Mortierella isabellina was found to accumulate large amounts of unsaturated fatty acids when it was grown in a medium containing butanol(5 g/L) and yeast extract(10 g/L) and cultivated at 25 ℃ for 5 d during which ad...Mortierella isabellina was found to accumulate large amounts of unsaturated fatty acids when it was grown in a medium containing butanol(5 g/L) and yeast extract(10 g/L) and cultivated at 25 ℃ for 5 d during which additional feeding butanol of 2 g/L was fed after being cultivated for 48 h . The resultant mycelial lipids accounted for 40 1% of the dry mycelia, while about 34% of butanol in the medium was converted. The mycelial lipids contained four kinds of unsaturated fatty acids, i.e ., palmitoleic(4 9%), oleic(54 1%), linoleic(10 4%) and linolenic(5 4%) acids. Those accounted for 74 8% of the total fatty acids. The effects of the culture conditions, such as cultivation temperature, initial pH of the medium and additional feeding butanol in the course of cultivation, on the production of mycelial lipids by M. isabellina were studied.展开更多
A developed method was used for the enhancement of arachidonic acid production by M. isabellina. An orthogonal, rotatable and central composite design was applied to determine the optimum conditions for protoplast reg...A developed method was used for the enhancement of arachidonic acid production by M. isabellina. An orthogonal, rotatable and central composite design was applied to determine the optimum conditions for protoplast regeneration mutagenesis. The results showed that a commixture enzyme （cellulase and glusulase） at the concentration of 4%, enzymolysis temperature at 30℃ and enzymolysis time on 7.5 h were the optimal conditions, in which the lethality of M. isabellina spores was 78.4%. After mutagenesis and re-screenings, M. isabellina mutant Y-69 was obtained. GC analysis showed that the yield of arachidonic acid by Y-69 （2.92 g. L-1） was 3.56 times higher than that of the wild-type strain （0.82 g.L-1）. Pass generation tests showed that the properties of Y-69 by mutation were readily inherited.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
The regio- and stereo-selective hydroxylations of two ingenane diterpenoids, 20-deoxyingenol(1) and 13-oxyingenol dodecanoat(2), by the filamentous fungi Mortierella ramanniana and Gibberella fujikuroi were investigat...The regio- and stereo-selective hydroxylations of two ingenane diterpenoids, 20-deoxyingenol(1) and 13-oxyingenol dodecanoat(2), by the filamentous fungi Mortierella ramanniana and Gibberella fujikuroi were investigated in the present study. Four undescribed metabolites(3–6) of substrate 1 and two undescribed metabolites(7 and 8) of substrate 2 were isolated. All the lites were identified as hydroxylated ingenane derivatives by extensive NMR and HR-ESI-MS data analyses. All the biotransformed compounds and the substrates were evaluated for their cytotoxicities against three human cancer cell lines, including human colon cancer Caco-2, breast cancer MCF-7, and adriamycin(ADM)-resistant MCF-7/ADM cell lines. All ingenane alcohols(1, and 3–6) displayed no significant cytotoxic activities. The substrate 13-oxyingenol dodecanoat(2) showed moderate cytotoxicity with IC50 values being 35.59 ± 5.37 μmol·L^(-1)(Caco-2), 24.04 ± 4.70 μmol·L^(-1)(MCF-7), and 22.24 ± 5.19 μmol·L^(-1)(MCF-7/ADM). However, metabolites 7 and 8 displayed no significant cytotoxicity. These results indicated that the hydroxylation at the C^(-1)3 aliphatic acid ester of substrate 2 can significantly reduce the cytotoxic activity.展开更多
