Applied Microbiology

Cocoa fermentation is a critical postharvest process that determines the physicochemical and sensory quality of cocoa beans through complex microbial and biochemical transformations. This study evaluated the effect of selected lactic acid bacteria (LAB), i.e., Weissella confusa and Lactiplantibacillus plantarum, and the fermentation system on the fermentation dynamics and final quality of two cocoa genotypes (i.e., Theobroma cacao L.; Nacional and CCN-51). A completely randomized 2 × 2 × 2 factorial design was applied, considering cocoa genotypes, LAB species, and fermentation system (i.e., laboratory fermentation and cascade-type box fermentation). During fermentation, pH, temperature, and total soluble solids (°Brix) were monitored at 0, 24, 48, and 72 h. In addition, cut test parameters and the physicochemical properties of the final cocoa paste were evaluated. The results showed a progressive decrease in pH (from 3.13 to 4.17), accompanied by a temperature increase up to 46.50 °C and a marked reduction in soluble solids during the final fermentation stages, reflecting intense microbial metabolism and substrate utilization. Treatments inoculated with L. plantarum achieved the highest proportion of well-fermented beans (up to 93.73%), indicating enhanced fermentation performance. Furthermore, the physicochemical properties of the final cocoa paste, including moisture, fat, ash, pH, and °Brix, were significantly influenced by the interaction among cocoa genotype, LAB species, and fermentation system. Overall, controlled fermentation using selected LAB species represents a promising biotechnological strategy for improving cocoa fermentation consistency and enhancing postharvest cocoa quality. Full article

Prebiotic potential refers to the stimulation of beneficial bacteria over pathogenic strains. This preliminary study evaluated the prebiotic potential of five agave-derived carbohydrate preparations using lactic acid bacteria (LAB) and Escherichia coli (pathogenic) strains. The tested substrates included commercial inulin, commercial agave syrup, artisanal maguey syrup, aqueous and cooked agave extract. Six Lactobacillus strains (Lactobacillus acidophilus, Lacticaseibacillus casei, Lactiplantibacillus plantarum ATCC 8014, Limosilactobacillus reuteri NRRL B-14171, Lactiplantibacillus plantarum NRRL B-4496, and Lacticaseibacillus rhamnosus) were evaluated against E. coli ATCC 43888 and E. coli clinical isolates. Carbohydrate characterization included analyses of total and reducing carbohydrates and thin-layer chromatography (TLC) to assess the degree of polymerization (DP). Prebiotic Index (PI) and Prebiotic Activity Score (PAS) were calculated to determine selective growth stimulation at 24 and 48 h. TLC analysis revealed two distinct groups: high-molecular-weight compounds (aqueous agave extract and commercial inulin), and low-molecular-weight compounds (cooked agave extract, commercial agave syrup, and artisanal maguey syrup). L. reuteri NRRL B-14171 exhibited the highest PI (approaching 2.0) with aqueous agave extract at 24 h. L. rhamnosus demonstrated superior PAS values across all prebiotic sources, while commercial inulin and artisanal maguey syrup showed the most favorable PAS values against clinical E. coli isolates, indicating preferential in vitro growth of LAB over the pathogen. These findings represent preliminary indications of selective carbohydrate utilization by LAB strains under controlled in vitro conditions. Further studies, incorporating digestion resistance, fermentation by complex microbiota, metabolite production, and host-related effects are required before confirming prebiotic functionality. Full article

Lactic acid bacteria (LAB) from traditional foods are a useful source of natural biopreservatives. This study isolated and characterized indigenous LAB from goat meat produced in the argan grove ecosystem of the Souss-Massa region, Morocco, to identify strains that could improve food safety and shelf life. LAB were isolated under anaerobic conditions and screened by Gram staining, catalase test, growth profiling, and biochemical assays. Proteolytic, gelatinase, and hemolytic activity were assessed, together with antimicrobial activity against foodborne pathogens by agar well diffusion. The most promising strains were identified by 16S rRNA gene sequencing. The selected isolates belonged to Latilactobacillus and Enterococcus. Several isolates strongly inhibited Salmonella enterica, Listeria monocytogenes and Staphylococcus aureus, and none were hemolytic or gelatinase-positive. The sustained inhibition even after neutralization of pH suggested that the antimicrobial effects might be mediated by bacteriocin-like compounds or other non-acidic metabolites. In the strains tested, L. sakei MG4013 gave the best results because of its wide range of antimicrobial activity and absence of hemolytic, gelatinase, proteolytic and lipolytic activities. Goat meat from the Souss-Massa region therefore harbours LAB with biopreservative potential, with potential for use as natural preservatives in traditional meat products or as starter cultures in fermented foods. However, before being used as natural preservatives or starter cultures, they need to be further validated in food matrices. Full article

