Genus Bacillus Research Articles

Applying kitchen compost promoted soil chrysene degradation by optimizing microbial community structure

Chrysene, as a high molecular weight polycyclic aromatic hydrocarbon (PAH), has become an important factor in degrading soil quality and constraining the safe production of food crops. Compost has been widely used to amend contaminated soil. However, to date, the main components of kitchen compost that enhance the biodegradation of chrysene in the soil remain unidentified. Thus, in this study, the enhancing effect and mechanisms of kitchen compost (KC) and kitchen compost-derived dissolved organic matter (KCOM) on chrysene removal from soil were investigated through cultivation experiments combined with high-throughput sequencing technology. Additionally, the key components influencing the degradation of chrysene were identified. The results showed that KCOM was the main component of compost that promoted the degradation of chrysene. The average degradation rate of chrysene in 1% KC- and 1% KCOM-treated soil increased by 27.20% and 24.18%, respectively, at different levels of chrysene pollution compared with the control treatment (CK). KC and KCOM significantly increased soil nutrient content, accelerated humification of organic matter, and increased microbial activity in the chrysene-contaminated soil. Correlation analyses revealed that the application of KC and KCOM optimized the microbial community by altering soil properties and organic matter structure. This optimization enhanced the degradation of soil chrysene by increasing the abundance of chrysene-degrading functional bacteria from the genera Bacillus, Arthrobacter, Pseudomonas, Lysinibacillus, and Acinetobacter. This study provides insight into the identification of key components that promote chrysene degradation and into the microbial-enhanced remediation of chrysene-contaminated soil.

Mechanistic Insight into the Role of Peptides Secreted from Bacillus clausii and Future Opportunities.

Bacillus clausii is a commercial spore probiotic known to treat multiple diseases. An increased interest in exploring the nutraceutical and probiotic properties of various microorganisms has made researchers explore more about these bacteria. The current trends in the healthcare industry are majorly focused on devising new therapies to avoid drug and pathogen resistance in patients. Antimicrobial peptides have been considered a source of antibiotics for a long time. Still, getting new therapies into the market is a big challenge. Members of the genus Bacillus have been reported to have a broad spectrum of antimicrobial peptides. One of the least explored species under this genus is Bacillus clausii, concerning peptide drug therapy. The applications of Bacillus clausii in treating or preventing gut dysbiosis and respiratory infections have been largely supported in the past two decades. Yet research is lacking in explaining the pathways at molecular levels in targeting pathogens. In this mini-review, we are going to summarise the research that has been reported so far about peptide extraction from Bacillus clausii, their mode of action and advantages to mankind, and the challenges lying in the isolation of peptides.

A novel immunopharmacological biocompound

The publication is devoted to topical issues of experimental study of new biocompounds, based on the creation of a consortium of biological composite compounds – biological active substances (metabiotics) produced by strains 59T and 60T of saprophytic compounds of the genus Bacillus subtilis. These strains are very promising for the creation of hepatopicts, new medicinal substances, in the creation and development of a new pharmacological class of hepatoprotectors. Previous studies have shown the safety and hepatoprotective effect of biologically active drugs. It is worth noting that the very effective compounds are the produced biologically active substances – metabolites of bacterial origin, on the basis of which it seems appropriate to create a new class of drugs – metabiotics. The absence of vegetative probiotic cells in such compounds will reduce the additional immune load on the body. The combined use of these compounds provides a potentiated pharmacological effect. In this regard, it seemed appropriate, under the conditions of modeling toxic liver damage by carbon tetrachloride, to conduct an experimental assessment of the immunotropic effect of biologically active substances (BAS) on laboratory animals in order to confirm the effect on cellular factors of immunity. The purpose of the study was to study the effect of the combined use of dietary supplements produced by Bacillus subtilis microorganisms on indicators of cellular immunity in laboratory animals with toxic liver damage. Acute toxic hepatitis was reproduced in white laboratory rats with repeated intragastric administration of carbon tetrachloride. The comparison drug was a registered hepatoprotective drug – ursosan. The immunotropic effect was assessed using factors such as: phagocytic activity of macrophages and neutrophils (FA), NBT test, quantitative assessment of antibody-forming cells, T and B lymphocytes. As a result of the studies performed, reliable data were obtained on an increase in the number of T and B lymphocytes, antibody-forming cells, as well as an increase in FA, which confirms the activation of all parts of cellular immunity in conditions of acute toxic liver damage. The data obtained allow us to recommend the studied biocompound for the creation of new drug candidates of microbiological origin, hepatoprotective agents with immunotropic effects.

