Bhatnagar N B
Institute of Microbial Technology, Chandigarh, India.
Biochem Int. 1990 Nov;22(4):781-90.
Growth of yeast cells in molasses caused changes in plasma membrane properties. The polypeptide profile of plasma membrane prepared by sucrose density gradient centrifugation showed a range of new polypeptides above 55 kD which were not present in malt extract-glucose-yeast extract-peptone medium grown cells. Isolated new bands appeared in the range of 25-50 kD. Transport of glucose was markedly enhanced in molasses trained cells. Among the amino acids, L-lysine uptake was decreased while L-aspartate uptake was enhanced considerably. Finally the metallothionein levels in the cells grown in molasses was found to be increased significantly, possibly to protect the cells from the harmful effect of heavy metal ions.
酵母细胞在糖蜜中生长会导致质膜特性发生变化。通过蔗糖密度梯度离心制备的质膜的多肽图谱显示，在55 kD以上出现了一系列新的多肽，而在麦芽提取物 - 葡萄糖 - 酵母提取物 - 蛋白胨培养基中生长的细胞中不存在这些多肽。在25 - 50 kD范围内出现了分离的新条带。在经糖蜜驯化的细胞中，葡萄糖的转运显著增强。在氨基酸中，L-赖氨酸的摄取减少，而L-天冬氨酸的摄取显著增加。最后发现，在糖蜜中生长的细胞中金属硫蛋白水平显著升高，这可能是为了保护细胞免受重金属离子的有害影响。
