Chuang Xue

Dalian University of Technology | DUT · School of Life Science and Biotechnology

Serine/threonine protein kinases (STKs) are important for signal transduction and involved in multiple physiological processes, including cell growth, central metabolism, and sporulation in bacteria. However, the role of STKs in solventogenic clostridia remains unclear. Here, we identified and comprehensively investigated six STK candidates in Clos...

Feedback inhibition is one of the main challenges of fermentative hydrogen production. In this study, the effects of butyrate and acetate on hydrogen production of Clostridium tyrobutyricum were investigated. Substrate consumption and hydrogen production were accelerated when acetate ≤15 g/L was fed. Exogenous acetate induced acetate assimilation a...

Biobutanol is naturally produced by solventogenic clostridia during acetone-butanol-ethanol (ABE) fermentation, which is hampered by low butanol titer, yield and productivity. Here, Clostridium acetobutylicum ATCC 55025 and its robust mutant HKKO with histidine kinase genes cac3319/cac0323 knockout were metabolically engineered to eliminate acetone...

Anaerobic, non-photosynthetic mixotrophy (ANP mixotrophy) is a process whereby glucose consumption and CO2 fixation via the Wood-Ljungdahl pathway occur concurrently. ANP mixotrophy supplemented with exogenous reducing power and CO2 shows the potential of reducing the carbon loss from glycolysis and enhancing the production of biofuels. Previous st...

Solventogenesis and sporulation of clostridia are the main responsive adaptations to the acidic environment during acetone‐butanol‐ethanol (ABE) fermentation. It was hypothesized that five orphan histidine kinases (HKs) including Cac3319, Cac0323, Cac0903, Cac2730 and Cac0437 determined the cell fates between sporulation and solventogenesis. In thi...

Butanol production by solventogenic clostridia has long been complicated with the formation of acetone as a main byproduct, which causes a low product yield. Here, although some recent attempts failed to engineer the hydrogenase gene hydA in wild-type Clostridium, we successfully disrupted hydA with a plasmid pSY6 in C. acetobutylicum ATCC 55025. T...

Microorganisms harbor bulks of functionally similar or undefined genes, which belong to paralogous gene family. There is a necessity of exploring combinatorial or interactive functions of these genes, but conventional loss‐of‐function strategy with one‐by‐one rounds suffers extremely low efficiency for generating mutant library with all genes permu...

Simultaneous saccharification and fermentation (SSF) is a widely used approach for lignocellulosic butanol production. However, the major drawbacks for SSF lie in poor cellulase activity, sugar yield and butanol productivity at temperature below 37 °C. For the first time, a genetically engineered Clostridium acetobutylicum with enhanced thermotoler...

Hybrid materials based on carbon nanotubes (CNTs) and polymers have shown attractive properties and potential applications. However, the poor quality and aggregation of CNTs are challenging during the preparation of hybrid materials. To address these issues, we fabricated the vertically aligned (VA) CNT (open-end) hybrid membrane with annealing tre...

In this study, spray-coating was used to prepare dihydroxypolydimethylsiloxane (PDMS) composite membranes with high flux and separation factor for biobutanol recovery from aqueous solution. A thin, smooth, and defect-free PDMS layer was prepared by spray-coating on polyvinylidene difluoride (PVDF) ultrafiltration membrane with little PDMS penetrati...

Biobutanol, as an advanced biofuel substitute, is reviving via microbial acetone-butanol-ethanol (ABE) fermentation. However, this biochemical process compromises low butanol production and productivity from glucose as the most abundant carbon source in biomass. In this study, three glucose-specific PTS-encoding genes glcG, CAC1353 and CAC1354 in C...

Clostridium beijerinckii, a promising industrial microorganism for butanol production, suffers from low butanol titer and lack of high-efficiency genetical engineering toolkit. A few histidine kinases (HKs) responsible for Spo0A phosphorylation have been demonstrated as functionally important components in regulating butanol biosynthesis in solvent...

Background: Corn stover (CS) is evaluated as the most favorable candidate feedstock for butanol production via microbial acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum. By independent acid pretreatment and enzymatic hydrolysis, fermentable sugars (mainly glucose and xylose) were released, of which glucose was naturally ut...

As the initial step in carbohydrate catabolism in cells, the substrate-specific transporters via active transport and facilitated diffusion play a decisive role in passage of sugars through the plasma membrane into the cytoplasm. The SecY complex (SecYEG) in bacteria forms a membrane channel responsible for protein translocation. This work demonstr...

Background Butanol derived from renewable resources by microbial fermentation is considered as one of not only valuable platform chemicals but alternative advanced biofuels. However, due to low butanol concentration in fermentation broth, butanol production is restricted by high energy consumption for product recovery. For in situ butanol recovery...

Jerusalem artichoke (JA) can grow well in marginal lands with high biomass yield, and thus is a potential energy crop for biorefinery. The major biomass of JA is from tubers, which contain inulin that can be easily hydrolyzed into a mixture of fructose and glucose, but fructose utilization for producing butanol as an advanced biofuel is poor compar...

Background Butanol as an important chemical and potential fuel could be produced via ABE fermentation from lignocellulosic biomass. The use of food-related feedstocks such as maize and sugar cane may not be a sustainable solution to world’s energy needs. Recently, Jerusalem artichoke tubers containing inulin have been used as feedstock for butanol...

