一株油脂降解菌的筛选及其降解条件优化  

Screening of A Oil-degrading Strain and Optimization of Its Degradation Conditions

作　　者：王亚军[1] 蔡文娟 耿冲冲 王惠 张蓉 陈甜靖 李金守 WANG Yajun;CAI Wenjuan;GENG Chongchong;WANG Hui;ZHANG Rong;CHEN Tianjing;LI Jinshou(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Lanzhou Xingrong Environmental Development Co.,Ltd,Lanzhou 730070,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]兰州兴蓉环境发展有限责任公司,甘肃兰州730070

出　　处：《生态环境学报》2020年第5期1031-1038,共8页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(41967043);校企融合项目(lzxr-2019032)。

摘　　要：为实现生活污水中油脂的生物降解和有效处理,从某生活污水处理厂的剩余污泥中分离出一株油脂降解菌用于油脂生物降解的研究。对该菌进行生理生化特性鉴定、16S rDNA测序分析和系统发育树构建,结果显示该菌株与铜绿假单胞菌(Pseudomonas aeruginosa)具有很高的同源性。按6%(V/V)的接种量将该菌接种到以菜籽油(质量浓度为3 g·L^−1)为唯一碳源的培养基中,在30℃,150 r·min^−1的恒温振荡培养箱中进行培养,采用紫外分光光度法每隔12 h测定油脂浓度,对其降解特性进行初步研究并发现该菌在72 h内对油脂的降解率为55.37%。从接种量、pH、温度、NaCl质量浓度4个方面进行单因素培养条件优化实验,得到当接种量为12%(V/V)、pH为8、温度为30℃、NaCl质量浓度为2.5 g·L^−1时该菌对油脂的降解率分别为59.42%、61.28%、55.33%、64.14%。另外发现当接种量在2%—14%(V/V)、pH在4.0—9.0、温度在15—40℃、NaCl质量浓度在0—15 g·L^−1时,该菌对油脂仍有降解效果,说明该菌株对外界环境具有一定的适应能力。将该菌应用于处理实际污水中的有机物,发现在优化条件下该菌对实际污水中的油脂和CODCr的降解率分别为40.50%和45.83%。结果表明在实验过程中该菌对油脂和实际污水中的有机物都具有一定的降解效果,可以为下一阶段的实际应用奠定基础,并为生物处理含油污废水提供更多的菌种选择。In order to achieve the biodegradation and effective treatment of oil in domestic sewage,a oil-degrading strain was isolated from the remaining sludge of a sewage treatment plant for the study of oil biodegradation.The identification of physiological and biochemical characteristics,16S rDNA sequencing analysis and phylogenetic tree construction of the strain showed that the strain had high homology with Pseudomonas aeruginosa.Inoculating the strain into a medium with rapeseed oil(mass concentration is 3 g·L^−1)as the sole carbon source by 6%(V/V)inoculation volume and incubating at 30℃,150 r·min^−1 in a constant temperature shaking incubator,then using ultraviolet spectrophotometry to determine the oil concentration every 12 hours.Through a preliminary study of its degradation characteristics and found that the degradation rate of oil within 72 hours was 55.37%.Single factor cultivation conditions optimization experiments were conducted from four aspects:inoculation volume,pH,temperature,and NaCl mass concentration.It was obtained that the oil degradation rate was 59.42%,61.28%,55.33%,64.14% when the inoculation volume was 12%(V/V),the pH was 8,the temperature was 30℃,and the NaCl mass concentration was 2.5 g·L^−1.In addition,it was found that the strain still retained the degradation effect on oil when the inoculation volume was 2%-14%(V/V),the pH was 4.0-9.0,the temperature was 15-40℃and the NaCl mass concentration was 0-15 g·L^−1.This showed that the strain had a certain adaptability to the external environment.The strain was applied to handle the actual organic matter in sewage and found the degradation rates on the oil and CODCr were 40.50% and 45.83% respectively in the optimal conditions.These results showed that the strain had a certain degradation effect on the oil and the organic matter in the actual sewage during the experiment,which could lay the foundation for the practical application in the next stage and provide more strain species for biological treatment of oily wastewater.

关 键 词：铜绿假单胞菌 油脂降解 筛选分离 降解特性 

分 类 号：X172[环境科学与工程—环境科学]