The products concentrations in traditional acetone-butanol (AB) fermentation are too low that large amount of energy has to be consumed in the distillation and product recovery process. Aiming at direct utilization of the fermentation products, in this study, optimization of property-improved biodiesel manufacturing process coupled with AB extractive fermentation was conducted, under the condition of using the biodiesel originated from waste cooking oil as the extractant and high concentrated corn flour medium. The effect of biodiesel/broth volume ratio, waste supernatant recycle ratio, and electronic carrier addition on the major process performance index was carefully investigated. Under the optimized condition, the biodiesel quality was improved with the cetane value increased from 51.4 to 54.4; "actual butanol yield" reached to a level of 18%, and waste supernatant recycle ratio exceeded 50%. In this way, elimination of energy-consuming product recovery process and realization of "energy-saving & waste minimization" industrial production target advocated by the state government, could be potentially expected.
Bioelectric Energy Sources ; Butanols ; chemistry ; Fermentation ; Gasoline ; Zea mays ; metabolism

The low butanol concentration of acetone-butanol-ethanol fermentation causes uneconomical product recovery. In this work, the effect of small molecule non-ionic surfactants on butanol fermentation was evaluated, using laboratory stocks of Clostridium acetobutylicum ATCC 824. Non-ionic surfactants substantially increased butanol production when additive amount was higher than 1% (W/W). Butanol concentration reached 16.9 g/L with 5% (W/W) Tween 80 and 100 g/L glucose in a 5 L fermenter. It was found that surfactants micelle solubilization capacity to butanol was very limited, indicating that butanol could hardly enter the surfactants micelle. Butanol production improvement was probably caused by cell surface hydrophobicity change due to surfactants adsorption.
Acetone ; chemistry ; Bioreactors ; Butanols ; chemistry ; Clostridium acetobutylicum ; metabolism ; Ethanol ; chemistry ; Fermentation ; Surface-Active Agents ; chemistry

Butanol production from acid hydrolysate of Jerusalem artichoke juice by Clostridium acetobutylicum L7 was investigated, and it was found that natural components of the hydrolysate were suitable for solvent production with the species. With batch fermentation using the medium containing 48.36 g/L total sugars, 8.67 g/L butanol was produced at 60 h, and the ratio of butanol to acetone to ethanol was 0.58:0.36:0.06, which were similar to the fermentation with fructose as carbon source, but both of these two fermentations were slower than that with glucose as carbon source, indicating the fructose transport of the species might not be effective as that for glucose. When the total sugars of the medium were increased to 62.87 g/L, the residual sugars increased slightly from 3.09 g/L to 3.26 g/L, but butanol production of the fermentation system was improved significantly, with 11.21 g/L butanol produced and the ratio of butanol to acetone to ethanol at 0.64:0.29:0.05, which illustrated that an excess in sugars enhanced the butanol biosynthesis of the species by compromising its acetone production. When the sugar concentration of the medium was further increased, much more sugars were remained unconsumed, making the process economically unfavourable.
Butanols ; metabolism ; Clostridium acetobutylicum ; metabolism ; Fermentation ; Helianthus ; chemistry ; Industrial Microbiology ; methods

Butanol production from corn stover hydrolysates (CSH) with in-situ liquid-liquid extraction was studied to enhance the production and reduce the fermentation cost. Oleyl alcohol was selected as the suitable solvent and added at the initial fermentation time with the ratio of 1:1 (oleyl alcohol: fermentation broth, V/V). Under this condition, butanol and ABE from CSH with 32.1 g/L total sugars were 3.28 and 4.72 g/L, which were 958.1% and 742.9% higher than those of the controls, respectively. Butanol and ABE production from CSH of 49.7 g/L total sugars after detoxification by ion exchange resin D301 coupled with extraction fermentation were 10.34 g/L and 14.72 g/L with an ABE yield of 0.31 g/g (g ABE/g utilized sugar), which were equal to those of glucose and xylose mixture fermentation. The detoxification and extraction fermentation technology of cellulosic butanol production would provide a crucial technical support to the industrialized production of cellulosic butanol.
Butanols ; isolation & purification ; metabolism ; Fatty Alcohols ; chemistry ; Fermentation ; Liquid-Liquid Extraction ; methods ; Plant Stems ; chemistry ; Zea mays ; chemistry

