Fermentation Conditions and Properties of a Chitosanase fromAcinetobactersp. C-17

Abstract

A species of bacterium with high chitosanase activity was isolated from soil samples in Haiyan City, China, and identified as an Acinetobacter species. This strain, named Acinetobacter sp. strain C-17, produced a chitosanase that was inducible and secreted into the medium. The optimal conditions for enzyme production were cells used to inoculate a medium containing 1% chitosan (pH 7.0) followed by culture at 30 degrees C. The chitosanase activity reached 1.7 U/ml when strain C-17 was incubated in a 250-ml flask under the optimal conditions for 24 h, and reached 2.8 U/ml when cells were incubated in a 3-l fermentor. The optimal pH and temperature for hydrolysis of chitosanase were 7.0 and 36 degrees C, respectively. The chitosanase activity was stable in the pH range of 5-8 and temperature range of 30-40 degrees C. The chitosanase of the strain was extracted by zinc acetate and ammonium sulfate precipitation. The molecular mass was estimated to be 35.4 kDa by SDS-PAGE.

Statistical optimization of medium compositions for chitosanase production by a newly isolated Streptomyces albus

“…C-17 (Zhu et al, 2003) and Bacillus cereus D-11 (Gao et al, 2008). Peptone as a better nutrient source is needed by several microorganisms (Chen et al, 2009), but did not favor chitosanase production from S. albus YT2 in higher concentration.…”

“…RKY3 (63.53 U/mL) (Wee et al, 2009), Streptomyces griseus (0.92 U/mL) , Acinetobacter sp. C-17 (2.8 U/mL) (Zhu et al, 2003), Aspergillus sp (1.18 U/mL) (Li et al, 2008) and Matsuebacter chitosanotabidus (15.24 U/mL) (Park et al, 1999). Nevertheless, as far as we know, this constitutes the first report of chitosanase production by S. albus.…”

Biodegradation of shellfish wastes and production of chitosanases by a squid pen-assimilating bacterium, Acinetobacter calcoaceticus TKU024

“…Chitosanases have been found in abundance in a variety of bacteria (Chiang et al 2003;Gao et al 2008;Kurakake et al 2000;Zhu et al 2003). Almost all of the chitosanase-producing strains used colloidal chitosan or chitosan as a major carbon source, such as Acinetobacter sp.…”

“…Almost all of the chitosanase-producing strains used colloidal chitosan or chitosan as a major carbon source, such as Acinetobacter sp. C-17 (Zhu et al 2003), Bacillus cereus D-11 (Gao et al 2008), B. cereus S1 (Kurakake et al 2000) and Aspergillus sp. CJ22-326 (Chen et al 2005).…”

“…Reports about production of chitosanases by Acinetobacter species seem to be scarce (Zhu et al 2003). In this study, we attempted to optimize the culture conditions of A. calcoaceticus TKU024 for maximal chitosanase productivity by using cheap carbon/nitrogen source of squid pen powder.…”