NUTRITIONAL STUDIES WITH LACTOBACILLUS FERMENTI

Abstract

Asparagus juice concentrate and certain other plant products are highly stimulatory to L. fermenti, strain 36, on unheated medium. The effect is most apparent with a light inoculum and a short incubation period. Approx. 70% of the stimulation may be provided by heating the medium. Glucose reaction products (fructose plus reducing agents) simulate the stimulation due to heat. Replacement of glucose in the medium by maltose, fructose, and cysteine permits growth equalling that obtained with asparagus concentrate although such a medium does not represent a duplication of the composition of the asparagus concentrate. Either maltose or fructose alone permits more rapid growth than does glucose, and the presence of fructose permits more rapid growth on either maltose or glucose. The addition of reducing agents facilitates growth on fructose and maltose most markedly. The condition of the inoculum is also important. The improved growth on maltose, as compared with glucose, and its inhibition by glucose indicate that L. fermenti, like numerous other organisms, attacks the oligo-saccharide most efficiently by some mechanism other than direct hydrolysis.