Category Archives: 2015 Vol 27 March

IDENTIFICATION OF GENES INVOLVED IN SOMATIC EMBRYOGENESIS DEVELOPMENT IN OIL PALM (Elaeis guineensis Jacq.) USING cDNA AFLP

Oil palm (Elaeis guineensis Jacq.) belongs to the Arecaceae family and is the largest source of edible vegetable oil worldwide. Micropropagation of oil palm by somatic embryogenesis takes a long time from callus initiation to the production of plantlets. This research project aims to investigate the genes involved in somatic embryogenesis of oil palm during the tissue culture process. We applied the cDNA-AFLP technique to identify genes associated with somatic embryogenesis in oil palm during the tissue culture process. Sixty-four EcoRI/MseI AFLP primer combinations produced a total of 1449 transcription-derived fragments (TDF), of which 1193 TDF (82.33%) showed polymorphism. The most abundant up-regulated and down-regulated transcripts during somatic embryogenesis were selected for characterisation. Sixtyfive TDF were sequenced, and 34 distinct sequences were obtained. Primer pairs were successfully designed for 18 of these sequences. The differential expression of the 18 distinct sequences was analysed by using semi-quantitative RT-PCR. The information obtained from this study provides prior knowledge about the genetic underlying the somatic embryogenesis in oil palm, and will be the starting point that reveals the genetic components and mechanism in the control of this process in the future.

THE EFFECT OF Ganoderma boninense INFECTION ON THE EXPRESSIONS OF THIAMINE (vitamin B1) BIOSYNTHESIS GENES IN OIL PALM

Thiamine pyrophosphate (TPP), an active form of thiamine plays a fundamental role as an enzymatic cofactor in universal metabolic pathways including glycolysis and pentose phosphate pathway. We identified and amplified gene transcripts of the first two enzymes in the pathway, THI1/THI4 and THIC. Primers were designed based on sequence comparison of the genes from Arabidopsis, rice and maize. We also investigated the relationship between expression of thiamine biosynthesis genes and stress. This is due to findings suggesting that TPP has functions other than as a cofactor in response to stress in plants. The response of THI1/THI4 and THIC gene transcripts towards the infection of Ganoderma boninense on oil palm was observed. The gene transcripts’ expressions were analysed via RT-PCR over a time course after infection. For THI1/THI4, the percentage of level of expression for healthy oil palm is 29.79% and an increase up to 70.21% was observed in artificially infected oil palm seedlings. For THIC gene, in healthy oil palm, the level of expression was 45.83% but when infected, it increased slightly up to 54.17%. Our results support the suggestion that thiamine may play an important role in the protection of cells against stress as it leads to an overexpression of thiamine in general.

ISOLATION OF ACTINOMYCETES FROM RHIZOSPHERE OF OIL PALM (Elaeis guineensis Jacq.) FOR ANTAGONISM AGAINST Ganoderma boninense

This study reports the isolation and screening of actinomycetes from the rhizosphere of oil palm (Elaeis guineensis Jacq.) for antagonism against Ganoderma boninense, the causal agent of basal stem rot disease of oil palm. A total of 600 isolates of spore producing and fast growing actinomycetes with different morphology were tested for their inhibitory effects on G. boninense mycelial growth on dual culture plates. About 13.5% of the isolates showed Percentage Inhibition of Radial Growth (PIRG) of more than 80% with 21 isolates exhibited observable abnormal growth of G. boninense. These 21 isolates were further tested using their culture filtrates in the form of liquid or powder (freeze-dried) for their effect towards G. boninense growth. Four isolates: AGA 043, AGA 048, AGA 347 and AGA 506 were highlighted for their ability to inhibit and exhibit potential metabolites against G. boninense. This study identified actinomycete strains with the ability to affect and inhibit the growth of G. boninense.