Novel Strain Bacillus velezensis LAFUEL 03: Activity Against Xanthomonas vasicola pv. vasculorum, Control of Bacterial Leaf Streak of Corn and Genome Insights into Its Antagonistic Activity

The main objective of this study was to investigate the antimicrobial activity of three putative antagonist bacterial strains of Bacillus spp. against Xanthomonas vasicola pv. vasculorum (Xvv) and their potential to control bacterial leaf streak (BLS) of corn. Additionally, the study included investigations on the genome of one of these antagonist bacteria, such as genome sequencing and mining of genes involved in biofilm formation, swarming motility, and synthesis of secondary metabolites. The growth of Xvv was inhibited by both cell suspensions and cell-free supernatants of the bacterial strains LAFUEL 01, LAFUEL 02, and LAFUEL 03 in agar diffusion tests. All three antagonist strains significantly reduced the severity of BLS in the 3rd and 4th leaves of corn plants that were artificially inoculated at the V3 growth stage under greenhouse conditions. The 16S rRNA sequencing confirmed that the antagonistic bacterial strains belong to the genus Bacillus, with LAFUEL 03 having approximately 97% similarity to B. velezensis. B. velezensis LAFUEL 03 harbors genes related to the biosynthesis of secondary metabolites, biofilm formation/regulation, and swarming motility that enhances its potential for controlling BLS in corn and suggests a promising candidate for the development of a commercial biocontrol agent.

Genomic insight on Klebsiella variicola isolated from wastewater treatment plant has uncovered a novel bacteriophage

Klebsiella variicola is considered an emerging pathogen, which may colonize a variety of hosts, including environmental sources. Klebsiella variicola investigated in this study was obtained from an influent wastewater treatment plant in the North-West Province, South Africa. Whole genome sequencing was conducted to unravel the genetic diversity and antibiotic resistance patterns of K. variicola. Whole genome core SNP phylogeny was employed on publicly available 170 genomes. Furthermore, capsule types and antibiotic resistance genes, particularly beta-lactamase and carbapenems genes were investigated from the compared genomes. A 38 099 bp bacteriophage was uncovered alongside with K. variicola genome. Whole genome sequencing revealed that the extended beta-lactamase blaLEN (75.3%) of the beta-lactamase is dominant among compared K. variicola strains. The identified IncF plasmid AA035 confers resistance genes of metal and heat element subtypes, i.e., silver, copper, and tellurium. The capsule type KL107-D1 is a predominant capsule type present in 88.2% of the compared K. variicola genomes. The phage was determined to be integrase-deficient consisting of a fosB gene associated with fosfomycin resistance and clusters with the Wbeta genus Bacillus phage group. In silico analysis showed that the phage genome interacts with B. cereus as opposed to K. variicola strain T2. The phage has anti-repressor proteins involved in the lysis-lysogeny decision. This phage will enhance our understanding of its impact on bacterial dissemination and how it may affect disease development and antibiotic resistance mechanisms in wastewater treatment plants. This study highlights the need for ongoing genomic epidemiological surveillance of environmental K. variicola isolates.