Mortierella isabellina was found to accumulate lipid with 2% hexadecanol and 1% yeast extract as the growth substrates. The amount of lipid reached 64.5% of dry mycelia, and unsaturated acids accounted for 97.05% of t...Mortierella isabellina was found to accumulate lipid with 2% hexadecanol and 1% yeast extract as the growth substrates. The amount of lipid reached 64.5% of dry mycelia, and unsaturated acids accounted for 97.05% of the total fatty acids. Mean while, 75% of hexadecanol in medium was converted to lipid. The biosynthetic route from hexadecanol to linoleic acid was presumed as follows: HexadecanolC18∶0（Steric acid）C18∶1（Oleic acid）C18∶2（Linoleic展开更多
基金Supported by the National Natural Science Foundation of China(No.2 98730 18)
文摘Mortierella isabellina was found to accumulate large amounts of unsaturated fatty acids when it was grown in a medium containing butanol(5 g/L) and yeast extract(10 g/L) and cultivated at 25 ℃ for 5 d during which additional feeding butanol of 2 g/L was fed after being cultivated for 48 h . The resultant mycelial lipids accounted for 40 1% of the dry mycelia, while about 34% of butanol in the medium was converted. The mycelial lipids contained four kinds of unsaturated fatty acids, i.e ., palmitoleic(4 9%), oleic(54 1%), linoleic(10 4%) and linolenic(5 4%) acids. Those accounted for 74 8% of the total fatty acids. The effects of the culture conditions, such as cultivation temperature, initial pH of the medium and additional feeding butanol in the course of cultivation, on the production of mycelial lipids by M. isabellina were studied.
基金Supported by Young Scientifi c Fund of Heilongjiang Province (QC2010093)Project of Daqing Scientifi c Program (sggh2009-029)
文摘A developed method was used for the enhancement of arachidonic acid production by M. isabellina. An orthogonal, rotatable and central composite design was applied to determine the optimum conditions for protoplast regeneration mutagenesis. The results showed that a commixture enzyme （cellulase and glusulase） at the concentration of 4%, enzymolysis temperature at 30℃ and enzymolysis time on 7.5 h were the optimal conditions, in which the lethality of M. isabellina spores was 78.4%. After mutagenesis and re-screenings, M. isabellina mutant Y-69 was obtained. GC analysis showed that the yield of arachidonic acid by Y-69 （2.92 g. L-1） was 3.56 times higher than that of the wild-type strain （0.82 g.L-1）. Pass generation tests showed that the properties of Y-69 by mutation were readily inherited.
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.
文摘The regio- and stereo-selective hydroxylations of two ingenane diterpenoids, 20-deoxyingenol(1) and 13-oxyingenol dodecanoat(2), by the filamentous fungi Mortierella ramanniana and Gibberella fujikuroi were investigated in the present study. Four undescribed metabolites(3–6) of substrate 1 and two undescribed metabolites(7 and 8) of substrate 2 were isolated. All the lites were identified as hydroxylated ingenane derivatives by extensive NMR and HR-ESI-MS data analyses. All the biotransformed compounds and the substrates were evaluated for their cytotoxicities against three human cancer cell lines, including human colon cancer Caco-2, breast cancer MCF-7, and adriamycin(ADM)-resistant MCF-7/ADM cell lines. All ingenane alcohols(1, and 3–6) displayed no significant cytotoxic activities. The substrate 13-oxyingenol dodecanoat(2) showed moderate cytotoxicity with IC50 values being 35.59 ± 5.37 μmol·L^(-1)(Caco-2), 24.04 ± 4.70 μmol·L^(-1)(MCF-7), and 22.24 ± 5.19 μmol·L^(-1)(MCF-7/ADM). However, metabolites 7 and 8 displayed no significant cytotoxicity. These results indicated that the hydroxylation at the C^(-1)3 aliphatic acid ester of substrate 2 can significantly reduce the cytotoxic activity.
文摘Mortierella isabellina was found to accumulate lipid with 2% hexadecanol and 1% yeast extract as the growth substrates. The amount of lipid reached 64.5% of dry mycelia, and unsaturated acids accounted for 97.05% of the total fatty acids. Mean while, 75% of hexadecanol in medium was converted to lipid. The biosynthetic route from hexadecanol to linoleic acid was presumed as follows: HexadecanolC18∶0（Steric acid）C18∶1（Oleic acid）C18∶2（Linoleic
