Thiamin in Bacterial Growth

Thiamin was first implicated in bacterial growth by Tatum, Wood, and Peterson (381) who observed that it had a marked growth-promoting effect on certain strains of propionic acid bacteria when added to a deficient basal medium. Not all the strains of propionic acid bacteria used required to be given thiamin some strains grew and fermented well on the basal medium alone still others did not respond to the addition of thiamin alone and evidently required an additional growth factor. 

For Staphylococcus aureus, thiamin (or its constituent pyrimidine and thiazole components together) was found by Knight to be an essential nutrient (155,156). Unlike the propionic acid bacteria, all the typical strains of Staph, aureus which have been examined (156, 289) drppear to need thiamin as an essential nutrient. No observations have been recorded of strains of Staph, aureus which can synthesize thiamin, as with the propionic and lactic acid bacteria such strains may yet be found. O Kane (273) records strains of Staph, flavus which grew in a simple ammonia medium without added growth factors. 

Niven and Smiley (272a) report that the intact thiamin molecule was required by 20 different strains of Streptococcus saiivarius co-carboxylase (thiamin diphosphate) was 40% more active than thiamin, on a molar basis. 

The part of thiamin in the nutrition of propionic acid bacteria was further illmninated by Wood, Andersen, and Werkman (435) and by Silverman and Werkman (346) who found it possible to train certain strains, which ori ally required the addition of thiamin, to dispense with this substance and to give vigorous and continued growth on a basal medium not containing it. Serial transfer in a medium deficient in thiamin was the method 

In the case of Staph, aureus no evidence of such training to synthesize thiamin has been recorded. Hills (127), in his study of pyruvate metabolism by Staph, aureus, grew his organisms in minimal concentrations of thiamin and was thus able to obtain thiamin-deficient cells rvhich showed sharp responses to the addition of thiamin in metabolism experiments. If the organisms he used had shown a tendency to synthesize thiamin under these 

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