抗生素对于对虾苗池水体细菌区系的影响

以细菌16S rDNA片段作为分子标记，采用PCR结合DGGE（Denaturing gradient gel electrophoresis）的方法构建了细菌区系指纹图谱，研究了对虾苗池使用硫酸链霉素、土霉素和氨苄青霉素3种抗生素后水体细菌区系的变化.结果表明：在120 h试验期内，与对照组相比，苗池水体分别经0.5 mg·L^-1的硫酸链霉素、土霉素和氨苄青霉素处理后，细菌区系均产生了显著变化；对照组水体0～30 h时段的细菌DGGE条带聚为一组，56～120 h取样时的条带聚为一组；而3个处理组水体0～56 h时段的细菌DGGE条带聚为一组，72～120 h聚为一组.对DGGE图谱典型条带进行测序，经BLAST-N比对，表明对虾苗池水体细菌多样性丰富，包括可培养的细菌（主要包括亚硫酸盐杆菌、红假单胞菌、美人鱼发光杆菌、聚球菌、海洋放线菌、黄杆菌、丝状光合细菌、粘细菌、哈氏弧菌）和某些不可培养的其他海洋细菌等.其中，单胞菌、发光杆菌、放线菌、黄杆菌、粘细菌和2种不可培养的其他海洋细菌不受抗生素的影响；而硫细菌、丝状光合细菌和另外8种不可培养的其他海洋细菌则因抗生素种类不同产生了不同的时空变化.

Effects of antibiotics on bacterial community in shrimp hatchery system

With bacterial 16S rRNA gene(rDNA)as molecular marker and by using PCR-DGGE technique,the fingerprints of bacterial community were constructed to study the effects of applying streptomyein sulfate,terramycin,and penicillin on the bacterial community in shrimp hatchery system.Within the 120 h experimental period,significant difference in the diversity of the bacterial community was observed between the treatments applied with 0.5 mg·L~(-1) of test antibiotics and the control.In the control,the band patterns in 0-30 h were clustered into one clade,and those in56-120 h were clustered into another; while in the treatments applied with test antibiotics,the band patterns in 0-56 h were clustered into one clade,and those in 72-120 h were clustered into another.After the sequencing of DGGE bands,the BLAST-N searches for sequence similarity showed great diversity of bacterial species,including culturable bacteria(mainly Sulfitobacter sp.,Rhodobacteraceae sp.,Photobacterium damselae,Synechoccoccus sp.,Actinomycetales,Flavobacteriaceae,Filamentous photosynthetic,Mucus,and Vibrio harveyi)and some uncultured marine bacteria,among which,Rhodobacteraceae sp.,Photobacterium damselae,Actinomycetales,Flavobacteriaceae,Mucus,and two unculturable bacteria were less affected by the three antibiotics,while Sulfitobacter sp.,Filamentous photosynthetic,and other eight unculturable marine bacteria changed in different spatiotemporal patterns with the kinds of test antibiotics.