Category Archives: 2019 Vol 31 March

MINIMAL INHIBITORY CONCENTRATION OF HYGROMYCIN FOR SELECTING TRANSFORMED OIL PALM EMBRYOGENIC CALLI

Determination of optimum concentrations for a selection agent is important in obtaining true transformants during the selection stage. In this study, the minimal inhibitory concentrations of hygromycin for four different types of oil palm embryogenic calli (suspension, fine, yellowish and whitish) that were cultured on proliferation, maturation and regeneration media were assessed. The embryogenic calli were cultured on media supplemented with different concentrations of hygromycin. Data on embryogenic callus weight increment was recorded monthly for six months during subculturing. Our results demonstrated that oil palm embryogenic calli cultured on regeneration media (EC) were very sensitive to hygromycin. The growth of embryogenic calli was affected at a relatively low concentration of hygromycin as compared to suspension calli that were cultured on proliferation media (L-1). The regeneration of fine, yellowish and whitish embryogenic calli was completely inhibited at 5-6 mg litre-1 of hygromycin. In contrast, higher concentration of hygromycin at 10 mg litre-1 is needed to inhibit the proliferation of suspension calli cultured on proliferation media. The hygromycin concentrations determined for each of the embryogenic callus types can be used as a guideline to select true transformants in future oil palm transformation works.

ISOLATION OF AN OIL PALM CONSTITUTIVE PROMOTER DERIVED FROM UBIQUITIN EXTENSION PROTEIN (uep2) GENE

Constitutive promoters are essential component in genetic engineering. The promoters are usually derived from genes that are constitutively expressed or function as housekeeping genes. In this study, the ubiquitin extension protein (uep2) gene was identified as a constitutively expressed gene in oil palm. The 5’ region of the oil palm uep2 gene was isolated and the promoter truncation analysis was performed. The full length of uep2 (uep2a) and its truncation derivatives (uep2b and uep2c) were linked to β-glucuronidase (gus) reporter gene. The strength and the activity of the uep2 promoter were transiently evaluated in various oil palm tissues and tobacco leaves. Histochemical GUS analysis showed that the activity of truncated uep2b promoter was higher than the full length promoter and uep2c derivative in most tissues tested. Result also showed that uep2b was capable of directing the expression of GUS in all tissues with the high activity detected in oil palm embryoid, green leaves, and tobacco leaves. The full length of uep2 (uep2a) promoter also exhibited the ability to direct the expression of GUS in all tissues with the high activity detected in the plantlet stem. By contrast, although the uep2c showed high activity in young leaves and embryoid, a significant decrease of GUS expression was seen in green tissues. These results indicated that the region between position -1096 and -3237 is essential for constitutive transcriptional regulation as deletion of the region resulted in a significant decrease in the promoter activity. Though maize ubi1 and CaMV35S promoters showed a relatively higher activity than uep2, the uep2 has the ability to induce the constitutive GUS expression in all tissues tested. These results showed that 5’ flanking region of uep2 gene is active in oil palm and tobacco, suggesting that the promoter could be used as an alternative promoter for driving constitutive expression of transgenes in oil palm and other plants.

EVALUATION OF GFP-BASED SYSTEM FOR PRE-CRYSTALLISATION STUDY OF EgKUP MEMBRANE PROTEINS

Elucidation of atomic structures of membrane proteins (MP) is of great importance for comprehensive understanding of their functions and mechanism of actions. Determination of high resolution protein structures by X-ray crystallography requires crystallisation of a protein of interest. Obtaining wellordered protein crystals however, is not an easy task and many factors can contribute to unsuccessful crystallisation. The situation will get much trickier when dealing with MP owing to the fact that they are not soluble in their innate state after extraction from the lipid bilayer environment. Unless appropriate detergents are used to stabilise proteins by mimicking their native environment, MP tend to unravel, thus becoming dysfunctional. This study evaluates the effectiveness of using Green Fluorescence Protein (GFP)-based system as C-terminal tag in Saccharomyces cerevisiae for pre-crystallisation study of Elaeis guineensis MP from the K+ Transporter/ K+ Uptake Permease/High Affinity K+ (KT/KUP/ HAK) superfamily. KT/KUP/HAK are one of the most important MP responsible for potassium uptake in plants. Development of recombinant expression system for high-level protein production is necessary as the vast majority of MP cannot be obtained in sufficient quantities from their native environment. The precrystallisation analyses were conducted on three EgKUP-GFP fusions, namely EgKUP3-GFP, EgKUP8- GFP and EgKUP11-GFP. The analyses involved whole-cell florescent count of each fusion protein using spectrofluorometer, protein integrity assay by SDS-PAGE, cellular localisation by confocal fluorescence microscopy and effects of various detergents towards EgKUPs’ stability and monodispersity using Fluorescence Size Exclusion Chromatography (FSEC). Results from the evaluation, associated problems and proposed troubleshootings are discussed.

