Identification and characterization of a novel bacterial carbohydrate esterase from the bacterium Pantoea ananatis Sd-1 with potential for degradation of lignocellulose and pesticides.

Objective: Identification and characterization of a novel bacterial carbohydrate esterase (PaCes7) with application potential for lignocellulose and pesticide degradation. Results: PaCes7 was identified from the lignocellulolytic bacterium, Pantoea ananatis Sd-1 as a new carbohydrate esterase. Recombinant PaCes7 heterologously expressed in Escherichia coli showed a clear preference for esters with short-chain fatty acids and exhibited maximum activity towards α-naphthol acetate at 37 °C and pH 7.5. Purified PaCes7 exhibited its catalytic activity under mesophilic conditions and retained more than 40% activity below 30 °C. It displayed a relatively wide pH stability from pH 6–11. Furthermore, the enzyme was strongly resistant to Mg²⁺, Pb²⁺, and Co²⁺ and activated by K⁺ and Ca²⁺. Both P. ananatis Sd-1 and PaCes7 could degrade the pesticide carbaryl. Additionally, PaCes7 was shown to work in combination with cellulase and/or xylanase in rice straw degradation. Conclusions: The data suggest that PaCes7 possesses promising biotechnological potential. [ABSTRACT FROM AUTHOR]