EFFECT OF Bacillus thuringiensis BASED-PRODUCTS ON RATS

Registration of pesticides with the National Pesticide Board must undergo laboratory testing for short-term and long-term health effects. Laboratory animals such as rats are purposely fed with high doses of the pesticide to cause toxic effects. The objectives of this study are to investigate the effect of Bacillus thuringiensis-based Bafog-1 (S) and Ecobac-1 (EC) against Sprague Dawley rats, to assess the toxicity of these Bt products. The acute oral and acute dermal toxicity studies were conducted according to OECD (Organisation for Economic Co-operation and Development) Guideline for Testing of Chemicals 425 (2001) and 402 (1987), respectively. The oral LD50 of Ecobac-1 (EC) and Bafog-1 (S) on female rats is more than 5000 mg kg-1, when administered orally with dose of 175 mg kg-1, respectively. Correspondingly, the LD50 for dermal administration of both Bt products is more than 2000 mg kg-1 for both male and female rats. There was no toxic symptom observed during the two weeks observation period in male and female rats. Post-mortem of the dermally treated animals at the end of the experiment did not show changes or adverse effect in the rats’ internal organs, indicating these two products are non-toxic to rats. Bt as an environmental-friendly microbial insecticide is generally not toxic to human, domestic animals and vertebrates.

NOVEL HIGH MOLECULAR WEIGHT POLYMERS BASED ON PALM OIL

Palm oil possesses, on average, about 1.8 double bonds per triglyceride. As a result of the relatively low level of unsaturation associated with palm oil, the ability to produce useful thermoset materials is limited. As a means to overcome this limitation, a novel palm oil-based monomer and polymer were produced. The monomer was produced by base-catalysed transesterification of palm oil with 2-(vinyloxy) ethanol. This monomer was subsequently polymerised using cationic polymerisation to produce a polymer with a number-average molecular weight of approximately 20 000 g mole-1. The cationic polymerisation process utilised enabled selective polymerisation through the vinyl ether groups. With this polymerisation process, the unsaturation derived from the palm oil was preserved and utilised for crosslinking. For example, the polymer produced was epoxidised and the epoxide groups subsequently ring-opened with methanol to produce a polymeric polyol. Due to the relatively higher number of hydroxyl groups per molecule associated with the palm oil-based polyvinyl ether polyol, tough, hard polyurethane coatings were produced that cured relatively quickly. Details related to monomer synthesis and characterisation, polymer synthesis and characterisation, polymer derivatisation and characterisation, and thermoset network production and characterisation are presented.

FORMULATION AND OPTIMISATION OF SPENT BLEACHING EARTH-BASED BIO ORGANIC FERTILISER

Spent bleaching earth (SBE) generated from the palm oil refinery is convertible into value-added products instead of being discarded as waste to landfills. An alternative approach is to develop SBE-based bio organic fertiliser through co-utilisation with other sources of biomass of contrasting nutrients properties. The feasibility of blending SBE with various forms of biomass – oil palm trunk (OPT), oil palm frond (OPF), empty fruit bunch (EFB) and chicken litter (CL) – in different mixing ratios was studied and its optimum ratio determined. The mixtures of SBE and various biomass at different mixing ratios were analysed for their macronutrient and micronutrient content, pH, organic carbon (OC), total nitrogen, carbon:nitrogen ratio (C:N) and organic matter (OM) content. The optimised blend of SBE:OPT:CL at the ratio of 1:1:0.5 exhibited sufficient nutrient contents (N: P2O5: K2O = 0.65:1.59:1.63) and good physicochemical properties (pH = 5.4, OM = 40% and C:N = 36:1) as a base material for bio organic fertiliser production. This optimum formulation was further enriched with urea (46% N), Christmas Island rock phosphate (CIRP, 25% P2O5) and muriate of potash (MOP, 66% K2O) to produce a bio organic fertiliser suitable for vegetable crops with desired nutrients N:P2O5:K2O ratio of 2:2:2.

PROPERTIES OF PARTICLEBOARD WITH OIL PALM TRUNK AS CORE LAYER IN COMPARISON TO THREE-LAYER RUBBERWOOD PARTICLEBOARD

Compaction ratio is highly dependent on the density of the wood materials used in the production of particleboard. Lower density wood materials will produce particleboard with higher compaction ratio and is believed to give better properties. The objective of this study was to evaluate the properties of threelayer particleboard made from rubberwood and oil palm trunk with different bulk density as the core layer, while the rubberwood fine particles served as surface layers for both types of particleboard. This study also investigated the effect of shelling ratios on the mechanical and physical properties of the threelayer particleboard. Melamine-fortified urea formaldehyde (UF) resin was used as the binder. The modulus of rupture (MOR), internal bond strength (IB) and thickness swelling (TS) of the particleboards were evaluated based on the Japanese Industrial Standard for particleboard (JIS A 5908:2003). The results showed that both species and shelling ratios are variables that influenced the mechanical and physical properties of the particleboard. Despite its lower compaction ratio, particleboard made from rubberwood alone had better strength properties and dimensional stability than particleboard made from a mixture of rubberwood and oil palm trunk.

