Yeasts and yeast-like fungi associated with tree bark: diversity and identification of yeasts producing extracellular endoxylanases.
A total of 239 yeast strains was isolated from 52 tree bark samples of the Medaram and Srisailam forest areas of Andhra Pradesh, India. Based on analysis of D1/D2 domain sequence of 26S rRNA gene, 114 strains were identified as ascomycetous; 107 strains were identified as basidiomycetous yeasts; and 18 strains were identified as yeast-like fungi. Among the ascomycetous yeasts, 51% were identified as members of the genus Pichia, and the remaining 49% included species belonging to the genera Clavispora, Debaryomyces, Kluyveromyces, Hanseniaspora, Issatchenkia, Lodderomyces, Kodamaea, Metschnikowia, and Torulaspora. The predominant genera in the basidiomycetous yeasts were Cryptococcus (48.6%), Rhodotorula (29%), and Rhodosporidium (12.1%). The yeast-like fungi were represented by Aureobasidium pullulans (6.7%) and Lecythophora hoffmanii (0.8%). Of the 239 yeast strains tested for Xylanase, only five strains of Aureobasidium sp. produced xylanase on xylan-agar medium. Matrix-assisted laser desorption ionization-time of flight analysis and N-terminal amino-acid sequence of the xylanase of isolate YS67 showed high similarity with endo-1-4-beta-xylanase (EC 3.2.1.8) of Aureobasidium pullulans var. melanigenum.
Bhadra
Bhaskar
B
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
Rao
R Sreenivas
RS
Singh
Pavan K
PK
Sarkar
Partha K
PK
Shivaji
Sisinthy
S
D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D007194:India; D010641:Phenotype; D010802:Phylogeny; D024301:Plant Bark / Q000382:microbiology*; D012335:RNA, Ribosomal / Q000145:classification; D014990:Xylans / Q000378:metabolism; D015003:Yeasts / Q000145:classification / Q000201:enzymology* / Q000235:genetics
D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; D014990:Xylans; D043364:Endo-1,4-beta Xylanases