Bacillus Strains Research Articles

Lipopeptides from Bacillus atrophaeus MCM61 and melatonin suppress gray mold-induced oxidative stress in cut roses (Rosa hybrida L.) and improve vase life.

Application of melatonin and lipopeptides (LPs) derived from Bacillus strains is considered an efficient strategy to control plant diseases atboth pre and postharvest stages. However, the combined application of melatonin and LPs has not been studied yet. Therefore, the present study presents the synergistic effect of melatonin and LPs produced by Bacillus atrophaeus strain MCM61 against gray mold disease and its impact on quality parameters and vase life of cut roses. The stems of cut roses alongwith flowers were dipped in the melatonin solution at concentration (0, 0.2, 0.4, 0.6, and 0.8mM) and the results indicated thatthe vase life of flowers treated with the melatonin was enhanced compared to control. Melatonin at 0.6mM concentration showed the highest vase life of cut roses at day 8. Synergistic treatment with melatonin and LPs of B. atrophaeus MCM61 revealed that MDA and H2O2 content showed the highest decrease in cut roses. Similarly, relative water content, total phenol content, GSH content, and defense enzymes i.e., APX, SOD, PPO, POD, and CAT activities were increased in cut roses treated with co-application of B. atrophaeus MCM61 LPsand melatonin compared to single treatments and control treatment. Furthermore, the longevity of cut roses was also improved in flowers treated with a combined application of MCM61 and melatonin compared to other treatments.

Bioremediation of a Dis-Azo RB222 Dye using a Novel Bacillus Strain: Experimental and Artificial Neural Network Based Process Optimization

Bioremediation of a Dis-Azo RB222 Dye using a Novel Bacillus Strain: Experimental and Artificial Neural Network Based Process Optimization

Genomic characterization of the salt-tolerant Bacillus and Jeotgalicoccus strains reveals a diverse metabolism relevant to plant growth promotion and salt stress tolerance.

The online version contains supplementary material available at 10.1007/s13205-024-04164-7.

Host-derived Bacillus antagonistic novel duck reovirus infection by regulating gut microbiota-mediated immune responses

The Novel Duck Reovirus (NDRV) infection poses a significant health risk to ducks, primarily attributed to the absence of efficacious preventive measures. This research aimed to investigate whether the administration of isolated Bacillus could protect antagonistic NDRV infection in a Cherry Valley duck model. Four indigenous Bacillus strains from the feces of healthy ducks demonstrated promising biosafety profiles. One-day-old ducklings were inoculated intramuscularly with NDRV and subsequently subjected to a 28-day regimen of mixed Bacillus (Bac) treatment. The effects of Bac on pathological symptoms, immune response and intestinal flora were analyzed. The results showed that Bac significantly reduced weight loss, clinical symptoms, and viral loading. Moreover, Bac treatment significantly decreased neutrophils, monocytes proportion, the TNF-α, IL-1β and IL-6 expression, increased platelets, lymphocytes proportion, the IFN-β and IL-10 expression, and restored immune dysfunction. In addition, Bac has increased the relative abundance of Enterococcaceae, Lactobacillales, Bacilli, Ruminococcaceae, Clostridium and Phascolarctobacterium. Moreover, the metabolism of short-chain fatty acids (SCFAs) was further regulated, thereby enhancing the acetate content. The correlation analysis showed that a positive association between acetate levels and IFN-β expression, while a negative correlation was observed with viral loading. In conclusion, the results suggest that the anti-NDRV mechanism of Bac may involve the modulation of gut microbiota to elicit an immune response that inhibits viral infection. This study presents a novel approach for the prevention and treatment of NDRV, thereby establishing a theoretical foundation for the future development of probiotics in the prevention and treatment of NDRV.

