采用原生质体融合技术选育提高氨氮降解效能的光合细菌  

The improvement of N-ammonia degradation of photosynthetic bacteria by protoplast fusion

作　　者：纪敦敦[1] 邱宏端[1] 谢航[1] 

机构地区：[1]福州大学生物科学与工程学院,福建福州350108

出　　处：《大连海洋大学学报》2011年第5期407-413,共7页Journal of Dalian Ocean University

摘　　要：将高效降解氨氮的假丝酵母菌Candida sp.与高效降解亚硝酸盐氮的耐盐红螺菌Rhodospeudomonas capsulate进行原生质体融合,探讨原生质体制备及融合的条件,并对融合子进行了筛选。结果表明,原生质体制备的优化条件如下:耐盐红螺菌,溶菌酶量为1.5 mg/mL,EDTA浓度为0.1 g/L,作用时间为45min;假丝酵母菌,蜗牛酶量为0.5 mg/mL,巯基乙醇的质量分数为0.1%,EDTA浓度为1 g/L,作用时间为30 min。两种原生质体在聚乙二醇(PEG-6000)和Ca2+的诱导下发生融合,在添加制霉菌素和链霉素的选择培养基上进行初筛,以生长稳定性及对氨氮、亚硝酸盐氮的降解效能等为指标进行复筛,获得了具有较好降解效能的融合子R1菌株。该菌株对亚硝酸盐氮的降解效能与耐盐红螺菌相同,达到90%以上;对氨氮的降解效能为63%,较耐盐红螺菌提高54%。A protoplast fusion was conducted between two efficient photosynthetic bacteria,N-ammonia degrading Candida sp.and N-nitrite degrading Rhodospeudomonas capsulate.The conditions of the protoplast formation and fusion were optimized,and the best fusant was selected.The better protoplast formation for Rhodospeudomonas capsulata was found under the conditions of： lysozyme at 1.5 mg/mL,EDTA 0.1 g/L and 45 min reaction time;for Candida sp.the better conditions of snail enzyme at 0.5 mg/mL,mercaptoethanol 0.1%,EDTA 1 g/L and 30 min reaction time.The fusion was induced by PEG 6000 and Ca2＋.Fusants were screened out by selective media containing added nystatin and streptomycin.The fusant R1 with better efficient degradation was selected by growth stability and degradation.The fusant R1 showed N-nitrite degradation at a rate of more than 90%,as good as for Rhodospeudomonas capsulata,but had N-ammonia degradation of only 63%,increased by 54%.

关 键 词：耐盐红螺菌 假丝酵母菌 氨氮降解 原生质体融合 

分 类 号：Q939.99[生物学—微生物学]