Effect of Bacillus subtilis – based microbiological preparations on the numerical composition of cultured forms of endophytic bacteria, content of mineral nutrition elements, photosynthetic pigments, as well as on chlorophyll fluorescence indices in leaves of columnar apple trees

The results of agrochemical field experiments conducted in an orchard of columnar apple tree (Malus domestica Borkh.) in the Moscow Oblast during the period of 2021–2022 are presented. The research objects were the ‘Valuta’, ‘Triumph’, and ‘President’ varieties. The effect of foliar treatments of plants with Bacillus subtilis (strain V167) and Bacillus subtilis (strain V417) strains, as well as Bacillus subtilis – based microbiological preparations “Extrasol” (strain Ch13) and “Phytosporin-M” (strain 26D) on such indicators as the microbiological and chemical composition of leaves, the content of photosynthetic pigments in leaves, and chlorophyll fluorescence indices was studied. Plant samples were analyzed using standard methodology. When applying strains and microbiological preparations based on Bacillus subtilis, the taxonomic composition of endophytic bacterial forms cultured on dense nutrient media and isolated from leaves was represented by the Bacillus genus. For comparison, when treating plants with Bacillus subtilis strain V417 and “Phytosporin-M”, the Pseudomonas genus was also detected. The number of cultivated forms of endophytic bacteria in the treated plants was consistently growing, having reached the maximum value of 406800 CFU/g in the “Extrasol” variant. Notably, the content of photosynthetic pigments in leaves depended on both the plant variety and the strain used. High values of maximal efficiency of PSII photochemistry (Fv/Fm) were observed both in experimental and control variants. A consistent increase in leaf N content was detected when applying “Extrasol”. In this respect, the ‘President’ variety showed the greatest response, i.e., a 16.1 % increase compared to the control. The ‘President’ and ‘Triumph’ varieties demonstrated an increase in leaf K content under the influence of foliar treatment of plants with the studied strains and microbiological preparations. The greatest effect of 17.2 % above the control was observed in the ‘Triumph’ variety when treated with “Extrasol”. Foliar treatments of ‘President’ and ‘Valuta’ plants with microbiological preparations contributed to increased, compared to the control, Mg contents in their leaves.

Whole genome sequencing of a Domibacillus strain from the Cuatro Ciénegas basin that tends to act as an altruist.

Domibacillus sp. 8LH is a whitish bacterium isolated from the pools of the Cuatro Cienegas Basin (CCB) in the state of Coahuila and belongs to the Bacillaceae family. It grows in circular colonies of about 6 mm in diameter and is capable of forming biofilms. This strain was identified because, in previous experiments in our laboratory, it presented altruistic interactions when co-cultured with bacteria of the genus Bacillus that participate in the nitrogen cycle. This altruistic behavior confers to this Domibacillus strain a potential use for the construction of bacterial consortia with diverse biotechnological applications.

Selection and Effect of Plant Growth-Promoting Bacteria on Pine Seedlings (Pinus montezumae and Pinus patula).

Forest cover is deteriorating rapidly due to anthropogenic causes, making its restoration urgent. Plant growth-promoting bacteria (PGPB) could offer a viable solution to ensure successful reforestation efforts. This study aimed to select bacterial strains with mechanisms that promote plant growth and enhance seedling development. The bacterial strains used in this study were isolated from the rhizosphere and endophyte regions of Pinus montezumae Lamb. and Pinus patula Schl. et Cham., two Mexican conifer species commonly used for reforestation purposes. Sixteen bacterial strains were selected for their ability to produce auxins, chitinase, and siderophores, perform nitrogen fixation, and solubilize inorganic phosphates; they also harbored genes encoding antimicrobial production and ACC deaminase. The adhesion to seeds, germination rate, and seedling response of P. montezumae and P. patula were performed following inoculation with 10 bacterial strains exhibiting high plant growth-promoting potential. Some strains demonstrated the capacity to enhance seedling growth. The selected strains were taxonomically characterized and belonged to the genus Serratia, Buttiauxella, and Bacillus. These strains exhibited at least two mechanisms of action, including the production of indole-3-acetic acid, biological nitrogen fixation, and phosphate solubilization, and could serve as potential alternatives for the reforestation of affected areas.

