Isolation And Identification Of Wild Yeast From Xinjiang

1,This article investigated yeasts from south and north Xinjiang's fruits and soil from south Xinjiang Populus euphractica forest, using enrichment cultivate and lineation separated technology, from seven places obtained 31 yeast strains. Therein, fruits from Urumchi separated 9 yeast strains; from Turpan Thompson seedless grape separated 1 yeast strain; from Hotan green peach separated 5 yeast strains; from Shache Amti separated 3 yeast strains; from Kashi Ficus carica separated 5 yeast strains; from Luntai Populus euphractica forest soil separated 3 yeast strains; from Shaya Populus euphractica forest soil separated 5 yeast strains. Using yeast tradition morphological observation and physiology properties, amplifing ribosome DNA gene Internal transcribed spacer (ITS) and D1/D2 domain sequence, sequencing and made BLAST contrast with international nucleic acid database GenBank/EMBL/DDBJ, to classify species, at the same time, using CLUSTAL_W software blasted the closely related species, using MEGA 4.0 software to construct phylogenetic tree. The result showed that all of strains were classified to 6 genera and 10 species, 8 strains belonged to genus Pichia and Issatchenkia(25.8%), separately. 6 strains belonged to genus Cryptococcus, 5 strains belonged to genus Saccharomyces, 1 strains belonged to genus Rhodosporidium. From Populus euphractica forest soil separated 8 Pichia yeast strain, it showed that Pichia were the dominant yeast strain. Issatchenkia,Cryptococcus,Saccharomyces were the familiar yeast strain in Xinjiang.2,The physiology properties of isolation yeast strain show that, 18 strains could grow on 40℃(58%), 21 strains could grow on contain 10%NaCl culture medium(67.7%), 12 strains could grow on contain 100mg/L actidione culture medium(38.7%). Those characters interrelated with yeast to adapt bad environment, have these characters strain mostly separated from south Xinjiang, these characters showed that it related with south Xinjiang's bad environment.3,Basing on 26S rDNA D1/D2 domain sequence analysis, at the beginning of the experiment, considering strain KK18 and KK20 had the possibility of new species possibility(comparability 98%). The physiology character were made via Biolog system and made fatty acid analysis. But it a a pity, these two strains had short D1/D2 domain sequence, which were 377bp and 386bp, separately, but having longer sequences in database(>2000 bp), 5.8S ITS domain sequence not available, Biolog system and fatty acid analysis have no matching results, so there was no method to exactly classify those two strain, but they belonged to Pichia.sp..4,Strain KK25 had nacarat pigment, using acid and calefaction to destroy thalli cellularity, acetone to distill pigment, rough product was made a visible light complete wavelengh scan, and found it had low content, so, there was no farther separation and purification; because this strain in YEPD culture medium only can grow five to six days, designing experiment to tested it's activity, and found it could grow nice on contain 4%NaCl YEPD culture medium. It could grow well on contain NaCl culture medium, but dead in no NaCl culture medium, showed that strain growth and increase depend on salt. KK25 was Rhodosporidium paludigenum, one of sea antagonistic yeast, its normal growth and increase depended on salt.5,One yeast from jam of xinjiang Tacheng's plum was isolated and identified. 26S rDNA D1/D2 domain sequence for yeast strain was amplified by using primer pairs NL1/NL4, the acquired data were used to analyse sequence, and using neighbour-joining method to construct phylogenetic tree. To confirm identification, the morphological and physiological properties were also examined. The sequence analysis of 26S rDNA D1/D2 showed that strain KKS was closely related to Metschnikowia aff. fructicola D3895, with the similarity of 99.2%. In the phylogenetic tree drawn from neighbor-joining method , strain KKS and Metschnikowia aff. fructicola were in the same branch.