摘要
高山被孢霉(M.alpina)是一株具有较强脂质合成能力的产油微生物,其脂质积累受培养基中碳、氮源调控。探究了不同葡萄糖和酒石酸铵质量浓度对M.alpina生长及脂质积累的影响,并进一步研究不同碳、氮源质量浓度下M.alpina SNF1复合体各亚基的转录水平。结果表明:初始酒石酸铵质量浓度一定时,M.alpina脂肪酸含量随碳氮比(C/N)的增加而提高,C/N为24.6时其脂肪酸含量比C/N为4.6时提高42.6%,初始葡萄糖质量浓度一定时,氮源限制下(C/N=76.7)M.alpina脂肪酸产率达到2.6 g/L,是氮源存在时的1.5~3.2倍,与葡萄糖相比氮源水平对M.alpina脂质积累影响更为显著。氮源一定时高葡萄糖质量浓度(C/N=24.6)下SNF1复合体各亚基转录水平比对照组提高13.9~20.5倍;而氮限制导致的高C/N同样可促进其转录水平的提高。高C/N和氮限制均属于营养失衡信号,说明M.alpina SNF1转录水平的变化是其对胞外营养水平的响应方式,并与脂质积累水平具有相关性。
MortiereUa its lipid synthesis is alpina is an oleaginous filamentous fungus with strong oil producing capacity, and regulated by carbon and nitrogen in culture medium. The effects of different mass concentrations of glucose and ammonium tartrate on biomass and lipid accumulation of M. alpina were studied. Under different mass concentrations of carbon and nitrogen,the transcriptional levels of subunits of M. alpina SNF1 complex were further studied. The results showed that lipid accumulation was basically proportional to carbon to nitrogen ratio（C/N） under the same initial nitrogen mass concentration. When C/N was 24.6, the fatty acid content was 42.6%, higher than that of C/N 4.6. While under the same initial glucose mass concentration, in nitrogen limited culture medium （C/N 76.7 ）, fatty acid yield reached 2.6 g/L, which was 1.5 - 3.2 times of that in nitrogen - rich medium, indicating that nitrogen mass concentration showed a greater impact on lipid production. High glucose mass concentration （C/N 24.6） led to 13.9 -20.5 times higher transcriptional level of SNF1 complex compared with lower glucosegroups under the same nitrogen level, and higher C/N brought by nitrogen limitation also promoted SNF1 transcription. High C/N and nitrogen limi- tation were both unbalanced nutrition signal, and changes in transcriptional level might be the response of M. alpina SNF1 complex to nutrientsignal, which had positive relationship to lipid accumulation.
作者
常璐璐
唐鑫
张灏
陈永泉
陈海琴
陈卫
CHANG Lulu;TANG Xin;ZHANG Hao;CHEN Yongquan;CHEN Haiqin;CHEN Wei(School of Food Science and Technology,Jiangnan University,Wuxi 214122,Jiangsu,China)
出处
《中国油脂》
CAS
CSCD
北大核心
2018年第7期113-118,140,共7页
China Oils and Fats
基金
国家自然科学基金(31722041)
关键词
高山被孢霉
SNF1复合体
脂质积累
营养信号
转录调控
Mortierella alpina
SNF1 complex
lipid accumulation
nutrition signal
transcriptional reg-ulation
