Isolation,identification and characterization of a cold-adapted cellulase-producing psychrotrophic Streptomyces sp.

In this article,a cold-adapted cellulase-producing actinomycete,named ND2-1,was isolated form soil collected in Daqing Trench of Inner Mongolia. The morphological characteristics and 16 S r DNA sequence analysis showed that ND2-1 belongs to Streptomyces sp.. ND2-1 could grow at 10 ~35 ℃ and its optimum growth temperature was 25 ℃,indicating that it was a psychrotrophic bacterium. ND2-1 could disintegrate filter paper efficiently. The measured cellulase activity was the highest when 2 g/L of carboxymethylcellulose sodium(CMC-Na) was contained in the medium after cultivated at 25 ℃ for 3 days. The cellulase produced by ND2-1 was stable through p H3.0 ~9.0,the optimum reaction p H of the enzymewas 7.0,and the optimum reaction temperature was 30 ℃. K+and Cu2+could cause the inhibition of the enzyme activity. Mn2+improved the relative enzyme activity to 166.7%.