The influence of nutritional and environmental conditions on the accumulation of poly-β-hydroxybutyrate in Bacillus mycoides RLJ B-017
The influence of nutritional and environmental conditions on the accumulation of poly-β-hydroxybutyrate in Bacillus mycoides RLJ B-017
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DOI：
10.1046/j.1365-2672.2002.01590.x
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发表时间：
2002-01-01
影响因子：
4
通讯作者：
Nigam, JN
中科院分区：
文献类型：
--
作者：
Borah, B;Thakur, PS;Nigam, JN
目的：为优化蕈状芽孢杆菌RLJ B-017的生长和聚β-羟基丁酸酯（poly-beta-hydroxybutyrate，PHB）积累的营养和环境条件。真菌，生长在不同的碳源和氮源。其中蔗糖、牛肉膏和硫酸二铵最有利于菌体的生长和积累。细胞中的PHB（%）、PHB产率（Y-p/s）和生产率（Q（p）和q（p））的总体最大值为69.4 +/- 0.4%干细胞重量（DCW）、0.21 g（p）g（s）（-1）、0.104 +/- 0.012 g（p）l（-1）h（-1）和0.03 g（p）g（x）（-1）h（-1），当在含有20 g（s）l（-1）蔗糖并补充有硫酸二铵的培养基中生长时，添加牛肉膏使细胞中的PHB（%）值、PHB产量和生产率分别增加17.58 ± 0.3，23.8，19.23 ± 0.3和13.8 ± 0.2%。在pH7.0 ± 0.1、温度30 ± 0.5 ℃、搅拌速度650转/分（-1）和氧转移速率下，细胞的生长和积累均得到最大值。结论：蔗糖、葡萄糖和果糖更适合细胞生长和积累，但蔗糖比葡萄糖便宜。在氮源中，牛肉膏和硫酸二铵促进了PHB的合成。聚羟基丁酸酯的积累被观察到是增长associated.Significance和影响的研究：革兰氏阳性菌还没有被报道积累大量的聚羟基链烷酸酯，因此还没有被认为是工业生产的有效候选人。一些芽孢杆菌属。据报道，累积了9-44.5%的DCW PHB。相比之下，芽孢杆菌RLJ B-017含有69.4 +/- 0.4%的DCW PH B。因此，该菌株被认为是具有工业价值的有效生物体。在该野生菌株中获得了相对较高的PHB产量，并且PHB合成不受营养限制。在下一阶段采用补料分批培养，将优化获得更高的PHB产量和生产力的条件。
Aims: To optimize the nutritional and environmental conditions for growth of and poly-beta-hydroxybutyrate (PHB) accumulation in Bacillus mycoides RLJ B-017.Methods and Results: An isolate, identified as B. mycoides, was grown on different sources of carbon and nitrogen. Among these, sucrose, beef extract and di-ammonium sulphate were found to be the most suitable for growth and PHB accumulation. The overall maximum value of PHB (%) in cells, PHB yield (Y-p/s) and productivities (Q(p) and q(p)) were 69.4 +/- 0.4% dry cell weight (DCW), 0.21 g(p) g(s)(-1), 0.104 +/- 0.012 g(p) l(-1) h(-1) and 0.03 g(p) g(x)(-1) h(-1), respectively when grown in a medium containing 20 g(s) l(-1) sucrose, supplemented with di-ammonium sulphate. The addition of beef extract increased the value of PHB (%) in cells, PHB yield and productivities by 17.58 +/- 0.3, 23.8, 19.23 +/- 0.3 and 13.8 +/- 0.2%, respectively. The overall maximum values of PHB (% DCW), PHB yield and productivities were obtained at pH 7.0 +/- 0.1, temperature 30 +/- 0.5degreesC, agitation 650 rev min(-1) and oxygen transfer rateConclusions: Sucrose, glucose and fructose were found to be more suitable for cell growth and PHB accumulation, but sucrose was less expensive than glucose. Among the nitrogen sources, beef extract and di-ammonium sulphate promoted PHB synthesis. The accumulation of PHB was observed to be growth associated.Significance and Impact of the Study: Gram-positive bacteria have not been reported to accumulate large amounts of polyhydroxyalkanoate and hence have not been considered as potent candidates for industrial production. A number of Bacillus spp. have been reported to accumulate 9-44.5% DCW PHB. By comparison, Bacillus RLJ B-017 contained 69.4 +/- 0.4% DCW PHB. Therefore, this strain has been considered as a potent organism for industrial interest. A relatively high yield of PHB was obtained in this wild strain and PHB synthesis was independent of nutrient limitation. The conditions for the higher PHB yield and productivity will be optimized in the next phase using fed-batch culture.