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The bioinspired synthesis of construction material, known as biocement, represents a significant advancement in addressing the environmental sustainability issues associated with traditional cement use in the built environment. Biocement is produced through the process of microbially induced bio-mineralization (MIBM), which offers a promising alternative or supplement to conventional cement, potentially reducing its consumption. Despite extensive literature on the application of biocement in construction biotechnology, the fundamental mechanisms underlying its ability to enhance concrete quality remain poorly understood. This study focuses on the kinetics of biomineral synthesis by two Bacillus species; Bacillus megaterium RB05 and Bacillus foraminis DRG5, to identify the most effective strain for biomineralization. Bioconcrete specimens were created by adding inoculum containing Bacillus megaterium RB05 cells with a nutrient solution to the concrete mixture in a layer-by-layer approach. After 28 days of water curing, nanoparticles of CaCO3, ranging in size from 27 to 82 nm, were produced in the bioconcrete specimens. The resulting concrete, containing nanocrystalline biogenic calcite, demonstrated significant improvements in mechanical properties. Specifically, compressive and tensile strengths of the bioconcrete, tested using a universal testing machine (UTM), increased by 7.69 ± 0.08% and 22 ± 0.1%, respectively, after 72 h of curing. Additionally, the biocement was found to exhibit an organic–inorganic hybrid nature, as identified by TEM, EDAX, FESEM, FTIR, and XRD analyses. The enhanced mechanical properties were attributed to the high surface-to-volume ratio and hybrid nature of the calcite nanoparticles. The findings of this investigation are encouraging, suggesting the potential development of future green and self-sustainable construction materials or bioconcrete. [ABSTRACT FROM AUTHOR]

Salinization poses a significant challenge in agriculture, exacerbated by anthropogenic global warming. Biostimulants, derived from living microorganisms or natural extracts, have emerged as valuable tools for conventional and organic agriculture. However, our understanding of the molecular mechanisms underlying the effects of biostimulants is very limited, especially in crops under real cultivation conditions. In this study, we adopted an integrative approach to investigate the effectiveness of the combined application of plant growth‐promoting bacterium (Bacillus megaterium strain BM08) and a non‐microbial biostimulant under control conditions (normal watering) and salt stress. After confirming the yield increase under both conditions, we investigated the molecular mechanisms underlying the observed effect by measuring a number of physiological parameters (i.e., lipid peroxidation, antioxidants, chlorophylls, total phenolics and phytohormone content), as well as RNA sequencing and primary metabolite analyses. Our findings reveal that the combined effect of the microbial and non‐microbial biostimulants led to a decrease in the antioxidant response and an up‐regulation of genes involved in cytokinin biosynthesis under salt stress conditions. This, in turn, resulted in a higher concentration of the bioactive cytokinin, isopentenyladenosine, in roots and leaves and an increase in γ‐aminobutyric acid, a non‐proteic amino acid related to abiotic stress responses. In addition, we observed a decrease in malic acid, along with an abscisic acid (ABA)‐independent up‐regulation of SR‐kinases, a family of protein kinases associated with abiotic stress responses. Furthermore, we observed that the single application of the non‐microbial biostimulant triggers an ABA‐dependent response under salt stress; however, when combined with the microbial biostimulant, it potentiated the mechanisms triggered by the BM08 bacterial strain. This comprehensive investigation shows that the combination of two biostimulants is able to elicit a cytokinin‐dependent response that may explain the observed yield increase under salt stress conditions. [ABSTRACT FROM AUTHOR]

Several studies highlight the environmental and human health impacts of outdoor air pollution. However, a significant gap exists in understanding indoor air pollution in urban households. The current work aims to characterize the fan dust samples collected from households in Chandigarh, India. The five composite samples were collected from different areas, including the dining room, drawing room, bedroom, kitchen, and worship room, of different households in the same location. Samples were characterized using various analytical techniques like X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The concentration of all the measured elements was found to be relatively lower when compared with other similar studies. Ca and Fe showed a high household fraction. XRD confirmed the high fraction of calcite and quartz particles in household dust samples. In SEM analysis, circular, irregular flakes and fibrous particles indicated coal combustion particles in the household dust. Additionally, sharp edge particles showed the enrichment of minerals in the dust samples. Health risk assessment results indicated that the hazard index values for children and adult populations were within limits for non-carcinogenic and carcinogenic health risks from three exposure pathways, revealing insignificant health risks. Besides, the microbiological examination identifies Paebacillus barcinonensis and Bacillus megaterium in dining room dust, Bacillus megaterium and Bacillus circulans in dining and drawing room dust, Lysinibacillus boronitolerans in Bedroom dust, Paenibacillus species. and Bacillus species. in worship room dust, Bacillus circulance and Bacillus megaterium in the kitchen area. Human activities were strongly found to be associated with microbial and metal existence in the dust samples. Household dust, contaminated with biological and inorganic pollutants, has the potential to pose health risks to occupants. Hence, the study briefly discusses the approaches to minimize household dust and indoor air pollutants. Therefore, improving indoor air quality should be a vital component of public health protection policies for urban and rural households. [ABSTRACT FROM AUTHOR]

The development of an efficient and environmentally friendly dust suppressant is crucial to address the issue of dust pollution in limestone mines. Leveraging the synergistic microbial-induced calcium carbonate precipitation (MICP) technology involving NaHCO3 and dodecyl glucoside (APG), the optimal ratio of the dust suppressant was determined through single-factor and response surface tests. The dust suppression efficacy and mechanisms were analyzed through performance testing and microscopic imaging techniques, indicating that the optimal ratio of the new microbial dust suppressant was 20% mineralized bacteria cultured for 72 h, 0.647 mol L−1 cementing solution, 3.142% NaHCO3, and 0.149% APG. Under these conditions, the yield of calcium carbonate increased by 24.89% as compared to when no NaHCO3 was added. The dust suppressant demonstrated excellent wind, moisture, and rain resistance, as well as curing ability. More calcite was formed in the dust samples after treatment, and the stable form of the dust suppressant contributed to consolidating the limestone dust into a cohesive mass. These findings indicate that the synergistic effect of NaHCO3 and APG significantly enhanced the dust suppression capabilities of the designed microbial dust suppressant. [ABSTRACT FROM AUTHOR]

Plants can recruit beneficial microbes to enhance their ability to resist disease. It is well established that selenium is beneficial in plant growth, but its role in mediating microbial disease resistance remains poorly understood. Here, we investigated the correlation between selenium, oilseed rape rhizosphere microbes, and Sclerotinia sclerotiorum. Soil application of 0.5 and 1.0 mg kg–1 selenium [selenate Na2SeO4, Se(VI) or selenite Na2SeO3, Se(IV)] significantly increased the resistance of oilseed rape to Sclerotinia sclerotiorum compared with no selenium application, with a disease inhibition rate higher than 20% in Se(VI)0.5, Se(IV)0.5 and Se(IV)1.0 mg kg–1 treatments. The disease resistance of oilseed rape was related to the presence of rhizosphere microorganisms and beneficial bacteria isolated from the rhizosphere inhibited Sclerotinia stem rot. Burkholderia cepacia and the synthetic community consisting of Bacillus altitudinis , Bacillus megaterium , Bacillus cereus , Bacillus subtilis , Bacillus velezensis , Burkholderia cepacia , and Flavobacterium anhui enhanced plant disease resistance through transcriptional regulation and activation of plant-induced systemic resistance. In addition, inoculation of isolated bacteria optimized the bacterial community structure of leaves and enriched beneficial microorganisms such as Bacillus , Pseudomonas , and Sphingomonas. Bacillus isolated from the leaves were sprayed on detached leaves, and it also performed a significant inhibition effect on Sclerotinia sclerotiorum. Overall, our results indicate that selenium improves plant rhizosphere microorganisms and increase resistance to Sclerotinia sclerotiorum in oilseed rape. [ABSTRACT FROM AUTHOR]

