Metabolomic Functional Analysis of Bacterial Genomes: Final Report

[摘要] The availability of the complete DNA sequence of the bacterial genome of Nitrosomonas europaea offered the opportunity for unprecedented and detailed investigations of function. We studied the function of genes involved in carbohydrate and Fe metabolism. N. europaea has genes for the synthesis and degradation of glycogen and sucrose but cannot grow on substrates other than ammonia and CO2. Granules of glycogen were detected in whole cells by electron microscopy and quantified in cell-free extracts by enzymatic methods. The cellular glycogen and sucrose content varied depending on the composition of the growth medium and cellular growth stage. N. europaea also depends heavily on iron for metabolism of ammonia, is particularly interesting since it lacks genes for siderophore production, and has genes with only low similarity to known iron reductases, yet grows relatively well in medium containing low Fe. By comparing the transcriptomes of cells grown in iron-replete medium versus iron-limited medium, 247 genes were identified as differentially expressed. Mutant strains deficient in genes for sucrose, glycogen and iron metabolism were created and are being used to further our understanding of ammonia oxidizing bacteria.

[发布日期] 2008-01-01

[学科分类] 生物科学（综合）

[关键词] AMMONIA;AVAILABILITY;BACTERIA;CARBOHYDRATES;DNA;ELECTRON MICROSCOPY;FUNCTIONAL ANALYSIS;GENES;GLYCOGEN;IRON;METABOLISM;MUTANTS;OXIDOREDUCTASES;PRODUCTION;SACCHAROSE;STRAINS;SUBSTRATES;SYNTHESIS Nitrosomonas europaea;Nitrification;Metabolome