Maintaining caprock integrity is prerequisite for hydrocarbon accumulation. And gypsolyte caprock integrity is mainly affected by fracturing. Composition, damage behavior and mechanical strength of Paleocene Artashi F...Maintaining caprock integrity is prerequisite for hydrocarbon accumulation. And gypsolyte caprock integrity is mainly affected by fracturing. Composition, damage behavior and mechanical strength of Paleocene Artashi Formation gypsolyte rock that seals significant petroleum in the Kashi Sag of Tarim Basin had been revealed via X-ray diffraction and triaxial compression test. The results indicate the Artashi Formation can be lithologically divided into the lower and upper lithologic members. The lower member comprises gypsum as the dominant mineral, and the cohesion and friction coefficient are 8 MPa and 0.315, respectively. Similarly, the upper lithologic member consists mainly of anhydrite at the cohesion and coefficient of internal friction values of 18 MPa and 0.296. Given that the failure criterion and brittle-ductile transition factors during burial, the sealing integrity of Artashi Formation can be quantized for seven different stages. The reservoirs at the bottom of Artashi Formation caprock buried from 2285 m to 3301 m are expected to be the most favorable exploration target in the Kashi Sag.展开更多
We cloned and expressed bile salt hydrolase gene ofLactobacillus plantarum M1-UVS29 in Lactococcus lactis NZ9000 successfully. Gene-specific primers for amplification of L. plantarum bsh were designed by using sequenc...We cloned and expressed bile salt hydrolase gene ofLactobacillus plantarum M1-UVS29 in Lactococcus lactis NZ9000 successfully. Gene-specific primers for amplification of L. plantarum bsh were designed by using sequence which availabled from GenBank. The production of PCR amplicon was confirmed by sequencing and cloned into pMD18-T vector, and then recombined into expression vector pNZ8148 and yielding vector pNZ8148-BSH, pNZ8148-BSH was transferred into Lactococcus lactis NZ9000. Sequencing indicated that the cloned bsh fragment contained 995 nucleotides, and shared 99.3% sequence homology with bsh gene from L. plantarum MBUL10. Cloned bsh fragment was successfully transduced into NICE expression system and confirmed by PCR and restriction digest. Recombinant BSH protein was analyzed by SDS-PAGE. The molecular weight of BSH protein was approximately 37 ku. Activity of the expressed protein was 0.77 μmol· min^-1. The successfully expressed proteins by genetic engineering technology made the function of lactic acid bacteria be abundant and laid the foundation for further researches into cholesterol-lowering lactic acid bacterium food and probiotics.展开更多
Arachidonic acid （AA or ARA）, an essential to-6 polyunsaturated fatty acid （PUFA）, can be produced by Mortierella isabellina. Mutagenesis on Mortierella isabellina As3.3410 was induced to raise ARA production. The...Arachidonic acid （AA or ARA）, an essential to-6 polyunsaturated fatty acid （PUFA）, can be produced by Mortierella isabellina. Mutagenesis on Mortierella isabellina As3.3410 was induced to raise ARA production. The mutant strain of YZ-124 had the highest ARA of 4.72 g. L-1, which was 5.5 times higher than that of the original strain 3.3410. mRNA expression level of △ 6- desaturase was determined in five different kinds of ARA-producing Mortierella isabellina after cultured for 7 days, and in the mutant strain YZ-124 over a 3-8 day time-course. In addition, the desaturase activity and ARA content were measured at the selected time points. The lowest expression of △6-desaturase was observed in the original strain and the highest expression in the mutant strain YZ-124, which increased with increasing time in culture. Furthermore, a positive correlation was observed between the expression levels of △6-desaturase and ARA content. Based on this, △6-desaturase played a significant role in ARA synthesis pathway in Mortierella isabellina.展开更多
基金Project(41672121)supported by the National Natural Science Foundation of ChinaProject(D1438)supported by the China Geological Survey
文摘Maintaining caprock integrity is prerequisite for hydrocarbon accumulation. And gypsolyte caprock integrity is mainly affected by fracturing. Composition, damage behavior and mechanical strength of Paleocene Artashi Formation gypsolyte rock that seals significant petroleum in the Kashi Sag of Tarim Basin had been revealed via X-ray diffraction and triaxial compression test. The results indicate the Artashi Formation can be lithologically divided into the lower and upper lithologic members. The lower member comprises gypsum as the dominant mineral, and the cohesion and friction coefficient are 8 MPa and 0.315, respectively. Similarly, the upper lithologic member consists mainly of anhydrite at the cohesion and coefficient of internal friction values of 18 MPa and 0.296. Given that the failure criterion and brittle-ductile transition factors during burial, the sealing integrity of Artashi Formation can be quantized for seven different stages. The reservoirs at the bottom of Artashi Formation caprock buried from 2285 m to 3301 m are expected to be the most favorable exploration target in the Kashi Sag.
基金Supported by the National Natural Science Fund Project(31171657)Heilongjiang Province Natural Fund Project(ZD201207)Heilongjiang Province Postdoctoral Special Funds(LBH-Q13133)
文摘We cloned and expressed bile salt hydrolase gene ofLactobacillus plantarum M1-UVS29 in Lactococcus lactis NZ9000 successfully. Gene-specific primers for amplification of L. plantarum bsh were designed by using sequence which availabled from GenBank. The production of PCR amplicon was confirmed by sequencing and cloned into pMD18-T vector, and then recombined into expression vector pNZ8148 and yielding vector pNZ8148-BSH, pNZ8148-BSH was transferred into Lactococcus lactis NZ9000. Sequencing indicated that the cloned bsh fragment contained 995 nucleotides, and shared 99.3% sequence homology with bsh gene from L. plantarum MBUL10. Cloned bsh fragment was successfully transduced into NICE expression system and confirmed by PCR and restriction digest. Recombinant BSH protein was analyzed by SDS-PAGE. The molecular weight of BSH protein was approximately 37 ku. Activity of the expressed protein was 0.77 μmol· min^-1. The successfully expressed proteins by genetic engineering technology made the function of lactic acid bacteria be abundant and laid the foundation for further researches into cholesterol-lowering lactic acid bacterium food and probiotics.
基金Supported by the National Natural Science Foundation of China(31171657)Heilongjiang Youth Science Foundation(QC2010093)+1 种基金Heilongjiang Natural Science Foundation(20100481037)Key Projects on Ministry of Education in Heilongjiang(12511Z022)
文摘Arachidonic acid （AA or ARA）, an essential to-6 polyunsaturated fatty acid （PUFA）, can be produced by Mortierella isabellina. Mutagenesis on Mortierella isabellina As3.3410 was induced to raise ARA production. The mutant strain of YZ-124 had the highest ARA of 4.72 g. L-1, which was 5.5 times higher than that of the original strain 3.3410. mRNA expression level of △ 6- desaturase was determined in five different kinds of ARA-producing Mortierella isabellina after cultured for 7 days, and in the mutant strain YZ-124 over a 3-8 day time-course. In addition, the desaturase activity and ARA content were measured at the selected time points. The lowest expression of △6-desaturase was observed in the original strain and the highest expression in the mutant strain YZ-124, which increased with increasing time in culture. Furthermore, a positive correlation was observed between the expression levels of △6-desaturase and ARA content. Based on this, △6-desaturase played a significant role in ARA synthesis pathway in Mortierella isabellina.
