Advances in biotransformation of methanol into chemicals / 生物工程学报

Methanol has become an attractive substrate for the biomanufacturing industry due to its abundant supply and low cost. The biotransformation of methanol to value-added chemicals using microbial cell factories has the advantages of green process, mild conditions and diversified products. These advantages may expand the product chain based on methanol and alleviate the current problem of biomanufacturing, which is competing with people for food. Elucidating the pathways involving methanol oxidation, formaldehyde assimilation and dissimilation in different natural methylotrophs is essential for subsequent genetic engineering modification, and is more conducive to the construction of novel non-natural methylotrophs. This review discusses the current status of research on methanol metabolic pathways in methylotrophs, and presents recent advances and challenges in natural and synthetic methylotrophs and their applications in methanol bioconversion.

Advances in the metabolic engineering for the production of tetracarbon organic acids / 生物工程学报

Tetracarbon organic acids are important platform chemicals that are widely used in the food, chemical, medicine, material industries and agriculture. Compared with the traditional petrochemical process, the production of tetracarbon organic acids by microbial fermentation is more promising due to milder reaction conditions, greener process and better environmental compatibility. This review summarizes the biosynthetic pathways and metabolic mechanisms for the production of tetracarbon organic acids, and illustrates recent advances, challenges, and future perspectives in the production of tetracarbon organic acids by naturally selected or purposefully engineered strains.

Bio-based molecules for biosynthesis of nano-metallic materials / 生物工程学报

Nano-metallic materials are playing an important role in the application of medicine, catalysis, antibacterial and anti-toxin due to their obvious advantages, including nanocrystalline strengthening effect, high photo-absorptivity, high surface energy and single magnetic region performance. In recent years, with the increasing consumption of global petrochemical resources and the aggravation of environmental pollution, nanomaterials based on bio-based molecules have aroused great concern. Bio-based molecules refer to small molecules and macromolecules directly or indirectly derived from biomass. They usually have good biocompatibility, low toxicity, degradability, wide source and low price. Besides, most bio-based molecules have unique physical, chemical properties and physiological activity, such as optical activity, acid/alkali amphoteric property, hydrophilic property and easy coordination with metal ions. Thus, the corresponding nano-materials based on bio-based molecules also have unique functions, such as anti-inflammatory, anti-cancer, anti-oxidation, antiviral fall blood sugar and blood fat etc. In this paper, we give a comprehensive overview of the preparation and application of nano-metallic materials based on bio-based molecules in recent years.

Advances in the synthesis of biobutanol by consolidated bioprocessing from lignocellulose / 生物工程学报

Consolidated bioprocessing (CBP) is a multi-step process in a bioreactor, which completes hydrolase production, enzymatic hydrolysis, and microbial fermentation. It is considered to be the most promising process for the production of second-generation biofuels because of its simple steps and low cost. Due to the complexity of lignocellulose degradation and the butanol synthesis pathway, few wild microorganisms can directly utilize lignocellulose to synthesize butanol. With the development of synthetic biology, single-bacterium directly synthesizes butanol using lignocellulose by introducing a butanol synthesis pathway in the cellulolytic Clostridium. However, there are still some problems such as heavy metabolic load of single bacterium and low butanol yield. Co-culture can relieve the metabolic burden of single bacterium through the division of labor in different strains and can further improve the efficiency of butanol synthesis. This review analyzes the recent research progress in the synthesis of biobutanol using lignocellulose by consolidated bioprocessing from both the single-bacterium strategy and co-culture strategy, to provide a reference for the research of butanol and other biofuels.

Expression, purification and characterization of N-glycanase from Schizosaccharomyces pombe in Escherichia coli / 生物工程学报

One pair of primers were designed and synthesized on the base of the cDNA sequence encoding Schizosaccharomyces pombe N-glycanase reported on the GenBank. The cDNA sequence encoding Peptide N-glycanase was cloned from the Schizosaccharomyces pombe by RT-PCR. And then the RT-PCR product was cloned into the expression vector pET-15b. The expression vector pET-15b(+)/Png1p was transformed into E. coli BL21(DE3). The results showed that the relative molecular weight of the enzyme was determined to be approximately 39 kD using SDS-PAGE. The expression products after induction and purification can catalyze the cleavage of N-linked oligosaccharides from glycoprotein coped with heat, but have no action on the native glycoprotein with the help of DTT. The percentage of deglycosylated RNase B treated with equate Png1p in different reaction temperature, pH, concentration of DTT and denatured temperature showed that the optimum temperature, the optimum pH is 30 degrees C; the optimum concentration of DTT is 10 mmol/L and the optimum denatured temperature is 100 degrees C.