This research focused on the plant growth-promoting properties of endophytic bacteria isolated from Morisonia scabrida, a tree adapted to heat stress. Sixteen bacterial strains were isolated; among them, S1R21 tolerated 50 °C; S1H21 inhibited the growth of Fusarium sp. FH at 25 and 30 °C; and S1R16 inhibited Alternaria sp. ATCC20084 and F. oxysporum CTLM12 at 25 and 30 °C. Regarding enzymatic activities, S1R21 exhibited amylase activity at 30 °C; S1T20 showed proteinase activity at 37 °C; S1T11 showed pectinase activity at 37 °C; S1R16 and S1R9 demonstrated lipase activity; and S1R20 showed CMCase activity at 30 °C. S1T1 solubilized tricalcium phosphate at 25 and 30 °C; S1H5 produced siderophores at 30 °C; and S1T11 produced IAA and fixed nitrogen at 30 and 37 °C. With respect to germination percentage of corn and alfalfa, the highest values were achieved with strain S1R21 at 30 and 37 °C. Seven strains were selected and identified by 16S rDNA analysis as Bacillus albus S1H21, Bacillus cereus S1R21, Lysinibacillus fusiformis S1R9, Enterobacter sp. (S1H5 and S1R8), Klebsiella sp. S1R16 and Stutzerimonas stutzeri S1T11. Most of these strains increased growth parameters of Zea mays and Medicago sativa, with Stutzerimonas stutzeri S1T11 standing out regarding high aerial and root length, as well as fresh and dry weight. This research study is one of the few studies on endophytic bacteria associated with the Morisonia scabrida tree. It demonstrates that its bacterial diversity could contribute to various biological roles, such as that of plant growth promoter under heat stress. Full article

High fructose intake rapidly induces protein glycation, oxidative stress, inflammation, and disturbances in the cultivable fraction of gut bacteria, contributing to early metabolic impairment. This study examined whether selected plant-derived bioactives and a prebiotic–probiotic formulation could mitigate fructose-induced biochemical and microbial alterations. Male Wistar rats were fed fructose for 45 days, and advanced glycation end product (AGE)-associated fluorescence, oxidative stress markers, and lipid peroxidation were measured to assess metabolic changes. Culture-dependent enumeration of intestinal and fecal bacteria was performed to evaluate shifts in cultivable aerobic and facultative bacterial counts, while limonene, eugenol, and emodin were tested for antibacterial activity against aerobic and facultative bacterial isolates obtained from fructose-fed rats during our previous study. The prebiotic–probiotic formulation was assessed alone and in combination with these bioactives. Fructose feeding increased protein glycation, oxidative stress, lipid peroxidation, and reduced counts of cultivable gut bacteria. Treatment with the bioactives and the formulation lowered glycation-related fluorescence, reduced oxidative stress, and decreased lipid peroxidation. The bioactives exhibited antioxidant and antiglycation activity and inhibited growth of selected cultivable bacterial isolates, including Corynebacterium stationis. While emodin contributed primarily through its known α-glucosidase inhibitory and antiglycation properties rather than antibacterial activity. Combined treatment partially restored cultivable bacterial counts and improved metabolic parameters. Overall, the interventions attenuated fructose-induced biochemical disturbances and modulated the cultivable gut bacterial counts, suggesting a complementary approach to managing early metabolic changes in rats associated with high fructose intake. Full article

