ABSTRACT
Although this chapter does not deal with thennophiles, it deals with the concept of the workshop covered by this publication; that is, the origin of genes in microorganisms and the transfer of them between microorganisms and also higher eukaryotes. Specifically, evidence will be discussed indicating that anaerobic fungi present in the intestines of herbivorous animals contain genes apparently originating from aerobic bacteria and fungi, anaerobic bacteria, and their animal hosts. Gene transfers between the anaerobic fungi as well as gene duplications within them have also occurred. In addition, several hydrolytic enzymes with different catalytic properties involved in degradation of plant materials including cellulose and hemicellulose have very conserved domains such as dockerins and cohesins functioning in protein-protein interaction and in binding cellulose.