Microbiological Quality Assessment of Some Commercially Available Breads.

Bread is a staple, energy-rich food for people of all ages, so quality is important to consumers. In our region, most of the commercially available bread, whether packaged or unpackaged, is produced by local bakeries, so monitoring microbial levels and the types of microbes present on bread can help to draw attention to protect the final product. It can also help to ensure the food safety, quality, and shelf life of bread. The freshly baked product is microbiologically sterile. Post-process contamination affects the microbial load of bread. In this study, the microbial load of 30 different commercial bread crumbs and crusts was determined. The different types of bread with different compositions were analyzed for total viable bacteria, Escherichia coli, Staphylococcus aureus, aerobic and anaerobic spore-forming bacteria, and culturable microscopic fungi. The K-means clustering algorithm was used to cluster the different types of bread based on the number of aerobic mesophilic bacteria. Significant differences (p < 0.05) were found in the total viable bacterial count for bread crusts and crumbs. The bacterial count of bread varied between 10.00 ± 0.00-395.00 ± 52.4 CFU/g for bread crusts and 10.00 ± 0.0-310.67 ± 94 CFU/g for bread crumbs. The results of 16S rDNA sequence analysis showed that the most frequently occurring bacterial species belonged to the genus Bacillus, but species of the genus Staphylococcus were also present. Chryseobacterium spp. predominated on multigrain bread, Marinilactobacillus spp. on rustic potato bread, and Staphylococcus warneri on sliced brown potato bread. The results contribute to a better understanding of the microbial dynamics in locally produced breads from the Eastern Carpathians of Transylvania, with the aim of improving food safety, quality control, and consumer protection.

Metagenomic Analysis of Bacterial Communities in Bee Bread in Türkiye

This study aims to investigate the bacterial community structure in bee bread samples collected from 10 provinces of Türkiye using next-generation sequencing (NGS) and metagenomic analysis. Bacterial genomic DNA was extracted and sequenced using Illumina MiSeq. Bioinformatic analysis involved quality assessment, OTU classification, principal coordinate analysis (PCoA), and diversity index calculations. Heatmap and PCoA were utilized to explore the impact of locality and ecological zones on microbial diversity. Metagenomic analysis of 12 bee bread samples revealed 276,583 high-quality sequencing reads. The dominant bacterial phyla identified were Proteobacteria, Actinobacteria, Cyanobacteria, and Firmicutes. At the genus level, Streptomyces, Streptococcus, Bacillus, and Synechococcus were the most abundant, with Streptomyces and Bacillus playing key roles in the fermentation process of bee bread. The Shannon diversity index (ranging from 2.92 to 4.26) and Simpson's index (0.83 to 0.95) indicated high species diversity and relative abundance in bee bread. The study underscores the need for locality-specific approaches in beekeeping management and highlights the potential significance of beneficial bacterial taxa, particularly those involved in fermentation, in contributing to the nutritional and health properties of bee bread. These findings provide a foundation for further research on the microbial dynamics that support bee colony health.

Optimization of Screening Media to Improve Antimicrobial Biodiscovery from Soils in Undergraduate/Citizen Science Research-Engaged Initiatives.

