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Studies on the Biosynthesis of Amyloglucosidase by Aspergillus Niger

Thesis Info

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Author

Malik, Shazia

Program

PhD

Institute

Government College University

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2009

Thesis Completion Status

Completed

Subject

Botany

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1470

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727324361

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The present study is concerned with the selection of a potent strain of Aspergillus niger and optimization of the cultural conditions for the biosynthesis of amyloglucosidase. About 150 strains of A. niger were isolated from soils of different habitats. Isolate No. 52 producing enzyme 7.46 U/ml/min was selected and assigned the name BT. The cultural conditions were optimized for the enzyme production. Five culture media were tested for maximum amyloglucosidase production in 250 ml shake flask. The culture medium M2 containing (g/l) Raw starch 10.0, lactose 10.0, (NH4)2SO4 5.0, MgSO4.H2O 2.0, CaCl2.H2O 2.0, KH2PO4 1.50, K2HPO4 0.1, Distilled water to make final volume 1000ml (pH 5.5) was found to be the best medium for the maximum amyloglucosidase production (11.05 U/ml/min). 50 ml/250ml flask was found to be optimum volume of the medium and the enzyme production was increased to 11.90 U/ml/min. Optimum temperature was 300C as the production of the enzyme following the growth of the organism was found to be maximum (12.18 U/ml/min). The production of the enzyme was optimum (13.28 U/ml/min) after 72 h of incubation, with the initial pH of the medium 5.0. 2% Starch with 1% glucose as an additional carbon source gave maximum amyloglucosidase production (14.21 U/ml/min). Addition of 0.3% ammonium sulphate in the fermentation medium increased the enzyme production (14.68 U/ml/min). While 2% spore inoculum showed best amyloglucosidase production (14.47 U/ml/min). The strain was improved by the alternate treatment of the parent strain with ethidium bromide and EMS. The mutant strain M4 120 produced an increased amount of amyloglucosidase (18.84 U/ml/min). The cultural conditions, were also optimized for mutant strain of Aspergillus niger M4 120 to obtain maximum enzyme production. The culture medium M2 produced maximum enzyme (19.49 U/ml/min). With 50 ml volume of the fermentation medium, amyloglucosidase production increased (20.32 U/ml/min). The temperature, 300C was optimum and enzyme production was maximum at this temperature (20.30 U/ml/min). After 72 h of incubation amyloglucosidase reached its maximum level (20.46 U/ml/min). The initial pH 5.0 was found to be best with the enzyme production (21.86 U/ml/min). Starch was the best carbon source and at 2% starch concentration the productivity of the enzyme increased to 22.84 U/ml/min. When 1% glucose was added as the additional carbon source along with starch still an increased amount of enzyme production was obtained (24.13 U/ml/min). Different nitrogen sources of organic and inorganic nature were tested for the enzyme production. Ammonium sulphate was found to be the best nitrogen source. The enzyme production increased with the addition of ammonium sulphate to 24.16 U/ml/min of amyloglucosidase. When 0.4% concentration of ammonium sulphate was added to the fermentation medium the enzyme production increased to its maximum level (25.29 U/ml/min). Spore inoculum was found better as compared to the vegetative inoculum. With 2% spore inoculum maximum amyloglucosidase production was achieved. Scale-up studies were carried out in a stirred fermentor of 7.5 litres capacity. The production of the amyloglucosidase was maximum when the volume of the medium was 60% (4.5 litres), the speed of agitation was 200 rpm and the aeration rate was maintained at 1.0 l l-1min-1 exhibiting 25.15 U/ml/min of amyloglucosidase. When 4% inoculum was added the maximum enzyme production (25.28 U/ml/min) was achieved after 48 h. The optimum initial pH of the medium was found to be 5.0. After the optimization of the cultural conditions in the stirred fermentor, partial purification of amyloglucosidase was performed by ammoniun sulphate precipitation. The enzyme activity was more in the range of 40-70 % saturation level. The specific activity of amyloglucosidase increased after the partial purification and the maximum specific activity was achieved at 70% ammonium sulphate saturation (21000 U/ml/min). Sodium dodecylsulphate polyacrylamide gel electrophoresis was run to determine the molecular weight of amyloglucosidase. The molecular weight of partially purified amyloglucosidase was found to be 65 KDa approximately. The characterization of the enzyme was done. The optimum amyloglucosidase activity was obtained at pH 4.75, 600C after 60 min at 5% starch concentration
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قائد کا فرمان کام، کام اورکام

