Probiotics are living microorganisms when administered in adequate amounts confer health benefits to the host. In the present study, a soil isolate was identified as Bacillus subtilis based on the 16S rRNA sequencing. In probiotic functional characterization (in vitro), B. subtilis SKB/2074 produced 10 different enzymes, was stable under simulated gastric conditions (pH 2.5/1-3 hr), bile salt (0.05-0.3% w/v), and temperature (40-90 degrees C) conditions. B. subtilis SKB/2074 cells were non-hemolytic, found susceptible to the 30 antibiotics, and showed antimicrobial activity against Escherichia coli, Salmonella typhimurium, and Clostridium perfringens. In in vivo studies, B. subtilis SKB/2074 demonstrated encouraging results to reverse E. coli and castor oil incited diarrhea in Wistar rats and Albino mice, respectively. Histopathological studies exhibited restoration of damaged mucosal epithelium cells and recovers veracity of goblet cells (colon). B. subtilis SKB/2074 exhibited immunomodulatory effects (increased immunoglobulins in blood and weight of spleen and thymus) and significant antioxidant activity (84.14%), reducing capacity and ascorbate auto-oxidation inhibition effect (95.13%). In poultry field studies, B. subtilis SKB/2074 significantly improved growth performance and lowered mortality rate in broiler chickens. Based on these preliminary scientific assessments B. subtilis SKB/2074 is likely to be used as potential probiotic and antidiarrheal agent in humans and animal healthcare.

The use of plant growth-promoting microorganisms is an effective agricultural practice to improve plant growth, especially under abiotic stress. In this study, the combined impact of three plant growth-promoting bacteria (PGPB) namely Brevibacterium halotolerans (Sd-6), Burkholderia cepacia (Art-7), Bacillus subtilis (Ldr-2) were tested with Trichoderma harzianum (Th) (possessing ACC deaminase producing activity) in Ocimum basilicum L. cv. Saumya to reduce drought-induced damages to the plants under different level of drought stress [i.e. wellwatered (100 %), moderate (60 %), severe (40 %)]. These PGPB strains, along with Th, were found to be tolerant against osmotic stress when tested in growth media containing different concentrations of polyethylene glycol (PEG 8000), and all were found to endure -0.99 MPa water potential. Compared to non-inoculated control, Th+Ldr-2 treatment improved fresh herb weight (62.45 %) and oil content (61.54 %) and higher photosynthetic rate under severe drought. Besides, in relation to control, the above treatment enhanced nutrient uptake, reduced ABA, ACC as well as ethylene levels and increased IAA content in addition to an increase in important constituents of essential oil, indicating better performance in terms of plant growth under drought. Higher RWC, decreased MDA, and reduced antioxidant activities in Th+Ldr-2 treated plants compared to non-inoculated control under drought support the mechanism of the microbes providing tolerance against drought. Colony forming unit of microbes and scanning electron microscopy (SEM) study support the effective colonisation behaviour of Th+Ldr-2, which protects plants against drought stress. A consortium of diverse microbes, found to improve plant growth under drought through increased nutrient uptake, reducing the levels of ACC and ABA, improving the content of IAA, antioxidant enzymes probably reducing the effect of drought stress and improving plant biomass could be a useful tool to reduce drought-induced losses in crop plants.

Using chemical fertilizers in agriculture increases production and improves the quality of the product; however, their higher usage globally has brought forth damage to ecosystems. Using biofertilizers is a better strategy to reduce the use of chemical fertilizers and ultimately increase soil fertility. This study aimed to isolate, identify, and characterize bacteria from the soil rhizosphere of medicinal plants ( Rumex tuberosus L. and Verbascum sp.) for in vivo screening. Nitrogen fixation, phosphate solubilization, HCN, ammonia levels, Lipase, protease, catalase and siderophore production biochemical tests were also conducted. The two isolates that gave positive results from the biochemical tests were chosen out of 25 for further experiments. Based on 16S rRNA sequencing analysis the isolated organisms were identified as Alcaligenes faecalis Go1 (Accession No. OP001725) and Bacillus subtilis T11 (Accession No. OP218376). The compound fertilizer NPK was used as the positive control for field experiments, while selected stains were individually and in-combination were tested on potato crops as inoculum, over two successive cropping seasons. Plant height, number of tubers per plant, chlorophyll content, and tuber weight all increased for both isolated bacterial strains. The quality of the potato tubers was checked through visual observation for the presence or absence of disease symptoms. The treated tubers exhibited excellent quality, remaining free from any signs of disease, however, the control tubers showed infections with ( Streptomyces scabiei, Fusarium sp ., F. solani and Erwinia amylovora). The soil analyzed after harvesting both bacteria increased percentages of P, Ca2+, Mg2+, Na+, K+, SO4, total nitrogen content and total organic matter. The findings showed that the tested bacterial isolates could replace the use of chemical fertilizers in the production of potatoes.