Background/Objectives: Research-engaged academic institutions offer the opportunity to couple undergraduate education/citizen science projects with antimicrobial biodiscovery research. Several initiatives reflecting this ethos have been reported internationally (e.g., Small World, Tiny Earth, MicroMundo, Antibiotics Unearthed). These programs target soil habitats due to their high microbial diversity and promote initial screening with non-selective, nutrient media such as tryptic soy agar (TSA). However, evaluation of published outputs to date indicates that isolate recovery on TSA is consistently dominated by the genera Bacillus, Pseudomonas, and Paenibacillus. In this study, we evaluated the potential of soil extract agar to enhance soil isolate diversity and antibiosis induction outcomes in our undergraduate Antibiotics Unearthed research program. Methods: We comparatively screened 229 isolates from woodland and garden soil samples on both tryptic soy agar (TSA) and soil extract agar (SEA) for antimicrobial activity against a panel of clinically relevant microbial pathogens. Results: On one or both media, 15 isolates were found to produce zones of clearing against respective pathogens. 16S rRNA gene sequencing linked the isolates with three genera: Streptomyces (7), Paenibacillus (6), and Pseudomonas (2). Six of the Streptomyces isolates and one Pseudomonas demonstrated antimicrobial activity when screened on SEA, with no activity on TSA. Furthermore, incorporation of the known secondary metabolite inducer N acetyl-glucosamine (20 mM) into SEA media altered the pathogen inhibition profiles of 14 isolates and resulted in broad-spectrum activity of one Streptomyces isolate, not observed on SEA alone. In conclusion, SEA was found to expand the diversity of culturable isolates from soil and specifically enhanced the recovery of members of the genus Streptomyces. SEA was also found to be a superior media for antibiosis induction among Streptomyces isolates when compared to TSA. It was noted that Paenibacillus isolates' antibiosis induction demonstrated a strain-specific response with respect to the growth media used. Conclusions: The authors propose SEA inclusion of in soil screening protocols as a cost-effective, complementary strategy to greatly enhance outcomes in undergraduate/citizen science-engaged antimicrobial biodiscovery initiatives.

Ecotoxicological impacts of cadmium on soil microorganisms and earthworms Eisenia foetida: from gene regulation to physiological processes

Cadmium is a hazardous heavy metal that is commonly found in the soil and poses significant risks to soil organisms. The toxic effects of Cd on soil microorganisms and earthworms (Eisenia foetida) have been extensively studied, but most studies focused on high Cd pollution levels. Therefore, this study aims to investigate the different responses of soil organisms to moderate and low levels of Cd contamination. According to the study, the presence of 2.5 mg/kg of Cd had a significant impact on the microbial community’s composition and diversity. The relative abundance of most microbes decreased, while the abundance of Firmicutes and Actinobacteriota showed a considerable increase. The LEFSE analysis revealed that the Bacillus genus of the Firmicutes phylum can serve as a biomarker in soil contaminated with 2.5 mg/kg of Cd. At the same time, the functional analysis of PICRUSt 2 shows that microorganisms found in polluted soil have a noticeable decrease in their ability to metabolize lipids. On the other hand, our findings indicate that Cd has a detrimental effect on the biomass of earthworms and induces oxidative stress in these animals. The activation of superoxide dismutase (SOD) and catalase (CAT) enzymes in earthworms was carried out to mitigate oxidative stress. The study found a strong positive relationship between SOD and both time and Cd pollution. However, CAT exhibited inhibition throughout the later stages of the experiment, particularly when exposed to relatively higher levels of pollution. The analysis of RNA in earthworms revealed that soil Cd pollution at a concentration of 2.5 mg/kg primarily impacts the cellular structure and function of earthworms. This pollution disrupts the integrity of the cytoskeleton structure, hampers DNA replication, and compromises the precision of cell signaling. Simultaneously, when compared to the control group, several metabolic pathways exhibited abnormalities.

Comparison in Bioactive Compounds and Antioxidant Activity of Cheonggukjang Containing Mountain-Cultivated Ginseng Using Two Bacillus Genus.

