engleski

Influence of growth phase and zeolite on the sphingoid bases biosythesis in waste brewer's yeast

Sphingolipids are a group of lipids which are present in all eukaryotic cells, particulary in plasma membranes. The backbones of complex sphingolipids (sphingoid bases and ceramides) are important intracellular second messengers that play a role in the regulation of cell growth, differentiation and programmed cell death. They are not essential food constituent, but recent studies point to their dietary significance, since their breakdown releases bioactive substance in the gastrointestinal tract. Increased uptake of food sphingolipids gives rise to reduced incidence of colon cancer and decreased concentration of plasma cholesterol. Due to its rich chemical composition, waste brewer's yeast is being increasingly used as additive and crude material in food procesing. Our research is focused on how growth conditions and addition of natural zeolite clinoptilolite to the growth medium influence the concentrations of the individulal sphingoid bases from the waste brewer's yeast. total sphingoid bases werw extracted according Riley et al. O- phthalaldehide derivatives of the sphingoid bases were prepared and analysed by HPLC. The results point out the following conclusions: waste brewer's yeast is a good source of sphingolipids and the predominant sphingoid bases is phytosphingosine. Growth phase has influence on the phytosphingosine concentration. The addition of zeolite to the growth medium caused an increase in the concentration of anlysed sphingoid bases.

waste brewer's yeast ; zeolite ; growth phase ; sphingoid bases

DOI: 10.1111/j.1742-4658.2006.05277.x