In soybean production, numerous strategies are utilized to enhance seed quality and mitigate the effects of biotic and abiotic stressors. Zn-based nutrient priming has been shown to be effective for field crops, and biopriming is a strategy that is becoming increasingly important for sustainable agriculture. On the other hand, there is a lack of information about the effect of comprehensive nutrient priming and biopriming techniques on soybean seed quality and viability and seed health. This study was performed to assess the benefits of nutrient priming with Zn, biopriming with Bacillus megaterium and Bradyrhizobium japonicum (single and co-inoculation), and combination of nutrient priming and biopriming on the seed quality and viability, as well as seed infection caused by Alternaria spp. and Fusarium spp. Three different laboratory tests were employed: germination test, accelerated aging test, and seed health test. The results revealed that all tested priming treatments have a beneficial effect on seed germination, initial plant growth, and reduction of seed infection in normal and aged seeds. Additionally, comprehensive priming with Zn, Bacillus megaterium, and Bradyrhizobium japonicum reduced the occurrence of Alternaria spp. (−84% and −75%) and Fusarium spp. (−91% and −88%) on soybean seeds in the germination and accelerated aging tests, respectively, as compared to the control, which proved to be the most effective treatment in both optimal and stressful conditions. [ABSTRACT FROM AUTHOR]

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Global climate change poses a significant threat to plant growth and crop yield and is exacerbated by environmental factors, such as drought, salinity, greenhouse gasses, and extreme temperatures. Plant growth-promoting rhizobacteria (PGPR) help plants withstand drought. However, the mechanisms underlying PGPR-plant interactions remain unclear. Thus, this study aimed to isolate PGPR, Bacillus megaterium strains CACC109 and CACC119, from a ginseng field and investigate the mechanisms underlying PGPR-stimulated tolerance to drought stress by evaluating their plant growth-promoting activities and effects on rice growth and stress tolerance through in vitro assays, pot experiments, and physiological and molecular analyses. Compared with B. megaterium type strain ATCC14581, CACC109 and CACC119 exhibited higher survival rates under osmotic stress, indicating their potential to enhance drought tolerance. Additionally, CACC109 and CACC119 strains exhibited various plant growth-promoting activities, including phosphate solubilization, nitrogen fixation, indole-3-acetic acid production, siderophore secretion, 1-aminocyclopropane-1-carboxylate deaminase activity, and exopolysaccharide production. After inoculation, CACC109 and CACC119 significantly improved the seed germination of rice (Oryza sativa L.) under osmotic stress and promoted root growth under stressed and non-stressed conditions. They also facilitated plant growth in pot experiments, as evidenced by increased shoot and root lengths, weights, and leaf widths. Furthermore, CACC109 and CACC119 improved plant physiological characteristics, such as chlorophyll levels, and production of osmolytes, such as proline. In particular, CACC109- and CACC119-treated rice plants showed better drought tolerance, as evidenced by their higher survival rates, greater chlorophyll contents, and lower water loss rates, compared with mock-treated rice plants. Application of CACC109 and CACC119 upregulated the expression of antioxidant-related genes (e.g., OsCAT, OsPOD, OsAPX, and OsSOD) and drought-responsive genes (e.g., OsWRKY47, OsZIP23, OsDREB2, OsNAC066, OsAREB1, and OsAREB2). In conclusion, CACC109 and CACC119 are promising biostimulants for enhancing plant growth and conferring resistance to abiotic stresses in crop production. Future studies should conduct field trials to validate these findings under real agricultural conditions, optimize inoculation methods for practical use, and further investigate the biochemical and physiological responses underlying the observed benefits. [ABSTRACT FROM AUTHOR]

The Bacillus megaterium LVN01 species native to Colombia has demonstrated the ability to metabolize different coproducts or industrial waste (such as fique juice, cane molasses, and residual glycerol) and accumulate polyhydroxybutyrate (PHB), giving it potential in the bioplastics industry. In this research, the potential of liquid digestate as a carbon source for the production of PHA polymers in fermentation processes with this bacterial strain was evaluated. Favorably, it was found that B. megaterium utilizes the nutrients from this residual substrate to multiply appropriately and efficiently synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Bench-scale aerobic batch fermentation, under the operational conditions of this research [volume: 3 L; temperature: 30.8 °C; agitation: 400 rpm; pH: 7.0 ± 0.2; dissolved oxygen: 100% saturation; antifoam: 10% (v/v)], generated maximum values of dry cell weight (DCW) (0.56 g cell L−1) at 60 h, while the maximum PHBV yield (360 mg PHBV L−1) occurred at 16 h, which is very favorable for sustainable degradable bioplastics production. Additionally, GC–MS and NMR analyses confirmed that the PHBV copolymer synthesized by B. megaterium is made up of the monomers 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV). Furthermore, the thermal properties determined by TGA (Tonset = 283.1 °C; Tendset = 296.98 °C; Td = 290.114 °C) and DSC (Tm = °C 155.7 °C; ΔHf = 19.80 J g−1; Xcr = 18.17%) indicate that it is a thermally stable biopolymer with low percentages of crystallinity, providing flexibility that facilitates molding, adaptation, and application in various industrial sectors. [ABSTRACT FROM AUTHOR]

BACKGROUND: Carboxypeptidase is an exopeptidase that hydrolyzes amino acids at the C‐terminal end of the peptide chain and has a wide range of applications in food. However, in industrial applications, the relatively low catalytic efficiency of carboxypeptidases is one of the main limiting factors for industrialization. RESULTS: The study has enhanced the catalytic efficiency of Bacillus megaterium M32 carboxypeptidase (BmeCPM32) through semi‐rational design. Firstly, the specific activity of the optimal mutant, BmeCPM32‐M2, obtained through single‐site mutagenesis and combinatorial mutagenesis, was 2.2‐fold higher than that of the wild type (187.9 versus 417.8 U mg−1), and the catalytic efficiency was 2.9‐fold higher (110.14 versus 325.75 s−1 mmol−1). Secondly, compared to the wild type, BmeCPM32‐M2 exhibited a 1.8‐fold increase in half‐life at 60 °C, with no significant changes in its enzymatic properties (optimal pH, optimal temperature). Finally, BmeCPM32‐M2 significantly increased the umami intensity of soy protein isolate hydrolysate by 55% and reduced bitterness by 83%, indicating its potential in developing tasty protein components. CONCLUSION: Our research has revealed that the strategy based on protein sequence evolution and computational residue mutation energy led to an improved catalytic efficiency of BmeCPM32. Molecular dynamics simulations have revealed that a smaller substrate binding pocket and increased enzyme–substrate affinity are the reasons for the enhanced catalytic efficiency. Furthermore the number of hydrogen bonds and solvent and surface area may contribute to the improvement of thermostability. Finally, the de‐bittering effect of BmeCPM32‐M2 in soy protein isolate hydrolysate suggests its potential in developing palatable protein components. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, growth and enzyme production of Bacillus megaterium RB-05 was achieved at varying parameters such as temperature, incubation time, pH, carbon source and nitrogen source. Naturally occurring sand with 97% quartz was utilized as the matrix for bacterial growth and CaCO3 precipitation. The estimation of CaCO3 precipitation was done through gravimetric analysis and CaCO3 deposition was detected through EDX and SEM analysis. Furthermore, sand stabilization was determined through Drained triaxial tests. The results obtained showed maximum bacterial growth and urease activity at pH 7, 350C temperature and 48 h incubation time. Bacteria showed maximum growth with glucose as carbon source however, significant urease activity was observed with both glucose and maltose. Optimum bacterial growth was observed with ammonium chloride as the nitrogen source however, maximum urease activity was observed with ammonium sulphate. CaCO3 precipitation of treated sand showed a linear relation between CaCO3 precipitation with urease production. The EDX and SEM analysis showed CaCO3 deposition between sand particles and on the surface. Furthermore, the stress response of sand showed enhanced sand strength at maximum CaCO3 precipitation. The obtained results show the link between urease production, CaCO3 precipitation, and sand stabilization by MICP. High urease activity influences CaCO3 precipitation in the soil followed by enhanced soil strength. However, the positive results were obtained in reactor environment, further studies are required to make the technique applicable. [ABSTRACT FROM AUTHOR]

