Poly-3-hydroxybutyrate production by Azotobacter vinelandii strains in batch cultures at different oxygen transfer rates
Poly-3-hydroxybutyrate production by Azotobacter vinelandii strains in batch cultures at different oxygen transfer rates
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DOI：
10.1002/jctb.4684
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发表时间：
2016-04-01
影响因子：
3.4
通讯作者：
Pena, Carlos
中科院分区：
文献类型：
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作者：
Diaz-Barrera, Alvaro;Andler, Rodrigo;Pena, Carlos
背景聚-3-羟基丁酸酯(PHB)是一种可由棕色固氮菌积累的聚酯。该聚合物是一种可生物降解的热塑性材料，用于生产包装塑料、生物基膜和生物相容植入物。结果在不同搅拌速度下，对野生型白色念珠菌和突变株OP产生的SPHB进行了评价。在300、400、500和600rpm的培养条件下，氧转移速率(OTR)的演变特征首次显示了突变型OP在培养物中的氧转移速率的演变。在评估的条件下，培养物受到氧气的限制。在与OP菌株一起生长的培养中，获得了较低的OTR和比耗氧速率，这表明该突变株对氧气的需求较低。通过降低OTR可以产生更多的PHB。在野生型菌株的培养中，PHB的最大干重为79%，而在600rpm的黑曲霉培养中，PHB的产量最高(0.18g L-1h(-1))。结论在氧气限制期间，PHB的产量可以由OTR控制，这为评估这一参数作为放大黑曲霉生产PHB的标准提供了可能性。(C)2015年化学工业学会
BACKGROUNDPoly-3-hydroxybutyrate (PHB) is a polyester that can be accumulated by Azotobacter vinelandii. This polymer is a biodegradable thermoplastic material used for producing plastics for packaging, biobased films, and biocompatible implants.RESULTSPHB produced by wild-type A. vinelandii and a mutant OP strain were evaluated at different agitation rates. The oxygen transfer rate (OTR) evolution was characterized in cultures grown at 300, 400, 500 and 600 rpm, showing for the first time the OTR evolution in cultures of mutant OP. Under the conditions evaluated, the cultures were limited by oxygen. In the cultures grown with the OP strain, lower OTR and specific oxygen uptake rate were obtained, indicating a lower necessity for oxygen for growth in this mutant. A higher amount of PHB can be produced by decreasing the OTR. A maximum PHB of 79% on dry weight was observed in the cultures with the wild-type strain, whereas the highest PHB productivity (0.18 g L-1 h(-1)) was obtained in cultures of A. vinelandiiOP conducted at 600 rpm.CONCLUSIONThe amount of PHB produced during the period of oxygen limitation can be controlled by the OTR, opening the possibility to evaluate this parameter as a criterion for scaling-up PHB production by A. vinelandii. (c) 2015 Society of Chemical Industry