforce the efficacy of soil conditioner as a valuable tool to improve rice productivity and sustainability with improved rice grain quality under saline conditions. Full article

The increasing utilization of zinc oxide nanoparticles (ZnO-NPs) in many consumer products is of concern due to their eventual release into the natural environment and induction of potentially adverse impacts. The behaviour and environmental impacts of ZnO-NPs could be altered through their interactions with environmentally coexisting substances. This study investigated the changes in the behaviour of ZnO-NPs in the presence of coexisting organic pollutants (such as perfluorooctanoic acid [PFOA]), natural organic substances (i.e., humic acid [HA]), and electrolytes (i.e., NaCl and CaCl₂) in simulated waters. The size, shape, purity, crystallinity, and surface charge of the ZnO-NPs in simulated water after different interaction intervals (such as 1 day, 1 week, 2 weeks, and 3 weeks) at a controlled pH of 7 were examined using various characterization techniques. The results indicated alterations in the size (such as 162.4 nm, 1 day interaction to >10 µm, 3 weeks interaction) and zeta potential (such as −47.2 mV, 1 day interaction to −0.2 mV, 3 weeks interaction) of the ZnO-NPs alone and when PFOA, electrolytes, and HA were present in the suspension. Different influences on the size and surface charge of the nanoparticles were observed for fixed concentrations (5 mM) of the different electrolytes. The presence of HA-dispersed ZnO-NPs affected the zeta potential. Such dispersal effects were also observed in the presence of both PFOA and salts due to their large aliphatic carbon content and complex structure. Cation bridging effects, hydrophobic interactions, hydrogen bonding, electrostatic interactions, and van der Waals forces could be potential interaction forces responsible for the adsorption of PFOA. The presence of organic pollutants (PFOA) and natural organic substances (HA) can transform the surface characteristics and fate of ZnO-NPs in natural and sea waters. Full article