Method for the monitoring and control of microbial populations

Abstract

A method is disclosed for the monitoring and control of a microbial population in a biotechnological system. The method involves the identification of at least one critical subpopulation and determining the optimal level for said subpopulation. A controlled variable is determined which can be adjusted to alter the level of the subpopulation. The method employs nucleic acid hybridization in the microbial population. This involves the preparation of a labelled probe from nucleic acid having a nucleotide sequence substantially complementary to a nucleotide sequence in the nucleic acid in the subpopulation. A representative sample of the microbial population is obtained and treated to free nucleic acids and to denature double-stranded nucleic acids. The resulting sample nucleic acids are contacted with the labelled probe under appropriate conditions to form duplexes. The labelled probe in the duplex is monitored to determine the amount of duplexes and the level of the subpopulation is calculated from the determined duplexes. The controlled variable is adjusted based on the calculated level of the subpopulation to bring the level toward the optimal level. The method is used to monitor and control the microbial population without reliance upon the phenotypical expression of the genetic information of the organisms.