BIOTECHNOLOGY AND BIOENGINEERING
·
2014
·Vol. 111
·期 12
·2580-2586
·
IF 4.164
Jia-Le Yu,Xiao-Xia Xia,Jian-Jiang Zhong,Zhi-Gang Qian
The C6 dicarboxylic acid, adipic acid, is an important platform chemical in industry. Biobased production of adipic acid is a promising alternative to the current petrochemical route. Here, we report biosynthesis of adipic acid using an artificial pathway inspired by the reversal of beta-oxidation of dicarboxylic acids. The biosynthetic pathway comprises condensation of acetyl-CoA and succinyl-CoA to form the C6 backbone and subsequent reduction, dehydration, hydrogenation, and release of adipic acid from its thioester. The pathway was first tested in vitro with reconstituted pathway enzymes and then functionally introduced into Escherichia coli for the biosynthesis and excretion of adipic acid into the culture medium. The production titer was increased by approximately 20-fold through the combination of recruiting enzymes that were more suitable to catalyze the synthetic reactions and increasing availability of the condensation substrates. This work demonstrates direct biosynthesis of adipic acid via non-natural synthetic pathway, which may enable its renewable production. Biotechnol. Bioeng. 2014;111: 2580–2586. © 2014 Wiley Periodicals, Inc.
研究领域:
生物技术
·
代谢工程
·
合成生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 13
·4105-4114
·
IF 5.368
Xi Chen,Nan Zheng,Qiao Wang,Lingzhi Liu,Yongfeng Men
The influence of different synthetic pathways on the phase transition and side-chain crystallization behavior of cellulose ethers was systematically investigated by a combination of differential scanning calorimetry (DSC), small and wide-angle X-ray scattering (SAXS, WAXS) and Fourier transform infrared spectroscopy (FTIR) techniques. DSC investigation indicated that the melting temperature and crystallization temperature, respectively, of cellulose derivatives that were synthesized by homogeneous reactions in cellulose solutions differed from those of cellulose aggregates in a swollen state synthesized by heterogeneous reactions; this implies that the synthetic pathway had a strong effect on the side-chain crystallization behavior in comb-like polymers. WAXS results showed that the cellulose ethers prepared by homogeneous reaction packed into hexagonal crystals, while those prepared by heterogeneous reaction exhibited multiple crystals. These phenomena may be understood as a result of the effect of the regularity of the main chain and the difference in hydrogen bonding interactions in the two kinds of cellulose ethers. For the latter, the presence of free –OH groups at the C-6 position in the samples obtained via the heterogeneous reaction is considered to contribute critically to intermolecular hydrogen bonds that promote crystallization of the system.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
DOI
高影响因子
CHEMBIOCHEM
·
2025
·
IF 2.8
Shiqi Luo,Wei Song,Guipeng Hu,Jian Wen,Xiaomin Li,Cong Gao,Jia Liu,Wanqing Wei,Liming Liu
Graphical Here, we have constructed a dual-enzyme ( Ec TnaA, Ma FMO) cascade pathway for the biosynthesis of indigo from L-tryptophan and enhanced the enzymatic activity of Ma FMO through mechanism-guided rational design. Subsequently, by optimizing promoters and increasing copy numbers to regulate the expression levels of Ec TnaA and Ma FMO D197E , under optimal conditions, E. coli IND-13 achieved the highest yield to date using glucose as the substrate. Indigo is widely used in dyes, medicines and semiconductors materials due to its excellent dyeing efficiency, antibacterial, antiviral, anticancer, anti-corrosion, and thermostability properties. Here, a biosynthetic pathway for indigo was designed, integrating two enzymes ( Ec TnaA, Ma FMO) into a higher L-tryptophan-producing the strain Escherichia coli TRP. However, the lower catalytic activity of Ma FMO was a bottleneck for increasing indigo titers. To overcome this limitation, the enzyme activity of Ma FMO was enhanced through mechanism-guided rational design. The optimal mutant obtained in this study, Ma FMO D197E , whose k cat / K m was 1.34 times that of the wild type, and its specific activity was 2.36 times that of the wild type. In addition, the expression levels of Ec TnaA and Ma FMO D197E were regulated by optimizing the promoters and increasing the copy number to generate the strain E. coli IND-13. Finally, in the optimal fermentation conditions (220 rpm, 0.05 % Tween-80), the strain E. coli IND-13 achieved the indigo titer of 568.52 mg/L in a 5-L bioreactor, with the yield and productivity of 2.62 mg/g and 12.96 mg/L/h (the highest to date), respectively. The results presented here can lay a foundation for further construction of cell factories for indigo and its derivatives with industrial application potential.