Biochar-bacteria coupling system enhanced the bioremediation of phenol wastewater-based on life cycle assessment and environmental safety analysis

The efficient treatment of phenol wastewater is of great necessity since it induces serious pollution of water and soil ecosystems. Using biochar-immobilized functional microorganisms can innovatively and sustainably deal with the existing problem. In this study, we utilized response surface methodology (RSM) combined with life cycle assessment (LCA) to improve phenol biodegradation rate through a novel separated alkali-resistant and thermophilic strain Bacillus halotolerans ACY. Bioinformatic analysis revealed the genetic foundation of ACY to adapt to harsh environments. The characteristics of pig manure biochar (PMB) produced at varying pyrolysis temperatures (300-700 ℃) and adsorption experiment were investigated, immobilization of the phenol-degrading ACY on PMB600 under alkaline and high pollution load promoted phenol removal and extreme environment resistance, and the phenol removal rate reached 99.5% in 7d in actual phenol wastewater, which increased compared with those achieved by PMB (50.6%) and free bacteria (80.5%) alone. Scanning Electron Microscope (SEM) and Fourier transform infrared spectrometry (FTIR) observations indicated the successful bacterial immobilization on PMB600. Reusability and economic cost study further demonstrated PMB600 as an excellent carrier for wastewater treatment. LC-MS, toxicology and carbon footprint analyses demonstrated that bacterial metabolism exerted synergy with adsorption for phenol removal, while biodegradation exerted the predominant impact on the immobilized bacterial system. This study provides an eco-friendly and effective approach to treat phenol wastewater.

Biocontrol potential of endophytic Bacillus spp. associated to wild Solanaceous species and their secondary metabolites against various potato (Solanum tuberosum L.) storage diseases

Fusarium dry rot, Pythium leak and Southern blight diseases caused by various Fusarium species, Pythium aphanidermatum, and Agroathelia rolfsii, respectively, are responsible for important losses of tuber at the post-harvest stage in Tunisia. In the present study, six Bacillus strains, isolated from wild solanaceous plants, were screened for their abilities to inhibit potato pathogens in vitro and on potato tubers. Based on the dual culture assays, the whole cell suspensions of B. tequilensis SV39 and SV104, B. subtilis SV41, B. methylotrophicus SV44 and B. amyloliquefaciens subsp. plantarum SV65 exhibited potent antifungal activity against target pathogens. Significant inhibitory effects were also induced by their cell-free culture filtrates, butanolic and chloroform extracts depending on target pathogens, concentration used and bacterial strains tested. The gas chromatography-mass spectrometry (GC–MS) analysis of B. tequilensis SV39 butanolic extract revealed the highest relative abundance of phthalic acid and derivatives as major volatile compounds. The current study sheds light on the ability of all bacterial strains to reduce the lesion diameter or rot penetration by about 59-61% and 51-58%, respectively. Furthermore, B. tequilensis SV104 and SV39 were the most effective bio-agents in reducing the lesion diameter by 64.06 and 57.31%, respectively, while SV104 (B. tequilensis), SV41 (B. subtilis) and SV65 (B. amyloliquefaciens subsp. plantarum) based treatments were the most effective in decreasing the rot penetration by 54-63%. The application of these Bacillus strains constitutes a promising alternative for an efficient and safe control of potato storage diseases.

Antagonistic effect of symbiotic bacteria from entomopathogenic nematodes and Bacillus spp. against Panax ginseng root rot pathogens

Ginseng root rot is a destructive disease of Panax ginseng that seriously affects the yield and quality of P. ginseng. Based on the broad-spectrum suppression properties of entomopathogenic nematode (EPN) symbiotic bacteria, four symbiotic bacteria were selected: Xenorhabdus bovienii (Xbf), Xenorhabdus nematophila (Xna), Xenorhabdus nematophila Cxrd (Xnc) and Xenorhabdus budapestensis (Xbc). Meanwhile, six beneficial Bacillus strains (Bacillus velezensis S1A; Bacillus amyloliquefaciens H4C; Bacillus subtilis N5D; and Bacillus albus HYS, K8, and N2A) were tested. Their individual and combined effects (both in vitro and in P. ginseng slices) on fungi pathogenic to P. ginseng, Fusarium solani, Fusarium proliferatum and Fusarium oxysporum were evaluated. Xenorhabdus budapestensis had the highest suppression effects (up to 82%) on F. solani and F. oxysporum, and a 60% inhibition rate on F. proliferatum, significantly higher than Xnc, Xbf and Xna. Bacillus velezensis and B. subtilis had the strongest suppression rates on F. solani (40%). The combined effects of Xbc and B. subtilis K8 on F. solani and F. oxysporum were stronger than their individual effects. The P. ginseng slice experiment further confirmed the enhanced inhibition of Fusarium by mixing Xbc with B. subtilis K8. In conclusion, we used EPN symbiotic bacteria to suppress P. ginseng root rot and screened two EPN symbiotic bacteria that were highly effective against Fusarium spp. The combination of Bacillus strains with EPN symbiotic bacteria enhanced the suppression effect. Our results provide new biological materials and directions for biological control of P. ginseng root rot.

