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He Y.-C.,Changzhou University | He Y.-C.,East China University of Science and Technology | Liu Y.-Y.,Guangxi University | Ma C.-L.,Changzhou University | And 2 more authors.
Biotechnology and Bioprocess Engineering | Year: 2011

We successfully modified a ferric hydroxamate spectrophotometry method for assaying glycolic acid. Comparable to the high-performance liquid chromatography (HPLC)-based method, ferric hydroxamate spectrophotometry can be used to accurately monitor the time course of glycolonitrile bioconversion. Glycolic acid was assayed simply and rapidly at room temperature (25 ∼ 35°C). Optimum culture conditions were obtained using this method to assay the glycolonitrile-hydrolyzing activity of Rhodococcus sp. CCZU10-1. The preferred carbon and nitrogen sources and ideal inducer were glucose (10 g/L), a composite of peptone (10 g/L) plus yeast extract (5 g/L), and e-caprolactam (2 mmol/L), respectively. The optimal growth temperature and initial medium pH for Rhodococcus sp. CCZU10-1 glycolonitrile-hydrolyzing activity were 30oC and pH 7.0. Modified ferric hydroxamate spectrophotometry could potentially be employed to assay other carboxylic acids. © The Korean Society for Biotechnology and Bioengineering and Springer 2011. Source

He Y.-C.,Changzhou University | He Y.-C.,East China University of Science and Technology | He Y.-C.,Hubei University of Education | Ma C.-L.,Changzhou University | And 4 more authors.
Applied Microbiology and Biotechnology | Year: 2011

Nitrile-hydrolyzing enzymes (nitrilase or nitrile hydratase/amidase) have been widely used in the pharmaceutical industry for the production of carboxylic acids and their derivatives, and it is important to build a method for screening for nitrile-hydrolyzing enzymes. In this paper, a simple, rapid, and high-throughput screening method based on the ferric hydroxamate spectrophotometry has been proposed. To validate the accuracy of this screening strategy, the nitrilases from Rhodococcus erythropolis CGMCC 1.2362 and Alcaligenes sp. ECU0401 were used for evaluating the method. As a result, the accuracy for assaying aliphatic and aromatic carboxylic acids was as high as the HPLC-based method. Therefore, the method may be potentially used in the selection of microorganisms or engineered proteins with nitrile-hydrolyzing enzymes. © 2010 Springer-Verlag. Source

He Y.-C.,Changzhou University | He Y.-C.,East China University of Science and Technology | Liu F.,Changzhou University | Zhang D.-P.,Changzhou University | And 4 more authors.
Applied Biochemistry and Biotechnology | Year: 2015

In this study, it was the first report that Bacillus sp. CCZU11-1 was used for the biotransformation of 1,3-propanediol cyclic sulfate (1,3-PDS) and its derivatives. The catalytic performance of Bacillus sp. sulfatase in the biotransformation of 1,3-PDS was significantly improved by biocatalyst permeabilization and immobilization. Using cell permeabilization, the hydrolytic activity of the whole-cell biocatalyst was increased by 3.5-fold after 1.5 h of pretreatment with 10 % (v/v) toluene at 30 °C and pH 7.0. Biotransformation of 20 mM 1,3-PDS for 24 h, 1,3-propanediol (1,3-PD) could be obtained in the yield of 97.4 % under the optimized reaction condition. Additionally, the immobilized biocatalysts, permeabilized cells entrapped in calcium alginate, and cross-linked enzyme aggregates were further employed to biotansform 1,3-PDS. Moreover, the total operational time of the immobilized biocatalysts could reach above 240 h with high conversion rate (>90 %). © 2015, Springer Science+Business Media New York. Source

He Y.-C.,Changzhou University | Tao Z.-C.,Changzhou University | Zhang D.-P.,Changzhou University | Yang Z.-X.,Changzhou University | And 2 more authors.
Biotechnology Letters | Year: 2015

Rhodococcus sp. CGMCC 4911 transformed 1,3-propanediol cyclic sulfate (1,3-PDS) and its derivatives into corresponding diols. Ethylene sulfate, glycol sulfide, 1,3-PDS, and 1,2-propanediol cyclic sulfate were effectively hydrolyzed with growing cells. (R)-1,2-Propanediol (>99 % e.e.) was obtained at 44 % yield with growing cells. Glycol sulfide, ethylene sulfate, and 1,3-PDS were converted into the corresponding diols at 94.6, 96.3, and 98.3 %, respectively. Optimal reaction conditions with lyophilized resting cells were 30 °C, pH 7.5, and cell dosage 17.9 mg cell dry wt/ml. 1,3-Propanediol was obtained from 50 mM 1,3-PDS at 97.2 % yield by lyophilized cells after 16 h. Lyophilized cells were entrapped in calcium alginate with a half-life of 263 h at 30 °C, and the total operational time of the immobilized biocatalysts could reach over 192 h with a high conversion rate. © 2014, Springer Science+Business Media Dordrecht. Source

He Y.C.,Changzhou University | Ma C.L.,Changzhou University | Ma C.L.,Changzhou Kangpu Pharmaceutical Co. | Xia D.Q.,Changzhou University | And 3 more authors.
Chemical Papers | Year: 2011

Ionic liquid (IL) 1-ethyl-3-methylimidazolium dimethylphosphate ([Emim]DMP) was chosen as an environment-friendly solvent to enzymatically hydrolyze cellulose in situ. Under optimal reaction condition, 80.2 % of cellulose (10 mg mL-1) were converted to glucose in aqueous-IL-DMSO (ℓr = 74 : 25 : 1) media at 55.C in 18 h. Finally, fermentability of the recovered hydrolyzates was evaluated using Saccharomyces cerevisiae which is able to ferment hydrolyzates efficiently, the ethanol production was 0.44 g g -1 of glucose within 24 h of the process. Such information is vital for the saccharification of more complex cellulose materials and for the fermentation of hydrolyzates into biofuel. © 2011 Institute of Chemistry, Slovak Academy of Sciences. Source

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