研究领域:
合成生物学
·
微生物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Synthetic Biology
·
2021
·
IF 5.11
Min Liu,Yang-Chen Lin,Jiao-Jiao Guo,Meng-Meng Du,Xinyi Tao,Bei Gao,Ming Zhao,Yushu Ma,Feng-Qing Wang,Dong-Zhi Wei
Patchoulol is a tricyclic sesquiterpene widely used in perfumes and cosmetics. Herein, comprehensive engineering strategies were employed to construct an efficient yeast strain for patchoulol production. First, a platform strain was constructed via pathway modification. Second, three off-pathway genes were deleted, which led to significant physiological changes in yeast. Further, strengthening of the ergosterol pathway, enhancement of the energy supply, and a decrease in intracellular reactive oxygen species were implemented to improve the physiological status of yeast, demonstrating a new promotive relationship between ergosterol biosynthesis and synthesis of patchoulol. Moreover, patchoulol synthase was improved through protein modification and Mg2+ addition, reaching a final titer of 141.5 mg/L in a shake flask. Finally, a two-stage fermentation with dodecane addition was employed to achieve the highest production (1632.0 mg/L, 87.0 mg/g dry cell weight, 233.1 mg/L/d) ever reported for patchoulol in a 5 L bioreactor. This work lays a foundation for green and efficient patchoulol production.
研究领域:
生物技术
·
代谢工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE
·
2016
·Vol. 141
·期 4
·327-338
·
IF 1
Yan Li,Hongyan Qi,Yazhong Jin,Xiaobin Tian,Linlin Sui,Yan Qiu
The catabolism of fatty acid (FA) is regarded as a key pathway of aroma volatile compounds in oriental sweet melon (Cucumis melo var. makuwa). In our research, two cultivars of oriental sweet melon, Caihong7 and Tianbao, were employed to illuminate which step of the biosynthetic pathway of aroma compounds could be regulated by ethylene (ETH). The role of ETH in determining the profiles of straight-chain aroma volatile compounds, levels of FA as aroma precursors, activities of aroma-related enzymes derived from FA pathway, and expression patterns of key enzymes were investigated. Overall, exogenous application of ETH increased the production rates of endogenous ETH and levels of FA. Compared with control, the level of straight-chain esters, especially the acetate, hexanoate, and hexyl esters, was significantly increased by ETH, whereas the content of alcohol and aldehyde reduced. In addition, the metabolism of free FA included linoleic acid (LA), linolenic acid (LeA), and oleic acid (OA) appeared to be ETH-dependent. The activities of lipoxygenase (LOX), alcohol dehydrogenase (ADH), and alcohol acetyltransferase (AAT) as well as the expression patterns of Cm-ADH1, Cm-ADH2, Cm-AAT1, and Cm-AAT4 were positively regulated by ETH. In contrast, hydroperoxide lyase (HPL) and Cm-AAT2 and Cm-AAT3 seemed to be independent of ETH modulation. These results suggested that the dissimilation of FA included LA, LeA, and OA into the acetate, hexanoate, and hexyl esters mainly through ETH regulating the LOX pathway by enhancing the expression of particular members of aroma-related key enzyme gene families as well as the activities of dehydrogenation and esterification.
研究领域:
植物学
·
园艺学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
BIOTECHNOLOGY LETTERS
·
2015
·Vol. 38
·期 1
·81-88
·
IF 1.591
Jiang Jingjie,Bi Huiping,Zhuang Yibin,Liu Shaowei,Liu Tao,Ma Yanhe
Objectives To achieve high production of rosmarinic acid and derivatives in Escherichia coli which are important phenolic acids found in plants, and display diverse biological activities. Results The synthesis of rosmarinic acid was achieved by feeding caffeic acid and constructing an artificial pathway for 3,4-dihydroxyphenyllactic acid. Genes encoding the following enzymes: rosmarinic acid synthase from Coleus blumei , 4-coumarate: CoA ligase from Arabidopsis thaliana , 4-hydroxyphenyllactate 3-hydroxylase from E. coli and d -lactate dehydrogenase from Lactobacillus pentosus , were overexpressed in an l -tyrosine over-producing E. coli strain. The yield of rosmarinic acid reached ~130 mg l −1 in the recombinant strain. In addition, a new intermediate, caffeoyl-phenyllactate (~55 mg l −1 ), was also produced by the engineered E. coli strain. Conclusion This work not only leads to high yield production of rosmarinic acid and analogues, but also sheds new light on the construction of the pathway of rosmarinic acid in E. coli .
