Now showing 1 - 10 of 26
  • Publication
    Whole genome sequence of moderate halophilic marine bacterium Marinobacter litoralis SW-45: Abundance of non-coding RNAs
    ( 2019-07-15)
    Musa H.
    ;
    ; ; ;
    Chinni S.V.
    ;
    Ahmad M.A.
    A report on the de novo Whole Genome Sequence (WGS)of Marinobacter litoralis SW-45, a moderately salt-tolerant bacterium isolated from the seawater in Malaysia is presented. The strain has a genome size of 3.45 Mb and is capable of producing halophilic lipase, protease and esterase enzymes. Computational prediction of non-coding RNA (ncRNA)genes in M. litoralis SW-45 was performed using standalone software known as the non-coding RNA characterization (nocoRNAc). In addition, a phylogenetic tree showing the evolutionary relationship between the strain and other members of the genus Marinobacter was constructed using 16SrRNA sequence information. A total of 385 ncRNA transcripts, 1124 terminator region, and 2350 Stress Induced Duplex Destabilization sites were predicted. The current WGS shotgun project has provided the relevant genetic information that may be useful for the strain's improvement studies. This manuscript gives the first description of M. litoralis with a complete genome.
  • Publication
    Electro-determination of protonation by tungsten anchored carbon nanoparticle on interdigitated gold electrode
    This study presented an enhanced sensitivity of sensing protons (H+) by anchoring tungsten to carbon nanoparticles (WCN) to encourage high current density on the surface of gold interdigitated electrode (AuIDE). The morphology of the sensor evidences the intactness of electrode surface and suitable for WCN modification. To elucidate the study, unmodified AuIDE was compared to the WCN modified surface. Current-volt analysis was compared with electrolyte scouting in the variation of pH by using a picoammater, which supplied 0.0 to 2.0 V with a 0.1 V ramp interval. It was shown that modified WCN gave the sensitivity in the acidic medium (protons) at the pH 4 with a current density value of 2.5 × 10-5 ampere and increased further with lowering the pH to more acidic. This is due to the fact that the tungsten carbon nanoparticle that is anchored offering more electron density and alters the behavior of the chip. Meanwhile, the current density displayed insignificant changes of current density amplification from pH 5 to 12 with the range of 5.91 × 10-9 to 7.36 × 10-8 Ampere. The deposition of WCN on the AuIDE surface chip revealed the successfulness of this nanoparticle in chemically linked with the AuIDE surface and how modified nanoparticle altered the behavior of the sensing element.
  • Publication
    Cellulose nanocrystal production from bleached rice straw pulp by combined alkaline and acidic deep eutectic solvents treatment: optimization by response surface methodology
    The present study aims to develop a statistical model utilizing the response surface methodology (RSM) to investigate the performance of oxalic acid-choline chloride deep eutectic solvent (OA-ChCl DES) in hydrolyzing amorphous domain of the bleached rice straw pulp (BP), while liberating the oxalic acid-choline chloride DES cellulose nanocrystal (OA-ChCl DES CNC). The process parameters, including temperature, reaction time, and BP to OA-ChCl DES mass ratio, were optimized through the RSM coupled with the face-centered central composite design (FCCCD). The mathematical models were generated, while the analysis of variance (ANOVA) was conducted to determine the most significant factors influencing the response which was measured in terms of yield. The findings revealed that the OA-ChCl DES CNC yield as high as 55.08% was attained under the acidic DES hydrolysis conditions of 79.5 Â°C, 4 h, and 1:12.64 mass ratio. This regression model enables researchers to predict the OA-ChCl DES CNC yield with respect to the influencing parameters as well as providing an insight for further scale-up process.