IDENTIFICATION OF CHELIDONIC ACID AND ASPARAGINE IN Ganoderma boninense– INOCULATED OIL PALM SEEDLINGS

Basal stem rot (BSR) caused by Ganoderma is the major disease of oil palm and therefore, of great economic importance to the Malaysian oil palm industry. Study of the biochemical interaction between Ganoderma boninense and the oil palm was carried out using a metabolomics-based approach. The aim of this study is to identify metabolites that are responsible for classification of different types of treatments that have been applied on the oil palm seedlings namely T1, inoculation with rubber wood block (RWB) fully colonised with G. boninense PER71; T2, inoculation with uncolonised RWB and T3, oil palm seedlings without inoculation of RWB. Spear leaves from oil palm seedlings were collected and analysed using liquid chromatography-mass spectrometry (LC-MS). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to distinguish components of interest and potential markers, which were identified by employing a mix of accurate mass, tandem MS (MS/MS) strategies with searches in spectral libraries. Chemometric results from oil palm spear leaf LC-MS data of 48-week after infection revealed asparagine and chelidonic acid abundance in T1 treated samples which was further confirmed using commercial chemical standard.

INFLUENCE OF SOIL COMPACTION ON OIL PALM YIELD

The threat of soil compaction is greater today because of the marked increase in the size and weight of machinery used in oil palm plantations. Concern has grown on their direct effects on soil physical properties and indirect effects on crop yield. Therefore, the objective of this study was to determine the influence of soil compaction on yield of oil palm planted on a clay-textured Bernam soil series (Typic Endoaquepts). Compaction treatments were imposed for six consecutive years with combination treatments of trailer weights and transportation frequencies. Although soil compaction was expected to reduce the oil palm yield, the results showed that an increase in soil bulk density (BD) and reduction in total porosity (TP) were beneficial to the oil palm. The fresh fruit bunch (FFB) yield, bunch number, and bunch weight were significantly increased by about 8%-11%, 7%-9%, and 2%-3% respectively, in the compacted plots as compared to control. The three rounds (3R) per month transportation frequency resulted in higher FFB yield and bunch numbers for all compaction treatments. Thus, compaction may not be a problem to oil palm planted on Bernam soil series, but further study needs to be carried out on other soil series.

IMPACT ANALYSIS OF CLIMATIC FACTORS ON VEGETATIVE GROWTH, YIELD AND COLD RESISTANCE OF OIL PALM INTRODUCED IN DIFFERENT REGIONS OF GUANGDONG PROVINCE, CHINA

Climatic data in six regions of Guangdong Province, China were collected and analysed with the traits observed from April 2010 to April 2015. Climatic factors showed significant regional and annual changes except annual rainfall (AR) in different studied regions. Annual sunshine hours (ASH) was negatively correlated with bunch number (NB), bunch weight (ABW) and fresh fruit bunch (FFB) yield, but positively with abortion ratio of bunch (ABR). Furthermore, sex ratio of female inflorescences and bunches to total inflorescences and bunches (SR) had positive correlations with mean annual temperature (MAT) and extreme minimum temperature (EMT), while semi-lethal temperature (LT50 ) was positively correlated with MAT and mean effective accumulated temperature above 10oC (MAAT), and negatively with AR. However, annual temperature of the coldest month (ATCM) was not significantly affected with other traits. ASH was the major determinant of ABW, FFB and ABR, and NB and LT50 were mainly determined by MAAT. The major determining factor of frond production (FP) and fruit compaction rate (FCR) for MAT, and normal fruit weight per bunch (ANFW) for AR. Percentage of normal fruit weight to bunch weight (F/B) and abortion ratio of female inflorescence (RAFM) were mainly determined by ATCM, and SR by EMT.

