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High production of butyric acid by

Chao Ma,Jianfa Ou,Matthew Miller,Sarah McFann,Xiaoguang (Margaret) Liu

《化学科学与工程前沿（英文）》 2015年 第9卷 第3期   页码 369-375 doi: 10.1007/s11705-015-1525-3

摘要： The objective of this study was to improve the production of butyric acid by process optimization using the metabolically engineered mutant of (PAK-Em). First, the free-cell fermentation at pH 6.0 produced butyric acid with concentration of 38.44 g/L and yield of 0.42 g/g. Second, the immobilized-cell fermentations using fibrous-bed bioreactor (FBB) were run at pHs of 5.0, 5.5, 6.0, 6.5 and 7.0 to optimize fermentation process and improve the butyric acid production. It was found that the highest titer of butyric acid, 63.02 g/L, was achieved at pH 6.5. Finally, the metabolic flux balance analysis was performed to investigate the carbon rebalance in . The results show both gene manipulation and fermentation pH change redistribute carbon between biomass, acetic acid and butyric acid. This study demonstrated that high butyric acid production could be obtained by integrating metabolic engineering and fermentation process optimization.

关键词： Clostridium tyrobutyricum     butyric acid production     fermentation     mutant     pH     flux balance analysis    

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Continuous biohydrogen production from diluted molasses in an anaerobic contact reactor

Sheng CHANG, Jianzheng LI, Feng LIU

《环境科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 140-148 doi: 10.1007/s11783-010-0258-2

摘要： An anaerobic contact reactor (ACR) system comprising a continuous flow stirred tank reactor (CSTR) with settler to decouple the hydraulic retention time (HRT) from solids retention time (SRT) was developed for fermentative hydrogen production from diluted molasses by mixed microbial cultures. The ACR was operated at various volumetric loading rates (VLRs) of 20–44 kgCOD·m ·d with constant HRT of 6 h under mesophilic conditions of 35°C. The SRT was maintained at about 46–50 h in the system. At the initial VLR of 20 kgCOD·m ·d , the hydrogen production rate dropped from 22.6 to 1.58 L·d as the hydrogen was consumed by the hydrogentrophic methanogen. After increasing the VLR to 28 kgCOD·m ·d and discharging the sludge for 6 consecutive times, the hydrogentrophic methanogens were eliminated, and the hydrogen content reached 36.4%. As the VLR was increased to 44 kgCOD·m ·d , the hydrogen production rate and hydrogen yield increased to 42.1 L·d and 1.40 mol H ·molglucose-consumed , respectively. The results showed that a stable ethanol-type fermentation that favored hydrogen production in the reactor was thus established with the sludge loading rate (SLR) of 2.0–2.5 kgCOD·kgMLVSS ·d . It was found that the ethanol increased more than other liquid fermentation products, and the ethanol/acetic acid (mol/mol) ratio increased from 1.27 to 2.45 when the VLR increased from 28 to 44 kgCOD·m ·d , whereas the hydrogen composition decreased from 40.4% to 36.4%. The results suggested that the anaerobic contact reactor was a promising bioprocess for fermentative hydrogen production.

关键词： fermentative hydrogen production     anaerobic contact reactor (ACR)     sludge loading rate (SLR)     butyric acid-type fermentation     ethanol-type fermentation    

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Genomic and metabolomic analysis of with enhanced poly--glutamic acid production through atmospheric

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1751-1760 doi: 10.1007/s11705-022-2211-x

摘要： Poly-γ-glutamic acid is an extracellular polymeric substance with various applications owing to its valuable properties of biodegradability, flocculating activity, water solubility, and nontoxicity. However, the ability of natural strains to produce poly-γ-glutamic acid is low. Atmospheric and room temperature plasma was applied in this study to conduct mutation breeding of Bacillus licheniformis CGMCC 2876, and a mutant strain M32 with an 11% increase in poly-γ-glutamic acid was obtained. Genome resequencing analysis identified 7 nonsynonymous mutations of ppsC encoding lipopeptide synthetase associated with poly-γ-glutamic acid metabolic pathways. From molecular docking, more binding sites and higher binding energy were speculated between the mutated plipastatin synthase subunit C and glutamate, which might contribute to the higher poly-γ-glutamic acid production. Moreover, the metabolic mechanism analysis revealed that the upregulated amino acids of M32 provided substrates for glutamate and promoted the conversion between L- and D-glutamate acids. In addition, the glycolytic pathway is enhanced, leading to a better capacity for using glucose. The maximum poly-γ-glutamic acid yield of 14.08 g·L–1 was finally reached with 30 g·L–1 glutamate.