In Vitro evaluation of some fungicidal bioactive chemicals against fusarium spore germination and survival

The genus Fusarium are the most important pathogens associated with different plants including crop plants, fruits, vegetables, etc. causing of constrained production and productivity crops. Bioactive compounds are environmentally friendly and amenable. This study aimed to evaluate the effectiveness of some bio-active compounds derived from Bacillus strain for the in vitro control of Fusarium mold. Seven (7) isolates of the Fusarium complex were isolated from various stored fruits, vegetables and food grains using Potato Dextrose Agar (PDA) media supplemented with antibacterial agent. The growth and survival of the respective spores were challenged with supernatants of overnight-grown culture of Bacillus subtilis TC17 for 20 minutes. The supernatant prevented the germination of spores of some fungi strains in the order; F. solani, F. oxysporum, F. equiseti, F. acuminatum, F. proliferatum, F. moniliforme and F. tricinctum against control. Therefore, this research showed that the bio-active agent can be used to control the pervasive plant pathogenic fungal species with outstanding result and therefore should be developed further for registration for commercial applications.

Bacillus velezensis SS-20 as a potential and efficient multifunctional agent in biocontrol, saline-alkaline tolerance, and plant-growth promotion

The versatile strain Bacillus velezensis SS-20 was studied to determine its agricultural benefits, including its ability to antagonize fungi, promote plant growth, and tolerate saline-alkaline conditions. Firstly, strain SS-20 was found to be an antagonist of plant pathogenic fungi such as Magnaporthe oryzae, Rhizoctonia solani, and Fusarium oxysporum, with control effects up to 82.07 %, 46.57 %, and 23.09 %, respectively. The hyphae of pathogenic fungi treated with SS-20 and its fermentation product were abnormal, swollen, deformed, and distorted. Meanwhile, strain SS-20 dissolved inorganic phosphorus (phosphate solubilization efficiency, 45.95 %), and produced siderophore (siderophore units, 54.18 ± 4.19 %), and poly-γ-glutamic acid (γ-PGA) (13.35 ± 2.61 g/L). Strain SS-20 significantly increased plant height, aboveground fresh weight, and root dehydrogenase activity compared to the control treatment under non-saline conditions (p < 0.05). In addition, strain SS-20 showed significant saline-alkaline tolerance, surviving in 10 % NaCl and pH 9.5, and enhanced plant growth under simulated saline-alkali conditions. Whole-genome sequencing analysis revealed that the chromosome of B. velezensis SS-20 consists of 3,929,792-bp with 46.5 % guanine-cytosine content and 4015 coding sequences. The antiSMASH analysis identified 12 gene clusters within strain SS-20 that encode antimicrobial compounds such as surfactin, fengycin, butirosin A/butirosin B, macrolactin H, bacillibactin, difficidin, and bacilysin, thereby corroborating the strain's biocontrol capabilities. Genes related to plant growth promotion, including siderophores, γ-PGA, indole acetic acid production, phosphate solubilization, glycine-betaine production, and Na+/H+ antiporters, were also annotated. In conclusion, B. velezensis SS-20 represents a promising biotic resource for enhancing plant growth and protecting against environmental stresses.