Endophytic bacteria from medicinal plants are increasingly recognised as sources of antimicrobial metabolites. However, the endophytic bacterial community of Mitrephora heyneana remains poorly explored. In the present study, endophytic bacteria were isolated from the leaves of M. heyneana, collected from the Western Ghats of Tamil Nadu, India. Among seven isolates, the plant endophyte strain from leaf 6th strain (PEL6) was identified as Paenibacillus lactis through 16S rRNA gene sequencing. The ethyl acetate extract of PEL6 (EAE-PEL6) was subjected to gas chromatography–mass spectrometry (GC-MS) analysis, which putatively identified 32 metabolites based on GC-MS library matching, including pyrrolo [1,2-a] pyrazine-1,4-dione derivatives and triazole compounds as major constituents. The EAE-PEL6 demonstrated significant in vitro antibacterial activity against Staphylococcus aureus. In silico ADMET (absorption, distribution, metabolism, excretion, and toxicity), profiling predicted drug-likeness and pharmacokinetic properties of selected candidate compounds. Molecular docking suggested favourable binding of selected metabolites to S. aureus target proteins; however, these interactions require experimental validation. Density Functional Theory calculations indicated that CID 70504 had the lowest Highest Occupied Molecular Orbital (HOMO)–Lowest Unoccupied Molecular Orbital (LUMO) energy gap, reflecting higher electronic reactivity. Molecular electrostatic potential mapping further supported its enhanced binding propensity. Molecular dynamics simulations suggested structural stability, with Root Mean Square Deviation, Solvent Accessible Surface Area, radius of gyration, and hydrogen-bond analyses indicating stable interactions throughout the 100 ns trajectory. Overall, this study identifies P. lactis PEL6 as a promising endophytic source of anti-S. aureus metabolites and provides candidates for future purification, structural confirmation, and biological validation. Full article

This study investigates the impact of selected soil parameters and integrated fertilizer formulations on the productivity of three legume crops—mung bean, soybean, and cowpea—in order to identify the optimal strategies to maximize yields through reduced nitrogen and bio-augmentation. A five-year experiment composed of 2-year pot trials (2019–2020) and 3-year field trials (2022–2024) was conducted to assess the changes in soil parameters (N, P, K, OM, pH) and yield response of crops with varying amounts (1, 2, 4 kg) of Bradyrhizobium-based biofertilizer combined with a 25–50% reduction in mineral N fertilizer. The biofertilizer was composed of locally isolated strains, which were genetically identified in our previous reports as B. elkanii NE1-6, NE2-1, B. diazoefficiens NE1-65, Bradyrhizobium sp. NE1-19, NE1-34, and NE2-3. The results indicated that the amount of K strongly influenced yield increase for soybean (r = 0.85, p < 0.05) and mung bean (r = 0.67, p < 0.05), while the amount of N had the greatest influence on cowpea (r = 0.60, p < 0.05). Soybean yield was maximized with a 50% reduction in N fertilizer (20 kg N) combined with 2–4 kg biofertilizer, while cowpea and mung bean achieved increased yields at 25% reduced N fertilizer combined with 2–4 kg biofertilizer. This study confirms the viability of integrating Bradyrhizobium-based biofertilizer with a 25–50% reduction in mineral N fertilizer without yield loss by harnessing the efficient N-fixation ability of the strains in the consortium. Full article

The efficient extraction and purification of recombinant β-casein from Escherichia coli is a crucial step in bioprocess engineering. This study evaluates an adapted high-pressure homogenization (HPH) workflow for recombinant β-casein recovery and compares it with osmotic shock (OS) and standard HPH based on specific protein yield, estimated relative purity, and processing time. In contrast to standard HPH, which requires separate inclusion body recovery, washing, and subsequent denaturant-mediated solubilization, the adapted-HPH workflow integrates mechanical cell disruption with inclusion body recovery during homogenization. Standard HPH was evaluated in two downstream-processing runs, whereas adapted HPH and OS were each evaluated in three downstream-processing runs using separate aliquots from the same bioreactor biomass batch. Adapted HPH demonstrated higher specific yields (4.08 mg_casein/g_CDW) and required 40% less processing time compared to the OS and standard HPH methods. The specific yield obtained with adapted HPH was significantly higher than that obtained with standard HPH (p = 0.026), whereas the difference between adapted HPH and OS was not statistically significant (p = 0.086). Despite the inclusion body washing steps used for OS and standard HPH, adapted HPH achieved a slightly higher average purity than OS (63.46 ± 3.49% versus 59.38 ± 2.79%) and a purity comparable to standard HPH (68.10 ± 6.87%); however, these differences were not statistically significant. Overall, the comparative evaluation of these methods indicates that adapted HPH may provide a simplified alternative for recombinant β-casein recovery, although further validation with a larger number of independent experiments is required. Full article

