Isolation And Identification Of Protease Producing Bacteria From Various Sources Related To Hevea Brasiliensis

Screening and isolation of proteolytic bacteria were carried out from Hevea brasiliensis tree including from bark, fresh latex, coagulated rubber, soil around the tree, latex from processing tank, residual latex on soil and effluent from effluent treatment pond. Fifteen isolates showed hydrolysis on 10 % of skim milk agar, indicating protease production from these isolates. Among the isolates, three were identified as Bacillus sp. and were selected for further study, designated as Strain K, Strain M and Strain O. Strain K and Strain O showed growth temperatures as high as 45 ºC within a broad pH range of 4 to 10

Synthesis of Chitosan/Zinc Oxide Nanoparticles Stabilized by Chitosan via Microwave Heating

Nowadays, zinc oxide (ZnO) has attracted attention in research and development because of its remarkable antibacterial properties. Chitosan/ZnO nanoparticles were successfully synthesized via microwave heating. The objectives of this work were to investigate the effect of stabilizer, power heating and time heating on size of chitosan/ZnO nanoparticles and to determine antibacterial activity against pathogenic bacteria, where chitosan was used as a stabilizing agent. Chitosan/ZnO nanoparticles were analyzed  by Fourier Transform Infra Red (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and Zetasizer instrument. The power heating and time heating were varied from 400 to 800 Watt and 4 to 8 minutes, respectively. The presence of chitosan has role on preventing the nanoparticles from agglomeration by producing a milky solution of chitosan/ZnO nanoparticles without any suspensions. The increase of power  and time heating improved the size of nanoparticles. The peak in FTIR spectrum at around 427 cm-1 was confirmed the existence of the ZnO phase. XRD patterns showed that the chitosan/ZnO nanoparticles materials were pure phase with average crystalline size is 130 nm. FESEM revealed that chitosan/ZnO nanoparticles were uniformly distributed with the mean value of size is 70 nm and spherical shaped. Further impact of power and time heating on the size of the chitosan/ZnO nanoparticles can be shown by a nanoparticles size distribution with the average of 30 to 90 nm. The results showed that chitosan/ZnO nanoparticles have displayed an antibacterial inhibition zone against Gram-positive S. aureus and Gram-negative E. coli which 16.0 and 13.3 mm, respectively. Chitosan/ZnO nanoparticles were synthesized in this work presented have potential application to prevent bacterial infections.

Microwave-assisted Synthesis of ZnO Nanoparticles Stabilized with Gum Arabic: Effect of Microwave Irradiation Time on ZnO Nanoparticles Size and Morphology

The conventional heating methods of nanoparticle synthesis regularly depend on the energy inputs from outer heat sources that resulted high energy intake and low reaction competences. In this paper ZnO nanoparticles stabilized with gum arabic are synthesized using precipitating method assisted by simple and cost effective microwave heating technique. The objective of this work is to investigate the effect of microwave irradiation time towards ZnO nanoparticles morphology and size. The effect of microwave irradiation time has been investigated at 2, 4, 6, and 10 minutes. Dynamic Light Scattering (DLS) was employed to measure the size of ZnO nanoparticles. Ultraviolet–Visible spectroscopy (UV-vis), Fourier-Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) were used for the characterization of the ZnO nanoparticles. UV-vis absorption spectrum was found in the range of 350 nm indicating the absorption peak of ZnO nanoparticles. FTIR spectra showed peaks range from 424 to 475 cm–1 which indicating standard of Zn–O stretching. The presence of (100), (002), and (101) planes were apparent in the XRD result, indicating the crystalline phase of ZnO nanoparticles. The increase in the microwave irradiation time affected the processes of nucleation and crystal growth promoted larger ZnO nanoparticles size. Microwave irradiation time at 2 minutes was selected as the best microwave irradiation time for smallest ZnO nanoparticles averaging about 168 nm sizes based on DLS analysis. Copyright © 2019 BCREC Group. All rights reserve

Synthesis of ZnO nanoparticles with chitosan as stabilizing agent and their antibacterial properties against Gram-positive and Gram-negative bacteria

