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Bacterial blight in pomegranate, caused by Xanthomonas citri pv. punicae (Xcp), is one of the most devastating diseases, leading to substantial economic losses in pomegranate production. Methods for blight management in pomegranate production are scarce and not well established. To date, the major control strategy is targeting the pathogen with antibiotics and copper-based compounds. However, excessive use of antibiotics has resulted in the development of antibiotic resistance in the field population of Xcp. Hence, as a means of eco-friendly and sustainable management of bacterial blight, the use of native endophytes was investigated under field conditions in the current study. Endophytic bacteria were isolated from micro-propagated nodal explants of pomegranate and were identified as Bacillus haynesii , B. tequilensis , and B. subtilis. They were found to produce volatiles that inhibited Xcp growth during in vitro antibiosis assay. GC–MS-based volatile profiling revealed the presence of several bioactive compounds with reported antimicrobial activities. These endophytes (CFU of 108/mL) were then spray-inoculated on leaves of 6-month-old pomegranate plants in the polyhouse. They were found to induce ROS-scavenging enzymes such as catalase and peroxidase. This alteration was a manifestation of host tissue colonization by the endophytes as ROS scavenging is one of the mechanisms by which endophytes colonize the host plants. Furthermore, two-season field trials with endophytes for blight control resulted in a reduction of disease index by 47–68%, which was considerably higher than the reduction due to the chemical immune modulator (2-bromo-2-nitro-1, 3-propanediol) currently being recommended for blight control. In addition, these endophytes also exhibited reduced sensitivity to this immune modulator; thus, the current study advocates the use of B. haynesii , B. subtilis , and B. tequilensis as biocontrol agents for bacterial blight of pomegranate either alone or as a part of integrated disease management. [ABSTRACT FROM AUTHOR]

Spore‐forming organisms are an integral component of the rhizosphere, providing plants with significant advantages. Previous studies determined the antimicrobial activity of the olive sporobiota, identifying five candidates of particular relevance, belonging to the Bacillus subtilis, Peribacillus simplex and Bacillus cereus clade. This study aimed to determine their biotechnological properties, safety aspects, spore structure and resistance, and interaction with the environment through a combined microbiological and genomic approach. We report on the ability of these strains to produce hydrolytic and surface‐active enzymes and provide evidence for differences in population behaviour through the formation of strong sessile or floating biofilms. Electron microscopic analysis revealed for the first time the presence of an exosporium layer in olive sporobiota isolates belonging to the P. simplex and B. cereus clade, including numerous pili‐like structures on the latter. Spores showed significant differences in their resistance to wet heat, oxidising agents, and UV exposure. Whole genome sequencing of isolate Peribacillus frigoritolerans yielded information on its antimicrobial compound biosynthesis and environmental safety. Overall, our findings provide insights into the phenotypic, morphological and genetic variations of spore‐formers from Spanish olive groves, which can be useful for the development of bioactive compounds in sustainable agriculture. [ABSTRACT FROM AUTHOR]

The present study tested the symbiotic effects of dietary multi-strain Bacillus probiotics (MSB) (Bacillus licheniformis, B. pumilus, and B. subtilis) in Nile tilapia (Oreochromis niloticus) exposed to Aspergillus flavus infection. Furthermore, this study investigated water quality, growth performance, blood metabolites, histological morphology, immune regulatory genes, and resistance to A. flavus infection. For 70 days, fish (n = 240) were divided into four groups in triplicate: T0 (control group; MSB0), T1 (1 g/kg, MSB1), T2 (2 g/kg, MSB2), and T3 (3 g/kg, MSB3). The immune response was then assessed by challenging all fish groups with the A. flavus pathogen. The results showed that the rearing water quality, fish growth, and blood parameters, as well as total proteins, albumin, globulins, and amylase activity were significantly (P < 0.05) increased in all MSB-treated groups with the best results in MSB2 and MSB3 groups. Meanwhile, the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, and glucose levels were significantly (P < 0.05) modulated, particularly at higher concentrations of the probiotic mixture (MSB3 group). Fish fed with various levels of MSB showed a maintained histological structure of the hepatopancreas, intestine, and spleen tissues. The mRNA expression of growth hormone (GH), insulin-like growth factor-1 (IGF-1), insulin-like growth factor receptor-1 (IGF-1R), and interleukin-8 (IL-8) were increased in a dose-dependent manner due to MSB dietary inclusion (P < 0.05). Conversely, the mRNA expression of interleukin-1β (IL-1β) gene was significantly decreased in MSB groups compared to untreated group (P < 0.05). Surprisingly, supplemented groups in Bacillus spp. probiotics exhibited significant modulations in all computed parameters. MSB supplementation improved the pathogenic tolerance of tilapia after change with A. flavus. The integration of growth performance, biochemical, and transcriptomic results confirms that the dietary intervention of multi-strain Bacillus spp. is symbiotic and enhances the benefits for the maintenance of O. niloticus' health, growth, and digestion. This is achieved by supporting growth genes, reducing inflammatory genes, and enhancing immune-antioxidant resistance to combat A. flavus infection. [ABSTRACT FROM AUTHOR]

Bacillus pseudomycoides , Paenibacillus polymyxa , and B. velezensis are potent bacterial endophytes, which typically exhibit host-specific interactions. However, comparative studies of these endophytes in vitro and in planta in non-host crops are lacking. Therefore, in this study, we evaluated the potential of endophytes B. pseudomycoides strain HP3d, P. polymyxa strain PGSS1, B. velezensis strain A6, and P42, isolated from various crop ecosystems in promoting plant growth and inducing systemic resistance against early blight disease in tomato. In vitro , endophytes exhibited 44.44–55.56% and 37.50–87.50% inhibition of Alternaria solani in dual culture and volatilome bioassay, respectively. In the glasshouse, individual and combined applications via seed treatment (ST), seedling dip (SD), and foliar spray (FS) significantly enhanced shoot growth (23.63–57.61%), root growth (43.27–118.23%), number of leaves (77.52–93.58%), number of shoots (33.42–45.28%) and root dry matter (42.17–43.86%), reducing early blight (PDI) by 70.95–76.12% compared to uninoculated control. Enzymatic activities, including such as polyphenol oxidase (30–40 fold), peroxidase (65.00–75.00 fold), superoxide dismutase (34.20–37.20 fold) and phenylalanine ammonia-lyase (44.44–45.56 fold) were elevated post-inoculation in endophytes treated tomato plants challenged with A. solani compared to control treated only with A. solani and declined after the fifth day. The total chlorophyll content declined from the 0th to the 10th day, but endophyte treated plants exhibited lesser reductions (2.03–2.09) than uninoculated control. Field trials confirmed the glasshouse findings, showing reduced early blight and improved growth parameters in tomato where the ST + SD + FS combination emerged as the most effective treatment for all endophytes showing 1.06–1.88 fold increase in fruit yield per plant and 28.92–32.52% decrease in PDI compared to untreated control. Thus, the study highlights the broad-spectrum potential of these strains in promoting plant growth and controlling early blight in tomato, demonstrating non-host specificity. These endophytes offer eco-friendly alternatives to chemical pesticides, supporting sustainable agriculture. Their success in field trials suggests the potential for commercialization and large-scale use across diverse crops and pave the way for further interdisciplinary research to optimize their application in integrated pest management strategies. [ABSTRACT FROM AUTHOR]

