Expression and characterization of a lipase EstA from Bacillus subtilis KM-BS for application in bio-hydrolysis of waste cooking oil.

A lipase EstA from Bacillus subtilis KM-BS was expressed in Escherichia coli BL21 (DE3) cells. The recombinant enzyme achieved high activity (49.67 U/mL) with protein concentration of 1.29 mg/mL under optimal conditions at the large-scale expression of 6 h and post-induction time at 30 °C using 0.1 mM isopropyl-ß-d-thiogalactopyranoside (IPTG). The optimal temperature and pH of the purified enzyme were at 45-55 °C and pH 8.0 - 9.0, respectively. Activity of the purified enzyme was stable in the presence of 1 mM Ca2+; stimulated by 1 mM Mg2+ and Mn2+, and inhibited by Fe3+. A significant amount of fatty acids was released during the hydrolysis of waste cooking oil under the catalysis of purified lipase, indicating that this recombinant lipase showed promise as a suitable candidate in industrial fields, particularly in biodiesel and detergent sector.

'R' you ready to save time? Using R to facilitate question creation in a pharmaceutical calculations course.

BACKGROUND AND PURPOSE: Pharmacists are expected to perform quick and accurate calculations throughout their careers. To achieve a proficient skill level, student pharmacists need ample and varied opportunities to practice pharmaceutical calculations. However, the creation of practice modalities can be time-consuming and labor-intensive for instructors. EDUCATIONAL ACTIVITY AND SETTING: We used the statistical analysis programming language R to create an efficient method to generate multiple variations of existing calculation questions. The method was evaluated with a group of student pharmacists as part of an 11-week calculations course. FINDINGS: This process can be challenging to set up initially. The method was able to generate over 100 variations of each calculation question. The student pharmacists who participated in the pilot study found the method to be easy to use and helpful for practicing pharmaceutical calculations. SUMMARY: We have developed an efficient method to generate multiple variations of existing calculation questions. This method can be used to create practice modalities that are more varied and challenging, which can help student pharmacists develop the skills they need to perform accurate calculations in their future careers.

Artificial neural network modeling for Congo red adsorption on microwave-synthesized akaganeite nanoparticles: optimization, kinetics, mechanism, and thermodynamics.

This work aims to synthesize akaganeite nanoparticles (AKNPs) by using microwave and use them to adsorb Congo red dye (CR) from the aqueous solution. The AKNPs with an average particle size of about 50 nm in width and 100 nm in length could be fabricated in 20 min. The effects of pH, CR initial concentration, adsorption time, and adsorbent dosage on the adsorption process were investigated and the artificial neural network (ANN) was used to analyze the adsorption data. The various ANN structures were examined in training the data to find the optimal model. The structure with training function, TRAINLM; adaptation learning function, LARNGDM; transfer function, LOGSIG (in hidden layer) and PURELIN (in output layer); and 10 neutrons in hidden layer having the highest correlation (R2 = 0.996) and the lowest MSE (4.405) is the optimal ANN structure. The consistency between the experimental data and the data predicted by the ANN model showed that the behavior of the adsorption process of CR onto AKNPs under different conditions can be estimated by the ANN model. The adsorption kinetics was studied by fitting the data into pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The results showed that the adsorption kinetics obeyed the pseudo-second-order model and governed by several steps. The adsorption isotherms at the different temperatures were studied by fitting the data to Langmuir, Freundlich, and Temkin isotherm models. The R2 obtained from the Langmuir model was above 0.9 and the highest value in three of four temperatures, suggesting that the adsorption isotherms were the best fit to the Langmuir model and the maximum adsorption capacity was estimated to be more than 150 mg/g. Thermodynamic studies suggested that the adsorption of CR onto AKNPs was a spontaneous and endothermic process and physicochemical adsorption. The obtained results indicated the potential application of microwave-synthesize AKNPs for removing organic dyes from aqueous solutions.