Sugarcane bagasse modified by polyethylenimine (PEI) and glutaraldehyde (GA) was used as a carrier to immobilize Clostridium acetobutylicum XY16 in the process of butanol production. The effects of chemically modified sugarcane bagasse on batch and repeat-batch fermentations were investigated. Batch fermentation was conducted with an addition of 10 g/L modified sugarcane bagasse and 60 g/L glucose, resulting in a high solvent concentration of 21.67 g/L and productivity of 0.60 g/(L x h) with the treatment of 4 g/L PEI and 1 g/L GA. Compared to the fermentations by free cells and immobilized cells on unmodified sugarcane bagasse, the productivity increased 130.8% and 66.7%, respectively. The fibrous-bed bioreactor also maintained a stable butanol production during repeat-batch fermentations, achieving a maximum productivity of 0.83 g/(L x h) with a high yield of 0.42 g/g.
Batch Cell Culture Techniques ; Bioreactors ; Butanols ; metabolism ; Cells, Immobilized ; Cellulose ; metabolism ; Clostridium acetobutylicum ; metabolism ; Fermentation ; Saccharum ; chemistry

For engineering an efficient butanol-producing Escherichia coli strain, many efforts have been paid on the known genes or pathways based on current knowledge. However, many genes in the genome could also contribute to butanol production in an unexpected way. In this work, we used Tn5 transposon to construct a mutant library including 1 196 strains in a previously engineered butanol-producing E. coli strain. To screen the strains with improved titer of butanol production, we developed a high-throughput method for pyruvate detection based on dinitrophenylhydrazine reaction using 96-well microplate reader, because pyruvate is the precursor of butanol and its concentration is inversely correlated with butanol in the fermentation broth. Using this method, we successfully screened three mutants with increased butanol titer. The insertion sites of Tn5 transposon was in the ORFs of pykA, tdk, and cadC by inverse PCR and sequencing. These found genes would be efficient targets for further strain improvement. And the genome scanning strategy described here will be helpful for other microbial cell factory construction.
Butanols ; chemistry ; DNA Transposable Elements ; Escherichia coli ; metabolism ; Fermentation ; Gene Library ; Hydrazines ; Industrial Microbiology ; Mutagenesis ; Open Reading Frames ; Organisms, Genetically Modified ; Polymerase Chain Reaction ; Pyruvic Acid ; chemistry

Lindera erythrocarpa Makino (Lauraceae) is used as a traditional medicine for analgesic, antidote, and antibacterial purposes and shows anti-tumor activity. We studied the effects of Lindera erythrocarpa on the human ether-a-go-go-related gene (HERG) channel, which appears of importance in favoring cancer progression in vivo and determining cardiac action potential duration. Application of MeOH extract of Lindera erythrocarpa showed a dose-dependent decrease in the amplitudes of the outward currents measured at the end of the pulse (I(HERG)) and the tail currents of HERG (I(tail)). When the BuOH fraction and H2O fraction of Lindera erythrocarpa were added to the perfusate, both I(HERG) and I(tail) were suppressed, while the hexane fraction, CHCl3 fraction, and EtOAc fraction did not inhibit either I(HERG) or I(tail). The potential required for half-maximal activation caused by EtOAc fraction, BuOH fraction, and H2O fraction shifted significantly. The BuOH fraction and H2O fraction (100 microgram/mL) decreased gmax by 59.6% and 52.9%, respectively. The H2O fraction- and BuOH fraction-induced blockades of I(tail) progressively decreased with increasing depolarization, showing the voltage-dependent block. Our findings suggest that Lindera erythrocarpa, a traditional medicine, blocks HERG channel, which could contribute to its anticancer and cardiac arrhythmogenic effect.
Animals ; Butanols/chemistry/metabolism ; Ether-A-Go-Go Potassium Channels/*antagonists & inhibitors/metabolism ; Female ; Humans ; Lindera/*chemistry ; Oocytes/cytology/physiology ; Patch-Clamp Techniques ; Plant Extracts/*metabolism ; Potassium Channel Blockers/*metabolism ; Xenopus laevis