The objectives of the research in our laboratory have been to identify the pectinolytic enzymes secreted by bacteria and apply these towards the enhanced maceration and solubilization of plant material. We have focused on the pectate lyases secreted by the phytopathogenic strains of Erwinia chrysanthemi, the ruminant resident Lachnospira multiparus, and the wood digestor isolate, Clostridium populeti. An HPLC approach has been developed that permits the kinetic analysis of each enzyme with respect to the formation of individual products during the pectate depolymerization process. This approach has demonstrated that each of these organisms secretes a nonrandom trimer-generating pectate lyase with a combination of endolytic and exolytic depolymerizing mechanisms. Two different strains of E. chrysanthemi secrete a battery of pectate lyases that include random endolytic as well as nonrandom dimer- and nonrandom trimer-generating endolytic/exolytic mechanisms. Enzymes with each of these depolymerizing mechanisms have been produced in quantity in Escherichia coli following transformation with plasmids carrying the pelA, pelB, pelC, or pelE genes derived from E. chrysanthemi EC16. These enzymes and/or the bacteria which secrete them may be used to promote the solubilization of the pectate component of plant biomass as a prerequisite to the conversion to ethanol, methane, or other useful products.