title: Monitoring of gene expression in Fibrobacter succinogenes S85 under the co-culture with non-fibrolytic ruminal bacteria.
abstract: Fibrobacter succinogenes is one of the most pivotal fibrolytic bacterial species in the rumen. In a previous study, we confirmed enhancement of fiber digestion in a co-culture of F. succinogenes S85 with non-fibrolytic ruminal strains R-25 and/or Selenomonas ruminantium S137. In the present study, mRNA expression level of selected functional genes in the genome of F. succinogenes S85 was monitored by real-time RT-PCR. Growth profile of F. succinogenes S85 was similar in both the monoculture and co-cultures with non-fibrolytics. However, expression of 16S rRNA gene of F. succinogenes S85 in the co-culture was higher (P < 0.01) than that of the monoculture. This finding suggests that metabolic activity of F. succinogenes S85 was enhanced by coexistence with strains R-25 and/or S. ruminantium S137. The mRNA expression of fumarate reductase and glycoside hydrolase genes was up-regulated (P < 0.01) when F. succinogenes S85 was co-cultured with non-fibrolytics. These results indicate the enhancement of succinate production and fiber hydrolysis by F. succinogenes S85 in co-cultures of S. ruminantium and R-25 strains.
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan.
authors.forename: Naoki M
authors.initials: NM
authors.lastname: Fukuma
authors.forename: Satoshi
authors.initials: S
authors.lastname: Koike
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000254:growth & development; D018920:Coculture Techniques; D004043:Dietary Fiber / Q000378:metabolism; D045848:Fibrobacter / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006026:Glycoside Hydrolases / Q000235:genetics; D006868:Hydrolysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012417:Rumen / Q000382:microbiology; D013385:Succinate Dehydrogenase / Q000235:genetics
chemical_list: D004043:Dietary Fiber; D012336:RNA, Ribosomal, 16S; D013385:Succinate Dehydrogenase; D006026:Glycoside Hydrolases