Bacillus spp. are foodborne pathogens important in food contamination, especially in dried milk products. They are associated with foodborne outbreaks, spoilage of dairy products (sweet curdling and bitterness), and bovine mastitis. This study investigated the contamination rate of Bacillus spp. in a total of 105 samples of the dried milk products kishk, Cerelac and whole milk powder, marketed in Assiut city, Upper Egypt. The identification of the Bacillus spp. strains was completed using conven-tional biochemical methods and PCR protocols for the confirmation of isolates. Bacillus spp. were isolated from 57 out of 105 (54%) [95% CI: 44.664.0%] of the examined samples at levels of up to 7.7 log10 cfu/g. The prevalence of Bacillus spp. was significantly (P

Sclerotinia minor (S. minor) Jagger is a phytopathogenic fungus that causes lettuce drop, a serious problem in lettuce (Lactuca sativa L.) production. The control of this pathogen is challenging because of the resistance of sclerotia, which can survive in the soil under favorable conditions. In Bulgaria, the management of lettuce drop relies primarily on the strategic application of synthetic fungicides. To find alternative methods for disease management, four bacterial isolates were screened for antagonism against S. minor. This study reports the in vitro evaluation of the antifungal activity of Bacillus subtilis, Priestia megaterium, Bacillus safensis, and Bacillus mojavensis against S. minor. The molecular identification of the isolates involved in the activity was examined through 16s rRNA sequencing. Isolated bacterial strains produced indole-3-acetic acid (IAA) in a medium supplemented with 0.1% L-tryptophan. The ability of these strains to increase the mobility of phosphorus and zinc was elucidated. The production of siderophores was confirmed on CAS (Chrom azurol S) medium. The inhibitory action of the bacterial growth broth filtrates against S. minor was demonstrated, indicating the nature of the molecules involved. The evaluation of antifungal activity was carried out in vitro and in pot experiments. This study determined the effect of growth-promoting rhizobacteria on the development of lettuce. This research focuses mainly on the development of biocontrol strategies for the management of lettuce drop in greenhouses.

For years, the Bacillus genus has encompassed a heterogeneous group of individuals whose main common trait was their ability to sporulate in the presence of oxygen. This criterion has been revised, resulting in the reclassification of several species into new genera and to a redefinition of the characteristics of the members of this taxon. Currently, the species of the genus are grouped into the Subtilis clade and the Cereus clade. The former, called Bacillus sensu stricto, initially composed of B. subtilis, B. licheniformis, B. pumilus, and B. amyloliquefaciens, has subsequently incorporated new species related to these. The Cereus clade, Bacillus cereus sensu lato, consists of pathogenic species (B. anthracis, B. cereus, and B. thuringiensis) as well as others of significance in agriculture and industry. Furthermore, identifying these individuals remains complex, requiring alternatives to 16S rRNA sequencing. The ability to form spores resistant to stressful conditions provides a significant advantage over other genera, with observable differences in sporulation rates and spore structure among different species. Additionally, Bacillus spp. are known for their capacity to produce antimicrobial substances, lytic enzymes, and volatile organic compounds, each with diverse applications. Some species are even used as probiotics. This review delves into aspects related to the taxonomy and identification of microorganisms belonging to the genus Bacillus, which often present challenges. The aim is to provide a comprehensive overview of the topic. In addition, it highlights the characteristics and applications of the genus, emphasizing its importance in biotechnology and microbiology.

Grey mold, caused by the fungus Botrytis cinerea, is one of the most prevalent diseases affecting strawberry plants (Fragaria ananassa). The objective of this study was to assess the antagonistic effect of 5 bacterial strains belonging to the genus Bacillus spp. (BA1, BF2, BB3, BI3, and BO4) against B. cinerea, tested both in vitro and in vivo on strawberry fruits. The strains exhibited antifungal activity against B. cinerea under in vitro conditions, both through direct confrontations and antibiosis tests, as well as through the effect of organic compounds. Strain BO4 could inhibit mycelial growth by 62.92% through direct confrontation and 64.58% through the secretion of volatile organic compounds. Additionally, the strain BF2 demonstrated a high antibiosis effect (74.64%) compared to the control at a concentration of 25%. Treating fruits with the bacterial suspension and culture filtrate of the 5 studied strains controlled grey mold growth in vivo, as indicated by low severity indices in strawberries treated with strains BI3, BF2, and BA1, marked by percentages of 24.44%, 24.44%, and 37.78%, respectively, for preventive treatment. The difference in the effectiveness of various strains depended on the treatment mode; preventive treatment proved to be more effective compared to curative treatment.

Background: The phenomenon of microbiologically induced calcite precipitation (MICP) is a part of the chemical process called biomineralization. Microorganisms form inorganic solids like calcite by such process. Bacillus spp. are common soil bacteria that may induce calcite precipitation. The microbial sealant properties of CaCO3 improve mortar and concrete's compressive strength. Methods: This study examined the impact of locally isolated Calcite-Producing bacteria on mortar characteristics. Eight isolates of Bacillus spp. have been prepared in suspensions adjusted to absorbance of 1 at 600 nm, that contain 2% urea and 25 mmoll-1 calcium chloride, and applied to prepare mortar cubes. The ratio of cement: sand: water mix was 1:3:0.5. Control cubes were prepared using the same mix ratio and containing water instead of bacterial suspension. Compressive strengths for all cubes on days 7 and 28 were measured. A durability tests and water absorption test for the cubes were performed. Results: Bacterial mortar cubes showed a compressive strength about 39 to 81% and 9.6 to 60.2% higher than the control on the 7th day and 28th day, respectively. Bacterial mortar cubes resist H2SO4 attack at pH = 2, while control cubes couldn't resist at pH = 6. After treatment with 5% MgSO4, all bacterial cubes showed higher compressive strengths. Water absorption of bacterial cubes ranged from 2.4-4.8%, while the control cubes absorbed water with a percentage of 7.2%. Conclusion: These species are promising contenders for MICP involved investments, and can be used in a many of construction applications. [ABSTRACT FROM AUTHOR]

Aims: Silver nanoparticles were synthesized using Syzygium polyanthum plant extract (SP-AgNPs). The S. polyanthum leaf extract acts as a reducing and capping agent in the synthesis of silver nanoparticles. This study was aimed to investigate the sporicidal activity of S. polyanthum-mediated silver nanoparticles (SP-AgNPs) against spores of Bacillus cereus ATCC33019, B. megaterium ATCC14581, B. pumilus ATCC14884 and B. subtilis ATCC6633. Methodology and results: The sporicidal activity of the SP-AgNPs was evaluated by exposing Bacillus spp. spores to it and formaldehyde, a commercial sporicidal agent and measuring and comparing their viability. The results demonstrated that the SP-AgNPs had excellent sporicidal activity against all tested species, with a remarkable reduction in the spore count. The study also revealed that the sporicidal activity of the SP-AgNPs was time-dependent and comparable to the positive control used in the study, suggesting that they could be a potential alternative to natural sporicidal agents. Conclusion, significance and impact of study: Research findings suggest that the potential of SP-AgNPs, making them a promising candidate for use in sporicidal applications. These findings suggest that using SP-AgNPs as a sporicidal agent could be a new approach to eliminating Bacillus spp. spores in food and other industries where Bacillus spp. spores pose a significant risk. Further research is required. [ABSTRACT FROM AUTHOR]

