Jin Wook, Kim Hyo Kyung, Kim Jae Young, Kang Sung Gyun, Lee Sang Hee, Lee Kye Joon
School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
J Biotechnol. 2004 Oct 19;114(1-2):81-7. doi: 10.1016/j.jbiotec.2004.06.010.
The effects of growth rate and nutrient uptake rate on the production of cephamycin C were determined in the parental strain, deltarelA mutant, and deltarsh null mutant of S. clavuligerus. Production of cephamycin C was inversely related to mycelium growth and the phosphate feed rate was more critical for the production of cephamycin C. On the contrary, the production of cephamycin C was completely abolished in the deltarelA mutant, but not in deltarsh mutant. The changes in the cephamycin C production by disruption of the relA and rsh genes are presumably associated with the consequent ability of the mutants to accumulate (p)ppGpp under nutrient starvation. Therefore, it is concluded that the stringent response of S. clavuligerus to starvation for nutrients is governed mainly by RelA rather than Rsh and that the response is more apparently regulated by the limitation of phosphate.
在棒状链霉菌的亲本菌株、ΔrelA突变体和Δrsh缺失突变体中，测定了生长速率和营养吸收速率对头孢霉素C产量的影响。头孢霉素C的产量与菌丝体生长呈负相关，磷酸盐进料速率对头孢霉素C的产量更为关键。相反，头孢霉素C的产量在ΔrelA突变体中完全消失，但在Δrsh突变体中并未消失。relA和rsh基因破坏导致的头孢霉素C产量变化可能与突变体在营养饥饿条件下积累（p）ppGpp的能力有关。因此，得出结论，棒状链霉菌对营养饥饿的严格反应主要由RelA而非Rsh控制，并且该反应更明显地受磷酸盐限制调节。
