一株耐盐产电菌Shewanella algae E-1的分离及其产电特性分析

Isolation and characterization of a salt-tolerant exoelectrogenic strain Shewanella algae E-1

摘要:

【背景】产电微生物的种类和电化学活性机制对微生物燃料电池的产电性能有着重要的影响。【目的】从海水中分离获得一株耐盐产电微生物，研究其产电特性并鉴定种属信息。【方法】以取自南海的海水为接种液启动并运行阳极液中含有不同盐浓度的微生物燃料电池，从富集的阳极生物膜上分离得到一株纯培养的微生物菌株，命名为E-1。通过接种于阳极液中添加不同盐浓度的微生物燃料电池中对其产电特性进行分析，并利用形态学观察、Biolog分析和16S rRNA基因序列比对相结合的方法进行种属鉴定。【结果】菌株E-1在无外源添加和外源添加6.6% NaCl条件下产生的功率密度分别为51.69 mW/m2和26.56 mW/m2，这与其良好的耐盐能力相关。菌株E-1被鉴定为海藻希瓦氏菌(Shewanella algae)，表现出多样的底物利用能力，生长的温度范围为25?40 °C，pH范围为5.0?10.0。【结论】这是首次对Shewanella algae种内微生物产电性能及其在微生物燃料电池中应用的报道，丰富了产电微生物的多样性，菌株E-1能够在较高盐浓度条件下表现出良好的产电性能，为微生物燃料电池在海水资源化处理方面的应用提供新的实验材料。

关键词:海藻希瓦氏菌，微生物燃料电池，产电性能，耐盐能力，产电微生物

Abstract:

[Background] The types and electrochemical activity mechanism of exoelectrogenic microorganisms have important influence on the electrogenic performance of microbial fuel cells. [Objective] A salt-tolerant exoelectrogenic strain was isolated from seawater, its exoelectrogenic characteristic was studied and the species information was identified. [Methods] A pure exoelectrogenic bacterium (designated as E-1) was isolated from the enriched anodic biofilm of microbial fuel cells (MFCs), where the seawater from the south sea in China was used as the inoculum and MFCs were operated in the anolytes without and with salt addition. The exoelectrogenic characteristic of the pure isolate strain E-1 was investigated by inoculating into MFCs containing different salt concentrations. The species information was identified using the combined methods of morphological observation, Biolog analysis and 16S rRNA gene sequence alignment. [Results] The power densities of strain E-1 were respectively 51.69 mW/m2 and 26.56 mW/m2 without salt addition and with addition of 6.6% NaCl, which was related to its good salt tolerance. The strain E-1 was identified as Shewanella algae, which showed diversity in substrate utilization, and its growth temperature and pH range were 25?40 °C and 5.0?10.0, respectively. [Conclusion] The strain affiliated to S. algae is firstly reported to show electricity activity when applying in MFCs, which enriches the diversity of electricigens. S. algae E-1 can generate electricity at high salt concentration, which provides a new experimental material for the application of MFCs in seawater resourceful treatment.

Key words:Shewanella algae, Microbial fuel cells, Electricity production, Salt tolerance, Electricigens