قائد کا فرمان کام ، کام اور کام
نحمدہ وَ نُصَلِّیْ علی رسولہ الکریم امّا بعد فاعوذ بااللہ من الشیطن الرجیم
بسم اللہ الرحمن الرحیم
معزز اساتذہ کرام اور میرے ہم مکتب ساتھیو!
آج مجھے جس موضوع پر اظہار خیال کرنا ہے وہ ہے:’’قائد کا فرمان کام، کام اور کام‘‘
جنابِ صدر!
اس کا ئناتِ رنگ و بو میں جو رنگینیاں نظر آرہی ہیں، اس کائنات میں جوحسن نظر آرہا ہے اس کائناتِ رنگ و بو میں جو تنوع دکھائی دے رہا ہے، اس کائنات کے گلشن میں جو بہار آ ئی ہوئی ہے، یہ سب کچھ اپنے آپ وجود میں نہیں آگیا، یہ کسی نہ کسی کاریگر کا شاہکار ہے، کسی نہ کسی محنتی کی محنت ہے۔
جنابِ صدر!
محنت اور جدوجہد ہی انسان کو انسانیت کے مقام پر فائز کرتی ہے، معاشرے میں اس کا ایک مقام بناتی ہے، کام سے محبت ہی بڑے بڑے کا م بناتی ہے، کام کرنے والا شخص کسی کا دست نگر نہیں ہوتا، اُس کی خودی میں اضافہ ہوتا ہے، اُس کی خودداری کی دیوار میں شگاف نہیں پڑتا، وہ غریب اور بے کس کی دستگیری بھی کر سکتا ہے۔
بے محنت پیہم کوئی جوہر نہیں کُھلتا
روشن شرر تیشہ سے ہے خانۂ فرہاد
صدرِذی وقار!
بانیٔ پاکستان قائدِ اعظم محمد علی جناح رحمۃ اللہ علیہ کا یہ فرمان زبان زدعام ہے کہ کام ، کام اور کام، اس نابغۂ روزگارہستی نے کام کر کے یہ ثابت کر دیا کہ اگر انسان کا ارادہ نیک ہو، انسان کے جذبات حق وصداقت کے ترجمان ہوں، اور مقصد نیک ہو، عوام النّاس کی خدمت کا جذبہ موجزن ہو تو مقصد کے حصول میں کوئی چیز رکاوٹ پیدا نہیں کرسکتی۔
صدرِذی وقار!
قائدِاعظم محمد علی جناح رحمۃ اللہ علیہ نے جب یہ فرمایا، کہ کام سے تعلق پیدا کرو،...

Introduction to Communication Research: The First Basic Steps

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Factors Affecting the Performance of Teachers at Higher Secondary Level in Punjab

The purpose of this study was to improve the job performance of teachers by measuring the factors affecting the performance of teachers at higher secondary level. Main objectives of the study were to measure and summarize the perceptions of principals, teachers themselves and students about the factors that influence teachers’ performance, to compare teachers’ performance on each factor in the light of perceptions of principals, teachers themselves and students, to determine the rating of principals, teachers themselves and their students on each factor, to discover the level of presence of each factor on teachers’ job performance in the light of perceptions of principals, teachers themselves and students and to recommend improvement of the existing situation. The study was descriptive in nature. All the principals, teachers and students at higher secondary level in Punjab constituted the population of the study. The principal, five teachers and ten students were included in the sample from each institution, thus the sample consisted of 1920 individuals i.e. 120 principals, 600 teachers and 1200 students. Three types of closed ended questionnaires on five point rating scale were prepared separately for principals, teachers and students. The data obtained were tabulated, analyzed and interpreted by using statistical techniques as, mean, standard deviation, average rating and analysis of variance (ANOVA). The main conclusions of the study were that the factor of subject mastery was perceived by the principals, teachers themselves and students to be at the highest level among the four factors of teachers’ job performance. The factor of attitude toward students was viewed to be at the lowest level among the four factors of teachers’ job performance. Teaching methodology and teachers’ personal characteristics were factors considered to be present in teachers’ performance at intermediary level. xiiiThe average rating of teachers was the highest whereas that of students was the lowest on all the four factors, namely the attitude toward students, subject mastery, teaching methodology and personal characteristics of teachers’ job performance. The rating of the principals was at intermediary level. There was no real difference among the views of principals, teachers themselves and students about teachers’ performance on the factors of attitude toward students, subject mastery and teaching methodology. However, the views of principals, teachers themselves and students were found different on the factor of teachers’ personal characteristics. On the basis of analysis of the study, it was recommended that though the factor of teachers’ job performance was found on the highest level in the present study, yet teachers should continue their attention and improve their command on the content through self study and by attending in service refresher courses. The attitude toward students, as a factor of teachers’ job performance as analyzed was perceived at the lowest. So teachers need to improve their approach toward the students in order to improve their performance. Teachers are required to continually improve their teaching methodology by consulting internet media, new informatory literature to bring innovation in their teaching methodology. The factor of personal characteristics of teachers’ job performance was given the third position among the four factors, thus teachers should give specific attention toward this factor by improving their personality characteristics such as use of easily understandable language, removal of potential blocks to communication, use of key vocabulary, use of different channels of communication to facilitate the students and xivalso speak clearly and vary the tone pitch and inflection of the voice to all areas of the classroom. In the light of above mentioned conclusions, it can be suggested that if teachers improve their performance on the four factors attitude toward students, subject mastery, teaching methodology and personal characteristics, a significant improvement can be made in teachers’ job performance. Due to few research studies conducted in Pakistan, there is a need to conduct more studies in this area in the future. The present study was conducted in the province of Punjab, the future researchers may expand it to other provinces of the country in order to measure the factors affecting the teachers’ job performance at national level. The present study was delimited to four factors only as attitude toward students, subject mastery, teaching methodology and personal characteristics, whereas the literature indicates a number of other factors such as the classroom environment, general mental ability, personality, relations with students, preparation and planning, effectiveness in presenting subject matters, relations with other staff, self improvement, relations with parents and community, poise, intellect, teaching techniques, interaction with students, motivational skills and fairness in grading etc.