关键词： ARTP mutagenesis     Bacillus licheniformis     poly-γ-glutamic acid     metabolomics    

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Biodiesel production by the transesterification of cottonseed oil by solid acid catalysts

CHEN He, PENG Baoxiang, WANG Dezheng, WANG Jinfu

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 11-15 doi: 10.1007/s11705-007-0003-y

摘要： Methyl esters (biodiesel) were produced by the transesterification of cottonseed oil with methanol in the presence of solid acids as heterogeneous catalysts. The solid acids were prepared by mounting HSO on TiO · nHO and Zr(OH), respectively, followed by calcining at 823K. TiO-SO and ZrOSO showed high activity for the transesterification. The yield of methyl esters was over 90% under the conditions of 230°C, methanol/oil mole ratio of 12:1, reaction time 8 h and catalyst amount (catalyst/oil) of 2% (w). The solid acid catalysts showed more better adaptability than solid base catalysts when the oil has high acidity. IR spectral analysis of absorbed pyridine on the samples showed that there were Lewis and BrØnsted acid sites on the catalysts.

关键词： BrØnsted     reaction     presence     cottonseed     biodiesel    

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Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1198-1210 doi: 10.1007/s11705-021-2133-z

摘要： Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and fabricated. The synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscope-energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area, thermogravimetric analysis and n-butylamine acidity. The shape of catalysts particles plays an important role in its activity. The sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel production. The catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid, oleic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, catalyst amount, reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum conversion. It was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica catalysts. Additionally, the catalyst was regenerated and reused up to three cycles without any significant loss in activity. The present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

关键词： solid acid catalyst     mesoporous silica     sulfonic acid     biodiesel     esterification     oleic acid    

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Factors affecting production of nonaqueous peracetic acid in tubular packed reactors

ZHANG Tengyun, FAN Hongbo, ZHONG Li, CHUANG Karl

《化学科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 196-203 doi: 10.1007/s11705-008-0037-9

摘要： The synthesis of nonaqueous peracetic acid in acetone by acetaldehyde oxidation was carried out in a tubular packed reactor. The influencing factors of the reacting system including packing material, oxygen carrier, and reactor configuration were investigated. The results show that porous materials are inappropriate for peracetic acid synthesis and only non porous material with appropriate surface area can provide good peracetic acid selectivity and yield. Among the six kinds of packing material investigated, SA-5118 is the best one. As oxidizing gas, pure oxygen is superior to air. The optimum length-to-inner diameter ratio of the reactor is about 40. Under the proper reaction conditions, the highest peracetic acid yield of 84.15% and the highest selectivity of 93.34% can be achieved which indicates that the novel reacting system is effective and economical for nonaqueous peracetic acid production.
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Use of dry yeast cells as a cheap nitrogen source for lactic acid production by thermophilic

Kim Yng Ooi, Jin Chuan Wu

《化学科学与工程前沿（英文）》 2015年 第9卷 第3期   页码 381-385 doi: 10.1007/s11705-015-1534-2

摘要： Dry yeast cells (DYC) were used as a cheap nitrogen source to replace expensive yeast extract (YE) for L-lactic acid production by thermophilic . Cassava starch (200 g·L ) was converted to L-lactic acid by simultaneous saccharification and fermentation using WCP10-4 at 50 °C in the presence of 20 g·L of DYC, giving 148.1 g·L of L-lactic acid at 27 h with a productivity of 5.5 g·L ·h and a yield of 92%. In contrast, 154.4 g·L of lactic acid was produced at 24 h with a productivity of 6.4 g·L ·h and a yield of 96% when equal amount of YE was used under the same conditions. Use of pre-autolyzed DYC at 50 °C for overnight slightly improved the lactic acid titer (154.5 g·L ) and productivity (7.7 g·L ·h ) but gave the same yield (96%).

