Alkaline Cellulase Production by Penicillium mallochii LMB-HP37 Isolated from Soils of a Peruvian Rainforest

Abstract

Alkaline cellulases are demanded by the textile industry for several purposes but commercial preparations showing activity at alkaline conditions are very scarce. Aim: To characterize a Penicillium strain isolated form soils of a Peruvian rainforest showing alkaline cellulase activity that may be useful for the textile industry. Methodology: The molecular identification was based on the DNA sequence of its ITS region using ITS1 and ITS4 primers after PCR amplification. Cellulase production was evaluated in shaken flasks by using either lactose or microcrystalline cellulose. Total cellulase (as FPA) and endoglucanase activities were evaluated by the standard methods at several pH levels. Also, the cellulase activity of culture filtrates was tested for antipilling activity as compared to a commercial neutral cellulase preparation. Results: After raw data of ITS DNA sequence was processed, multiple alignment and phylogenetic analysis confirmed that our strain can be named as Penicillium mallochii LMB-HP37. Higher activity was attained for neutral total cellulase on lactose (3371±108 U/l at pH 7.4) and alkaline cellulases attained similar activity levels than the acid cellulase (2978±151 U/l at pH 8.4 and 2910±42 U/l at pH 9.4). FPA and endoglucanase activities were produced at high volumetric (46.8±1.5 and 13.5±1.0 U/l.h, respectively) and specific (32.9±1.1 and 9.5±0.7 U/gbiomass.h, respectively) productivities at the same pHs which indicate that this strain may be suitable for commercial development. The enzyme of P. mallochii LMB-HP37 had slightly better results than the commercial enzyme as an anti-pilling agent even though is a crude preparation. Conclusion: Penicillium mallochii LMB-HP37 produced high total cellulase activity on lactose which compares to well-known cellulase producers but at neutral to alkaline pH levels. Data obtained reveal that the crude enzyme is suitable for anti-pilling process (biopolishing) and may be also useful for biostoning.