Studies on carboxymethyl cellulase produced by an alkalothermophilic actinomycete

A novel alkalothermophilic actinomycete having optimum growth at pH 9 and 50°C was isolated from self-heating compost from the Barabanki district of Uttar Pradesh, India. Based on its morphology, susceptibility of spores to heat and novobiocin, guanine± cytosine content of chromosomal DNA and cell wall composition, the organism was classi®ed under Thermomonospora. The alkalothermophilic actinomycete produced 23 IU/ml carboxymethyl cellulase (CMCase). The CMCase was puri®ed by fractional ammonium sulphate precipitation followed by cellulose anity chromatography and Sephacryl S-200 gel ®ltration. The CMCase had a molecular weight of 38 KD and pI of 4.1. The enzyme exhibited optimum activity at pH 5 and temperature 50°C. The CMCase showed pH stability in the range 7±10. The enzyme retained 100% activity at 50°C for 72 h and had half-lives of 7 and 3 h at 60°C and 70°C, respectively. The CMCase was stable in the presence of commercial detergents such as Ariel, Henko and Surf Excel, indicating its potential as an additive to laundry detergents.