关键词： L-lactic acid     thermophilic strain     Bacillus coagulans     dry yeast cells     autolysis     fermentation    

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Enhanced production of

Shen Huang,Xudong Feng,Chun Li

《化学科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 501-510 doi: 10.1007/s11705-015-1544-0

摘要： -Glucuronidase from Li-3 (PGUS) can efficiently hydrolyze glycyrrhizin into the more valuable glycyrrhetic acid monoglucuronide. However, a low productivity of PGUS and the lack of an effective separation strategy have significantly limited its industrial applications. Therefore, the production of PGUS has been improved by optimizing both the fermentation and purification strategies. A two-stage fermentation strategy was developed where PGUS was first grown with glucose and then PGUS was produced in the presence of glycyrrhizin as an inducer. By using this strategy, the biomass was increased 1.5 times and the PGUS activity increased 5.4 times compared to that when glycyrrhizin was used as the sole carbon source. The amount of PGUS produced was increased another 16.6% when the fermentation was expanded to a 15-L fermenter. An effective protocol was also established to purify the PGUS using a sequential combination of hydrophobic, strong anion-exchange and gel filtration chromatography. This protocol had a recovery yield of 6% and gave PGUS that was 39 times purer than the crude PGUS. The purified PGUS had a specific activity of 350 U·mg .

关键词： β-glucuronidase     glycyrrhetic acid monoglucuronide     cell disruption     purification     chromatography    

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Synthesis of magnetic carbonaceous acid derived from waste garlic peel for biodiesel production via esterification

Hewei YU, Jinke WU, Wei WEI, Xingyu ZHANG, Changzai REN, Yaoqi DONG, Shen CHENG

《能源前沿（英文）》 2023年 第17卷 第1期   页码 176-187 doi: 10.1007/s11708-022-0836-6

摘要： Waste biomass-supported magnetic solid acids have particular advantages in catalyst separation. First, a novel magnetic carbonaceous catalyst was synthesized from waste garlic peel (GP) via in situ impregnation before conducting carbonization at 450–600°C and sulfonation at 105°C. The physical and chemical properties of the synthesized catalysts were characterized. It was found that the magnetism of the catalyst increased with the carbonization temperature. The optimized catalyst, carbonized at 600°C (C600-S), possessed an excellent magnetization value of 12.5 emu/g, with a specific surface area of 175.1 m2/g, a pore volume of 0.16 cm3/g, and an acidic property of 0.74 mmol/g -SO3H density. By optimizing the esterification conditions to produce biodiesel, an oleic acid conversion of 94.5% was achieved at w(catalyst dosage) = 10% (w is mass fraction), a molar ratio of n(methanol): n(oleic acid) = 10: 1 (n is the amount of substance), and a reaction for 4 h at 90°C. Further, for catalyst regeneration, it was found that sulfuric acid treatment was more effective for improving the esterification activity than solvent washing, with which a conversion of more than 76% was achieved after the third run.

关键词： garlic peel (GP)     magnetic carbonaceous acid     esterification     biodiesel    

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A pulsed switching peroxi-coagulation process to control hydroxyl radical production and to enhance 2,4-Dichlorophenoxyacetic acid degradation

Yaobin Lu, Songli He, Dantong Wang, Siyuan Luo, Aiping Liu, Haiping Luo, Guangli Liu, Renduo Zhang

《环境科学与工程前沿（英文）》 2018年 第12卷 第5期 doi: 10.1007/s11783-018-1070-7

摘要：

• A new pulsed switching peroxi-coagulation (PSPC) system was developed.

• The ECT for 2,4-D removal in the PSPC was lower than that in the EF.

• The iron consumption for 2,4-D removal in the PSPC was lower than that in the PC.

