Studies On Screening Microorganisms Degrading Linear Sodium Alkylbenzenesulphonate(LAS) And Its Degrading Characteristics

The biodegradation research of linear alkyibenzenesulphonate(LAS) which is the most popular used anionic surfactants in the world by screening of efficient degrading bacteria is conducted and the influence of various physical and chemical factors on LAS degradation efficiency is investigated. After cultivation of the microorganisms from several different samples, a LAS degrading bacteria GZ6 which can use LAS as the sole carbon supply is founded and identified as Corynebacteria jeikeium GZ6 by American Biolog Microstation Identification System. The LAS degrading enzyme in bacteria GZ6 is identified as LAS induced-enzyme, so we use LAS as inducing chemical to acclimate the bacteria. The results showed that the LAS degrading abilities are greatly promoted from 50 mg/i d to 300 50 mg/I d after 9 ages? acclimation. The best environmental conditions for the growth and LAS degradation of bacteria GZ6 are 30拁C,pH7.0,shaking speed 300r/min. And temperature is the key factor of the three. LAS is not the priority carbon supply of bacteria GZ6. The LAS degradation will be impressed when there is other carbon supply easily to be used. And bacteria GZ6 can use organic nitrogen supply better than inorganic nitrogen supply. Heavy metal ions Cd2~ Hg2~~ Co2~. Cu2~. Zn2~ especially Hg2*, Cd2~. Co2~ can greatly restrain the growth and LAS degradation of bacteria GZ6. The effect experiment of LAS concentration shows that the best degradation efficiency is achieved at 400 mg/I of LAS concentration, and the COD decrease rate reaches up to 90%, which accomplish the goal of the subject. GZ6 is a LAS degrading bacteria with high capabilities and can be readily applied to the treatment of LAS manufacturing effluent especially through some biotreatment technology to enforce its degrading abilities.