THYMIDINE ENHANCEMENT FACTOR FOR THE GROWTH OF PEDIOCOCCUS CEREVISIAE 8081

Abstract

It was found that Pediococcus cerevisiae ATCC 8081 can grow and produce acid on μg amounts of thymidine instead of mμg amounts of folinic acid SF (citrovorum factor) to a considerably better extent with a "thymidine enhancement factor".
The "factor" present in some microbiological media was identified as an effect of Tween 80 present in the medium. Similar effect was obtained also by other non-toxic detergents and was considered to be surface tension lowering, since it was (a) unspecific for the chemical nature of the "factor" (b) of the "all-or-none" type (c) dependent on a defined water/liquid interfacial tension.
The bearing of changes in surface tension of the environment causing selective nutritional effects was discussed.