Bacterium Bacillus Research Articles

Bacterial composition and cultural dynamics of microgreens-associated microbiota during selective enrichment for Listeria monocytogenes.

Widely-regarded as a so-called "superfood", microgreens have become an increasingly significant food crop from both nutritional and agricultural standpoints. However, similar to other produce commodities that are also cultivated using modernized indoor-farming methods, there have been mounting concerns over the potential risks of consuming microgreens contaminated by Listeria monocytogenes. To gain insights into the microbial properties of microgreens, this study characterized the bacterial composition of fresh microgreen retail products using amplicon sequencing of 16S rRNA genes. Dominated by Gammaproteobacteria, a total of 36 shared genera were identified as putative constituents of the microgreen core microbiome. By monitoring the dynamics of microgreen-borne bacteria undergoing a Listeria-selective cultural enrichment procedure, it was revealed that, regardless of the presence or absence of L. monocytogenes, off-target bacteria of the Klebsiella and Enterococcus genera were significantly enriched from microgreens by the primary enrichment step, with the secondary enrichment step continuing to promote the expansion of Enterococcus population. While Listeria was generally neither the most-enriched nor the dominant taxon in cultures sampled at different enrichment stages, significant enrichment of Lysinibacillus and Bacillus bacteria were detected in microgreens contaminated with L. monocytogenes, suggesting they could be co-enriched in competition with Listeria.

Carbon-mediated modulation pathways of phytotoxicity in chicken manure composting.

Compost phytotoxicity affects the safety of organic fertilizers returned to the field, thus hindering the breeding cycle, so it is essential to reduce the compost phytotoxicity. The phytotoxicity of compost was estimated utilizing the germination index (GI) and the aqueous substances (organics and ions) present in compost correlated closely with GI. This study assessed the effect of carbon additives from different plant sources (mushroom substrates (MS), cornstalks (CS) and garden substrates (GS)) on maturity parameters (temperature, pH, EC, C/N), content of aqueous carbon and nitrogen matters, salt ions, heavy metal ions, and microbiome of piles when composting with chicken manure and especially focused on their effect on GI. Results showed that all additives significantly improved GI (85.25%-106.28%). The primary factors influencing seed germination were Mg2+ and SO42- in CM compost, acetic acid and NH4+ in CM+MS compost, humic acid in CM+CS compost, and dissolved total nitrogen in CM+GS compost. During composting, the growth of heavy metal passivating bacteria (Bacillus) and organic matter degrading bacteria (Desemzia and Turicibacter) can be promoted by decreasing aqueous carbon and nitrogen substances (volatile fatty acids, NH4+, dissolved total nitrogen, amino acids) and increasing the content of humic acid, which improved the composting environment and provided favourable conditions for the germination of seeds, thereby increasing GI. Therefore, GS showed the best potential for accelerating degradation of organic matter and improving GI during composting with chicken manure.

Treatment of Cigarette Butts: Biodegradation of Cellulose Acetate by Rot Fungi and Bacteria

This study demonstrated the biodegradation of two different brands of cigarette butts (CBs), which are primarily composed of cellulose acetate, by four distinct microorganisms. These included the white rot fungus Pleurotus ostreatus, the brown rot fungus Lentinus lepideus, and the bacteria Bacillus cereus and Pseudomonas putida. After 31 days of treatment, weight loss measurements revealed a mass loss of 24–34%, where B. cereus exhibited the greatest efficacy in terms of mass loss for both brands of CBs. Fourier-Transform Infrared Spectroscopy (FTIR), confocal microscopy, and scanning electron microscopy (SEM) confirmed changes in the surface of the CBs, attributable to structural wear and material breakdown, indicating effective biodegradation by the evaluated microorganisms. Furthermore, the analyses confirmed changes in the surface of the CBs, attributable to structural wear and material breakdown, indicating effective biodegradation by the evaluated microorganisms.

