title: Lovastatin in Aspergillus terreus: fermented rice straw extracts interferes with methane production and gene expression in Methanobrevibacter smithii.
abstract: Lovastatin, a natural byproduct of some fungi, is able to inhibit HMG-CoA (3-hydroxy-3 methyl glutaryl CoA) reductase. This is a key enzyme involved in isoprenoid synthesis and essential for cell membrane formation in methanogenic Archaea. In this paper, experiments were designed to test the hypothesis that lovastatin secreted by Aspergillus terreus in fermented rice straw extracts (FRSE) can inhibit growth and CH4 production in Methanobrevibacter smithii (a test methanogen). By HPLC analysis, 75% of the total lovastatin in FRSE was in the active hydroxyacid form, and in vitro studies confirmed that this had a stronger effect in reducing both growth and CH4 production in M. smithii compared to commercial lovastatin. Transmission electron micrographs revealed distorted morphological divisions of lovastatin- and FRSE-treated M. smithii cells, supporting its role in blocking normal cell membrane synthesis. Real-time PCR confirmed that both commercial lovastatin and FRSE increased (P < 0.01) the expression of HMG-CoA reductase gene (hmg). In addition, expressions of other gene transcripts in M. smithii. with a key involvement in methanogenesis were also affected. Experimental confirmation that CH4 production is inhibited by lovastatin in A. terreus-fermented rice straw paves the way for its evaluation as a feed additive for mitigating CH4 production in ruminants.
authors.affiliation: Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), 43400 Selangor, Serdang, Malaysia.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Faseleh Jahromi
authors.forename: Juan Boo
authors.initials: JB
authors.lastname: Liang
authors.forename: Yin Wan
authors.initials: YW
authors.lastname: Ho
authors.forename: Rosfarizan
authors.initials: R
authors.lastname: Mohamad
authors.forename: Yong Meng
authors.initials: YM
authors.lastname: Goh
authors.forename: Parisa
authors.initials: P
authors.lastname: Shokryazdan
authors.forename: James
authors.initials: J
authors.lastname: Chin
mesh_terms: D000214:Acyl Coenzyme A; D001230:Aspergillus / Q000737:chemistry* / Q000254:growth & development; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent / Q000235:genetics / Q000378:metabolism*; D008148:Lovastatin / Q000494:pharmacology; D008697:Methane / Q000096:biosynthesis* / Q000737:chemistry; D017014:Methanobacterium / Q000187:drug effects*; D012275:Oryza / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000214:Acyl Coenzyme A; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010936:Plant Extracts; C008047:3-hydroxy-3-methylglutaryl-coenzyme A; D008148:Lovastatin; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D008697:Methane