Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana, Slovenia.
Stud Mycol. 2008;61:21-38. doi: 10.3114/sim.2008.61.02.
Using media with low water activity, a large numbers of aureobasidium-like black yeasts were isolated from glacial and subglacial ice of three polythermal glaciers from the coastal Arctic environment of Kongsfjorden (Svalbard, Spitsbergen), as well as from adjacent sea water, sea ice and glacial meltwaters. To characterise the genetic variability of Aureobasidium pullulans strains originating from the Arctic and strains originating pan-globally, a multilocus molecular analysis was performed, through rDNA (internal transcribed spacers, partial 28 S rDNA), and partial introns and exons of genes encoding beta-tubulin (TUB), translation elongation factor (EF1alpha) and elongase (ELO). Two globally ubiquitous varieties were distinguished: var. pullulans, occurring particularly in slightly osmotic substrates and in the phyllosphere; and var. melanogenum, mainly isolated from watery habitats. Both varieties were commonly isolated from the sampled Arctic habitats. However, some aureobasidium-like strains from subglacial ice from three different glaciers in Kongsfjorden (Svalbard, Spitsbergen), appeared to represent a new variety of A. pullulans. A strain from dolomitic marble in Namibia was found to belong to yet another variety. No molecular support has as yet been found for the previously described var. aubasidani. A partial elongase-encoding gene was successfully used as a phylogenetic marker at the (infra-)specific level.
使用低水活度的介质,从来自斯瓦尔巴群岛科孚湾(Kongsfjorden)沿海北极环境的三个多温热冰川的冰川和冰下冰以及相邻的海水、海冰和冰川融水中分离出大量类芽枝霉属黑酵母。为了表征来自北极的出芽短梗霉菌株和全球范围内的菌株的遗传变异性,进行了多点分子分析,通过 rDNA(内部转录间隔区,部分 28S rDNA)以及编码β-微管蛋白(TUB)、翻译延伸因子(EF1alpha)和延伸酶(ELO)的部分内含子和外显子。区分出两种全球普遍存在的变种:var. pullulans,主要存在于略微渗透的基质和叶际中;和 var. melanogenum,主要从水生栖息地中分离出来。这两种变种都通常从采样的北极栖息地中分离出来。然而,来自斯瓦尔巴群岛科孚湾三个不同冰川的冰下冰中的一些类芽枝霉属菌株似乎代表了出芽短梗霉的一个新变种。纳米比亚白云石大理石中的一株菌被发现属于另一个变种。先前描述的 var. aubasidani 尚未得到分子支持。部分延伸酶编码基因成功地用作(种内)特定水平的系统发育标记。