To explore the effects of two strains of Bacillus spp. combined with organic fertilizer on the growth and fruit of sunshine rose, and to further expand the application range of microbial fertilizer on grapes. In November 2020, two strains of Bacillus velezensis YH-18 and B. velezensis YH-20 were applied to the sunshine rose grapes planted in Fengxian District of Shanghai. Two kinds of microbial liquid inoculants were applied to the grape planting soil, diluted and mixed according to the ratio of bacterial liquid : water = 1 : 2, and then poured into the pesticide applicator. The bacterial liquid was directly sprayed on the applied organic fertilizer in the garden by spraying, and the soil was covered in time after application. In March 2021, the in situ reapplication was carried out.30 days after the first application, the chlorophyll content of grape leaves in the YH-18 and YH-20 treatment groups increased by 10.12% and 3.26% compared with the control; the leaf thickness increased by 22.16% and 10.80% compared with the control; the leaf area increased by 23.92% and 19.87% compared with the control. After two times of application, the ear weight ratio of grapes in the YH-18 and YH-20 treatment groups increased by 19.55% and 16.19% compared with the control; the longitudinal diameter of single fruit increased by 3.15% and 3.76% compared with the control; the fruit shape index was improved. The soluble solids content of grapes in the YH-18 and YH-20 treatment groups increased by 22.08% and 13.58% compared with the control; the titratable acid content of grapes in the YH-18 treatment group increased by 21.05% compared with the control;the water content of grapes decreased by 2.18% and 1.96% compared with the control;the hardness of grapes in the YH-18 treatment group increased by 20.9% compared with the control. The application of YH-18 and YH-20 microbial inoculants on the basis of organic fertilizer in the garden significantly improved the growth of grapes and improved the quality of fruits, which is suitable for widespread promotion in grape plantations. [ABSTRACT FROM AUTHOR]

The characterization of surface microbiota living in biofilms within livestock buildings has been relatively unexplored, despite its potential impact on animal health. To enhance our understanding of these microbial communities, we characterized 11 spore-forming strains isolated from two commercial broiler chicken farms. Sequencing of the strains revealed them to belong to three species Bacillus velezensis, Bacillus subtilis, and Bacillus licheniformis. Genomic analysis revealed the presence of antimicrobial resistance genes and genes associated with antimicrobial secretion specific to each species. We conducted a comprehensive characterization of the biofilm formed by these strains under various conditions, and we revealed significant structural heterogeneity across the different strains. A macro-colony interaction model was employed to assess the compatibility of these strains to coexist in mixed biofilms. We identified highly competitive B. velezensis strains, which cannot coexist with other Bacillus spp. Using confocal laser scanning microscopy along with a specific dye for extracellular DNA, we uncovered the importance of extracellular DNA for the formation of B. licheniformis biofilms. Altogether, the results highlight the heterogeneity in both genome and biofilm structure among Bacillus spp. isolated from biofilms present within livestock buildings. [ABSTRACT FROM AUTHOR]

The use of microbial seed priming may be a promising tool to improve the first stages of seed germination of several herbaceous species. In tomatoes (Solanum lycopersicum L.), enhanced germination and vigor, and biotic and abiotic stress control, with a reduction in chemicals, have been reported. In this study, seeds from two Italian tomato varieties (Canestrino di Lucca and Pisanello) were primed with seven different strains of plant growth-promoting rhizobacteria (PGPB) belonging to Azospirillum baldaniorum, A. brasilense, Methylobacterium symbioticum, Bacillus amyloliquefaciens, B. licheniformis, and B. subtilis. They were selected for their ability to produce auxin. The germination test was carried out on treated seeds and the germination percentage was calculated. The obtained seedlings were transplanted and kept in greenhouse conditions. After 60 d, fresh and dry weight, root number, and length of plantlets were recorded. A general and significant improvement in the growth parameters was observed in the treated plants. All microbial strains proved to be indolacetic acid (IAA) producers using the Salkowsky method. A positive relationship between root number and length, and amount of IAA was found. The overall results suggest that the microbial priming of tomato seed could be useful for advancing organic farming, sustainable agriculture, and environmental protection. [ABSTRACT FROM AUTHOR]

For years, the Bacillus genus has encompassed a heterogeneous group of individuals whose main common trait was their ability to sporulate in the presence of oxygen. This criterion has been revised, resulting in the reclassification of several species into new genera and to a redefinition of the characteristics of the members of this taxon. Currently, the species of the genus are grouped into the Subtilis clade and the Cereus clade. The former, called Bacillus sensu stricto, initially composed of B. subtilis, B. licheniformis, B. pumilus, and B. amyloliquefaciens, has subsequently incorporated new species related to these. The Cereus clade, Bacillus cereus sensu lato, consists of pathogenic species (B. anthracis, B. cereus, and B. thuringiensis) as well as others of significance in agriculture and industry. Furthermore, identifying these individuals remains complex, requiring alternatives to 16S rRNA sequencing. The ability to form spores resistant to stressful conditions provides a significant advantage over other genera, with observable differences in sporulation rates and spore structure among different species. Additionally, Bacillus spp. are known for their capacity to produce antimicrobial substances, lytic enzymes, and volatile organic compounds, each with diverse applications. Some species are even used as probiotics. This review delves into aspects related to the taxonomy and identification of microorganisms belonging to the genus Bacillus, which often present challenges. The aim is to provide a comprehensive overview of the topic. In addition, it highlights the characteristics and applications of the genus, emphasizing its importance in biotechnology and microbiology. [ABSTRACT FROM AUTHOR]

Sclerotinia minor (S. minor) Jagger is a phytopathogenic fungus that causes lettuce drop, a serious problem in lettuce (Lactuca sativa L.) production. The control of this pathogen is challenging because of the resistance of sclerotia, which can survive in the soil under favorable conditions. In Bulgaria, the management of lettuce drop relies primarily on the strategic application of synthetic fungicides. To find alternative methods for disease management, four bacterial isolates were screened for antagonism against S. minor. This study reports the in vitro evaluation of the antifungal activity of Bacillus subtilis, Priestia megaterium, Bacillus safensis, and Bacillus mojavensis against S. minor. The molecular identification of the isolates involved in the activity was examined through 16s rRNA sequencing. Isolated bacterial strains produced indole-3-acetic acid (IAA) in a medium supplemented with 0.1% L-tryptophan. The ability of these strains to increase the mobility of phosphorus and zinc was elucidated. The production of siderophores was confirmed on CAS (Chrom azurol S) medium. The inhibitory action of the bacterial growth broth filtrates against S. minor was demonstrated, indicating the nature of the molecules involved. The evaluation of antifungal activity was carried out in vitro and in pot experiments. This study determined the effect of growth-promoting rhizobacteria on the development of lettuce. This research focuses mainly on the development of biocontrol strategies for the management of lettuce drop in greenhouses. [ABSTRACT FROM AUTHOR]

