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Ho, L. S., Tan, B. A., Md Noh, N., A. Talib, S. S., Ithnin, N., Jeffery Daim, L. D., Eng Keong, T. O., and Mohd Yusof, H. (2015). "Preliminary analysis of lignocellulose content and monolignol composition of oil palm trunk from two different genetic backgrounds," BioRes. 10(4), 8194-8207.

Abstract

A preliminary investigation of chemical and lignin composition was conducted from samples of oil palm trunk of two different genetic backgrounds. A significant difference in percent (%) of standing palms was noted for the two different genetic backgrounds after 24 years of planting. Given that these palms were planted in neighboring fields, the objective of this preliminary study was to compare the chemical composition, as well as the lignin composition of the two palm varieties. When comparing the two populations, significant differences were observed in the structural carbohydrate composition and the lignin composition. This research constitutes the first reporting on the pyrolysis-gas chromatography-mass spectrometer analysis of oil palm trunk lignin composition.



Full Article

Preliminary Analysis of Lignocellulose Content and Monolignol Composition of Oil Palm Trunk from Two Different Genetic Backgrounds

Ho Li Sim,* Tan Bee Aik, Normahnani Md Noh, Siti Sarah A. Talib, Nalisha Ithnin, Leona Daniela Jeffery Daim, Tony Ooi Eng Keong, and Hirzun Mohd Yusof

A preliminary investigation of chemical and lignin composition was conducted from samples of oil palm trunk of two different genetic backgrounds. A significant difference in percent (%) of standing palms was noted for the two different genetic backgrounds after 24 years of planting. Given that these palms were planted in neighboring fields, the objective of this preliminary study was to compare the chemical composition, as well as the lignin composition of the two palm varieties. When comparing the two populations, significant differences were observed in the structural carbohydrate composition and the lignin composition. This research constitutes the first reporting on the pyrolysis-gas chromatography-mass spectrometer analysis of oil palm trunk lignin composition.

Keywords: Monolignol composition; Oil palm trunk; Py-GCMS; Chemical composition; Structural carbohydrate

Contact information: Sime Darby Technology Centre, 1st Floor Block B, UPM-MTDC Technology Centre III, UPM, 43400, Serdang, Selangor, Malaysia; *Corresponding author: ho.li.sim@simedarby.com

INTRODUCTION

Since it was first introduced to Malaysia in the early 1870’s, the oil palm has now been planted across 4.49 million hectares in Malaysia. This accounts for a production of about 17 million tonnes of palm oil and 2 million tonnes of palm kernel oil, making the nation one of the largest producers and exporters of palm oil in the world. Malaysia produces 11% of the world’s oils and fats and 27% of the export trade of oils and fats.

Despite being a major crop cultivated in Malaysia, little is known about the lignocellulose composition of oil palm trees. The dry matter of the plant is composed of lignocellulose, which is referred to as lignocellulosic biomass. It is the most abundantly available raw material in the world and has potential for application in biofuel production. Lignocelluloses are composed of carbohydrate polymers, i.e., cellulose and hemicelluloses (the structural carbohydrates), and aromatic polymers, i.e., lignin, which are tightly bound together (Sjöström 1993).

The deposition of lignin in many parts of a plant provides structural strength. The major component in the cell wall of the xylem is impermeable to water, which is a characteristic that allows the transport of water within the plant. In the context of plant pathology, lignin can provide a barrier to microbial attack, and hence it has important implications for the oil palm industry. Basal stem rot (BSR) disease is widely recognized as an important condition that the industry has been facing. The pathogenesis of BSR, which is caused by the Ganoderma boninense white rot fungi, is generally believed to cause the degradation of lignin in oil palm trees. White rot fungi are from a class of organisms that are capable of mineralizing lignin efficiently (Kirk and Cullen 1998). Different types of white rot fungi degrade lignin and carbohydrates in woody tissue at different rates and preferences. Some remove lignin more readily than carbohydrates, relative to the ratio of these two classes of biopolymers. The lignin component has been described as the rate-limiting factor in the biodegradation process (D’Souza et al. 1999). In addition, Paterson (2007) mentioned that lignin biodegradation is possibly the most influential part of the disease process. Guaiacyl (G) units of lignin are known to be more resistant to degradation than syringyl (S) units (Hatakka 2005). Studies show that the physiological condition of the plant is as important as the enzymes expressed by the fungi. Many studies have focused on the chemical composition of the oil palm trunk for its potential application in pulp processes, alternative sources of compressed wood, and/or other economic utilization (Khalil et al. 2007; Sitti Fatimah et al. 2012; Sulaiman et al. 2012; Lai and Idris 2013).

In 2013, while breeders were carrying out a standard census for progeny trials, two neighboring trials were found to have significantly different numbers of standing palms after 24 years. These progeny trials, namely the Dumpy AVROS (PT93) and Tanzanian (PT95), were established in 1989 by the Klanang Bharu Division, Sime Darby Plantation, Selangor, Malaysia. In 2013, at 24 years of age, the percentage of standing palms was 51.38% and 88.88% for the PT93 and PT95 backgrounds, respectively. Based on this observation, it was of potential interest to find out the contributing factors that influence the difference in the number of standing palms, given that these palms were grown in the same environment. The collapse of the palms was possibly attributable to the weakening in physical structure of the oil palm trunk. Therefore, it is postulated that: (i) the natural physical strength can be influenced by genetics and/or agronomy practices (Stackpole et al. 2011), or (ii) it may be caused by disease, such as BSR (Ariffin et al. 2000). In both cases, the condition of the physical structure is reflected in the composition of the trunks (Winandy and Rowell 2005). Hence, the objective of this study is to conduct a preliminary comparison of the chemical composition of oil palm trunks from two different genetic backgrounds.

EXPERIMENTAL

Selection of Oil Palm Trees

Oil palm trees of Tanzania (PT95) and Dumpy AVROS (PT93) lines, planted in neighboring fields located in Klanang Bharu Division, Sime Darby Plantation, Selangor, Malaysia, were selected for use in this study. For each background, two predetermined healthy palms were selected for each trial.

Samples Extraction and Preparation

Tissue samples from the oil palm trunks were harvested from approximately one foot above the ground. The samples were extracted using a motor drill at four points as shown by the cross configuration (  ) in Fig. 2. Samples were extracted to the depth of approximately 20 to 24 cm radius. Samples from all points of the individual oil palm trunk were mixed, homogenized, and oven-dried to a constant weight at 60 °C. The dried tissues were then ground into fine particles and used for further analysis.