Category Archives: In Press

MOLECULAR CLONING OF Ganoderma boninense HOG1-TYPE MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) cDNA AND TRANSCRIPTIONAL RESPONSE TO SALINITY STRESS

The white rot fungus, Ganoderma boninense is the main causal agent of basal stem rot disease in oil palm plantations in South-east Asia especially Malaysia and Indonesia. Despite serious attention given the fungus, knowledge on the pathogen-oil palm interaction especially from the molecular and biochemical aspects is still inadequate to provide a better understanding on the disease. In this study, an 1161 bp of full-length cDNA encoding a Hog1-type MAPK was obtained from G. boninense. Based on the multiple sequence alignment, the conserved motif TGY (novel activation loop motif), N-terminal-conserved domain, HRDLKPN and the C-terminal-conserved domain, TRWYRAP were found in G. boninense Hog1 MAPK. Results of salinity stress assay indicated that G. boninense growth was slower on media containing 0.4 M NaCl and could not survive on media containing 1.0 M NaCl. Real-time quantitative PCR analysis showed that GbHog1 MAPK transcript was consistently upregulated to nearly 4.0 folds after 2 hr of exposure to 0.4 M NaCl. This study provides a preliminary understanding on the involvement of GbHog1 MAPK in salinity stress response. Identification of GbHog1 MAPK could also lead to understanding of the involvement of G. boninense MAPK in pathogenicity as reported in several plant pathogenic fungi.

CARBONISATION-ACTIVATION OF OIL PALM KERNEL SHELL TO PRODUCE ACTIVATED CARBON AND METHYLENE BLUE ADSORPTION KINETICS

The carbonisation-activation system was developed to produce activated carbon from oil palm kernel shell (OPKS). The OPKS was carbonised at 500°C for 3 hr in an electric vertical reactor followed by steaming at 700°C for another 3 hr in the same reactor. The process showed significant results with a high activated carbon yield of 32%, high fixed carbon content of 88.6% with Brunauer-Emmett-Teller (BET) surface area of 305.67 m2 g-1. The OPKS-activated carbon was further tested to remove methylene blue. It could adsorb up to 99.7% of methylene blue using only 0.6 g litre-1 dosage of OPKS-activated carbon, for 24 hr of treatment time. The results have been correlated in the Freundlich isotherm which was well fitted to the experimental data over the methylene blue experimental concentration range with correlation coefficients of R2=0.992.

BIOCHEMICAL PROFILE OF BACTERISED CALLI AND EMBRYOGENIC CALLI OF OIL PALM (Elaeis guineensis Jacq.)

Recent approaches have been made with regard to successful association of in vitro oil palm materials and diazotrophs. But, no biochemical study was revealed to explain possible relationship between the diazotroph and in vitro oil palm plant proliferation processes. In this study, calli and embryogenic calli of oil palm (Elaeis guineensis Jacq.) were treated with different inoculums of Herbaspirillum seropedicae strain Z78 (ATCC 35893) namely, sonicated cells and pellet cells. Treated oil palm tissues were observed for total amino acids, proteins, phenolics and sugar levels which were extracted and quantified every 10 days throughout 60 days of culturing. Results reveal a reduction of total sugar levels, increment of phenolics, amino acids and protein contents of bacterised calli with Z78 pellet cells which can explain rapid progression of embryogenic development. High content of phenolic compounds, sugar levels with the reduction of amino acids and proteins in bacterised embryogenic calli with Z78 sonicated cells would elucidate accelerated embryo regeneration and maturation. These results provide a novel explanation for biochemical profiles of bacterised oil palm calli and embryogenic calli. With the understanding of biochemical patterns, this can act as a guide for further in-depth study on in vitro plant cells-microbe interactions.

