Ocean science must evolve to meet social challenges in the seafood sector

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on the life cycle of bacteria, that a single species of Azotobacter may pass through as many as twelve to fourteen morphological forms including spores, is not particularly relevant with respect to Bad. coli, the life cycle of which has been carefully studied by Kellerman and Scales who note specifically that spores were not observed. It is conceivable that unfavorable environment may lead to spore formation by members of the colonjerogenes group but the writer has never encountered nor heard of such a transformation, although he has observed a large number of cultures kept under various unfavorable conditions, nor does he anticipate such a fundamental and radical change in form. These spore forming, aerobic, lactose fermenters confuse the ordinary tests for Bact. coli and must be taken into consideration in interpreting water analyses, just as it is essential to differentiate the anaerobic spore forming lactose fermenters which confuse, the presumptive test for Bact. coli, but there is no logical reason nor justification for placing them in the colon group. Clark and Lubs raise the question as to the reliability of lactose fermentation as a primary criterion. They say, "If a fundamental cultural requirement of the members of the colon-aerogenes family is that it shall ferment lactose, there is imposed the same sort of requirement for the characterization of a whole family as is imposed by the MacConkey scheme when groups within the family are separated on the basis of the fermentation of another sugar, sucrose." They point out that the fermentation of sucrose, which was formerly employed to subdivide the colon group into species and varieties (Mac-Conkey's scheme), has been found less desirable than differentation on more recently devised tests, such as the gas ratio, the methyl-red reaction, and the Voges Proskauer test. They raise the question as to whether it is not possible that in the near future a test may be discovered which will supplant lactose fermentation as the salient and fundamental requirement for the whole colon-aerogenes family. We may well agree with Clark and Lubs that the future holds out to us promises of improved differential tests but we do not feel that, in consequence, we shall not utilize such means as are now available. Surely the classification of the organisms of this group to the best of our abiltiy on tests which are now known and used, would simplify a reclassification when these more fundamental, and we hope more reliable reactions of the future are brought out. The fact remains that the fermentation of lactose has been successfully employed for the separation of the non-pathogenic colon group from the disease producing para-typhoid and typhoid groups. Until a test is developed which will adequately supplant this, the fermentation of lactose with acid and gas production is considered a convenient and reasonably reliable criterion for members of the colon group of bacteria. The colon group will therefore be considered to include non-sporing, Gram negative bacilli which ferment lac...