Antibacterial activity of zinc oxide (ZnO) nanoparticles have received significant interest, particularly by the implementation of nanotechnology to synthesize particles in nanometer region. ZnO nanoparticles were successfully synthesized through microwave heating by using chitosan as a stabilizing agent and characterized by UV–vis, FTIR, XRD and FESEM-EDX. The aim of the present study is to determine the antibacterial activity of ZnO nanoparticles against Gram-positive bacterium Staphylococcus aureus (S. aureus) and Gram-negative bacterium Escherichia coli (E. coli). The antibacterial effect of ZnO nanoparticles was investigated for the inhibition zone and inactivation of cell growth. The absorption of ZnO nanoparticles was found to be around 360 nm. FTIR results showed the stretching mode of ZnO nanoparticles at 475 cm−1 of the absorption band. EDX results indicated that ZnO nanoparticles have been successfully formed with an atomic percentage of zinc and oxygen at 23.61 and 46.57% respectively. X-ray diffraction result was confirmed the single-phase formation of ZnO nanoparticles and the particle sizes were observed to be around 50 to 130 nm. The results showed that ZnO nanoparticles have displayed inhibition zone of 16 and 13 mm against S. aureus and E. coli respectively. Gram-negative bacteria seemed to be more resistant to ZnO nanoparticles than Gram-positive bacteria

Silver nitrate concentration on silver nanoparticles formation attached on cellulose nanocrystal matrix

Cellulose nanocrystals (CNCs) with silver nanoparticle composites are used in various applications, ranging from packaging to biomedical. Therefore, the optimum performance of this hybrid nanomaterial can be achieved by controlling agglomeration in the silver nanoparticle synthesis. The agglomeration behaviour can be monitored by integrating CNCs as polymer matrix during the synthesis. This work aimed to investigate the effect of silver nanoparticles (AgNPs) synthesised from different silver precursor concentrations and loaded on the surface of CNCs. The cellulose nanocrystal was isolated from an oil palm empty fruit bunch (EFB). The AgNPs were synthesised by using the reduction technique of silver nitrate at 0.1 M and 0.5 M concentrations and with the aid of glucose solution. The AgNPs_CNC nanosuspension was analysed by using UV–Vis spectroscopy, FTIR, DSC, and FESEM/EDX. The spectroscopy data from UV–Vis indicated a strong absorption peak at 385 nm due to the formation of the nanoparticles in AgNPs_CNC_0.5 nanosuspension. Meanwhile, the morphological result showed that the AgNPs formed were spherical in shape (57.8 nm) with strong existence of silver, carbon, and oxygen. Therefore, the AgNPs_CNC nanosuspension was successfully synthesised by using 0.5 M silver nitrate with uniform and well-distributed nanoparticles

Inactivation of mucose on bread by using plasma jet

This paper presents the application of cold plasma technology on bread. Plasma is a fourth state of matter apart from solid liquid and gas states. It possesses the same amount of negative and positive ions that are produced from the gas molecule that goes through the electrical breakdown process. Plasma can be produced by injecting high voltage through an electrode. This project aims to develop a plasma jet system that will be able to produce cold plasma with the help of argon as the working gas. Due to its multifunction purpose, cold plasma can be used in many different fields such as biomedical, textile manufacturing, surface modification, food packaging, and many more. In this study, plasma generated with higher voltage may reduce the occupation of mucose on the bread as compares to the control

The potential of gallic acid and ascorbic acid as green reducing agent in ZnO nanoparticle synthesis

In this study, method for the synthesis of zinc oxide (ZnO) nanoparticles for biomedical applications ideally involve the use of nontoxic, less hazardous reducing and capping agent as well as the selection of environmentally benign solvents. In this study, we had investigated the potential of gallic acid and ascorbic acid as both reducing and capping agent in a green approach using microwave heating method. Two parameters including microwave power (400W and 800W) and time of heating (4 and 8 min) were investigated. UV-Vis absorption spectrum showed a typical spectrum for ZnO nanoparticles around 300nm wavelength. This microwave heating method with green reducing and capping agent successfully been advocated as a possible environmentally friendly alternative to chemical methods in synthesizing ZnO nanoparticles. ZnO nanoparticles synthesis from gallic acid and ascorbic acid were both found to exhibit antibacterial activity against a Gram-positive bacterium Bacillus subtilis and a Gram-negative bacterium Escherichia coli

Application of orthogonal optimization and feedforward backpropagation model in the microwave extraction of natural antioxidants from tropical white pepper

