서 론
Until now, almost all yeasts have been isolated and re- ported from Korean fermented foods and their raw ma- terials such as traditional alcohol beverages and nuruks, soy sauces and soy pastes and its koji, meju etc. [1-4].
Recently, we isolated various yeasts from wild flowers in cities [5, 6], mountains [7], and coastal areas [8], and islands including Jeju-island [9], Ulleungdo and Yokjido [10], Korea. We also screened and characterized unrecor- ded yeasts [11, 12].
In a previous paper, we reported on yeast diversities of flowers and fruits in some orchards [13] of Yesan-gun and Hanbat arboretum [14] of Daejeon city, Korea. This study describes the microbiological characteristics of the unrecorded yeasts screened from the above mentioned orchards and arboretum.
Characteristics of the unrecorded yeasts from orchard flowers of Yesan-gun, Chungcheongnam-do, Korea
We screened the unrecorded yeasts by searching Keris, PubMed and other fungal taxonomy databases [11] and investigated their morphological and cultural characteri- stics using a previously described method [11, 12].
Six unrecorded yeasts, Cryptococcus festucosus 41-3 and Cryptococcus heveanensis, 56-4, Debaryomyces nepalensis 95-4, Issatchensis occidentalis 142-1, Dioszegia zsoltii 39-1, and Kwoniella europaea 47-2 were screened from 108 yea- sts from flowers and fruits in three orchards of Yesan-gun, Korea. The morphological and cultural characteris- tics of the six unrecorded yeasts are summarized in Table 1. All of the unrecorded yeasts had various shapes, and did not form pseudomycelium, except K. europaea 47-2.
Fig. 1. Morphological characterization of six isolates of yeasts (Scale bar = 2 µm). A; Dioszegia zsoltii 39-1, B; Cryptococcus festucosus 41-3, C; Kwoniella europaea 47-2, D; Cryptococcus heveanensis 56-4, E; Debaryomyces nepalensis 95-4, F; Issatchenkia occidentalis 142-1.
Fig. 2. Morphological characterization of three isolates of yeasts (Scale bar = 2 µm). A; Cryptococcus rajasthanensis HB80-4, B; Ogataea polymorpha HB45-1, C; Rhodotorula hinnulea HB62-2.
All of the unrecorded yeasts, except D. zsoltii 39-1 grew well in yeast extract-peptone-dextrose (YPD), yeast ext- ract-malt extract (YM), and potato-dextrose (PD) broth. D. nepalensis 95-4, I. occidentalis 142-1, and K. europaea 47-2 grew in vitamin-free media. In particular, C. festu- cosus 41-3 grew well in 5%-NaCl containing YPD medi- um and was also an alkalophile, growing in the range of pH 7.0~10.0.
Bai et al. [15] first reported on a new ballistoconi- dium-forming yeast, Dioszegia zsoltii, from various plant leaves collected in Yunnan, China. Cryptococcus festucosus was also reported as a new hymenomycetous yeast in the holtermannia clade [16], and Guerreiro et al. [17] re- ported on Kwoniella europaea, basidiomyces yeast, which have a tetropolar mating system. Cryptococcus heveanensis [18] was known as a sister species to the pathogenic Cryptococcus species and Issatchenkia occidentalis [19] was first isolated from the esophagus of a leukemic pa- tient. Ethanol production of Debaryomyces nepalensis [20] was also reported. However, their taxonomic characteri- stics or application in industry have not yet been studied in detail.
Characteristics of the unrecorded yeasts from flowers in Hanbat arbotretum of Daejeon city, Korea
Ogataea polymorpha HB45-1, Rhodotorula hinnulea HB 62-2, and Cryptococcus rajasthanensis HB80-4 were scr- eened as unrecorded yeasts from 51 yeasts from flowers and fruits in Hanbat arboretum, Daejeon city, Korea. All of them were globose in shape and did not have pseudo- mycelium. Three unrecorded yeasts grew well in YPD, YM, and PD media and vitamin-free medium. C. rajasthanensis HB80-4 was sugar-tolerant, growing in 50% glucose-containing YPD medium and was also a halo-tolerant yeast with O. polymorpha HB45-1, grew in 5% NaCl-containing YPD medium.
Ogataea polymorpha is closely related to Ogataea parapolymorpha, the ascosporic state of Candida parapolymorpha [21] and Cryptococcus rajasthanesis, an anamor- phic yeast, is also related to C. laurentii, isolated from Rajasthan, India [22].
