Production of violacein nanoparticles via sonication technique with the aid of surfactants as stabilizer

Violacein, a violet pigment produced from Chromobacterium violaceum UTM5, has gained interest due to its biodegradability and pharmacological properties. However, its high production cost and limited solubility in water have become the major stumbling blocks for the pigment to be applied in different industries. In this study, liquid pineapple waste was used as an alternative inexpensive growth medium for bacteria cultivation instead of expensive synthetic nutrient broth, thus reducing the production cost of this pigment. The cultivation of C. violaceum in 50 L bioreactor gave a crude yield of 11846 ± 925 mg L-1, which was comparable to the yield obtained using commercial growth medium. The crude pigment was successfully extracted using ethyl acetate. The presence of violacein, the major active compound of the crude pigment, was confirmed using high performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectrophotometry (UV-Vis). Thermal gravimetric analysis was used to determine crystallinity and thermal degradation while Zetasizer analyzer was used to identify the isoelectric point, stability at various pHs, and particle size of violacein. Violacein nanoparticles were produced via sonication technique, with the aid of surfactants (Tween 80, Triton X-100, sodium dodecyl sulfate and dodecyltrimethylammonium bromide) as solubilizing and stabilizing agent, to address the violacein’s poor solubility in water. The violacein nanoparticles were characterized using UV-Vis spectrophotometry, FTIR, thermal analysis and Zetasizer analysis. Water soluble violacein nanoparticles were produced at surfactant concentration greater than its critical micelle concentration, as indicated by FTIR. Zetasizer analysis showed the smallest violacein nanoparticle, which was 131.5 ± 2.001 nm, with polydispersity index (PDI) of 0.180 ± 0.018, which indicated a monodispersed violacein nanoparticle distribution. The thermal analysis showed that violacein nanoparticles were in amorphous state and stable upon dispersion in water, with a zeta potential of -49.8 ± 3.49 mV. The violacein nanoparticles have better solubility than the crude violacein pigment. The solubilized violacein nanoparticles remained well-dispersed upon storage in 28 days at different temperatures. In addition, the violet color of the violacein nanoparticles was maintained at pH range of 3 to 11, temperatures of up to 60°C, and under dark condition, despite its nanoscale size. Higher degradation rate was observed at high temperature and upon light illumination, with k = 6.51 × 10-3 h-1, t1/2 = 148 h and k = 6.75 × 10-4 h-1, t1/2 = 1027 h, respectively, following the first-order kinetics. In conclusion, this study confirmed the feasibility of using liquid pineapple waste as cheap growth medium for cultivation of C. violaceum UTM5 in pilot scale (50-L bioreactor) while production of water-soluble violacein nanoparticles via sonication method with the aid of surfactants as stabilizers would increase its usefulness, especially in pharmaceutical industry

Effectiveness of 2-D resistivity survey to identify lineament (fault) from photolineament interpretation – case study at Kampung Dato’ Mufti, Ampang, Selangor

Lineaments play an important role in the stability of structures such as slopes, foundations, dams and buildings. Identification of the presence of lineament is important especially at planning and construction stage to enable mitigation measures/controls can selected earlier. The combined techniques of satellite image downloaded from Google Earth interpretation and electrical resistivity survey can assist in the identification and verification process of lineament structures. In this study, interpretation of lineament was done using satellite images Google Earth in the laboratory. Orientation and position of every lineament was determined accurately in the field. Electrical resistivity survey was conducted using Wanner configuration that cross the lineament in the field. The electrical resistivity results showed the presence of lineament structural in the pseudo section and prove the effectiveness of combination of both techniques to detect and confirm the presence of structural lineament

Synthesis and optimization of nano-sized bacterial-based violacein pigment using response surface methodology

Violacein from Chromobacterium violaceum has raised the enthusiasm of researchers in conducting comprehensive studies on these pigments due to their diverse biological activities including antibacterial and antioxidant properties. However, a limitation related with the solubility of the violacein pigment, by which it is commonly dissolved in toxic solvents such as dimethyl sulfoxide and methanol instead of being soluble in biological fluids and water. Hence, this study provides a method to synthesis the violacein pigment in nanoscale through an encapsulation technique using chitosan-tripolyphosphate (Cs-TPP) nanoparticles. The synthesis of nanoparticles in this study involved ionic gelation between chitosan and tripolyphosphate (TPP), in which several parameters were taken into consideration in order to control the size and dispersion stability of the violacein pigment in the suspension. Preparation parameters, including the concentration of chitosan, TPP and pigment as well as the mass ratio of chitosan to TPP, were optimized using Response Surface Methodology (RSM). Minimum particle size of 149.0 nm with zeta potential of +23.40 mV was obtained at the optimal formulations of 2.33 mg/mL of chitosan, 1.5 mg/mL of TPP, and 1 ppm of violacein pigment and at mass ratio of chitosan:TPP of 7:1. This nano-sized violacein pigment is expected to be applied as safe additive, colorant, and therapeutic agents. Meanwhile, RSM in the study could provide the optimal formulations for producing stable nano-sized violacein pigment

Beyond conventional biomass valorisation: pyrolysis-derived products for biomedical applications

