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1.
Bioresour Technol ; 397: 130464, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38401811

RESUMO

Microbial CO2 utilization reduces the carbon footprint, providing economic potential. Biochar, rich in minerals and trace metals, can enhance microbial activity. This study investigates poultry litter and switchgrass biochars produced at 350 and 700 °C (PLB350, PLB700, SGB350 and SGB700, respectively) affect CO2 conversion to C2-C6 alcohols and acids by Clostridium muellerianum P21, C. ragsdalei P11 and C. carboxidivorans P7. Fermentations were in 250-mL bottles containing H2:CO2:N2 (60:20:20) shaken at 125 rpm and 37 °C. SGB350 increased alcohol titers by 1.1-2.1 fold, and PLB350 enhanced acid concentrations by 1.2-1.7 fold compared to the control without biochar. About 2.0-3.3 fold more ethanol was formed by strain P11 compared to strains P7 and P21 with SGB350. However, strain P21 produced 2.4-fold more butanol than strain P7 with SGB350, including unique hexanol production. These results highlight the potential of biochar in enhancing C2-C6 alcohol production from CO2, thereby boosting process feasibility.


Assuntos
Butanóis , Dióxido de Carbono , Carvão Vegetal , Ácidos Graxos , Clostridium , Etanol , Fermentação
2.
Bioresour Technol ; 360: 127573, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35792327

RESUMO

Biochar feedstock and production method affects its physicochemical properties and subsequent application. This study investigated the effects of biochar from switchgrass (SGB) and poultry litter (PLB) produced at 350 and 700 °C on alcohol formation using CO:CO2:H2 (40:30:30) by Clostridium carboxidivorans (P7) and C. ragsdalei (P11). Fermentations were performed in 250 mL bottles with a 50 mL working volume at 37 °C. Strains P7 and P11 produced 1.2- to 2.2-fold more alcohol and consumed 1.2- to 1.9-fold more syngas using biochars made at 700 °C compared to 350 °C. Both strains also produced 1.4- to1.9-fold more alcohol with both biochars made at 700 °C compared to control without biochar. Strain P11 produced 1.1- and 1.6-fold more alcohol and fatty acids, respectively, in medium with PLB made at 700 °C compared to strain P7. These results provide guidance towards the selection of biochar type and production temperature to improve syngas fermentation.


Assuntos
Butanóis , Etanol , 1-Butanol , Carvão Vegetal , Clostridium , Fermentação , Gases , Temperatura
3.
Protein Expr Purif ; 108: 62-72, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25659501

RESUMO

This work reports the upstream and downstream process of recombinant human granulocyte colony stimulating factor (rhG-CSF) expressed in Escherichia coli BL21 (DE3)pLysS. The fed batch mode was selected for the maximum output of biomass (6.4g/L) and purified rhG-CSF (136mg/L) under suitable physicochemical environment. The downstream processing steps viz., recovery, solubilization, refolding and concentration were optimized in this study. The maximum rhG-CSF inclusion bodies recovery yield (97%) was accomplished with frequent homogenization and sonication procedure. An efficient solubilization (96%) of rhG-CSF inclusion bodies were observed with 8M urea at pH 9.5. Refolding efficiency studies showed maximum refolding ⩾86% and ⩾84% at 20°C and pH 9 respectively. The renatured protein solution was concentrated, clarified and partially purified (⩾95%) by the cross flow filtration technique. The concentrated protein was further purified by a single step size exclusion chromatography with ⩾98% purity. The characterization of purified rhG-CSF molecular mass as evidenced by SDS-PAGE, western blot and LC/MS analysis was shown to be 18.8kDa. The secondary structure of rhG-CSF was evaluated by the CD spectroscopic technique based on the helical structural components. The biological activity of the purified rhG-CSF showed a similar activity of cell proliferation with the standard rhG-CSF. Overall, the results demonstrate an optimized downstream process for obtaining high yields of biologically active rhG-CSF.


Assuntos
Escherichia coli/metabolismo , Expressão Gênica , Fator Estimulador de Colônias de Granulócitos , Escherichia coli/genética , Fator Estimulador de Colônias de Granulócitos/biossíntese , Fator Estimulador de Colônias de Granulócitos/química , Fator Estimulador de Colônias de Granulócitos/genética , Fator Estimulador de Colônias de Granulócitos/isolamento & purificação , Humanos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação
4.
J Chromatogr A ; 1379: 74-82, 2015 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-25576039

RESUMO

Protein folding-strong cation exchange chromatography (PF-SCX) has been employed for efficient refolding with simultaneous purification of recombinant human granulocyte colony stimulating factor (rhG-CSF). To acquire a soluble form of renatured and purified rhG-CSF, various chromatographic conditions, including the mobile phase composition and pH was evaluated. Additionally, the effects of additives such as urea, amino acids, polyols, sugars, oxidizing agents and their amalgamations were also investigated. Under the optimal conditions, rhG-CSF was efficaciously solubilized, refolded and simultaneously purified by SCX in a single step. The experimental results using ribose (2.0M) and arginine (0.6M) combination were found to be satisfactory with mass yield, purity and specific activity of 71%, ≥99% and 2.6×10(8)IU/mg respectively. Through this investigation, we concluded that the SCX refolding method was more efficient than conventional methods which has immense potential for the large-scale production of purified rhG-CSF.


Assuntos
Cromatografia , Fator Estimulador de Colônias de Granulócitos/química , Proteínas Recombinantes/química , Cátions/química , Escherichia coli/química , Fator Estimulador de Colônias de Granulócitos/isolamento & purificação , Humanos , Técnicas In Vitro , Peso Molecular , Dobramento de Proteína , Ureia/química
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