Cobalt oxide nanoparticles (Co3O4-NPs) have many applications, and today, the biosynthesis of these nanoparticles is preferred over other methods in terms of the advantages associated with it. Biosynthesis of nanoparticles (NPs) using bacteria is a novel and environmentally safe method that can be used in numerous biomedical applications. In recent years, many studies were performed on the antibiotic effects of nanoparticles and nano coatings on pathogenic agents. The purpose of this study is to determine which concentrations of cobalt oxide nanoparticles produced by Bacillus megaterium are most effective against Gram-positive and Gram-negative pathogenic bacterial strains, namely Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), respectively. The best concentration of cobalt oxide nanoparticles synthesized in this biological method at room temperature was selected from four concentrations of cobalt chloride hexahydrate salt after the characterization of nanoparticles. The necessary characteristics were investigated, such as a UV-Vis spectrometer to confirm synthesis, field emission scanning electron microscope to study the structure of nanoparticles, and X-ray diffraction for bell phase structure properties. The identification of generated nanoparticles, Fourier transform infrared spectroscopy to determine the number of components, X-ray energy dissociation spectroscopy for structural analysis and analysis of elements in the sample, vibrating sample magnetometer, and dynamic light scattering were performed to evaluate the hydrodynamic size of nanoparticles and evaluate the zeta potential to determine the surface charge. It is worth mentioning that the biosynthesis of cobalt oxide nanoparticles has not yet been performed by Bacillus megaterium. Cobalt oxide nanoparticles generated by Bacillus megaterium at an 80-mM salt concentration exhibited the highest quality. In conclusion, the assessment of cobalt oxide nanoparticles' antibacterial activity was conducted utilizing the agar disk diffusion method. The cobalt oxide nanoparticles had a significant effect and more antibacterial properties on pathogens, especially Gram-negative, than the common antibiotics used in this study. [ABSTRACT FROM AUTHOR]

It was previously discovered that, in the Gram-negative bacterium Escherichia coli growing on a minimal medium with sulfate, stress-induced growth arrest is accompanied by the release of hydrogen sulfide. The source of the sulfide is the desulfurization of intracellular cysteine as one of the ways of maintaining it at a safe level. The danger of excess cysteine is associated with its participation in the Fenton reaction, leading to the formation of highly toxic hydroxyl radicals. Using electrochemical sensors, we identified stress-induced sulfide production in the Gram-positive bacteria Bacillus subtilis and Bacillus megaterium, growing on a minimal medium with sulfate, and changes in physiological parameters such as Eh, pH, and oxygen and potassium consumption. Sulfide production was observed during growth arrest due to the depletion of glucose, ammonium or antibiotic action. The use of sensors allowed to continuously record, in growing cultures, even small changes in parameters. There were significant differences in the amount and kinetics of sulfide production between Bacillus and E. coli. These differences are thought to be due to the lack of glutathione in Bacillus. It is suggested that stress-induced sulfide production by Bacillus under the described conditions may be one of the previously unknown sources of hydrogen sulfide in nature. [ABSTRACT FROM AUTHOR]

Two series of C‐Mannich base derivatives were synthesized and evaluated through the reaction of formaldehyde, two thiazolo‐pyrimidine compounds, and various 2°‐amines. The chemical structures and inherent properties of the synthesized compounds were authenticated using a variety of spectroscopic techniques. The aseptic bactericidal potential of the compounds was assessed alongside five common bacterial microbes, with Ampicillin employed as the reference drug. Compounds 9b and 9d demonstrated comparable antibacterial activity to ampicillin against Bacillus subtilis and Bacillus megaterium, respectively, at 100 μg/mL. Furthermore, compounds 9f and 10f exhibited noteworthy action against Staphylococcus aureus (MIC: 250 μg/mL). Compounds 10b and 10f displayed excellent efficacy versus Escherichia coli, boasting (MIC: 50 μg/mL). Molecular docking studies elucidated the necessary connections and energies of molecular entities with the E. coli DNA gyrase B enzyme, a pivotal target in bacterial DNA replication. Further thermodynamic stability of the ligand‐receptor complex of 10b and 10f were further validated though 200 ns molecular dynamics simulation. The findings highlight the potential of these synthesized derivatives as effective antibacterial agents and provide valuable insights into their mechanism of action. Highlights: Two series of C‐Mannich base derivatives were synthesized by reacting formaldehyde, two thiazolo[3,2‐a] pyrimidine compounds, and seven heterocyclic amines.The antibacterial potential of the compounds was evaluated against five common bacterial pathogens, with Ampicillin as the reference drug.Compounds 9b and 9d showed comparable antibacterial activity to Ampicillin against Bacillus subtilis and Bacillus megaterium, respectively, at 100 μg/mL.Compounds 9 f and 10 f exhibited notable activity against Staphylococcus aureus, with MIC values of 250 μg/mL.Compounds 10b and 10 f displayed excellent efficacy against Escherichia coli, with MIC values of 50 μg/mL.Molecular docking studies revealed the binding interactions and energies of the compounds with the E. coli DNA gyrase B enzyme, a crucial target in bacterial DNA replication.The binding stability of promising compounds 10b and 10 f was further validated through 200 ns molecular dynamics (MD) simulations. [ABSTRACT FROM AUTHOR]

The agricultural industry is constantly searching for new solutions to increase the productivity and nutritional value of crops under various conditions. Microbial inoculants have emerged as an alternative to traditional chemical fertilisers which could enhance crop productivity in acid soils - a major problem in modern agriculture. The aim of this research was to evaluate the effects of Bacillus megaterium and Mesorhizobium sp. on the seed germination of bird’s foot trefoil and orchardgrass under low pH (in vitro), as well as the nutrient composition of plants grown in acid soil. A positive impact of bacterial inoculation on seed germination was observed at pH 5 and 6 for both plant species. The content of macro- and microelements was within the range of optimal values for both plant species. This research provides valuable insights into the potential benefits of using bacterial inoculants to improve the seed germination and nutrient composition of plants grown in acid soils.

Abstract Background Pulmonary alveolar proteinosis (PAP) is a special clinical presentation mostly associated with autoimmune disorders. Here we report a rare case of PAP secondary to infection of Bacillus megaterium. Case presentation A 58-year-old woman presented with intermittent cough and dyspnea for half a year. Chest CT scan showed “crazy paving” pattern. B. megaterium was identified by percutaneous CT-guided needle biopsy. She continuously received antimicrobial treatment since the diagnosis and follow-up examination suggested great improvement. Conclusions To our knowledge, this is the first case of B. megaterium infection presented with PAP pattern in healthy individuals. Attention should be paid on the secondary causes including rare pathogen infection when patients presented with PAP syndrome.

