Isolation and characterization of a novel cellulolytic activity from a hot spring thermophilic alyciclobacillus sp.

A screening of thermophilic cellulolytic bacteria was carried out from samples collected in Sao Miguel hot springs, Azores islands. Among twenty four bacterial isolates which proved to be able to degrade cellulose, a strain assigned to Alicyclobacillus sp HS6-23, exhibited the highest extracellular cellulase activity (520 mU/mL). The enzymatic production was induced by carboxymethyl cellulose and reached its maximum in the late stationary phase. After a partial purification and characterization, the cellulolytic activity revealed its acidophilic and thermophilic properties. Optimal temperature was 65°C and the enzyme showed the highest activity in the range of pH 3.0-5.5 with the best performance at pH 4.0. These enzyme features encourage its further purification, cloning and characterization oriented to the biocatalyst application for several industrial purposes.