The tropical white peppercorns are common commodity crops which have been traditionally used for the treatment of many free radical-related diseases. These medicinal properties are due to the presence of natural antioxidants. This study investigated the combination of microwave extraction parameters for the recovery of natural antioxidants from the white pepper matrix. Microwave-assisted technique was used for the extraction of bioactive oleoresin from white pepper. Taguchi experimental design was employed to investigate the combination of independent extraction parameters for optimal recovery of natural antioxidants. The feed backpropagation artificial neural network model was thereafter applied to optimally predict the result for the different combination of operating parameters. This was achieved by evaluating different algorithms, transfer functions, and neurons. The result obtained from the orthogonal parametric study gave an optimal antioxidant activity of 91.02% at irradiation time of 120 min, microwave power level of 350 W, particle size of 0.300 mm, and liquid-to-solid ratio of 6 mL/g. The gradient descent (GD) algorithm, tansigmoid transfer function, and 4-x-3 topology were used to model the experimental data. A better prediction was then obtained with an overall coefficient (R) and mean square error (MSE) of 0.9595 and 1.4381, respectively. In this study, the feedforward backpropagation neural network was successfully applied to optimally evaluate the complex relationship between the input extraction parameters and the response

Microwave-Assisted Synthesis for Environmentally ZnO Nanoparticle Synthesis

Zinc oxide (ZnO) nanoparticles are versatile materials in many applications due to their unique chemical and physical properties. Recently, researchers tend to find the fast, simple, cost effective and eco-friendly method to synthesis ZnO nanoparticles. Microwave heating method has special heating capabilities have produced desirable products of ZnO nanoparticles. In this study, ZnO nanoparticles were synthesized by a precipitating method assisted with microwave heating method. Zinc nitrate had been used as zinc salt, sodium hydroxide as reducing agent and gum arabic as stabilizing agent. The objective of this paper was to determine the optimum microwave heating power to obtain small size of ZnO nanoparticles. The powers for microwave heating were selected at 250–850 W with 4 min synthesis time. All the synthesized microwave conditions gave single phase of ZnO with wurtzite structure. Dynamic Light Scattering (DLS) was employed to measure the size of ZnO nanoparticles. The size of ZnO nanoparticles increased with increasing microwave power from 250–850 W. At 350 W, smaller size of ZnO nanoparticles obtained. The Ultraviolet–visible spectroscopy (UV–vis) absorption spectra were found in the range of 340 nm. The Fourier-transform infrared spectroscopy (FTIR) spectra showed peaks range from 424 to 475 cm−1 which indicating standard of Zn–O stretching

Synthesis of chitosan/zinc oxide nanoparticles stabilized by chitosan via microwave heating

Nowadays, zinc oxide (ZnO) has attracted attention in research and development because of its remarkable antibacterial properties. Chitosan/ZnO nanoparticles were successfully synthesized via microwave heating. The objectives of this work were to investigate the effect of stabilizer, power heating and time heating on size of chitosan/ZnO nanoparticles and to determine antibacterial activity against pathogenic bacteria, where chitosan was used as a stabilizing agent. Chitosan/ZnO nanoparticles were analyzed by Fourier Transform Infra Red (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and Zetasizer instrument. The power heating and time heating were varied from 400 to 800 Watt and 4 to 8 minutes, respectively. The presence of chitosan has role on preventing the nanoparticles from agglomeration by producing a milky solution of chitosan/ZnO nanoparticles without any suspensions. The increase of power and time heating improved the size of nanoparticles. The peak in FTIR spectrum at around 427 cm-1 was confirmed the existence of the ZnO phase. XRD patterns showed that the chitosan/ZnO nanoparticles materials were pure phase with average crystalline size is 130 nm. FESEM revealed that chitosan/ZnO nanoparticles were uniformly distributed with the mean value of size is 70 nm and spherical shaped. Further impact of power and time heating on the size of the chitosan/ZnO nanoparticles can be shown by a nanoparticles size distribution with the average of 30 to 90 nm. The results showed that chitosan/ZnO nanoparticles have displayed an antibacterial inhibition zone against Gram-positive S. aureus and Gram-negative E. coli which 16.0 and 13.3 mm, respectively. Chitosan/ZnO nanoparticles were synthesized in this work presented have potential application to prevent bacterial infections