Seven auxin-producing endophytic bacterial strains (Azospirillum spp., Methylobacterium symbioticum, Bacillus spp.), and two different combinations of these strains were used to verify their influence on tomato during germination and development in hydroponic conditions where, as a novelty for Canestrino di Lucca cultivar, endophytic bacteria were inoculated. To emphasize the presence of bacterial auxins in roots and stems of seedlings, both in situ staining qualitative assessment and quantitative analysis were carried out. Moreover, hypogeal and epigeal growth of the plantlets were measured, and correlation analyses were conducted to examine the relationship between the amount of indolacetic acid (IAA) produced by the bacterial strains and root and stem parameters. Plantlets treated with microbial inoculants showed a significant increase in the survival rate compared to the control treatment. The best results as IAA producers were from Azospirillum baldaniorum Sp245 and A. brasilense Cd, which also induced significant root growth. On the other hand, Bacillus amyloliquefaciens and B. licheniformis induced the best rates in stem growth. These findings highlight the potential for using endophytic bacterial strains in a hydroponic co-cultivation system that enables inoculating plantlets, at an early stage of growth (5 days old). [ABSTRACT FROM AUTHOR]

Bacillus spp. are foodborne pathogens important in food contamination, especially in dried milk products. They are associated with foodborne outbreaks, spoilage of dairy products (sweet curdling and bitterness), and bovine mastitis. This study investigated the contamination rate of Bacillus spp. in a total of 105 samples of the dried milk products kishk, Cerelac and whole milk powder, marketed in Assiut city, Upper Egypt. The identification of the Bacillus spp. strains was completed using conventional biochemical methods and PCR protocols for the confirmation of isolates. Bacillus spp. were isolated from 57 out of 105 (54%) [95% CI: 44.6-64.0%] of the examined samples at levels of up to 7.7 log10 cfu/g. The prevalence of Bacillus spp. was significantly (P<0.05) higher in kishk (74%) than in the other food categories with a mean count of 4.04±0.49 log10 cfu/g. Regarding the species of Bacillus detected, 39.05% of the examined samples contained B. cereus, 8.57% contained B. subtilis, 2.86%: B. pumilus, another 2.86%: B. megatrium and 0.95%: B. licheniformis. B. cereus was isolated from 18 (51.43%) of the kishk samples, 9 (25.71%) of the Cerelac samples and 14 (40%) of the whole milk powder samples. Out of the 41 B. cereus strains previously identified by biochemical tests, 19 (46.34%) isolates were also confirmed using PCR (61.11%, 42.86% and 22.22% for kishk, whole milk powder and Cerelac, respectively). In conclusion, incorporating preventive measures to reduce bacterial contamination in the Egyptian dairy environment are warranted in order to avoid the contamination of milk products with these life-threatening pathogens. [ABSTRACT FROM AUTHOR]

The purpose of this study was to isolate, identify, and evaluate the antibacterial and probiotic potential of bacteria from honeydew honey collected in Poland. Isolates (189 colonies from 10 honey samples) were evaluated for their antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Yersinia enterocolitica, and then identified by MALDI-TOF-MS. The isolates with the greatest antimicrobial properties were screened for their probiotic potential. The total number of bacteria isolated from honey did not exceed the value of 2.5 × 102 CFU/mL. The Bacillus pumilus/altitudinis, B. licheniformis, and Bacillus cereus groups were the dominant identified bacteria. Almost 16% of the isolates expressed antibacterial potential against three pathogenic bacteria, over 20% against two, while almost 34% of the isolates did not inhibit any. The survival rate of the isolates under gastrointestinal tract conditions was higher after 4 h of exposure to bile salts (>60% survival rate for 66.66% of the isolates), while at pH 2.0, it was lower (>50% survival rate for 44% of the isolates). The most resistant isolate B. pumilus/altitudinis survived at a rate of 77% at low pH and 108% with bile salts. These results confirmed that honeydew honey is a promising reservoir of bacteria that produces metabolites with antimicrobial and probiotic potential. [ABSTRACT FROM AUTHOR]

γ‐Polyglutamic acid (γ‐PGA) microgel, produced by Bacillus spp., represents a promising biomaterial with diverse industrial applications due to its biodegradability, biocompatibility, and nontoxic nature. This review explores the current methodologies in the industrial production of γ‐PGA microgel, emphasizing the optimization of fermentation conditions, genetic engineering of Bacillus strains, and advances in downstream processing techniques. Key applications in pharmaceuticals, agriculture, and environmental management are discussed, highlighting its role in drug delivery systems, as a biocontrol agent, and in wastewater treatment. Future perspectives include enhancing production efficiency through synthetic biology, expanding its application scope, and addressing economic and regulatory challenges to facilitate broader adoption. The integration of innovative technologies and multidisciplinary approaches is crucial for the sustainable development and commercial success of γ‐PGA microgel. [ABSTRACT FROM AUTHOR]

The beneficial effects of feeding probiotic Bacillus subtilis DSM 32315 (BS) and Bacillus velezensis CECT 5940 (BV) to chickens in vivo are well-documented, with potential immune modulation as a key mechanism. In this study, we investigated the direct interactions of chicken peripheral blood mononuclear cells (PBMCs) with BS or BV in vitro through whole transcriptome profiling and cytokine array analysis. Transcriptome profiling revealed 20 significantly differentially expressed genes (DEGs) in response to both Bacillus treatments, with twelve DEGs identified in BS-treated PBMCs and eight in BV-treated PBMCs. Pathway analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated significant regulation of immune-related pathways by both BS and BV. Notably, BS treatment upregulated genes associated with immune cell surface markers (CD4, CD25, CD28), anti-inflammatory cytokine interleukin-10 (IL-10), and C-C motif chemokine ligand 5 (CCL5), while downregulating the gene encoding pro-inflammatory IL-16. BV treatment similarly affected genes associated with immune cell surface markers, IL-16, and CCL5, with no impact on the gene encoding IL-10. Both treatments induced higher expression of the gene encoding the avian β-defensin 1 (AvBD1). The results of this in vitro study indicate an immunomodulatory effect of BS and BV in chicken PBMCs by regulating genes involved in anti-inflammatory, bacteriostatic, protective, and pro-inflammatory responses. Consequently, BS and BV may serve to augment the immune system's capacity to defend against infection by modulating immune responses and cytokine expression. Thus, the administration of these probiotics holds promise for reducing reliance on antimicrobials in farming practices. [ABSTRACT FROM AUTHOR]

The application of Bacillus spp. as probiotics in the swine industry, particularly for piglet production, has garnered significant attention in recent years. This review aimed to summarized the role and mechanisms of Bacillus spp. in promoting growth and maintaining gut health in piglets. Bacillus spp. can enhance intestinal barrier function by promoting the proliferation and repair of intestinal epithelial cells and increasing mucosal barrier integrity, thereby reducing the risk of pathogenic microbial invasion. Additionally, Bacillus spp. can activate the intestinal immune system of piglets, thereby enhancing the body's resistance to diseases. Moreover, Bacillus spp. can optimize the gut microbial community structure, enhance the activity of beneficial bacteria such as Lactobacillus, and inhibit the growth of harmful bacteria such as Escherichia coli, ultimately promoting piglet growth performance and improving feed efficiency. Bacillus spp. has advantages as well as challenges as an animal probiotic, and safety evaluation should be conducted when using the newly isolated Bacillus spp. This review provides a scientific basis for the application of Bacillus spp. in modern piglet production, highlighting their potential in improving the efficiency of livestock production and animal welfare. [ABSTRACT FROM AUTHOR]

