Enhanced PHB production and scale up studies using cheese whey in fed batch culture of Methylobacterium sp ZP24
Enhanced PHB production and scale up studies using cheese whey in fed batch culture of Methylobacterium sp ZP24
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DOI：
10.1016/j.biortech.2007.10.017
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发表时间：
2008-09-01
影响因子：
11.4
通讯作者：
Desai, A. J.
中科院分区：
文献类型：
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作者：
Nath, A.;Dixit, M.;Desai, A. J.
甲基杆菌ZP24从二糖如乳糖和蔗糖产生聚羟基丁酸酯（PHB）。由于甲基杆菌ZP24显示生长相关的PHB产生，因此使用具有不同浓度的乳糖和硫酸铵的间歇进料策略以达到更高的聚合物产率。通过这种间歇饲喂策略，获得了约1.5倍的PHB产量增加。通过限制发酵罐中的溶解氧（DO）水平，可以实现PHB产量进一步增加0.8倍。DO的降低被认为增加了TCA循环中乙酰辅酶A向PHB积累的通量。干酪乳清是一种乳制品废物，是可利用的糖和其他营养素的丰富来源，当在生物反应器中用作替代乳糖的主要底物时，导致PHB产量进一步增加2.5倍。共4.58倍的增长，在聚羟基丁酸的生产得到使用限制DO条件下与补充硫酸铵的加工奶酪乳清在补料分批培养的甲基杆菌属。ZP24。因此，目前的调查反映了开发一种廉价的生物路线生产绿色热塑性塑料的可能性。(C)2007爱思唯尔有限公司保留所有权利。
Methylobacterium sp. ZP24 produced polyhydroxybutyrate (PHB) from disaccharides like lactose and sucrose. As Methylobacterium sp. ZP24 showed growth associated PHB production, an intermittent feeding strategy having lactose and ammonium sulfate at varying concentration was used towards reaching higher yield of the polymer. About 1.5-fold increase in PHB production was obtained by this intermittent feeding strategy. Further increase in PHB production by 0.8-fold could be achieved by limiting the dissolved oxygen (DO) levels in the fermenter. The decreased DO is thought to increase flux of acetyl CO-A towards PHB accumulation over TCA cycle. Cheese whey, a dairy waste product and being a rich source of utilizable sugar and other nutrients, when used in the bioreactor as a main substrate replacing the lactose, led to further increase in the PHB production by 2.5-fold. A total of 4.58-fold increase in the PHB production was obtained using limiting DO conditions with processed cheese whey supplemented with ammonium sulfate in fed batch culture of Methylobacterium sp. ZP24. The present investigation therefore reflects on the possibility of developing a cheap biological route for production of green thermoplastics. (C) 2007 Elsevier Ltd. All rights reserved.