关键词： Pulsed switching peroxi-coagulation system     Energy consumption     Hydroxyl radical production     2     4- Dichlorophenoxyacetic acid    

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Statistical modeling and optimization for enhanced hyaluronic acid production by batch culture of Sreptococcus

Long LIU, Haiquan YANG, Guocheng DU, Miao WANG, Jian CHEN,

《化学科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 351-356 doi: 10.1007/s11705-009-0248-8

摘要： This work is aimed to achieve the optimal hyaluronic acid (HA) production by batch culture of via the supplement of nucleotide bases using response surface methodology (RSM). First, the influence of nucleotide bases (adenine, guanine, cytosine, thymine, and uracil) on microbial HA production was investigated using fractional factorial design (FFD). By a 2 FFD, uracil was found to be the most significant factor for cell growth and HA production, while the other nucleotide bases were shown to have no significant effects on cell growth and HA production. Also, the impact of uracil on cell growth and HA production was further investigated by RSM, where two variables were considered: uracil concentration and supplement time. The optimal uracil concentration and supplement time were found to be 0.051g/L and 7h, respectively, and the predicted maximal HA production reached 6.42g/L. The maximal HA production increased from 5.0g/L of the control without uracil supplement to 6.31g/L at the optimal conditions in validation experiments.

关键词： control     microbial HA     thymine     influence     culture    

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Biodiesel production from waste frying oil in sub- and supercritical methanol on a zeolite Y solid acid

Jorge MEDINA-VALTIERRA, Jorge RAMIREZ-ORTIZ

《化学科学与工程前沿（英文）》 2013年 第7卷 第4期   页码 401-407 doi: 10.1007/s11705-013-1354-1

摘要： Waste frying oil (WFO) is a very important feedstock for obtaining biodiesel at low cost and using WFO in transesterification reactions to produce biodiesel helps eliminate local environmental problems. In this study biodiesel was produced from WFO in sub- and super-critical methanol on a zeolite Y solid acid catalyst. The procedure was optimized using a design of experiments by varying the methanol to WFO molar ratio, the reaction temperature, and the amount of catalyst. Typical biodiesel yields varied from 83 to nearly 100% with methyl esters content ranging from 1.41–1.66 mol·L and typical dynamic viscosities of 22.1-8.2 cP. Gas chromatography was used to determine the molecular composition of the biodiesel. The reaction products contained over 82 wt-% methyl esters, 4.2 wt-% free acids, 13.5 wt-% monoglycerides, and 0.3 wt-% diglycerides. The transesterification of WFO with methanol around its critical temperature combined with a zeolite Y as an acid catalyst is an efficient approach for the production of biodiesel with acceptable yields.

关键词： biodiesel     methanol     critical temperature     waste frying oil     zeolite Y    

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The role of lipids in fermentative propionate production from the co-fermentation of lipid and food waste

《环境科学与工程前沿（英文）》 2023年 第17卷 第7期 doi: 10.1007/s11783-023-1686-0

摘要：

● Lipid can promote PA production on a target from food waste.

关键词： Acidogenic fermentation     Microbial community     Volatile fatty acid     Propionate     Food waste     Lipid    

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Potential hybrid feedstock for biodiesel production in the tropics

Solomon GIWA,Oludaisi ADEKOMAYA,Collins NWAOKOCHA

《能源前沿（英文）》 2016年 第10卷 第3期   页码 329-336 doi: 10.1007/s11708-016-0408-8

摘要： Recently, mixture of different oils at various proportions have been used as feedstock for biodiesel production. The primary aim is to improve fuel properties which are strongly influenced by the fatty acid composition of the individual oil that makes up the feedstock mix. The tropics are renowned for abundant oil-bearing crops of which palm kernel oil (PKO) from palm seed and groundnut oil (GNO) are prominent. This present paper investigated biodiesel production from hybrid oil (HO) of PKO (medium carbon chain and highly saturated oil) and GNO (long carbon chain and highly unsaturated oil) at 50/50 (v/v) blending. The principal fatty acids (FAs) in the HO are oleic (35.62%) and lauric acids (24.23%) with 47.80% of saturated FA and 52.26% of unsaturated FA contents. The chemical conversion of the oil to methyl ester (ME) gave 86.56% yield. Fuel properties of hybrid oil methyl ester (the HOME) were determined in accordance with standard test methods and were found to comply with both ASTM D6751 and EN 14214 standards. The oxidative stability, cetane number and kinematic viscosity (KV) of HOME were observed to be improved when compared with those of GNO methyl ester from single parent oil, which could be accredited to the improved FA composition of the HO. The KV (3.69 mm /s) of HOME obtained in this paper was remarkably low compared with those reported in literature for most biodiesels. This value suggests better flow, atomization, spray and combustion of this fuel. Conclusively, the binary blend of oils can be a viable option to improve the fuel properties of biodiesel feedstock coupled with reduced cost.

