Kawai F, Yamanaka H
Arch Microbiol. 1986 Nov;146(2):125-9. doi: 10.1007/BF00402338.
Neither Flavobacterium sp. nor Pseudomonas sp. grew on a polyethylene glycol (PEG) 6000 medium containing the culture filtrate of their mixed culture on PEG 6000. The two bacteria did not grow with a dialysis culture on a PEG 6000 medium. Flavobacterium sp. grew well on a dialysis culture containing a tetraethylene glycol medium supplemented with a small amount of PEG 6000 as an inducer, while poor growth of Pseudomonas sp. was observed. Three enzymes involved in the metabolism of PEG, PEG dehydrogenase, PEG-aldehyde dehydrogenase and PEG-carboxylate dehydrogenase (ether-cleaving) were present in the cells of Flavobacterium sp. The first two enzymes were not found in the cells of Pseudomonas sp. PEG 6000 was degraded neither by intact cells of Flavobacterium sp. nor by those of Pseudomonas sp., but it was degraded by their mixture. Glyoxylate, a metabolite liberated by the ether-cleaving enzyme, inhibited the growth of the mixed culture. The ether-cleaving enzyme was remarkably inhibited by glyoxylate. Glyoxylate was metabolized faster by Pseudomonas sp. than by Flavobacterium sp., and seemed to be a key material for the symbiosis.
在含有它们在聚乙二醇（PEG）6000上混合培养物滤液的聚乙二醇6000培养基中，黄杆菌属和假单胞菌属均未生长。这两种细菌在聚乙二醇6000培养基上进行透析培养时也未生长。黄杆菌属在含有添加少量聚乙二醇6000作为诱导剂的四甘醇培养基的透析培养物中生长良好，而假单胞菌属生长较差。黄杆菌属细胞中存在参与聚乙二醇代谢的三种酶，即聚乙二醇脱氢酶、聚乙二醇醛脱氢酶和聚乙二醇羧酸盐脱氢酶（醚裂解酶）。假单胞菌属细胞中未发现前两种酶。聚乙二醇6000既不被黄杆菌属的完整细胞降解，也不被假单胞菌属的完整细胞降解，但被它们的混合物降解。由醚裂解酶释放的代谢产物乙醛酸抑制混合培养物的生长。醚裂解酶受到乙醛酸的显著抑制。假单胞菌属比黄杆菌属更快地代谢乙醛酸，乙醛酸似乎是共生的关键物质。
