Bacterium Bacillus Research Articles

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 .

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.

Green synthesis of silver/silver oxide nanostructures using the Malva sylvestris extract prior to simultaneous distillation extraction: synthesis, phytochemical and biological analysis.

Nanotechnology and nanoscience are due to their numerous uses in medicine, engineering, and water pollution sensors and their expanding research fields. In this study, the essential oil, methanolic extract, and biosynthesized silver/silver oxide nanostructures (Ag/AgO NSs) using the aqueous extract of the plant were prepared. The phytochemical compounds of the extract and essential oil were analyzed using gas chromatography/mass spectrometry (GC/MS), respectively. The GC/MS technique identified 34 compounds in the essential oil of the plant with the major constituents including oleic acid (18.5%), palmitic acid (11.08%), phytone (6.64%), p-vinylguaiacol (6.4%), and phytol (4.23%). After the phytochemical identification, the total flavonoid and polyphenol contents of the extract was determined, too. Prodelphinidin B3 compound in the Malva sylvestris extract was analyzed and detected by high-performance liquid chromatography/ultraviolet detector (HPLC-UV), at a retention time of around 10 min. In addition, M. sylvestris extract was used for green synthesis of Ag/AgO NSs. The as-prepared NPs were characterized using X-ray diffraction (XRD), UV-visible absorption spectroscopy, scanning electron microscope equipped with energy-dispersive X-ray spectroscopy (SEM/EDS), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), and Fourier transform infrared (FT-IR) analyses. Surface plasmon resonance (SPR) absorption at λmax 320 nm in the UV-vis spectra confirms the formation of Ag/AgO NSs. The crystalline structure of Ag/AgO NSs was confirmed by XRD analysis.The nanoparticles were found to have a small size, measuring 64.16 nm, 44.33 nm, and 50 nm using the Williamson-Hall, Scherrer, and SEM/EDS methods, respectively. Besides, that spherical shape of Ag NPs with good size distribution was observed in the SEM/EDS analysis. The small size, around 50 nm, and spherical shape of Ag/AgO NSs with good size distribution were observed in the SEM/EDS analysis. Besides, the antibacterial activity of the extract was evaluated against three pathogenic bacteria, by disk diffusion method. Significant antibacterial activity was observed for the prepared extracts of M. sylvestris against the bacteria (Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa), and the results were compared with the known antibiotics such as amoxicillin, cephalexin, erythromycin, and fluconazole.

A review of the potential impacts of coastal mosquito control programs on Australian Stingless Bees (Apidae, Meliponini)-likely exposure pathways and lessons learned from studies on honey bees.

The impact of the programmatic use of larvicides for mosquito control on native stingless bees (e.g., Apidae, Meliponini) is a growing concern in Australia due to heightened conservation awareness and the growth of hobbyist stingless bee keeping. In Australia, the two most widely used mosquito larvicides are the bacterium Bacillus thuringiensis var. israelensis (Bti) and the insect hormone mimic methoprene (as S-methoprene). Each has a unique mode of action that could present a risk to stingless bees and other pollinators. Herein, we review the potential impacts of these larvicides on native Australian bees and conclude that their influence is mitigated by their low recommended field rates, poor environmental persistence, and the seasonal and intermittent nature of mosquito control applications. Moreover, evidence suggests that stingless bees may display a high physiological tolerance to Bti similar to that observed in honey bees (Apis mellifera), whose interactions with B. thuringiensis-based biopesticides are widely reported. In summary, neither Bti or methoprene is likely to pose a significant risk to the health of stingless bees or their nests. However, current knowledge is limited by regulatory testing requirements that only require the use of honey bees as toxicological models. To bridge this gap, we suggest that regulatory testing is expanded to include stingless bees and other nontarget insects. This is imperative for improving our understanding of the potential risks that these and other pesticides may pose to native pollinator conservation.

Combination of the degrading bacterium Bacillus cereus MZ-1 and corn straw biochar enhanced the removal of imazethapyr from water solutions

Long residual herbicide imazethapyr has caused a serious threat to subsequent sensitive crop plants and ecological security. Efficient immobilized microorganism technology offers a sustainable solution for remediating pesticides contamination. In this study, three corn straw biochars produced at 300℃, 500℃, and 700℃ were used as carriers to immobilize the imazethapyr degrading strain Bacillus cereus MZ-1, aiming to efficiently remove imazethapyr from the water environment. Response surface methodology was employed to optimize the best immobilization conditions based on the efficiency of imazethapyr removal. The results indicate that the biochar produced at 500 ℃ was the most effective carrier for immobilization, despite having a lower imazethapyr removal capacity compared to the biochar produced at 700 ℃. Additionally, the optimal strain addition amount was a suspension of strain MZ-1 (OD600=1) in a 3.5-fold biochar solution, and the best immobilized time was 18 h. The prepared immobilized MZ-1 achieved a maximum imazethapyr removal efficiency of 79.85 %. Moreover, the immobilized MZ-1 demonstrated enhanced detoxification efficacy against imazethapyr-induced harm in sensitive oilseed rape crops, surpassing the effects of using MZ-1 or biochar alone. Results of this work suggests biochar immobilized degradation strain MZ-1 is a highly effective in-situ remediation strategy for bioremediation of imazethapyr contamination.

