Determination of growth kinetics of isolated consortia for biogas generation

Abstract

A significant demand of energy lies in the rural domestic sector where energy available from non-conventional sources may play an important role. Generation of biogas from cattle excreta, municipal wastes and other types of wastes are well established. Our present study deals with determination of the kinetic parameters taking carbohydrate, protein and fat as limiting substrate. The purpose of taking these particular substances as limiting substrates is that these constituents are the main contents of the substances used to generate biogas. The liquid medium of a running digester based on vegetable market wastes has been used as seed culture. Both acidogenic and methanogenic bacterial strains have been isolated from the broth. Growth kinetics of acidogenic bacteria have been determined using carbohydrate, protein and fat as limiting substrates. Kinetics of exponential growth of methanogenic bacteria using Volatile fatty acids and Long chain fatty acids as substrates has been worked out. In all cases, Monod type model has been observed to fit well with the experimental growth patterns.