| 摘要: |
| 以龙须菜为唯一的营养源对深海沉积物进行富集和筛选，获得一个可降解龙须菜（Gracilaria lemaneiformis）、紫菜（Porphyra umbilicalis）和海带（Laminaria japonica）产生还原性寡糖的菌群.通过16S rRNA序列及16S rRNA-RFLP分析对该菌群中的细菌多样性进行了研究.结果表明，降解菌群中的细菌组成主要为弧菌属（Vibrio，8株）、火色杆菌属（Flammeovirga，7株）和希瓦氏菌属（Shewanella，5株），其中希瓦氏菌属和火色杆菌属的细菌在菌群中的丰度较高.采用龙须菜为唯一营养源的筛选培养基对菌群中的细菌进行分离，获得4株具有琼胶酶活力的细菌，包括2株火色杆菌属和2株希瓦氏菌属细菌.培养和未培养的结果均表明火色杆菌和希瓦氏菌这2个属为所研究的深海沉积物主要的龙须菜降解菌.对原始降解菌群和所分离的关键菌株进行了龙须菜酶解产糖能力的比较，结果发现菌群中的弧菌属菌株虽然自身没有酶解龙须菜的能力，但可能可以协助关键菌株，提高菌群对龙须菜的降解效率.因此本研究中所获得的菌群和菌株有望在琼胶寡糖的绿色生产中得到广泛应用. |
| 关键词: 海洋生物学 深海 龙须菜 降解 菌群 多样性 火色杆菌 希瓦氏菌 |
| DOI：10.3969/J.ISSN.2095-4972.2016.02.001 |
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| 基金项目:海洋公益性行业科研专项资助项目（201505026）；厦门南方海洋中心资助项目（13GZP003NF09）；福建省科技计划重点资助项目（2012Y0071） |
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| Screening，identification and diversity analysis of Gracilaria lemaneiformis-degrading flora from deep-sea sediments |
| DING Zhixin,CHEN Xinglin,ZHOU Zhidong,JIN Min,ZENG Runying |
| (Zhejiang SciTech University，Hangzhou 310018，China;State Key Laboratory Breeding Base of Marine Genetic Resources，Third Institute of Oceanograpiy, SOA,Xiamen 361005，China;Fujian Institute of Oceanography， Xiamen 361005，China;South China Sea BioResource Exploitation and Utilization Collaborative Innovation Center，Guangzhou 510300，China) |
| Abstract: |
| A bacteria flora that could directly degrade several algas including Gracilaria lemaneiformis， laver and kelp was isolated from deep-sea sediments of the west Pacific Ocean using Gracilaria lemaneiformis as solo nutrition for enrichment. 16S rRNA sequencing and 16S rRNA-RFLP analysis were carried out to investigate the bacterial diversity of Gracilaria lemaneiformis-degrading flora. The results showed that flora was mainly comprised of Vibrio （8 strains）， Flammeovirga（7 strains） and Shewanella（5 strains）. After the separation of original flora， 4 strains including 2 Flammeovirga and 2 Shewanella strains were found to possess the ability of Gracilaria lemaneiformis degradation. Thus， both uncultured and cultured analysis performed in our study suggested that Flammeovirga and Shewanella were the key strains responsible for algal degradation. Furthermore， comparison of Gracilaria lemaneiformis-degrading activity between original flora and isolated key strains showed that the Vibrio may help to improve the activity of flora despite of the lack of alga-degrading ability. Therefore， the present novel Gracilaria lemaneiformis-degrading flora and strains may be widely applied in production of oligosaccharide from Gracilaria lemaneiformis in the future． |
| Key words: marine biology deep-sea Gracilaria lemaneiformis degradation flora diversity Flammeovirga Shewanella |
