Lactobacillus casei C.S.F. folate activity.

Lactobacillus casei C.S.F. folate activity.

Coupling of energy to folate transport in Lactobacillus casei.

Lactobacillus casei cells can accumulate folate to an intracellular concentration in excess of 500 muM and to concentration gradients (relative to the extracellular compartment) of several thousand-fold. Maximum rates of folate transport are achieved rapidly (t(1/2) < 1 min) after the addition of glucose to energy-depleted cells and occur at intracellular adenosine 5'-triphosphate concentration...

Continuous-flow automation of the Lactobacillus casei serum folate assay.

A method is described for the continuous-flow automation of the serum folate assay using Lactobacillus casei. The total incubation period is approximately four hours. The growth response of the organism to folate is estimated by measuring the rate of reduction of 2,3,5-triphenyl tetrazolium chloride (TTC). A simple continuous culture apparatus is used to grow the inoculum. Supplementation of th...

Effects of deuterium oxide on folate metabolism in Lactobacillus casei.

Various folate coenzymes and their polyglutamyl derivatives involved in 1-carbon metabolism are modulated as a result of altered physiological states and also vary with respect to growth conditions. We studied the metabolic changes in folic acid and their conjugated polyglutamyl derivatives in Lactobacillus casei cells grown in the presence of D20. A 40% decrease in methyltetrahydrofolyl polygl...

Aseptic addition method for Lactobacillus casei assay of folate activity in human serum.

An ;aseptic addition' method is described for microbiological assay with Lactobacillis casei of folate activity in human serum. It has the following advantages over the previously reported ;standard' method. 1 The manipulations involved in the assay are halved, by deleting autoclaving of serum in buffers. 2 The use of 1 g.% ascorbate better preserves serum folates than the lower amounts of asco...