Schaeffer T L, Cantwell S G, Brown J L, Watt D S, Fall R R
Appl Environ Microbiol. 1979 Oct;38(4):742-6. doi: 10.1128/aem.38.4.742-746.1979.
A variety of octane-utilizing bacteria and fungi were screened for growth on some terminally branched dimethyloctane derivatives to explore the effects of iso- and anteiso-termini on the biodegradability of such hydrocarbons. Of 27 microbial strains tested, only 9 were found to use any of the branched hydrocarbons tested as a sole carbon source, and then only those hydrocarbons containing at least one iso-terminus were susceptible to degradation. Anteiso-or isopropenyl termini prevented biodegradation. None of the hydrocarbonoclastic yeasts tested was able to utilize branched-hydrocarbon growth sustrates. In the case of pseudomonads containing the OCT plasmid, whole-cell oxidation of n-octane was poorly induced by terminally branched dimethyloctanes. In the presence of a gratuitous inducer of the octane-oxidizing enzymes, the iso-branched 2,7-dimethyloctane was slowly oxidized by whole cells, whereas the anteiso-branched 3,6-dimethyloctane was not oxidized at all. This microbial sampling dramatically illustrated the deleterious effect of alkyl branching, especially anteiso-terminal branching, on the biodegradation of hydrocarbons.
筛选了多种利用辛烷的细菌和真菌，研究它们在一些末端分支的二甲基辛烷衍生物上的生长情况，以探究异末端和反异末端对这类碳氢化合物生物降解性的影响。在测试的27种微生物菌株中，仅发现9种能够将所测试的任何一种分支碳氢化合物用作唯一碳源，而且只有那些含有至少一个异末端的碳氢化合物才易于降解。反异末端或异丙烯基末端会阻止生物降解。所测试的烃分解酵母均无法利用分支碳氢化合物生长底物。对于含有OCT质粒的假单胞菌，末端分支的二甲基辛烷对正辛烷的全细胞氧化诱导作用较差。在存在辛烷氧化酶的 gratuitous诱导剂的情况下，异分支的2,7-二甲基辛烷被全细胞缓慢氧化，而反异分支的3,6-二甲基辛烷根本不被氧化。这种微生物采样显著说明了烷基分支，尤其是反异末端分支，对碳氢化合物生物降解的有害影响。