THE EFFECT OF VIBRATION ISOLATOR ON THE MAGNITUDE OF HAND-ARM VIBRATION (HAV) OF THE OIL PALM MOTORISED CUTTER (CANTAS)

The oil palm motorised cutter (CANTAS) is categorised as a type of machine that generates vibration which could cause hand-arm vibration syndrome (HAVS). It is necessary that the level of vibration be managed and controlled. This article highlights a study on the effect of two types of vibration isolators (D1 and D2) on the magnitude of hand-arm vibration (HAV) on two types of CANTAS (MC1 and MC2) at two holding points (P1- at the throttle and P2 – at the pole). The results showed that the use of isolator reduced the magnitude of HAV for MC2, but not for MC1. Fixing D1 to MC2 reduced HAV at P1 and P2 by 54% and 45%, respectively, while fixing D2 to MC2 reduced HAV at P1 and P2 by 28% and 42%, respectively. The results disclosed that D1 had a better effect on HAV reduction for MC2 where the average HAV was reduced by 49.5%. Minimum HAV of MC2 was obtained when D1 was fixed at 70 cm from the engine. The study discovered that installing isolators to MC2 reduced the magnitude of HAV significantly which helps to reduce the risk of HAVS to the operator.

LOW-TEMPERATURE DIRECTED INTERESTERIFICATION INCREASES TRIUNSATURATED AND TRISATURATED TRIACYLGLYCEROLS OF PALM OIL AND AFFECTS ITS THERMAL, POLYMORPHIC AND MICROSTRUCTURAL PROPERTIES

Directed interesterification (DIE) is an interesterification technique performed at a sufficiently low temperature to allow higher melting triacylglycerols (TAG) to crystallise out as they are formed during the reaction. Thus, DIE is an excellent tool for changing the TAG composition of oils and fats and consequently extends their applications. DIE converts liquid oils into plastic fats, reduces the formation of graininess and improves the plasticity of lard, and increases the unsaturation level of the olein fraction of fats. This study explored the possibility of using lipase-catalysed DIE (EDIE) as a ‘green’ technique to produce palm oil (PO) which is high in triunsaturated (U3) and trisaturated (S3) TAG, which in turn, when fractionated, produce an olein fraction which is high in unsaturated (especially, oleic acid) and a stearin fraction that is high in saturated (especially, palmitic acid) fatty acids. EDIE resulted in a significant (p<0.05) increase in U3 and S3 TAG of PO, from 4.3% and 5.2% before EDIE to 27.6% and 31.9% after EDIE, respectively. The increased content of U3 and S3 TAG subsequently altered the physical properties of PO. Higher U3 TAG content led to an increase in the proportion of the low melting fraction of PO. Meanwhile, the melting point, solid fat content at all temperatures and the proportion of high melting fraction of PO show to increase following the rise in S3 TAG after EDIE. A differential scanning calorimetry melting curve showed that the low and high melting fractions of EDIE PO were distinctively separated, indicating ease of fractionation. EDIE also increased the proportion of β crystals in PO. Thus, its microscopic structure showed dense crystal aggregates with a coarse plate-like and orderly packed structure.

EFFECTS OF PARTIAL REPLACEMENT OF FISH OIL WITH DIFFERENT VEGETABLE OILS ON GROWTH, FEED UTILISATION AND FATTY ACID PROFILE OF HYBRID GROUPER JUVENILE (Epinephelus fuscoguttatus x Epinephelus lanceolatus )

This study was done to investigate the effects of fish oil (FO) replacement with different types vegetable oils (VO) on the growth performance, feed utilisation and fatty acid profile of hybrid grouper juvenile (Ephinephelus fuscoguttatus, ) x giant grouper (Epinephelus lanceolatus, ). Six isoprotein (50%) and isolipid (12%) diets were formulated using 100% FO (as the control) and 50% of FO was replaced with crude palm oil (CPO), refined, bleached and deodourised (RBD) palm olein (POo), crude palm kernel oil (CPKO), corn oil (CO) and coconut oil (COCO). Triplicate groups of hybrid grouper juvenile (11.12±0.04 g) were fed with the experimental diets for a period of 12 weeks. Fish fed with RBD POo diet showed significantly higher growth and slightly better feed efficiency than other diets. The different VO affected the body indices, whole body proximate composition and fatty acid profile of the muscle and liver. However, the survival of fish was not affected by the different diets. Present study suggests that RBD POo is the most suitable VO for hybrid grouper.