The Bacillus megaterium LVN01 species native to Colombia has demonstrated the ability to metabolize different coproducts or industrial waste (such as fique juice, cane molasses, and residual glycerol) and accumulate polyhydroxybutyrate (PHB), giving it potential in the bioplastics industry. In this research, the potential of liquid digestate as a carbon source for the production of PHA polymers in fermentation processes with this bacterial strain was evaluated. Favorably, it was found that B. megaterium utilizes the nutrients from this residual substrate to multiply appropriately and efficiently synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Bench-scale aerobic batch fermentation, under the operational conditions of this research [volume: 3 L; temperature: 30.8 °C; agitation: 400 rpm; pH: 7.0 ± 0.2; dissolved oxygen: 100% saturation; antifoam: 10% (v/v)], generated maximum values of dry cell weight (DCW) (0.56 g cell L−1) at 60 h, while the maximum PHBV yield (360 mg PHBV L−1) occurred at 16 h, which is very favorable for sustainable degradable bioplastics production. Additionally, GC–MS and NMR analyses confirmed that the PHBV copolymer synthesized by B. megaterium is made up of the monomers 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV). Furthermore, the thermal properties determined by TGA (Tonset = 283.1 °C; Tendset = 296.98 °C; Td = 290.114 °C) and DSC (Tm = °C 155.7 °C; ΔHf = 19.80 J g−1; Xcr = 18.17%) indicate that it is a thermally stable biopolymer with low percentages of crystallinity, providing flexibility that facilitates molding, adaptation, and application in various industrial sectors.

Bitterness in citrus juice is a common quality issue in the fruit-based beverage industry. Naringin, the dominant flavonoid responsible for bitterness in citrus fruit juice, can be mitigated by the enzyme naringinase. This study focuses on the isolation of novel naringinase-producing bacterium from mandarin orange peel, followed by the production and partial purification of naringinase. The bacterial strain exhibiting the highest enzyme production potential was identified as Bacillus megaterium AULS 1. The effects of carbon source (naringin) concentration, inducer (naringenin), pH, and temperature on naringinase production were investigated. Optimized conditions yielded a maximum naringinase production of 386.43 U mL–1. The produced enzyme was partially purified using ammonium sulfate precipitation and dialysis. The effects of pH, temperature, and metal ion concentration on the activity of the partially purified enzyme were evaluated, resulting in a highest activity of naringinase of 539.25 U mL–1 under optimized conditions. The debittering activity of the partially purified enzyme was 45.78 %. These findings demonstrate that Bacillus megaterium AULS 1 has the potential for naringinase production, and can be utilized for debittering citrus juices.

Background: Pulmonary alveolar proteinosis (PAP) is a special clinical presentation mostly associated with autoimmune disorders. Here we report a rare case of PAP secondary to infection of Bacillus megaterium. Case presentation: A 58-year-old woman presented with intermittent cough and dyspnea for half a year. Chest CT scan showed "crazy paving" pattern. B. megaterium was identified by percutaneous CT-guided needle biopsy. She continuously received antimicrobial treatment since the diagnosis and follow-up examination suggested great improvement. Conclusions: To our knowledge, this is the first case of B. megaterium infection presented with PAP pattern in healthy individuals. Attention should be paid on the secondary causes including rare pathogen infection when patients presented with PAP syndrome. [ABSTRACT FROM AUTHOR]

Coix seed is a good product for both medicinal and food use, which is highly susceptible to aflatoxin B1 (AFB1) contamination during field transport, storage, and processing. The aim of this study is to find microbial strains that can solve the problem of contamination of coix seed. In this study, the AFB1-degrading microorganism SX1-1 was isolated and identified as a Bacillus megaterium based on morphology, microscopy, and 16S rDNA sequencing. The optimum culture conditions for SX1-1 to degrade AFB1 were determined to be 12 h. The optimum degradation conditions were 72 h, 57°C, and an initial pH of 8.0. The highest degradation of AFB1 was observed in the fermentation supernatant of the SX1-1 strain, with a degradation rate of 97.45%. In addition, whole-genome sequencing analysis of this strain revealed the presence of a number of enzymes that could potentially degrade AFB1. Importantly, SX1-1 was able to degrade AFB1-contaminated coix seed in situ by 50.06% after co-culture. In conclusion, this strain had a high AFB1 degradation ability, and has great potential and great application as a biocontrol agent for AFB1 degradation of coix seed. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENT\nHIGHLIGHTSIn recent years, heavy metal pollution has become a global environmental problem and poses a great threat to the health of people and ecosystems. Therefore, strategies for the effective remediation of Cd from contaminated soil are urgently needed. In this study, ryegrass was utilized as a remediation plant, and its remediation potential was enhanced through the application of Citric Acid (CA) in conjunction with Bacillus megaterium (B. megaterium). The P3 treatment (CA + Bacillus megaterium) exhibited a significantly higher efficiency in promoting cadmium extraction by ryegrass, resulting in a 1.79-fold increase in shoot cadmium accumulation compared to the control group (CK) with no Bacillus megaterium or CA. Moreover, the P3 treatment led to an increased abundance of Actinobacteriota, Acidobacteriota, and Patescibacteria in the rhizosphere. The concentration of amino derivatives (such as betaine, sulfolithocholylglycine, N-alpha-acetyl-lysine, glycocholic acid, arginyl-threonine) showed significant upregulation following the P3 treatment. In summary, this study proposes a viable approach for phytoremediation of soil contaminated with cadmium by harnessing the mobilizing abilities of soil bacteria.Our aim was to gain a comprehensive understanding of the mechanisms involved in phytoremediation. These findings contribute to the existing knowledge by providing insights into the mechanism of phytoremediation in Cd-contaminated soil. They are expected to serve as a theoretical foundation for further elucidation of the phytoremediation mechanisms employed in Cd-contaminated soil.CA + Bacillus megaterium increased Cd accumulation in ryegrass by 1.79 times compared to CK.CA + Bacillus megaterium also significantly improved the activity of soil enzymes.CA + Bacillus megaterium significantly improved soil bacterial communities.CA + Bacillus megaterium significantly increased metabolites in the soil. [ABSTRACT FROM AUTHOR]

Stabilized enzymes are crucial for the industrial application of biocatalysis due to their enhanced operational stability, which leads to prolonged enzyme activity, cost-efficiency and consequently scalability of biocatalytic processes. Over the past decade, numerous studies have demonstrated that deep eutectic solvents (DES) are excellent enzyme stabilizers. However, the search for an optimal DES has primarily relied on trial-and-error methods, lacking systematic exploration of DES structure-activity relationships. Therefore, this study aims to rationally design DES to stabilize various dehydrogenases through extensive experimental screening, followed by the development of a straightforward and reliable mathematical model to predict the efficacy of DES in enzyme stabilization. A total of 28 DES were tested for their ability to stabilize three dehydrogenases at 30°C: (S)-alcohol dehydrogenase from Rhodococcus ruber (ADH-A), (R)-alcohol dehydrogenase from Lactobacillus kefir (Lk-ADH) and glucose dehydrogenase from Bacillus megaterium (GDH). The residual activity of these enzymes in the presence of DES was quantified using first-order kinetic models. The screening revealed that DES based on polyols serve as promising stabilizing environments for the three tested dehydrogenases, particularly for the enzymes Lk-ADH and GDH, which are intrinsically unstable in aqueous environments. In glycerol-based DES, increases in enzyme half-life of up to 175-fold for Lk-ADH and 60-fold for GDH were observed compared to reference buffers. Furthermore, to establish the relationship between the enzyme inactivation rate constants and DES descriptors generated by the Conductor-like Screening Model for Real Solvents, artificial neural network models were developed. The models for ADH-A and GDH showed high efficiency and reliability (R² > 0.75) for in silico screening of the enzyme inactivation rate constants based on DES descriptors. In conclusion, these results highlight the significant potential of the integrated experimental and in silico approach for the rational design of DES tailored to stabilize enzymes. [ABSTRACT FROM AUTHOR]

