• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>AMB Express >Effect of nitrogen availability on the poly-3-d-hydroxybutyrate accumulation by engineered Saccharomyces cerevisiae
【2h】

Effect of nitrogen availability on the poly-3-d-hydroxybutyrate accumulation by engineered Saccharomyces cerevisiae

机译：酿酒酵母对氮素有效利用对聚-3-d-羟基丁酸积累的影​​响

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Poly-3-d-hydroxybutyrate (or PHB) is a polyester which can be used in the production of biodegradable plastics from renewable resources. It is naturally produced by several bacteria as a response to nutrient starvation in the excess of a carbon source. The yeast Saccharomyces cerevisiae could be an alternative production host as it offers good inhibitor tolerance towards weak acids and phenolic compounds and does not depolymerize the produced PHB. As nitrogen limitation is known to boost the accumulation of PHB in bacteria, the present study aimed at investigating the effect of nitrogen availability on PHB accumulation in two recombinant S. cerevisiae strains harboring different xylose consuming and PHB producing pathways: TMB4443 expressing an NADPH-dependent acetoacetyl-CoA reductase and a wild-type S. stipitis XR with preferential use of NADPH and TMB4425 which expresses an NADH-dependent acetoacetyl-CoA reductase and a mutated XR with a balanced affinity for NADPH/NADH. TMB4443 accumulated most PHB under aerobic conditions and with glucose as sole carbon source, whereas the highest PHB concentrations were obtained with TMB4425 under anaerobic conditions and xylose as carbon source. In both cases, the highest PHB contents were obtained with high availability of nitrogen. The major impact of nitrogen availability was observed in TMB4425, where a 2.7-fold increase in PHB content was obtained. In contrast to what was observed in natural PHB-producing bacteria, nitrogen deficiency did not improve PHB accumulation in S. cerevisiae. Instead the excess available carbon from xylose was shunted into glycogen, indicating a significant gluconeogenic activity on xylose.
机译：聚-3-d-羟基丁酸酯（或PHB）是一种聚酯，可用于从可再生资源生产可生物降解的塑料。它是由几种细菌自然产生的，是对碳源过量时营养缺乏的响应。酿酒酵母可以作为替代宿主，因为它对弱酸和酚类化合物具有良好的抑制剂耐受性，并且不会解聚生成的PHB。由于已知氮限制会促进细菌中PHB的积累，因此本研究旨在调查氮利用量对两种具有不同木糖消耗途径和PHB产生途径的重组酿酒酵母菌株：表达NADPH依赖的TMB4443的PHB积累的影响。优先使用NADPH和TMB4425的乙酰乙酰基-CoA还原酶和野生型链球菌XR，其表达NADH依赖性乙酰乙酰基-CoA还原酶和突变的XR，对NADPH / NADH具有平衡的亲和力。 TMB4443在有氧条件下以葡萄糖为唯一碳源积累了最多的PHB，而在无氧条件下以木糖为碳源的TMB4425获得了最高的PHB浓度。在这两种情况下，均获得了最高的PHB含量和较高的氮利用率。在TMB4425中观察到氮利用率的主要影响，其中PHB含量增加了2.7倍。与在天然PHB产生细菌中观察到的相反，氮缺乏并不能改善酿酒酵母中PHB的积累。相反，来自木糖的过量可用碳被分流到糖原中，表明对木糖具有显着的糖原异生活性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号