Biotechnology for Biofuels
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2018
·Vol. 11
·期 1
·1-16
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IF 5.497
Sun Tao,Li Shubin,Song Xinyu,Pei Guangsheng,Diao Jinjin,Cui Jinyu,Shi Mengliang,Chen Lei,Zhang Weiwen
Background Photosynthetic cyanobacteria have attracted a significant attention as promising chassis to produce renewable fuels and chemicals due to their capability to utilizing solar energy and CO 2 . Notably, the enhancing supply of key precursors like malonyl-CoA would benefit the production of many bio-compounds. Nevertheless, the lacking of genetic tools in cyanobacteria, especially the knockdown strategies for essential pathways, has seriously restricted the attempts to re-direct carbon flux from the central carbohydrate metabolism to the synthesis of bioproducts. Results Aiming at developing new genetic tools, two small RNA regulatory tools are reported for the model cyanobacterium Synechocystis sp. PCC6803, based on paired termini RNAs as well as the exogenous Hfq chaperone and MicC scaffold (Hfq-MicC) previously developed in Escherichia coli . Both regulatory tools functioned well in regulating exogenous reporter gene lacZ and endogenous glgC gene in Synechocystis sp. PCC6803, achieving a downregulation of gene expression up to 90% compared with wildtype. In addition, the Hfq-MicC tool was developed to simultaneously regulate multiple genes related to essential fatty acids biosynthesis, which led to decreased fatty acids content by 11%. Furthermore, aiming to re-direct the carbon flux, the Hfq-MicC tool was utilized to interfere the competing pathway of malonyl-CoA, achieving an increased intracellular malonyl-CoA abundance up to 41% (~ 698.3 pg/mL/OD 730 nm ) compared to the wildtype. Finally, the Hfq-MicC system was further modified into an inducible system based on the theophylline-inducible riboswitch. Conclusions In this study, two small RNA regulatory tools for manipulating essential metabolic pathways and re-directing carbon flux are reported for Synechocystis sp. PCC6803. The work introduces efficient and valuable metabolic regulatory strategies for photosynthetic cyanobacteria.
研究领域:
微生物学
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代谢工程
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合成生物学
✓ 已验证
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2024
·
IF 9.7
Hui-Ying Xu,Ruo-Yu Li,Zi-Qiang Yang,Jia-Fan Qiu,Yu-Bin Su,Carol Sze Ki Lin,Wei-Dong Yang,Hong-Ye Li,Jian-Wei Zheng,Xiang Wang
In this study, the biochemical response of Phaeodactylum tricornutum to varying concentrations of inorganic selenium (Se) was investigated. It was observed that, when combined with fulvic acid, P. tricornutum exhibited enhanced uptake and biotransformation of inorganic Se, as well as increased microalgal lipid biosynthesis. Notably, when subjected to moderate (5 and 10 mg/L) and high (20 and 40 mg/L) concentrations of selenite under fulvic acid treatment, there was a discernible redirection of carbon flux towards lipogenesis and protein biosynthesis from carbohydrates. In addition, the key parameters of microalgae-based biofuels aligned with the necessary criteria outlined in biofuel regulations. Furthermore, the Se removal capabilities of P. tricornutum , assisted by fulvic acid, were coupled with the accumulation of substantial amounts of organic Se, specifically SeCys. These findings present a viable and successful approach to establish a microalgae-based system for Se uptake and biotransformation.
研究领域:
海洋生物学
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环境科学
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生物化学
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生物技术
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
·
IF 11.3
Yingying Sun,Jie Chen,Lizhong Zhu
The prevalence and persistence of phthalate esters (PAEs) in agricultural soils has garnered global attention. Assessing their potential impacts on crop yield and quality necessitates a thorough understanding of their risks. In this study, we elucidated the carbon flow-dependent mechanisms of the decreased grain quality upon exposure to PAEs through a soil-based rice cultivation experiment. Combining metabolomics and transcriptomics methods, our findings revealed that the glycolytic intermediates derived from sucrose breakdown preferentially flowed towards amino acid synthesis, rather than starch and fatty acid synthesis under exposure to dibutyl phthalate (DBP) or di(2-ethylhexyl) phthalate (DEHP). This redirection led to decreased levels of starch (by 14–23 %) and fatty acids (by 10–40 %) in the grains. Notably, the increased amino acids primarily served as antioxidants to mitigate DBP and DEHP stresses, rather than enhancing protein quality. Consequently, a reduction in protein levels by 5.7–38 % was observed. Moreover, our study pinpointed glucose-6-phosphate, a common precursor for amino acids, fatty acids, and starch synthesis, as the crucial branching node in glycolysis that redirected this carbon flow. This study offers a new perspective for evaluating the ecological risks associated with PAEs, paving the way for future research and interventions to mitigate their adverse effects on crops.