Background: The fall armyworm, S. frugiperda, is a globally threatening insect pest of agricultural crops, including in Thailand. Symbiotic bacteria in the genera Xenorhabdus and Photorhabdus, which are derived from entomopathogenic nematodes, can produce diverse bioactive compounds with insecticidal activities. However, no study on Thai isolates of these symbiotic bacteria against S. frugiperda has been reported, leading to a significant gap in local biopesticide development. Methods: Two symbiotic bacterial isolates, X. miraniensis (bMH16.1_TH) and P. akhurstii (bSBR11.1_TH), were isolated from Thai entomopathogenic nematodes and cultured in LB broth at 10⁸ CFU/mL. Three bacterial fractions, i.e., whole-cell suspension, cell supernatant, and cell pellet, were prepared from each isolate. Insecticidal bioassays were conducted by topical application on second- and fifth-instar larvae of S. frugiperda (10 larvae × 5 replicates per treatment, CRD). Larval mortality was recorded daily for seven days, and median lethal time (LT₅₀) was calculated. Data were analyzed by two-way ANOVA with Duncan’s Multiple Range Test (p < 0.05). Results: The results indicated that both bacterial isolates caused significantly higher larval mortality than controls across all treatments (p < 0.05). X. miraniensis (bMH16.1_TH) showed higher virulence, achieving ~80% mortality of second-instar larvae within 24 h and 100% by day three. Whole-cell suspensions consistently produced the fastest and highest mortality with the lowest LT₅₀ values in both larval stages. Second-instar larvae were significantly more susceptible than fifth-instar larvae. The shortest LT₅₀ was recorded in second-instar larvae treated with X. miraniensis supernatant at 0.616 days, while fifth-instar larvae generally showed higher LT₅₀ values across all treatments. Conclusions: Our comparative study demonstrated that the insecticidal efficacy varied between the two symbiotic bacterial isolates and among their fractions. Whole-cell suspensions of X. miraniensis (bMH16.1_TH) produced the highest larval mortality and the smallest LT₅₀ values, particularly against early-instar larvae. These findings demonstrated that local symbiotic bacteria are promising candidates to be developed as sources of biopesticides against this insect pest. In addition, characterizing active insecticidal compounds, evaluating field efficacy, and assessing safety to non-target organisms need to be further studied to support integration of these biopesticides in sustainable pest management programs. Full article

Lactic acid bacteria (LAB) are promising oral drug delivery systems due to their probiotic properties, safety, and ability to stimulate mucosal immunity. In this study, we characterized five LAB strains, Lacticaseibacillus casei ATCC 393, Lacticaseibacillus paracasei UST1611, Lactiplantibacillus plantarum UST1611, Limosilactobacillus reuteri LR08, and Lacticaseibacillus rhamnosus GG, to assess their potential as a microbial chassis for oral drug delivery. We tested competence for transformation, plasmid stability, GFP expression under a constitutive promoter, survival under simulated gastrointestinal conditions, and survival in the gut of Danio rerio larvae. Successful transformation with the pTRKH3-ermGFP plasmid was achieved in L. casei ATCC 393, L. paracasei UST1611, and L. reuteri LR08. We also showed that the L. casei ATCC 393 strain had significantly higher protein expression than its L. paracasei UST1611 and L. reuteri LR08 counterparts. In the absence of selection, L. casei ATCC 393 and L. paracasei UST1611 retained their plasmid for 48 h. L. reuteri LR08 retained it for up to 72 h. The three transformed strains showed comparable tolerance to simulated gastrointestinal pH, though L. casei and L. reuteri were more resistant to 0.3% greater bile. In vivo testing showed the highest survival for L. casei ATCC 393 and L. paracasei UST1611 in the gut of zebrafish (Danio rerio) larvae. Overall, our results suggest that, among the five strains tested, L. casei ATCC 393 is the most promising candidate for an LAB-based microbial system for oral drug delivery. Full article

