Unveiling the potential of metal-tolerant fungi for efficient enzyme production

• Published in: Process biochemistry (1991) Vol. 49; no. 11; pp. 1858 - 1866
• Main Authors: Jain, Navin, Bhargava, Arpit, Sabat, Debabrat, Panwar, Jitendra
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2014
• Subjects: Alkaline protease; Aspergillus; Azocasein; Metal resistance; Protease assay; Secretory proteins; BCA; CBB; SDS; Metal resistance; DEAE cellulose; PAGE; EDTA; PVDF; Aspergillus; TCA; Azocasein; PMSF; Protease assay; GRAVY; NCBI; Secretory proteins; MALDI–TOF-MS; Alkaline protease
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2014.07.023

The present study first time reports the utilization of metal tolerant fungi as a potential source for efficient enzyme production. The purification and characterization of alkaline protease from an indigenous zinc-metal tolerant fungal isolate Aspergillus flavus NJP08 has been demonstrated. The specific activity of enzyme was determined as 89.1Umg−1 which is found to be the highest among the reported Aspergillus flavus isolates so far. The protease was purified 55.87 fold up to homogeneity and identified as “alkaline protease” with a molecular mass of 33kDa. The N-terminal sequence was GLTTQKSAPWGLG which showed high similarity with other reported proteases of genus Aspergillus. Physico-chemical characterization of enzyme revealed an estimated half-life of >20h with aliphatic and GRAVY index values of 79.65 and −0.161 respectively, depicting high thermo-stability and secretory nature of protease. The protease was active within the temperature range of 25–50°C with an optimum temperature of 50°C and was stable in the pH range of 6.0–11.0. The enzyme was activated by Ca2+ and Fe2+ ions, partially inhibited by Cu2+ ions and strongly inhibited by PMSF. High enzyme stability in presence of various detergents further strengthens enzyme applicability in industrial applications.