Murugkar Pallavi, Dimise Eric, Stewart Eric, Viala Stéphane N, Clardy Jon, Dewhirst Floyd E, Lewis Kim
Antimicrobial Discovery Center, Department of Biology, Northeastern University, 134 Mugar Hall, 360 Huntington Ave 02115, Boston, MA, USA.
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School 02115, Boston, MA, USA.
J Oral Microbiol. 2022 Nov 25;15(1):2143651. doi: 10.1080/20002297.2022.2143651. eCollection 2023.
The aim of this research was to isolate oral bacteria that are dependent for growth on adjacent bacteria producing a required growth factor and to identify the chemical structure of the growth factor.
strain KLE1280, could be cultivated with and as helper strains. A deletion mutant library of E. coli was screened to determine genes involved in production of the growth factor. Compounds produced by the growth factor's pathway were screened to see if they would stimulate growth of strain KLE1280. The genomes of species related to KLE1280 were screened for presence of the factor's synthetic pathway.
Analysis of the deletion mutant library and growth studies identified 1,2-dihydroxy-2-naphthoic acid (DHNA) and menaquinone-4 (MK4) as the growth factors. Strain KLE1280 was shown to lack five genes in the menaquinone synthesis pathway but to possess the two genes necessary to convert DHNA to menaquinone. Genome analysis found that 8 species in genera and lack five genes in the menaquinone synthesis pathway.
Addition of DHNA to culture media allows isolation of strains of several oral species that are not recovered using standard media.
本研究的目的是分离出依赖相邻产生必需生长因子的细菌而生长的口腔细菌，并鉴定该生长因子的化学结构。
菌株KLE1280可与[具体菌株1]和[具体菌株2]作为辅助菌株进行培养。筛选大肠杆菌的缺失突变体文库以确定参与生长因子产生的基因。筛选生长因子途径产生的化合物，看它们是否能刺激菌株KLE1280的生长。筛选与KLE1280相关物种的基因组中生长因子合成途径的存在情况。
对缺失突变体文库的分析和生长研究确定1,2 - 二羟基 - 2 - 萘甲酸（DHNA）和甲基萘醌 - 4（MK4）为生长因子。菌株KLE1280在甲基萘醌合成途径中显示缺少五个基因，但拥有将DHNA转化为甲基萘醌所需的两个基因。基因组分析发现[具体属1]和[具体属2]中的8个物种在甲基萘醌合成途径中缺少五个基因。
在培养基中添加DHNA可分离出几种使用标准培养基无法回收的口腔物种菌株。