Characterization and Selection of Potential Starters of Bacillus Sp. Involved in the Fermentation of Néré Seeds (Parkia biglobosa) in Côte d'Ivoire

Aims: The present study highlights about Bacillus sp. starter strains to control fermentation of Parkia biglobosa (néré) seeds. Place and Duration of Study: Between February and August 2023, this work was performed at Laboratory of Biochemistry, Microbiology and Valorization of Agroresources, of the Agropastoral Management Institute, which is part of Peleforo Gon Coulibaly University (Korhogo, Côte d'ivoire). Methodology: Fermented néré seeds were collected from soumbara producers in the Korhogo region in northern Côte d'Ivoire. Néré seeds were subjected to a physicochemical analysis to determine the pH, titrable acidity, moisture, dry matter and ash content. These fermented seeds were used for the isolation and enumeration of Bacillus bacteria. Production of extracellular enzymes and the influence of stress conditions were carried out on these strains to select potential starters. Results: The study of the physicochemical analysis of fermented néré seeds showed that these seeds have a pH of 6.59 ± 0.04, close to neutrality, with a very low titrable acidity of 0.06 ± 0.00%. The moisture content of the néré seeds is 38.76 ± 0.13% with a high dry matter content of 61.24 ± 0.22% coupled with a low ash content of 3.18 ± 0.05%. Thirty-three (33) Gram-positive bacilli were isolated from néré seeds with a microbial load of 7.1 log10 cfu/g. The production of extracellular enzymes and the influence of stress conditions led to the selection of five Bacillus strains (BS 08, BS 14, BS 19, BS 22 and BS 31) as potential starters. Conclusion: The control of the fermentation of néré seeds involves selecting strains with the best potential. Thus, five Bacillus sp. Isolates (BS 08, BS 14, BS 19, BS 22 and BS 31) were selected as potential starters for obtaining a soumbara of exceptional nutritional and organoleptic quality.

Identification of Meloidogyne panyuensis (Nematoda: Meloidogynidae) infecting Orah (Citrus reticulata Blanco) and its impact on rhizosphere microbial dynamics: Guangxi, China.

Root-knot nematode disease severely affects the yield and quality of the mandarin variety Citrus reticulata Blanco "Orah" in Guangxi, China. Nevertheless, the pathogen and the effects of this disease on microbial communities remain inadequately understood. This study identified the root-knot nematode Meloidogyne panyuensis in the rhizosphere of infected Orah using morphological and molecular biological methods. Soil chemical properties indicated that organic matter, total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), total potassium (TK), and available potassium (AK) were significantly higher in the rhizosphere soil of M. panyuensis-infected Orah than in that of healthy plants. The relative abundance of the bacteria Bacillus, Sphingomonas, and Burkholderia-Caballeronia-Paraburkholderia, as well as the fungi Lycoperdon, Fusarium, Neocosmospora, Talaromyces, and Tetragoniomyces, was elevated in the rhizosphere soil of M. panyuensis-infected plants. Furthermore, organic matter, TN, available nitrogen (AN), TP, AP, TK, and AK exhibited positive correlationswith these bacteria and fungi in the rhizosphere soil of M. panyuensis-infected Orah. Potential biocontrol strains, such as Burkholderia spp., were identified by comparing the differences in rhizosphere microbial composition between healthy Orah and M. panyuensis-infected Orah. Our findings provide a foundation for the early warning and prevention of root-knot nematode disease in Orah.

Synthesis, Spectroscopy and Biological Studies of Copper and Silver Complexes Derived from 2-Substituted Amino Propanoic Acid

Synthesis of copper and silver complexes were prepared from novel Schiff base ligand. These synthesized ligand and their metal complexes were characterized by elemental analysis, FT-IR, 1H NMR, UV-Vis and Mass spectrometry. The coordination of amino nitrogen, phenolic oxygen, and carboxylato oxygen atoms is shown by the infrared spectra.The Schiff bases and its complexes were screened for their in vitro antibacterial and antifungal studies against the bacteria Pseudomonas Aeruginosa (PA, Gram -ve), Bacillus Cirroflagellosus (BC, Gram +ve), Penicillium Notatium (PN) and Aspergillus Niger (AN) strains. The results of the antibacterial investigation show that the copper and silver complexes possess more potent bactericide and fungicide properties than the ligand.

