Yeast Extracellular Proteases

Abstract

Many species of yeast secrete significant amounts of protease(s). In this article, results of numerous surveys of yeast extracellular protease production have been compiled and inconsistencies in the data and limitations of the methodology have been examined. Regulation, purification, characterization, and processing of yeast extracellular proteases are reviewed. Results obtained from the sequences of cloned genes, especially the Saccharomyces cerevisiae Bar protease, the Candida albicans acid protease, and the Yarrowia lipolytica alkaline protease, have been emphasized. Biotechnological applications and the medical relevance of yeast extracellular proteases are covered. Yeast extracellular proteases have potential in beer and wine stabilization, and they probably contribute to pathogenicity of Candida spp. Yeast extracellular protease genes also provide secretion and processing signals for yeast expression systems designed for secretion of heterologous proteins. Coverage of the secretion of foreign proteases such as prochymosin, urokinase, and tissue plasminogen activator by yeast in included.

Production of alkaline protease by a genetically engineered Aspergillus oryzae U1521.

“…However, a trend on the inhibitory effect of casitone and casein in A. oryzae U1521 was noted on alkaline protease production at an increasing concentration. This might be due to nitrogen metabolite repression, reported as a regulatory on the synthesis of protease in many yeasts (Ogrydziak, 1993).…”

Biosynthesis of Industrially Relevant Extracellular Pectinase from Aspergillus terreus NCFT 4269.10 Using Orange Peels as Substrate

“…Nonetheless, pectinase is an inducible enzyme and is generally induced in the presence of carbon sources such as pectin, its hydrolytic product or maltose (Morkeberg et al, 1995). Pectinases of bacterial sources have long been employed in industries, but, they are now substituted by pectinase of fungal origin (Ogrydziak, 1993), as the extraction is comparatively easier and swiftly separated from mycelium (Phadatare et al, 1993). Both LSSF and SSF processes are usually employed for biosynthesis of enzymes though various amendments have been suggested.…”

The Expression of Secreted Aspartyl Proteinases of Candida Species in Human Whole Saliva

“…Saliva contains antimicrobial proteins including immunoglobulins, lysozyme (muramidase), lactoferrin and the peroxidase system [14]. Lactoferrin and peroxidase are likely to be degraded proteolytically in the same manner as the secreted immunoglobulins by proteinases of Candida spp., although lysozyme is resistant due to its basic iso-electric point and high charge [5]. The attenuation of C. albicans Sap production by sublethal concentrations of lysozyme (unpublished observations) indicates that the Sap activity may be modulated by salivary constituents in vivo.…”