ENERGY & FUELS
·
2023
·
IF 5.3
Zhihui Ling,Shang Wang,Zhongzhan Leng,Chengmei Li,Wenhui Zhang,Xinxin Kang,Xianghui Qi,Cunsheng Zhang
To improve the performance of ethanol production from food waste, a consolidation process involving both the addition of surfactant and cell immobilization was investigated. Results showed that the optimum glucose concentration was 200 g/L for ethanol fermentation using Saccharomyces cerevisiae as inoculum. With the addition of 0.5% Tween 80, the ethanol production was improved from 68.1 to 79.8 g/L, which was attributed to the increased mass transfer of cells provoked by Tween 80. In a cell-immobilized system, wheat straw was used as the matrix to carry the cells. A high ethanol production of 87.8 g/L was obtained with the sequential fermentation mode due to the high cell density on the cell carrier. The results of a mass balance calculation revealed that the ethanol production of food waste achieved 340.4 kg/t (on a dry basis), which provided an insight that food waste was a suitable substrate for ethanol production. The main cost was spent on energy consumption in the processes of food waste sterilization, hydrolysis, fermentation, and ethanol distillation, and measures for reducing the energy were suggested to improve the economic performance of ethanol production.
研究领域:
生物技术
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环境科学
·
发酵工程
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产品关联
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 12
·1911
·
IF 4.7
Le Wang,Jianguang Liu,Yan Shen,Yanli Yin,Zifu Ni,Jun Xi,Yuansen Hu,Qipeng Yuan
The preparation of a novel composite carrier of polydopamine-modified carbon fiber/polyurethane foam (PDA-CF/PUF) was proposed to improve cell immobilization and the fermentation of xylitol, which is an important food sweetener and multifunctional food additive.Candida tropicaliswas immobilized on the composite carrier by adsorption and covalent binding. The properties and immobilization mechanism of the composite carrier and its effect on immobilized cells were investigated. It showed that the modification of PDA enhanced the loading of CF on the PUF surface and the adhesion of cells on the composite carrier surface. Also, the biocompatibility of carriers to cells was improved. In addition, the introduction of PDA increased the active groups on the surface of the carrier, enhanced the hydrophilicity, promoted the cells immobilization, and increased the xylitol yield. It was also found that expression of the related gene XYL1 in cells was significantly increased after the immobilization of the PDA-CF/PUF composite carrier during the fermentation. The PDA-CF/PUF was an immobilized carrier with the excellent biocompatibility and immobilization performance, which has great development potential in the industrial production of xylitol.
研究领域:
生物技术
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食品科学
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产品关联
DOI
PubMed
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2023
·
IF 4.3
Wei Liu,Wei Zha,Hao Yin,Chunyan Yang,Ke Lu,Jianxin Chen
The objective of this work was to promote biobutanol production by integrating rare earth element stimulation, activated carbon adsorption and cell immobilization into acetone-butanol-ethanol fermentation. Among eight selected rate earth elements, the trace supplement of gadolinium (Gd(III)) into fermentation medium (1 × 10 −5 M) could significantly stimulate cell growth and biobutanol biosynthesis. Subsequently, activated carbon particles had been used to alleviate biobutanol toxic effect for bacterial cells. The adsorption of biobutanol on activated carbon particles was coincident with Pseudo-first-order dynamics and Freundlich isotherm models. In order to prevent the competitive adsorption between bacterial cells and biobutanol on activated carbon particles, bacterial cells bad been immobilized on the surface of volcanic stones. After cultivating for 5 h, activated carbon particles were introduced into fermentation broth for performing biobutanol isolation. Finally, the total biobutanol yield using the developed strategy was 15.26 ± 0.43 g/L, which was 73.20 ± 12.69% higher than that of common fermentation with free bacterial cells.
