The objective of this study was to isolate and identify the asparaginase-producing bacteria, then purify and characterize the enzyme in order to investigate their properties in the future. Fifteen local bacterial isolates were isolated from various sites in the city of Baghdad, identified by conventional morphological and biochemical procedures, and confirmed using vitek 2 methods, and submitted to primary screening processes for asparaginase production. For secondary screening, eight isolates with the greatest yellow zone ability on a specific solid medium were chosen. Bacillus sp. was reported to have the highest enzyme production (7.5 U/mg proteins). After 24 hours of incubation, submerged fermentation yielded optimal conditions for the production of L-asparaginase (L-ASNase) by the chosen isolate, with medium (2) serving as the optimal medium for production and fructose serving as the optimal source of carbon. In pH 6 at 40°C, Sephadex G-150 gel filtration chromatography was used to purify the enzyme. The final purification folds were increased by 2.5 times, resulting in an enzyme yield of 93.7%. It also showed the highest purified enzyme activity and stability was at 37°C. Also it revealed the highest activity and stability at pH 7.0 and pH 8.0 respectively. Enzyme lost activity when exposed to several metallic ions at concentrations of 1, 5, and 10 mM.
Six isolates of Bacillus thuringiensis were isolated from Iraqi soil characterized as non- insecticidal and non- hemolytic parasporal inclusion proteins. Bacterial isolates were propagated on nutrient broth. Then, the parasporal inclusion proteins were extracted and processed with proteinase K and trypsin. The major protein segments produced of 64KDa were characterized and tested for cytocidal activity against human leukemic T- cells (CLL) (Chronic lymphoid leukemia). Results indicated that the treated parasporal proteins of four isolates (Bt2, Bt3, Bt4 and Bt6) showed strong cytotoxicity with no significant differences between normal lymphocytes and leukemic lymphocytes. Two isolates BtA1 and BtA5 show discriminative cytotoxicity between n
... Show MoreAbstract Twenty Bacillus isolated were obtained from different sample food and water. Bacillus B1 isolated was the highest asparaginase producer, it was identified as a strain of B. subtilis. The highest production of asparaginase was observed when mineral salt medium containing 0.3% asparagen, pH 8 and incubated at 40°c for 24 hrs. B. subtilis B1 cells were immobilized by entrapment methods (calcium alginate and agar), and by adsorption on solid surface such as sawdust and cotton. The result showed that the immobilized cells by adsorption on sawdust was the best, the immobilized cell retained 88% of asparginase activity after 48h while free cell retained 65%. Cells immobilized by adsorption on sawdust was incubated at different temperatu
... Show MoreSix isolates of A. pullulans were collected from many sources including Hibiscus sabdariffa (Roselle), old Roofs of houses and bathroom surface that referred as Ap ros1, Ap or2, 3, 4 and Ap bs5, 6 respectively, all these isolates were identified based on morphological characteristics and nutritional physiology profiles, all were able to utilize various carbon and nitrogen sources such as glucose, xylose, sucrose, maltose, ammonium sulfate, ammonium nitrate and ammonium chloride, also they showed positive test for starch and amylase, while α-cellulose, ethanol, and methanol were could not be ass
... Show MorePeroxidase is a class of oxidation-reduction reaction enzyme that is useful for accelerating many oxidative reactions that protect cells from the harmful effects of free radicals. Peroxidase is found in many common sources like plants, animals and microbes and have extensive uses in numerous industries such as industrial, medical and food processing. In this study, P. aeruginosa was harvested to utilize and study its peroxidases. P. aeruginosa was isolated from a burn patient, and the isolate was verified as P. aeruginosa using staining techniques, biochemical assay, morphological, and a sensitivity test. The gram stain and biochemical test result show rod pink gram-ne
... Show MoreSeparation of Trigonelline, the major alkaloid in fenugreek seeds, is difficult because the extract of these seeds usually contains Trigonelline, choline, mucilage, and steroidal saponins, in addition to some other substances. This study amis to isolate the quaternary ammonium alkaloid (Trigonelline) and choline from fenugreek seeds (Trigonella-foenum graecum L.) which have similar physiochemical properties by modifying of the classical method. Seeds were defatted and then extracted with methanol. The presence of alkaloids was detected by using Mayer's and Dragendorff's reagents. In this work, trigonilline was isolated with traces of choline by subsequent processes of purification using analytical and preparative TLC techniques.
... Show MoreBeta-lactamase was purified from local isolate Klebsiella pneumonia by several steps included precipitation with ammonium sulphate at 20-40% saturation, DEAE- ion exchange chromatography and gel filtration on Sephacryl S-200 column. The obtained purification fold and recovery were 32.66; 47.04% respectively. The characterization of the purified beta-lactamase showed that the molecular weight was about 4000 daltons as determined by gel filtration.Purified enzyme had an optimal pH of 7 for activity and an optimal stability between pH 6.5-7.5, results shows that the optimal temperature appear to be 35 ? C .During storage the enzyme retained 72% at -20 ? C and retained 25% of the activity at the same period at 4 ? C.
In this work a Nd:YVO4 thin disc laser setup is designed and fabricated. The disk laser system
is designed to be compact. The laser crystal was pumped by a 808 nm diode laser. The effect of input
current and pulse frequency on the output energy at pulse operation mode, and the effect of the input
current on the output power at CW mode operation are tested. At the pulsed mode, the output energy
increased linearly with the input current and decreased with pulse frequency. The threshold current
increased with increasing pulse frequency increasing. The maximum output energy from the thin disc
laser was 0.98 μJ at 1.3 kHz frequency, with 0.49A. A minimum threshold current for CW mode of
operation. The maximum outpu
Endoglucanase produced from Aspergillus flavus was purified by several steps including precipitation with 25 % ammonium sulphate followed by Ion –exchange chromatography, the obtained specific activity was 377.35 U/ mg protein, with a yield of 51.32 % .This step was followed by gel filtration chromatography (Sepharose -6B), when a value of specific activity was 400 U/ mg protein, with a yield of 48 %. Certain properties of this purified enzyme were investigated, the optimum pH of activity was 7 and the pH of its stability was 4.5, while the temperature stability was 40 °C for 60 min. The enzyme retained 100% of its original activity after incubation at 40 °C for 60 min; the optimum temperature for enzyme activity was 40 °C.