In this study, the nutrients, phytochemicals (including isoflavone and ginsenoside derivatives), and antioxidant activities of cheonggukjang with different ratios (0%, 2.5%, 5%, and 10%) of mountain-cultivated ginseng (MCG) were compared and analyzed using microorganisms isolated from traditional cheonggukjang. The IDCK 30 and IDCK 40 strains were confirmed as Bacillus licheniformis and Bacillus subtilis, respectively, based on morphological, biological, biochemical, and molecular genetic identification, as well as cell wall fatty acid composition. The contents of amino acids and fatty acids showed no significant difference in relation to the ratio of MCG. After fermentation, isoflavone glycoside (such as daidzin, glycitin, and genistin) contents decreased, while aglycone (daidzein, glycitein, and genistein) contents increased. However, total ginsenoside contents were higher according to the ratio of MCG. After fermentation, ginsenoside Rg2, F2, and protopanaxadiol contents of cheonggukjang decreased. Conversely, ginsenoside Rg3 (2.5%: 56.51 → 89.43 μg/g, 5.0%: 65.56 → 94.71 μg/g, and 10%: 96.05 → 166.90 μg/g) and compound K (2.5%: 28.54 → 69.43 μg/g, 5.0%: 41.63 → 150.72 μg/g, and 10%: 96.23 → 231.33 μg/g) increased. The total phenolic and total flavonoid contents were higher with increasing ratios of MCG and fermentation (fermented cheonggukjang with 10% MCG: 13.60 GAE and 1.87 RE mg/g). Additionally, radical scavenging activities and ferric reducing/antioxidant power were significantly increased in fermented cheonggukjang. This study demonstrates that the quality of cheonggukjang improved, and cheonggukjang with MCG as natural antioxidants may be useful in food and pharmaceutical applications.

Comparative genome analysis of endophytic Bacillus amyloliquefaciens MR4: a potential biocontrol agent isolated from wild medicinal plant root tissue.

In this investigation, 396 endophytic bacterial strains from six indigenous medicinal plant species within the Xinjiang Tumor Peak National Nature Reserve were subjected to screening. The strain MR4 emerged as a noteworthy contender, demonstrating pronounced biocontrol capabilities coupled with exceptional cold tolerance. Through morphological scrutiny and comprehensive genomic sequencing, MR4 was identified as Bacillus amyloliquefaciens. Antagonistic assays revealed MR4's efficacy in suppressing the causative agents of cotton wilt and verticillium wilt, achieving inhibition rates surpassing 50%. Analyses, underpinned by PCR methodologies, indicated MR4's capacity to biosynthesize a minimum of eight distinct antimicrobial agents. The whole-genome sequencing data indicated that B. amyloliquefaciens MR4 had the genome size and GC content of 4,017,872bp and 47.14%, respectively, and 4191 coding genes were identified. The genome consists of a single chromosome and one plasmid. Moreover, it was augmented by annotations from various databases, including GO, KEGG, and COG. The pathogenicity of MR4 undergoes evaluation, while predictions concerning MR4's secondary metabolites have disclosed gene clusters for 13 varieties of these compounds, with particular emphasis on surfactins and fengycin. Comparative analyses with four paradigmatic strains shed light on MR4's genomic composition and its phylogenetic lineage within the Bacillus genus. The genomic data pertaining to MR4 have been duly submitted to the NCBI GenBank, bearing the accession numbers CP146236 (Chr1) and CP146237 (plas1). This study endeavors to furnish potent microbial resources for the biocontrol and enhancement of plant growth, thereby providing a theoretical groundwork for MR4's agronomic utilization.

Screening And Identification Of Bacterial Isolate Producing Arbutin Glycoside And Improving Its Productivity By Mutagenesis

From three sources of Iraqi soil, 30 bacterial isolates were obtained. after performing the primary isolation process, 12 isolates could produce the glycoside arbutin as an indication of the reddish-brown precipitate. When secondary isolation was conducted, it was found that two isolates, A7 and C10, gave the highest production of arbutin as a function of the concentration of the resulting compound, as it reached a concentration of Arbutin 5.3 µg/ml and 8.5 µg/ml, respectively. The diagnosis process was carried out for isolate C10 based on cultural and microscopic characteristics, as the nature of growth on the liquid medium was that it floated on the surface, and the cells formed a thin membrane with each other. Pellice as for the nature of growth on a liquid media, the colonies were spread out and flat, with irregular edges, a cream color, and a wrinkled surface, while the microscopic characteristics of the bacterial isolate were that they were positive for Gram stain and the cells were rod-shaped of medium length. The biochemical tests Vitec 2 results showed that the bacterial isolate belonged to Bacillus subtilis with a probability of 98%. Upon genetic diagnosis at the 16SrRNA level, it was found that the isolate belonged to the genus Bacillus subtilis by 100% compared to what is available in the NCBI GenBank and that exposure for 30 minutes at a wavelength of 257 nanometers (20w) and at a distance of (20) cm from the dish to ultraviolet radiation resulted in to improve the production of arbutin twice as much as the wild strain.

