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Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa

BACKGROUND: Polyketides, such as spinosad, are mainly synthesized in the stationary phase of the fermentation. The synthesis of these compounds requires many primary metabolites, such as acetyl-CoA, propinyl-CoA, NADPH, and succinyl-CoA. Their synthesis is also significantly influenced by NADH/NAD(+...

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Autores principales: Zhang, Xiangmei, Xue, Chaoyou, Zhao, Fanglong, Li, Dashuai, Yin, Jing, Zhang, Chuanbo, Caiyin, Qinggele, Lu, Wenyu
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4172946/
https://www.ncbi.nlm.nih.gov/pubmed/25158803
http://dx.doi.org/10.1186/s12934-014-0098-z
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author Zhang, Xiangmei
Xue, Chaoyou
Zhao, Fanglong
Li, Dashuai
Yin, Jing
Zhang, Chuanbo
Caiyin, Qinggele
Lu, Wenyu
author_facet Zhang, Xiangmei
Xue, Chaoyou
Zhao, Fanglong
Li, Dashuai
Yin, Jing
Zhang, Chuanbo
Caiyin, Qinggele
Lu, Wenyu
author_sort Zhang, Xiangmei
collection PubMed
description BACKGROUND: Polyketides, such as spinosad, are mainly synthesized in the stationary phase of the fermentation. The synthesis of these compounds requires many primary metabolites, such as acetyl-CoA, propinyl-CoA, NADPH, and succinyl-CoA. Their synthesis is also significantly influenced by NADH/NAD(+). Rex is the sensor of NADH/NAD(+) redox state, whose structure is under the control of NADH/NAD(+) ratio. The structure of rex controls the expression of many NADH dehydrogenases genes and cytochrome bd genes. Intracellular redox state can be influenced by adding extracellular electron acceptor H(2)O(2). The effect of extracellular oxidoreduction potential on spinosad production has not been studied. Although extracellular oxidoreduction potential is an important environment effect in polyketides production, it has always been overlooked. Thus, it is important to study the effect of extracellular oxidoreduction potential on Saccharopolyspora spinosa growth and spinosad production. RESULTS: During stationary phase, S. spinosa was cultured under oxidative (H(2)O(2)) and reductive (dithiothreitol) conditions. The results show that the yield of spinosad and pseudoaglycone increased 3.11 fold under oxidative condition. As H(2)O(2) can be served as extracellular electron acceptor, the ratios of NADH/NAD(+) were measured. We found that the ratio of NADH/NAD(+) under oxidative condition was much lower than that in the control group. The expression of cytA and cytB in the rex mutant indicated that the expression of these two genes was controlled by rex, and it was not activated under oxidative condition. Enzyme activities of PFK, ICDH, and G6PDH and metabolites results indicated that more metabolic flux flow through spinosad synthesis. CONCLUSION: The regulation function of rex was inhibited by adding extracellular electron acceptor-H(2)O(2) in the stationary phase. Under this condition, many NADH dehydrogenases which were used to balance NADH/NAD(+) by converting useful metabolites to useless metabolites and unefficient terminal oxidases (cytochrome bd) were not expressed. So lots of metabolites were not waste to balance. As a result, un-wasted metabolites related to spinosad and PSA synthesis resulted in a high production of spinosad and PSA under oxidative condition. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12934-014-0098-z) contains supplementary material, which is available to authorized users.
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spelling pubmed-41729462014-09-25 Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa Zhang, Xiangmei Xue, Chaoyou Zhao, Fanglong Li, Dashuai Yin, Jing Zhang, Chuanbo Caiyin, Qinggele Lu, Wenyu Microb Cell Fact Research BACKGROUND: Polyketides, such as spinosad, are mainly synthesized in the stationary phase of the fermentation. The synthesis of these compounds requires many primary metabolites, such as acetyl-CoA, propinyl-CoA, NADPH, and succinyl-CoA. Their synthesis is also significantly influenced by NADH/NAD(+). Rex is the sensor of NADH/NAD(+) redox state, whose structure is under the control of NADH/NAD(+) ratio. The structure of rex controls the expression of many NADH dehydrogenases genes and cytochrome bd genes. Intracellular redox state can be influenced by adding extracellular electron acceptor H(2)O(2). The effect of extracellular oxidoreduction potential on spinosad production has not been studied. Although extracellular oxidoreduction potential is an important environment effect in polyketides production, it has always been overlooked. Thus, it is important to study the effect of extracellular oxidoreduction potential on Saccharopolyspora spinosa growth and spinosad production. RESULTS: During stationary phase, S. spinosa was cultured under oxidative (H(2)O(2)) and reductive (dithiothreitol) conditions. The results show that the yield of spinosad and pseudoaglycone increased 3.11 fold under oxidative condition. As H(2)O(2) can be served as extracellular electron acceptor, the ratios of NADH/NAD(+) were measured. We found that the ratio of NADH/NAD(+) under oxidative condition was much lower than that in the control group. The expression of cytA and cytB in the rex mutant indicated that the expression of these two genes was controlled by rex, and it was not activated under oxidative condition. Enzyme activities of PFK, ICDH, and G6PDH and metabolites results indicated that more metabolic flux flow through spinosad synthesis. CONCLUSION: The regulation function of rex was inhibited by adding extracellular electron acceptor-H(2)O(2) in the stationary phase. Under this condition, many NADH dehydrogenases which were used to balance NADH/NAD(+) by converting useful metabolites to useless metabolites and unefficient terminal oxidases (cytochrome bd) were not expressed. So lots of metabolites were not waste to balance. As a result, un-wasted metabolites related to spinosad and PSA synthesis resulted in a high production of spinosad and PSA under oxidative condition. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12934-014-0098-z) contains supplementary material, which is available to authorized users. BioMed Central 2014-08-27 /pmc/articles/PMC4172946/ /pubmed/25158803 http://dx.doi.org/10.1186/s12934-014-0098-z Text en © Zhang et al.; licensee BioMed Central Ltd. 2014 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Zhang, Xiangmei
Xue, Chaoyou
Zhao, Fanglong
Li, Dashuai
Yin, Jing
Zhang, Chuanbo
Caiyin, Qinggele
Lu, Wenyu
Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa
title Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa
title_full Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa
title_fullStr Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa
title_full_unstemmed Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa
title_short Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa
title_sort suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in saccharopolyspora spinosa
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4172946/
https://www.ncbi.nlm.nih.gov/pubmed/25158803
http://dx.doi.org/10.1186/s12934-014-0098-z
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