Uptake of Zn2+ by yeast and mycelial growth form of Aureobasidium pullulans grown in chemostat culture

Abstract

The yeast-mycelial dimorphic fungus Aureobasidium pullulans was grown in chemostat culture in mineral medium under zinc-limiting and zinc-sufficient conditions. The Zn P uptake of both the yeast and mycelial growth form conformed to saturation kinetics and the Zn P uptake appeared to be energy dependent and no efflux was demonstrated. No significant difference between the K m and V mx values of the yeast and mycelial growth forms were found when grown under glucoselimiting (adequate zinc) conditions, with 7.6 WM Zn P in the feed medium. Growth conditions (zinc limitation or adequate zinc) were shown to influence the Zn P uptake capabilities as yeast cells harvested from zinc-limited chemostat culture had a higher affinity (K m = 0.13 WM) and a higher V mx (1.67 nmol Zn P min 3I (mg dry wt.) 3I ) than yeast cells harvested from zinc adequate chemostat culture (K m = 0.36 WM; V mx = 0.64 nmol Zn P min 3I (mg dry wt.) 3I ). z

Physical and Chemical Properties of Organic Mineral Additive for Ruminant Through Biologically Incorporated by Saccharomyces Cerevisiae in Diference Substrates

“…Fe 2+ , Zn 2+ , Mn 2+ , Cu 2+ Co 2+ and I -) had a chance to bind organic compound as metabolic product or entry into yeast cells. This mechanism was supported that yeast Aureobasidium pullulans had capable to uptake Zn 2+ and incorporated with mycelia cells 4 . Furthermore, S. cerevisiae supports binding system between Fe and organic compound such as amino acids, e.g.…”

“…Addition of Zn 2+ into medium supported the mycelia yeast growth. It would be associated with mineral incorporated by either cells or organic substances in the cells made chelated minerals (4) . Micromineral supplementation in organic form was improving broiler performance (5) , feed digestibility (6) , health and reproductive performance of ruminant (7) .…”