Arxula adeninivorans (Blastobotrys adeninivorans) - An imperfect dimorphic yeast of biotechnological potential

Abstract

The imperfect, haploid, dimorphic ascomycetous yeast Arxula -adeninivorans (syn. Blastobotrys adininivorans) exhibits some unusual properties. Being a thermo-, osmo- and salt tolerant species, it is able to assimilate and ferment many compounds as sole carbon and/or nitrogen sources. It utilises tannic acid, purines, xylose, n-alkanes and is capable of degrading starch. Due to these unusual biochemical properties A. adeninivorans can be exploited as a gene donor for the production of enzymes with attractive biotechnological characteristics. Examples of A. adenini-vorans genes that have been over-expressed include the ATAN1 gene encoding a secretory tannase, ALIP1 gene encoding a secretory lipase, the AXDH encoding xylitol dehydrogenase and the APHY encoding a secretory phosphatase with phytase activity. The thermo-, osmo- and salt tolerances, as well as differential morphology-dependent glycosylation pattern and the secretion characteristics, render A. adeninivorans attractive as host for heterologous gene expression. A transformation system has been established based on homologous and non-homologous integration of linearised DNA fragments. Successful expression examples such as the human HSA, IL6 and IFNα genes, as well as the production of functional recombinant receptors, for example, human estrogen receptor add to the attractiveness of A. adeninivorans as host for heterologous gene expression.