Screening of a high-level chitinase producing strain, Paenibacillus barengoltzii and optimization of its fermentation conditions

Abstract:

[Objective] To identify a chitinase producing marine bacterium CAU904 isolated from China Nan Hai and optimize the fermentation conditions for chitinase production. [Methods] Strain CAU904 was identified based on its morphological characters and 16S rDNA sequence. The fermentation conditions for chitinase production by strain CAU94 were optimized using the one-factor-at-a-time method. [Results] The strain CAU904 was identified as Paenibacillus barengoltzii, and the optimal fermentation conditions were obtained as follows: 0.5% colloidal chitin, 0.2% yeast extract, 0.1% Tween 80 (medium pH 7.0) 45 °C for 72 h. Under the optimized fermentation conditions, the highest chitinase activity of 8.2 U/mL was achieved, which was 5.4 folds higher than that obtained before. The chitinase zymogram analysis showed that at least 11 chitinases were secreted into the fermentation broth, and three major bands had molecular masses of 54, 47 and 38 kD, respectively. [Conclusion] The results can be helpful for further study on the purification and application of the chitinases from Paenibacillus barengoltzii.