研究领域:
生物化学
·
合成生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Fermentation-Basel
·
2024
·Vol. 10
·期 4
·211
·
IF 3.3
Qiu Tao,Guocheng Du,Jian Chen,Juan Zhang,Zheng Peng
Patchoulol is a natural sesquiterpene alcohol with extensive applications in cosmetics and pharmaceuticals. In this study, we first constructed the synthesis pathway of patchoulol inSaccharomyces cerevisiaeby expressing the patchoulol synthasePTSgene using the strong promoterGAL1. Afterward, the metabolic flux of the precursor was enhanced by strengthening the mevalonate pathway and balancing the precursor competition pathway, resulting in a 32.74-fold increase in patchoulol production. Subsequently, the supply of acetyl-CoA in yeast was increased by modifying transcriptional regulators and modulating the acetyl-CoA pathway, and the titer of patchoulol reached 155.94 mg/L. Finally, optimization of the fermentation conditions resulted in a titer of 195.96 mg/L in the shake flasks. Further, batch-fed fermentation in a 5 L bioreactor yielded 1.95 g/L. This work accelerated the development of a microbial cell factory for the production of patchoulol.
研究领域:
生物化学
·
代谢工程
·
合成生物学
✓ 已验证
DOI
高影响因子
Microbial Cell Factories
·
2024
·Vol. 23
·期 1
·1-13
·
IF 4.3
Zhao Siyu,Shi Tangen,Li Liangwen,Chen Zhichao,Li Changgeng,Yu Zichen,Sun Pengjie,Xu Qingyang
Background Hypoxanthine, prevalent in animals and plants, is used in the production of food additives, nucleoside antiviral drugs, and disease diagnosis. Current biological fermentation methods synthesize quantities insufficient to meet industrial demands. Therefore, this study aimed to develop a strain capable of industrial-scale production of hypoxanthine. Results De novo synthesis of hypoxanthine was achieved by blocking the hypoxanthine decomposition pathway, thus alleviating transcriptional repression and multiple feedback inhibition, and introducing a purine operon from Bacillus subtilis to construct a chassis strain. The effects of knocking out the IMP(Inosine 5’-monophosphate) branch on the growth status and titer of the strain were then investigated, and the effectiveness of adenosine deaminase and adenine deaminase was verified. Overexpressing these enzymes created a dual pathway for hypoxanthine synthesis, enhancing the metabolic flow of hypoxanthine synthesis and preventing auxotrophic strain formation. Introducing IMP-specific 5’ -nucleotidase addressed the issue of adenylate accumulation. In addition, the metabolic flow of the guanine branch was dynamically regulated by the guaB gene. The supply of glutamine and aspartic acid precursors was enhanced by introducing an exogenous glnA mutant gene, overexpressing aspC , and replacing the weaker promoter to regulate the aspartic acid branching pathway. Ultimately, fermentation in a 5 L bioreactor for 48 h produced 30.6 g/L hypoxanthine, with a maximum real-time productivity of 1.4 g/L/h, the highest value of hypoxanthine production by microbial fermentation reported so far. Conclusions The intracellular purine biosynthesis pathway is extensive and regulated at multiple levels in cells. The IMP branch in the hypoxanthine synthesis pathway has a higher metabolic flux. The current challenge lies in systematically allocating the metabolic flux within the branch pathway to achieve substantial product accumulation. In this study, E. coli was used as the chassis strain to construct a dual pathway for IMP and AMP(Adenosine 5’-monophosphate) synergistic hypoxanthine synthesis and dynamically regulate the guanine branch pathway. Overall, our experimental efforts culminated in a high-yield, plasmid- and defect-free engineered hypoxanthine strain.
研究领域:
微生物学
·
生物工程
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
Ying Zhou,Qiyuan Peng,Lanting Zeng,Jinchi Tang,Jianlong Li,Fang Dong,Ziyin Yang
After tea leaves, tea ( Camellia sinensis ) flowers are becoming a second tea plant resource because they contain not only functional metabolites similar to those found in tea leaves, but also predominant amounts of functional metabolites that only occur in tea leaves in small amounts. 1-Phenylethanol (1PE) is a predominant aroma compound found in tea flowers. A 1PE synthase in tea flowers was isolated, functionally characterized, and shown to have the highest catalytic efficiency for the conversion of acetophenone (AP). To determine why 1PE accumulates more in tea flowers than other plants, we compared their 1PE contents and used a stable isotope labeling method to elucidate the 1PE biosynthetic route. Supplementation with [ 2 H 8 ] l -phenylalanine and [ 2 H 5 ]AP suggested that most plants containing the enzyme/gene catalyzed the conversion of AP to 1PE. Furthermore, the availability of AP derived from l -phenylalanine was responsible for the difference in 1PE accumulation between tea flowers and other plants.
