University of Wah

About: University of Wah is a education organization based out in Rawalpindi, Pakistan. It is known for research contribution in the topics: Per capita income & Rhizobacteria. The organization has 258 authors who have published 466 publications receiving 4719 citations.

Modulation of Secondary Metabolites: A Halotolerance Strategy of Plant Growth Promoting Rhizobacteria Against Sodium Chloride Stress.

Abstract: An experiment was conducted to evaluate the role of bacterial secondary metabolites against induced salt stress. Five bacterial strains were isolated from three different habitats: Khewra salt range, oily sludge field in Chakwal, and garden soil of Quaid-i-Azam University Islamabad, Pakistan. The 16S rRNA gene and BLAST analysis of bacterial strains showed 99% sequence similarity with Pseudomonas putida AMUPP-2 (KM435273), Lysinibacillus sphaericus OUG29GKBB (KM972671), Bacillus pumilus MB431 (KP723538) isolated from salt range, Pseudomonas fluorescens B8 (KF010368) from garden soil and Exiguobacterium aurantiacum SPD2 (KX121703) from oily sludge, respectively. Pseudomonas fluorescens produced 294.98 µg/g of proline in the M9 medium supplemented with 125 mM NaCl, but its growth rate was decreased from 1.81 to 0.37. The P. putida showed faster growth rate even than control at 125 mM NaCl. B. pumilus and L. sphaericus did not show any decline in growth rate up to 100 mM NaCl. The synthesis of new amino acids were recorded at 125 mM NaCl stress, e.g., Pro, Leu, Arg in P. fluorescens and L. sphaericus, Pro, Lys, Phe, Ala in P. putida, Lys, Ala in B. pumilus, Met, Val, and Ala in E. aurantiacum. Liquid chromatography-mass spectrometry analysis of ethyl acetate extract of P. putida and L. sphaericus demonstrated that NaCl (125mM) induced the production of 3-oxo-C12 homoserine lactone, oxosteroids, and steroid esters in addition to steroidal alkaloid lysophosphatidylcholines, antibiotics phenazine-1 carboxamide, 2,4-diacetyl phloroglucinol, carbazole, phosphatidylcholine, phosphatidyl ethanol amine, and salicylic acid as signaling compound. It was concluded that P. putida and L. sphaericus could be exploited for the production of secondary metabolites that have a wide range of implications in biotic and abiotic stresses and for the production of important pharmaceutical products.

Isolation and Characterization of L-Glutaminase producing Bacteria

Abstract: Being a significant protein L-glutaminases discovers potential applications in various divisions running from nourishment industry to restorative and cure. It is generally disseminated in microbes, actinomycetes, yeast and organisms. Glutaminase is the principal enzyme that changes glutamine to glutamate. The samples were gathered from soil of Taxila, Wah Cantt and Quetta, Pakistan for the isolation of glutaminase producing bacteria. After primary screening, subordinate screening was done which includes multiple testification such as purification, observation of morphological characters and biochemical testing of bacterial strains along with 16S rRNA sequence homology testing. Five bacterial strains were selected showing glutaminase positive test in screening, enzyme production via fermentation and enzymatic and protein assays. Taxonomical characterization of the isolates identified them as Bacillus subtilis U1, Achromobacter xylosoxidans G1, Bacillus subtilis Q2, Stenotrophomonas maltophilia U3 and Alcaligenes faecalis S3. The optimization of different effectors such as incubation time, inducers, carbon source, pH, and nitrogen source were also put under consideration. There was slight difference among incubation of bacterial culture, overall, 36 hours of incubation time was the best for glutaminase production by all the strains. Optimal pH was around 9 in Achromobacter xylosoxidans G1 and Alcaligenes faecalis S3, pH 6 in Bacillus subtilis U1, pH 8 in Stenotrophomonas maltophilia U3, pH 6-8 in Bacillus subtilis Q2. Best glutaminase production was obtained at 37°C by Bacillus subtilis U1and Bacillus subtilis Q2, 30°C for Achromobacter xylosoxidans G1, Stenotrophomonas maltophilia U3 and 25°C by Alcaligenes faecalis S3. The carbon sources put fluctuated effects on activity of enzyme in such a way that glucose was the best carbon source for Bacillus subtilis U1and Bacillus subtilis Q2, Sorbitol for Achromobacter xylosoxidans G1 and Alcaligenes faecalis S3 while xylose was the best for Stenotrophomonas maltophilia U3. Yeast extract and Trypton were among good nitrogen sources for Achromobacter xylosoxidans G1 and of Bacillus subtilis U1 respectively. Glutamine was the best inducer for Bacillus subtilis Q2, Alcaligenes faecalis S3 and Stenotrophomonas maltophilia U3, while lysine for Achromobacter xylosoxidans G1 and glycine act as good inducer in case of Bacillus subtilis U1. After implementation of optimal conditions microbial L-glutaminase production can be achieved and the bacterial isolates have a great potential for production of glutaminase enzyme and their applications.

Performance of Internal Heat generation on Viscoelastic Nanofluidic Flow past a Heated Variable Riga-Plate

Abstract: This flow configuration spotlights to study viscoelastic nanofluidic flow over a vertical Riga plate influenced by mass flux condition. Constitutive laws of motion and energy is employed to formulate the problem. The physical model governs the nonlinear PDE's with suitable boundary conditions. In order to aid computation process, the nonlinear partial differential equations are converted into the system of ordinary differential equations with the help of appropriate group of scaling transformation. Shooting technique is used to get the numerical solution of the dimensionless problem. Velocity, temperature and concentration distribution is explored for various parametric situations. The influences of main parameters are emphasized via graphically.

A robust control design approach for altitude control and trajectory tracking of a quadrotor

Abstract: Introduction. Unmanned aerial vehicles as quadcopters, twin rotors, fixed-wing crafts, and helicopters are being used in many applications these days. Control approaches applied on the quadrotor after decoupling the model or separate altitude control and trajectory tracking have been reported in the literature. A robust linear H∞ controller has been designed for both altitude control and circular trajectory tracking at the desired altitude. Problem. The ability of the quadrotor system to hover at a certain height and track any desired trajectory makes their use in many industrial applications in both military and civil applications. Once a controller has been designed, it may not be able to maintain the desired performance in practical scenarios, i.e. in presence of wind gusts. Originality. This work presents the control strategy to ensure both altitude control and trajectory tracking using a single controller. Purpose. However, there is a need for a single controller that ensures both altitude control and trajectory tracking. Novelty. This paper presents a robust H∞ control for altitude control and trajectory tracking for a six degree of freedom of unmanned aerial vehicles quadrotor. Methodology. Multi input multi output robust H∞ controller has been proposed for the quadrotor for altitude control and tracking the desired reference. For the controller validation, a simulation environment is developed in which a 3D trajectory is tracked by the proposed control methodology. Results. Simulation results depict that the controller is efficient enough to achieve the desired objective at minimal control efforts. Practical value. To verify that the proposed approach is able to ensure stability, altitude control, and trajectory tracking under practical situations, the performance of the proposed control is tested in presence of wind gusts. The ability of the controller to cater to the disturbances within fractions of seconds and maintaining both transient and steady-state performance proves the effectiveness of the controller.