Screening of microbes for novel acid cutinases and cloning and expression of an acidic cutinase from Aspergillus niger CBS 513.88

: Nyyssölä A, Pihlajaniemi V, Järvinen R, Mikander S, Kontkanen H, Kruus K, Kallio H Buchert J

: 2013

: Enzyme and Microbial Technology

: Enz Microbiol Technol

: 4-5

: 52

: 4-5

: 272

: 278

: 7

: 0141-0229

DOI: https://doi.org/10.1016/j.enzmictec.2013.01.005

Isolates from gardening waste compost and 38 culture collection microbes were grown on agar plates at pH 4.0 with the cutinase model substrate polycaprolactone as a carbon source. The strains showing polycaprolactone hydrolysis were cultivated in liq. at acidic pH and the cultivations were monitored by assaying the p-nitrophenyl butyrate esterase activities. Culture supernatants of four strains were analyzed for the hydrolysis of tritiated apple cutin at different pHs. Highest amts. of radioactive hydrolysis products were detected at pHs below 5. The hydrolysis of apple cutin by the culture supernatants at acidic pH was further confirmed by GC-MS anal. of the hydrolysis products. On the basis of screening, the acidic cutinase from Aspergillus niger CBS 513.88 was chosen for heterogeneous prodn. in Pichia pastoris and for anal. of the effects of pH on activity and stability. The recombinant enzyme showed activity over a broad range of pHs with maximal activity between pH 5.0 and 6.5. Activity could be detected still at pH 3.5.