Applying a computer model to evaluate the evolution of resistance by western corn rootworm to multiple Bt traits in transgenic maize.

Western corn rootworm, Diabrotica virgifera virgifera (LeConte) (Coleoptera: Chrysomelidae), is a major pest of maize in the United States. Transgenic maize producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) have been used to manage this pest since 2003. Refuges of non-Bt maize have been used to delay resistance to Bt maize by western corn rootworm, and are planted in conjunction with maize producing single or multiple (i.e., pyramids) Bt toxins. Two Bt toxins, Cry3Bb1 and Gpp34/Tpp35Ab1, were used individually before being combined as a pyramid, at which point resistance had already evolved to Cry3Bb1. Pyramids targeting western corn rootworm therefore contained at least one toxin to which resistance had evolved. Western corn rootworm has now evolved resistance to all four commercially available Bt toxins used for rootworm management. We used laboratory and field-generated data to parameterize a deterministic model to simulate the effectiveness of refuges and Bt pyramids to delay resistance to Bt maize in western corn rootworm. Resistance to the pyramid of Cry3Bb1 with Gpp34/Tpp35Ab1 evolved more rapidly when resistance to Cry3Bb1 was already present. This effect arose when model conditions affecting initial resistance allele frequency, inheritance of resistance, and fitness costs were varied. Generally, resistance evolved faster when initial resistance allele frequencies were higher, inheritance of resistance was nonrecessive, and fitness costs were absent, which is consistent with previous models that simulated resistance evolution. We conclude that new transgenic pyramids should pair novel, independently acting toxins with abundant refuges to minimize the risk of rapid resistance evolution.

Mycotoxin Biodegradation by Bacillus Bacteria—A Review

Mycotoxins are toxic secondary metabolites produced by various types of fungi that are known to contaminate various food products; their presence in the food chain poses significant risks to human and animal health and leads to enormous economic losses in the food and feed industry worldwide. Ensuring food safety and quality by detoxifying mycotoxin is therefore of paramount importance. Several procedures to control fungal toxins have been extensively investigated, such as preventive measures, physical and chemical methods, and biological strategies. In recent years, microbial degradation of mycotoxins has attracted much attention due to its reliability, efficiency, and cost-effectiveness. Notably, bacterial species from the Bacillus genus have emerged as promising candidates for mycotoxin decontamination owing to their diverse metabolic capabilities and resilience in harsh environmental conditions. This review manuscript aims to provide a summary of recent studies on the biodegradation of fungal toxins by Bacillus bacteria, thereby illustrating their potential applications in the development of mycotoxin-degrading products.

Cry1Ac toxin binding in the velvetbean caterpillar Anticarsia gemmatalis: study of midgut aminopeptidases N.

The velvetbean caterpillar Anticarsia gemmatalis is one of the main soybean defoliators in Brazil. Currently, the main biopesticide used to control insect pests worldwide is the bacteria Bacillus thuringiensis (Bt), which produces entomopathogenic Crystal toxins (Cry) that act in the midgut of susceptible insects, leading them to death. The mode of action of Cry toxins in the midgut involves binding to specific receptors present on the brush border of epithelial cells such as aminopeptidase N (APN), alkaline phosphatase (ALP), cadherin, and others. Mutations in these receptors, among other factors, may be involved in the development of resistance; identification of functional Cry receptors in the midgut of A. gemmatalis is crucial to develop effective strategies to overcome this possible scenario. This study's goal is to characterize APNs of A. gemmatalis and identify a receptor for Cry1Ac in the midgut. The interaction of Bt spores with the midgut epithelium was observed in situ by immunohistochemistry and total aminopeptidase activity was estimated in brush border membrane vesicle (BBMV) samples, presenting higher activity in challenged individuals than in control ones. Ten APN sequences were found in a A. gemmatalis' transcriptome and subjected to different in silico analysis, such as phylogenetic tree, multiple sequence alignment and identification of signal peptide, activity domains and GPI-anchor signal. BBMV proteins from 5th instar larvae were submitted to a ligand blotting using activated Cry1Ac toxin and a commercial anti-Cry polyclonal antibody; corresponding bands of proteins that showed binding to Cry toxin were excised from the SDS-PAGE gel and subjected to mass spectrometry analysis, which resulted in the identification of seven of those APNs. Quantitative PCR was realized to compare expression levels between individuals subjected to sublethal infection with Bt spores and control ones, presenting up- and downregulations upon Bt infection. From these results, we can infer that aminopeptidases N in A. gemmatalis could be involved in the mode of action of Cry toxins in its larval stage.