This study developed a highly sensitive microbiological method utilizing a novel microtiter plate to screen 10 sulfonamides in chicken muscles, eggs, and prawns. This plate was fabricated from agar incorporating trimethoprim and spread with Bacillus megaterium. After residue detection by bioassay, the same test solutions were analyzed by LC-MS/MS for accurate identification and quantification. It also proved eco-friendly compared to using other quantitative methods. The residual drugs were extracted with McIlvaine buffer and purified using an Oasis® MCX cartridge. A triethylamine/methanol/water (0.5:75:24.5, v/v/v) mixture was used as the eluate. The obtained LOD values of the bioassay ranged from 5 to 25 µg kg−1 allowing the detection of the target drugs at the MRLs established in Japan. Adhering to ISO/IEC 17025 standards, the performance of the bioassay was evaluated. Based on the inhibition zone size in bioassay results, quality control yielded a Z score within ±2, indicating reasonable control over the screening process. Proficiency testing of a chicken muscle sample spiked with sulfadimidine demonstrated the inhibition zone detection of the bioassay and quantified value alignment of LC-MS/MS with reference values. In a surveillance study of 91 samples, sulfamethoxazole was detected in one prawn sample. [ABSTRACT FROM AUTHOR]

Concrete cracks in roads and infrastructure are ubiquitous due to environmental factors, fatigue, and material degradation. Applying bacteria with self-healing capabilities in concrete matrices is proposed as a solution. These bacteria, activated by water and oxygen ingress, produce calcium carbonate through biomineralization. They are improving structural integrity while reducing the adverse effects of chemical and water infiltration. The quantity of Bacillus bacteria to be added to the concrete mixture is an integral part of the standardization of the self-healing mechanism. 105 - 108 cells/mL of spores experienced improvement in mechanical properties and self-healing efficiency. Various Bacillus strains, such as Bacillus sphaericus, Bacillus subtilis, and Bacillus megaterium, are typically utilized in self-healing. The by-product of biomineralization, calcium carbonate, is an autonomous crack and pore sealer, which can be evaluated via SEM, XRD, and XDS. The study highlights the testing methodologies used to examine calcite deposition. Also, it reiterates the importance of urease activity evaluation before bacterial propagation to confirm the occurrence of the biomineralization process. Moreover, the article reiterates the bacteria's history, origin, and pathogenicity, bridging the gap concerning bacteria propagation safety and the need for industry-accepted standards and certification procedures. The transition from laboratory experiments to large-scale implementation is advocated to demonstrate bacterial concrete's sustainability and economic feasibility for broader industry adoption. Finally, bacteria concrete is a ground-breaking approach that unites construction and biology for long-term sustainable transportation materials and construction. [ABSTRACT FROM AUTHOR]

This study delves into the innovative application of a novel bacterial and enzyme mixture alone or combined with aeration in mitigating emissions from pig slurry storage and explores their impacts on the methane (CH4), carbon dioxide (CO2), and ammonia (NH3) emissions from stored pig slurry. A dynamic chamber was used in this research to assess the efficacy of the treatments. Biological additives (HIPO-PURÍN) of specific microbial strains were tested (a mixture ofof Bacillus subtilis, Bacillus megaterium, Bacillus licheniformis, Bacillus amyloliquefacien, and Bacillus thuringiensis) alone and combined with an aeration system (OXI-FUCH). Controlled experiments simulated storage conditions, where emissions of ammonia, methane, and carbon dioxide were measured. By analyzing the results statistically, the treatment with HIPO-PURÍN demonstrated a significant reduction in CH4 emissions by 67% and CO2 emissions by 60% with the use of biological additives, which was increased to 99% and 87%, respectively, when combined with OXI-FUCH aeration, compared to untreated slurry. Ammonia emissions were substantially reduced by 90% with biological additives alone and by 76% when combined with aeration. The study was driven by the need to develop sustainable solutions for livestock waste management, particularly in reducing emissions from pig slurry. It introduces techniques that significantly lower greenhouse gases, aligning with circular economy goals and setting a new standard for sustainable agriculture. Furthermore, there is a need to validate that farmers can independently manage pig slurry using simple and effective treatments techniques with profound environmental benefits, encouraging broader adoption of climate-conscious practices. [ABSTRACT FROM AUTHOR]

Graphene and graphene oxide have shown good antibacterial activity against different bacterial species due to their unique physicochemical properties. Graphene oxide (GO) has been widely used to load metallic and metal oxide nanoparticles (NPs) to minimize their surface energy during processing and preparation, hence reducing their aggregation. In this work, GO was effectively synthesized and coated with different concentrations of zinc hydroxide Zn (OH)x using the precipitation method to prepare a GO/Zn (OH)x hybrid composite. The Zn (OH)x NPs and GO/Zn (OH)x nanocomposites were synthesized and characterized using various methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Coating GO with Zn (OH)x NPs resulted in improved aggregation of Zn (OH)x NPs as well as enhanced antibacterial activity of GO against Gram-positive and Gram-negative bacteria. Additionally, the effect of Zn (OH)x coating on the antibacterial properties of the GO/Zn (OH)x composite was systematically investigated. The synergistic effects of GO and Zn (OH)x NPs resulted in enhanced antibacterial properties of the composites compared to the pristine GO material. In addition, increasing the Zn (OH)x wt. % concentration led to an increased inhibition zone of the GO/Zn (H)x composite against Bacillus megaterium and E. coli bacteria. [ABSTRACT FROM AUTHOR]

Heparosan, an unsulfated polysaccharide, plays a pivotal role as a primary precursor in the biosynthesis of heparin—an influential anticoagulant with diverse therapeutic applications. To enhance heparosan production, the utilization of metabolic engineering in nonpathogenic microbial strains is emerging as a secure and promising strategy. In the investigation of heparosan production by recombinant Bacillus megaterium, a kinetic modeling approach was employed to explore the impact of initial substrate concentration and the supplementation of precursor sugars. The adapted logistic model was utilized to thoroughly analyze three vital parameters: the B. megaterium growth dynamics, sucrose utilization, and heparosan formation. It was noted that at an initial sucrose concentration of 30 g L−1 (S1), it caused an inhibitory effect on both cell growth and substrate utilization. Intriguingly, the inclusion of N‐acetylglucosamine (S2) resulted in a significant 1.6‐fold enhancement in heparosan concentration. In addressing the complexities of the dual substrate system involving S1 and S2, a multi‐substrate kinetic models, specifically the double Andrew's model was employed. This approach not only delved into the intricacies of dual substrate kinetics but also effectively described the relationships among the primary state variables. Consequently, these models not only provide a nuanced understanding of the system's behavior but also serve as a roadmap for optimizing the design and management of the heparosan production method. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is a critical nutrient for plant growth, yet its uptake is often hindered by soil factors like clay minerals and metal oxides such as aluminum (Al), iron (Fe), and calcium (Ca), which bind P and limit its availability. Phosphate-solubilizing bacteria (PSB) have the unique ability to convert insoluble P into a soluble form, thereby fostering plant growth. This study aimed to assess the efficacy of inoculation of Bacillus megaterium B119 (rhizospheric) and B. subtilis B2084 (endophytic) via seed treatment in enhancing maize yield, grain P content, and enzyme activities across two distinct soil types in field conditions. Additionally, we investigated various mechanisms contributing to plant growth promotion, compatibility with commercial inoculants, and the maize root adhesion profile of these strains. During five crop seasons in two experimental areas in Brazil, Sete Lagoas-MG and Santo Antônio de Goiás-GO, single inoculations with either B119 or B2084 were implemented in three seasons, while a co-inoculation with both strains was applied in two seasons. All treatments received P fertilizer according to plot recommendations, except for control. Both the Bacillus strains exhibited plant growth-promoting properties relevant to P dynamics, including phosphate solubilization and mineralization, production of indole-3-acetic acid (IAA)-like molecules, siderophores, exopolysaccharides (EPS), biofilms, and phosphatases, with no antagonism observed with Azospirillum and Bradyrizhobium. Strain B2084 displayed superior maize root adhesion compared to B119. In field trials, single inoculations with either B119 or B2084 resulted in increased maize grain yield, with relative average productivities of 22 and 16% in Sete Lagoas and 6 and 3% in Santo Antônio de Goiás, respectively. Co-inoculation proved more effective, with an average yield increase of 24% in Sete Lagoas and 11% in Santo Antônio de Goiás compared to the non-inoculated control. Across all seasons, accumulated grain P content correlated with yield, and soil P availability in the rhizosphere increased after co-inoculation in Santo Antônio de Goiás. These findings complement previous research efforts and have led to the validation and registration of the first Brazilian inoculant formulated with Bacillus strains for maize, effectively enhancing and P grain content. [ABSTRACT FROM AUTHOR]

