Isolation and identification of a bacterial strain capable of degrading butyl acetate

Abstract:

[Background] Esters are one of the common components in industrial waste gas. Using microorganisms for the degradation of esters has a promising application prospect and thus deserves research. [Objective] To study the degradation characteristics and pathway of a butyl acetate-degrading strain isolated from the activated sludge of a sewage treatment plant in Zhejiang Province. [Methods] This strain was identified based on the physiological, biochemical, and 16S rRNA gene sequence. The single factor experiments were carried out to analyze the degradation characteristics of the strain for butyl acetate, and the degradation intermediates were detected. [Results] The strain was identified as Acinetobacter modestus HYY-1. It demonstrated strong degradation effect on butyl acetate under alkaline conditions (pH 8.0–10.0). The strain showed high degradation efficiency for butyl acetate at 264.75–1 059.00 mg/L, which nearly reached 100% within 120 h in the case of the highest butyl acetate concentration. The initial inoculation concentration of the strain had little effect on the degradation efficiency, which reached 100% within 120 h in the case of different initial inoculation concentrations. The main intermediates in the degradation of butyl acetate by this strain were n-butanol and acetic acid, and the final products were CO₂ and bacteria biomass. The proportions of the products varied under different initial butyl acetate concentrations. [Conclusion] Strain HYY-1 has the ability to efficiently degrade butyl acetate. Specifically, the strain may degrade butyl acetate by ester bond hydrolases into n-butanol and acetic acid, which were ultimately mineralized into CO₂ and bacteria biomass. This study provides theoretical support for deciphering the biodegradation mechanism of butyl acetate and exploring the bioremediation path of butyl acetate-contaminated environment.