Isolation and characterization of a novel leaf-inhabiting osmo-, salt-, and alkali-tolerant Yarrowia lipolytica yeast strain

Salt-excreting leaves of Atriplex halimus plants harvested in the central N egev Highlands of Israel were screened for yeasts inhabiting their surfaces . Several aerobic, moderately salt- and alkalitolerant yeasts were isolated . One of the isolates (tentatively designated S-8) was identified as Yarrow ia lipolytica (Wick.) van der Walt and Arx, on the basis of its morphologic al, biochemical/physiological characteristics, and of quantitative chemotax onomic and molecular marker analyses. However, the strain is distinguished from the known members of the type Y. lipolytica strain by its pronounced o smo-, salt-, and pH tolerance. Cells displayed a unique capacity to grow ov er a wide pH range (from 3.5 to 11.5) with a pH optimum at 4.5 to 7.5. It i s proposed that the S-8 strain be assigned to a single Y. lipolytica specie s as its anamorpha, or as a new variety, Y. lipolytica var. alkalitolerance . The ecophysiological properties and biotechnological potentials of the ne w strain are discussed.