THEORETICAL APPROACH OF DFT B3LYP/6-31G (d, p) ON EVALUATING THE PERFORMANCE OF tert-BUTYLHYDROQUINONE AND FREE FATTY ACIDS IN INHIBITING THE OXIDATION OF PALM OLEIN

The effects of adding palmitic acid (PA) and linoleic acid (LA) on the performance of tert-Butylhydroquinone (TBHQ), in inhibiting the autoxidation of palm olein was studied. These fatty acids were employed to test their effectiveness on antioxidant performance, experimentally and theoretically. In experimental studies, palm olein added with fatty acids at four different concentrations in the presence or in the absence of TBHQ were heated in the oven at 60°C for 15 days and collected after 0, 1, 3, 6, 10 and 15 days for peroxide values analysis. In the theoretical study, a quantum mechanical at the theoretical level of DFT B3LYP/ 6-31G (d,p) was used in optimising the molecular structures of single species and complexes, and then tested for physical parameters (dipole moment, stabilisation energy, and bond indexes). It was found in the presence of TBHQ, synergistic behaviour was found between fatty acid and antioxidants. The addition of PA, which is the same as the main component of palm olein, significantly decreased oxidation and peroxide formation, thus gave less effect to the degradation of triacylglycerides. Based on the theoretical calculations, the interaction energy is shown as the major contributor to the performance of the antioxidant.

EFFECT OF EGR & NANOPARTICLES ON PERFORMANCE AND EMISSION CHARACTERISTICS OF A DIESEL ENGINE FUELLED WITH PALM BIODIESEL AND DIESEL BLENDS

This work examines the consequence of employing cerium oxide (CeO2) nanoparticles at a different proportion (30 ppm, 60 ppm and 90 ppm) to palm oil methyl ester and diesel blends (B20) in water-cooled single cylinder four stroke diesel engine. Adding nanoparticles is a strategy to improve the performance and reduce emissions of the biodiesel. Prepared samples are fuelled to diesel engine by admitting exhaust gas recirculation (EGR) of 10% and 20% by volume. The main intention of this study is to lessen the nitrogen oxide (NOX) emissions for diesel and biodiesel blends. Experimental results found a significant reduction NOX, carbon monoxide (CO), smoke and hydrocarbon (HC) emissions at 10% EGR rate. However, brake specific fuel consumption is increased with significant lower brake thermal efficiency by admitting EGR of 20% by volume. Thus, it can be inferred that EGR of 10% by volume is a optimal way on reducing harmful emissions without compromising much on performance aspects of biodiesel fuelled diesel engine.

PERFORMANCE AND EMISSION ANALYSIS OF DIESEL ENGINE USING THERMAL BARRIER COATING AND ADDITION OF CERIUM OXIDE NANOPARTICLES TO PALM BIODIESEL

This work investigates the effect of thermal barrier coating and addition of cerium oxide nanoparticles to the palm biodiesel fuelled diesel engine. The combustion chamber parts of cylinder liner and piston were coated 200 and 100 micron thickness respectively using equal percentages of Yittria Stabilised Zirconia (YSZ) and alumina powder in plasma spraying technique. The 30 ppm and 60 ppm of cerium oxide (IV) nanoparicles were added to the palm biodiesel fuel separately. The performance and pollution parameters were analysed initially using a thermal barrier coated (TBC) engine with neat palm biodiesel. Cerium oxide (IV) nanoparticles were then added to the palm biodiesel and their effects were compared with the base engine. The final performance results showed reduction in the specific fuel consumption on an average of 11.86%, 16.92% and 20.57%, while brake thermal efficiency was increased by 3.21%, 4.28% and 4.82% in neat palm biodiesel fuel, 30 ppm and 60 ppm CeO2 mixed palm biodiesel fuel used thermal barrier coated engine respectively. Carbon monoxide and unburned hydrocarbon emission were reduced by 2.2% and 3.7% and nitrogen oxide emission was increased by 1.7% for thermal barrier coated engine. However, the use of oxygen denoting catalyst of cerium oxide nanoparticles caused a 2.4% reduction in nitrogen oxide emission.

