Norkrans B, Tunblad-Johansson I
Arch Microbiol. 1977 Nov 18;115(2):127-33. doi: 10.1007/BF00406365.
The cellular pool of Krebs cycle keto acids was followed as a function of growth in three yeasts. The keto acids were analyzed as silylated methoximes by quantitative gas chromatography with capillary glass columns. The 2-oxoglutaric acid content was strikingly high in the hydroxylamine (HA)-tolerant, HA-utilizing Endomycopsis lipolytica when compared to that in the nitrate-utilizing yeast Cryptococcus albidus and Saccharomyces cerevisiae, requiring fully reduced nitrogen for growth. The content of E. lipolytica increased throughout the log phase to maxima of about 200-250 microgram per g dry weight in HA and ammonia media. These amounts are 20-25 times greater than those attained in the two other yeasts. The cellular content of pyruvic acid was at a maximum early in the log phase, amounting to 50-70 microgram per g dry weight for all yeasts. The oxalacetic acid content never exceeded 9 microgram per g dry weight in any of the yeasts. Oximeformation, for which keto acid production is a prerequisite, is discussed as part of the HA-tolerance.
在三种酵母中，研究了三羧酸循环酮酸的细胞池随生长的变化情况。通过使用毛细管玻璃柱的定量气相色谱法，将酮酸分析为甲硅烷基化的甲氧肟。与利用硝酸盐的酵母白色隐球菌和酿酒酵母相比，耐羟胺（HA）、利用HA的解脂内孢霉中2-氧代戊二酸含量显著较高，后两者生长需要完全还原态氮。在对数生长期，解脂内孢霉中2-氧代戊二酸的含量持续增加，在HA和氨培养基中达到约200 - 250微克/克干重的最大值。这些含量比其他两种酵母中达到的含量高20 - 25倍。丙酮酸的细胞含量在对数生长期早期达到最大值，所有酵母中均为50 - 70微克/克干重。在任何酵母中，草酰乙酸含量从未超过9微克/克干重。酮酸生成是肟形成的前提条件，肟形成作为耐HA的一部分进行了讨论。
