CMC-liquefying enzyme, a low molecular mass initial cellulose-decomposing cellulase responsible for fragmentation from Streptomyces sp. LX.

LX, newly isolated from soil, was shown to secrete a carboxylmethylcellulose (CMC)-liquefying enzyme that cleaves the CMC chains, releasing negligible reducing terminals. The new enzyme, named component C2, was purified to homogeneity by dialysation. It has a molecular mass of 9.8 kDa. The pH optimum of the enzyme activity is 6.4 and its temperature optimum is 50 degrees C. It retains full activity at pH 4-6.4 upon incubation at 50 degrees C for 30 min. The enzyme has significant fragmentation activity on filter paper despite the absence of weight loss, release of reducing sugars and depolymerization during incubation with filter paper. The one-electron oxidative reaction is shown not to participate in the fragmentation of filter paper by enzyme C2.