AMB Volume 42, Issue 2, 2026 Pages 295-316 https://doi.org/10.59393/amb26420213
Safety Profiling and Probiotic Attributes of Soil-Based Bacillus Species and Their Bioactive Metabolites for Therapeutic Potential
Mathew L.P., Bhukya K.K., Reddy M.P., Nikhil K.
New strains of probiotic Bacillus species are required to meet the growing consumer demand for probiotics. This study aimed to assess the probiotic ability of the Bacillus strain Shouchella clausii (formerly Alkalihlobacillus clausii or Bacillus clausii) ELBC004 was isolated from soil in the Ghat region of the Krishna River, Andhra Pradesh, India. The results indicate that Shouchella clausii (S. clausii) ELBC004 exhibited a noteworthy tolerance at pH 2.0, 3.0, and 4.0 (9.75, 9.30, and 9.20 CFU/mL), 1% bile salts (9.20 CFU/mL), and 8% sodium chloride (12.18 CFU/mL) after 6 hours of incubation. Compared with the reference strain Bacillus subtilis LifeinU® BSCU1, it also displayed greater tolerance to pepsin (8.93 CFU/ mL at pH 2.0) and pancreatin (8.78 CFU/mL at pH 8.0). The isolate ELBC004 exhibited negative results for haemolysis, DNase, lecithinase, gelatinase, and biofilm formation, confirming the safety of the strain. Additionally, it demonstrated significant proteolytic, amylolytic, autolytic, compatibility, and exopolysaccharide-producing abilities. In addition, the isolate ELBC004 showed antibiotic resistance to chloramphenicol (C), rifampicin (RIF), streptomycin (S), tetracycline (T), penicillin (P), sulfadiazine (SZ), amoxacillin (OX), cefepime (CPM), sulfamethizole (SM), and metronidazole (MTZ), and showed strong antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. The strain ELBC004 reduced pathogenic biofilm production, exhibited 56 to 81% 2,2-diphenylpicrylhydrazyl (DPPH) scavenging activity, and demonstrated potent in vitro antidiabetic activity by inhibiting α-amylase (73.26%) and α-glucosidase (68.34%). Gamma-aminobutyric acid (GABA) production was also confirmed. In conclusion, this study identified S. clausii ELBC004 as a potential probiotic strain.
Keywords: Bacillus species, probiotic, antibiotic resistance, antioxidant potential, antidiabetic activity, gamma-aminobutyric acid
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