The global regulator csra of e . coli is a specific mrna - binding protein . csra negatively regulates several metabolic pathways that are induced post - exponentially , including glycogen biosynthesis , gluconeogenesis , and glycogen catabolism ; positively controls gene expression within the glycolytic pathway ; and also csra modulates the levels of enzymes that participate directly in pep metabolism Csra是整体调控网络的调控基因，可负调控指数生长后期诱导的一些代谢途径，包括糖原的生物合成、糖原的分解代谢、糖异生，而对糖酵解的一些重要基因的表达则执行正调控功能， csra也调控直接参与pep代谢的三个酶的活性水平。
Arginine feeding experiment showed that nitrogen metabolism in the s . tenebraius was obviously affected by arginine through two possible ways : ( l ) pronase activity in vitro could be influnced by arginine , as a result , the catabolism of nitrogen - containing macro - molecule was promoted and the nitrogen element in the broth was increased . ( 2 ) arginine could be transformed into glutamic acid , so that the biosynthesis of apramycin was promoted 因而我们认为gln可能是安普霉素生物合成氮元素的供体。 arg添加实验结果表明， arg可能通过两种途径影响黑暗链霉菌体内的氮代谢： ( 1 ) arg可能影响胞外蛋白酶的活性，进而促进含氮大分子物质的分解代谢，补充发酵过程中的氮素来源。