Bacillus amyloliquefaciens MZ895491: an endophytic bacterium as potential biocontrol agent in integrated pest management of fall armyworm in maize

ABSTRACT The fall armyworm, Spodoptera frugiperda is a major pest of maize crops and necessitates effective control measures. Excessive use of chemical pesticides often results in the development of resistant insect populations and environmental contamination, highlighting the need for environmentally friendly substitutes. This research aimed to estimate the potential of maize (COH6) apoplastic fluid bacterium Bacillus amyloliquefaciens (MZ895491), as a biocontrol agent against second instar S. frugiperda larvae under laboratory and pot culture conditions. The results suggest that the presence of B. amyloliquefaciens in the artificial diet could reduce the growth and development of S. frugiperda larvae. Metabolic profiling of extracellular components of B. amyloliquefaciens revealed the presence of numerous defensive and anti-feeding metabolites. A study conducted in pots demonstrated that foliar application of B. amyloliquefaciens to 5 d old maize resulted in a significant increase in antioxidant activity (83.3%), chlorophyll content (63.3%) and phenolic content (81.3%) in the leaves of 35 d old maize after 24 h of S. frugiperda infestation. Feeding bioassay further indicated significant reduction in the feeding capacity of S. frugiperda larvae on maize inoculated with B. amyloliquefaciens. The study observed that a metabolic modification in maize leaves likely led to reduced growth in larvae during the whole plant bioassay. This suggests that foliar application of B. amyloliquefaciens may effectively serve as one of the biocontrol agents against Spodoptera frugiperda. The application appears to alter the feeding behaviour of the larvae and modify maize leaf metabolism.

Two New Inner-sphere Pt(II) Thiosemicarbazone Schiff Base Complexes Immobilized into Magnetic Nanoparticles: Synthesis, Characterization, and Biological Investigations

This study explores the synthesis, characterization, and biological investigations of two new Pt(II) thiosemicarbazone complexes immobilized in magnetic nanoparticles (MNPs). MNPs exhibit distinctive physical and chemical properties that enhance their interactions with biological targets. These traits make them particularly useful, especially when combined with drugs, increasing therapeutic effectiveness while also serving as efficient diagnostic tools in imaging techniques. The two Pt(II) complexes are represented by the formulas [Pt(HL1)(H2O)]Cl and [Pt(HL2)(H2O)2]Cl. The ligand, H2L1 signifies (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazine-1-carbothioamide, while H2L2 stands for (Z)-N-ethyl-2-(2-oxoindolin-3-ylidene)hydrazine-1-carbothioamide. The ligands and their Pt(II) complexes were characterized through various techniques, including elemental analysis, mass spectrometry, thermal analysis, powder X-ray diffraction (XRD), FT-IR, NMR, and UV–visible spectroscopy. The two complexes form a square planar geometry, in which H2L1 performs as a mononegative tridentate while H2L2 acts as a mononegative bidentate. Density Functional Theory (DFT) calculations were utilized to investigate the molecular configurations of the ligands and its Pt(II) complexes. The UV–visible and fluorescence spectroscopy techniques were employed to examine the interactions between Pt(II) complexes and Bovine Serum Albumin (BSA). DNA fragmentation studies on the Pt(II) complexes were performed and showed that [Pt(HL2)(H2O)2].Cl complex is the strongest degraded on the DNA. [Pt(HL1)(H2O)]Cl and [Pt(HL2)(H2O)2]Cl complexes were immobilized into MNPs to produce Pt(L1)/MNPs and Pt(L2)/MNPs, respectively. Pt(L1)/MNPs and Pt(L2)/MNPs were identified using FT-IR, PXRD, SEM, TEM, EDX, and UV-spectroscopy. In vitro cytotoxicity tests on these compounds against MCF-7 cell line is applied. Additionally, the antimicrobial activity against two gram + ve bacteria (Bacillus subtilis and staphylococcus aureus), and two gram −ve bacterial strains (Escherichia coli and Salmonella typhi) was investigated. Furthermore, the antioxidant properties (DPPH) of the investigated compounds were assessed. The results of the study indicated that the [Pt(HL2)(H2O)2].Cl complex exhibited a higher biological potency compared to both the [Pt(HL1)(H2O)2].Cl complex and their respective ligands. When Pt(II) complexes were incorporated into the MNPs, a significant increase in their biological activity was noted, especially for Pt(L2)/MNPs, which exhibited the strongest antibacterial and anticancer effects.

