Kelleher Philip, Bottacini Francesca, Mahony Jennifer, Kilcawley Kieran N, van Sinderen Douwe
School of Microbiology, University College Cork, Cork, Ireland.
Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
BMC Genomics. 2017 Mar 29;18(1):267. doi: 10.1186/s12864-017-3650-5.
Lactococcus lactis is among the most widely studied lactic acid bacterial species due to its long history of safe use and economic importance to the dairy industry, where it is exploited as a starter culture in cheese production.
In the current study, we report on the complete sequencing of 16 L. lactis subsp. lactis and L. lactis subsp. cremoris genomes. The chromosomal features of these 16 L. lactis strains in conjunction with 14 completely sequenced, publicly available lactococcal chromosomes were assessed with particular emphasis on discerning the L. lactis subspecies division, evolution and niche adaptation. The deduced pan-genome of L. lactis was found to be closed, indicating that the representative data sets employed for this analysis are sufficient to fully describe the genetic diversity of the taxon.
Niche adaptation appears to play a significant role in governing the genetic content of each L. lactis subspecies, while (differential) genome decay and redundancy in the dairy niche is also highlighted.
乳酸乳球菌因其安全使用历史悠久且对乳制品行业具有经济重要性，是研究最为广泛的乳酸菌物种之一，在奶酪生产中被用作发酵剂。
在本研究中，我们报告了16株乳酸乳球菌乳酸亚种和乳酸乳球菌乳脂亚种基因组的完整测序情况。结合14条已完全测序且公开可用的乳球菌染色体，对这16株乳酸乳球菌菌株的染色体特征进行了评估，特别着重于辨别乳酸乳球菌亚种的划分、进化和生态位适应性。发现乳酸乳球菌的推导泛基因组是封闭的，这表明用于该分析的代表性数据集足以充分描述该分类单元的遗传多样性。
生态位适应性似乎在决定每个乳酸乳球菌亚种的遗传内容方面发挥着重要作用，同时也凸显了乳制品生态位中的（差异）基因组衰退和冗余现象。
