Effect of low expression level of acetyl coenzyme A synthetase gene on secondary metabolite in Monascus
Acetyl-coenzyme A (CoA) is a key metabolite produced by the acetyl-CoA synthetase (ACS) gene in energy metabolism and biosynthetic pathways. ACS is speculated to be the branching site of monacolin K (MK) and citrinin production and related to the metabolite production of Monascus. In this study, the ACS expression was inhibited by ribonucleic acid interference (RNAi). T7 was selected for a follow-up analysis of the lowest ACS expression, which was 0.401 times higher than that of the wild-type strain. The effects on the colony morphology of Monascus were determined. The morphological characteristics of mycelia and spores were observed under a scanning electron microscope. The contents of secondary metabolites, namely, MK and citrinin, were determined through high performance liquid chromatography (HPLC). Colour values were measured with a spectrophotometer. Results showed that the low ACS expression could inhibit the growth of Monascus colonies and the hypha and affect the formation and morphology of Monascus M1 spores. It could also inhibit the production of the main secondary metabolites, namely, MK, citrinin, and pigment.
Endo A. (1979): Monacolin K, a new hypocholesterolemic agent produced by a Monascus species. Journal of Antibiotics, 32: 852–854.
https://doi.org/10.7164/antibiotics.32.852
Gu Q., Yuan Q., Zhao D., Huang J., Hsiang T., Wei Y., Zheng L. (2019): Acetyl-coenzyme A synthetase gene Chacs1 is essential for lipid metabolism, carbon utilization and virulence of the hemibiotrophic fungus Colletotrichum higginsianum. Molecular Plant Pathology, 20: 107–123.
https://doi.org/10.1111/mpp.12743
Hajjaj H., Blanc P.J., Groussac E., Goma G., Loubiere P. (2015): Improvement of red pigment/citrinin production ratio as a function of environmental conditions by Monascus ruber. Biotechnology and Bioengineering, 64: 497–501.
https://doi.org/10.1002/(SICI)1097-0290(19990820)64:4<497::AID-BIT12>3.0.CO;2-Q
Hajjaj H.A., Klaébé Loret M.O., Goma G., Blanc P.J., Francois J. (1999): Biosynthetic pathway of citrinin in the filamentous fungus Monascus ruber as revealed by 13c nuclear magnetic resonance. Applied and Environmental Microbiology, 65: 311–314.
https://doi.org/10.1128/AEM.65.1.311-314.1999
Hynes M.J., Murray S.L. (2010): ATP-citrate lyase is required for the production of cytosolic acetyl-CoA and development in Aspergillus nidulans. Eukaryotic Cell, 9: 1039–1048.
https://doi.org/10.1128/EC.00080-10
Ji Y.K., Kim H.J., Oh J.H., Lee I. (2010): Characteristics of Monascus sp. isolated from Monascus fermentation products. Food Science and Biotechnology, 19: 1151–1157.
https://doi.org/10.1007/s10068-010-0164-1
Liang G., Hong Z., Li T., Ming G.F., Duan X.W., Wang J.S., Jiang Y.M. (2019): Molecular signatures of cytotoxic effects in human embryonic kidney 293 cells treated with single and mixture of ochratoxin A and citrinin. Food and Chemical Toxicology, 123: 374–384.
https://doi.org/10.1016/j.fct.2018.11.015
Lin L., Wu S., Li Z., Ren Z., Wang C. (2018): High expression level of mok E enhances the production of monacolin K in Monascus. Food Biotechnology, 32: 35–46.
https://doi.org/10.1080/08905436.2017.1413985
Liu H.Q., Huang Z.F., Yang S.Z., Tian X.F., Wu Z.Q. (2021): Inducing red pigment and inhibiting citrinin production by adding lanthanum(III) ion in Monascus purpureus fermentation. Applied Microbiology and Biotechnology, 105: 1905–1912.
https://doi.org/10.1007/s00253-021-11162-9
Manzoni M., Rollini M. (2002): Biosynthesis and biotechnological production of statins by filamentous fungi and application of these cholesterol-lowering drugs. Applied Microbiology and Biotechnology, 58: 555–564.
https://doi.org/10.1007/s00253-002-0932-9
Mulder K.C., Mulinari F., Franco O.L., Soares M.S., Magalhães B.S., Parachin N.S. (2015): Lovastatin production: From molecular basis to industrial process optimization. Biotechnology Advances, 33: 648–665.
https://doi.org/10.1016/j.biotechadv.2015.04.001
Sengupta S., Bhattacharya S., Karmakar A., Ghosh S., Datta S.K. (2021): RNAi-mediated down-regulation of itpk-2 enhanced inorganic phosphorus and minerals in the transgenic rice. Journal of Biosciences, 46: 32–45.
https://doi.org/10.1007/s12038-021-00154-6
Seraman S., Rajendran A., Thangavelu V. (2010): Statistical optimization of anticholesterolemic drug lovastatin production by the red mold Monascus purpureus. Food and Bioproducts Processing, 88: 266–276.
https://doi.org/10.1016/j.fbp.2010.01.006
Son H., Lee J., Park A.R., Lee Y.W. (2011): ATP citrate lyase is required for normal sexual and asexual development in Gibberella zeae. Fungal Genetics and Biology, 48: 408–417.
https://doi.org/10.1016/j.fgb.2011.01.002
Srianta I., Zubaidah E., Estiasih T., Iuchi Y., Harijono, Yamada M. (2017): Antioxidant activity of pigments derived from Monascus purpureus-fermented rice, corn, and sorghum. International Food Research Journal, 24: 1186–1191.
Srianta I., Ristiarini S., Nugerahani I. (2020): Pigments extraction from Monascus-fermented durian seed. IOP Conference Series Earth and Environmental Science, 443: 1–7.
https://doi.org/10.1088/1755-1315/443/1/012008
Su N.W., Lin Y.L., Lee M.H., Ho C.Y. (2005): Ankaflavin from Monascus fermented red rice exhibits selective cytotoxic effect and induces cell death on Hep G2 cells. Journal of Agricultural and Food Chemistry, 53: 1949–1954.
https://doi.org/10.1021/jf048310e
Wang L., Wang W., Xu G. (2011): Promotion of monacolin K production by Agrobacterium tumefaciens-mediated transformation in Monascus albidus 9901. Current Microbiology, 62: 501–507.
https://doi.org/10.1007/s00284-010-9735-x
Yang C.W., Mousa S.A. (2012): The effect of red yeast rice (Monascus purpureus) in dyslipidemia and other disorders. Complement Therapies in Medicine, 20: 466–474.
https://doi.org/10.1016/j.ctim.2012.07.004
Zhen Z., Xiong X., Liu Y., Zhang J., Wang S., Li L., Gao M. (2019): NaCl inhibits citrinin and stimulates Monascus pigments and monacolin K production. Toxins, 11: 118–128.
https://doi.org/10.3390/toxins11020118
