Liu Qianrui, Zheng Yunfan, Liu Baixue, Tang Fufang, Shao Yanchun
College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China.
J Basic Microbiol. 2023 Oct;63(10):1128-1138. doi: 10.1002/jobm.202300138. Epub 2023 May 26.
Monascus spp. can produce a variety of beneficial metabolites widely used in food and pharmaceutical industries. However, some Monascus species contain the complete gene cluster responsible for citrinin biosynthesis, which raises our concerns about the safety of their fermented products. In this study, the gene Mrhos3, encoding histone deacetylase (HDAC), was deleted to evaluate its effects on the production of mycotoxin (citrinin) and the edible pigments as well as the developmental process of Monascus ruber M7. The results showed that absence of Mrhos3 caused an enhancement of citrinin content by 105.1%, 82.4%, 111.9%, and 95.7% at the 5th, 7th, 9th, and 11th day, respectively. Furthermore, deletion of Mrhos3 increased the relative expression of citrinin biosynthetic pathway genes including pksCT, mrl1, mrl2, mrl4, mrl6, and mrl7. In addition, deletion of Mrhos3 led to an increase in total pigment content and six classic pigment components. Western blot results revealed that deletion of Mrhos3 could significantly elevate the acetylation level of H3K9, H4K12, H3K18, and total protein. This study provides an important insight into the effects of hos3 gene on the secondary metabolites production in filamentous fungi.
红曲霉菌株能够产生多种有益代谢产物，广泛应用于食品和制药行业。然而，一些红曲霉菌种含有负责桔霉素生物合成的完整基因簇，这引发了我们对其发酵产品安全性的担忧。在本研究中，编码组蛋白脱乙酰酶（HDAC）的基因Mrhos3被删除，以评估其对霉菌毒素（桔霉素）和食用色素产量以及红曲霉菌M7发育过程的影响。结果表明，缺失Mrhos3分别在第5天、第7天、第9天和第11天导致桔霉素含量提高了105.1%、82.4%、111.9%和95.7%。此外，Mrhos3的缺失增加了桔霉素生物合成途径基因（包括pksCT、mrl1、mrl2、mrl4、mrl6和mrl7）的相对表达。另外，Mrhos3的缺失导致总色素含量和六种经典色素成分增加。蛋白质免疫印迹结果显示，Mrhos3的缺失可显著提高H3K9、H4K12、H3K18和总蛋白的乙酰化水平。本研究为hos3基因对丝状真菌次级代谢产物产生的影响提供了重要见解。
