Department of Genetics and Microbiology, Life Sciences Building, The University of Liverpool, Crown Street, Liverpool L69 3BX, United Kingdom.
Appl Environ Microbiol. 1990 Mar;56(3):675-80. doi: 10.1128/aem.56.3.675-680.1990.
Actinorhodin production by Streptomyces coelicolor was used as a model system to study the effects of metals on growth and polyketide synthesis in a streptomycete. Numerous metals were tested in cultures grown in liquid media. Mercury and cadmium were highly toxic, and copper, nickel, and lead were less so, but all tended to inhibit both growth and antibiotic synthesis to a similar extent. Unexpectedly, manganese, cobalt, zinc, and, to a lesser extent, chromium caused complex effects that in general resulted in some enhancement of growth yield but a reduction in antibiotic titers. These complex effects meant that cobalt, manganese, and zinc had lower 50% inhibitory concentrations for antibiotic yields compared with those for biomass. The physiologically active divalent cations calcium and magnesium were also tested. Calcium at high concentrations was particularly effective in reducing antibiotic titers and enhancing growth yields. By adding calcium at different phases of growth, it could be demonstrated that it was most effective in reducing the antibiotic yield when added during the early growth phase. Addition during the antibiotic-producing phase resulted in little reduction of final actinorhodin titers.
以变铅青链霉菌产生放线紫红素为模型系统，研究金属对链霉菌生长和聚酮合成的影响。在液体培养基中培养的细菌中测试了许多金属。汞和镉毒性很高，铜、镍和铅毒性较低，但它们都倾向于以相似的程度抑制生长和抗生素合成。出乎意料的是，锰、钴、锌，以及在较小程度上的铬，引起了复杂的影响，通常导致生长产量略有提高，但抗生素效价降低。这些复杂的影响意味着与生物量相比，钴、锰和锌的抗生素产量的 50%抑制浓度更低。还测试了生理活性的二价阳离子钙和镁。高浓度的钙特别有效地降低抗生素效价并提高生长产量。通过在不同的生长阶段添加钙，可以证明在早期生长阶段添加时，它最有效地降低抗生素的产量。在抗生素产生阶段添加时，最终放线紫红素效价的减少很小。
