Rachanamol RS, Lipton AP, Thankamani V, Sarika AR and Selvin J
The marine sponge Callyspongia diffusa associated bacterium produced protease enzyme which effectively inhibited the human pathogen S. aureus and fish pathogens viz., V. fluvialis, V. anguillarum, V. vulnificus and E. cloacae. The species identity of Bacillus subtilis VCDA (GenBank Accession No. KJ789102) was confirmed by 16S rRNA gene sequencing. The maximum protease activity was noted at 30°C and at pH 9. Protease production was stimulated in the presence of glucose (1.5%), tryptone (1.5%), NaCl (1.5%) and metal ions Ca2+ (1 mM) and Fe2+ (10 mM). The 46 K Da Bacillus subtilis VCDA protease was partially purified by ammonium sulphate precipitation and Sephadex G-100 column.