Bacterial extracellular aminopeptidases are key enzymes in protein processing in oligotrophic seawater. To the best of our knowledge, the regulation of aminopeptidase production in microbes inhabiting seawater has not yet been reported. The present study attempted to experimentally clarify which organic materials affect bacterial extracellular aminopeptidase production by nutrient-rich and starved cells growing in artificial seawater using Photobacterium, Alteromonas, Ruegeria, and Sulfitobacter. In all four species, we found that peptides induced bacterial extracellular aminopeptidase production. Amino acids led to cell growth with markedly lower aminopeptidase production by Photobacterium and Sulfitobacter, but not by Alteromonas and Ruegeria. These results suggest that the extracellular aminopeptidases of marine bacteria are primarily produced on demand in response to the presence of relevant substrates (peptides) in seawater. Peptidyl substances may be regulatory nutrients for marine bacterial growth in aquatic environments.

中文翻译：

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在一些海洋细菌物种中通过肽诱导细胞外氨肽酶的产生。

细菌胞外氨肽酶是寡营养海水中蛋白质加工的关键酶。据我们所知，尚无关于生活在海水中的微生物中氨肽酶产生的调节的报道。本研究试图通过使用光杆菌、交替单胞菌、Ruegeria 和 Sulfitobacter 实验阐明哪些有机材料影响在人工海水中生长的营养丰富和饥饿细胞产生的细菌胞外氨肽酶。在所有四个物种中，我们发现肽诱导细菌细胞外氨肽酶的产生。氨基酸导致细胞生长，光杆菌和亚硫酸杆菌产生的氨肽酶明显降低，但交替单胞菌和 Ruegeria 则不然。这些结果表明，海洋细菌的胞外氨肽酶主要是根据海水中相关底物（肽）的存在按需产生的。肽基物质可能是水生环境中海洋细菌生长的调节营养素。