海洋潮差区混凝土表面微生物16S rDNA分子鉴定

Microorganism identification by 16S rDNA of concrete surface exposed to a tidal zone

针对目前海洋混凝土工程的腐蚀现状,进行了海洋微生物对潮差区混凝土的作用机理及完善海工混凝土的腐蚀机理探索.通过海工混凝土潮差区部位取样,对暴露于潮差区中部22 y的混凝土试样表面进行FE-SEM、EDAX分析,结果表明:潮差区混凝土表面腐蚀严重,结构疏松,表面覆盖有有机物质和微生物.并将暴露于潮差区中部22 y的混凝土试样和该取样位置挂置7 d的混凝土试样表面的微生物群落分别分离,克隆了其中30株和12株细菌的16S rDNA基因,测定其序列且进行比对,其分别属于15个和7个种属中.优势种属均为假交替单胞菌,但随着暴露时间的增加,总细菌株数和总菌属数分别增大到2.5和2.14倍,且种属的变化也很大.同时,建立了海洋混凝土工程表面细菌鉴定方法,以及分离、鉴定的菌种为后续细菌对混凝土作用的试验提供菌种.

To minimize corrosion in marine concrete engineering,the effect of marine microorganisms on marine concrete engineering in the tidal zone was explored.Concrete specimens were drilled from marine concrete engineering exposed to tidal zones.The surfaces of concrete exposed to tidal zones for 22 years were analyzed by FE-SEM and EDAX.Results show that the surface of concrete exposed to tidal zones revealed severe corrosion and loose structure,and was covered with organic substances,microorganisms,and metabolites.The microbiologic population on the surface concrete specimens exposed to tidal zones for 22 years were taken,which were separated into two groups.One group was cloned for 30 bacteria immediately after taking from the tidal zone,another group was hung for 7 days first and then was cloned for 12 bacteria,with the 16S rDNA gene sequence,respectively.The two groups of bacteria were then measured and compared and classified into 15 and 7 genera,respectively.All the dominant genera are pseudoalteromonas.However,as the exposure time increased,the total bacteria and total genera rose respectively to 2.5 times and 2.14 times,and the genera have significant changes.In addition,a method was developed to identify marine engineering surface bacterium,providing bacteria to test how they affect concrete durability in future.