Azuma Yoshinao, Hosoyama Akira, Matsutani Minenosuke, Furuya Naoko, Horikawa Hiroshi, Harada Takeshi, Hirakawa Hideki, Kuhara Satoru, Matsushita Kazunobu, Fujita Nobuyuki, Shirai Mutsunori
Department of Microbiology and Immunology, Yamaguchi University School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
Nucleic Acids Res. 2009 Sep;37(17):5768-83. doi: 10.1093/nar/gkp612. Epub 2009 Jul 28.
Acetobacter species have been used for brewing traditional vinegar and are known to have genetic instability. To clarify the mutability, Acetobacter pasteurianus NBRC 3283, which forms a multi-phenotype cell complex, was subjected to genome DNA sequencing. The genome analysis revealed that there are more than 280 transposons and five genes with hyper-mutable tandem repeats as common features in the genome consisting of a 2.9-Mb chromosome and six plasmids. There were three single nucleotide mutations and five transposon insertions in 32 isolates from the cell complex. The A. pasteurianus hyper-mutability was applied for breeding a temperature-resistant strain grown at an unviable high-temperature (42 degrees C). The genomic DNA sequence of a heritable mutant showing temperature resistance was analyzed by mutation mapping, illustrating that a 92-kb deletion and three single nucleotide mutations occurred in the genome during the adaptation. Alpha-proteobacteria including A. pasteurianus consists of many intracellular symbionts and parasites, and their genomes show increased evolution rates and intensive genome reduction. However, A. pasteurianus is assumed to be a free-living bacterium, it may have the potentiality to evolve to fit in natural niches of seasonal fruits and flowers with other organisms, such as yeasts and lactic acid bacteria.
醋酸杆菌属已被用于酿造传统食醋，并且已知其具有遗传不稳定性。为了阐明其变异性，对形成多表型细胞复合体的巴氏醋酸杆菌NBRC 3283进行了基因组DNA测序。基因组分析显示，在由一条2.9 Mb染色体和6个质粒组成的基因组中，共有280多个转座子和5个具有高度可变串联重复序列的基因。从细胞复合体的32个分离株中发现了3个单核苷酸突变和5个转座子插入。巴氏醋酸杆菌的高变异性被应用于培育一种能在不可行的高温（42摄氏度）下生长的耐温菌株。通过突变定位分析了一株具有遗传稳定性的耐温突变体的基因组DNA序列，结果表明在适应过程中基因组发生了92 kb的缺失和3个单核苷酸突变。包括巴氏醋酸杆菌在内的α-变形菌包含许多细胞内共生体和寄生虫，它们的基因组显示出更高的进化速率和强烈的基因组缩减。然而，巴氏醋酸杆菌被认为是一种自由生活的细菌，它可能有潜力与其他生物（如酵母和乳酸菌）一起进化，以适应季节性水果和花卉的自然生态位。
