Durán Paola, Barra Patricio J, Jorquera Milko A, Viscardi Sharon, Fernandez Camila, Paz Cristian, Mora María de la Luz, Bol Roland
Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Temuco, Chile.
Biocontrol Research Laboratory, Universidad de La Frontera, Temuco, Chile.
Front Bioeng Biotechnol. 2019 Mar 7;7:28. doi: 10.3389/fbioe.2019.00028. eCollection 2019.
The presence of fungi in pristine Antarctic soils is of particular interest because of the diversity of this microbial group. However, the extreme conditions that coexist in Antarctica produce a strong selective pressure that could lead to the evolution of novel mechanisms for stress tolerance by indigenous microorganisms. For this reason, in recent years, research on cold-adapted microorganisms has increased, driven by their potential value for applications in biotechnology. Cold-adapted fungi, in particular, have become important sources for the discovery of novel bioactive secondary metabolites and enzymes. In this study, we studied the fungal community structure of 12 soil samples from Antarctic sites, including King George Island (including Collins Glacier), Deception Island and Robert Island. Culturable fungi were isolated and described according to their morphological and phenotypical characteristics, and the richness index was compared with soil chemical properties to describe the fungal community and associated environmental parameters. We isolated 54 fungal strains belonging to the following 19 genera: and an uncultured Zygomycete. The isolated fungi were comprised of 70% Ascomycota, 10% Zygomycota, 10% Basidiomycota, 5% Deuteromycota and 5% Mucoromycota, highlighting that most strains were associated with similar genera grown in cold environments. Among the culturable strains, 55% were psychrotrophic and 45% were psychrophilic, and most were Ascomycetes occurring in their teleomorph forms. Soils from the Collins Glacier showed less species richness and greater species dominance compared with the rest of the sites, whereas samples 4, 7, and 10 (from Fildes Bay, Coppermine Peninsula and Arctowski Station, respectively) showed greater species richness and less species dominance. Species richness was related to the C/N ratio, whereas species dominance was inversely related to C and N content. Thus, the structure of the fungal community was mainly related to soil chemical parameters more than sample location and altitude.
由于这一微生物群体的多样性，原始南极土壤中真菌的存在尤其引人关注。然而，南极洲共存的极端条件产生了强大的选择压力，这可能导致本土微生物进化出新型的抗逆机制。因此，近年来，受其在生物技术应用中的潜在价值驱动，对冷适应微生物的研究有所增加。特别是冷适应真菌，已成为发现新型生物活性次生代谢产物和酶的重要来源。在本研究中，我们研究了来自南极地区12个土壤样本的真菌群落结构，这些地区包括乔治王岛（包括柯林斯冰川）、欺骗岛和罗伯特岛。根据其形态和表型特征分离并描述了可培养真菌，并将丰富度指数与土壤化学性质进行比较，以描述真菌群落及相关环境参数。我们分离出54株真菌菌株，分属于以下19个属：以及一种未培养的接合菌。分离出的真菌中，子囊菌门占70%，接合菌门占10%，担子菌门占10%，半知菌类占5%，毛霉门占5%，这表明大多数菌株与在寒冷环境中生长的相似属有关。在可培养菌株中，55%为嗜冷菌，45%为嗜冷菌，且大多数是以有性态形式出现的子囊菌。与其他地点相比，柯林斯冰川的土壤物种丰富度较低，物种优势度较高，而样本4、7和10（分别来自菲尔德斯湾、铜矿半岛和阿克托夫斯基站）的物种丰富度较高，物种优势度较低。物种丰富度与碳氮比有关，而物种优势度与碳和氮含量呈负相关。因此，真菌群落结构主要与土壤化学参数有关，而不是与样本位置和海拔有关。
