General Properties of Biotin Uptake System in Lipomyces Starkeyi

Development of a new chemically defined sporulation medium for the yeasts in the genus Lipomyces.

“…These results and prediction lead to the hypothesis that a gradual change in medium pH to the alkaline side may be an important factor to induce sporulation in L. starkeyi. A minimal glucose-mineral medium (a modified chemically defined medium proposed by Wickerham) has long been used as a standard medium for growth studies of L. starkeyi (Uzuka et al, 1975). The minimal medium has an initial pH of 5.3 and medium pH gradually decreases with cell growth.…”

Properties of the Biotin Transport System in Bifidobacterium breve N4

“…I t has been reported that Lactobacillus plantarum (18,19), Escherichia coli (11), and Lipomyces starkeyi (17) actively transport biotin until the intracellular biotin concentration reaches a plateau, but that active uptake of biotin in Saccharo-myces ceretnstae (1, 12, 13) is followed by biotin release from the cells. Such overshoot phenomena have been reported for several other transport substrates, and their mechanisms have been explained or speculated on in a few cases, as follows: active transport of sulfate in Salmonella typhimurium (3) is feedback-inhibited by a high-energy compound which is formed in the course of transport, and the rate of sulfate release is proportional to the intracellular sulfate concentration; biotin in S. cerevisiae (1) is rleased by a carrier-mediated and energy-independent process; pyridoxine transport in Saccharomyces carlsbergensis (14) is not inhibited by accumulated pyridoxine, but release of pyridoxine is accelerated by a high concentration of intracellular pyridoxine; E. coli K-12 (16) transports pyridoxine and release its metabolites (pyridoxal, pyridoxal phosphate, pyridoxamine phosphate, etc.)…”