Polymer production by two newly isolated extremely halophilic archaea:: application of a novel corrosion-resistant bioreactor
Polymer production by two newly isolated extremely halophilic archaea:: application of a novel corrosion-resistant bioreactor
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DOI：
10.1007/s002530000394
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发表时间：
2000-09-01
影响因子：
5
通讯作者：
Steinbüchel, A
中科院分区：
文献类型：
--
作者：
Hezayen, FF;Rehm, BHA;Steinbüchel, A
构建了由聚醚酮（PEEK）、科技玻璃和亚硝酸硅陶瓷组成的新型耐腐蚀生物反应器，并将其用于培养两种新分离的极嗜盐古菌，分别产生聚γ -谷氨酸（PGA）和聚β -羟基丁酸（PHB）。这些细菌是从靠近阿斯旺（埃及）的高盐土壤中分离出来的。分离菌株40是Natrialba属的菌株，在固体培养基上培养时产生了大量的PCA。采用耐腐蚀生物反应器对培养条件进行优化。PGA的生成与NaCl浓度有关，在NaCl浓度为20% （w/v）时发生。在以蛋白酶-蛋白胨为培养基的间歇发酵过程中，对生物反应器进行搅拌和曝气，最大细胞密度约为1.6 g凝胶干物质/l。监测上清液中PGA的形成情况，90 h后，高效液相色谱法检测到最大培养量为470 mg/l。对菌株56的培养条件进行了优化，菌株56以胞内颗粒形式积累PHB。以乙酸和正丁酸为碳源，在搅拌曝气生物反应器中分批发酵，细胞密度为2.28 g细胞干物质/l， PHB积累量最大，约占细胞干重的53%。从菌株56的10.6 g干燥细胞中分离到约4.6 g PHB，其重量平均摩尔质量为2.3 × 10(5) g mol(-1)，多分散性约为1.4。
A novel corrosion-resistant bioreactor composed of polyetherether ketone (PEEK), tech glass and silicium nitrite ceramics was constructed and applied for the cultivation of two newly isolated, extremely halophilic archaea producing poly(gamma-glutamic acid) (PGA), or poly(beta-hydroxy butyric acid) (PHB), respectively. These bacteria were isolated from hypersaline soil close to Aswan (Egypt). The isolate strain 40, which is related to the genus Natrialba, produced large amounts of PCA when cultivated on solid medium. Culture conditions were optimised applying the corrosion-resistant bioreactor. PGA production was dependent on NaCl concentration and occurred about at 20% (w/v) NaCl in the medium. A maximum cell density of about 1.6 g Gell dry matter/l was obtained when the bioreactor was stirred and aerated in a batch fermentation process using proteose-peptone medium. The supernatant was monitored with respect to PGA formation, and after 90 h a maximum of 470 mg/l culture volume was detected by HPLC analysis. Culture conditions were optimized for the isolate 56, which accumulated PHB as intracellular granules. Batch fermentations in the stirred and aerated bioreactor applying acetate and n-butyric acid as carbon sources led to cell density of 2.28 g cell dry matter/l and a maximum PHB accumulation contributing to about 53% of cellular dry weight. About 4.6 g PHB were isolated from 10.6 g dried cells of strain 56, which exhibited a weight average molar mass of 2.3 x 10(5) g mol(-1) and a polydispersity of about 1.4.