Contents lists available at ScienceDirect Process Biochemistry journal homepage: www.elsevier.com/locate/procbio Review Salt-adapted moulds and yeasts: Potentials in industrial and environmental biotechnology Haliru Musa a,b , Farizul Hafiz Kasim a,b, ⁎ , Ahmad Anas Nagoor Gunny b,c , Subash C.B. Gopinath a a School of Bioprocess Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia b Centre of Excellence for Biomass Utilization, School of Bioprocess Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia c Department of Chemical Engineering Technology, Faculty of Engineering Technology, Universiti Malaysia Perlis, 02100 Padang Besar, Perlis, Malaysia ARTICLE INFO Keywords: Hypersaline environment Halophilic Halotolerant Filamentous fungi Yeast ABSTRACT Salt-adapted fungi are well-known inhabitants of hypersaline environments such as saltern, brine, estuary, salt lake, and marine environment, characterized by a high salt tolerance. Halophilic and halotolerant fungi have evolved with various special adaptive mechanisms, enable them to survive in elevated salt conditions. In most cases, these organisms are able to adapt extreme environmental conditions of temperature, pH, and ultraviolet radiation. Due to their successful thrive in high saline condition and combination of other harsh conditions, have been considered to be a paramount in the search for novel strains with industrial and environment biotechno- logical potentials. Salt adapted fungi possess a remarkable genetic reservoir, will culminate in the development of robust industrial organisms. Thus, in this review an approach has been made to concisely elucidate the biodiversity and eco-physiology of salt-adapted/salt-tolerant yeasts and filamentous fungi, their mechanism of adaptation in the hypersaline environment, as well as their biotechnological potentials. 1. Introduction Extreme hypersaline environments have hitherto and considered being almost completely inhabited by prokaryotic organisms for several decades. Over 8 decades after the discovery of salt-adapted bacteria, fungi were recognized as xerophilic or xerotolerant [1], indicates fungi can thrive in an environment of low water activity (aw). They have usually associated food contaminants, had been accumulated with higher concentrations of sugar and salt. It was however not until about two decades ago, Gunde-Cimerman et al. [2] showed that fungi are capable of inhabiting hypersaline environments. Since then, diverse salt-tolerant fungal strains have been explored and consistently isolated from saline environments all over the world regardless of the geo- graphical location [3] and classified (Fig. 1). Salt-adapted (halophilic) or salt-tolerant (halotolerant) fungi are salt-loving organisms flour- ishing in a hypersaline environment. They comprise a heterogeneous group of organisms that need salts for the ideal growth and metabolism. They are adapted to the extreme concentrations of NaCl, extreme temperature, for example, in hydrothermal vents [4], as well as higher concentration of various ions and high ultraviolet irradiation and in some exceptions, to pH extremity (Fig. 2;[2,4]). Usually, a hypersaline environment possesses salt concentration higher than that of seawater. It can be described as thalassohaline (for example, solar saltern and salt marsh), that is derived from the evaporation of seawater or in contrast, athalassohaline (Great Salt Lake and Dead Sea), its chemical composi- tion is estimated by certain geographical, geological, and topographical parameters [5]. Hypersaline environments are broadly included saline water (sea water, brackish water, oceanic water, water from salt lakes and salterns), saline soil (salt marshes, desert salts, and salt mines) and salted food products (traditional fermented foods). Halophily fungi can be defined as the species of organisms char- acterized by the high frequency of isolation on the selective saline media from saline environments beyond 10%, and at the same time cultured in vitro on media with a minimum of 17% NaCl. Fungi with the above-described properties are considered as halophilic [6]. On the other hand, if they are isolated from the lower salinity water but nonetheless still able to survive in vitro at 17% NaCl, they are termed as halotolerant. Fungi are ubiquitous in hypersaline environment around the world and composed of meristematic melanised yeast-like fungi so-called black yeasts and several related Cladosporium species [7,8], non-mela- nized yeasts, filamentous genera, Wallemia, Alternaria, Scopulariopsis and species of the genera Aspergillus, Penicillium, as well as their tele- omorphic genera, Eurotium and Emericella. These salt-adapted fungi are https://doi.org/10.1016/j.procbio.2018.03.026 Received 12 February 2018; Received in revised form 9 March 2018; Accepted 26 March 2018 ⁎ Corresponding author at: School of Bioprocess Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia. E-mail addresses: hallyruh@gmail.com (H. Musa), farizul@unimap.edu.my (F.H. Kasim), ahmadanas@unimap.edu.my (A.A. Nagoor Gunny), subash@unimap.edu.my (S.C.B. Gopinath). Process Biochemistry xxx (xxxx) xxx–xxx 1359-5113/ © 2018 Elsevier Ltd. All rights reserved. Please cite this article as: Musa, H., Process Biochemistry (2018), https://doi.org/10.1016/j.procbio.2018.03.026