摘要
采用液体富集培养的方法,从唐山污水处理厂附近植物根际土中分离得到一株苯酚降解菌11-256,对菌株进行了鉴定及苯酚降解试验。结果表明,菌株可以在以苯酚为唯一碳源和能源的无机盐培养基中生长,能够耐受最高质量浓度为2000mg/L的苯酚。该菌株为革兰阳性菌,呈短杆状、长杆状或球形,在ISP2培养基上形成圆形隆起菌落,菌落颜色由乳白到黄白色,在马铃薯浸汁和察氏琼脂培养基上产生可溶性浅黄色色素。菌株生长的温度范围为20-40℃,pH值范围为5.0-10.0,不能利用乳糖和甘油,能利用色氨酸为氮源,硝酸盐还原阳性,明胶液化阴性,H2S产生阴性。结合菌株16S rRNA基因序列同源性分析结果,鉴定菌株11-256为纤维化纤维菌（Cellulosimi-crobium cellulans）。在温度为28-32℃,pH值为6.5-8.5时,菌株对初始质量浓度500-1 500 mg/L的苯酚均能有效降解。研究表明,该菌株具有较强的环境适应能力和苯酚降解能力。
The aim of this paper is to isolate and characterize a strain capable of high-phenol-tolerance so as to determine the influential factors of phenol biodegradation.For this purpose,we have isolated a strain（11-256） of this nature from the rhizosphere soil in a sewage-treatment plant nearby Tangshan by using the liquid culture enrichment and plate spreading method.The strain can grow on the phenol as the sole carbon and energy source with its highest endurance capacity being 2 000 mg/L.Through our investigation,we have made clear the influential factors affecting the phenol degradation and the ideal phenol degrading rate,which tends to occur at pH 6.5-8.5,28-32 ℃,with the concentration of 500-1 500 mg/L phenol as the substrate.And,what the isolated was a facultative anaerobe,which had a gram-positive cellwall profile.The cells were rod-shaped,coryneform or coccoid and non-spore-forming.They would grow up into some spherical,round colonies on the culture base of ISP2,whose color comes from creamy white to buff,and tends to appear on the potato extract agar and czapeks agar media diffusible pigments.The temperature needed for the cell growth turned out to be from 20-to-40 ℃,rather than 45 ℃,but as a result of our study,the optimal temperature should be 30 ℃.The investigation also told us that the growth occurs at the pH value from 5.0 to 10.0,though the optimal pH for the growth should be 6.5-8.5.Beside,what can be degraded may include glucose,fructose,dulcite,galactose,mannose,cellobiose,arabinose,mannitol and tryptophane,with the exception of lactose and glycerine.We have also found that it was possible for the nitrate to be reduced,but impossible for H2S and gelatin to get degraded.Our phylogenetic analyses based on 16S rRNA gene sequence prove that the strain named 11-256 was most closely affiliated to the genus of Cellulosimicrobium,which likes to cluster with Cellulosimicrobium cellulans and Cellulosimicrobium funkei.While 16S rRNA gene sequential closeness between strain 11-256 and the strains of Cellulosimicrobium cellulans was found to be 99%,the DNA-DNA relatedness data and the phenotypic properties demonstrate that the strain 11-256 can be identified as Cellulosimicrobium cellulans.Thus,it can be seen that the strain under discussion is highly promising for its application prospect for its powerful capability to environment adaption and phenol degradation.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第3期24-28,共5页
Journal of Safety and Environment
基金
河北省教育厅自然科学研究计划项目(2009466)
关键词
环境工程学
苯酚
生物降解
纤维菌属
分离
鉴定
environmental engineering
phenol
biodegradation
Cellulosimicrobium
separation
identification
