Enhanced Production of an Extracellular Lipase by EMS and MMS-Induced Mutant Strain of Rhizopus oligosporus EM-7 using Almond Meal as a Basal Substrate
Amna Waseem, Sikander Ali* and Syeda Wajiha Khalid
Institute of Industrial Biotechnology (IIB), GC University Lahore, Pakistan
Fig. 1.
Effect of different level of substrate on lipase production by wild-type (Isl-9) and mutant strain (EM-7) of R. oligosporus. Distilled water 10 ml, time of incubation 72 h, temperature 30°C. --, Wild-type Isl-9; -Ο-, Mutant strain EM-7. Y-error bars state standard deviation (±SD 5%) among the values of three parallel replicates.
Fig. 2.
Effect of different moisture content and pH on lipase production by wild-type (Isl-9) and mutant strain (EM-7) of R. oligosporus. Almond meal 15 g, time of incubation 72 h, temperature 30°C. Y-error bars state standard deviation (±SD 5%) among the values of three parallel replicates. For symbols, see Figure 1.
Fig. 3.
Effect of moisture level on lipase production by wild-type (Isl-9) and mutant strain (EM-7) of R. oligosporus. Almond meal 15 g, moisture tris-HCl, pH 7, time of incubation 72 h, temperature 30°C. Y-error bars state standard deviation (±SD 5%) among the values of three parallel replicates. For symbols, see Figure 1.
Fig. 4.
Time of incubation for lipase production by wild-type (Isl-9) and mutant strain (EM-7) of R. oligosporus. Almond meal 15 g, moisture 12.5 ml tris-HCl, pH 7, temperature 30°C. Y-error bars state standard deviation (±SD 5%) among the values of three parallel replicates. For symbols, see Figure 1.
Fig. 5.
Kinetics of specific growth rate (µ h–1) and product yield coefficient (Yp/x g cells/g) for lipase production by wild-type (Isl-9) and mutant strain (EM-7) of R. oligosporus. Almond meal 15 g, moisture 12.5 ml tris-HCl, pH 7, time of incubation 72 h, temperature 30°C. Y-error bars state standard deviation (±SD 5%) among the values of three parallel replicates. The sum mean values in each set vary significantly at p≤0.05. For symbols, see Figure 1.
Fig. 6.
Effect of temperature on lipase production by wild-type (Isl-9) and mutant strain (EM-7) of R. oligosporus. Almond meal 15 g, moisture 12.5 ml tris-HCl, pH 7, time of incubation 72 h. Y-error bars state standard deviation (±SD 5%) among the values of three parallel replicates. The sum mean values in each set vary significantly at p≤0.05. For symbols, see Figure 1.
Fig. 7.
The molecular weight of lipase isolated from Isl-9, crude EM-7 and purified EM-7. Ladder, protein ladder; Lane 1, crude enzyme from Isl-9; Lane 2, crude enzyme from EM-7; Lane 3, partially purified enzyme from EM-7 with molecular weight 33 kDa.