研究领域:
微生物学
·
生物工程
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DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 4
·645-650
·
IF 0.875
Geng Zhi,Zhu Suiyi,Yu Yang,Lu Ying,Lin Rao,Guo Shujun,Bian Dejun,Yang Xia,Huo Mingxin,Huo Hongliang
Novel matrix beads for the immobilization of strain Comamonas testosteroni sp. bdq06 to degrade quinoline were fabricated from polyethersulfone(PES). The beads have an average size of 3 mm and a surface dense layer of 20 microns. To help adhesion and proliferation of bacterial cells, the surfaces of the PES beads were etched, and numerous holes about 1.5 micrometers in diameter were generated as tunnels for cell colonizing in the larger internal cavities of about 5 micrometers in diameter. The quinoline degradation was remarkably enhanced by the cells immobilized in PES beads compared with that by the free cells at pH 5.0 or 10.0 and a temperature of 40 °C. The enhanced degradation of quinoline was contributed to the biofilm on the surface of PES beads, resulting in the significant reduction of retention time from 9 h to 2 h. Furthermore, the beads remain intact after the ultrasonic treatment of them for 30 min or recycling 50 times, indicating that they have excellent mechanical strength, flexibility and swelling capacity. Thus, PES beads have great potential to be matrix for the cell immobilization in bioaugmentation.
研究领域:
环境生物学
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微生物学
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产品关联
DOI
高影响因子
MATERIALS SCIENCE FORUM
·
2020
·
IF 0
Yuan Lu,Hong Qian Dai,Zhi Min Ou
The magnetic ferroferric oxide nanoparticles were modified with L-lysine to prepare immobilized carriers(Fe3O4-Lys), which was applied to the immobilization of Saccharomyces cerevisiae CGMCC No. 2230. The optimal immobilization conditions for preparation of Fe3O4-Lys-Cells were Fe3O4-Lys 0.01 g, cell dry weight 3 g, pH 7, 3 h, 30 °C. Ethyl R-4-chloro-3-hydroxybutyrate was gained by asymmetric reduction of ethyl-4-chlorooxobutanoate with Fe3O4-Lys-Cells as catalysis. 0.672 mol/L COBE can be converted completely in 40 h in the shaker, while only 24 h in the alternating magnetic field. The conversion and enantiomeric excess(e.e.) of (R)-CHBE reached 100% and more than 99.9%, respectively.
研究领域:
生物化学
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纳米生物学
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酶工程
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DOI
Frontiers in Bioengineering and Biotechnology
·
2020
·
IF 3.644
Peng Fei,Su Hui-Hui,Ou Xiao-Yang,Ni Zi-Fu,Zong Min-Hua,Lou Wen-Yong
(R)-1-phenyl-1,2-ethanediol is an important synthon for the preparation of β-adrenergic blocking agents. This study identified a (2R,3R)-butanediol dehydrogenase (KgBDH) from Kurthia gibsonii SC0312, which showed high enantioselectivity for production of (R)-1-phenyl-1,2-ethanediol by reduction of 2-hydroxyacetophenone. KgBDH was expressed in a recombinant engineered strain, purified, and characterized. It showed good catalytic activity at pH 6–8 and better stability in alkaline (pH 7.5–8) than an acidic environment (pH 6.0–7.0), providing approximately 73 and 88% of residual activity after 96 h at pH 7.5 and 8.0, respectively. The maximum catalytic activity was obtained at 45°C; nevertheless, poor thermal stability was observed at >30°C. Additionally, the examined metal ions did not activate the catalytic activity of KgBDH. A recombinant Escherichia coli strain coexpressing KgBDH and glucose dehydrogenase (GHD) was constructed and immobilized via entrapment with a mixture of activated carbon and calcium alginate via entrapment. The immobilized cells had 1.8-fold higher catalytic activity than that of cells immobilized by calcium alginate alone. The maximum catalytic activity of the immobilized cells was achieved at pH 7.5, and favorable pH stability was observed at pH 6.0–9.0. Moreover, the immobilized cells showed favorable thermal stability at 25–30°C and better operational stability than free cells, retaining approximately 55% of the initial catalytic activity after four cycles. Finally, 81% yields (195 mM product) and >99% enantiomeric excess (ee) of (R)-1-phenyl-1,2-ethanediol were produced within 12 h through a fed-batch strategy with the immobilized cells (25 mg/ml wet cells) at 35°C and 180 rpm, with a productivity of approximately 54 g/L per day.
