BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Qiushi Jiang,Yanjing Li,Minmin Wang,Wen Cao,Xueying Yang,Sihu Zhang,Liejin Guo
This study investigated the mediating effect of Triethanolamine on Fe@C- Rhodobacter sphaeroides hybrid photosynthetic system to achieve efficient biohydrogen production. The biocompatible Fe@C generates excited electrons upon exposure to light, releasing ferrum for nitrogenase synthesis, and regulating the pH of the fermentation environment. Triethanolamine was introduced to optimize the electron transfer chain, thereby improving system stability, prolonging electron lifespan, and facilitating ferrum corrosion. This, in turn, stimulated the lactic acid synthetic metabolic pathway of Rhodobacter sphaeroides , resulting in increased reducing power in the biohybrid system. The ternary coupling system was analyzed through the regulation of concentration, initial pH, and light intensity. The system achieved the highest total H 2 production of 5410.9 mL/L, 1.29 times higher than the control (2360.5 mL/L). This research provides a valuable strategy for constructing ferrum-carbon-based composite-cellular biohybrid systems for photo-fermentation H 2 production.
研究领域:
微生物学
·
可再生能源
·
光合作用
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Yaqin Wang,Lingjia Fan,Jintao Huang,Jingjing Liang,Xingnan Wang,Yichen Ren,Hongcai Li,Tianli Yue,Zhenpeng Gao
To prepare pumpkin juice (PJ) rich in coenzyme Q10, this study analyzed the chemical composition, antioxidant activity, and gut microbiota of pumpkin juice fermented by Rhodobacter sphaeroides (RPJ). The number of viable bacteria in the juice reached 2.8 × 10 8 CFU/mL; the fermentation process mainly consumed glucose and sucrose; the total sugar content was reduced, β -carotene was reduced, and a new antioxidant substance, coenzyme Q10, appeared at a content of 12.345 mg/L; levels of volatile alcohols, esters, and ketones significantly increased; and antioxidation ability improved, particularly the ferric ion reducing antioxidant power activity. The gut microbiota of mice shifted by increasing Lactobacillus and Bifidobacterium and protected the gut barrier by reducing Proteobacteria after 48 h of fermentation. Pumpkin juice fermented by Rhodobacter sphaeroides not only produces bioactive substances with antioxidant capacity but can also regulate the gut microbiota of mice.
研究领域:
食品科学
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微生物学
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营养学
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生物化学
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产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2025
·
IF 9
Xinru Bao,Jie Zhong,Zikang Huang,Guangyi Xiao,Qiaomin Yang,Wenkang Yu,Bingmei Wang,Wenjin He,Naipeng Kan,Jianzhong Huang,Feng Qi
Coenzyme Q10 (CoQ 10 ), a lipid-soluble isoprenylated benzoquinone essential for electron transfer, is synthesized in the inner mitochondrial membrane of eukaryotes and plasma membrane of prokaryotes like Rhodobacter sphaeroides . Despite its natural production capacity, industrial-scale CoQ 10 synthesis remains limited by ineffective metabolic regulation and scarce genetic tools in R. sphaeroides . This study investigated the relationship between CoQ 10 and intracellular lipid accumulation to enhance production. The engineered strains with higher cardiolipin (CL) levels showed enlarged membrane surfaces, synergistically increasing CoQ 10 production. However, increased triacylglycerol (TAG) accumulation reduced CoQ 10 yields. Disrupting phospholipase D (PLD) and lysophospholipase (PLDB) genes, which reduce phospholipid hydrolysis, further improved CoQ 10 biosynthesis. The optimized strain RS-SQCL04, incorporating all the effective strategies, achieved 824 mg/L CoQ 10 via fed-batch fermentation, a 57.9 % increase over the control. This study provides a promising strategy for industrial CoQ 10 production through phospholipid engineering in R. sphaeroides .
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产品关联
DOI
PubMed
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2013
·Vol. 30
·期 1
·245-252
·
IF 1.262
Wang Hualei,Li Guinan,Li Mingyang,Wei Dongzhi,Wang Xuedong
In this study, a novel nitrilase gene from Rhodobacter sphaeroides was cloned and overexpressed in Escherichia coli . The open reading frame of the nitrilase gene includes 969 base pairs, which encodes a putative polypeptide of 322 amino acid residues. The molecular weight of the purified native nitrilase was about 560 kDa determined by size exclusion chromatography. This nitrilase showed one single band on SDS-PAGE with a molecular weight of 40 kDa. This suggested that the native nitrilase consisted of 14 subunits with identical size. The optimal pH and temperature of the purified enzyme were 7.0 and 40 °C, respectively. The kinetic parameters V
max and K
m toward 3-cyanopyridine were 77.5 μmol min −1 mg −1 and 73.1 mmol/l, respectively. The enzyme can easily convert aliphatic nitrile and aromatic nitriles to their corresponding acids. Furthermore, this enzyme demonstrated regioselectivity in hydrolysis of aliphatic dinitriles. This specific characteristic makes this nitrilase have a great potential for commercial production of various cyanocarboxylic acids by hydrolyzing readily available dinitriles.
研究领域:
微生物学
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生物化学
·
酶学
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生物技术
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DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2012
·Vol. 97
·期 8
·3355-3362
·
IF 3.425
Guo Fei,Xu Haoming,Xu Hongna,Yu Hongwei
Despite directed evolution being a practical and efficient method of improving the properties of enzymes, a trade-off between the targeted property and other essential properties often exists which hinders the efficiency of directed evolution. In our previous work, mutant CVH of an esterase from Rhodobacter sphaeroides with high enantioselectivity was obtained by directed evolution, unfortunately its activity cannot catch another mutant YH. To compensate the trade-off of mutant CVH, site-directed saturation mutagenesis was conducted on four residues, three (Asn62, Met121, and Leu145) were hot spots determined from directed evolution, and one (Tyr27) was introduced to make up the large distance between a mutation (Asn62) and the substrate. A new mutant (HMVY) with high enantioselectivity and comparable activity to YH was obtained. According to the kinetic analysis and molecular dynamics simulations, it was understood that the high enantioselectivity and poor activity of mutant CVH was caused by different decrement of efficiency constants to two isomers, ( R )-, ( S )-methyl mandelate, and the high enantioselectivity and activity of mutant HWVY was caused by improved activity towards the preferred substrate (( S )-methyl mandelate), which provided the interpretation of the trade-off compensation. This work could provide a way to compensate the trade-off of enantioselectivity and activity in the process of enzyme evolution.
研究领域:
生物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）