physiological and biochemival studies on some fungal isolates

Fifty-nine fungal species were isolated from three soil samples. The ability ofgrowth on cellulose as sole carbon source was studied. Cellulolytic isolatesrepresent 90%,87.5% and 95.6% in soil samples. The most active isolates obtainedwere used to determine (CMCase) when grown on cotton or wood. In soil sampleNo. (1), the most active fungal isolates were Aspergillus sp. (A W) and Aspergillussp. (T4) while Aspergillus sp. (T 5) was the most active isolate in soil sample No. (2).In soil sample No. (3), there were three fungal isolates showed high CMCaseactivity. The most active isolates were identified as Aspergillus candidus (A W), 3isolates of Aspergillus terreus (T2, T4 and T5) Trichoderma sp (Tri) andPenicillium purpurogenum (R). (RAPD) was used to investigate the polymorphismwithin isolates. The results showed that total number of amplified bands were (243).18S rRNA from all isolates were amplified. Purified PCR products were used insequencing reactions. Aspergillus candidus (A W) from soil No.1, Aspergillusterreus (T5) from soil No.2 and Trichoderma sp. (Tri) from soil No.3 were selectedto determine the factors affecting the CMCase production. Trichoderma sp. (Tri)was the most active isolate on wood and cotton. The obtained protein patternrevealed that, the CMCase system contains 2 protein components namely CMCase I(58 KDa) and CMCase 11 (34 KDa). The optimum specific activities of CMCase Iand 11 obtained at substrate concentration of 1 %. CMCase activities reaching theoptimum values at 50°C for both enzymes. The obtained results showed also thatthe specific activities increase with the increasing of the pH value of the reactionmixtures till reaching to their maximal values at pH 5.0 for both CMCase I and 11.CoCh was the most inhibitory ion for CMCase I while HgCh was the mostinhibitory ion for CMCase 11.