Biomass valorisation is conventionally associated with the production of green biofuels. However, this could extend beyond the conventional perception of biomass application into other domains such as medical sciences. Acid condensate (AC) obtained from pyrolysis promises a good potential for biomedical applications, notably for its antimicrobial, antioxidant, and anti-inflammatory properties. In this study, concentrated AC extract (CACE) obtained from microwave-assisted pyrolysis of palm kernel shells was fractionated, and the resulting fractions were pooled according to similar thin layer chromatography profiles into combined fractions (CFACs). CFACs were evaluated for total phenolic content, antioxidant level, cytotoxicity, and wound healing activities toward human skin fibroblast cells (HSF 1184). CFAC-3 showed the highest total phenolic content (624.98 ± 8.70 µg GAE/mg of sample) and antioxidant activities (DPPH IC50 of 29.47 ± 0.74 µg/mL, ABTS of 1247.13 ± 27.89 µg TE/mg sample, FRAP of 24.26 ± 0.71 mmol Fe(II)/mg sample, HFRS of 257.74 ± 1.74 µg/mL) compared to CACE (DPPH IC50 of 81.76 ± 2.81 µg/mL, ABTS of 816.95 ± 30.49 µg TE/mg sample, FRAP of 9.22 ± 0.66 mmol Fe(II)/mg sample, HFRS of 689.30 ± 36.00 µg/mL), no cytotoxic properties at =50 µg/mL, and significantly faster wound closure (at 1.25 µg/mL) compared to the control 12 h after treatment. The phosphorylation of the phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT) were upregulated, thus indicating that wound healing of CFAC-3 followed through this signalling pathway. To conclude, phenolic-rich CFAC-3 obtained from the pyrolysis of palm kernel shells demonstrated potential biomedical application as an alternative wound healing agent with high antioxidant and wound-healing activity. To the best of our knowledge, this was the first study to report on the wound healing activity of AC and its wound healing mechanism

Characterization and antiinflammatory properties of fractionated pyroligneous acid from palm kernel shell

Pyroligneous acid (PA) obtained from slow pyrolysis of palm kernel shell (PKS) has high total phenolic contents and exhibits various biological activities including antioxidant, antibacterial and antifungal. In this study, PA obtained using slow pyrolysis method and fractionated using column chromatography was characterized (chemical and antioxidative properties) and investigated for its cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibition activities using the in vitro and in silico approaches. The F9 PA fraction exhibited highest total phenolic content of 181.75 ± 17.0 μg/mL. Fraction F21–25 showed ferric reducing antioxidant power (FRAP) (331.80 ± 4.60 mg TE/g) and IC50 of 18.56 ± 0.01 μg/mL towards COX-2 and 5.25 ± 0.03 μg/mL towards the 5-LOX enzymes, respectively. Molecular docking analysis suggested favourable binding energy for all chemical compounds present in fraction F21–25, notably 1-(2,4,6-trihydroxyphenyl)-2-pentanone, towards both COX-2 (− 6.9 kcal/mol) and 5-LOX (− 6.4 kcal/mol) enzymes. As a conclusion, PA from PKS has the potential to be used as an alternative antioxidant and antiinflammatory agents which is biodegradable and a more sustainable supply of raw materials

Modeling on the association between road environment contributory factors and road traffic accidents for Federal Road 2

Road safety research has revealed a number of factors that may lead to road traffic accidents such as the driver's fault, vehicle 's failure and roadway condition and environment. Many studies have been done extensively focu sing on the first two factors and countermeasures always aimed at changing and controlling the human beings in the system.However, road environment also can have strong influences that lead to road crashes for instance the weather and lighting conditions especially when travelling during night time in the raining weather. The possible causes that contribute to those crashes will be poor visibility of lighting, poor sign quality and also might be because of the slippery pavement. Prior to that issue, this study was conducted to examine the association between road environment factors which directly focusing on the travelling periods of time of the day, day of the week and month of the year to the number of road traffic accidents. To achieve this study, a stretch road of 63km Jalan Kuantan - Maran (Federal Road 2) was selected to serve as a study area. It is a dual 2-lane carriageway that forms the backbone of Kuantan road network which experiences high traffic volume as it caters as a main trunk road that link Kuala Lumpur and east coast region. The main data of road accident cases at this study area were obtained from Royal Police Malaysia, Traffic Units. For the purposes of data processing and interpretation, those accidents cases were disaggregated by six similar sections denoted as Section 1 to Section 6. Then, the Correlation and Inferential Analysis of Non- Parametric Test forms the basis for testing the association between each travelling periods of time, day and month to the number of road traffic accidents by using the Statistical Package for Social Sciences (SPSS) Version 12.0. Based on the analysis, the result demonstrated that there was a weak correlation develops on each time of the day, day of the week and also month of the year to the number of road traffic accidents along Jalan Kuantan - Maran (Federal Road 2). Anyhow there is a strong significance value between these factors to the number of accidents. In other words, time, day and month do have influence to the number of accidents along Jalan Kuantan - Maran (Federal Road 2). However, it is recommended that further studies need to be carried out for validation of the result

Phenolic compound derived from microwave-assisted pyrolysis of coconut shell: Isolation and antibacterial activity testing

Indonesia is rich in natural resources, coconut plantation being one of them. The coconut processing industry produces coconut shell (CS) waste. The most effective technique to increase the value of this waste is to convert CS biomass through pyrolysis process. This research focuses on intensification of conversion process of CS by Microwave-Assisted Pyrolysis (MAP) to obtain PA. PA contains phenolic compounds which have antibacterial properties so they can be formulated as an antibacterial agent. CS has moisture and ash content of 8.89% and 0.21%, respectively. PA was produced from the MAP of CS at 600W at 450' and 500oC for 10, 20, and 30 minutes. The PA was extracted using ethyl acetate to obtain phenolic contents. Optimum pyrolysis condition was found at 400oC for 30 minutes and yield of PA was determined at 32.20 g with total phenolic content (TPC) of 112.13 mg GAE/g. The inhibition zone of phenolic extract from coconut shell (PECS) using E. Coli was determined within 22-25 mm that quantitatively PECS can effectively kill bacteria. PECS by MAP and its aplication as an antibacterial agent has never been performed, so this work is an important contribution in the intensification of pyrolysis and in medical field