王璐, 张瑶, 杨俊换, 王艳霞, 宋元达. 卷枝毛霉重组菌株Mc-MT-2培养条件优化及产油特性[J]. 农业工程学报, 2021, 37(8): 251-258. DOI: 10.11975/j.issn.1002-6819.2021.08.029
    引用本文: 王璐, 张瑶, 杨俊换, 王艳霞, 宋元达. 卷枝毛霉重组菌株Mc-MT-2培养条件优化及产油特性[J]. 农业工程学报, 2021, 37(8): 251-258. DOI: 10.11975/j.issn.1002-6819.2021.08.029
    Wang Lu, Zhang Yao, Yang Junhuan, Wang Yanxia, Song Yuanda. Optimization of the culture conditions and lipid production characteristics of Mucor circinelloides recombinant strain Mc-MT-2[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2021, 37(8): 251-258. DOI: 10.11975/j.issn.1002-6819.2021.08.029
    Citation: Wang Lu, Zhang Yao, Yang Junhuan, Wang Yanxia, Song Yuanda. Optimization of the culture conditions and lipid production characteristics of Mucor circinelloides recombinant strain Mc-MT-2[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2021, 37(8): 251-258. DOI: 10.11975/j.issn.1002-6819.2021.08.029

    卷枝毛霉重组菌株Mc-MT-2培养条件优化及产油特性

    Optimization of the culture conditions and lipid production characteristics of Mucor circinelloides recombinant strain Mc-MT-2

    • 摘要: 前期工作构建了苹果酸转运蛋白基因过表达的卷枝毛霉重组菌株Mc-MT-2,该菌株的脂质含量大幅度提高。该研究从培养基成分筛选、微生物生长控制以及发酵模式等方面深入探讨Mc-MT-2菌株发酵产油脂的调控策略。结果表明,Mc-MT-2菌株最佳生长及产孢培养条件是以葡萄糖与苹果酸为复合碳源且复合配比为9∶1,氮源为胰蛋白胨,其他成分同Kendrick培养基,初始pH值为5。经分批培养获得生物量、脂质含量和脂质产量分别为11.2 g/L,24%和2.6 g/L。在3 L发酵罐扩大培养中,补料培养Mc-MT-2菌株获得生物量、脂质含量和脂质产量最大值为15.4 g/L、28.6%和4.4 g/L,比分批培养分别提高1.38、1.19和1.69倍。该研究为卷枝毛霉重组菌株Mc-MT-2在脂质生产中的进一步应用奠定理论基础。

       

      Abstract: Abstract: Mucor circinelloides recombinant strain Mc-MT-2 is generally responsible for the trans-membrane transport of malate and citric acid in lipid synthesis. A preliminary research has been carried out to successfully construct the M. circinelloides recombinant strain Mc-MT-2 overexpressing the malate transporter gene. It was found that the strain can be expected to behave potential applications in lipid production, indicating that the lipid content of the strain was 70% higher than that of the control strain. In addition, the lipid accumulation level of microorganisms depends mainly on the strain characteristics, growth environment, and fermentation. In this study, a regulation strategy of the Mc-MT-2 strain was presented to produce the lipid, ranging from the selection of medium composition to microbial growth control and fermentation mode. An investigation was made to clarify the effects of nitrogen/carbon sources and pH values on the growth and sporulation of recombinant strain Mc-MT-2. An optimal condition was achieved for the growth and sporulation culture of the Mc-MT-2 strain, where the compound carbon source of glucose and malate with the compound ratio of 9:1, tryptone as the nitrogen source, other components as same as Kendirck medium, and pH 5. The yield of spores significantly increased under optimized conditions, about 4 times the initial one. A systematic optimization was also performed on the plate culture conditions, such as nitrogen/carbon source, and pH value. A batch cultivation was further carried out in a 1.5 L fermenter to determine the optimal fermentation of recombinant strain Mc-MT-2 in lipid production. The fermentation conditions were set as follows: a temperature of 30°C, pH value of 5.0, aeration of 0.5 L/(L·min), a rotation speed of 500 rpm, and a fermentation time of 96 h. The biomass, lipid content, and yield after batch cultivation reached 11.2 g/L, 24%, and 2.6 g/L, respectively. A fed-batch fermentation culture of the Mc-MT-2 strain was carried out in a 3 L fermenter to further increase the lipid production. The fermentation conditions were set as follows: a temperature of 30°C, pH of 5.0, aeration of 0.5 L/(L·min), a rotation speed of 500 rpm, and a fermentation time of 120 h. The feed solution was added every 24 hours, and the glucose concentration was maintained at about 10-15 g/L, after the glucose was exhausted (the dissolved oxygen rose sharply). The maximum biomass, lipid content, and yield of the Mc-MT-2 strain in the fed-batch culture were 15.4 g/L, 28.6%, and 4.4 g/L, which were improved by 1.38-, 1.19-, and 1.69-fold, respectively, compared with the batch culture. There was an obvious difference in the composition of fatty acid for the Mc-MT-2 strain during fermentation, with a high content of oleic acid (C18: 1), while low contents of linoleic acid and linolenic acid (C18: 2, C18: 3), as well as no or less tetradecanoic acid (C14:0), and palmitic acid (C16:1). This finding can offer a potential theoretical foundation for the M. circinelloides recombinant strain Mc-MT-2 to be further applied in the lipid production suitable for industrial requirements.

       

    /

    返回文章
    返回