Chitin is the second most abundant carbohydrate biopolymer present in soils and is utilized by antibiotic–producing Streptomyces species. Its monomer, N-acetylglucosamine (GlcNAc), regulates the developmental program of the model organism Streptomyces coelicolor. GlcNAc blocks differentiation when growing on rich medium whilst it promotes development on poor culture media. However, it is unclear if the same GlcNAc regulatory profile observed in S. coelicolor applies also to other industrially important Streptomyces species. We report here the negative effect of GlcNAc on differentiation and tacrolimus (FK506) production by Streptomyces tsukubaensis NRRL 18488. Using microarrays technology, we found that GlcNAc represses the transcription of fkbN, encoding the main transcriptional activator of the tacrolimus biosynthetic cluster, and of ppt1, encoding a phosphopantheteinyltransferase involved in tacrolimus biosynthesis. On the contrary, GlcNAc stimulated transcription of genes related to amino acid and nucleotide biosynthesis, DNA replication, RNA translation, glycolysis and pyruvate metabolism. The results obtained support those previously reported for S. coelicolor, but some important differences were observed; for example genes involved in GlcNAc transport and metabolism and genes encoding transcriptional regulators such as crr, ptsI, nagE1, nagE2, nagB, chiA, chiJ, ngcE, dasR or atrA are not significantly induced in S. tsukubaensis by GlcNAc addition. Differences in the GlcNAc transport systems, in the physiology of S. tsukubaensis and S. coelicolor and/or the different composition of the culture media used are likely to be responsible for the discrepancies observed between these species.

几丁质是土壤中第二大最丰富的碳水化合物生物聚合物，被生产抗生素的链霉菌利用。它的单体N-乙酰氨基葡萄糖（GlcNAc）调节模式生物天蓝色链霉菌（Streptomyces coelicolor）的发育程序。当在丰富的培养基上生长时，GlcNAc阻止分化，而在不良培养基上则促进发育。但是，尚不清楚是否在天蓝色链霉菌中观察到的相同的GlcNAc调控谱也适用于其他工业上重要的链霉菌种。我们在这里报告GlcNAc对筑波链霉菌的分化和他克莫司（FK506）生产的负面影响NRRL18488。使用微阵列技术，我们发现GlcNAc抑制了编码他克莫司生物合成簇的主要转录激活因子fkbN以及编码参与他克莫司生物合成的磷酸泛肽基转移酶ppt1的转录。相反，GlcNAc刺激了与氨基酸和核苷酸生物合成，DNA复制，RNA翻译，糖酵解和丙酮酸代谢有关的基因的转录。获得的结果支持先前报道的天蓝色链霉菌，但观察到一些重要差异。例如，涉及GlcNAc转运和代谢的基因，以及编码转录调节因子（例如crr，ptsI，nagE1，通过添加GlcNAc，在筑波链球菌中没有明显诱导nagE2，nagB，chiA，chiJ，ngcE，dasR或atrA。GlcNAc转运系统，筑波链球菌和腔肠链球菌的生理学差异和/或所用培养基的不同组成可能是造成这些物种之间差异的原因。