title: Production and purification of anti-bacterial biometabolite from wild-type Lactobacillus, isolated from fermented bamboo shoot: future suggestions and a proposed system for secondary metabolite onsite recovery during continuous fermentation.
abstract: Wild-type lactobacillus isolated form Khorisa, a fermented bamboo shoot product of Assam, India were evaluated for production anti-bacterial secondary biometabolites, against Staphylococcus aureus. Submerged fermentation technique was used for the production of secondary anti-microbial biometabolite by a single wild-type lactobacillus strain, which tested positive for the release of anti-bacterial factor(s). Crude cell-free supernatant was obtained, followed by extraction in water-immiscible solvents viz., chloroform, hexane, petroleum ether. Chloroform extract of cell-free crude supernatant showed maximum yield (0.054 g/ml) and inhibited all indicator bacterial strains viz., Escherichia coli, Staphylococcus aureus, and Bacillus cereus. Yields of hexane and petroleum ether extract were 0.052 and 0.026 g/ml, respectively. Minimum lethal dose concentration assay of the chloroform extract showed LDmin values at 27, 1.68, and 1.68 mg/ml for E. coli, S. aureus, and B. cereus, respectively. Kill time for all the indicator bacterial strains were less than 12 h. The efficacy of the anti-bacterial substance seemed to depend on the presence of organic acids, particularly lactic acid. Conceptual-based suggestion for the development of an onsite secondary metabolites recovery system during continuous fermentation has also been attempted.
authors.affiliation: Department of Food Engineering and Technology, School of Engineering, Tezpur University, Napaam, Assam, India, laxmikantbadwaik@gmail.com.
authors.forename: Laxmikant S
authors.initials: LS
authors.lastname: Badwaik
authors.forename: Pallab Kumar
authors.initials: PK
authors.lastname: Borah
authors.forename: Sankar C
authors.initials: SC
authors.lastname: Deka
mesh_terms: D000473:Alkanes / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D001409:Bacillus cereus / Q000187:drug effects / Q000254:growth & development; D031723:Bambusa / Q000378:metabolism; D019149:Bioreactors; D002725:Chloroform / Q000737:chemistry; D045424:Complex Mixtures / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D005285:Fermentation; D006586:Hexanes / Q000737:chemistry; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000737:chemistry / Q000378:metabolism*; D059625:Liquid-Liquid Extraction / Q000379:methods; D008826:Microbial Sensitivity Tests; D018520:Plant Shoots / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development
chemical_list: D000473:Alkanes; D000900:Anti-Bacterial Agents; D045424:Complex Mixtures; D006586:Hexanes; D012997:Solvents; D019344:Lactic Acid; D002725:Chloroform; C004544:naphtha