Consecutive batch culture — A novel technique for the in vitro study of mixed microbial populations from the rumen

Abstract

Consecutive batch culture (CBC) is a novel in vitro technique which has been used to study the effect of various chemical additives (sugars, sugar alcohols and phenolic acids) on fermentation by mixed populations of rumen micro-organisms. Each CBC consists of a series of up to 12 batch cultures inoculated in sequence at 48- or 72-h intervals, with a microbial suspension originating from the previous cultures. The first culture in each CBC was inoculated with a microbial suspension from the rumen. By transferring a portion of the culture to fresh medium at regular intervals, a morphologically diverse population of micro-organisms with rumen-like fermentation characteristics was maintained on certain substrates (such as ryegrass hay). In this paper, results concerned with the development of CBC technique are presented, together with a discussion on the use of the technique in perturbation studies with rumen micro-organisms and in studies of other microbial communities.