大曲丝状真菌的物种多样性及其次级代谢产物的合成潜力

Diversity of Daqu filamentous fungi and their potentials for synthesizing bioactive compounds

通过高通量测序研究了大曲中丝状真菌的物种多样性,并结合荧光定量PCR对丝状真菌进行了定量分析;此外,还通过纯培养对高温曲中的丝状真菌进行筛选,并使用简并引物对分离株的次级代谢产物合成酶基因进行扩增。结果表明,Thermomyces属的丰度随大曲温度的升高而上升,而Aspergillus属的丰度随大曲温度的升高而下降;丝状真菌在大曲中的生物量同样随大曲温度的升高而下降;利用纯培养的方法从高温大曲中分离得到50株丝状真菌,隶属于10个属(Aspergillus、Monascus、Byssochlamys、Lichtheimia、Rhizomucor、Mucor、Arthrinium、Alternaria、Thermomyces和Rasamsonia),并且这些丝状真菌含有多种次级代谢产物合成酶表达基因;大曲来源的丝状真菌具有强大的次级代谢产物合成潜力,大曲是优良的微生物和次级代谢产物生物合成的基因库,可能成为挖掘新天然产物的新来源。

This study investigated the diversity of Daqu filamentous fungi and their abilities to synthesize bioactive compounds. High- throughput sequencing was used to study the diversity of filamentous fungi followed by quantitative analysis using fluorescence real-time PCR. Further, culture-depended method was applied to isolate the fungi followed by amplifying the genes involved in secondary metabolites biosynthesis. It was found that the abundance of genus Thermomyces increased with increasing temperature of Daqu , while the abundance of genus Aspergillus decreased. Besides, the biomass of filamentous fungi decreased with temperature. There were 50 filamentous fungal isolates affiliated to10 genera ( Aspergillus, Monascus, Byssochlamys, Lichtheimia, Rhizomucor, Mucor, Arthrinium, Alternaria, Thermomyces , and Rasamsonia ) obtained from high temperature Daqu , and these strains had many genes involved in producing secondary metabolites, indicating that Daqu -derived filamentous fungi had great potentials to produce multiple types of secondary metabolites. Therefore, Daqu is a superior reservoir of microorganisms and genes for secondary metabolites biosynthesis, which can be a new source for mining new natural products.