Aims This study explores the potential of cadmium (Cd)-resistant bacteria, specifically Bacillus megaterium A14, to decrease Cd accumulation in peanuts, a crop susceptible to metal uptake from contaminated soils, by understanding the bacterium's impact on plant Cd absorption mechanisms. Methods and Results Through pot experiments, we observed that A14 inoculation significantly increased peanut biomass under Cd stress conditions, primarily by immobilizing the metal and reducing its bioavailability. The bacterium effectively changed the distribution of Cd, with a notable 46.53% reduction in the exchangeable fraction, which in turn limited the expression of genes related to Cd transport in peanuts. Additionally, A14 enhanced the plant's antioxidant response, improving its tolerance to stress. Microbial analysis through 16S sequencing demonstrated that A14 inoculation altered the peanut rhizosphere, particularly by increasing populations of Firmicutes and Proteobacteria, which play crucial roles in soil remediation from heavy metals. Conclusion The A14 strain effectively counters Cd toxicity in peanuts, promoting growth through soil Cd sequestration, root barrier biofilm formation, antioxidant system enhancement, suppression of Cd transport genes, and facilitation of Cd-remediating microorganisms. [ABSTRACT FROM AUTHOR]

Background and aims: Invasive plants may interact with arbuscular mycorrhizal fungi (AMF) and mutualistic rhizosphere bacteria such as Bacillus mutualists, which are known to be influenced by soil nutrient levels. They interact in the rhizosphere, thereby enhancing and altering plant growth; however, few studies have compared the specific interactions between AMF and Bacillus under different soil nutrient levels. To elucidate these mechanisms, we examined the effect of the interaction between AMF and Bacillus on the growth of invasive Flaveria bidentis in both nutrient-rich and -deficient soils. Methods: Pot cultures of invasive F. bidentis and native Eclipta prostrata were grown in monoculture and a mixture under different nutrient levels. Mono/coinoculation with an AMF (Rhizoglomus intraradices) and Bacillus megaterium (BM) was conducted to test their effect on the growth of F. bidentis under different nutrient levels. Results: The effect of RI and BM on F. bidentis varied according to different soil nutrient levels. RI promoted the growth of F. bidentis by absorbing nitrogen from the soil regardless of nutrient level, and the growth of F. bidentis increased in conjunction with the AMF colonization rate. However, the influence of BM on the growth of F. bidentis was promotive in nutrient-rich soils and inhibitive in nutrient-deficient soils depending on soil nutrient levels. Meanwhile, compared with the monoinoculation of RI on F. bidentis, coinoculation with RI and BM in nutrient-deficient soil inhibited F. bidentis growth for BM and decreased its AMF colonization rate. Monoinoculation and the coinoculation always inhibited E. prostrata growth when competing with F. bidentis under different nutrient levels. Conclusions: RI and BM promoted the competitive growth ability of F. bidentis by inhibiting E. prostrata growth at different soil nutrient levels, suggesting that F. bidentis may employ a different mechanism to enhance its competitive ability under different nutrient levels. [ABSTRACT FROM AUTHOR]

Mango is the most important and commercially grown fruit crop in India. The area under mango is increasing rapidly but the limited availability of genuine planting material is the most important bottleneck in the expansion of the area. The application of liquid plant growth promoting rhizomicrobial consortia (PGPR) at the nursery stage will enhance the seedling vigour and graft success. Hence, an experiment was conducted at the College of Horticulture, Hiriyur during the academic year 2022-23. The experiment was laid out in Completely Randomized Design with eight treatments and three replications. In this study, liquid PGPRs were applied to the media (soil, sand and FYM @ 3:1:1), the different PGPRs viz., Control- (T1), Azotobacter chroococcum (T2), Bacillus megaterium (T3), Frateuria aurantia (T4), Azotobacter chroococcum + Bacillus megaterium (T5), Azotobacter chroococcum + Frateuria aurantia (T6), Bacillus megaterium + Frateuria aurantia (T7), Azotobacter chroococcum + Bacillus megaterium + Frateuria aurantia (T8). Among different treatments, T8 has showed significantly maximum sprout success (82.22 % and 84.44 % at 30 and 60 days after grafting), survival per cent (84.55 %), sprout length (9.30 cm), sprout girth (4.76 mm), number of leaves (15.37), leaf length (14.08 cm) and leaf breadth (3.29 cm) at 120 days after grafting. Hence, it is concluded that the mango rootstocks treated with Azotobacter chroococcum, Bacillus megaterium and Frateuria aurantia resulted in better physiological growth and graft success. [ABSTRACT FROM AUTHOR]

Sustainable management practices are crucial for the longevity of a monoculture vineyard, especially in the context of a changing climate. Therefore, soil management practices in a vineyard (T: tillage, T+FYM: tillage + farmyard manure, G: grass strips, G+NPK1: grass strips + rational rates of NPK, and G+NPK2: grass strips + higher rates of NPK) were tested in a temperate climate of Slovakia (Central Europe) under specific soil conditions (Rendzic Leptosol). We investigated the influence of continuous cropping on soil chemical properties and microbial communities during the dry and warm year of 2022. The results showed that the soil pH was higher by 19%, 21%, 24% and 13% in T, T+FYM, G and G+NPK1, respectively, compared to G+NPK2. The lowest soil organic matter (SOM) content was found in T, and it increased in the following order: T < T+FYM < G+NPK2 < G+NPK1 < G. Similarly, the lowest abundance of soil culturable bacteriota was found in T and it increased in the following order: T < T+FYM = G+NPK2 < G+NPK1< G. Culturable bacteriota was identified using mass spectrometry (MALDI-TOF MS Biotyper). The most numerous species group was Bacillus, followed by Lactobacillus > Staphylococcus > Pseudomonas. The most frequently isolated species were Bacillus megaterium (16.55%), Bacillus cereus (5.80%), Bacillus thuringiensis (4.87%), and Bacillus simplex (4.37%). Positive relationships between SOM and soil culturable bacteriota were found in the G and G+NPK1 treatments. Temperature also affected soil culturable bacteriota in all soil management practices, most significantly in G+NPK1. Overall, the best scenario for the sustainable management of a productive vineyard is the use of grass strips. [ABSTRACT FROM AUTHOR]

