A novel low temperature chitinase from the marine fungus Plectosphaerella sp. strain MF-1

✍ Scribed by Velmurugan, Natarajan (author);Kalpana, Duraisamy (author);Han, Jung Hoon (author);Cha, Hyo Jung (author);Lee, Yang Soo (author)

• Book ID: 118159122
• Publisher: Walter de Gruyter GmbH & Co. KG
• Year: 2011
• Tongue: English
• Weight: 322 KB
• Volume: 54
• Category: Article
• ISSN: 0006-8055
• DOI: 10.1515/bot.2010.068

✦ Synopsis

The marine fungus Plectosphaerella sp. strain MF-1 was isolated from sea shells and found to produce a chitinase potentially active at low temperature. The fungal strain was characterized by morphological and molecular features. Chitinase production by Plectosphaerella MF-1 was detected by inoculating the fungus into M9 medium containing 0.5% colloidal chitin at 108C. Crude chitinase production in culture filtrates reached a maximum 14 days after inoculation. Crude chitinase was purified by ammonium sulfate fractionation, cellulose DEAE anion exchange, and sephadex gel filtration chromatography. Purified marine fungal chitinase had activity at 378C, the difference in chitinase activities at 108C and 378C was less than 0.01 U ml -1 indicating chitinase was active at low temperature. The optimal pH for the low temperature active chitinase was 3-4. The K m was 0.03 mM and V max was 0.095, using p-nitrophenyl N-acetyl-b-D-glucosaminide as a substrate. Among the metal ions tested for inhibitory activity, Ag q , Hg 2q , and Pb 2q strongly inhibited enzyme activity, whereas Mg 2q and Fe 2q had minimal inhibition. The molecular mass of purified chitinase was determined as 67 kDa by SDS-PAGE. The N-terminal amino acid sequence was determined to be ''DNISQTGEHARYXPMVWFIKL''.