Production of cellulase (Cx) by different species of Erwinia

Abstract

The tested isolates of Erwinia chrysanthemi (corn pathotype) and E. carotovora constitutively produce high levels of cellulase(s) (Cx) in presence or absence of carboxymethyl-cellulose (CMC) as substrate in the medium. The tested isolates of E. atroseptica produced high levels of cellulase when grown in presence of both carboxymethyl-cellulose (CMC) and sucrose, low levels in presence of carboxymethyl-cellulose alone, and traces of cellulase(s) in presence of sucrose alone. The activity of cellulase(s), present in culture supernatants of E. chrysanthemi (corn pathotype) and E. carotovora, occurred in a broad range of pH value (2.2--9) with an optimum pH ranging from pH 4 to 7. However, the activity of cellulase(s), present in culture supernatant of E. atroseptica, occurred in a narrow range of pH value (3--7) with an optimum of about pH 5.