Arsenic Stress Mitigation Using a Novel Plant Growth-Promoting Bacterial Strain Bacillus mycoides NR5 in Spinach Plant (Spinacia oleracea L.).

Present study aimed to identify arsenic (As)-resistant bacterial strains that can be used to mitigate arsenic stress. A bacterium Bacillus mycoides NR5 having As tolerance limit of 1100 mg L-1 was isolated from Nag River, Maharashtra, India. It was also equipped with plant growth-promoting (PGP) attributes like phosphate solubilization, siderophores, ammonia, and nitrate reduction, with added antibiotic tolerance. Furthermore, scanning electron microscopy (SEM) and transmission electron micrograph (TEM) suggested biosorption as possible mechanisms of arsenic tolerance. A strong peak in FTIR spectra at 3379.0 corresponding to amine in As-treated NR5 also indicated metal interaction with cell surface protein. Amplification of arsenic reductase gene in NR5 further suggested intracellular transformation of As speciation. Moreover, As tolerance capability of NR5 was shown in spinach plants in which the bacterium effectively mitigated 25 ppm As by producing defense-related proline molecules. Evidence from SEM, TEM, and FTIR, concluded biosorption possibly the primary mechanism of As tolerance in NR5 along with the transformation of arsenic. B. mycoides NR5 with PGP attributes, high As tolerance, and antibiotic resistance mediated enhanced As tolerance in spinach plants advocated that the strain can be a better choice for As bioremediation in contaminated agricultural soil and water.

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.

Synthesis, characterization, DFT computational studies and biological activity of transition metal complexes derived from 4-(((6-nitrobenzo[d]thiazol-2-yl)imino)methyl)benzene-1,3-diol

A series of Co(II), Ni(II), Cu(II), Zn(II) complexes have been synthesized with a benzothiazole azo dye containing tridentate (NNO) donor ligand 4-(((6-nitrobenzo[d]thiazol-2-yl)imino)methyl)benzene-1,3-diol derived from 2-amino-6-nitrobenzothiazole and 2,4-dihydroxybenzaldehyde. The structures of the novel ligand and metal complexes were identified and confirmed via various spectroscopic techniques (FT-IR,1H NMR,13C NMR, UV-Vis, mass spectrometry), TGA-DTA, powder X-ray diffraction, and DFT calculations. The optimal structural parameters and chemical reactivity of the ligand and metal complexes have been investigated using Density Functional Theory calculations (DFT/B3LYP,6-31G** and LanL2DZ basis sets) to provide insight about their frontier molecular orbitals (FMO) and molecular electrostatic potential (MESP). In vitro DPPH radical scavenging techniques have been used to assess the antioxidant activity of the ligand and complexes, indicating good antioxidant activity. The Ni(II) complex was the most potent with the lowest IC50 values. The in vitro antibacterial activities have been explored by screening against bacteria (Bacillus subtilis) and bacteria (E. coli) exhibiting significant activity against the tested strains of bacteria with Zn(II) complex as most potent with the lowest MIC value against E. coli and B. subtilis) and highest zone of inhibition against E. coli and B. subtilis at 1000 μg/mL concentration). The antifungal activity of complexes against Aspergillus niger and Candida albicans indicate that the Co(II) complex is most active for C. albicans and Zn(II) complex for A. niger .