Bacillus volatiles to control fungus and root-knot nematodes are a topic of great interest among researchers due to their safe and environmentally friendly nature. Bacillus megaterium GIUBAM-2020 showed high nematicidal activity against Meloidogyne incognita, with 92% mortality compared with control and antifungal activity against Fusarium oxysporum by producing a 3 cm in vitro mycelial inhibition zone. Pure volatiles produced by Bacillus. megaterium GIUBAM-2020 was identified through gas chromatography and mass spectrometry (GC–MS). Among fourteen volatile organic compounds (VOCs), only one volatile compound, i.e., 2-(Ethyl-imidazol-yl) acetic acid hydrochlorid, showed strong nematicidal and antifungal activity with a mortality rate of 95% at 0.3 ng/mL after 72 h and 100% inhibition zone of fungus at 1.5 µg/mL, respectively. The VOCs-induced severe oxidative stress in nematodes, which caused rapid death. Moreover, in the presence of Bacillus megaterium GIUBAM-2020 the disease index decreased in tomato seedlings as compared to single application of F. oxysporum and M. incognita. Moreover, genes responsible for plant growth promotion SlCKX1, SlIAA1, Sipin6 and Exp18 showed an upsurge in expression, in tomato plants treated with bacterial antagonistic and challenged with the disease complex of Fusarium oxysporum and Meloidogyne incognita. Furthermore, the defence-related genes (PR1, PR5) in infested tomato plants were upregulated after treatment with Bacillus megaterium GIUBAM-2020. These findings suggest Bacillus megaterium GIUBAM-2020 possesses excellent biocontrol potential against Meloidogyne incognita and Fusarium oxysporum, by upregulating the key genes involved in plant growth promotion, and the defense mechanism. Therefore, it is concluded Bacillus megaterium GIUBAM-2020 efficiently controls Meloidogyne incognita and Fusarium oxysporum-infested tomato plants wilt disease complex. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Soil Sciences & Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sulfolipid sulfoquinovosyl diacylglycerol (SQDG), produced by plants, algae, and cyanobacteria, constitutes a major sulfur reserve in the biosphere. Microbial breakdown of SQDG is critical for the biological utilization of its sulfur. This commences through release of the parent sugar, sulfoquinovose (SQ), catalyzed by sulfoquinovosidases (SQases). These vanguard enzymes are encoded in gene clusters that code for diverse SQ catabolic pathways. To identify, visualize and isolate glycoside hydrolase CAZY‐family 31 (GH31) SQases in complex biological environments, we introduce SQ cyclophellitol‐aziridine activity‐based probes (ABPs). These ABPs label the active site nucleophile of this enzyme family, consistent with specific recognition of the SQ cyclophellitol‐aziridine in the active site, as evidenced in the 3D structure of Bacillus megaterium SQase. A fluorescent Cy5‐probe enables visualization of SQases in crude cell lysates from bacteria harbouring different SQ breakdown pathways, whilst a biotin‐probe enables SQase capture and identification by proteomics. The Cy5‐probe facilitates monitoring of active SQase levels during different stages of bacterial growth which show great contrast to more traditional mRNA analysis obtained by RT‐qPCR. Given the importance of SQases in global sulfur cycling and in human microbiota, these SQase ABPs provide a new tool with which to study SQase occurrence, activity and stability. [ABSTRACT FROM AUTHOR]

Aerobic composting is one of the most typical biological processes to decompose organic wastes into organic fertilizers or soil amendments. However, the existing composting has commonly suffered from severe nitrogen loss and long composting periods. Therefore, the additives are required to reduce the composting period and nitrogen loss. Taking the mixture of cow dung and straw as the research material, this study aims to explore the nitrogen loss during rapid composting. The experiment utilized magnetized water (T1), magnetized water combined with biochar (T2), magnetized water combined with ferrous sulfate (T3), and magnetized water combined with Bacillus megaterium (T4), with a control group designated as CK, for a 25-day aerobic composting. The results showed that the high-temperature periods for CK, T1, T2, T3, and T4 were 3- 5, 2-8, 1-8, 4-8, and 2-8 d, respectively. All T1, T2, T3, and T4 were extended the high-temperature period of composting, compared with the CK. The temperature in the T1 treatment coincided with the ambient temperature from day 14 to day 25 of composting, without the secondary fermentation, thereby shortening the composting period. T1, T2, and T4 increased the highest temperature during composting. The most significant effect of T3 was achieved at the maximum temperature of 64.5℃. The total nitrogen content of each treatment group at the end of composting increased by 14.04%, 18.89%, 37.56%, 36.27%, and 28.47%, respectively, compared with the initial total nitrogen content of composting. The total nitrogen content increased the most in the T3 treatment, compared with the CK. The total ammonia emissions in each treatment group were 8.12, 4.37, 6.60, 7.32, and 3.95 g/d, respectively, during composting. The T4 treatment emitted the least ammonia, while the CK was the most. The T3 treatment reduced the pH of the compost during the whole process, whereas the low pH reduced the NH3 emissions. The T4 treatment promoted the nitrate nitrogen content and GI value, with the GI value reaching 110.03% at the end of composting. As such, nitrogen functional genes were then determined to explore the effects of different microbial communities on nitrogen and nitrogen transformation during microbiological composting. The T2 treatment promoted the absolute abundance of the nitrogen cycling gene gdhA, and then suppressed the relative abundance of Actinobacteria, for the high nitrogen cycling. The T3 treatment promoted the absolute abundance of the nitrogen-fixing gene nifH and the nitrogencycling gene gdhA, indicating the relative abundance of Proteobacteria. Additionally, structural equations showed that T2 treatment shared a significant negative effect on ammonia emissions, while ammonia emissions had a significant positive effect on total nitrogen loss. T3 treatment had a significant negative effect on pH, and then pH had a significant positive effect on ammonia emissions, whereas, the ammonia emissions had a significant negative effect on total nitrogen loss. Therefore, the biochar was used to adsorb ammonia for less ammonia emissions, thereby reducing the nitrogen loss. Ferrous sulfate was used to lower the pH of the compost, thus reducing ammonia emissions and nitrogen loss. Magnetized water combined with biochar showed the best nitrogen retention and ideal degree of maturation in the rapid composting, in terms of composting temperature, total nitrogen content, absolute abundance of nitrogen functional genes, relative abundance of microorganisms, and structural equation [ABSTRACT FROM AUTHOR]

Background: Microbially induced calcium carbonate precipitation has been extensively researched for geoengineering applications as well as diverse uses within the built environment. Bacteria play a crucial role in producing calcium carbonate minerals, via enzymes including carbonic anhydrase—an enzyme with the capability to hydrolyse CO2, commonly employed in carbon capture systems. This study describes previously uncharacterised carbonic anhydrase enzyme sequences capable of sequestering CO2 and subsequentially generating CaCO3 biominerals and suggests a route to produce carbon negative cementitious materials for the construction industry. Results: Here, Bacillus subtilis was engineered to recombinantly express previously uncharacterised carbonic anhydrase enzymes from Bacillus megaterium and used as a whole cell catalyst allowing this novel bacterium to sequester CO2 and convert it to calcium carbonate. A significant decrease in CO2 was observed from 3800 PPM to 820 PPM upon induction of carbonic anhydrase and minerals recovered from these experiments were identified as calcite and vaterite using X-ray diffraction. Further experiments mixed the use of this enzyme (as a cell free extract) with Sporosarcina pasteurii to increase mineral production whilst maintaining a comparable level of CO2 sequestration. Conclusion: Recombinantly produced carbonic anhydrase successfully sequestered CO2 and converted it into calcium carbonate minerals using an engineered microbial system. Through this approach, a process to manufacture cementitious materials with carbon sequestration ability could be developed. [ABSTRACT FROM AUTHOR]

Simultaneous application of modified Fe3O4 with biological treatments in remediating multi-metal polluted soils, has rarely been investigated. Thus, a pioneering approach towards sustainable environmental remediation strategies is crucial. In this study, we aimed to improve the efficiency of Fe3O4 as adsorbents for heavy metals (HMs) by applying protective coatings. We synthesized core-shell magnetite nanoparticles coated with modified nanocellulose, nanohydrochar, and nanobiochar, and investigated their effectiveness in conjunction with bacteria (Pseudomonas putida and Bacillus megaterium) for remediating a multi-metal contamination soil. The results showed that the coatings significantly enhanced the immobilization of heavy metals in the soil, even at low doses (0.5%). The coating of nanocellulose had the highest efficiency in stabilizing metals due to the greater variety of surface functional groups and higher specific surface area (63.86 m2 g-1) than the other two coatings. Interestingly, uncoated Fe3O4 had lower performance (113.6 m2 g-1) due to their susceptibility to deformation and oxidation. The use of bacteria as a biological treatment led to an increase in the stabilization of metals in soil. In fact, Pseudomonas putida and Bacillus megaterium increased immobilization of HMs in soil successfully because of extracellular polymeric substances and intensive negative charges. Analysis of metal concentrations in plants revealed that Ni and Zn accumulated in the roots, while Pb and Cd were transferred from the roots to the shoots. Treatment Fe3O4 coated with modified nanocellulose at rates of 0.5 and 1% along with Pseudomonas putida showed the highest effect in stabilizing metals. Application of coated Fe3O4 for in-situ immobilization of HMs in contamination soils is recommendable due to their high metal stabilization efficiency and suitability to apply in large quantities. [ABSTRACT FROM AUTHOR]