Lipases are important enzymes in the esterase family that hydrolyze ester bonds in triglycerides, producing simpler molecules. This property makes them valuable in biotechnology and environmental cleanup. In this study, lipase-producing bacteria were isolated and characterized from petroleum-contaminated soil to establish a cost-effective platform for enzyme production and bioremediation. Among the recovered isolates, Serratia liquefaciens AB1 exhibited the highest lipolytic activity and was therefore selected for further investigation. The influence of various inducer oils and agro-industrial residues on enzyme production was systematically assessed. In addition, fermentation parameters were optimized through the evaluation of different carbon and nitrogen sources to enhance lipase yield. Waste frying oil was identified as the most effective inducer, while glucose and yeast extract supported optimal enzyme production. The enzyme lipase AB1 was fully purified using CM-Sephadex C-50 chromatography, Sephadex G-100 and further characterized by SDS-PAGE, kinetic studies, and stability assays. Purification of the enzyme resulted in a specific activity of 610.92 U/mg, corresponding to a 9.42-fold increase in purity with an overall recovery of 76%. The enzyme exhibited an apparent molecular mass of approximately 64 kDa. It demonstrated optimal catalytic activity at 60 °C and pH 8 and retained substantial stability at this temperature for up to 120 min. Kinetic analysis revealed a low Km value of 30 µM, indicating strong substrate affinity, along with a Vmax of 23.89 U/mL, reflecting a high catalytic efficiency under the tested conditions. Enzyme activity was enhanced by Ca²⁺, Na⁺, and Ba²⁺, but inhibited by Mn²⁺ and Hg²⁺. These findings demonstrate the favorable biochemical properties of the purified lipase and provide a basis for future investigations into its potential application as a biocatalyst for bioremediation. Full article

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by progressive insulin resistance, impaired glucose regulation, and elevated cardiometabolic risk. Despite the availability of pharmacological therapies, long-term glycemic control remains suboptimal in many patients, highlighting the need for effective adjunctive nutritional strategies. Probiotic yogurt containing well-characterized bacterial consortia has been proposed as one such approach, given its potential to modulate gut microbiota composition, increase short-chain fatty acid (SCFA) production, improve intestinal barrier integrity, and attenuate low-grade systemic inflammation. A narrative review was conducted by searching PubMed, Scopus, and Google Scholar databases using terms related to probiotic yogurt, synbiotic yogurt, insulin sensitivity, T2DM, gut microbiota, Lactobacillus, and Bifidobacterium. Priority was given to randomized controlled trials (RCTs), meta-analyses, and systematic reviews, supplemented by mechanistically relevant preclinical studies. The reviewed evidence indicates that probiotic yogurt generally produces more consistent improvements in long-term metabolic markers, particularly glycated hemoglobin (HbA1c) and lipid profile, than in acute fasting glucose responses. Several trials also report reductions in fasting insulin and the homeostatic model assessment of insulin resistance (HOMA-IR), combined with improvement in the quantitative insulin sensitivity check index (QUICKI), particularly when yogurt is enriched with prebiotic substrates such as inulin and konjac glucomannan. Probiotic yogurt formulated with well-selected microbial consortia may serve as a safe complementary intervention for improving insulin sensitivity and overall metabolic control in T2DM patients. Full article

Bread is a global dietary staple, but its susceptibility to fungal spoilage causes substantial food waste, economic losses, and greenhouse gas emissions. Volatile organic compounds (VOCs) produced by sourdough microorganisms can contribute to the prevention of bread spoilage; however, the specific VOCs that exert the protective effect in the bread matrix have not been precisely identified. Our study investigated the antifungal activity of sourdough lactic acid bacteria (LAB) consortia, both alone and in combination with yeast and acetic acid bacteria (AAB), as well as the VOC profiles of sourdough and sourdough bread. The consortium comprising Lactiplantibacillus plantarum 9-5 and Levilactobacillus brevis 9-2 (LAB), Monosporozyma unispora R3SD1d (yeast), and Acetobacter fabarum WB and Komagataeibacter rhaeticus Ch2 (AAB) extended the mold-free shelf life of sourdough bread by 8–20 days after challenge tests. VOC analysis revealed that sourdough bread had significantly higher concentrations of ethyl esters of hexanoic and octanoic acids with 6.3- to 9.7-fold increase in peak areas after three days of refrigerated storage, assuming their decisive role in prevention of fungal spoilage. In conclusion, the use of this consortium is promising to significantly extend bread shelf life, but also to enrich the bread VOC profile. Full article