研究领域:
生物化学
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酶工程
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合成生物学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Edidiong Okokon Atakpa,Hanghai Zhou,Lijia Jiang,Dongdong Zhang,Yanhong Li,Wenjie Zhang,Chunfang Zhang
The widespread exploration and exploitation of crude oil has increased the prevalence of petroleum hydrocarbon pollution in the marine and coastal environment. Bioremediation of petroleum hydrocarbons using cell immobilization techniques is gaining increasing attention. In this study, the crude oil degradation performance of bacterial and fungal co-culture was optimized by entrapping both cells in sodium-alginate and polyvinyl alcohol composite beads. Results indicate that fungal cells remained active after entrapment and throughout the experiment, while bacterial cells were non-viable at the end of the experimental period in treatments with the bacterial-fungal ratio of 1:2. A remarkable decrease in surface tension from 72 mN/m to 36.51 mN/m was achieved in treatments with the bacterial-fungal ratio of 3:1. This resulted in a significant ( P < 0.05 ) total petroleum hydrocarbon (TPH) removal rate of 89.4%, and the highest degradation of n -alkanes fractions (from 2129.01 mg/L to 118.53 mg/L), compared to the other treatments. Whereas PAHs removal was highest in treatments with the most fungal abundance (from 980.96 μg/L to 177.3 μg/L). Furthermore, enzymes analysis test revealed that catalase had the most effect on microbial degradation of the target substrate, while protease had no significant impact on the degradation process. High expression of almA and PAH-RHDa genes was achieved in the co-culture treatments, which correlated significantly ( P < 0.05 ) with n -alkanes and PAHs removal, respectively. These results indicate that the application of immobilized bacterial and fungal cells in defined co-culture systems is an effective strategy for enhanced biodegradation of petroleum hydrocarbons in aqueous systems.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
Catalysts
·
2023
·Vol. 13
·期 2
·371
·
IF 3.9
Xue-Jiao Liu,Bao-Di Ma,Xiao-Mei Wu,Yi Xu
A recombinantE. coli, expressing nitrilase fromAcidovorax facilis72W with dual-site expression plasmid pRSFduet (E. colipRSF-AfNit2), was constructed. It showed higher soluble expression of nitrilase than that in the pET21a plasmid. The recombinant nitrilase can efficiently catalyze the hydrolysis of 3-cyanopyridine to nicotinic acid. The whole cells ofE. colipRSF-AfNit2 were immobilized by using sodium alginate/glutaraldehyde/polyethylene imine as the best immobilized reagents. The immobilized cells showed 95% activity recovery and excellent mechanical strength, with improved thermal stability and pH stability. They also retained 82% of initial activity after nearly two months of storage at 4 °C. A semi-continuous packed-bed bioreactor (sPBR) filled with the immobilized cells was studied for efficient production of nicotinic acid. After optimization, the highest space–time yield of 1576 g/(L·d) was obtained on 0.8 M substrate concentration at 2 mL/min of flow rate. The sPBR was repeatedly operated for 41 batches, keeping 100% conversion in the presence of 30 mM CaCl2. Finally, 95 g of nicotinic acid were obtained at 90% yield after separation and purification. The developed technology has potential application value.Keywords:nitrilase;cell immobilization;nicotinic acid;reaction optimization;semi-continuous packed-bed bioreactor
研究领域:
生物技术
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生物化工
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微生物学
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产品关联
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 2.467
Jiajiang Lin,Li Gan,Zuliang Chen,Ravendra Naidu
Immobilized cells present advantages for degrading organic pollutants compared to free suspended cells. However, the immobilization of cells with reference to agricultural waste is still limited. This study investigated using bagasse as a carrier to immobilize Acinetobacter venetianus ( A. venetianus ) for the degradation of n -alkane. The degradation of alkane based on both adsorption and biodegradation by immobilized A. venetianus was observed, where 93.3%, 77.7% and 24.0% of tetradecane (400 mg L −1 ) were removed by the immobilized cells, free cells and bagasse after 36 h incubation, respectively. Additionally, alkane (C 10 –C 25 ) in diesel was effectively degraded by the immobilized cells, of which 800 mg L −1 of alkane was completely degraded after 60 h. Furthermore, results showed: (1) tetradecane served as the optimal carbon source at the concentration of 100 mg L −1 ; and (2) cells immobilization reached its peak efficiency with the cells-to-bagasse ratio of 0.5 mg cell g −1 bagasse . Cells strongly immobilized on bagasse retained a high degradation rate of 77.6% after shaking at 1500 rpm. Bagasse protected the cells from pollution stress including cadmium (Cd(II)) and phenanthrene. After 8 reuse cycles, immobilized cells became more stable and efficient. Bagasse- A. venetianus has potential for future application in remediating diesel contaminants.