Around 80% of the food consumed worldwide is provided by agriculture, and almost 30% of these products are affected by phytopathogenic agents, which cause numerous plant diseases. Microorganisms have been used as biocontrol agents to eliminate or decrease damage caused by phytopathogens. For the application of biocontrol agents, such as strains of Bacillus velezensis , several parameters need to be considered, including their habitat and molecular and biochemical conditions, such as plant growth promotion and antifungal activity. B. velezensis strains also have potential as control agents against nematodes in greenhouse cultivation, as probiotic supplements for feed, to pretreat lignocellulosic materials, or in wastewater treatments through the enzymes they produce. Many microorganisms have been reported as bioagents for producing ecofriendly, cost-effective, and safe products. Some Bacillus species of bacteria can be used in agricultural applications. Bacillus velezensis in particular has shown promising results for controlling destructive phytopathogens and in biofungicide manufacturing. Some B. velezensis strains can promote plant growth and display antibiotic activities against plant pathogen agents. In this review, we focus on the often-overlooked potential properties of B. velezensis as a bioagent for applications that will extend beyond the traditional agricultural uses. We delve into its versatility and future prospects, the challenges such uses may encounter, and some drawbacks associated with B. velezensis -based products. [ABSTRACT FROM AUTHOR]

We established confrontations between two different fungi, i.e., the maize anthracnose and stalk rot pathogen Colletotrichum graminicola, and the ubiquitous fungus Aspergillus nidulans, and different biocontrol species, i.e., Bacillus subtilis, Bacillus velezensis, and Bacillus amyloliquefaciens. In all fungus–bacterium confrontations tested, growth arrest and, thus, distance inhibition was observed on solid substrata. LC–MS/MS analyses of culture filtrates suggested formation of several metabolites only synthesized in confrontations. Interestingly, microscopy of fungal hyphae grown in liquid medium showed protrusions and color changes occurred only in media harboring fungus-bacterium confrontations. These observations indicate metabolic re-programming and suggest formation of putative secondary metabolites in interactions involving microbial biocontrol agents. [ABSTRACT FROM AUTHOR]

Bacterial blight in pomegranate, caused by Xanthomonas citri pv. punicae (Xcp), is one of the most devastating diseases, leading to substantial economic losses in pomegranate production. Methods for blight management in pomegranate production are scarce and not well established. To date, the major control strategy is targeting the pathogen with antibiotics and copper-based compounds. However, excessive use of antibiotics has resulted in the development of antibiotic resistance in the field population of Xcp. Hence, as a means of eco-friendly and sustainable management of bacterial blight, the use of native endophytes was investigated under field conditions in the current study. Endophytic bacteria were isolated from micro-propagated nodal explants of pomegranate and were identified as Bacillus haynesii, B. tequilensis, and B. subtilis. They were found to produce volatiles that inhibited Xcp growth during in vitro antibiosis assay. GC–MS-based volatile profiling revealed the presence of several bioactive compounds with reported antimicrobial activities. These endophytes (CFU of 108/mL) were then spray-inoculated on leaves of 6-month-old pomegranate plants in the polyhouse. They were found to induce ROS-scavenging enzymes such as catalase and peroxidase. This alteration was a manifestation of host tissue colonization by the endophytes as ROS scavenging is one of the mechanisms by which endophytes colonize the host plants. Furthermore, two-season field trials with endophytes for blight control resulted in a reduction of disease index by 47–68%, which was considerably higher than the reduction due to the chemical immune modulator (2-bromo-2-nitro-1, 3-propanediol) currently being recommended for blight control. In addition, these endophytes also exhibited reduced sensitivity to this immune modulator; thus, the current study advocates the use of B. haynesii, B. subtilis, and B. tequilensis as biocontrol agents for bacterial blight of pomegranate either alone or as a part of integrated disease management.

Bacillus pseudomycoides, Paenibacillus polymyxa, and B. velezensis are potent bacterial endophytes, which typically exhibit host-specific interactions. However, comparative studies of these endophytes in vitro and in planta in non-host crops are lacking. Therefore, in this study, we evaluated the potential of endophytes B. pseudomycoides strain HP3d, P. polymyxa strain PGSS1, B. velezensis strain A6, and P42, isolated from various crop ecosystems in promoting plant growth and inducing systemic resistance against early blight disease in tomato. In vitro, endophytes exhibited 44.44–55.56% and 37.50–87.50% inhibition of Alternaria solani in dual culture and volatilome bioassay, respectively. In the glasshouse, individual and combined applications via seed treatment (ST), seedling dip (SD), and foliar spray (FS) significantly enhanced shoot growth (23.63–57.61%), root growth (43.27–118.23%), number of leaves (77.52–93.58%), number of shoots (33.42–45.28%) and root dry matter (42.17–43.86%), reducing early blight (PDI) by 70.95–76.12% compared to uninoculated control. Enzymatic activities, including such as polyphenol oxidase (30–40 fold), peroxidase (65.00–75.00 fold), superoxide dismutase (34.20–37.20 fold) and phenylalanine ammonia-lyase (44.44–45.56 fold) were elevated post-inoculation in endophytes treated tomato plants challenged with A. solani compared to control treated only with A. solani and declined after the fifth day. The total chlorophyll content declined from the 0th to the 10th day, but endophyte treated plants exhibited lesser reductions (2.03–2.09) than uninoculated control. Field trials confirmed the glasshouse findings, showing reduced early blight and improved growth parameters in tomato where the ST + SD + FS combination emerged as the most effective treatment for all endophytes showing 1.06–1.88 fold increase in fruit yield per plant and 28.92–32.52% decrease in PDI compared to untreated control. Thus, the study highlights the broad-spectrum potential of these strains in promoting plant growth and controlling early blight in tomato, demonstrating non-host specificity. These endophytes offer eco-friendly alternatives to chemical pesticides, supporting sustainable agriculture. Their success in field trials suggests the potential for commercialization and large-scale use across diverse crops and pave the way for further interdisciplinary research to optimize their application in integrated pest management strategies.

Non-hormone-treated beef steers (n = 1625; 371 ± 8.4 kg) were used to determine the impact of a direct-fed microbial (DFM) on growth performance, carcass characteristics, health parameters, and economic outcomes in finishing beef cattle. Steers were blocked based on initial BW, sorted into three optimal marketing groups for each day of enrollment, randomly assigned to one of two treatments (12 replicates per treatment), and fed for an average of 133 days before harvest. Treatments included the following: (1) control (CON) and (2) 50 mg/head per day of a DFM (BDP) containing Lactobacillus animalis 506, Propionibacterium freudenreichii 507, Bacillus licheniformis 809, and Bacillus subtilis 597 (BOVAMINE DEFEND® Plus). Steers were weighed in drafts by pen on a certified scale at closeout, and both pens within a block were harvested on the same day. Carcass characteristics and liver scores were collected upon slaughter. Data were analyzed as part of a completely randomized block design with the pen as the experimental unit. There was no difference in dry matter intake and final body weight between treatments. The BDP steers exhibited a lower number of total outs (deads and removed) throughout the experiment (p < 0.01). Average daily gain (ADG) tended to be greater (p < 0.06), and feed efficiency (p < 0.01) was greater, for steers receiving BDP. Although there were no statistical differences in hot carcass weight and quality grade between treatments, there was a lower incidence of liver abscess scores (p < 0.01) in the BDP steers. These data suggest that BOVAMINE DEFEND® Plus supplementation improves growth performance during the finishing phase, reduces overall mortality, and improves feed to gain efficiency.

