Journal of Biotechnology & Biomaterials
Open Access

Abstract

Lactic acid bacteria (LAB) generally recognized as safe (GRAS) organisms are protective bacteria due to their antagonistic activity against several pathogenic organisms. They also serve as probiotics providing a health benefit on the host. In this study Lactobacillus plantarum subsp. plantarum isolated from fermented idli batter exhibited probiotic potential. The isolate was able to tolerate up to 0.3% of bile for 4- 6 hours and pH 2.5, 3.5, 4.5, 6.5, 7.5 and 8.5. The isolates were able to resist growth against gastric and intestinal fluid. The isolate exhibited good levels of auto-aggregation, co-aggregation and hydrophobicity. The isolates showed resistance towards antibiotics like gentamycin, ciprofloxacin, nalidixic acid and norfloxacin. The isolate showed bile salt hydrolase activity indicating cholesterol lowering capacity and β - galactosidase activity. They are known to produce several low molecular weight compounds having antimicrobial activity such as lactic acid, acid, acetic acid, diacetyl, methylhydantoin, mevalonolactone, cyclic dipeptides, phenyl lactic acid and reuterin etc. The isolate was found to produce a low molecular weight antibacterial compound, which was purified by passing the supernatant of 85% cold acetone precipitation of cell free supernatant through gel permeation chromatography, Sephadex G25 followed by Sephadex G15 column. The active molecule was further purified using Sep-Pak C18 cartridge and purity was checked in HPLC. The compound is readily soluble in aqueous solutions and the structure of the compound was elucidated by LC-MS, H 1 NMR, C 13 NMR in D 2 O and FTIR, while the hydroxyl functional group presence is confirmed by performing proton NMR in DMSO followed by D 2 O. The molecular weight of the compound was 204 daltons and the structure of the compound was determined as 2-hydroxy indole propanamide, which showed good antibacterial activity against both gram positive and gram negative organisms. This compound may have a clinical application as they exhibit wide spectrum of activity.

Biography

Jeevaratnam Kadirvelu has completed his PhD at Indian Institute of Science, Bangalore. He is Professor & Co-ordinator (Microbiology), Department of Biochemistry & Molecular Biology, Pondicherry University. Earlier he has served DRDO for over a period of 23 years. His research area is Pharmacology & Toxicology, Nutrition Biochemistry and Functional foods and Microbial Biochemistry & Biotechnology. He has published more than 60 papers in reputed journals. He is currently guiding 7 students for their PhD in the field of Microbial Biochemistry & Biotechnology