Now showing 1 - 3 of 3
  • Publication
    Structural and mechanical variations of major ampullate silk spun by Malaysian Nephila pilipes spider
    Major ampullate (MA) silk is a natural biomaterial, spun by spiders with exceptional mechanical characteristics. Most researchers who studied MA silk structure were primarily interested in the properties of a dragline thread that protrudes from the spider’s spigot when being chased by its predator. Apart from the dragline, the MA silk fibers may also be found in three pivot threads of the orb web known as the mooring, framework, and radial. However, it is currently uncertain whether the MA silk in these threads has properties similar to the dragline thread. Thus, this work attempted to compare the properties of MA silk fiber in the mooring, framework, radial, as well as the dragline threads. The MA silk fibers in mooring thread were found to exhibit significant quantity of MA fibers (12 ± 5.0 fibers per thread), thickness diameter (11.7 ± 0.6 μm), and supercontraction effect (high swelling ratio of 18.6), with an outstanding combination of strength (4464 MPa) and toughness (875 MJ/m3), outperforming the dragline thread. Positive correlation was found between the diameter of MA fibers and supercontraction effect and between the number of MA fibers and tensile strength. These findings might be modeled as a fundamental guide in silk spinning for future synthetic MA silk fiber development with extraordinary mechanical performance.
  • Publication
    Pretreatment of Leucaena Leucocephala Using Deep Eutectic Solvent for Ethanol Production by Kluyveromyces Marxianus UniMAP 1–1
    Conventional pretreatment methods such as alkaline and acid pretreatment which were used in biorefineries to dissolve lignin and hemicellulose faces many drawbacks. These pretreatment methods were considered as toxic not only to the environment, but also to the biomass as further treatment using these solvents will lead to the production of hydroxymethyl furfural (HMF) and furfural, which can inhibit the production of ethanol. Recently, deep eutectic solvents (DES) have grown in popularity as an alternative solvent to substitute conventional pretreatment solvents. DES have a great number of advantages such as biodegradability, non-toxic, low volatility and low cost. Furthermore, DES also is a powerful solvent to dissolve lignin, thus this makes DES a superior solvent to be used in biorefineries compared to alkaline and acid pretreatment. In this study, Leucaena leucocephala seeds and pods were treated with choline chloride – glycerol (ChCl – Gly) based DES at 1:2 molar ratio, and the performance subjected to sugar released and ethanol production were analyzed using high performance liquid chromatography (HPLC). The values were then compared with the conventional pretreatment methods as the controls. The results suggested that DES pretreatment released slightly higher total sugar, 29.28 g/L compared to alkaline and acidic pretreatment at 28.77 and 24.94 g/L, respectively. On the other hand, the yield of ethanol after fermentation in DES treatment were among the highest, which was 0.287 g ethanol/g glucose with 56.27% conversion compared to theoretical yield. The purpose of this report is to offer further information in the interest of making DES as a good replacement for the conventional pretreatment method.
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  • Publication
    Production of fermentable sugars by Oil Palm Fronds (OPF) through fungal solid state bioconversion
    (IOP Publishing, 2020) ;
    Norainon Maulad Nashir
    ;
    Nor ‘Izzah Zainuddin
    Oil palm fronds (OPF) are an abundant lignocellulosic waste generated from the oil palm field. In this study, efficient saccharification processes of oil palm fronds (OPF) through fungi bioconversion were explored. The objective of this study is to investigate the effectiveness of Aspergillus niger (A.niger), Phanerochaete chrysosporium (P. chrysosporium) and Aspergillus terreus (A. terreus) UniMAP AA-1 in producing fermentable sugar as well as the important parameters that can affects the bioconversion process. Solid-state fermentation process was carried out with the total working volume of 20 g at 30°C for 7 days. Throughout this study, A. terreus UniMAP AA-1 was found as the most potential microorganisms in converting cellulose into glucose compared to the other microorganisms, which were A. niger and P. chrysosporium. Optimization experiment of fermentable production from Aspergillus terreus UniMAP AA-1 was designed using Central Composite Design (CCD). CCD identified optimum condition for inoculum size, which was 4 % (w/v) and pH 8 in optimization study using Response Surface Methodology (RSM) and maximum fermentable sugar produced was 3.6732 mg/mL. The data obtained from this study may applicable for scale-up process of fermentable sugars production from OPF in the future.
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