Abstract Phosphorus (P) use efficiency in alkaline/calcareous soils is only 20% due to precipitation of P2O5 with calcium and magnesium. However, coating Diammonium Phosphate (DAP) with phosphorus solubilizing bacteria (PSB) is more appropriate to increase fertilizer use efficiency. Therefore, with the aim to use inorganic fertilizers more effectively present study was conducted to investigate comparative effect of coated DAP with PSB strains Bacillus subtilis ZE15 (MN003400), Bacillus subtilis ZR3 (MN007185), Bacillus megaterium ZE32 (MN003401) and Bacillus megaterium ZR19 (MN007186) and their extracted metabolites with uncoated DAP under axenic conditions. Gene sequencing was done against various sources of phosphorus to analyze genes responsible for phosphatase activity. Alkaline phosphatase (ALP) gene amplicon of 380bp from all tested strains was showed in 1% w/v gel. Release pattern of P was also improved with coated fertilizer. The results showed that coated phosphatic fertilizer enhanced shoot dry weight by 43 and 46% under bacterial and metabolites coating respectively. Shoot and root length up to 44 and 42% with metabolites coated DAP and 41% with bacterial coated DAP. Physiological attributes also showed significant improvement with coated DAP over conventional. The results supported the application of coated DAP as a useful medium to raise crop yield even at lower application rates i.e., 50 and 75% DAP than non-coated 100% DAP application which advocated this coating technique a promising approach for advancing circular economy and sustainable development in modern agriculture.

Beneficial endophytic bacteria can suppress the development of insect pests through direct antagonism, with the help of metabolites, or indirectly by the induction of systemic resistance through the regulation of hormonal signaling pathways. Lipopeptides are bacterial metabolites that exhibit direct antagonistic activity against many organisms, including insects. Also, lipopeptides are able to trigger induced systemic resistance (ISR) in plants against harmful organisms, but the physiological mechanisms of their action are just beginning to be studied. In this work, we studied ten strains of bacteria isolated from the tissues of wheat and potatoes. Sequencing of the 16S rRNA gene showed that all isolates belong to the genus Bacillus and to two species, B. subtilis and B. velezensis. The genes for lipopeptide synthetase – surfactin synthetase (Bs_srf ), iturin synthetase (Bs_ituA, Bs_ituB) and fengycin synthetase (Bs_fenD) – were identified in all bacterial isolates using PCR. All strains had high aphicidal activity against the Greenbug aphid (Schizaphis graminum Rond.) due to the synthesis of lipopeptides, which was proven using lipopeptiderich fractions (LRFs) isolated from the strains. Endophytic lipopeptide-synthesizing strains of Bacillus spp. indirectly affected the viability of aphids, the endurance of plants against aphids and triggered ISR in plants, which manifested itself in the regulation of oxidative metabolism and the accumulation of transcripts of the Pr1, Pr2, Pr3, Pr6 and Pr9 genes due to the synthesis of lipopeptides, which was proven using LRF isolated from three strains: B. subtilis 26D, B. subtilis 11VM, and B. thuringiensis B-6066. We have for the first time demonstrated the aphicidal effect of fengycin and the ability of the fengycin-synthesizing strains and isolates, B. subtilis Ttl2, Bacillus sp. Stl7 and B. thuringiensis B-6066, to regulate components of the pro-/antioxidant system of aphid-infested plants. In addition, this work is the first to demonstrate an elicitor role of fengycin in triggering a systemic resistance to S. graminum in wheat plants. We have discovered new promising strains and isolates of endophytes of the genus Bacillus, which may be included in the composition of new biocontrol agents against aphids. One of the criteria for searching for new bacteria active against phloem-feeding insects can be the presence of lipopeptide synthetase genes in the bacterial genome.

Biologicals and fungicides were evaluated for the control of grey mould in detached fruit in semi‐hydroponic strawberry cultivation. Bacillus subtilis (Serenade, Bio‐Baci, Bio‐Imune), B. amyloliquefaciens (No‐Nema), B. pumilus, B. velezensis (Bombardeiro, BTP 11–19 and BTP 135–19) were compared to the fungicide fluazinam in detached fruit assays. After treatment, fruits were inoculated with 30 μL of a 105 spores mL−1 suspension and incubated in a growth chamber. The relative risk for symptom expression in the treatments in relation to the control was estimated by survival analysis. In the field experiment, Serenade, No‐Nema, Bio‐Imune, Bombardeiro and BTP 11–19, the fungus Clonostachys rosea, procymidone, boscalid, fluazinam, pyrimethanil and cyprodinil + fludioxonil were tested. Biological products were sprayed every 7 days and fungicides at intervals of 14 days. Disease incidence (field and postharvest) and yield were evaluated. In the detached fruit assay, the fungicide fluazinam, followed by the biological products No‐Nema and Bio‐Imune, reduced the relative risk for symptom expression. In the field, cyprodinil + fludioxonil was the most efficacious at harvest. However, no differences in yield were observed. In postharvest, all fungicides in addition to C. rosea, No‐Nema and Bombardeiro reduced the incidence compared to the control during the main production peak (second), and cyprodinil + fludioxonil mixture was the most effective during the season. However, some biological products can be incorporated into an integrated management to reduce postharvest losses. [ABSTRACT FROM AUTHOR]

In this study, we investigated native soil antagonists and the exotic Bacillus thuringiensis (Bt) in their effectiveness against chili bacterial pathogens, specifically Pseudomonas syringae and Xanthomonas vesicatoria. Putative native soil antagonists were isolated through plating heat-shocked (60 °C) serial dilutions on nutrient agar plates. Among these isolates, two (SK, CM) were further characterized based on phenotypic and biochemical traits, revealing gram-positive and catalase-positive characteristics, while being negative for urease, oxidase, and arginine dihydrolase. To evaluate the efficacy of SK, CM, and exotic Bt against P. syringae and X. vesicatoria, a dual culture confrontational assay was conducted. SK, CM, and Bt were found to restrict the growth of X. vesicatoria, not P. syringae. Consequently, further tests were exclusively performed with X. vesicatoria. Chemical compatibility with copper sulfate, topsin M, and sodium benzoate was assessed using the poisoned food technique, revealing inhibitory effects on microbial growth except for topsin M. Antibiotic sensitivity testing (erythromycin, streptomycin, tetracycline, penicillin) of X. vesicatoria, SK, CM, and Bt was carried out using the disk diffusion method. Results indicated a minimum zone of inhibition (0 mm) against penicillin and a maximum (29 mm) against streptomycin. The efficacy of antagonists was also tested in planta using detached leaf and seedling inoculation methods. Pre-inoculating leaves of a susceptible chili cultivar with antagonists and subsequently re-inoculating with X. vesicatoria demonstrated that, except for the positive control, leaves remained asymptomatic after 7 days post-inoculation. A pot experiment involving soil drenching and foliar spray inoculation further confirmed that plants initially treated with antagonists exhibited resistance against subsequent pathogen application compared to the positive control. In conclusion, this pilot study revealed that native putative Bacillus spp. isolates (SK, CM) and commercial exotic Bt have the potential to counteract X. vesicatoria in both local and distant tissues. [ABSTRACT FROM AUTHOR]

