Folia Microbiol. 39 (5), 415-419 (1994) Based on Biochemical and Physiological Behavior, Where Is AspergUlusegyptiacus Better Placed? A.A. ZOHRI and M.A. ISMAIL Botany Depanmen~ Faculty of Science, Assiut University,Assiul, 71516Egypt Received February 1, 1994 Revised version July 7, 1994 ABSTRACT. Physiological and biochemical properties were tested in 45 isolates ofAspergillus egyptiacus (16 isolates), Erect/- celia nidulans (16) and Aspergillus versicolor (13). The three fungal species exhibited common and similar features. The big similarity between A. egyptiacus and E. nidulans was greater than between A. egyptiacus and A. versicolor. It included the inability to produce base either from sodium citrate or lactic acid media, growth at 45 ~ (thermophilicity), and production of very similar pigmentations on Aspergillus flavus and parasiticus agar.A, egyptiacus is therefore better placed in the AspergiUus nidulans - Emericella assemblage. Moubasher and Moustafa (1972) who first described Aspergillus egyptiacus placed it in the A. versicolor group. Samson and Mouchacca (1974) provided additional information on its morphology and physiology and they placed A. egyptiacus in the A. nidulans group as redefined by Raper and Fennell (1965). Also, Christensen and Raper (1978) included it in theA. nidulans group. Physiological and biochemical methods are used to resolve interferences within many fungal groups such as Terverticillate Penicillia (Frisvad 1981, 1985a, Bridge et al. 1989), Fusarium (Wasfy et al. 1987; Brayford and Bridge 1989), Phorna (Monte et al. 1991), Monascus (Hawksworth and Pitt 1983; Bridge and Hawksworth 1985) and Beauveria (Mugnai et al. 1989). We used biochemical and physiological characteristics to assess the degree of similarities and/or dissimilarities between A. egyptiacus, A. nidulellus (teleomorph: Emericella nidulans) and A. versicolor. MATERIALS AND METHODS Microorganisms. Forty-five isolates, 16 of each of Aspergillus egyptiacus MOUBASHER et MOUSTAFA, and Emericella nidulans (EIDAM) VUILL. (anamorph: Aspergillus nidulellus SAMSON et W. GAMS) and 13 ofAspergillus versicolor (VUILL.) TIRABOSCHIwere studied (Table I). These isolates were isolated in our laboratory from Egyptian soil (Abdel-Sater 1990), maize pollen grains, dust and air (Ismail 1990) and coconut (Zohri and Sabah 1993), and have been deposited at the Assiut University Culture Collection (AUCC), Botany Department, Faculty of Science, Assiut University, Assiut, Egypt. They were maintained on Czapek- Dox agar slopes (Smith and Onions 1983). Preparation ofinocula. A 7-d-old culture on Czapek agar slope was used to obtain a spore sus- pension in 0.2 % (V/V) aqueous Tween 80. Unless otherwise stated, inoculation from the spore sus- pension was done using a straight wire to give a single point inoculation. Physiological characters. Starch hydrolysis was tested as described by Bridge (1985). Urease was detected on Christensen urea agar (Seeliger 1956) and urease activity was indicated by the forma- tion of red-violet color around the point inoculation. Catalase was detected according to Wasfy et al. (1987). The ability to grow and cause a pH rise on either sodium citrate or lactic acid agar media was tested as described by Bridge (1985) but with phenol red (50 mg/L) as an indicator. Growth at 45 ~ was tested on Czapek-Dox agar. Pigment production was assessed on Aspergillus flavus and A. parasiticus agar (AFPA) (Pitt et al. 1983). Production of sterigmatocystin. Representative isolates ofA. egyptiacus (7 isolates), E. nidulans (7) and A. versicolor (5) were tested. Inoculated flasks, each containing 50 mL Czapek's liquid medium supplemented with 0.2 % yeast extract and 1% peptone, were incubated at 28 ~ for 10 d. Chloroform extracts of the fungal cultures were used for determining sterigmatocystin by thin-layer chromato- graphy on precoated silica gel plates (type 60 F254, Merck) by the method of Schroeder and Kelton (1975) as employed by EI-Kady and Abdel-Hafez (1981). A sterigmatocystin standard was used as reference.