RESUMO
Penicillium chrysogenum uses sulfate as a source of sulfur for the biosynthesis of penicillin. Sulfate uptake and the mRNA levels of the sulfate transporter-encoding sutB and sutA genes are all reduced by high sulfate concentrations and are elevated by sulfate starvation. In a high-penicillin-yielding strain, sutB is effectively transcribed even in the presence of excess sulfate. This deregulation may facilitate the efficient incorporation of sulfur into cysteine and penicillin.
Assuntos
Proteínas de Transporte de Ânions , Proteínas de Transporte/genética , Proteínas de Transporte de Cátions , Proteínas Fúngicas , Penicillium chrysogenum/genética , Sulfatos/metabolismo , Proteínas de Transporte/metabolismo , Penicillium chrysogenum/metabolismoRESUMO
Mycelium of Pleurotus ostreatus var. florida with a decreased growth rate contained seven double-stranded RNA segments and isometrical virus particles with diameters of 24 and 30 nm. Mycelium with a normal growth rate lacked dsRNA. Protoclones from virus-containing mycelium contained one to seven of these dsRNA segments in varying concentrations. The exact correlation between slow growth and the presence of dsRNA molecules could not be established. Infection of virus-free protoplasts with PEG-precipitated virus particles resulted in mycelium that stably maintained the 2.4 kbp dsRNA.