Simple Summary: Scientific research and industry support for DFMs have been growing steadily, with studies consistently demonstrating their ability to improve nutrient digestibility and overall performance in beef and dairy cattle. By combining different bacterial strains, DFMs can enhance immune response, increase feed efficiency, and improve carcass characteristics in beef cattle. Lactobacillus and Baciillus strains have emerged as popular choices for their beneficial effects on ruminal fermentation, stability, and enzymatic activity. These bacteria improve cattle's nutrient digestion and overall performance. A novel DFM mixture called BOVAMINE DEFEND® Plus, containing a combination of L. animalis 506, P. freudenreichii 507, B. licheniformis 809, and B. subtilis 597, has shown promising results in improving beef cattle health and performance and a reduction in liver abscesses. BOVAMINE DEFEND® Plus shows multifaceted benefits that suggest the potential to revolutionize livestock agriculture by promoting economic viability and animal health within a probiotic. Continued research efforts will shed more light on the broader implications of this novel DFM mixture, shaping the future of sustainable and efficient beef production practices. Non-hormone-treated beef steers (n = 1625; 371 ± 8.4 kg) were used to determine the impact of a direct-fed microbial (DFM) on growth performance, carcass characteristics, health parameters, and economic outcomes in finishing beef cattle. Steers were blocked based on initial BW, sorted into three optimal marketing groups for each day of enrollment, randomly assigned to one of two treatments (12 replicates per treatment), and fed for an average of 133 days before harvest. Treatments included the following: (1) control (CON) and (2) 50 mg/head per day of a DFM (BDP) containing Lactobacillus animalis 506, Propionibacterium freudenreichii 507, Bacillus licheniformis 809, and Bacillus subtilis 597 (BOVAMINE DEFEND® Plus). Steers were weighed in drafts by pen on a certified scale at closeout, and both pens within a block were harvested on the same day. Carcass characteristics and liver scores were collected upon slaughter. Data were analyzed as part of a completely randomized block design with the pen as the experimental unit. There was no difference in dry matter intake and final body weight between treatments. The BDP steers exhibited a lower number of total outs (deads and removed) throughout the experiment (p < 0.01). Average daily gain (ADG) tended to be greater (p < 0.06), and feed efficiency (p < 0.01) was greater, for steers receiving BDP. Although there were no statistical differences in hot carcass weight and quality grade between treatments, there was a lower incidence of liver abscess scores (p < 0.01) in the BDP steers. These data suggest that BOVAMINE DEFEND® Plus supplementation improves growth performance during the finishing phase, reduces overall mortality, and improves feed to gain efficiency. [ABSTRACT FROM AUTHOR]

The study aims to investigate plant growth promotion (PGP) activities of thermophilic bacteria isolated from the Jakrem hot spring in Meghalaya, North-East India, and determine their effect on Brassica juncea's growth. The bacteria were isolated by a culture-dependent approach following a serial dilution method in a nutrient agar medium. All the isolates were determined for PGP attributes such as indole acetic acid, phosphate solubilization, hydrolytic enzymes, and siderophore production. The potent bacterial isolates were characterized by 16S rDNA sequencing and phylogenetic analysis. Altogether, 53 bacterial isolates were obtained, most belonging to the genus Bacillus. Of the total isolates, 37.7% exhibited both PGP and hydrolytic enzyme activities. Three isolates, namely JAB1, JAB8, and JAB100, showed promising PGP and were identified as Bacillus velezensis, B. proteolyticus, and Bacillus sp., respectively. The PGP attributes of these isolates were determined in vivo on B. juncea, and their effects were measured in terms of shoot and root length biomass and biochemical contents. It was observed that combined inoculation of all three isolates significantly enhanced the growth and development of B. juncea, evident by increased shoot and root length, fresh and dry weight, and higher levels of protein, phenol, flavonoid, and chlorophyll content compared to the control. In conclusion, the study highlights the potential application of thermophilic Bacillus spp. from hot springs as bioinoculants to enhance crop productivity in sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Phosphorus (P) use efficiency in alkaline/calcareous soils is only 20% due to precipitation of P2O5 with calcium and magnesium. However, coating Diammonium Phosphate (DAP) with phosphorus solubilizing bacteria (PSB) is more appropriate to increase fertilizer use efficiency. Therefore, with the aim to use inorganic fertilizers more effectively present study was conducted to investigate comparative effect of coated DAP with PSB strains Bacillus subtilis ZE15 (MN003400), Bacillus subtilis ZR3 (MN007185), Bacillus megaterium ZE32 (MN003401) and Bacillus megaterium ZR19 (MN007186) and their extracted metabolites with uncoated DAP under axenic conditions. Gene sequencing was done against various sources of phosphorus to analyze genes responsible for phosphatase activity. Alkaline phosphatase (ALP) gene amplicon of 380bp from all tested strains was showed in 1% w/v gel. Release pattern of P was also improved with coated fertilizer. The results showed that coated phosphatic fertilizer enhanced shoot dry weight by 43 and 46% under bacterial and metabolites coating respectively. Shoot and root length up to 44 and 42% with metabolites coated DAP and 41% with bacterial coated DAP. Physiological attributes also showed significant improvement with coated DAP over conventional. The results supported the application of coated DAP as a useful medium to raise crop yield even at lower application rates i.e., 50 and 75% DAP than non-coated 100% DAP application which advocated this coating technique a promising approach for advancing circular economy and sustainable development in modern agriculture. [ABSTRACT FROM AUTHOR]

Fruit discoloration and fruit rot disease in longan is a serious disease caused by the pathogenic fungi Pestalotiopsis oxyanthi and Lasiodiplodia pseudotheobromae. This study investigated the potential of antagonistic bacteria as an eco-friendly alternative to traditional fungicides for managing longan diseases caused by these fungal pathogens. Two bacterial isolates, UP-JLS050 and UP-JLS067, demonstrated significant inhibitory activity against the pathogenic fungi P. oxyanthi and L. pseudotheobromae, with high inhibitory activity. The bacterial strains were isolated from leaves and soil in a longan garden, and dual culture methods showed that the isolates UP-JLS050 and UP-JLS067 exhibited the highest inhibitory activity on the fungal pathogens, with percentage inhibitions of 72.67 ± 2.31 and 70.37 ± 1.28 %, respectively. Biochemical methods and molecular techniques, including sequencing of the 16S rDNA gene, were then used to identify the isolates. This confirmed their similarity to Bacillus subtilis and Bacillus amyloliquefaciens with 100 and 99 % identity, respectively. In vitro tests on longan fruit indicated that these antagonistic bacteria, administered at a concentration of 108 CFU/mL, significantly reduced disease incidence by up to 45 % after 9 days of incubation. The incubation of B. subtilis (UP-JLS050) and B. amyloliquefaciens (UP-JLS050) reduced disease incidence by 45 ± 5.77 and 32.5 ± 5.00 %, respectively. [ABSTRACT FROM AUTHOR]

Bacteria play an essential role in various industrial processes, including food, medicine, and detergents, due to their ability to produce protease, a hydrolytic enzyme. This study aimed to identify and characterize protease-producing bacterial strains isolated from garden soil, evaluate their antibiotic susceptibility, and optimize conditions for enhanced protease production. Using skimmed milk agar medium and the gelatin hydrolysis method, 7 bacterial strains (S1, S2, S3, S4, S5, S6, and S7, respectively) were identified for protease production in garden soil. The bacteria were identified based on morphological studies, biochemical characterization, and the BIOLOG™ system, and the isolates were determined to be Bacillus cereus (S1), B. thuringiensis (S2), B. subtilis (S3), B. amyloliquefaciens (S4), Pseudomonas aeruginosa (S5), Macrococcus brunensis (S6), and B. schlegelii (S7). The antibiotic susceptibility test, performed using the Kirby-Bauer agar disc diffusion method, revealed that all isolates were resistant to penicillin, nitrofurantoin, and metronidazole. Additionally, B. subtilis and P. aeruginosa demonstrated antagonistic activity against pathogens. Optimal conditions for protease production were found to be a temperature range of 30°C to 40°C and a pH range of 6.5–7.5. Under these conditions, B. cereus (2.19 U/ml) and B. thuringiensis (2.12 U/ml) exhibited the highest protease activity. Further characterization of protease activity in B. cereus, P. aeruginosa, and M. brunensis under different physiological parameters revealed that maximum activity occurred within a pH range of 5.0–6.0 and temperatures between 30°C and 40°C. Protease activity increased in the presence of calcium (CaCl2) but decreased with the addition of urea. These findings underscore the significant industrial applications of proteases produced by these bacterial strains.