  • Publication
    Effect of latex coating on the physical properties of Calcium Alginate beads
    Alginate has been commonly applied in encapsulation due to its gelling capacity, biocompatibility, and environmentally friendly properties. Alginates can produce a thermally stable and biocompatible hydrogel in the presence of divalent cations such as calcium. However, the high porosity and low physical stability of calcium alginate beads can lead to encapsulation loss and degradation of encapsulated materials. It is speculated that latex coating on the beads can overcome the issues. Hence, this study aims to investigate the effect of latex coating on the physical properties of Ca-alginate beads. An extrusion dripping method was adopted to produce Ca-alginate beads. The beads were multilayer coated with a 5% latex solution. The size and shape of uncoated and coated beads were analyzed using 2D image analysis. The thickness of the latex coating layers was measured layer by layer using a thickness gauge. The results indicated that as the number of coating layers increased, the size of the beads also increased. However, the sphericity of the beads is decreased as the number of layers of latex coating is increased. The thickness of the latex coating increased layer by layer, from 0.017 mm to 0.112 mm. In short, the calcium alginate beads can be coated by latex. The diameter of the bead is significantly increased after two layers of latex coating, and the sphericity of the beads is reduced considerably after two layers of latex coating.
  • Publication
    The effect of stacking sequence and ply orientation on the mechanical properties of pineapple leaf fibre (Palf)/carbon hybrid laminate composites
    In this paper, the effects of stacking sequence and ply orientation on the mechanical properties of pineapple leaf fibre (PALF)/carbon hybrid laminate composites were investigated. The hybrid laminates were fabricated using a vacuum infusion technique in which the stacking sequences and ply orientations were varied, which were divided into the categories of cross-ply symmetric, angle-ply symmetric, and symmetric quasi-isotropic. The results of tensile and flexural tests showed that the laminate with interior carbon plies and ply orientation [0â—¦, 90â—¦ ] exhibited the highest tensile strength (187.67 MPa) and modulus (5.23 GPa). However, the highest flexural strength (289.46 MPa) and modulus (4.82 GPa) were recorded for the laminate with exterior carbon plies and the same ply orientation. The fracture behaviour of the laminates was determined by using scanning electron microscopy, and the results showed that failure usually initiated at the weakest PALF layer. The failure modes included fibre pull-out, fibre breaking, matrix crack, debonding, and delamination.
      26  1
  • Publication
    Comparative study on mechanisms of gases release from Ca-alginate beads
    ( 2024)
    Yee-Ming Peh
    ;
    ; ; ; ; ;
    D.F.A. Riza
    ;
    N. Izza
    ;
    K. Gustinasari
    ;
    I.K. Maharsih
    ;
    W.B. Sunarharum
    ;
    M. Nurcholis
    ;
    B.S.D. Dewanti
    ;
    V.T. Widayanti
    ;
    E. Mufidah
    ;
    I. Qisthiya
    ;
    D. Karadag
    ;
    S. Idrus
    ;
    H. Umakoshi
    ;
    Y.C. Lee
    ;
    D. Fatchurrahman
    ;
    M. Zhu
    ;
    K.A. Omwange
    ;
    T. Addini
    Calcium alginate (Ca-alginate) beads have attracted considerable attention as carriers for the controlled release of volatile compounds due to their biocompatibility and tunable properties. This study aimed to compare the release of ethylene and carbon dioxide gas from Ca-alginate beads. Ca-alginate beads were prepared from a sodium alginate solution containing ethephon and calcium carbonate as the gas-forming agent. The resulting solution was then extruded into a calcium chloride solution. The gas release behavior was studied by monitoring the concentration of released gases over time using gas detectors. Extrusion tip diameter, alginate concentration and gas-releasing agent concentration were systematically varied to assess their effect on the gas release rate. The results indicated distinct release patterns for ethylene and carbon dioxide gas. Ethylene gas exhibited a relatively slower and sustained release, while carbon dioxide gas exhibited a more rapid release. Moreover, the bead size influenced the gas release, with larger beads displaying faster release rates for ethylene and carbon dioxide gas. The concentration of alginate also played a role in modulating the release kinetics, with higher alginate concentration resulting in slower gas release. The findings have implications for designing and optimizing Ca-alginate-based systems for agricultural applications, including plant hormone delivery and modified atmosphere packaging.