研究领域:
环境科学
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植物生理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2025
·
IF 9
Quan Liao,Lianpeng Sun,Xianglin Qin,Ming Chen,Xinzhe Zhu,Chao Yang,Ruo-hong Li
Carbon chain elongation plays a pivotal role in biomass valorization by enabling the efficient conversion of organic substrates into higher-value biochemicals. Ethanol is a key substrate in chain elongation, yet how its oxidation reshapes carbon flux under complex electron transfer networks remains unclear. Based on an open-culture system, this study elucidates how iron species regulate ethanol oxidation. Metagenomic analysis revealed that iron acting as an electron acceptor (e.g., hematite, magnetite) enhanced electron transfer and iron respiration, while serving as an electron donor (e.g., iron powder) activated ethanol metabolism and promoted ATP generation to couple it with chain elongation pathways. These processes improved ethanol oxidation efficiency, redirected carbon flux toward acetate accumulation, and facilitated even-chain elongation of acetate. This study demonstrates an iron-regulated ethanol self-upgrading pathway with significant potential. However, in the presence of fermentation substrates, this phenomenon may reduce substrate conversion efficiency and alter product selectivity. To quantitatively characterize these processes, an integrated evaluation method for ethanol oxidation and self-upgrading was established, providing a robust analytical framework for related phenomena. Overall, this work uncovers the mechanism of bio-iron-mediated carbon flux reorganization and offers both theoretical and practical guidance for the development of advanced ethanol valorization systems and resource-efficient solid waste utilization strategies.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2022
·
IF 11.889
Yue Wang,Bowen Wu,Tian Ma,Yaozu Mi,Hanyi Jiang,Haohao Yan,Peichao Zhao,Shuo Zhang,Linxuan Wu,Lei Chen,Hailian Zang,Chunyan Li
Low-temperature biorefineries inhibit the multiplication of undesired microorganisms, improve product purity and reduce economic costs. Herein, to improve the 2,3-butanediol (2,3-BD) bioconversion efficiency from hemicellulose, a psychrotrophic hemicellulose-degrading strain Raoultella terrigena HC6 with high β-xylosidase activity 1520 U/mL was isolated and genetically modified. Xylan (hemicellulose replacement) was depolymerized into xylooligosaccharides (XOS) and xylose by HC6, which were further converted into 2,3-BD. Transcriptomic analysis revealed that β-xylosidase gene ( xynB ) and xylose isomerase gene ( xylA ), which are beneficial for increasing the carbon flux from xylan to 2,3-BD, were significantly upregulated 56.9-fold and 234-fold, respectively. A recombinant strain was constructed by overexpressing xynB in HC6, which obtained 0.389 g/g yield of 2,3-BD from hemicellulose extracted from corn straw at 15 °C. This study proposed a promised strategy for the bioconversion of agricultural waste into 2,3-BD at low temperatures and provides a basis for future efforts in the achievement of carbon neutrality.
研究领域:
生物技术
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微生物学
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代谢工程
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2022
·
IF 9.224
Ze-Wang Guo,Zi-Fu Ni,Min-Hua Zong,Wen-Yong Lou
Consolidated bioprocessing (CBP) has emerged as a promising strategy for green synthesis of 2,3-butanediol (BDO) from Jerusalem artichoke tubers (JAT). Here, modular metabolic engineering of Bacillus licheniformis MW3 was implemented, in which the overall BDO synthesis process was divided into four modules (inulin hydrolysis, sporulation elimination, carbon flux redistribution, and enantiopure meso-BDO synthesis). First, endo-inulinase was introduced to boost inulin utilization. Second, sporulation was blocked by spoIIE knockout, thus reducing the leakage risk of the genetically engineered strain from the fermentation plant. Third, more carbon flux was shunted into BDO production via exchanging the alsS start codon, blocking acetoin catabolism, and competing pathways. Finally, enantiopure meso-BDO was synthesized by gdh knockout. Encouragingly, the final engineered strain, MWO-8, produced meso-BDO with 99.3% purity at a titer, productivity, and yield of 82.51 g/L, 1.38 g/L/h, and 0.439 g/g, respectively. To our knowledge, this is the highest titer of BDO from JAT by CBP so far. Collectively, this work provides a highly promising alternative approach for sustainable and cost-effective production of BDO.
研究领域:
生物技术
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代谢工程
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生化工程
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微生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）