EVIDENCE FOR THE OCCURRENCE OF PERMEASES FOR TRICARBOXYLIC ACID CYCLE INTERMEDIATES IN PSEUDOMONAS-AERUGINOSA
EVIDENCE FOR THE OCCURRENCE OF PERMEASES FOR TRICARBOXYLIC ACID CYCLE INTERMEDIATES IN PSEUDOMONAS-AERUGINOSA
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DOI：
10.1099/00221287-20-1-144
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发表时间：
1959-01-01
期刊：
影响因子：
--
通讯作者：
MEADOW, PM
中科院分区：
文献类型：
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作者：
CLARKE, PH;MEADOW, PM
测定了生长在Lemco琼脂上的铜绿假单胞菌的洗涤悬浮液和无细胞提取物对琥珀酸、富马酸、苹果酸、丙酮酸、乙酸酯、[α]-氧戊二酸和柠檬酸的氧化能力。除了在生长介质中添加柠檬酸盐或醋酸盐外，整个微生物在柠檬酸盐被迅速氧化之前有2-3小时的滞后期。生长在醋酸盐上的微生物对琥珀酸的快速线性氧化；生长在醋酸盐或丙酮酸上的微生物对富马酸的快速线性氧化；以及生长在苹果酸、丙酮酸、[α]-草戊二酸、富马酸或琥珀酸上的微生物对醋酸酯的快速和线性氧化之前，有大约10分钟的滞后期。在任何被测试的底物上生长的微生物对苹果酸、丙酮酸和[α]-草戊二酸的丙酮酸没有滞后。在没有添加任何添加剂的Lemco琼脂丙二酸酯上生长的微生物对所有底物都是滞后的。除琥珀酸外，葡萄糖生物对所有中间体都有滞后性。只有生长有丙二酸的生物体快速线性地氧化丙二酸，而没有丙二酸生长的生物体在氧化该底物之前有2-3小时的滞后时间。在柠檬酸、醋酸盐、富马酸、苹果酸、琥珀酸和[α]-草戊二酸氧化前有滞后期的生物的无细胞提取物被证明氧化这些底物而没有滞后期。丙酮酸和丙二酸不被任何提取物氧化，包括生长在这些底物上的生物体的提取物。氯霉素抑制了整个生物对底物的适应，但对无细胞提取物的氧化没有影响。讨论了这些发现与有机分子进入细胞的特定渗透率假说有关的意义。
Washed suspensions and cell-free extracts of Pseudomonas aeruginosa grown on Lemco agar, to which intermediates of the tricarboxylic acid cycle had been added, were tested for their ability to oxidize succinate, fumarate, malate, pyruvate, acetate, [alpha]-oxoglutarate and citrate. Whole organisms had lag periods of 2-3 hour before citrate was oxidized rapidly, except when citrate or acetate had been added to the growth medium. There were lag periods of about 10 minutes before rapid and linear oxidation of succinate by organisms grown on acetate; of fumarate by organisms grown on acetate or pyruvate; and of acetate by organisms grown on malate, pyruvate, [alpha]-oxoglutarate, fumarate or succinate. There were no lags for malate, pyruvate of [alpha]-oxoglutarate by organisms grown on any of the substrates tested. Organisms grown on malonate of Lemco agar to which no additions had been made had lags for all the substrates. Glucose-grown organisms had lags for all the intermediates except succinate. Only malonate-grown organisms oxidized malonate rapidly and linearly, and organisms grown without malonate had lag periods of 2-3 hour before oxidizing this substrate. Cell-free extracts from organisms with lag periods before the oxidation of citrate, acetate, fumarate, malate, succinate and [alpha]-oxoglutarate were shown to oxidize these substrates without a lag period. Pyruvate and malonate were not oxidized by any of the extracts including those from organism grown on these substrates. Chloramphenical inhibited the adaptation to substrates by whole organisms but was without effect on the oxidation by cell-free extracts. The significance of these findings in relation to the hypothesis of specific permeases for the transport of organic molecules into the cell is discussed.