CHARACTERISATION OF EPOXIDISED TRIMETHYLOLPROPANE TRIOLEATE: NMR AND THERMOGRAVIMETRIC ANALYSIS

Epoxy or oxirane compounds have attracted considerable interest and commercial importance in recent years. The study on the synthesis of trimethylolpropane (TMP) ester is well established. However, the study on the epoxidation of the oleyl-based TMP is still limited. Therefore, the present research concerns the characterisation of epoxidised TMP trioleate which could be used as plasticiser, high stability biolubricants and feedstock for the subsequent reaction such as acrylation to produce bio-based polymer and resin. The effect of the molar ratio of ethylenic unsaturation in TMP trioleate to formic acid for in situ peroxidation has been investigated. The resultant epoxidised TMP trioleate containing different numbers of epoxide groups/molecule were synthesised. The high ratio of formic acid to ethylenic unsaturation in TMP trioleate is unfavourable for in situ epoxidation as it yielded lower amount of epoxy ester. The epoxidised TMP tritrioleate was synthesised, confirmed by Fourier transform infrared (FTIR) and the degree of epoxidation (DOE) was quantified by nuclear magnetic resonance (NMR). The epoxidised TMP trioleate which contained TMP 9, 10-epoxystearic acid and TMP 9, 10, 12, 13-diepoxystearic acid were also identified. The thermal stability were compared and it was found that the epoxidised TMP trioleate has lower thermal degradation temperature than TMP trioleate.

ANTIOXIDANT PROPERTIES OF CRUDE AND COLD ETHANOL PRECIPITATED PROTEIN FROM PALM KERNEL CAKE (PKC) AS POTENTIAL COSMECEUTICAL AGENT

Palm kernel cake (PKC) is a by-product obtained from the production of edible oils using oil palm
(Elaeis guineensis). PKC is well-known for its high protein content, therefore, it was chosen as the target
of this research to study its antioxidant properties, which is an important criteria in cosmeceutical industry.
Our studies showed that, the extraction of crude protein at 80°C resulted in the highest total phenolic
content (TPC) and protein yield. It was further seen that precipitation using 80% cold ethanol following
protein extraction at 80°C gave the best protein yield of 56.6%. The antioxidative activity of this precipitated
protein was expressed as IC50 for 1-diphenyl 1-2-picrylhydrazyl (DPPH) radical-scavenging capacity
(517±0.016 mg ml-1), 2, 2′-azino-bisC3-ethylbenzothia zoline-6-sulphonic acid (ABTS) radical-scavenging
capacity (0.047±0.009 mg ml-1) and ferrous ion-chelating (FIC) ability (21±0.13 mg ml-1). Meanwhile, the
reducing power and TPC were 0.156±0.006 trolox equivalent antioxidant capacity (TEAC) mmol g-1 dry
weight (DW) and 25.10±0.58 gallic acid equivalent (GAE) μg g-1 DW respectively. The Pearson correlation
test further revealed a significantly moderate to strong positive relationships between antioxidant properties
with protein content and antioxidant properties with TPC. Taken together, both, the crude and precipitated
protein obtained from PKC showed substantial amount of antioxidative activities, which could be used as
sustainable source of antioxidant peptides in enhancing the quality of cosmeceutical products.

EFFECTS OF OXIDISED OILS ON INFLAMMATION-RELATED CANCER RISK – Review Article

The practice of using cooking oils that are heated repeatedly is common to reduce the expenses of food preparation. However, this will result in lipid peroxidation, which generates compounds that are toxic to human health. Prolonged consumption of oxidised oils may affect lipid metabolism, which generates free radicals and products that will lead to pro-inflammatory pathways. A number of cellular, animal and clinical studies have revealed the effects of oxidised oils on inflammatory responses. By-products of lipid peroxidation, including trans, trans-2,4-decadienal (2.4-De), 4-hydroxy-2-hexenals (4-HHE) and malonaldehyde (MDA) can be found significantly in samples treated with oxidised oils. Besides, the release of inflammatory biomarkers or cytokines will be induced due to the enhanced degree of oxidative stress. Inflammation has been acknowledged to be linked to increased risk of cancer. Therefore, the consumption of repeatedly heated oils, which have higher level of oxidation may potentially lead to cancer progression. The possible cancer risk induced by the dietary intake of pro-inflammatory oxidised oils, methodology considerations and limitations of studies related to cancer risk induced by pro-inflammatory oxidised oils will be discussed in this review.