Bioremediation of Kalamkari Dye using Novel Bacterium Bacillus Inaquosorum Isolated from Textile Contaminated Waste Soil of Srikalahasti, A. P

Bioremediation of Kalamkari Dye using Novel Bacterium Bacillus Inaquosorum Isolated from Textile Contaminated Waste Soil of Srikalahasti, A. P

Chemical characterization, antimicrobial and mosquito larvicidal activities of the essential oil of Camellia pleurocarpa (Gagnep.) Sealy from Vietnam

Camellia pleurocarpa (Gagnep.) Sealy, a species of yellow camellia indigenous to Vietnam, was investigated for its essential oil properties in this study. Hydrodistillation of its leaves yielded a complex mixture rich in sesquiterpenes and diterpenes. Chemical analysis identified 50 constituents, with notable compounds including spathulenol (13.26%), phytol (9.94%), and α-selinene (5.34%). The essential oil exhibited significant antimicrobial activity against three Gram-positive bacteria Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus; one Gram-negative bacterium Pseudomonas aeruginosa; and one yeast Candida albicans, with minimum inhibitory concentration (MIC) values ranging from 16 to 32 μg/mL and half-maximal inhibitory concentration (IC50) values ranging from 7.26 to 16.23 μg/mL. Furthermore, it demonstrated larvicidal potential against Aedes aegypti and Culex quinquefasciatus mosquitoes, with LC50 values ranging from 13.49 to 28.95 μg/mL and LC90 values ranging from 28.29 to 53.24 μg/mL. These findings underscore the promising antimicrobial and mosquito larvicidal properties of C. pleurocarpa essential oil, suggesting its potential as a natural alternative in combating microbial infections and controlling mosquito-borne diseases. This study represents the first comprehensive report on the chemical compositions and bioactivities of C. pleurocarpa essential oil.

Utilizing pomegranate extracts for enhancing yogurt quality and preservation

As consumers become increasingly conscious of synthetic preservatives, the demand for natural antioxidant and antibacterial agents is rising. This study investigates the potential of pomegranate (Punica granatum) extracts to control yogurt spoilage. Methanolic and ethanolic extracts of pomegranate peel, seed, and leaf were analyzed for total phenolic content (TPC), antioxidant activity, and inhibitory effects on ‘yogurt starter strains’ and selected food-related bacteria (Bacillus cereus, Staphylococcus aureus, Staphylococcus sciuri, Escherichia coli, Salmonella enterica subsp. enterica serovar Typhi, and Shigella flexneri). Yogurt samples treated with pomegranate extracts were stored at 4 °C for 28 days. Sensory evaluation was performed on fresh yogurt samples. Physicochemical properties (pH, titratable acidity (TTA), and antioxidant activity) and microbiological changes (aerobic plate count (APC), coliform count, lactic acid bacteria (LAB) count, and total yeast and mold count (TYMC)) were examined weekly. Among the extracts tested, methanolic and ethanolic extracts of peel had the highest TPC (603 and 576.9 mg GAE/g) and the strongest antioxidant activity with the lowest IC50 (141.8 and 183.43 µg/mL). Overall, pomegranate peel, seed, and leaf extracts inhibited foodborne bacteria more effectively than probiotic strains, indicating significant antibacterial potential against spoilage microorganisms. Based on a minimum inhibitory concentration (MIC) test, ethanolic pomegranate extracts were incorporated into lab-made yogurt at 8 mg/mL. Throughout the storage period, all yogurt samples maintained a standard pH (≤ 4.6) and TTA (> 0.5 %). Yogurt fortified with pomegranate peel and leaf extracts exhibited greater antioxidant activity and a significantly lower aerobic plate count while retaining LAB probiotic levels (≥ 106 CFU/g), ensuring safety for consumption (TYMC ≤ 102 CFU/g) and acceptability in terms of five selected quality attributes. Consequently, pomegranate peel and leaf extracts present a promising natural alternative to potassium sorbate in yogurt preservation, maintaining probiotic properties without compromising quality.

Three-Year Monitoring of Microorganisms' Composition and Concentration in Atmospheric Aerosols of Novosibirsk City and Suburbs.

