The effect of temperature and pH on psychrophilic chitinase expression in Pichia pastoris X-33

Abstract

To confirm the optimal cultivation conditions of Pichia pastoris X-33 containing the psychrophilic chitinase gene cloned from Antarctic microorganism, Sanguibacter antarcticus KOPRI 21702, the effect of temperature and pH on chitinase expression was investigated in a jar fermentor. Expression of target protein was performed by methanol addition and confirmed by an activity assay with p-nitrophenyl-N-acetyl-&#61538

-D-glucosaminide as a substrate. Cells were grown at various temperatures ranging from 20 to 30 &#61616

C and pHs from 5.5 to 6.5. The chitinase production was divided into two phases: batch and induction fed-batch. Ultimately, the optimal temperature and pH for the production of chitinase were found to be 20 &#61616

C, pH 6.0, respectively.