脱色希瓦氏菌(Shewanella decolorationis) S12还原不同电子受体的厌氧发酵罐培养方法

The Method Study of Shewanella decolorationis S12 Reduce Different Electron Acceptors with Anaerobic Fermentor Culture

摘要:

脱色希瓦氏菌Shewanella decolorationis S12在厌氧环境下能够使用多种电子受体进行厌氧呼吸。为了取得足够的细胞量用于膜蛋白质组学等科学研究的需要, 本研究选取无机小分子(硝酸钠)、金属离子(柠檬酸铁)和有机大分子(偶氮染料苋菜红)作为电子受体, 在使用确定成分的无机盐培养基条件下, 使用不同浓度的电子供体和碳源对S12进行厌氧条件下静置和发酵罐的优化培养, 采用连续补充电子受体的培养方式, 确认了电子供体和碳源的合适浓度, 建立了S12厌氧发酵罐培养方法。相比传统的静置厌氧培养, 厌氧发酵罐培养方法在保证了严格厌氧条件下高效率还原电子受体的同时, 还极大的提高了细胞生长密度。连续补充电子受体的厌氧发酵罐培养的S12最大细胞密度最大分别可达到静置厌氧培养细胞密度的325, 304, 369倍, 而生长时间也比静置厌氧培养分别缩短了26.5%, 17.6%, 7.5%。这为需要大量细胞和蛋白的细菌厌氧呼吸生长实验建立了可行方法, 对于进行兼性厌氧呼吸的微生物的大规模厌氧培养具有借鉴意义。

Abstract:

Shewanella decolorationis S12 is a strain which can perform anaerobic respiration by using various electron acceptors under the anaerobic environment. In this study, to obtain the enough biomass and satisfy the need of scientific research such as membrane proteomics, we used the inorganic small molecule (sodium nitrate), metal ion (ferric citrate) and organic macromolecule (azo dye amaranth) as sole terminal electron acceptors, using different concentrations of electron donor and carbon source for anaerobic stationary culture and anaerobic fermentor culture of Shewanella decolorationis S12. The cells were cultured by fed-batch cultivation mode to confirm the optimal concentrations of electron donor and carbon source, finally the method of anaerobic fermentor culture for S12 was established. Comparing to the traditional anaerobic stationary culture method, anaerobic fermentor culture method not only ensured a high rate mass-transfer efficiency resulting in the effective reduction of electron acceptors, but also greatly increased the cell growth density, the max cell growth densities were increased to 325, 304, 369 times and cell growth times were decreased 26.5%, 17.6%, 7.5% separately. This method provided an effective way to culture a large number of cells and protein under anaerobic respiration condition. The procedure described above would be significance for the studies which need biomass cultivation of Shewanella genus bacteria and other anaerobic microorganisms under fully controlled conditions.