Effect of the complex of probiotic microorganisms of the genus Bacillus on the growth, histological structure of intestines and the resistance of sturgeon hybrid juveniles

Effect of the complex of probiotic microorganisms of the genus Bacillus on the growth, histological structure of intestines and the resistance of sturgeon hybrid juveniles

Diversity and Activity of Bacteria Cultured from a Cup-The Sponge Calyx nicaeensis.

Marine sponges are well-known for hosting rich microbial communities. Sponges are the most prolific source of marine bioactive compounds, which are frequently synthesized by their associated microbiota. Calyx nicaeensis is an endemic Mediterranean sponge with scarce information regarding its (bioactive) secondary metabolites. East Mediterranean specimens of mesophotic C. nicaeensis have never been studied. Moreover, no research has inspected its associated bacteria. Thus, we studied the sponge's bacterial diversity and examined bacterial interspecific interactions in search of a promising antibacterial candidate. Such novel antimicrobial agents are needed since extensive antibiotic use leads to bacterial drug resistance. Bacteria cultivation yielded 90 operational taxonomic units (OTUs). A competition assay enabled the testing of interspecific interactions between the cultured OTUs. The highest-ranked antagonistic bacterium, identified as Paenisporosarcina indica (previously never found in marine or cold habitats), was mass cultured, extracted, and separated using size exclusion and reversed-phase chromatographic methods, guided by antibacterial activity. A pure compound was isolated and identified as 3-oxy-anteiso-C15-fatty acid-lichenysin. Five additional active compounds await final cleaning; however, they are lichenysins and surfactins. These are the first antibacterial compounds identified from either the C. nicaeensis sponge or P. indica bacterium. It also revealed that the genus Bacillus is not an exclusive producer of lichenysin and surfactin.

Microorganisms’ Growth Inhibition in Poultry Meat Using Bacillus spp.

Meat processing enterprises are currently seeking ways to improve the efficiency of their operations. This study aimed to assess the presence of harmful microorganisms in poultry meat treated with a probiotic complex of Bacillus spp. bacteria during storage. Of the 2,516 meat samples collected from broiler chickens across six poultry processing enterprises in the Dnipropetrovsk region over three years, 1,845 samples tested positive for pathogens. Listeria spp. were isolated in 52.7% of meat samples, S. aureus in 28.7%, P. aeruginosa – in 6.9%, E. coli in 4.2%, and Salmonella spp. in 7.5%. The next stage of the study was the infection of 10 samples of poultry meat with pathogens of test cultures (Escherichia coli UNCSM - 007, Pseudomonas aeruginosa UNCSM - 012, Staphylococcus aureus UNCSM - 017, Listeria ivanovii UNCSM - 042, Salmonella Enteritidis UNCSM - 081), followed by aerosol treatment with a probiotic complex of Bacillus spp. (1.5×108 in ml (0.5 Mac Farland) administered at a dose of 1 ml per sample with daily registration of colony growth. Following pathogen contamination and a single aerosol treatment with the probiotic complex of Bacillus spp., the growth of E. coli and S. aureus was already suppressed on the second day of meat storage. The probiotic complex of Bacillus spp. was able to displace Salmonella Enteritidis on the third day and P. aeruginosa on day 4, but the growth of L. ivanovii could be observed only on day 5. The probiotic complex of Bacillus spp. formed visible biofilms from the five strains of microorganisms and remained viable for five days, forming a dense biofilm with a high accumulation rate of 4.73 D620. A distinctly noticeable ability to form microbial biofilms within three days was observed in planktonic forms of L. ivanovii up to 2.88 D620, followed by P. aeruginosa at 2.28 D620. Low biofilm density was observed for Salmonella Enteritidis (1.77 D620) and S. aureus (1.76 D620). The probiotic complex of bacteria of the genus Bacillus spp. shows potential for use in meat processing plants to prevent the growth of harmful microbial biofilms on meat products stored under refrigeration.