Assessment of microbial antagonistic activity and Quorum Sensing Signal Molecule (Cyclopeptides-DKPs and N-Acyl Homoserine Lactones) detection in bacterial strains obtained from avocado thrips (Thysanoptera: Thripidae)

The control of avocado pests and diseases heavily relies on the use of several types of pesticides, some of which are strictly monitored or not internationally accepted. New sources of bioactive molecules produced by phytopathogen-inhibiting microorganisms offer an excellent alternative for the control of pests and diseases. This study explores the potential antagonistic action against phytopathogenic microorganisms, using bacterial strains obtained from avocado thrips. In addition, we detected and identified quorum sensing (QS) signaling molecules that are related to virulence factors and antibiotic production. The results showed that Bacillus, Pantoea, and Serratia strains exhibited antagonism against five fungal phytopathogens. Additionally, some bacteria also produce specific signaling molecules like N-3-(oxododecanoyl)-l-homoserine lactone (OdDHL), N-(3-oxo)-hexanoyl l-HL (OHHL), 4‑hydroxy-2-heptylquinoline (HHQ) or 2-heptyl-3,4-dihydroxyquinoline (PQS, Pseudomonas quinolone signal), cyclo(L-Phe-l-Pro), and cyclo(L-Pro-l-Tyr, which might give them antimicrobial properties. This research explores the biotechnological potential of these bacteria in fighting the diseases affecting avocados in Colombia.

Comparative Evaluation of Spores and Vegetative Forms of Bacillus subtilis and Bacillus licheniformis on Probiotic Functionality In Vitro and In Vivo.

The probiotic effects of Bacillus are strain-specific and dependent on both spore and vegetative forms, but the distinct contributions of these forms to probiotic functionality are not well understood. This study aimed to evaluate and compare the impacts of vegetative forms and spores of Bacillus subtilis and Bacillus licheniformis on probiotic functions in vitro and in vivo. We systematically assessed the anaerobic metabolic capabilities and the potential to enhance the intestinal barrier function of four Bacillus strains, leading to the selection of Bacillus subtilis X22 and Bacillus licheniformis N-3 for detailed investigation. Utilizing in vitro fermentation with murine fecal microbiota, we observed that the spores form of Bacillus licheniformis N-3 noticeably positively regulated the gut microbiota under anaerobic conditions. Concurrently, both spore and vegetative forms of Bacillus licheniformis N-3 and Bacillus subtilis X22 demonstrated the ability to prevent pathogen adhesion, reduce inflammation, combat oxidative stress, and promote cellular autophagy to reduce apoptosis in response to enterotoxigenic Escherichia coli (ETEC) infection in the IPEC-J2 cell model. As a facultative anaerobe, Bacillus licheniformis N-3 exhibited a tendency toward superior regulatory capacity in enhancing the anti-infective activity of IPEC-J2 cells in vitro. In the pathogens challenge mouse model, B. licheniformis N-3 effectively preserved the integrity of jejunal tissue and enhanced the expression of glycoproteins in goblet cells. Moreover, B. licheniformis N-3 strengthened the epithelial barrier by increasing the levels of Occludin and Claudin-1 in the jejunum, thus promoting overall intestinal health. This research offers new insights into strain selection and the life cycle utilization of Bacillus probiotics.

Potential Probiotic Bacillus Strains with Antioxidant and Antimutagenic Activity Increased Weight Gain and Altered hsp70, cxc, tnfα, il1β, and lysC Gene Expression in Clarias gariepinus