Oil and gas drilling waste fluid are an alkaline mixture with complex composition that can be hazardous to plants if leakage occurs during transportation and disposal. Bacillus subtilis is well-known for its adaptable to adversity and its beneficial effect on plants and soil. In this study, the novel ultra-slippery water-based drilling fluids were evaluated as potentially hazardous liquids capable of inhibiting ryegrass (Lolium perenne) germination and growth. However, the combination of ryegrass and B. subtilis successfully decreased the negative effects of waste drilling fluid stress, while increasing the levels of antioxidant enzymes and osmotic regulatory substances, resulting in improved ryegrass germination and growth. Furthermore, B. subtilis enhanced the activation of nitrogen, phosphorus, and potassium in the soil, which improved soil conditions and promoted ryegrass development. This study proposes a novel approach for combined remediation of waste drilling fluid pollution in oil and gas drilling sites using microbial agents and plants, while also furnishing resources for enhancing ryegrass resilience and facilitating ecological restoration.

The widespread prevalence of saline environments poses a significant global environmental challenge. Salt stress, induced by saline soils, disrupts soil microecology and affects the plant-microbe-soil cycling process. Utilizing microbial fungicides stands as a primary strategy to mitigate salt stress-induced damage to plants and soils. This study investigated the influence of Bacillus subtilis (Bs) inoculation on the microbial community, assembly processes, and functional changes in bacteria and fungi in Glycyrrhiza uralensis Fisch. (licorice) seedlings under varying salt stress levels, primarily employing microbiomics techniques. Soil enzyme activities displayed a declining trend with increasing salt stress, which was mitigated by Bs inoculation. Microbiome analysis revealed a significant increase in bacterial and fungal operational taxonomic units, particularly in Ascomycetes and Nitrogen-fixing Bacteria, thereby enhancing soil denitrification. The abundance of Proteobacteria, Actinobacteriota, Bacteroidota, and Firmicutes in bacteria, as well as Ascomycota in fungi, increased with higher salt stress levels, a process facilitated by Bs inoculation. However, functional predictions indicated a reduction in the relative abundance of Dung Saprotrophs with Bs inoculation. Salt stress disrupted soil assembly processes, showcasing a continuous decline in diffusion limitation with increased salt concentration, where Bs inoculation reached a peak under moderate stress. In summary, this research elucidates the communication mechanism of Bs in enhancing salt tolerance in licorice from a microbiome perspective, contributing to a comprehensive understanding of abiotic and biotic factors.

Aims This study aimed to assess the effects of phenolic acid-degrading bacteria strains on phenolic acid content, plant growth, and soil bacterial community in phenolic acid-treated soils.Methods and results The strain of interest coded as B55 was isolated from cucumber root litter, and its degradation rates of ferulic acid and p-coumaric acid were 81.92% and 72.41% in Luria-Bertani solution, respectively, and B55 was identified as Bacillus subtilis. B55 had plant growth-promoting attributes, including solubilization of inorganic phosphate and production of siderophore and indole acetic acid. Both ferulic acid and p-coumaric acid significantly restrained an increase in cucumber seedling dry biomass, while the B55 inoculation not only completely counteracted the damage of phenolic acids to cucumber seedlings and decreased the content of ferulic acid and p-coumaric acid in soil, but also promoted cucumber seedlings growth. Amplicon sequencing found that B55 inoculation changed the cucumber rhizosphere bacterial community structure and promoted the enrichment of certain bacteria, such as Pseudomonas, Arthrobacter, Bacillus, Flavobacterium, Streptomyces, and Comamonas.Conclusions B55 not only promoted cucumber seedling growth, and decreased the content of ferulic acid and p-coumaric acid in soil, but it also increased the relative abundance of beneficial microorganisms in the cucumber rhizosphere.

Microbially induced calcite precipitation has garnered significant attention in recent years as a promising and environmentally friendly process for addressing sand stabilization and soil consolidation. While its potential to stabilize sand dunes and mitigate soil liquefaction is well-documented, the applicability of MICP in the consolidation of stone materials has not been thoroughly investigated. Tuffs, which are silicate-laden pyroclasts, have historical significance as hybrid materials for cement, emphasizing their importance in cultural heritage. In previous MICP applications, there has been a lack of exploration regarding the incorporation of urease-producing bacteria (UPB) into Tuffs. Consequently, the potential of MICP in substrates such as Tuffs has been largely overlooked. The primary objective of this study is to assess the feasibility of incorporating UPB into Tuffs as a consolidating agent to facilitate calcium carbonate precipitation. We aim to investigate the microstructure of the resulting polymorphs and the previously unknown mechanism of increased resistance to W-D cycles in the treated samples at the nanoscale. In this study, we compared the cementation response of Tuff when subjected to two different UPBs by evaluating changes in key parameters, including capillary water absorption (CWA), cyclic tests such as wet-dry and salt attack, and uniaxial compressive strength. Furthermore, the characteristics of crust formation were examined using FESEM, and an in-depth analysis of the microstructure of the deposited bacterial CaCO3 was conducted. The mechanism of increased W-D resistance in Tuffs reinforced by MICP has not been previously addressed by researchers. Our study demonstrated that the increase in resistance to W-D cycles was more pronounced in samples treated with Bacillus pasteurii. . Further FESEM analysis showed the presence of Bacillus pasteurii spores in the nanopores of the (W-D) exposed samples. N2 adsorption analysis revealed that nanopore alteration occurred only in samples treated with Bacillus pasteurii. . Additionally, Tuffs are prone to disjoining pressure, which occurs in nanopores. Based on these observations, we postulate that the increased resistance to W-D cycles in the samples treated with Bacillus pasteurii was caused by a decrease in disjoining pressure due to the recrystallization of amorphous calcium carbonate (ACC) in the nanopores of the studied Tuff.

