Biosynthesis of beta-lactam antibiotics by fungi and actinomycetes is markedly affected by compounds containing nitrogen. The different processes employed by the spectrum of microbes capable of making these valuable compounds are affected differently by particular compounds. Ammonium ions, except at very low concentrations, exert negative effects via nitrogen metabolite repression, sometimes involving the nitrogen regulatory gene nre. Certain amino acids are precursors or inducers, whereas others are involved in repression and, in certain cases, as inhibitors of biosynthetic enzymes and of enzymes supplying precursors. The most important amino acids from the viewpoint of regulation are lysine, methionine, glutamate and valine. Surprisingly, diamines such as diaminopropane, putrescine and cadaverine induce cephamycin production by actinomycetes. In addition to penicillins and cephalosporins made by fungi and cephamycins made by actinomycetes, other beta-lactams are made by actinomycetes and unicellular bacteria. These include clavams (e.g., clavulanic acid), carbapenems (e.g., thienamycin), nocardicins and monobactams. Here also, amino acids are precursors and inhibitors, but only little is known about regulation. In the case of the simplest carbapenem made by unicellular bacteria, i.e., 1-carba-2-em-3-carboxylic acid, quorum sensors containing homoserine lactone are inducers.

中文翻译：

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含氮化合物参与β-内酰胺的生物合成及其控制。

真菌和放线菌对β-内酰胺抗生素的生物合成受到含氮化合物的显着影响。能够制造这些有价值的化合物的微生物谱所采用的不同方法受特定化合物的影响不同。除极低浓度的铵离子外，铵离子通过氮代谢物阻抑而产生负面影响，有时涉及氮调节基因nre。某些氨基酸是前体或诱导物，而其他氨基酸则参与抑制作用，在某些情况下，还可以作为生物合成酶和供应前体酶的抑制剂。从调节的角度来看，最重要的氨基酸是赖氨酸，蛋氨酸，谷氨酸和缬氨酸。令人惊讶地，二胺例如二氨基丙烷，腐胺和尸胺诱导了放线菌产生的头霉素。除了由真菌制成的青霉素和头孢菌素以及由放线菌制成的头孢菌素外，其他β-内酰胺是由放线菌和单细胞细菌制成的。这些包括蛤lava（例如，克拉维酸），碳青霉烯（例如，噻菌霉素），诺卡汀和单bactams。氨基酸在这里也是前体和抑制剂，但对调节的了解很少。对于单细胞细菌最简单的碳青霉烯，即1-carba-2-em-3-羧酸，含有高丝氨酸内酯的群体传感器是诱导剂。氨基酸是前体和抑制剂，但对调节知之甚少。对于单细胞细菌最简单的碳青霉烯，即1-carba-2-em-3-羧酸，含有高丝氨酸内酯的群体传感器是诱导剂。氨基酸是前体和抑制剂，但对调节知之甚少。对于单细胞细菌最简单的碳青霉烯，即1-carba-2-em-3-羧酸，含有高丝氨酸内酯的群体传感器是诱导剂。