The study materialized at the Plant Protection Directorate, Ministry of Agriculture, Iraq to know the effects of adding plant growth-promoting microorganisms (PGPM) (Azospirillum brasilense, Lysinibacillus fusiformis, Rhizobium ciceri CP-93, Pseudomonas fluorescens, Bacillus megaterium, and Trichoderma harzianum) as biofertilizers with 25% mineral fertilizer in wheat crops using the wheat cultivar IPA-99. The laboratory study included isolating and identifying Lysinibacillus, which showed no antagonism among these microorganisms in vitro. The study results revealed that the T2 treatment was superior in most of the traits under analysis, including the number of tillers (4.00 tillers plant-1 ), spike length (10.50 cm), number of spikelets per spike (19.50 spikelets spike-1 ), weight of 100 grains (3.50 g), and the number of grains per spike (35.43 grains spike-1 ). The said treatment also excelled in the attributes, such as the grain content of nitrogen (4.870%), phosphorus (1.943%), potassium (4.156%), and protein in the grain (30.43%). The T2 outperformed all treatments, except for the biological yield characteristic, where treatment T5 (62.30 g plant-1 ) excelled, and the harvest index, with treatment T1 (23.10%) excelled. However, they did not differ significantly from treatment T2. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrates (PHBs) are biopolymers that are good green alternative for synthetic carbon-based polymers, and are also one of the most researched members of the Polyhydroxyalkanoates (PHA) family. In this study, a gram-positive bacterial strain Bacillus megaterium LSRB 0103 was isolated from Pallikaranai Marshland, Chennai, India. Primary screening using Sudan Black dye revealed the presence of intracellular PHB granules. Minimal Davis Media (MDM) which was used or PHB production gave a yield of 0.7107 g/L. Subsequently, using response surface methodology (RSM), a central composite design (CCD) model was designed for media optimization having cornstarch, urea, and pH as independent variables. The findings of the CCD model were fitted into a second-order polynomial equation. The RSM model predicted the maximum PHB yield of 0.93 g/L, at these independent variable levels, cornstarch, 5 g/L; urea, 2.1 g/L; and pH 7.0; while the experimental PHB yield was 0.94 g/L, with a percentage error of 1.1%. This study is the first-time report of production of PHB by Bacillus megaterium using cornstarch and urea as substrate. [ABSTRACT FROM AUTHOR]

Background: Cowpea (Vigna unguiculata L.) an important and commonly grown kharif pulse crop in India for vegetable, grain, forage and green manuring. Considering the adverse effects of chemical fertilizers, bio-inoculants should be encouraged as natural nutrient source. Methods: Three indigenous bio-inoculants viz., Rhizobium sp., Bacillus megaterium and Glomus mosseae were evaluated in a field experiment which was conducted during kharif season 2020 to study the influence of bioinoculants on growth and yield of cowpea. The experiment was laid out in randomized block design (RCBD) with ten treatments replicated thrice. Result: The application of microbial consortia significantly influenced the number of pods bearing branches, number of nodules, fresh weight of nodules, chlorophyll content, plant nitrogen and phosphorus content and microbial activities in the cowpea rhizosphere. The present study concluded that combined application of bio-inoculants (Rhizobium, PSB, AM fungi) can save 25 per cent of recommended dose of fertilizer by sustaining the crop yield and improving the soil health. [ABSTRACT FROM AUTHOR]

The strength and durability properties of the recycled aggregate concrete (RAC) have been affected by the cracks and the weak interfacial transition zone (ITZ) of the recycled coarse aggregates (RCA). However, the mechanical and physical features of RCA can be improved by microbially induced calcite precipitation (MICP). Therefore, immobilization techniques were used to protect and maintain the high efficiency of Bacillus bacteria for the formation and precipitation of calcium carbonates in self‐healing concrete over a period of time. The objective of the present study was to show the viability of the immobilized bacterial consortium‐enhanced RCA to form self‐healing cracks. Further, the self‐healing capability of enhanced RCA was investigated along with two other immobilization methods, that is, RCA and hydrated lime and brick powder (HBr)‐immobilized bacteria. The experimental results show that the increase in the bio‐deposition time improved the physical and mechanical properties of the RCA. Further, subsequently 56 days of the healing incubation period, the immobilized consortium‐enhanced RCA concrete specimens completely healed the cracks of width 0.58 mm. However, the equivalent cracks of width 0.56 mm were also recovered by the HBr immobilized bacterial cultures. Furthermore, the field emission scanning electron microscope (FESEM), energy dispersive spectroscopy (EDS) and X‐ray diffraction (XRD) analysis revealed that the existence of precipitation at the crack surface was calcium carbonate with a regular cubic‐shaped and lamellar layer morphology. The outcomes of the current study show that consortium‐enhanced RCA has promising potential to develop self‐healing concrete with self‐repaired and improved durability properties in the concrete construction field. [ABSTRACT FROM AUTHOR]

The field experiment to standardise the nutrient management practice in pigeon pea (APK1) was conducted in randomised block design with eight treatments comprising of different nutrient sources and methods of application, at College of Agriculture, Vellayani, Thiruvananthapuram. Significant variations were recorded in growth parameters, yield attributes, yield, nitrogen uptake and protein content of seeds. The treatment involving application of 100 % N + 50 % P + 50 % K + P solubiliser + K solubiliser in soil resulted in the significantly tallest plants (109.70 cm) and maximum number of branches per plant (6.5) at harvest, average pod weight (0.62 g) and seed yield (1.48 t ha-1). Seed protein content was also maximum in the treatment, indicating that the integrated package of 100 per cent recommended dose of nitrogen and substitution of 50 per cent each of phosphorus and potassium with P solubiliser (Bacillus megaterium) and K solubiliser (Bacillus sporothermodurans) can be recommended for pigeon pea cultivation in the southern laterites of Kerala. [ABSTRACT FROM AUTHOR]

Agarwood oil is one of the costliest essential oils used in perfumery, medicine and aroma. Production of the oil traditionally involves a soaking/fermentation step. Studies have indicated a definite role of the diverse microorganisms growing during the open soaking step, and in the emergent aroma of the essential oil. However, the temporal nature of fermentation and a key functional aspect i.e., the enzymatic properties of the microbes from the fermentation basin have not been studied yet. A total of 20 bacteria and 14 fungi isolated from fermentation basins located in Assam, India, at different soaking periods classified as early (0–20 days), medium (20–40 days) and late (40–60 days) clearly pointed towards an early fungal domination followed by succession of bacteria. The physico-chemical transformations of the wood are controlled by enzymatic properties (cellulase, xylanase, amylase and lipase) of the isolates. The results indicated a strong lignocellulosic substrate modulation potential in the four isolates, viz- Purpureocillium lilacinum (0.354 mg/mL), Mucor circinelloides (0.331 mg/mL), Penicillium citrinum (0.324 mg/mL) and Bacillus megaterium (0.152 mg/mL). The highest culturable abundance (CFU/mL) was found in M. circinelloides (2 × 109) among fungi and B. megaterium (4.5 × 109) among bacteria. The highest cellulase activity was shown by P. lilacinum (0.354 mg/mL) while xylanase and lipase by M. circinelloides (0.873 and 0.128 mg/mL). An interesting revelation was that a substantial proportion of the isolates (70% bacteria and 78% fungi) were positive for lipase activity. This is the first report on the "culturable microbiome" of the agarwood fermentation basin from a temporal and functional bioactivity perspective. [ABSTRACT FROM AUTHOR]

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