Department of Microbiology and Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Cluster of Excellence 'Controlling Microbes to Fight Infections', University of Tübingen, Tübingen, Germany.
Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
Microb Physiol. 2021;31(3):233-247. doi: 10.1159/000516644. Epub 2021 May 27.
Soil bacteria from the genus Streptomyces, phylum Actinobacteria, feature a complex metabolism and diverse adaptations to environmental stress. These characteristics are consequences of variable nutrition availability in the soil and allow survival under changing nitrogen conditions. Streptomyces coelicolor is a model organism for Actinobacteria and is able to use nitrogen from a variety of sources including unusual compounds originating from the decomposition of dead plant and animal material, such as polyamines or monoamines (like ethanolamine). Assimilation of nitrogen from these sources in S. coelicolor remains largely unstudied. Using microbiological, biochemical and in silico approaches, it was recently possible to postulate polyamine and monoamine (ethanolamine) utilization pathways in S. coelicolor. Glutamine synthetase-like enzymes (GS-like) play a central role in these pathways. Extensive studies have revealed that these enzymes are able to detoxify polyamines or monoamines and allow the survival of S. coelicolor in soil containing an excess of these compounds. On the other hand, at low concentrations, polyamines and monoamines can be utilized as nitrogen and carbon sources. It has been demonstrated that the first step in poly-/monoamine assimilation is catalyzed by GlnA3 (a γ-glutamylpolyamine synthetase) and GlnA4 (a γ-glutamylethanolamide synthetase), respectively. First insights into the regulation of polyamine and ethanolamine metabolism have revealed that the expression of the glnA3 and the glnA4 gene are controlled on the transcriptional level.
土壤放线菌属链霉菌中的细菌，其特征在于复杂的代谢和对环境胁迫的多样适应。这些特征是土壤中可变营养供应的结果，使它们能够在不断变化的氮条件下生存。变铅青链霉菌是放线菌的模式生物，能够利用各种氮源，包括来自动植物尸体分解的不寻常化合物，如多胺或单胺（如乙醇胺）。在变铅青链霉菌中，从这些来源同化氮的过程在很大程度上仍未得到研究。最近，通过微生物学、生物化学和计算机模拟方法，我们可以推测出变铅青链霉菌中多胺和单胺（乙醇胺）的利用途径。谷氨酰胺合成酶样酶（GS-like）在这些途径中发挥着核心作用。广泛的研究表明，这些酶能够解毒多胺或单胺，使变铅青链霉菌能够在含有这些化合物过量的土壤中存活。另一方面，在低浓度下，多胺和单胺可以作为氮源和碳源被利用。已经证明，多/单胺同化的第一步分别由 GlnA3（γ-谷氨酰多胺合成酶）和 GlnA4（γ-谷氨酰乙醇胺合成酶）催化。对多胺和乙醇胺代谢调控的初步研究表明，glnA3 和 glnA4 基因的表达受转录水平的控制。