研究领域:
植物学
·
生物化学
·
植物代谢
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Xiaochong Zhu,Jieyuan Wu,Shizhong Li,La Xiang,Jian-Ming Jin,Chaoning Liang,Shuang-Yan Tang
Eugenol, the main component of essential oil from the Syzygium aromaticum clove tree, has great potential as an alternative bioresource feedstock for biosynthesis purposes. Although eugenol degradation to ferulic acid was investigated, an efficient method for directly converting eugenol to targeted natural products has not been established. Herein we identified the inherent inhibitions by simply combining the previously reported ferulic acid biosynthetic pathway and vanillin biosynthetic pathway. To overcome this, we developed a novel biosynthetic pathway for converting eugenol into vanillin, by introducing cinnamoyl-CoA reductase (CCR), which catalyzes conversion of coniferyl aldehyde to feruloyl-CoA. This approach bypasses the need for two catalysts, namely coniferyl aldehyde dehydrogenase and feruloyl-CoA synthetase, thereby eliminating inhibition while simplifying the pathway. To further improve efficiency, we enhanced CCR catalytic efficiency via directed evolution and leveraged an artificialvanillin biosensor for high-throughput screening. Switching the cofactor preference of CCR from NADP+ to NAD+ significantly improved pathway efficiency. This newly designed pathway provides an alternative strategy for efficiently biosynthesizing feruloyl-CoA-derived natural products using eugenol.
研究领域:
生物化学
·
合成生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Carbohydrate Polymer Technologies and Applications
·
2025
·
IF 6.5
Siyu Liu,Jiaqi Luo,Ying Shi,Qihe Chen
Various bacterial species synthesize bacterial cellulose (BC), each exhibiting unique metabolic pathways and environmental adaptations. Herein, the microbial profile of Monascus vinegar biofilm was analyzed for the first time using metagenome sequencing, and a BC-producing bacteria, Komagataeibacter europaeus FMES, was isolated from Monascus vinegar biofilm and identified as a novel strain. The complete genome of strain FMES was analyzed using whole genome sequencing, revealing carbon metabolism and BC biosynthesis pathways in detail. The biosynthesis of BC is regulated by the bacterial cellulose synthase ( bcs ) operon, and three bcs operons were identified in the genome. Additionally, the BC production of strain FMES was evaluated under static conditions using different carbon sources. The highest BC yield of 5.89 ± 0.38 g/L was achieved using 5% glycerol as the only carbon source. The addition of 3% ethanol enhanced the biosynthesis of BC by K. europaeus FMES. This work brings valuable insights into the isolation of BC-producing strains from fermented foods and the metabolic pathways of BC synthesis, which provides useful information for further biological research on Komagataeibacter spp., and the potential use of BC in medical wound care and sustainable packaging.
研究领域:
微生物学
·
分子生物学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
Fermentation-Basel
·
2025
·Vol. 11
·期 5
·246
·
IF 3.3
Xiaoyan Sun,Yunpeng Wang,Yijie Wang,Jingwen Zhou,Jianghua Li,Jian Chen,Guocheng Du,Xinrui Zhao
Currently, various types of myoglobins and hemoglobins are widely used in the fields of food additives and biocatalytic applications. However, the limited availability of heme constrains the biosynthesis of these high-activity hemoproteins in microbial chassis cells. In this work, a new heme synthetic pathway was reconstructed in the mitochondria by eliminating the spatial barrier during heme synthesis inSaccharomyces cerevisiae, resulting in a significant enhancement in intracellular heme supply. To further enhance the supply of the essential precursor for heme synthesis (5-aminolevulinate, ALA), the special ALA exporter in the mitochondrial membrane (Ort1p) was identified and knocked out. Moreover, the mitochondrial heme exporter (Ygr127wp) was overexpressed to promote the transport of heme to the cytoplasm to participate in the synthesis of various myoglobins and hemoglobins. Based on these strategies in the engineered strain, the binding ratios of heme in porcine myoglobin (52.4 ± 4.9%) and soybean hemoglobin (75.5 ± 2.8%) were, respectively, increased by 2.4-fold and 3.6-fold, and the titers of porcine myoglobin (130.5 ± 2.8 mg·L−1) and soybean hemoglobin (152.8 ± 2.6 mg·L−1), respectively, increased by 31.1% and 42.1%. Furthermore, the engineered strain presents great potential in the efficient synthesis of other heme-binding proteins and enzymes inS. cerevisiae.
研究领域:
生物工程
·
合成生物学
✓ 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）