Vitamin Be has for some time been implicated in protein metabolism. More recently a specific function of pyridoxal in the coenzome of tyrosine decarboxylase has been found (l), and the discovery of this function extended to include amino acid decarboxylases in general (2, 3). All members of the vitamin Be group (pyridoxine, pyridoxal,” pyridoxamine) are converted into this coenzyme (termed code...

Lactic acid bacteria play a pivotal role in many food fermentations and sometimes represent a health threat due to the ability of some strains to produce biogenic amines that accumulate in foods and cause trouble following ingestion. These strains carry specific enzymatic systems catalyzing the uptake of amino acid precursors (e.g., ornithine and lysine), the decarboxylation inside the cell, an...

When isonicotinic acid hydrazide (INH) was first used for therapy of tuberculosis many patients developed peripheral neuritis resembling that of pyridoxine deficiency. Such patients exhibited increased urinary excretion of pyridoxine; administration of pyridoxine prevented the neuritis (1). In vitro studies have confirmed that INH inhibits pyridoxinedependent bacterial decarboxylases and transa...

gamma-Aminobutyric acid (GABA) is the most widely distributed known inhibitory neurotransmitter in the vertebrate brain. GABA also serves regulatory and trophic roles in several other organs, including the pancreas. The brain contains two forms of the GABA synthetic enzyme glutamate decarboxylase (GAD), which differ in molecular size, amino acid sequence, antigenicity, cellular and subcellular ...

Many strains of a wide variety of bacterial species have been studied for their amino acid decarboxylase activity (Gale, 1946). However, to our knowledge the lactobacilli have not been examined. It has been shown in our laboratory that oral lactobacilli may be classified into three types according to their ability to attack certain carbohydrates, intensity of acid production from glucose, and b...