关键词： groundnut oil     palm kernel oil     methyl ester     fuel properties     tropics     fatty acid composition    

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Profiling influences of gene overexpression on heterologous resveratrol production in

Duo Liu,Bingzhi Li,Hong Liu,Xuejiao Guo,Yingjin Yuan

《化学科学与工程前沿（英文）》 2017年 第11卷 第1期   页码 117-125 doi: 10.1007/s11705-016-1601-3

摘要： Metabolic engineering of heterologous resveratrol production in faces challenges as the precursor L-tyrosine is stringently regulated by a complex biosynthetic system. We overexpressed the main gene targets in the upstream pathways to investigate their influences on the downstream resveratrol production. Single-gene overexpression and DNA assembly-directed multigene overexpression affect the production of resveratrol as well as its precursor -coumaric acid. Finally, the collaboration of selected gene targets leads to an optimal resveratrol production of 66.14±3.74 mg·L , 2.27 times higher than the initial production in YPD medium (4% glucose). The newly discovered gene targets expressing phosphoribosylanthranilate isomerase, expressing 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase, and expressing 4-coumaryl-CoA ligase show notable positive impacts on resveratrol production in .

关键词： resveratrol     aromatic amino acid     DNA assembly     metabolic engineering     gene overexpression    

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标题 作者 时间 类型 操作

High production of butyric acid by

Chao Ma,Jianfa Ou,Matthew Miller,Sarah McFann,Xiaoguang (Margaret) Liu

期刊论文

Continuous biohydrogen production from diluted molasses in an anaerobic contact reactor

Sheng CHANG, Jianzheng LI, Feng LIU

期刊论文

Genomic and metabolomic analysis of with enhanced poly--glutamic acid production through atmospheric

期刊论文

Biodiesel production by the transesterification of cottonseed oil by solid acid catalysts

CHEN He, PENG Baoxiang, WANG Dezheng, WANG Jinfu

期刊论文

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

期刊论文

Factors affecting production of nonaqueous peracetic acid in tubular packed reactors

ZHANG Tengyun, FAN Hongbo, ZHONG Li, CHUANG Karl

期刊论文

Use of dry yeast cells as a cheap nitrogen source for lactic acid production by thermophilic

Kim Yng Ooi, Jin Chuan Wu

期刊论文

Enhanced production of

Shen Huang,Xudong Feng,Chun Li

期刊论文

Synthesis of magnetic carbonaceous acid derived from waste garlic peel for biodiesel production via esterification

Hewei YU, Jinke WU, Wei WEI, Xingyu ZHANG, Changzai REN, Yaoqi DONG, Shen CHENG

期刊论文

A pulsed switching peroxi-coagulation process to control hydroxyl radical production and to enhance 2,4-Dichlorophenoxyacetic acid degradation

Yaobin Lu, Songli He, Dantong Wang, Siyuan Luo, Aiping Liu, Haiping Luo, Guangli Liu, Renduo Zhang

期刊论文

Statistical modeling and optimization for enhanced hyaluronic acid production by batch culture of Sreptococcus

Long LIU, Haiquan YANG, Guocheng DU, Miao WANG, Jian CHEN,

期刊论文

Biodiesel production from waste frying oil in sub- and supercritical methanol on a zeolite Y solid acid

Jorge MEDINA-VALTIERRA, Jorge RAMIREZ-ORTIZ

期刊论文

The role of lipids in fermentative propionate production from the co-fermentation of lipid and food waste

期刊论文

Potential hybrid feedstock for biodiesel production in the tropics

Solomon GIWA,Oludaisi ADEKOMAYA,Collins NWAOKOCHA

期刊论文

Profiling influences of gene overexpression on heterologous resveratrol production in

Duo Liu,Bingzhi Li,Hong Liu,Xuejiao Guo,Yingjin Yuan

期刊论文