The potential probiotic properties of three Bacillus strains were studied. A probiotic supplement for the African catfish Clarias gariepinus was produced via the solid-state fermentation protocol and incorporated into the fish feed for a period of seven weeks. Since the 36th day of the experiment, all experimental groups had a statistically significant increase in their weight gain than the control group. The maximum weight gain observed in fish fed the probiotic-supplemented feed was 29.16% higher than that of the control group, and the maximum feed conversion rate improvement was 24%. Cell-free extracts from these strains showed antioxidant (11.55–27.40%) and DNA-protective (45.33–61.83%) activity in a series of in vitro biosensor tests. Further investigation into the antimutagenic activity of the strains revealed that two of them reduced the level of induced mutagenesis in an Escherichia coli model (by 33.58% and 54.35%, respectively). We also assessed the impact of probiotic strains on the expression of several key genes in the host (C. gariepinus), including hsp70, cxc, tnfα, il1β, and lysC. More than a 10-fold increase in expression rates was observed for hsp70 in gonads and liver; for cxc in muscles and gonads; for tnfα in brain, gills, and liver; for il1β in the brain, gills, gonads, and liver; and for lysC in gills, gonads, liver, and muscles. This study provides evidence that probiotics exhibiting antioxidant and antimutagenic properties can provide significant benefits in vivo within aquaculture systems. The molecular effects of these probiotics appear to be complex and tissue-specific, with both upregulation and downregulation of immune system genes observed. Nevertheless, at the organismal level, the impact was unequivocally positive in terms of aquaculture objectives, manifested as enhanced body weight gain in the fish. Consequently, these Bacillus strains warrant serious consideration as potential probiotics for this species.

Effect of the Plant Growth-Promoting Bacteria Strain Bacillus Mojavensis I4 on Potato Growth, Physiology, Tuber Yield, and Quality Under Salt Stress Conditions

Effect of the Plant Growth-Promoting Bacteria Strain Bacillus Mojavensis I4 on Potato Growth, Physiology, Tuber Yield, and Quality Under Salt Stress Conditions

Inoculation of Bacillus sp. improves root architecture, gas exchange and efficiency of nutrient use in Corymbia seedlings

The inoculation of forest species with rhizobacteria growth promoters an increasing technology capable of improving the growth and also the final quality contributing to change robust and resistant originals. The objective was to evaluate growth, root architecture, gas exchange, chlorophyll a fluorescence, chlorophyll content and nutrient use efficiency in seedlings of Corymbia inoculated with the growth promoting rhizobacteria Bacillus sp. CCMD862. The growth promotion experiment was carried out in greenhouse, using hybrid clonal seedlings of Corymbia torelliana x Corymbia citriodora. The experimental design was CRD with 2 treatments (control and rhizobacteria Bacillus sp. CCMD862) with 5 replications for each treatment and 5 replicates per treatment (Bacillus sp. CCMD862 and Control - not inoculated). noculation promoted gains in gas exchange, chlorophyll fluorescence, nutrient use, biomass variables and in all root architecture parameters in relation to control. Biometric and biomass improvements resulted in higher DQI and a global growth promotion rate 30 % higher than control plants. The strain Bacillus sp. CCMD862 is able to biostimulate seedlings of Corymbia favoring the development of the root system, gains in the photosynthetic apparatus, increases in absorption and efficient use of nutrients that resulted in robust seedlings. The results obtained in this study must be confirmed in field conditions and the future development of an inoculant could assist with rooting in Corymbia, helping to reduce mortality in the field and obtain homogeneous commercial

Construction of polylactic acid plastisphere microbiota for enhancing nitrate reduction in denitrification biofilters

Developing methods for reusing biodegradable plastics, like polylactic acid (PLA) straws, is highly needed. Here, PLAs were applied to substitute traditional commercial ceramic media (CCM) in denitrification biofilters. During long-term operation, replacing CCM with PLA significantly enhanced nitrate removal efficiency from 32.68–54.39 % to 41.64–66.26 %. Ammonia nitrogen effluent maintained below 0.5 mg/L in all reactors. PLA plastisphere shaped unique microbial communities, i.e., denitrifying bacteria Bacillus, Pseudomonas and Acidovorax preferred to inhabit or degrade PLA. Compared to CCM biofilms, PLA diminished the importance of stochastic process in biofilm assembly of PLA plastisphere. Metagenomic sequencing suggested that PLA biofilms possessed greater metabolic capabilities of denitrification and glycolysis compared to CCM. Additionally, Bacillus strain P01 isolated from PLA plastisphere demonstrated strong PLA depolymerization. Overall, this study revealed that PLA serves as carbon source and biofilm carrier, offering a promising approach to integrating plastic reuse with wastewater treatment.

