M. A. Qadeer
Government College University
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Featured researches published by M. A. Qadeer.
Bioresource Technology | 2003
Ikram-ul-Haq; Hamad Ashraf; Javed Iqbal; M. A. Qadeer
The present study is concerned with the selection of new medium for the production of alpha amylase by Bacillus licheniformis. Different agricultural by-products such as wheat bran, sunflower meal, cotton seed meal, soybean meal, rice husk or rice bran were tested for the production of alpha amylase. Among different agricultural by-products evaluated, wheat bran was found to be the best basal and standardized medium for optimal production of alpha amylase. The production was increased 2-folds when soluble starch was replaced with pearl millet starch at 1% level and nutrient broth concentrations was reduced from 1% level to 0.5%. The newly selected fermentation medium containing (% w/v) wheat bran 1.25, nutrient broth 0.5, pearl millet starch 1.0, lactose 0.5, NaCl 0.5, CaCl2 0.2 in 100 ml of phosphate buffer. The kinetic values of Y(p/x), Y(p/s), and Q(p) indicated that the production of enzyme was greater in newly selected medium than the conventional more expensive medium.
World Journal of Microbiology & Biotechnology | 2001
Ikram-ul-Haq; Samina Khurshid; Sikander Ali; Hamad Ashraf; M. A. Qadeer; M. Ibrahim Rajoka
Spore suspensions of Aspergillus niger GCB 75, which produced 31.1 g/l citric acid from 15% sugars in molasses, were subjected to u.v.-induced mutagenesis. Among three variants, GCM 45 was found to be the best citric acid producer and was further improved by chemical mutagenesis using NTG. Out of 3 deoxy-D-glucose-resistant variants, GCM 7 was selected as the best mutant which produced 86.1 ± 1.5 g/l citric acid after 168 h of fermentation of potassium ferricyanide + H2SO4-pretreated black strap molasses (containing 150 g sugars/l) in Vogels medium. On the basis of comparison of kinetic parameters, namely the volumetric substrate uptake rate (Qs), and specific substrate uptake rate (qs), the volumetric productivity, theoretical yield and specific product formation rate, it was observed that the mutants were faster growing organisms and had the ability to overproduce citric acid.
Bioresource Technology | 2002
Ikram-ul-Haq; Sikander Ali; M. A. Qadeer
The present investigation deals with the biosynthesis of L-DOPA by parental (GCB-6) and mutant (UV-7) strains of Aspergillus oryzae. There was a marked difference between the mycelial morphology and pellet type of parental and UV-irradiated mutant culture. The mutant strain of A. oryzae UV-6 exhibited pellet-like mycelial morphology and improved tyrosinase activity. Mould mycelium was used for biochemical conversion of L-tyrosine to L-DOPA because tyrosinase is an intracellular enzyme. The mutant was found to yield 3.72 fold higher production of L-DOPA than the parental strain. The mutant strain is stable and D-glc-resistant. The comparison of kinetic parameters was also done which showed the greater ability of the mutant to yield L-DOPA (i.e., Yp/x 40.00+/-0.01 d mg/mg with parent and 182.86+/-0.02a mg/mg in case of mutant). When cultures grown for various incubation periods, were monitored for Qp, Qs and q(p), there was significant enhancement (p < 0.0025-0.005) in these variables by the mutant strain of A. oryzae UV-7 over GCB-6 on all the rates. L-DOPA (3,4-dihydroxy phenyl L-alanine) is a drug of choice in the treatment of Parkinsons disease and myocardium following neurogenic injury.
Applied Biochemistry and Biotechnology | 2007
Ikram-ul-Haq; Hamad Ashraf; Sikander Ali; M. A. Qadeer
Three strains ofBacillus licheniformis were isolated and screened for α-amylase production by solid-state fermentation. Of these, IS-2 gave relatively higher enzyme production (32±2.3 U/[g·min]) and was selected for improvement after treatment withN-methylN-nitroN-nitroso guanidine (NG) or nitrous acid (NA) to enhance its hydrolytic potential. Among the mutant variants, NA-14 gave higher enzyme production (98±1.6 U/[g·min]), and hence, was selected for kinetic and thermal characterization. M1 as a moistening agent (pH 7.0, optimized) supported 2.65-fold improved amylolytic activity by the derepressed mutant 72 h after inoculation. The values of product yield coefficient (Yp/x=1833.3 U/g) and specific rate constant (qp=25.46 U/[g·h]) with starch were severalfold improved over those from other carbon sources and the other cultures. The purified enzyme from NA-14 was most active at 40°C; however, the activity remained almost constant up to 44°C. The NA-induced random mutagenesis substantially improved the enthalpy (ΔHD=94.5±11 kJ/mol) and entropy of activation (ΔS=−284±22 J/[mol·K]) for α-amylase activity and substrate binding for starch hydrolysis. The results of this study (117.8±5.5 U/[g·min]) revealed a concomitant improvement in the endogenous metabolism of the mutant culture for α-amylase production.
Bioresource Technology | 2005
Ikram-ul-Haq; Hamad Ashraf; M. A. Qadeer; Javed Iqbal
Journal of Biological Sciences | 2002
Ikram-ul-Haq; Shafia Rani; Hamad Ashraf; M. A. Qadeer
Bioresource Technology | 2008
Ikram ul-Haq; Sikander Ali; Aafia Aslam; M. A. Qadeer
International Journal of Biological Sciences | 2005
Ikram-ul Haq; Sikander Ali; M. A. Qadeer
Bioresource Technology | 2005
Ikram-ul-Haq; Sikander Ali; M. A. Qadeer; Javed Iqbal
Biotechnology(faisalabad) | 2003
Ikram-ul-Haq; Hamid Mukhtar; Sunila Daudi; Sikander Ali; M. A. Qadeer