Search or add a thesis

Advanced Search (Beta)
Home > Characterizaton and Immobilization of Dextranase from Bacillus Species Using Different Synthetic and Non-Synthetic Polymers

Characterizaton and Immobilization of Dextranase from Bacillus Species Using Different Synthetic and Non-Synthetic Polymers

Thesis Info

Access Option

External Link

Author

Shahid, Faiza

Program

PhD

Institute

University of Karachi

City

Karachi

Province

Sindh

Country

Pakistan

Thesis Completing Year

2017

Thesis Completion Status

Completed

Subject

Biotechnology

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/12970/1/Complete%20Thesis.doc

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725702750

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Hydrothermal springs are renowned as ideal ecological niche for wide species of thermophilic microbes. Thermozymes of thermophiles have enticed commercial application owing to their stability against inimical industrial approaches. Current study is designed to explore hot springs of Gilgit, Pakistan for the isolation of thermophile capable of degrading complex polymer dextran. Dextranase not only plays a vital role in sugar processing industry but the enzymatic fractions of polymer are also of significant interest in cosmetics, pharmaceutical and food industries. Besides their vast commercial application, thermostable dextranase from non-toxin producing microbe is still a dilemma in food processing industry in order to develop an efficient and cost effective process. Therefore, efforts are being made to explore new source of thermostable dextranase.Bacillus megaterium KIBGE-IB31 [GenBank accession: KF241867] was identified as thermophile accountable for enhanced production of valuable extracellular dextranase under specific fermentation conditions. Strain characterization was based on phenotypic and genotypic analysis. The distinctive feature of this strain classified it as a GRAS and aerobic thermophile. Maximum production of 464.68 U ml-1 with a specific activity of 160.2 U mg-1 was achieved when 10.0 kDa dextran (15.0 g L-1) was amalgamated with various trace elements and nitrogen sources at 60°C up to 24 hours of fermentation time. Inoculum size and agitation speed also had a positive impact on maximum enzyme yield. Gradient precipitation resulted in 61% recovery of partially purified dextranase from crude sample. Whilst, steady state kinetics of dextranase exhibited high catalytic activity within 5.0 minutes at 50°C in 50 mM sodium phosphate buffer of pH: 07 with Vmaxand Km value of 5191 U ml-1 min-1 and 4.38 mg ml-1 respectively. The behavior of different metal ions revealed activating as well as inhibitory action on the catalytic performance of dextranase however, none of the metal ion was found to be essential for enzymatic reaction. Similar findings was observed with surfactant and solvents. SDS (10 mM) was found to be strong inhibitor while triton X-100 (10 mM) decreased 77% activity of dextranase. Data of stability studies proved thermophilic origin of dextranase as it showed stability against wide range of temperature and pH. Hydrolytic action of dextranase was observed by studying surface topology of dextran through scanning electron microscopy. Thin layer chromatography suggested that the hydrolytic response resulted in the formation of various isomalto-oligosaccharides and these oligosaccharides could be utilized as commercially important prebiotics. Immobilization of dextranase using different interactions with different matrices, bestowed covalent cross linking as influential contact of dextranase with matrix in contrast, to adsorption and entrapment methods. However, cross linking without any matrix that is CLEAs was proven to be an efficient immobilization protocol in terms of stability, reusability as well as reduced the cost due to absence of any matrix. Although the reaction time after immobilization remains same except in entrapment but the temperature and pH optima was shifted after covalent cross linking in both protocols. Being a thermostable biocatalyst the stability of dextranase was high at extreme temperature and pH, but was further improved after immobilization. The recycling efficiency of dextranase in the forms of CLEAs was highest (10 cycles with 67% residual activity) than that of other three immobilized form.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

97. Al-Qadr/Great Eminence

97. Al-Qadr/Great Eminence

I/We begin by the Blessed Name of Allah

The Immensely Merciful to all, The Infinitely Compassionate to everyone.

97:01
a. Indeed, WE began sending this down – The Qur’an –during the later part of the Night of Great Eminence.

97:02
a. And what will enable you to perceive the value, honor, magnificence of the Night of Great Eminence?

