title: Bacterial community dynamics in a rumen fluid bioreactor during in-vitro cultivation.
abstract: To study the various processes in the rumen the in vitro techniques are widely used to realize more controlled and reproducible conditions compared to in vivo experiments. Mostly, only the parameters like pH changes, volatile fatty acids content or metabolite production are monitored. In this study we examine the bacterial community dynamics of rumen fluid in course of ten day cultivation realize under standard conditions described in the literature. Whereas the pH values, total VFA content and A/P ratio in bioreactor were consistent with natural conditions in the rumen, the mean redox-potential values of -251 and -243mV were much more negative. For culture-independent assessment of bacterial community composition, the Illumina MiSeq results indicated that the community contained 292 bacterial genera. In course of ten days cultivation a significant changes in the microbial community were measured when Bacteroidetes to Firmicutes ratio changed from 3.2 to 1.2 and phyla Proteobacteria and Actinobacteria represented by genus Bifidobacterium and Olsenella significantly increased. The main responsible factor of these changes seems to be very low redox potential in bioreactor together with accumulation of simple carbohydrates in milieu as a result of limited excretion of fermented feed and absence of nutrient absorbing mechanisms.
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Zapletalová
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Kašparovská
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Křížová
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Kašparovský
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
authors.forename: Omar
authors.initials: O
authors.lastname: Šerý
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic. Electronic address: lochik@mail.muni.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Lochman
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D041963:Bacteroidetes / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D019149:Bioreactors / Q000382:microbiology*; D002417:Cattle; D004269:DNA, Bacterial; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D000068536:Bacillota / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D064307:Microbiota / Q000235:genetics; D010084:Oxidation-Reduction; D020560:Proteobacteria / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012417:Rumen / Q000378:metabolism / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D005232:Fatty Acids, Volatile; D012336:RNA, Ribosomal, 16S
keywords: 16S rDNA; Bioreactor; Microbiome analysis; Redox potential; Rumen fluid