Time-lapse microscopic analysis of Aureobasidium spp. growth and insights into environmental adaptation

The study of microorganisms, particularly fungi, at the microscopic level has gained increasing interest and
importance in recent years. Fungal populations and structures, such as biofi lms, have become subjects of
investigation. Fungi initiate growth from spores, extending apical hyphae to form an interconnected, treelike mycelial network. This corded network exhibits species-specifi c variations and undergoes continuous
reconfi guration in response to environmental stimuli, involving new growth, branching, fusion, or regression.
Innovative methodologies, including time-lapse microscopic observation, have provided comprehensive
visualization and quantitative analysis of morphological features, characterisation of mycelial network
dynamics, and their response to environmental changes. The integration of time-lapse microscopic observation
with mathematical analysis off ers valuable insights into simulating the growth of mycelia, which is crucial for our understanding and controlling of fungal biofi lm development, that can be implemented in various applications. In this study, we focused on visualizing the growth of Aureobasidium spp. and evaluating their morphological characteristics to generate statistical functions for simulating free mycelium growth. Cultures of A. pullulans and A. melanogenum were observed using the EVOS™ M7000 Imaging System, which captured 3D and 2D projection images at defi ned time intervals. The acquired images served as quantitative data for analysing various morphological and growth parameters of Aureobasidium spp., such as tip growth rate, hyphal density, branch angle, and branching location. Subsequently, we investigated the eff ects of nutrient, temperature, and humidity variations on fungal growth. Moreover, the relationship between A. pullulans and A. melanogenum was evaluated, as they are known to frequently colonize various building materials.