97:03
a. The Night of Great Eminence is better than the nights of a thousand months of worship and meditation.

97:04
a. The Angels descend in it and the Spirit - again and again - by the Command of their
Rabb - The Lord, for every matter of significance.

97:05
a. Spiritual peace of the Night prevails till the rising of the dawn.

حقوق الإنسان المدنية من خلال وثيقة المدينة: دراسة مقارنة بالمواثيق الدولية

حقوق الإنسان المدنية من خلال وثيقة المدينة: دراسة مقارنة بالمواثيق الدولية This research aims to give the reader a comprehensive view of civil human rights through a comparative study of the Charter of Medina and international conventions. The Charter of Medina designed the foundation of a multi-religious Islamic state in Medina, as it was signed to end the rancorous intertribal aggression among the opposing tribes of Banu ’Aws and Banu Khazraj in Medina and to uphold harmony and co-operation among all Medinan groups. Its major accomplishment was fetching confrontational clans together to form a community and inaugurating long term peace among them. It put an end to the predominant disorder and sheltered the life, self-determination, property and religious freedom for all people. The paper highlights the relevance and importance of civil human rights through the Charter of Medina as well as international conventions in the up-to-date worldwide civilization. The present research examines the historical document of Charter of Medina and elucidates it through examples from Quran and Sunnah as well as compares its core values with international conventions. In this regard the views of the past and contemporary scholarship are also discussed to analyze the challenges and issues of current time. In recent times the efforts and implications of civil human rights have unfolded in many different ways so it is very important for Muslims to know and to relate the Sharī’ah ruling regarding it. The research concludes that as compare to the international convections the system of justice in the Islamic Sharī’ah ensures all rights and with liabilities.

Physiological, Biochemical and Growth Response of Sunflower to Salinity and Boron

Low concentration of boron (B) is essential to plant growth and may limit the growth in excess quantity especially under saline conditions. Limited information was available regarding B toxicity on sunflower (Helianthus annuus L.) under saline conditions. The present studies were conducted to investigate the interactive effect of salinity and B toxicity. Hydroponics and pot studies were conducted at various B levels under normal and saline conditions. First, 10 sunflower genotypes were screened out against salinity in water culture (control, 60,120 and 180 mM NaCl). SF-187 and S-278 were ranked as tolerant to salinity whereas, Hysun-33 and Hysun-38 were categorized as sensitive genotypes against salinity. These genotypes were grown in hydroponics under saline and non-saline conditions and at control, 0.5 and 1.0 mM boron. Physical and chemical characteristics determined showed reduction in shoot fresh and dry weight was more in salt-sensitive genotypes (Hysun-33 and Hysun-38) than in salt tolerant genotypes (SF- 187 and S-278). Salt-tolerant genotypes accumulate less boron and Na + , while more K + in shoot than salt-sensitive genotypes. Root B and K + accumulation were decreased in saline conditions than non-saline conditions while Na + concentration in root increased in saline conditions. Result regarding relative water content (RWC) and membrane stability index (MSI) showed a reduction pattern with the increasing level of boron toxicity both under non-saline and saline conditions. Salt-tolerant genotypes showed more RWC and MSI than salt sensitive genotypes under saline conditions along with boron toxicity. Photosynthetic rate (PR) stomatal conductance (SC) and transpiration rate (TR) were also decreased with salinity and toxic levels of boron, and salt tolerant genotypes showed better response regarding PR, SC and TR than salt sensitive genotypes. Achene yield per plant decreased under saline conditions along with toxic level of boron and salt tolerant genotypes showed less % reduction than salt sensitive genotypes. Boron and potassium concentrations decreased under saline conditions, while Na + concentration increased under saline conditions (alone) and saline condition and B at 5 ppm concentration. Salt- tolerant genotypes had accumulated less Na + and B concentration and more K + concentration in shoot. Genotypes (SF-187 and S-278) were promising genotypes under saline conditions along with boron toxicity and can be directly used by farmers or may be used for the development of more salinity tolerant sunflower genotypes by the breeders.