Biodiversity in Aspergillus nidulans Group ontThe Basis of Lipases Profile

"ABSTRACT Thermophilic fungi are highly specific group of organism due to their adaptability of higher temperature and presence of thermostable proteins which contain lipids of variable lengths. In the present study various strains of Aspergillus nidulans group were diversified on the basis of their lipid degrading potency. A total of 27 strains were tested using a chromogenic lipid substrate of p-nitrophenol group attached to variable length of carbon chains for rapid detection of extracellular production of lipases at different temperatures. Almost all the test fungi showed extracellular lipase C18 activity at all higher temperature i.e., ranging between 350C to 600C temperatures. In most of the cases minimum activity of this enzyme was recorded at 350C and 600C temperatures, while its optimum activity was recorded at 450C. Different strains of the same species differ in their optimum temperature requirements for extracellular lipase C18 production. Reddy and Reddy (1983) reported increases lipase production with the age of fungal culture while studying the effect of temperature, pH and age of the cultures on lipase. Fungal strains which showed poor activity at 160C temperature includes strains of A. nidulans (TH133), Emericella nidulans (TH 6 B) after two weeks of incubation, A.nidulans (TH 2 and TH 15)and E. quadrilineata (TH 37 and TH 69) took three weeks of incubation and A.nidulans (TH 6A ,TH 21 and TH 68). E. nidulans var. echinulata (TH11) E.quadrilineata (TH 12, TH 81, TH 134 andTH135) required four weeks of incubation for the initiation of lipase C18 activity. "