Screening of Potential Probiotic Bacteria From Chili Calyx and Detection of Its Probable Bioactive Metabolites

Abstract

Abstract Potential source of non-dairy lactic acid bacteria (LAB) from chili calyx was studied in the current study. The target of the current research involved isolation of potential LAB, its identification, and lastly characterization of the properties of lactic acid bacteria and determining whether they could possess an integral role in the production of metabolites. Initially, the isolated bacteria were examined for physical and microscopic properties. The bacteria were found to be gram negative and catalase positive during the initial screening. SEM image confirmed the bacteria to have rod shape structure. The isolate was further exposed to a stress environment that included various levels of bile, phenol, acid, and simulated gastric conditions. Among all of the different parameters, the LAB isolate demonstrated a survival percentage of higher than 70%. By analysing the isolate for hemolytic assay and antibacterial activity, the safety characteristics were assessed later. The isolate's preliminary characteristics supported that it was safe for usage because it did not exhibit any zone formation or γ-hemolysis in the hemolytic assay. In terms of antimicrobial activity, all strains were able to suppress the enteric pathogens, which was confirmed by the existence of a zone. Following the aforementioned tests, 16S rRNA gene-sequencing was performed and phylogenetic analysis identified the isolate as Enterobacter cloacae. The LAB's ability to produce secondary metabolites was finally analysed. After being extracted, the secondary metabolites were recognized by GCMS and confirmed by FTIR.