Diversity and Prevalence of Indigenous Soil Bacillus spp. in the Major Cabbage Growing Agroecological Zones of Uganda

Different species of genus Bacillus have been reported from different environments of the world. They are reported to play a role of soil fertility improvement, plant growth promotion and disease and pest management. Most of these reports on Bacillus species are from studies conducted outside Uganda and therefore information on the prevalence and diversity of bacillus species in Ugandan soils is scanty. This study aimed at determining the prevalence and diversity of Bacillus spp. isolated from the cabbage rhizosphere in the four major cabbage-growing agroecological zones of Uganda. The experiment was conducted in a laboratory at the College of Veterinary Medicine, Animal Resources and Biosafety Makerere University for morphological and biochemical identification of the Bacillus bacteria. DNA extraction and PCR were conducted at the College of Natural Resources Makerere University while sequencing was done at Macrogen laboratories in Korea and Inqaba Biotec in South Africa. Morphological, biochemical and genomic analyses revealed five Bacillus spp. (22 Bacillus strains) grouped as B. cereus, B. mycoides, B. thuringiensis, B. megaterium and B. bingmayongensis. B. cereus and B. megaterium were the most dominant and widely spread Bacillus spp. A phylogenetic tree indicated three major clads, showing that B. thuringiensis was closely related to B. cereus while B.bingmayongesis was closely related to B.megaterium. The B. mycoides were closely related to some B. cereus strains and B. bingmayongensis. The phylogenetic tree further showed that some Bacillus strains of the same species were distantly related. It was therefore concluded that most abundant and prevalent Bacillus spp. in Ugandan soils were B. cereus and B. megaterium. The presence and abundance of these bacillus species in the Ugandan soil presents an opportunity for soil scientists to innovatively manipulate them for use as biofertilizers and biopesticides for crop production and management. Such innovations would reduce the reliance of farmers on synthetic fertilizers that are pollutants to the environment and unhealthy to the users and consumers

Use of bacteria solubilizing phosphate, limestone, and phosphate fertilization in tifton 85 pasture

Using inoculants can be an alternative to reduce chemical fertilizers and improve the production of cultivated pastures. The objective of this work was to evaluate the use of an inoculant containing bacteria of the genus Bacillus (Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus pumilus) in a pasture of the genus Cynodon cv. Tifton 85, with and without liming and phosphating. The experiment was carried out in Vista Alegre do Prata, RS, in an area of Tifton 85 established in 2012, organized in randomized blocks with a factorial scheme 2 (with and without inoculant) x 4 (control, liming, phosphating, liming + phosphating), with four repetitions. The parameters evaluated after 49 days were plant height, production of dry and fresh mass of the aerial part, nutrient content in the tissue, neutral detergent fiber (NDF), and acid detergent fiber (ADF). At 119 days, the height of the plants and the production of the dry and fresh mass of the aerial part were evaluated. The results demonstrated that phosphate fertilization and/or liming did not influence the efficiency of using Bacillus spp. The application of Bacillus spp. increased plant height and Tifton's fresh and dry mass in the first cut, but chemical corrections did not affect these parameters. The treatments did not impact forage quality (NDF and ADF). In the second cut, only the height of the plants was greater with the application of the inoculant, suggesting the need for reapplication. Therefore, the application of Bacillus spp. favors the development of Tifton 85, maintaining forage quality.