Search or add a thesis

Advanced Search (Beta)
Home > Production and Immobilization of Microbial Lipases

Production and Immobilization of Microbial Lipases

Thesis Info

Access Option

External Link

Author

Rehman, Saima

Program

PhD

Institute

University of Agriculture

City

Faisalabad

Province

Punjab

Country

Pakistan

Thesis Completing Year

2011

Thesis Completion Status

Completed

Subject

Chemistry

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1623

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727021609

Similar


In the first step of the present study, cultural conditions were optimized for the enhanced production of lipase by Penicillium notatum and Pleurotus ostreatus. Different agricultural wastes viz., canola oilseed cake, sesame oilseed cake, linseed oil cake, cotton oilseed cake; rice bran and wheat bran were used as substrates for their potential to be used for the production of lipase under solid state fermentation conditions. Among these, the canola oil seed cake was proved to be best substrate for production of lipase under solid state fermentation conditions. Optimization of different physicochemical factors led to 2 folds and 1.6 folds enhancement in lipase production by Penicillium notatum and Pleurotus ostreatus respectively. Under these conditions the enzyme activity was observed to be 5335 U/gds and 3118 U/gds respectively. Penicillium lipase due to high activities was selected for further studies. Penicillium notatum lipase was purified to homogeneity by four step purification strategy to achieve 28.88 fold purified enzyme with 13.4% recovery and specific activity, 26779 U/mg. The molecular weight of the homogeneous lipase was 46 kDa as determined by SDS-PAGE. It was optimally active at pH 9.5 and 40°C. The Michaelis Menten constants (Km) and Vmax of lipase from Penicillium notatum for para nitrophenyl palmitate hydrolysis at optimum temperature were 3.33 mM and 232.6 m mol/mL min-1 respectively. The Penicillium notatum lipase was stable in the broad pH range from pH 6.0 to 12, with maximum stability in the range of 8.5-11.0. The enzyme show a high thermo-stability with half lives of 8.25 hrs, 3.2 hrs, 1.12 hrs and 0.58 hrs 40, 50, 60 and 70°C. The activation energy for denaturation was 81.1 kJ/mol. The enzyme activity was enhanced significantly by Ca2+. Exposure to hydrophobic environment (urea solution and organic solvents), did not affect the enzyme significantly. However when incubated with protease solution, denaturation of enzyme was observed. In the next part of study Penicillium notatum lipase was immobilize by carrier bound and carrier free technique of immobilization. Entrapment was more efficient in terms of high relative activity and immobilization efficiency as compared to cross linking. Both the immobilization techniques greatly enhanced the thermo stability of enzyme. Temperature optima for lipase activity shifted to higher temperatures as compared to the free enzyme. The reusability of immobilized enzyme was excellent in case of silicon entrapped enzyme. During this study we were able to find a mild cross linker (EG- NHS) which can replace the conventionally used glutaraldehyde with retention of higher activities. The cross linked aggregates of the enzyme have shown very good stability as compared to free enzyme. However the reusability was not very promising as compared to the entrapped enzyme.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

ذکر میرا وہ کریں منظور کیوں

ذکر میرا وہ کریں منظور کیوں
جانے وہ الفت سے ہیں معذور کیوں

پوچھتی ہے تم سے یہ میری وفا
جان کر مجھ سے ہوئے رنجور کیوں

آن بیٹھے وہ نظر کے سامنے
قبلہ و کعبہ ہو اب منظور کیوں

ہیں میسر ان کی مست آنکھیں جنھیں
وہ اٹھائیں بادہ و انگور کیوں

تم فضاؔ جب ہو مری محبوب تو
پھر میں دیکھوں حسن کیا اور حور کیوں

مسلم عائلی قوانین آرڈیننس ۱۹۶۱ء کی دفعہ ۴ (یتیم پوتے وغیرہ کی میراث) : اسلامی احکام کی روشنی میں تحقیقی جائزہ

Issues of inheritance have been thoroughly maintained in the Holy Quran and Sunnah. As per these injunctions, the principle of AL’Aqrab fal’aqrab “the closest in kin” is to be observed. According to these principles, grandchildren, even though orphaned, have no right to inherit grandfather in the presence of direct children. On the other hand, section 4 of Muslim Family Laws, 1961 grants a share to orphaned grandchildren from the inheritance of his grandfather. Whereas, as per the constitution, no law can be enacted which is repugnant to the injunctions of the Holy Quran and Sunnah, now, whether the above mentioned section is in conformity with the injunctions of the Holy Quran and Sunnah or not is to be treated properly. If not, so from which perspective, it is repugnant to the Islamic Injunctions? These questions have been analysed critically in this paper and finally it has been concluded that section 4 of Muslim Family Laws Ordinance, 1961 contrasts with the injunctions as laid down in the Holy Quran and Sunnah.

Some Classes of Generalized Convex and Related Functions

In this thesis, certain classes of analytic functions, such as κ − UK η ( λ , α ) , i k ( γ , γ , β ) , N i k ( η , ρ , β ) , R ( m , ρ ) and R λ , p ( a , b , c , A , B ) are κ − UQC η ( λ , α ) , R 1 2 k k introduced. These classes generalize the concepts of uniformly close-to-convex and quasi-convex, bounded turning, strongly close-to-convex, bounded boundary rotations and bounded radius rotations. These classes are special generalizations of convex and related functions. The techniques of convolution and differential subordination are employed to investigate certain problems such as inclusion results, radius problems, arc lengths, growth rate of coefficients and Hankel determinant problems and other several interesting properties of the above mentioned classes. Some well-known results appear as special cases from our main results.