The atmospheric environment is formed under the influence of local and distant sources as a result of horizontal and vertical transport. In the present work, microbiological analysis of 604 samples of atmospheric aerosol collected in the period from September 2020 to September 2023 at four sites differing in anthropogenic load, located in Novosibirsk and the region, was carried out. Day and night aerosol samples were collected during 12 h every two weeks by filtration using Sartorius reinforced Teflon membranes, then sown on a set of nutrient media. The taxonomic affiliation of the isolated microbial isolates was determined based on phenotypic characteristics and analysis of 16S rRNA gene nucleotide sequences. Changes in the composition and concentration of culturable microorganisms depending on the season, time of day, and site of aerosol sampling were observed. In winter, lower fungi and bacteria of the genera Bacillus, Staphylococcus, Micrococcus dominated with an average concentration from zero to 12.5 CFU/m3 of aerosol. In the warm period, the concentration and diversity of cocci, spore-forming and non-spore-forming bacteria, actinomycetes, and fungi (up to 1970 CFU/m3), among which pathogenic microorganisms were found, increased sharply in aerosols. The use of 16S metabarcoding techniques has greatly expanded the range of aerosols' microbial diversity detectable.

Responses of Intestinal Antioxidant Capacity, Morphology, Barrier Function, Immunity, and Microbial Diversity to Chlorogenic Acid in Late-Peak Laying Hens.

This study examined the influence of chlorogenic acid (CGA) on gut antioxidant status, morphology, barrier function, immunity, and cecal microbiota in late-peak laying hens. A total of 240 Hy-Line Brown hens, aged 43 weeks, were randomly assigned to four groups, the basal diet +0, 400, 600, and 800 mg/kg CGA, for 12 weeks. The results revealed that CGA significantly reduced ileal H2O2 and malondialdehyde levels; increased duodenal height, ileal villus height, and villus height-to-crypt depth ratio; while decreasing jejunal crypt depth. The 600 and 800 mg/kg CGA significantly upregulated the duodenal, jejunal, and ileal ZO-1 and occludin gene expression; increased IgG levels in serum and ileum; and upregulated ileal IgA gene expression. The 600 mg/kg CGA significantly upregulated CD3D and CD4 gene expression, while downregulating IL-1β gene expression in duodenum, jejunum, and ileum. Moreover, CGA changed the gut microbiota structure. The SCFA-producing bacteria unclassified_f__Peptostreptococcaceae, unclassified_f_Oscillospiraceae, Pseudoflavonifractor, Lachnospiraceae_FCS020_group, Oscillospira, Elusimicrobium, Eubacterium_ventriosum_group, Intestinimonas, and norank_f_Coriobacteriales_Incertae_Sedis were significantly enriched in the 400, 600, and/or 800 mg/kg CGA groups. The bacteria Lactobacillus, Bacillus, and Akkermansia were significantly enriched in the 600 mg/kg CGA group. Conclusively, dietary CGA (600-800 mg/kg) improved intestinal antioxidant status, morphology, barrier and immune function, and beneficial microbiota growth in late-peak laying hens.

Analisis Kestabilan Model Penyebaran Penyakit Antraks pada Populasi Ternak dengan Transmisi Tak Langsung dan Penggunaan Desinfektan

Anthrax is an infectious disease caused by the bacterium Bacillus anthracis. This disease causes a fairly high mortality rate in livestock populations that can threaten food security in a region. Therefore, it is necessary to prevent and control its spread. This study aims to examine the model of the spread of anthrax disease in a livestock population by considering indirect transmission and the use of disinfectants. The constructed model is expressed as a system of ordinary differential equations. Dynamical analysis is carried out to identify the stability properties of the disease-free equilibrium point. The results of the dynamical analysis show that the disease-free equilibrium point is conditionally stable, namely when the basic reproduction number is less than one. In addition, the results of numerical experiments show that the use of disinfectants has a significant effect on the dynamics of the spread of anthrax disease, namely the higher the rate of bacterial death due to disinfectants, the fewer cases of anthrax. This study shows that the use of disinfectants can be an effective strategy to control the spread of anthrax disease in livestock populations.