      1  38
  • Publication
    Effects of ply orientations and stacking sequences on impact response of Pineapple Leaf Fibre (PALF)/Carbon Hybrid Laminate composites
    This study investigated the impact response behaviours of pineapple leaf fibre (PALF)/carbon hybrid laminate composites for different ply orientations and stacking sequences. The laminates were manufactured using a vacuum infusion approach with various stacking sequences and ply orientations classified as symmetric quasi-isotropic, angle-ply symmetric, and cross-ply symmetric. The laminates were analysed using an IMATEK IM10 drop weight impact tester with an increment of 5 J until the samples were perforated. This investigation reveals that the overall impact properties of PALF and carbon as reinforcements were improved by a beneficial hybridised effect. The laminates with an exterior carbon layer can withstand high impact energy levels up to 27.5 J. The laminate with different stacking sequences had a lower energy transfer rate and ruptured at higher impact energy. The laminates with ply orientations of [0°/90°] and [±45°]8 exhibited 10% to 30% better energy absorption than those with ply orientations of [±45°2, 0°/90°2]s and [0°/90°2, ±45°2]s due to energy being readily transferred within the same linear ply orientation. Through visual inspection, delamination was observed to occur at the interfaces of different stacking sequences and ply orientations.
      2  15
  • Publication
    Turning oil palm empty fruit bunch waste into substrate for optimal lipase secretion on solid state fermentation by Trichoderma strains
    ( 2017-12-01)
    Haliru Musa
    ;
    Pang Chien Han
    ;
    ; ;
    Mohd Azmier Ahmad
    This study is aimed to improving extracellular lipase production by Trichoderma strains using oil palm empty fruit bunch (OPEFB) medium on solid state fermentation with the assistance of statistical optimization. Two selected Trichoderma strains (Trichoderma sp.1 and Hypocrea neorufa.1) with high lipase producing potential were employed in a stepwise optimization. Initially, the influence of nutritional (carbon, nitrogen sources, and inducers) and environmental (moisture and temperature) factors on lipase production was evaluated using One-Factor-At-A-time (OFAT) method. Next, three most influential factors (Glucose, Urea and Olive oil) resulting from OFAT were optimized for lipase production by Trichoderma sp.1 using the central composite design under response surface methodology. Experiments conducted under optimum conditions (10.38% (w/w) glucose, 0.86% (w/w) urea, and 7.38% (v/w) olive oil) were further improved the lipase production from 0.195 to 0.390 Ug−1, which is about 2 folds greater than un-optimized condition. This study demonstrated that OPEFB can be utilized as inexpensive substrate for improving the lipase secretion by Trichoderma sp.1.
      16  1
  • Publication
    Methane Biogas Production in Malaysia: Challenge and Future Plan
    (Hindawi Limited, 2022-01-01)
    Amin M.A.
    ;
    ;
    Yin L.S.
    ;
    ;
    Shoparwe N.F.
    ;
    Makhtar M.M.Z.
    ;
    Yaser A.Z.
    Biomethane is a sustainable energy that is produced from an organic and renewable resource. As the second-largest oil palm producer in the world, palm oil mill effluent (POME) is the primary source of biomethane generation in Malaysia. POME is the by-product of palm oil extraction and is extensively employed as a feedstock for the production of biomethane. Malaysia has an equatorial environment with humid and hot weather; this climate is conducive to the cultivation of numerous agricultural crops. A considerable number of agricultural wastes and residues are produced by agricultural crops, however, only 27% of them are used as fuel or to create useable products. Several publications have been published on the production of biomethane from POME; nevertheless, additional research is required on the use of other bioresources and technologies for biomethane production in Malaysia. In addition, there is a lack of comprehensive information on the future development of biomethane production in Malaysia; thus, to fill this gap, this review paper focuses on the challenges and future of Malaysia, which puts an emphasis on POME and also includes other alternative options of bioresources that can be the future feedstock for biomethane production in Malaysia. To the best of our knowledge, this is the first paper to provide a comprehensive overview of the biogas trend in Malaysia in terms of challenges and current biomethane development, as well as detailed information on a number of leading companies that are currently active in Malaysia biogas industry.
      32  2