Cocoa bean quality is strongly influenced by microbial fermentation, which drives flavour development through enzymatic activity. Despite its importance, the specific microorganisms, particularly those producing pectinase, remain poorly characterized. This study aimed to identify and evaluate pectinase-producing microbes from fermenting cocoa mass and assess their impact on fermentation performance. In the first experiment, 9 bacterial and 14 yeast strains were isolated and screened on pectinase screening agar. Three yeast strains (FF1D3, FF2D1, and NA) showed high pectinolytic activity. FF1D3 and FF2D1 were identified as Pichia kudriavzevii, whereas NA showed only a low-confidence closest BLAST match to Candida orthopsilosis and was therefore not advanced as a starter culture candidate. These strains had the highest polygalacturonase activity at 24–48 h and pectin lyase activity at 48–72 h. In the second experiment, inoculating cocoa beans with these strains significantly enhanced fermentation kinetics, with yeast populations reaching log10⁹, indicating enhanced fermentation via accelerated sugar utilization. Brix values (1.97–3.11) and pH reduction (p  <  0.01) confirmed active microbial metabolism and effective acidification. Phenolic content varied significantly (p  <  0.01), with FF2D1 and combined treatments showing elevated levels due to strain-dependent enzymatic hydrolysis. The combined starter culture showed potential to improve fermentation consistency and accelerate sugar utilization. These findings highlight the potential of targeted microbial inoculation to optimise cocoa fermentation and quality. Full article

Marine-derived fungi are important reservoirs of bioactive secondary metabolites, yet the diversity of fungal producers of mycophenolic acid (MPA) remains incompletely explored. In this study, 304 fungal strains were isolated from marine sediments collected from three coastal regions of Vietnam and screened for MPA production using thin-layer chromatography, high-performance liquid chromatography, and LC-MS confirmation. Twenty-five isolates (8.22%) were identified as MPA producers and were preliminarily assigned to the fungal genera Penicillium, Aspergillus, and Cladosporium, with two isolates remaining unidentified, based on morphological characteristics. Strain MBLC9-138 was selected for detailed characterization because it represented a non-Penicillium MPA-producing isolate assigned to Cladosporium. Morphological observations and multilocus sequence analyses based on internal transcribed spacer region (ITS), actin gene (ACT), and beta-tubulin gene (TUB/TUB2) supported its identification as Cladosporium sp. MBLC9-138. HPLC analysis showed that this strain produced 463.25 mg/L MPA after 5 days of cultivation in NaCl-supplemented potato dextrose broth, while the maximum yield reached 632.03 ± 2.39 mg/L at 168 ± 12 h during the late exponential to early stationary phase. The purified MPA extract inhibited Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, and Staphylococcus aureus ATCC 33591, with MIC values of 16, 32, and 64 µg/mL, respectively. These findings identify Cladosporium sp. MBLC9-138 as a previously underreported marine fungal source of MPA, expand the known taxonomic range of MPA-producing fungi, and support further strain optimization, metabolite purification, and antibacterial characterization. Full article

Pollution by emerging contaminants like microplastic is one of the major environmental concerns. Microplastics have become ubiquitous anthropogenic pollutants of aquatic, terrestrial and atmospheric ecosystems, and can generate considerable ecological and health-related risks. Conventional remediation regimes are widely ineffective, due to the physicochemical recalcitrance of polymer matrices. Recent advances in microbial biotechnology have revealed several contrasting microbial taxa and enzyme systems, which can convert or mineralize synthetic polymers through a variety of pathways of complex biochemistry. This review summarizes the current understanding of microbial–polymer interactions, including surface colonization, biofilm-mediated depolymerization, and intracellular uptake of degradation intermediates. It also discusses recent developments in enzyme engineering, strain optimization employing the CRISPR method, and synthetic biology approaches improving catabolic efficiency. The advent of a variety of multi-omics technologies of metagenomics, transcriptomics, and metabolomics has enabled the characterization of novel hydrolases and oxidoreductases with a high potential catalytic efficiency. Advances in nanobiocatalysis, enzyme immobilization, and bioreactor technology improve the scale-up of these processes. Related molecular developments and environmental applications will promote the application of microbial biotechnology as a selective and sustainable tool for the mitigation of microplastic accumulation and the development of a circular bioeconomy that interacts positively with ecosystem resilience. Full article