Complex sporulation-specific expression of transcription termination factor Rho highlights its involvement in Bacillus subtilis cell differentiation

Termination factor Rho, responsible for the main factor-dependent pathway of transcription termination and the major inhibitor of antisense transcription, is an emerging regulator of various physiological processes in microorganisms. In Gram-positive bacterium Bacillus subtilis, Rho is involved in the control of cell adaptation to starvation and, in particular, in the control of sporulation, a complex differentiation program leading to formation of a highly resistant dormant spore. While the initiation of sporulation requires a decrease in Rho protein levels during the transition to stationary phase, the mechanisms regulating the expression of rho gene throughout the cell cycle remain largely unknown. Here we show that a drop in the activity of the vegetative SigA-dependent rho promoter causes the inhibition of rho expression in stationary phase. However, after the initiation of sporulation, rho gene is specifically reactivated in two compartments of the sporulating cell using distinct mechanisms. In the mother cell, rho expression occurs by read-through transcription initiated at the SigH-dependent promoter of the distal spo0F gene. In the forespore, rho gene is transcribed from the intrinsic promoter recognized by the alternative sigma factor SigF. These regulatory elements ensure the activity of Rho during sporulation, which appears important for the proper formation of spores. We provide experimental evidence that disruption of the spatiotemporal expression of rho during sporulation affects the resistance properties of spores, their morphology, and the ability to return to vegetative growth under favorable growth conditions.

Effect of Dietary Astragalus polysaccharides (APS) on the Growth Performance, Antioxidant Responses, Immunological Parameters, and Intestinal Microbiota of Coral Trout (Plectropomus leopardus)

The potential effects of Astragalus polysaccharides (APS) were evaluated in coral trout (Plectropomus leopardus). Five APS levels (0%, 0.05%, 0.10%, 0.15%, and 0.20%) were added to the diet of coral trout, and a 56-day growth trial (initial weight 18.62 ± 0.05 g) was conducted. Dietary APS enhanced growth performance, with the highest improvement observed in fish fed the 0.15% APS diet. This concentration also enhanced the antioxidant capacity and immunomodulation of the fish by regulating the expression of genes associated with antioxidant enzymes and immune responses. Intestinal microbiota analysis revealed that APS supplementation significantly increased the Chao1 index and relative abundance of beneficial bacteria (Firmicutes and Bacillus). A high level of APS (0.20%) did not provide additional benefits for growth and health compared to a moderate level (0.15%). These findings indicate that an optimal APS dose promotes growth, enhances antioxidant activity, supports immune function, and improves intestinal microbiota in coral trout. Based on a cubic regression analysis of the specific growth rate, the optimal APS level for the maximal growth of coral trout was determined to be 0.1455%.

Introduction of a Sodium-Binding Motif into Subunits <i>a</i> and <i>c</i> of <i>Bacillus</i> sp. PS3 Proton F-ATPase Does Not Result in Sodium Specificity of the Enzyme

In bacteria F-type ATPase (F-ATPase) plays a key role in bioenergetics and couples ATP synthesis/hydrolysis with the transport of ions (H+ or Na+) across the membrane. The ion specificity of the enzyme is determined by the amino acid sequence of subunits c and а. Here, we introduced several mutations (7 in subunit c and 6 in subunit a) into F-ATPase of thermophilic bacterium Bacillus sp. PS3 in order to change the ion specificity of the enzyme from proton to sodium. The mutations did not affect the ATPase activity of the enzyme, but led to loss of proton conductivity and impaired the binding of subunit a to the c-subunit oligomer, rather than changed the ion specificity.

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

Green synthesized CeO2 nanoparticles-based chitosan/PVA composite films: Enhanced antimicrobial activities and mechanical properties for edible berry tomato preservation.

The current study is intended to enhance unique bioactive and eco-friendly composite films following a simple solvent-casting approach by incorporating cerium oxide nanoparticles (CeO2 NPs) with a chitosan (CS)/polyvinyl alcohol (PVA) matrix. Antimicrobial activity, preservation impact, mechanisms for the edible berry tomatoes and physicochemical properties of the produced films were tested. FTIR, SEM-EDX, XRD, UV–vis spectroscopy and contact angle were used to characterize the films. Incorporated (3.0 wt%) CeO2 NPs practically developed composite film's thermal stability, structural, mechanical, bioactive, antioxidant, barrier and wettability properties. The tomatoes' look, weight loss and stiffness were better preserved after 25 days of storage at room temperature (25 ± 5 °C) when 3.0 wt% CeO2 NPs films were used instead of the original CS/PVA film. CS and CeO2 NPs have unique physiochemical and antibacterial properties. Food packaging extensively investigates the modified films as antimicrobials and preservatives to increase the shelf life of packaged foods, owing to their ability to inhibit gram-positive bacteria (Bacillus cereus and Staphylococcus aureus), gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa), and filamentous fungi (Bipolaris sorokiniana, Fusarium op., and Alternaria sp.). Our findings indicated that the CeO2/CS/PVA composite films could be used as effective wrapping materials for food preservation.

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.