研究领域:
环境生物学
·
微生物学
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产品关联
DOI
高影响因子
Microbial Cell Factories
·
2022
·Vol. 21
·期 1
·1-13
·
IF 6.352
Zhong Zhi-Hao,Zhang Yu-Qing
Background The immobilized technology for microbial or cells has the advantages of high microbial activity, high microbial density per unit space, good tolerance, strong shock, load resistance, high processing efficiency, and high reuse rate. It is now widely used in environmental remediation, water quality treatment, biodegradation, food industry, chemical analysis, energy development, medicine and pharmaceuticals, and other fields.Results A novel Escherichia coli cell-immobilizing polyvinyl alcohol hydrogel membrane (ECI-PVAHM) was prepared by unidirectional nanopore dehydration (UND) from a 10% polyvinyl alcohol (PVA) aqueous solution containing enhanced green fluorescent protein-labeled E. coli. This bacteria-loaded film has high water stability, flexibility, transparency, and mechanical robustness. Its tensile strength, elongation rate, and swelling rate are in the ranges 0.66–0.90 MPa, 300–390%, and 330–800%, respectively. The effective bacterial load of ECI-PVAHM is 2.375 × 109–1010 CFU/g (dry weight), which does not affect the original crystal structure of the PVAHM. This biofilm has a porous network structure with pore sizes between 0.2 and 1.0 μm, and these cells are embedded in the PVAHM network. When the immobilized cells were continuously cultured for 20 days, and the medium was renewed twice daily, their relative proliferation efficiency after 40 cycles could still be maintained at ~ 91%.Conclusion The above results show that the cell division, proliferation ability, and metabolic activity of immobilized E. coli were not affected by the physical barrier of the porous network structure of the hydrogel. This UND-based ECI-PVAHM has potential applications in molecular biology, biopharmaceutical expression and production, bioreactors, and fuel cells.
研究领域:
生物技术
·
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY
·
2015
·Vol. 42
·期 2
·189-196
·
IF 2.439
Zhu Deyi,Li Xia,Liao Xuepin,Shi Bi
Collagen fiber (CF), an abundant natural biopolymer, features many favorable properties that make it a potential carrier for cell immobilization. In the present investigation, CF was grafted with polyethyleneimine (PEI) using glutaraldehyde (GA) as the cross-linking agent, resulting in the formation of a novel CF based carrier (CF-PEI). The properties of CF-PEI as a carrier were evaluated by the immobilization of Microbacterium arborescens (CICC 20196), which has glucose isomerase (EC 5.3.1.5) activity. It was found that M. arborescens cells immobilized on CF-PEI exhibited higher glucose isomerization than those using activated carbon or anion exchange resin as the carriers. The Michaelis constant (K m) of the isomerization reaction for the CF-PEI-immobilized M. arborescens cells was 0.528 mol/L, which was slightly higher than that of free cells (0.473 mol/L). In addition, the apparent activation energies (E a) of free and immobilized cells on CF-PEI were almost the same at 60 kJ/mol. In an isomerization reaction of glucose to fructose in a fixed-bed reactor, CF-PEI-immobilized M. arborescens cells showed appreciable activity and operational stability. The corresponding isomerization ratio was as high as 41 % for 20 days, and the half-life was about 40 days.
研究领域:
生物技术
·
生物工程
·
酶技术
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DOI
PubMed
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2023
·Vol. 46
·期 8
·1175-1194
·
IF 3.8
Liu Siyuan,Liu Wei,Yin Hao,Yang Chunyan,Chen Jianxin
This work focused on the development of an inexpensive carbon source and the improvement of the fermentation-foam fractionation coupling system. The rhamnolipids production capacity of waste frying oil (WFO) was evaluated. The suitable bacterial cultivation of seed liquid and the addition amount of WFO was 16 h and 2% (v/v), respectively. A combined strategy of cell immobilization and oil emulsion avoid cell entrainment inside foam and improves the oil mass transfer rate. The immobilization conditions of bacterial cells into alginate-chitosan-alginate (ACA) microcapsules were optimized using the response surface method (RSM). Under the optimal conditions, rhamnolipids production using batch fermentation with immobilized strain reached 7.18 ± 0.23% g/L. WFO was emulsified into a fermentation medium using rhamnolipids as emulsifier (0.5 g/L). By monitoring dissolved oxygen, 30 mL/min was selected as a suitable air volumetric flow rate for fermentation-foam fractionation coupling operation. The total production and recovery percentage of rhamnolipids were 11.29 ± 0.36 g/L and 95.62 ± 0.38%, respectively. Graphical abstract
研究领域:
生物技术
·
环境工程
·
化学工程
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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）