Penicillium oxalicum SAEM-51: a mutagenised strain for enhanced production of chitin deacetylase for bioconversion to chitosan

A novel chitin deacetylase (CDA) producing strain Penicillium oxalicum ITCC 6965 was isolated from residual materials of sea food processing industries. Strain following mutagenesis using ethidium bromide (EtBr) and microwave irradiation had resulted into a mutant P. oxalicum SAEM-51 having improved levels of chitin deacetylase (210.71 ± 1.65 U l−1) as compared to the wild type strain (108.26 ± 1.98 U l−1). Maximum enzyme production was achieved in submerged fermentation following 144 hours of incubation with notably improved productivity of 1.46 ± 0.82 U l−1 h−1 as compared to the wild type strain (0.75 ± 0.53 U l−1 h−1). Scanning electron micrographs of mutant and wild type strains had revealed distinct morphological features. Evaluation of kinetic parameters viz. Qs, Qp, Yp/x, Yp/s, qp, qs had denoted that strain P. oxalicum SAEM-51 is a hyper producer of chitin deacetylase. Glucose as compared to chitin or colloidal chitin had resulted in increased levels of enzyme production. However, replacement of glucose with chitinous substrates had prolonged the duration for enzyme production. The mutant strain had two pH optima that is 6.0 and 8.0 and had an optimum temperature of 30 °C for growth and enzyme production.