Occurrence, hyphal growth rate, and carbon source utilization of fungi from continental Antarctica

Abstract

Reported data on the diversity and physiological capabilities of fungi inhabiting ice-free outcrops of continental Antarctica are limited. The present study aimed at investigating the occurrence of fungi on fragments of microbial mats on the lakeshore and lake water and compared it with fungal occurrence on terrestrial moss, using a culture-dependent method. Another purpose was to evaluate the responses of hyphal growth to temperature and the profiles of substrate utilization of fungal isolates under pure culture conditions. A total of 46 fungal isolates were obtained and grouped into eight taxa, with Phoma herbarum being the most frequent taxon, the occurrence of which was closely related to the nitrogen level of the substrata. The colony diameter growth rates of most fungal isolates under pure culture conditions increased linearly with temperature to reach the maximum at 20–25 °C, indicating that these fungi were mesophilic. Moreover, fungal isolates exhibited diversity and redundancy in their utilization of 71 carbon sources, having potentials to utilize an array of substrates including sugars, sugar alcohols, hexose-phosphates, amino acids, hexose acids, and carboxylic acids.