Journal Article

The complete genome sequence of Lactobacillus bulgaricus reveals extensive and ongoing reductive evolution

Loux, Valentin, Unité Mathématique Informatique et Génome (MIG) ; Institut National de la Recherche Agronomique (INRA), Bayer CropScience [UK], Nicolas, Pierre, P, Barbe, Valérie, Centre National de la Recherche Scientifique (CNRS), Bryson, K, Maguin, Emmanuelle, Bossy, Robert, R, Dervyn, Rozenn, Bolotin, Alexandre, Unité de recherche Génétique Microbienne (UGM) ; Institut National de la Recherche Agronomique (INRA), Bessières, Philippe, Integrated Genomics Inc, Weissenbach, J, Gibrat, Jean-François, Penaud, Stéphanie, Couloux, A, Ehrlich, Stanislav, S, Batto, Jean-Michel, J.-M, Grimaldi, Christine, van de Guchte, Maarten, Walunas, T, Otzas, S, Unité de biométrie et intelligence artificielle de Jouy (MIA-JOUY) ; Institut National de la Recherche Agronomique (INRA), Mangenot, S

2006

Overview

Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) is a representative of the group of lactic acid-producing bacteria, mainly known for its worldwide application in yogurt production. The genome sequence of this bacterium has been determined and shows the signs of ongoing specialization, with a substantial number of pseudogenes and incomplete metabolic pathways and relatively few regulatory functions. Several unique features of the L. bulgaricus genome support the hypothesis that the genome is in a phase of rapid evolution. (i) Exceptionally high numbers of rRNA and tRNA genes with regard to genome size may indicate that the L. bulgaricus genome has known a recent phase of important size reduction, in agreement with the observed high frequency of gene inactivation and elimination; (ii) a much higher GC content at codon position 3 than expected on the basis of the overall GC content suggests that the composition of the genome is evolving toward a higher GC content; and (iii) the presence of a 47.5-kbp inverted repeat in the replication termination region, an extremely rare feature in bacterial genomes, may be interpreted as a transient stage in genome evolution. The results indicate the adaptation of L. bulgaricus from a plant-associated habitat to the stable protein and lactose-rich milk environment through the loss of superfluous functions and protocooperation with Streptococcus thermophilus.

• Publisher: National Academy of Sciences,CCSD,National Acad Sciences
• Subject: Adaptation / Bacteria / Bacterial Proteins - genetics / Bacterial Proteins - metabolism / Base Sequence / Biological Sciences / Biosynthesis / Carbohydrate Metabolism / Cellular Biology / cultured milk starters / Enzymes / Evolution / Evolution, Molecular / genes / genome / Genome size / Genome, Bacterial / Genomes / Genomics / Globular star clusters / Inactivation / Interspersed Repetitive Sequences / Lactobacillus bulgaricus / Lactobacillus delbrueckii / Lactobacillus delbrueckii - genetics / Lactobacillus delbrueckii - metabolism / Lactobacillus delbrueckii subsp. bulgaricus / Life Sciences / Molecular Sequence Data / nucleotide sequences / Pseudogenes / Replication origin / Ribonucleic acid / ribosomal RNA / RNA / Sequence Analysis, DNA / Streptococcus thermophilus / Streptococcus thermophilus - metabolism / Synteny / Transfer RNA / Yogurt / Yogurt - microbiology
• ISBN: 9780002383691, 0002383691