Sánchez Norma Silvia, Arreguín Roberto, Calahorra Martha, Peña Antonio
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, México, D.F., Mexico.
FEMS Yeast Res. 2008 Dec;8(8):1303-12. doi: 10.1111/j.1567-1364.2008.00426.x. Epub 2008 Aug 20.
Debaryomyces hansenii was grown in YPD medium without or with 1.0 M NaCl or KCl. Respiration was higher with salt, but decreased if it was present during incubation. However, carbonylcyanide-3-chlorophenylhydrazone (CCCP) markedly increased respiration when salt was present during incubation. Salt also stimulated proton pumping that was partially inhibited by CCCP; this uncoupling of proton pumping may contribute to the increased respiratory rate. The ADP increase produced by CCCP in cells grown in NaCl was similar to that observed in cells incubated with or without salts. The alternative oxidase is not involved. Cells grown with salts showed increased levels of succinate and fumarate, and a decrease in isocitrate and malate. Undetectable levels of citrate and low-glutamate dehydrogenase activity were present only in NaCl cells. Both isocitrate dehydrogenase decreased, and isocitrate lyase and malate synthase increased. Glyoxylate did not increase, indicating an active metabolism of this intermediary. Higher phosphate levels were also found in the cells grown in salt. An activation of the glyoxylate cycle results from the salt stress, as well as an increased respiratory capacity, when cells are grown with salt, and a 'coupling' effect on respiration when incubated in the presence of salt.
汉逊德巴利酵母在不含或含有1.0 M氯化钠或氯化钾的YPD培养基中培养。有盐存在时呼吸作用增强，但如果在培养期间存在盐，呼吸作用会下降。然而，当在培养期间存在盐时，羰基氰化物-3-氯苯腙（CCCP）显著增加呼吸作用。盐还刺激质子泵浦，而质子泵浦会被CCCP部分抑制；这种质子泵浦的解偶联可能导致呼吸速率增加。CCCP在氯化钠中生长的细胞中产生的ADP增加与在有盐或无盐培养的细胞中观察到的相似。替代氧化酶不参与其中。用盐培养的细胞中琥珀酸和富马酸水平增加，而异柠檬酸和苹果酸水平降低。仅在氯化钠培养的细胞中检测不到柠檬酸盐水平且谷氨酸脱氢酶活性较低。两种异柠檬酸脱氢酶均降低，而异柠檬酸裂解酶和苹果酸合酶增加。乙醛酸没有增加，表明这种中间产物的代谢活跃。在盐中生长的细胞中也发现了较高的磷酸盐水平。当细胞用盐培养时，盐胁迫导致乙醛酸循环激活以及呼吸能力增强，并且在有盐存在的情况下培养时对呼吸作用产生“偶联”效应。