INOCULATION OF MULTI-TRAIT PLANT GROWTHPROMOTING RHIZOBACTERIA FOR WHEAT GROWTH PROMOTION IN POTHOUSE CONDITIONS

Plant growth-promoting rhizobacteria (PGPR) are commonly used as inoculants to improve the growth and yield of wheat crops. Thus, the present study focused on the isolating and screening of effective isolates with multi-traits PGPR activities related to plant growth and development. Bacterial strains RA4, RA11 and RA26 were showing plant growth promoting activities like potassium solubilization, phosphate solubilization, indole acetic acid production (IAA), hydrogen cyanide production (HCN), ammonium production, zinc solubilization, anti-fungal activity. The antibiotic pattern showed that bacterial isolates RA11 and RA26 were resistant against azithromycin, ampicillin and gentamicin. Identification of multi trait PGPR was carried out by 16s rRNA sequencing. Bacterial strains RA4, RA11 and RA26 were showing 99.93 %, 100 % and 99.97 % similarity and identified as Pseudomonas paraeruginosa, Bacillus cereus and Pseudomonas aeruginosa respectively. A pot house experiment was conducted in order to check the efficacy of multi-trait PGPR as inoculants for wheat growth. In our study, bacterial strain Bacillus cereus (RA11) was showing maximum plant growth promotion in the presence of the RDK of NPK in pot house conditions. Generally, results of this study revealed that use of bio fertilizers had an effective and significant role in the growth of plants.

Insights into the role of hexa-bacterial consortium for bioremediation of soil contaminated with chlorantraniliprole

This study evaluates the efficacy of discrete bacterial consortia in bioremediating sandy loamy soil deliberately contaminated with 20 mg/kg of chlorantraniliprole (CAP). It monitors alterations in total bacterial populations and CO2 emissions, tracking residual CAP levels through UV scanning and HPLC analysis. Six active bacterial degraders (four Bacillus strains (B. subtilis subsp. subtilis AZFS3, B. pumilus AZFS5, B. mojavensis AZFS15, and B. paramycoides AZFS18), one Alcaligenes strain (A. aquatilis KZFS11), and one Pseudomonas strain (P. aeruginosa KZFS4)) were used in single or combined preparations and grown on trypticase soy broth for 24 h at 30 °C before preparing the inoculants and adjusting the bacterial cell count to 107 CFU/dwt g soil. The bacterial consortia were added to the CAP-contaminated soil and incubated for 20 days at 30 °C. The di-, tetra-, and hexa-bacterial consortia recorded the highest levels of viable bacteria, reaching their peak after 3 to 11 days of incubation. Then, they declined to the minimum levels at the end of the 20 days, which coincided with their complete removal of CAP from the soil. At the end of the incubation period (20 days), the CAP was mainly biodegraded, scoring biodegradation rates of 90.05%, 93.65%, and 98.65% for T3, T4, and T5, respectively. This concurred with the highest average CO2 production. Based on the results of the HPLC analysis, the hexa-bacterial consortium T5 demonstrated the highest rate of CAP biodegradation (99.33%) after a 20-day incubation period, resulting in the lowest residual level of CAP in the soil (0.67%). Bioinformatic analysis predicted that the CAP biodegradation pathway reached CO2 and H2O. Under optimized conditions, the hexa-bacteria consortium is the most effective CAP biodegraded and is recommended as an eco-friendly treatment for eliminating CAP pollution in the field.

