Shen Xianrong

Isolation and identification of biodegradation ability of alkane-degrading bacteria: Molecular detection and analysis of alkane hydroxylase genes

This study was conducted to characterize and to detect the alkane degradation capacity of the bacterial strain (strain Y9) isolated from the sea mud of the crude oil-polluted Dinghai area in China. A Gramnegative, strictly aerobic, oxidase negative, and catalase positive bacterium, strain Y9 was isolated and identified as Acinetobacter sp. based on its physiological characteristics and its 16S rRNA gene sequence analysis. The 16S rDNA of strain Y9 sequence is 99.8% identical with Acinetobacter venetianus RAG-1T. The Y9 strain had an obligate requirement for NaCl but could not tolerate high salt concentrations. Strain Y9 was able to degrade C9~C22 n-alkanes from diesel oil as the sole carbon source, and the degradation rate was up to 53.28% in 7 days at 30°C, pH 8.0. The concentrations of the initial diesel oil and initial bacteria were 4 and 2% (v/v), respectively. The length of alkane hydroxylase gene (alkB) and CYP153A obtained by PCR are 544 and 864 bp, and displays 84 and 98% with Acinetobacter sp. M-1 and Acinetobacter sp. OC4, respectively.

Expression, purification of a synthetic fuse-protein-TSF from PF4 and TSP1 fragments and its effect on angiogenesis and tumor growth

Sequences encoding PF4 (58–70) and TSP1 (429–459) were linked to yield a single gene TSF which encodes the fuse-protein of TSF. The gene was cloned into a pGEX-2T expression vector to generate a protein GST-TSF, which was strongly expressed inE. coli. The purified GST-TSF was degraded with thrombin to generate the protein TSF. With the methods of MTT and wound repair assay, the effects of TSF on the proliferation and migration of EC were detected, respectively. The results showed that TSF significantly suppressed BAEC proliferation and migration in a dose-dependent manner. The fuse protein GST-TSF, and the peptides PF4 (58–70) and TSP1 (429–459) also inhibited BAEC proliferation and migration, respectively, but their inhibition rates were not as high as TSF. Using the CAM assay, it was shown that TSF, GST-TSF, PF4 (58–70) and TSP1 (429–459) inhibited angiogenesis in chick CAM potentially, the effect of TSF was the highest.In vivo, the growth of Lewis lung carcinoma was potently inhibited by TSF treatment, and the inhibition rate was 68.75% at a dose of 1.00 μmol/kg · d. These findings suggest that the design on TSF gene was successful, and TSF with its anti-angiogenic and anti-tumor activity, should be a useful source of the inhibitor.