ABSTRACT Handroanthus chrysotrichus (Mart. ex DC.) Mattos, popularly known as the golden trumpet tree, is a native tree of Brazil with exuberant flowering. It is used for urban afforestation and reforestation of degraded areas, and its wood is destined for several purposes. In order to develop vigorous plants after planting, it is essential to produce high-quality seedlings, which can be obtained using rhizobacteria. As renewable sources, rhizobacteria exhibit growth-promoting properties, facilitate nutrient uptake and/or solubilization, and contributes to the production of phytohormones, while also serving as pathogen controllers and mitigators of abiotic stress. These attributes collectively enable the establishment of a sustainable production system for producing vigorous and rapidly growing seedlings. This study aimed to evaluate the effect of plant growth-promoting rhizobacteria in the production of H. chrysotrichus seedlings. The experimental design followed a completely randomized setup. The treatments consisted of microorganisms (Bacillus subtilis, Bacillus megaterium, Bacillus amyloliquefaciens, and Azospirillum brasilense) plus the absence of microorganisms - control; four repetitions and ten plants-per-plot. The parameters evaluated were shoot height; stem diameter; root length; shoot, root, and total dry matter; leaf number and leaf area, as well as chlorophyll content; minimum and maximum fluorescence; and maximum quantum efficiency of photosystem II; shoot height/stem diameter ratio and Dickson’s Quality Index. The B. amyloliquefaciens inoculation promoted an increase in seedling shoot height, stem diameter, root length, leaf area, shoot, root, and total dry matter and also increased the Dickson Quality Index. It can be concluded that B. amyloliquefaciens is the most efficient inoculant for producing golden trumpet tree seedlings, followed by A. brasilense.

Antibiotic resistance in soil introduced by organic fertilizer application pose a globally recognized threat to human health. Insect organic fertilizer may be a promising alternative due to its low antibiotic resistance. However, it is not yet clear how to regulate soil microbes to reduce antibiotic resistance in organic fertilizer agricultural application. In this study, we investigated soil microbes and antibiotic resistome under black soldier fly organic fertilizer (BOF) application in pot and field systems. Our study shows that BOF could stimulate ARB (antibiotic resistant − bacteria) − suppressive Bacillaceae in the soil microbiome and reduce antibiotic resistome. The carbohydrate transport and metabolism pathway of soil Bacillaceae was strengthened, which accelerated the synthesis and transport of polysaccharides to form biofilm to antagonistic soil ARB, and thus reduced the antibiotic resistance. We further tested the ARB − suppressive Bacillus spp. in a microcosm assay, which resulted in a significant decrease in the presence of ARGs and ARB together with higher abundance in key biofilm formation gene (epsA). This knowledge might help to the development of more efficient bio-fertilizers aimed at mitigating soil antibiotic resistance and enhancing soil health, in particular, under the requirements of global “One Health”.

The aim of this work was to evaluate the effect of 40 endophytic bacteria isolates on the control of Meloidogyne javanica in ‘Prata-Anã’ banana seedlings. Two experiments were carried out in a completely randomized design with eight replicates. In each trial, 20 bacteria isolates and control were evaluated. Bacterial suspensions were applied to substrates during the acclimatization of seedlings at 15 and 30 days. On the 31st day, seedlings were transplanted into pots and soil was infested with M. javanica egg suspension at 8 days. After 90 days, the following variables were evaluated: number of galls, egg masses, eggs per root, reproduction factor (RF), second-stage juveniles, and shoot dry matter. The results of nematological variables were submitted to Principal Components Analysis. In trial I, the variables that most contributed to data variability were as follows: number of eggs and RF. In trial II, RF had greater influence. Of the 40 isolates evaluated, 39 reduced RF, and of the 20 isolates evaluated in the first trial, all reduced the number of eggs per root. Bacillus methylotrophicus EB26, Bacillus cereus EB25, and Bacillus sp. EB37 isolates stood out in the control of nematodes, with RF reduction above 80%.

Abstract Background Antimicrobial resistance poses a huge risk to human health worldwide, while Bangladesh is confronting the most severe challenge between the food supply and the huge consumption of antibiotics annually. More importantly, probiotics containing Bacillus spp. are claimed to be an alternative to antimicrobial stewardship programs. However, their antibiotic resistance remains elusive. Thus, we employed the antimicrobial susceptibility test and PCR to assess the prevalence of resistance, including multidrug resistance (MDR) and resito-genotyping of isolated Bacillus spp. Results The phenotypic profile showed that Bacillus spp. were 100% sensitive to gentamicin (2 µg/mL), whereas lowered sensitivity to levofloxacin (67.8%, 0.5–1 µg/mL), ciprofloxacin (62.3%, 0.5–1 µg/mL), clindamycin (52.2%, 0.25–0.5 µg/mL), amoxicillin-clavulanic acid (37.6%, 0.06 µg/mL), azithromycin (33.4%, 1–2 µg/mL), tetracycline (25.6%, 2–4 µg/mL), nitrofurantoin (21.1%, 16–32 µg/mL), co-trimoxazole (19.2%, 2 µg/mL), and erythromycin (18.8%, 0.25–0.5 µg/mL). The strains were completely resistant to penicillin, amoxicillin-clavulanic acid, cefixime, ceftriaxone, vancomycin, and co-trimoxazole, and a species-specific trend was seen in both phenotypic and genotypic resistance patterns. Genotypic resistance indicated prevalence of the bla1 (71.5%), tetA (33%), erm1 (27%), bla TEM (13.1%), bla CTX-M-1/bla CTX-M-2 /sul1 (10.1%), bla SHV (9.6%), and qnrS (4.1%) genes. The β-lactamase resistance gene bla1 was found in all penicillin-resistant (MIC ≥ 32 µg/mL) Bacillus spp. One hundred ninety-one isolates (89.6%) were MDR, with 100% from diarrhea, 90.3% from food, and 88.7% from animal feed. Conclusion Based on the MIC value and profile analysis of antibiotic resistance genes, this is the first study that Bacillus spp. antimicrobial susceptibilities have been identified in Bangladesh, and our study will shed light on the adverse effects of feed-borne Bacillus spp. emerging from animal feed to the food chain. A comprehensive investigation is urgently needed by policymakers on tolerance limits and harmful effects in the animal industry.