Plant Growth‐Promoting Bacteria Associated With Some Salt‐Tolerant Plants

ABSTRACTGiven the benefits of bacteria associated with the rhizosphere and phytoplane of halophytes, this research focused on examining the plant growth‐promoting characteristics of bacteria isolated from Cressa cretica, Suaeda aegyptiaca, and Alhagi graecorum. From the 33 isolates tested, 9 exhibited plant growth‐promoting traits. Bacillus rugosus strain CS5 and Bacillus sp. strain SS4 exhibited the notable growth inhibition of the pathogenic fungus Fusarium oxysporum, with values of 47% and 45%, respectively. Bacillus sp. strains SS4 and CS1 demonstrated impressive results in solubilizing phosphorus and zinc, respectively, achieving concentrations of 259 and 271 mg L−1. Additionally, Staphylococcus xylosus strain SR2, Bacillus sp. strain SS4, and Bacillus paralicheniformis strain CR1 thrived in nitrogen‐free media. The Priestia filamentosa strain AL4 showed the greatest HCN production, whereas B. paralicheniformis strain CR1 was notable for higher auxin production. The Bacillus sp. strains SS4 and CS1 exhibited greater tolerance than other isolates in a medium containing 600 mM of NaCl. Additionally, inoculating these isolates into soil significantly alleviated the salinity and drought stress on Zea mays seedlings. These findings suggest that further investigation into these strains as microbial inoculants could be beneficial for mitigating salt and drought stress in plants.

Effects of Inoculation of Thermotolerant Bacillus Strains on Lignocellulose Degradation

Thise study investigated the effect of three lignocellulolytic thermophilic Bacillus strains (F11, Q1, and FP4) on lignocellulose degradation, enzymatic activities, and microbial community structure in composting. The lignin degradation rate reached 36% in the presence of the inoculant, the hemicellulose degradation rate ranged from 43% (F11) to 51% (Q1), and cellulose degradation rates reached 57% in F11 and in FP4, which were significantly higher than the control (CK). The inoculation treatment could explain 28% of the lignin degradation for all three strains. The contribution of FP4 to hemicellulose and cellulose degradation was 30% and 20%, respectively. Compared to CK, lignin peroxidase activity in the water extract of the compost had increased by 66~145% for inoculation treatments, and manganese peroxidase and laccase activity increased by 114% and 78% for Q1. The inoculation stimulated the growth of indigenous bacteria with stronger lignocellulolytic enzyme-producing ability; such shifts in microbial communities were most likely responsible for the improved lignocellulose degradation.

Enhanced vitamin B12 production by isolated Bacillus strains with the application of response surface methodology

BackgroundVitamin B12 is a crucial B-group vitamin, first isolated from the liver due to its role in combating pernicious anemia. It is distinguished by its unique and complex structure, which makes its chemical synthesis challenging and expensive. Consequently, vitamin B12 is alternatively obtained through microbial fermentations. Molasses, an affordable and safe agro-industrial waste, can be used as a carbon source for vitamin B12 production, offering a cost-effective alternative to expensive sugars in the production medium.ResultsA total of 87 yeast, actinomycete, and bacterial isolates were screened for vitamin B12 production, with 15 isolates showing high productivity. Bacillus isolates were selected for further analysis using MALDI-TOF and molecular identification. These isolates were identified as four strains of Bacillus subtilis (MZ08, JT10, BY11, and JT17), one strains of Bacillus sp. (CB09), and one strain of Peribacillus acanthi (MZ01). Genetic circuits associated with vitamin B12 production were demonstrated in a closely related strain of Peribacillus acanthi MZ01 strain. Three strains (MZ01, MZ08, and JT17) were selected for further evaluation of vitamin B12 productivity under different sugar types (glucose, sucrose, fructose, lactose, and galactose) and varying inoculum sizes. The inoculum size significantly impacted vitamin B12 production, with an increase from 5 to 10% enhancing yields. The ability of the strains to produce vitamin B12 varied depending on the type of sugar used. Peribacillus acanthi MZ01 strain showed the highest productivity and subsequently, selected for optimizing vitamin B12 production conditions using response surface methodology. Furthermore, the optimized conditions were then applied to molasses-based medium to achieve high vitamin B12 yields by MZ01 strain.ConclusionIn this study, Peribacillus acanthi was characterized for the first time as a vitamin B12 producer, demonstrating high productivity among various tested strains. The optimization of production conditions using response surface methodology, further enhanced vitamin B12 yields, showcasing the strain’s efficiency in microbial fermentations. This research also highlights the potential of using molasses as a cost-effective alternative carbon source, significantly reducing production costs.