Vol. 12, Issue 11 (2023)

Author(s):
Jitesh Tarak, B Shekhar, B Narsimlu, Sarang Dilip Pophaly and Manorama

Abstract:
Lactic acid bacteria (LAB) composed of a diverse group of microorganisms associated with plants, meat, vegetables and milk. Some carefully selected and characterized microorganism are used for preparation of fermented milk and food product such as Dahi, Acidophilus milk, Yogurt, Cheese, saurekaurt kimchi fermented sausages etc. LAB were well known for its obligate fermentative nature. In fermentation bacteria used substrate level phosphorylation and generate 2 ATP from one glucose molecule. This fermentative production of ATP is not an efficient catabolic process as it only yields 2 ATPs per glucose molecule. Some LAB species have the ability to transform itself from fermentation to aerobic respiration in presence of heme and menaquinone. Lactobacillus sp is the best-reported LAB species capable of carrying aerobic respiration in rich medium (MRS) supplemented with heme and menaquinone, which results in increased cell number and enhanced stress tolerance capability. Thus induced aerobic respiration could be used as a potential technique for preparation of industrially important bacterial culture. The aim of this study was to isolation and characterization of aerobic respiratory Lactobacillus spp for higher cell number production. The pure 39 lactobacilli isolated from milk and plant based samples. Among of these isolates, 23 have been reported the ability of aerobic respiration. The highest difference in OD600 of 0.662 was reported in isolate Gjr. The study concluded that the utility of using aerobic respiration system for lactobacilli can be used for production of higher cell number of bacteria economically with very small amount of heme and menaquinone supplementation.