Characterisation and enzymatic profiling of a halotolerant Penicillium strain

Salt adapted fungi acquire great importance economically and biotechnologically due to their ability to grow and resist to saline conditions as well as other harsh ones like ultraviolet radiations, extremes pH and temperature beside their production’s capabilities of salt-resistant metabolites like compatible solutes, biopolymers, proteins, hemolysis, antibacterial, antioxidants and enzymes. These latter display a combination of other stresses like alkaline pH, high temperature, ultraviolet radiation and organic solvents alongside the salt resistance. The currently work aims to explore the physiologic and enzymatic characteristics of a halotolerant Penicillium strain isolated from an Algerian saline soil. For this purpose Penicillium sp GS15 was isolated on PDA supplemented with 20% NaCl then subjected to morphologic and B-tubulin molecular identification to confirm its affiliation to Penicillium chrysogenum strains. The physiologic characterisation on solid media displays that P.chrysogenum GS15 presents an optimal growth at 25° C, pH 5, dark and aerobic conditions with no significance effect of agitation while on liquid medium, the salinity test showed that it is highly halotolerant microorganism because of its ability to grow between 0% and 21% NaCl (w/v) with most favourable growth at 15 %. In addition, a secreted enzyme profile was also detected with agar plate method. In fact P.chrysogenum exhibits diverse extracellular enzymes such as laccases, amylases, caseinases, tannases, esterases, and lipases while no production of pectinase, lactase, cellulase, gelatinase and albuminase is revealed. On account of the capability of P. chrysogenum GS15 to tolerate salinity and to grow on non-exigent conditions beside its ability to produce various enzymes this fungus may be an interesting organism for several industrial processes.