Thin plastic films used for packing food materials are unsafe for consumers and are not readily degradable. Single-use plastic films accumulate in the environment and cause adverse effects in the food chain. In this study, Kappaphycus alvarezii, which has the value-added polymer carrageenan, was used for developing a bioplastic film along with the plasticizer polyethylene glycol (PEG 3000). Different concentrations of seaweed were used (3%, 4% and 5% dry weight), of which 4% had a higher tensile strength than the other concentrations. The physical and mechanical properties of the developed plastic films, such as thickness, tensile strength (TS), water vapor transmission rate (WVTR), oxygen transmission rate (OTR) and color, were tested for packaging applications in the food industry. A higher concentration of seaweed increased the WVTR, and a lower concentration increased the OTR. In addition, the biodegradation of the developed bioplastic was tested using isolated deep-sea microbial consortia to meet environmental standards. A deep-sea marine microbial consortium (Bacillus paralicheniformis G1, Bacillus subtilis G2, Bacillus subtilis Z1, and Enterobacter cloacae subsp. dissolvens Z2) degrades seaweed (Kappaphycus alvarezii)-derived bioplastic under buried soil conditions. The maximum degradation (88%) in the 5% (w/v) bioplastic film was observed within 10 days of incubation.

The present study aimed to evaluate the single and combined effects of Si exogenous treatment and Bacillus subtilis subsp. subtilis M1 strain inoculation on rosemary tolerance to low phosphorus (P) availability. Hence, rosemary plants were fertilized with 250 mu mol Ca3HPO4 (stressed plants) or 250 mu mol KH2PO4 (control plants) under Si treatment and B. subtilis M1 strain inoculation. P starvation negatively affected rosemary growth and its P nutrition. However, exogenous Si supply or B. subtilis M1 strain inoculation significantly (P < 0.001) alleviated the deficiency-induced effects and significantly improved rhizogenesis, acid phosphatase activity, P uptake, and eventually dry weight of shoot and root. Moreover, Si-treatment and/or B. subtilis M1 strain inoculation significantly (P < 0.001) reduced the oxidative damage, in terms of malondialdehyde and hydrogen peroxide accumulation. This was found positively correlated with the higher superoxide dismutase activity, and the elevated non-enzymatic antioxidant molecules accumulation, including total polyphenols in Si-treated and inoculated P-deficient plants. Taken together, Si supplementation and/or B. subtilis M1 strain inoculation could be a good strategy to sustain rosemary plant growth under P starvation conditions.

Introduction: Research on Glycyrrhiza uralensis, a nonhalophyte that thrives in saline-alkaline soil and a traditional Chinese medicinal component, is focused on improving its ability to tolerate salt stress to increase its productivity and preserve its Dao-di characteristics. Furthermore, the inoculation of bioagents such as Bacillus subtilis to increase plant responses to abiotic stressors is currently a mainstream strategy. Mitogen-activated protein kinase (MAPK), a highly conserved protein kinase, plays a significant role in plant responses to various abiotic stress pathways. Methods: This investigation involved the identification of 21 members of the GuMAPK family from the genome of G. uralensis, with an analysis of their protein conserved domains, gene structures, evolutionary relationships, and phosphorylation sites using bioinformatics tools. Results: Systematic evolutionary analysis of the 21 GuMAPKs classified them into four distinct subgroups, revealing significant differences in gene structure and exon numbers. Collinearity analysis highlighted the crucial role of segmental duplication in expanding the GuMAPK gene family, which is particularly evident in G. uralensis and shows a close phylogenetic relationship with Arabidopsis thaliana, tomato, and cucumber. Additionally, the identification of phosphorylation sites suggests a strong correlation between GuMAPK and various physiological processes, including hormonal responses, stress resistance, and growth and development. Protein interaction analysis further supported the role of GuMAPK proteins in regulating essential downstream genes. Through examination of transcriptome expression patterns, GuMAPK16-2 emerged as a prospective pivotal regulatory factor in the context of salt stress and B. subtilis inoculation, a finding supported by its subcellular localization within the nucleus. Discussion: These discoveries offer compelling evidence for the involvement of GuMAPK in the salt stress response and for the exploration of the mechanisms underlying B. subtilis' enhancement of salt tolerance in G. uralensis.