Fungi inhabiting in hypersaline conditions: An insight

Abstract

Until the last decade of the last century, it was believed that the contamination of food stuff preserved with salt is the only source of the halotolerant and halophilic fungi. After this era, it got established that many hypersaline lakes, solar salterns, etc. are natural habitats of such fungi. Many phylogenetically unrelated fungi were reported to grow in salty water with more than 30% NaCl concentration. A huge diversity of fungi from all the three major groups, viz., halophilic and halotolerant, xerotolerant, and sporadic, have been isolated all over the globe. Different species of Cladosporium, Aspergillus, Penicillium, Emericella, and Eurotium are some representative types of black yeast-like melanized fungi found in hypersaline conditions. Many indigenous species like Aureobasidium pullulans, Debaryomyces hansenii, Hortaea werneckii, and Wallemia ichthyophaga have also been isolated universally from the natural hypersaline environments. D. hansenii, H. werneckii, and W. ichthyophaga have been considered as model organisms for learning eukaryotic halotolerance with Hortaea werneckii being the best studied. D. hansenii is ubiquitous fungi found in the oceans globally. W. ichthyophaga was reported in 2005 only and is most halophilic fungi described to date. For proper survival and to combat the ill effects of salinity, fungi inhabiting in hypersaline conditions employ various strategies like ion exchange, accumulation of compatible osmolytes, alterations in membrane fluidity, and many more. Their special characteristics make them a potent organism with ample biotechnological potential.