Certain halophilic fungi, bacteria and archaea can grow at the highest concentrations of kosmotropic salts (possessing the ability to stabilize macromolecules; NaCl, KCl and MgSO4) and also at the highest concentrations of chaotropic salts (NaBr, MgCl2 and CaCl2) ever recorded. Chaotropic salts (destabilizing macromolecules) are more limiting for microbial growth than kosmotropic salts. Our study revealed the outstanding tolerance of several fungi to high concentrations of MgCl2 or CaCl2 without compensating kosmotropic salts. Amongst them were Aureobasidum melanogenum, Exophiala dermatitidis, Rhodototorula mucilaginosa and Candida parapsilosis, all members of the consistent dishwasher mycobiota world wide. Our study expanded the knowledge of possible active life by a diverse set of fungi in biologically detrimental chaotropic environments.
COBISS.SI-ID: 28276007
We performed the screening for biological activities of organic extracts from seven strains that represent four varieties of the black yeast Aureobasidium pullulans, that is A.pullulans var. melanogenum, A. pullulans var. pullulans, A. pullulans var. subglaciale and A. pullulans var. namibiae. Amongst them variety melanogenum consistentently inhbits dishwashers. The selected strains were monitored for haemolysis, cytotoxicity, antioxidant capacity and growth inhibition against three bacterial species. All varieties showed a strong haemolytic activity. Short-term exposure of cell lines to haemolytically active organic extracts resulted in some cases in more than 95% cytotoxicity. This finding has particular importance in light of the pathogenic potential of the dishwashers' inhabiting fungi.
COBISS.SI-ID: 3066191
Aureobasidium pullulans is a black-yeast-like fungus used for production of the polysaccharide pullulan, the antimycotic aureobasidin A, and as a biocontrol agent in agriculture. It can cause opportunistic human infections, and it inhabits various extreme environments. To promote the understanding of these traits, we performed de-novo genome sequencing of the four varieties of A. pullulans. The sequencing revealed that the differences between these four varieties of A. pullulans are large enough to justify their redefinition as separate species: A. pullulans, A. melanogenum, A. subglaciale and A. namibiae. Amongst them only A. melanogenum has a pathogenic potential. It is also the only species of the genus Aureobasidum that we isolated both from tap water and dishwashers,
COBISS.SI-ID: 3173711