Zhiqun Liang

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Two novel β-glucosidases (BGHG1 and BGHG2) were purified from the enzyme extract of Aspergillus oryzae HML366 through nondenaturing gel electrophoresis and anion-exchange chromatography. The molecular weights for BGHG1 and BGHG2 were 93 and 138 kDa, respectively. The amino acid sequences were determined by matrix-assisted laser desorption/ionization tandem(More)
Xyr1 (xylanase regulator 1) and ACEI are two transcriptional factors that regulate xylanases and cellulases formation in Trichoderma reesei. To investigate the transcriptional regulation of cellulases, DNA binding domains of both Xyr1 and ACEI in T. reesei were expressed from E. coli. Electrophoresis mobility shift assays showed that both formed complexes(More)
A fibrinolytic enzyme isolated from marine Bacillus subtilis HQS-3 was purified to electrophoretic homogeneity using ammonium sulphate precipitation, alkaline solution treatment, membrane concentration, dialysis, ion exchange, and gel filtration chromatography. SDS-PAGE and gel filtration chromatography showed that it was a monomeric protein with an(More)
In this study, we used native gradient-polyacrylamide gel electrophoresis and electroelution (NGGEE) to purify enzymatic proteins from Trichoderma koningii AS3.2774. With this method, we purified eight enzymatic proteins and classified them to the cellulase system by comparing secretions of T. koningii in inductive medium and in repressive medium. It(More)
In this work, a xylanase-producing strain, Streptomyces griseorubens LH-3, was cultured, and the crude xylanase was prepared. Analysis of its enzymatic properties revealed that the crude xylanase possessed good thermal stability at temperatures below 60 o C, exhibited a wide pH range from 4.0 to 9.0, and was cellulase-free. This crude enzyme was used to(More)
Poly(γ-glutamic acid) (γ-PGA) is a promising biomaterial with a wide range of unique applications. To extensively screen γ-PGA-producing bacteria with high yield and different molecular weight, we developed an integrated high-throughput strategy. Firstly, γ-PGA-producing bacteria were selected in a primary screen plate containing a basic dye (neutral red)(More)
Isomaltooligosaccharides (IMO), the glucosylsaccharides used as food additives, are made from saccharified starch by enzymes or microbial cells with transglycosylation activity. This study aimed to generate shuffled futants of Aspergillus niger with enhanced transglycosylation activity for industrial IMO production. The starting mutant population was(More)
A simple and valid ultraviolet (UV) spectrophotometric method for the determination of poly(γ-glutamic acid) is developed. The method is based on the UV absorption spectrum of γ-PGA in aqueous solution, which exhibits a maximum absorption wavelength at 216 nm. The results obtained were comparable to those obtained with the reported high-performance liquid(More)
After screening with 0.1% esculoside and 0.03% FeCl(3), we identified from rotten wood a fungal isolate HML0366 that produces high amount of β-glucosidase. Phenotypic and rDNA internal transcribed spacer sequence analyses indicated that the isolate belongs to Aspergillus oryzae. The β-glucosidase produced by HML0366 had an activity of 128 U/g. high(More)
A thermophilic strain Bacillus subtilis GXA-28 with capability of γ-PGA production was characterized, and its product was identified. The effect of temperatures on cell growth, γ-PGA yield and molecular weight were investigated. Results showed that γ-PGA yield reached 19.92g/L at 45°C with a high productivity of 0.91g/L/h, and the molecular weight reached(More)