Butanol as an advanced biofuel has gained great attention due to its environmental benefits and superior properties compared to ethanol. However, the cost of biobutanol production via conventional acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum is not economically competitive, which has hampered its industrial application....

Butanol is considered as an advanced biofuel, the development of which is restricted by the intensive energy consumption of product recovery. A novel two-stage gas stripping-pervaporation process integrated with acetone-butanol-ethanol (ABE) fermentation was developed for butanol recovery, with gas stripping as the first-stage and pervaporation as...

Clostridium acetobutylicum JB200, a mutant strain of C. acetobutylicum ATCC 55025 obtained through strain evolution in a fibrous bed bioreactor, had high butanol tolerance and produced up to ~21 g/L butanol from glucose in batch fermentation, an improvement of ~67 % over the parental strain (~12.6 g/L). Comparative genomic analysis revealed a singl...

The polydimethylsiloxane-polyvinylidene fluoride (PDMS-PVDF) composite membrane was studied for its pervaporation performance to removal of butanol from butanol/ABE solution, fermentation broth as well as incorporated with acetone-butanol-ethanol (ABE) fermentation. The total flux and butanol titer in permeate through the PDMS-PVDF membrane were up...

The carbon nanotubes (CNTs) filled polydimethylsiloxane (PDMS) hybrid membrane was fabricated to evaluate its potential for butanol recovery from acetone-butanol-ethanol (ABE) fermentation broth. Compared with the homogeneous PDMS membrane, the CNTs filled into the PDMS membrane were beneficial for the improvement of butanol recovery in butanol flu...

Butanol has recently gained increasing interest due to escalating prices in petroleum fuels and concerns on the energy crisis. However, the butanol production cost with conventional acetone-butanol-ethanol fermentation by Clostridium spp. was higher than that of petrochemical processes due to the low butanol titer, yield, and productivity in biopro...

Process oscillation is the main challenge in continuous very high gravity （VHG） ethanol fermentation, which could result in oscillation and decrease of ethanol concentration. In the present study, during continuous VHG ethanol fermentation by free cell Saccharomyces cerevisiae 4126 and self- flocculating yeast BHL01, sustained process oscillations...

VHG fermentation is a promising process engineering strategy aiming at improving ethanol titer, and thus saving energy consumption for ethanol distillation and distillage treatment. However, sustained process oscillation was observed during continuous VHG ethanol fermentation, which significantly affected ethanol fermentation performance of the sys...

Butanol has been acknowledged as an advanced biofuel, but its production through acetone-butanol-ethanol (ABE) fermentation by Clostridia is still not economically competitive, due to low butanol yield and titer. In this article, updated progress in butanol production is reviewed. Low price and sustainable feedstocks such as lignocellulosic residue...

In this article, effect of zinc supplementation on acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum was studied. It was found that when 0.001g/L ZnSO4·7H2O was supplemented into the medium, solventogenesis was initiated earlier, with 21.0g/L ABE (12.6g/L butanol, 6.7g/L acetone and 1.7g/L ethanol) produced with a fermentatio...

Two-stage gas stripping coupled with acetone-butanol-ethanol fermentation in a fibrous bed bioreactor was established for energy-efficient butanol recovery. The impact of process parameters including butanol concentration, temperature and cell density with feed, gas flow rate, and cooling temperature on the efficiency of the gas stripping system wa...

Acetone-butanol-ethanol (ABE) fermentation with a hyper-butanol producing Clostridium acetobutylicum JB200 was studied for its potential to produce a high titer of butanol that can be readily recovered with gas stripping. In batch fermentation without gas stripping, a final butanol concentration of 19.1 g/L was produced from 86.4 g/L glucose consum...

Acetone–butanol–ethanol (ABE) fermentation with a hyper‐butanol producing Clostridium acetobutylicum JB200 was studied for its potential to produce a high titer of butanol that can be readily recovered with gas stripping. In batch fermentation without gas stripping, a final butanol concentration of 19.1 g/L was produced from 86.4 g/L glucose consum...

Taking continuous ethanol fermentation with the self-flocculating yeast SPSC01 under very high concentration conditions as an example, the fermentation performance of the yeast flocs and their metabolic flux distribution were investigated by controlling their average sizes at 100, 200, and 300 microm using the focused beam reflectance online measur...

High ethanol tolerance is a desired property of industrial yeast strains for efficient ethanol fermentation. In this study, the impact of medium composition on ethanol tolerance of the self-flocculating yeast SPSC01 was investigated using a chemically defined medium. Single-factor experiments revealed that besides magnesium and calcium, zinc also e...

The effects of zinc supplementation were investigated in the continuous ethanol fermentation using self-flocculating yeast. Zinc sulfate was added at the concentrations of 0.01, 0.05 and 0.1 g l(-1), respectively. Reduced average floc sizes were observed in all the zinc-supplemented cultures. Both the ethanol tolerance and thermal tolerance were si...

Ethanol tolerance of self-flocculating yeast SPSC01 was studied in a 3-L bioreactor under fed-batch culture. Yeast floc populations with the average sizes around 100, 200, 300, and 400 microm were obtained by adjusting the mechanical stirring rates of the fermentation system. When subjected to 20% (V/V) ethanol shock for 6 h at 30 degrees C, the re...