Suchergebnisse

The present study was conducted to determine the optimum conditions required for lipase enzyme activity extracted from germinated sunflower seeds, including temperature, pH, agitation, time of incubation, enzyme concentration, substrate type, and concentrations of mineral salts and EDTA. Optimum pH, temperature and time of incubation required for lipase stability were also determined. The results showede optimum lipase activity (3.251U/ml) wasund at 30 ÌŠC and pH 7 after 20 minutes of incubation when using 1 ml lipase enzyme with 0.02 ml of CaCl2 (10 mM) at 100 rpm of agitation and in the presence of olive oil as the substrate for enzyme reaction. EDTA appeared to have inhibitory effects, while Ca+2 and Mg+2 have stimulatory effects on lipase activity. The values of lipase activity, total activity, and specific activity measured under optimum conditions were increased by 36.99%, 36.95%, and 38.21% over control, respectively. The enzyme showed stability at a temperature ranged between 30 to 50 ËšC, pH between 7 to 8, and time of incubation between 10 to 40 minutes. These results suggest that lipase enzyme extracted from germinated sunflower seeds have stability that depends on pH, temperature, and incubation period, which enables it to be used in different industries.

Lipase enzyme has attracted a lot of attention in recent years because of its diverse biotechnological applications. The present study was conducted to screen germinated seeds of four crops, namely sunflower (Helianthus annuus), flaxor linseed (Linum usitatissimum ), peanut (Arachis hypogaea ) and castor bean (Ricinus communis), for the activity of their lipases. to the study also included the extraction and purification of lipase from the seeds of the most promising crop using different solvents.
The results indicated that the maximum enzymatic activity (0.669 U/ml) was obtained when 0.1 M Tris-HCl buffer extract was used after 3 days of seed germination of all the tested species, as compared to the other test solvents (acetone and water). Sunflower germinated seeds showed the highest lipase activity, which was higher by 159.67, 185.32, and 285.90 % over the activities of castor bean, flax, and peanut seeds, respectively. Among the used ranges of saturation of ammonium sulfate, the ratio of 70% was the best in precipitating the crude enzyme, showing a highest specific activity of 2.576 U/ mg protein.
The first stage of gel filtration chromatography column by Sephadex G-200 indicated the presence of two non-identical peaks, one for protein and another for lipase activity, between the fractions of 18 to 23. The active fractions were pooled and loaded again in the Sephadex G-200 column and the eluted fractions showed two identical peaks, one for protein and another for lipase activity, between the fractions of 19 to 23. The final purification step by gel filtration showed a specific activity of 6.482 U/mg proteins with a yield of 38.75 % and 11.33 folds of time of purification. The study revealed that sunflower seeds are a better source of lipase as compared to the other used plant seeds, which can be used in different industries.

This study develops and validates a model that evaluates the effect of trust on individual monetary donations to charitable organizations (COs). Data were collected in Saudi Arabia using a two-stage approach and were analyzed via structural equation modeling. Data on psychosocial variables were collected in the first stage, and data on behavior were collected in the second stage, 4 weeks later. The findings confirm the study's novel multidimensional perspective of trust in the context of individual monetary donations to COs in Saudi Arabia. The results validate the view that trust is present only when the individuals concerned are disposed to trust others and when they believe that the COs can conduct their charitable mission, are honest in the use of their donations, and prioritize beneficiaries' rights. Individuals' trust in COs affects both the intention to donate and future monetary donation behavior.

The main purpose of this study is to determine the effect of blended teaching method on junior secondary school students' retention in Basic Technology subject in Biu Educational Zone of Borno State, Nigeria. Two research questions and two null hypotheses were formulated to guide the study. The study adopted quasi-experimental design of pretest, posttest nonrandomized nonequivalent control group design. The population of the study was 22,968 Junior Secondary School students offering Basic Technology in Biu Educational Zone of Borno State. Purposive sampling technique was used to select two Junior Secondary School in Biu Educational Zone of Borno State for the study. The total sample size was 182 students in their JSS II. The instrument for data collection was developed by the researcher titled: "Basic Technology Retention Test (BTRT)". The instrument was validated by three experts. A reliability coefficient of 0.88 was obtained using Cronchbach Alpha after the draft instrument was trial tested on 30 JSS II students of Government Day Juniour Secondary School, Damaturu, Yobe State, Nigeria. Mean and standard deviation was used to answer the research questions while z-test and ANOVA was used to test the null hypotheses at 0.05 level of significance. The finding of the study revealed that the There is significant difference in the mean retention scores of students in Basic Technology taught using blended and lecture teaching method in Biu Educational Zone of Borno State; Male students' retention mean scores were higher than their female counterpart in both blended and lecture teaching methods. This indicates that blended teaching method is effective in teaching both male and female students. Based on the findings, the following recommendations were made: Government should liaise with the appropriate school authorities in order to encourage and support the use of blended learning platform in secondary schools as this could enhance students' retention in various subjects.