PHYSICAL AND CHEMICAL CHARACTERISTICS OF PALM OIL-BASED SOLID FRACTIONS WITH MORE THAN 20% OF TRIPALMITOYLGLYCEROL FROM MALAYSIAN FRACTIONATION PLANTS

The varied triacylglycerol composition of palm oil-based solid fractions (POSF) gives unique characteristics to its fractions. The potential to develop specific fractions for specific functionalities is very vital to the Malaysian palm oil industry in order to widen the usage of POSF for food formulations. Fractions with higher amounts of trisaturated triacylglycerols are excellent structural fats for food formulations. This compilation was directed towards obtaining the primary information on the characteristics of POSF available in Malaysia containing more than 20% of tripalmitoyl-glycerol. This information will be vital in guiding food formulators on the wide options of structural fats available in Malaysia. Commercially available POSF were collected and characterised. Their triacylglycerol composition, fatty acid composition, iodine value, dropping point, and solid fat content were determined. The results showed that the characteristics of the POSF were greatly influenced by the amount of tripalmitoyl-glycerol (PPP) present in the fractions. The amount of PPP had a substantial impact on the dropping point and the solid fat content profile. Hence, fractions were categorised according to their percentage of PPP to provide groupings with specific physical and chemical characteristics. The percentage of PPP in Group PPP 1 was 20% to 30%, PPP 2 was 40% to 50%, PPP 3 was 55% to 60%, PPP 4 was 62% to 63% and PPP 5 was 67% to 68%. The range of dropping points recorded for PPP 1 was 54°C to 56°C, PPP 2 was 59°C to 60°C, PPP 3 was 61°C to 62°C PPP 4 was 62.2°C to 62.4°C and PPP 5 was 63.1°C to 63.7°C. The range of solid fat content at 30°C recorded for PPP 1 was 44% to 54%, PPP 2 was 78% to 82%, PPP 3 was 86% to 89%, PPP 4 was 90% to 91% and PPP 5 was 91% to 93%. This compilation shows the extensive range of POSF which are able to provide a specific functionality to facilitate their specialised application in food formulations that are commercially available in Malaysia.

SCALE DEPOSITS FROM PALM OIL MILL EFFLUENT (POME) TREATMENT AND VARIOUS OTHER INDUSTRIES: A DEVELOPMENTAL REVIEW

The palm oil mill effluent (POME) treatment process is exposed to the formation of crystal-like deposits where their accumulation could create a significant threat to achieving an efficient POME treatment. This article reviewed similar occurrences in other industries, discussed factors influencing the crystal formation and suggested possible solutions to be applied in the oil palm industry. From the review, it was found that crystal deposits have always been a nuisance and sometimes a significant threat to similar industries such as industrial, agricultural and municipal wastewater treatment facilities. Other industries where there is a handling process of certain type of fluids such as heat transfer and oil reservoir drilling fluids also faces similar problems. The article also presented the spectrum of methods for mitigation and removal of the crystal formed. For many cases, nutrient recovery through struvite precipitation has become attractive as it not only reduces crystal growth but at the same time prevents excessive nutrients discharge to the environment. Further exploitation of the recovered struvite as a fertiliser source could possibly generate additional income to the oil palm industry.

ADSORPTION OF NPK FERTILISER AND HUMIC ACID ON PALM KERNEL SHELL BIOCHAR

To date, no study has been reported on adsorption capacity (Qe) of palm kernel shell (PKS) biochar for plant nutrients NO3 -, NH 4 + , PO4 3- and K+ (NPK) while most biochar adsorption investigations have not considered the effect of dissolved soil organic matter e.g. humic acid (HA). In our study, we produced PKS biochar at different temperatures and holding times and conducted sorption experiments with a commercial NPK fertiliser and HA. HA-coated PKS biochar was investigated for its capability in adsorbing NPK. Equilibrium adsorption experiments showed that NH 4 + and HA were adsorbed with no effect for NO3 – and PO4 3-, while K+ concentration in solution increased exponentially over time. The highest Qe of NH 4 + (0.522 ± 0.036 mg g-1; p<0.05) and that of HA (0.649 ± 0.073 mg g-1) were observed for 400°C PKS biochar. The best-fitted HA sorption with Freundlich isotherm (R2 = 0.904) reveals a heterogeneous surface and arguably multiple layer sorption of HA. A 55.9% reduction in Qe of NH4 + for HA-coated 600°C PKS biochar suggests that performances observed in the laboratory cannot be directly extrapolated to the field. Furthermore, a realistic mechanistic understanding of PKS biochar sorption efficiency on NPK associated with soil matrix components such as humic substances, microorganisms and colloidal clay particles is essential.