title: Identification of Oxygen-Responsive Transcripts in the Silage Inoculant Lactobacillus buchneri CD034 by RNA Sequencing.
abstract: The Lactobacillus buchneri CD034 strain, known to improve the ensiling process of green fodder and the quality of the silage itself was transcriptionally analyzed by sequencing of transcriptomes isolated under anaerobic vs. aerobic conditions. L. buchneri CD034 was first cultivated under anaerobic conditions and then shifted to aerobic conditions by aeration with 21% oxygen. Cultivations already showed that oxygen was consumed by L. buchneri CD034 after aeration of the culture while growth of L. buchneri CD034 was still observed. RNA sequencing data revealed that irrespective of the oxygen status of the culture, the most abundantly transcribed genes are required for basic cell functions such as protein biosynthesis, energy metabolism and lactic acid fermentation. Under aerobic conditions, 283 genes were found to be transcriptionally up-regulated while 198 genes were found to be down-regulated (p-value < 0.01). Up-regulated genes i. a. play a role in oxygen consumption via oxidation of pyruvate or lactate (pox, lctO). Additionally, genes encoding proteins required for decomposition of reactive oxygen species (ROS) such as glutathione reductase or NADH peroxidase were also found to be up-regulated. Genes related to pH homeostasis and redox potential balance were found to be down-regulated under aerobic conditions. Overall, genes required for lactic acid fermentation were hardly affected by the growth conditions applied. Genes identified to be differentially transcribed depending on the aeration status of the culture are suggested to specify the favorable performance of the strain in silage formation.
authors.affiliation: Institute for Genome Research and Systems Biology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
authors.forename: Felix Gregor
authors.initials: FG
authors.lastname: Eikmeyer
authors.affiliation: CD Laboratory for Genetically Engineered Lactic Acid Bacteria, University of Natural Resources and Life Sciences, Vienna, Austria; Department of Biotechnology, BOKU-VIBT University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Heinl
authors.affiliation: CD Laboratory for Biotechnology of Glycerol, University of Natural Resources and Life Sciences, Vienna, Austria; Department of Biotechnology, BOKU-VIBT University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Hans
authors.initials: H
authors.lastname: Marx
authors.affiliation: Institute for Genome Research and Systems Biology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Pühler
authors.affiliation: CD Laboratory for Genetically Engineered Lactic Acid Bacteria, University of Natural Resources and Life Sciences, Vienna, Austria; Department of Biotechnology, BOKU-VIBT University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Reingard
authors.initials: R
authors.lastname: Grabherr
authors.affiliation: Institute for Genome Research and Systems Biology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schlüter
mesh_terms: D015536:Down-Regulation; D005798:Genes, Bacterial; D007778:Lactobacillus / Q000235:genetics* / Q000254:growth & development; D010100:Oxygen / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D017423:Sequence Analysis, RNA; D059467:Transcriptome; D015854:Up-Regulation
chemical_list: D012329:RNA, Bacterial; D012333:RNA, Messenger; D010100:Oxygen