We obtained many aerobic cellulolytic microorganisms which were distinguished based on their colony morphology. Among them, a bacterial isolate JS-C42 exhibited highest lignocellulolytic effect. In this study,
we are presenting a detailed report of a yellow actinomycete Dabrafenib order isolate JS-C42. Plating of the cultures of JS-C42 on cellulose agar during subsequent sub culturing also depicted the extensive clearing zones. The clearing zone shown depicted the cellulose solubilization by extracellular enzymes produced by JS-C42 isolate and this result was in accordance with the cellulolytic studies as reported by Sizova et al. . Cellulolytic strain JS-C42 has a smooth surface, pale yellow, circular, opaque colonies and approximately 1.0 mm in diameter after 36 h growth at 28 °C on cellulose supplemented medium. It grew well at pH 7.5–9.0, 28–37 °C and up to 10% NaCl concentration. The cells were Gram-positive, non-motile cocci-shaped, have primary mycelium with no spore and exhibited aerobic growth. The bacterial isolate JS-C42 utilized the starch, casein, urea and lipid molecule such as tributyrin.
The utilization of starch, casein, mannitol salt agar, tributyrin, and urea showed that the isolate produced the extra cellular enzymes amylase, protease, lipase and urease to metabolize the polymeric components of the nutrient mixture to monomeric form for the growth. For predicting the Belnacasan phylogenetic position of the isolate JS-C42, the phylogenetic tree (Fig. 1) with its closely related type and non-type strains were analyzed using Ribosomal Database Project. The nucleotide sequence of the 16S rRNA gene of JS-C42 displayed 98.9% sequence identity to the available 16S rRNA gene sequence of the type strain Isoptericola halotolerans YIM 70177 Chloroambucil and 99.3% sequence similarity to the non type strain Isoptericola sp. DSX2. The closely related type strain Isoptericola halotolerans YIM 70177 was negative for milk peptonization and starch hydrolysis and its colonies are pale-yellow in color . When compared to the type strain Isoptericola halotolerans YIM 70177
and in spite of the 16S rRNA gene sequence identity of 98.9%, the cellulolytic bacterial isolate JS-C42 showed phenotypic differences in cell morphology like intense yellow with distinct mycelium and distinct biochemical properties like positive reaction for milk peptonization and starch hydrolysis. Overall the phylogenetic analysis of cellulolytic bacterial isolate JS-C42 revealed its belongings to the phylum Actinomyces and denoted as Isoptericola sp. JS-C42. The cellulose hydrolysis is observed after the 48 h incubation with a zone of the hydrolyzed region of the cellulosic agar medium flooded with Gram’s iodine, which produces a bluish-black complex with cellulose but not with hydrolyzed zone containing simple sugars .