PARTITION COEFFICIENT, WATER SOLUBILITY AND AQUATIC TOXICITY OF SHORT-CHAIN PALM FATTY ACIDS

The octanol/water partition coefficient (Pow) and water solubility (Sw) are important physico-chemical properties for an environmental risk assessment of a chemical substance, as well as ecotoxicity. It can be an indication of the extent to which the chemical might bioaccumulate in aquatic organisms. The log Pow of palm-based fatty acids was estimated using high performance liquid chromatography (HPLC) method, while the Sw value was determined using linear correlation between Sw and log Pow of reference compounds. The ecotoxicity of palm-based fatty acids was measured using test method OECD 203, Fish Acute Toxicity with common carp (Cyprinos carpio) as the test species. The short-chained C6 to C10 palm fatty acids were chosen for this study because they are generally toxic and can cause irritation to human and may have an adverse effect towards aquatic organisms. The log Pow values showed that both C6 and C8 fatty acids had low affinity towards aquatic organisms, but C10 fatty acid showed medium affinity towards these organisms. As for water solubility, C6 fatty acid had high affinity towards water, while both C8 and C10 fatty acids showed medium affinity towards water. The LC50 value of C6, C8 and C10 palm FAs are 7 mg litre-1, 7 mg litre-1 and 20 mg litre-1, respectively. It can be concluded that, the higher the carbon chain number of the fatty acid, the higher is the partition coefficient value, the water solubility decreases. The palm-based fatty acid can be considered as moderately toxic to aquatic organisms. These data can be used by the palm-based oleochemical manufacturers for product registration, preparation of product dossier or for marketing purposes.

TOCOPHEROL AND TOCOTRIENOL CONTENTS OF CHICKEN NUGGETS BLENDED WITH RED PALM OILS BEFORE AND AFTER FRYING

Tocopherols and tocotrienols content before and after frying in chicken nuggets blended with red palm oils NVRO, NVRO-100 and NVRO-50 was compared against the chicken fat treatment used as control. The lowest total tocopherols and tocotrienols content after frying was observed in control samples and the highest was in NVRO-100. Control samples showed significant increase of total tocopherols and tocotrienols from 34.32 ug g-1 before frying to 429.29 ug g-1 after frying due to oil uptake during frying where the cooking oil used was palm oil with inherent vitamin E precursors. The NVRO-50 showed significant decrease from 795.72 μg g-1 before frying to 690.87 μg g-1 after frying. Chicken nuggets blended with NVRO-100 were more heat stable followed by chicken nuggets blended with NVRO and NVRO-50. There was a significant loss of γ-T and δ-T in all samples after frying. This study showed the potential of utilising natural vitamin rich red palm oils as animal fat analogues in improving the nutritional quality of meat products.

STUDY TOWARD THE PREPARATION of AQUEOUS COMPATIBLE SHIKIMIC ACID IMPRINTED POLYMER

Shikimic acid is an important component in the production of several important drugs particularly the anti-influenza drug, Oseltamivir. Commercially, shikimic acid is extracted from the Chinese star anise or produced through the fermentation process by modified strain of E. coli. Regardless of the method of production, shikimic acid needs to be purified before it can be used for the intended purpose. Conventional method in the purification of shikimic acid usually involves the use of non-specific adsorbents that are less effective in isolating the shikimic acid. Molecularly imprinted polymer, being one of the latest adsorbents in separation science, offers an alternative technique that is more selective and specific than the conventional adsorption methods. This article is the exploratory work done to optimise the formulation for the preparation of molecular imprinted polymer for shikimic acid that is 100% compatible with aqueous systems. It emphasises particularly on the effects of various template: monomer: cross-linker ratios (TMX) on the performance of final polymer, including the preliminary evaluation results of the polymer performance.