Hayes A, Hobbs G, Smith C P, Oliver S G, Butler P R
Department of Biomolecular Sciences, UMIST, Manchester, United Kingdom.
J Bacteriol. 1997 Sep;179(17):5511-5. doi: 10.1128/jb.179.17.5511-5515.1997.
Methylenomycin production by Streptomyces coelicolor A3(2) may be triggered by either of two environmental signals: alanine growth-rate-limiting conditions and/or an acidic pH shock. The production of this SCP1-encoded antibiotic was studied by using batch and chemostat cultures. Batch cultures indicated a role for both nutritional status and culture pH in its regulation. Steady-state methylenomycin production and transcription of an mmy gene under alanine but not glucose growth-rate-limiting conditions was demonstrated in chemostat culture. Transient mmy expression and methylenomycin production occurred following an acidic pH shock. This stimulation of methylenomycin production occurred independently of the nutritional status of the growth environment. Antibiotic production was partially suppressed under alanine compared with glucose growth-rate-limiting conditions following the acidic pH shock. A low specific growth rate was a prerequisite for both steady-state and transient production of methylenomycin.
天蓝色链霉菌A3(2)产生亚甲基霉素可能由两种环境信号中的任何一种触发:丙氨酸生长速率限制条件和/或酸性pH冲击。通过分批培养和恒化器培养研究了这种由SCP1编码的抗生素的产生。分批培养表明营养状态和培养pH在其调控中均起作用。在恒化器培养中,证实了在丙氨酸而非葡萄糖生长速率限制条件下,亚甲基霉素的稳态产生以及mmy基因的转录。酸性pH冲击后会出现短暂的mmy表达和亚甲基霉素产生。亚甲基霉素产生的这种刺激独立于生长环境的营养状态。在酸性pH冲击后,与葡萄糖生长速率限制条件相比,在丙氨酸条件下抗生素产生受到部分抑制。低比生长速率是亚甲基霉素稳态和瞬时产生的先决条件。