The development of alternative strategies for gluten detoxification represents an important approach for the management of celiac disease and other gluten-related disorders. This study aimed to identify gluten-degrading Bacillus strains with probiotic potential by integrating enzymatic screening with comprehensive biosafety and functional characterization. A total of 45 isolates obtained from diverse ecological niches in Uzbekistan were evaluated for glutenolytic activity using an agar diffusion assay. Fifteen strains demonstrated detectable gluten hydrolysis (16–32 mm). The highest activity was observed in Bacillus cereus isolates (up to 32 mm), whereas Bacillus amyloliquefaciens and Bacillus licheniformis exhibited moderate activity (16–24 mm). However, biosafety profiling revealed pronounced hemolytic, lecithinase, and DNase activities in most B. cereus strains, along with reduced antibiotic susceptibility, which precludes their probiotic application. In contrast, B. amyloliquefaciens and B. licheniformis strains exhibited γ-hemolysis, lacked lecithinase and DNase activities, showed high susceptibility to clinically relevant antibiotics, and demonstrated satisfactory tolerance to simulated gastrointestinal conditions. None of the strains demonstrated detectable antimicrobial activity under standard in vitro conditions. Culture supernatants exhibited pronounced antioxidant activity (73.38–90.34% DPPH radical scavenging), indicating the production of extracellular bioactive metabolites. The results demonstrate functional divergence within the Bacillus genus between maximum glutenolytic capacity and probiotic safety. Species belonging to the Bacillus group, including Bacillus amyloliquefaciens, B. subtilis, and B. licheniformis, are widely recognized as safe for food and probiotic applications (GRAS and/or QPS when appropriately characterized at the strain level). Accordingly, while B. cereus strains represent promising sources of industrial gluten-degrading enzymes. B. amyloliquefaciens 6/4/2, together with selected B. subtilis and B. licheniformis strains, demonstrated the most favorable balance between glutenolytic activity and biosafety, making them the most promising candidates for further probiotic development. Full article

Mangrove sediments represent dynamic coastal microbiomes that harbor diverse microbial communities under fluctuating environmental conditions. Unlike extensively studied bacterial communities, yeast microbiomes in mangrove habitats remain poorly understood. This study evaluated the diversity, community dynamics, environmental associations, and ecological interaction networks of yeast assemblages in mangrove sediments from Central Java, Indonesia, using ITS metabarcoding and multivariate ecological analyses. Environmental DNA extracted from sediment samples was sequenced using the Illumina NovaSeq 6000 platform, followed by ASV delineation, taxonomic curation, diversity analyses, ordination, variation partitioning, and co-occurrence network inference. Malassezia-associated taxa dominated mangrove sediment yeast communities, with pronounced geographic variation in subordinate taxa among ecosystems. Alpha- and beta-diversity analyses revealed heterogeneous community patterns and compositional tendencies across mangrove sediments. Salinity, total dissolved solids, Pb, and Cu were evaluated as potential environmental gradients; however, permutation tests indicated that the measured variables did not significantly explain yeast community composition. Co-occurrence network analysis revealed predominantly positive and modular associations, with several highly connected taxa potentially contributing to network connectivity and ecological organization. These findings expand current understanding of fungal microbiome organization in tropical mangrove ecosystems while emphasizing the need for cautious interpretation of environmental drivers in DNA-based sediment metabarcoding studies. Full article

Entomopathogenic fungi of the genus Metarhizium can degrade and penetrate the insect cuticle through the coordinated action of hydrolytic enzymes, mainly lipases, proteases, and chitinases, whose production varies according to the fungal species and fermentation conditions. These enzymes can be generated via submerged fermentation and subsequently employed to enhance the insecticidal activity of fungal conidia. This study aimed to increase protease production from Metarhizium robertsii Mt015 to strengthen biological control agents based solely on fungal biomass. The culture medium composition and physicochemical parameters were optimized using a statistical design approach. Biological activity assays were then performed using Tuta absoluta larvae as the target insect and Beauveria bassiana as the reference control, tested both alone and in combination with the protease extract. Optimization identified wheat bran, casein, and an initial pH of 8–10 as the most influential variables, achieving a 5.5-fold increase in protease activity compared to the basal medium. When the protease extract was combined with B. bassiana conidia, the mortality rate reached 78.2%, significantly higher than the 55.6% achieved with B. bassiana conidia alone. Bliss independence analysis indicated that the observed larval mortality exceeded the additive expectation (Δ = 23.3 percentage points; 95% CI: 16.7–30.0), supporting a synergistic interaction between B. bassiana and the protease extract at 0.68 U/mL. These results demonstrate that enzymatic supplementation markedly improves the insecticidal performance of entomopathogenic fungi, supporting the use of enzyme-enriched formulations as a complementary strategy to strengthen biological control agents and advance the development of next-generation biopesticides. Full article