English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

SUMMARY: Four strains of lactobacilli, isolated from the contaminant flora of English top fermentation brewers' yeasts, were found to be heterofermentative. Two strains were tentatively identified as Lactobacillus brevis. For growth, all the strains required exogenous supplies of a number of growth factors of the vitamin B complex, a pyrimidine, at least one purine and at least 14 amino acids. The ability of hypo- xanthine to substitute for both adenine and guinane in one strain of L. brevis is especially notable. L-Arginine, essential for the growth of all strains, increased the rate and final amount of growth in glucose medium of both strains of L. brevis, when it was supplied in relatively high concentration. Suspensions of the organisms con- verted arginine into ornithine, ammonia and a small amount of citrulline. Maltose, fructose and L-arabinose were better substrates for the growth of all strains than glucose, which, as major source of energy, supported little or no growth of the two unidentified strains. All the strains transformed fructose into mannitol. The rate and extent of growth of most strains on hexoses and the rate of growth of all strains on maltose were increased by the presence of acetate. Whereas the strains of L. brewis formed only little acid from glucose, all strains produced considerable amounts of volatile and non-volatile acids from L-arabinose. Certain lactic acid bacteria have long been recognized as beer spoilage organisms. However, unlike their counterparts which inhabit dairy products there have been few studies of the nutrition of these bacteria. Recently, Russell, Bhandari & Walker (1954) surveyed the vitamin requirements of 34 strains, comprising 10 species of brewery lactic acid bacteria. The present work is restricted to four strains isolated from pitching yeasts of top fermen- tation breweries, and reports on their nutritional requirements with respect to growth factors of the vitamin B complex, purines, pyrimidines, amino acids and major sources of energy, and some biochemical activities.

Nutritional Requirements and Biochemical Activities of Brewery Lactobacilli