S. Chandran

Pigment identification and antioxidant properties of red dragon fruit ( Hylocereus polyrhizus )

The aim of this study was to identify pigments present in the red dragon fruit ( Hylocereus polyrhizus ) and to further investigate the antioxidant properties in this fruit. Pigment was identified using the High Performance Liquid Chromatography (HPLC) and results confirmed the presence of betanin in sample at a retention time of 11.5 min which corresponded to the retention time of the betanin standard used. In the antioxidant properties determination, there were 86.10 mg of total polyphenolic compound in 0.50 g of dried dragon fruit extract using the total polyphenol assay which expresses gallic acid as equivalent. The reducing power assay further confirmed the antioxidant activity present in dragon fruit where the reducing capability increased from 0.18 to 2.37 with the increase of dry weight sample from 0.03 to 0.5 g. The Vanillin-HCl assay which measures the amount of condensed tannin showed that the dried dragon fruit sample had an equivalent of 2.30 mg catechin/g. The DPPH• radical scavenging activity determination showed that the effective concentration (EC50) for dragon fruit was 2.90 mM vitamin C equivalents/g dried extract.

Biodiesel production from waste soybean oil biomass as renewable energy and environmental recycled process

Alternative fuel is currently an important issue all over the world due to the efforts on reducing global warming which is contributed by the combustion of petroleum or petrol diesel. Biodiesel is non-toxic, biodegradable, produced from renewable sources and contributes a minimal amount of net green house gases, such as CO2, SO2 and NO emissions to the atmosphere. The study was carried out to produce biodiesel from waste/recycled oils to reduce the cost of biodiesel, waste and pollution. Some important variables such as volumetric ratio, types of reactants and catalytic activities were selected to obtain a high quality biodiesel fuel within the specifications of the American Standard for Biodiesel Testing Method (ASTM D 6751) and European Norm (EN 14214). The highest biodiesel yield was obtained (71.2%) under the conditions of 1:1 volumetric oil-to-methanol weight ratio, 0.5% NaOH catalyst at 50°C reaction temperature and 320 rpm stirring speed. The results showed that biodiesel produced from different oil to methanol ratios, alcohol types and shaking time exhibited considerable differences. There was also a considerable difference of biodiesel yield produced by using methanol, ethanol and 1butanol. The biodiesel yield increased in the order of 1-butanol < ethanol <methanol. There was a little difference in viscosity, acid value and chemical elements (Fe, Mg, Ca, Na, P etc.) at different parameters. The research showed that biodiesel obtained under optimum conditions from completely waste oil was of good quality and could be used as a diesel fuel which is considered as potential use of waste cooking oil. In addition, bioenergy could be renewed and environmental recycling process could be maintained potentially using waste soybean cooking oil.

Multi-gene region phylogenetic analyses suggest reticulate evolution and a clade of Australian origin among paleotropical woody bamboos (Poaceae: Bambusoideae: Bambuseae)

The paleotropical woody bamboo subtribe Bambusinae has not been satisfactorily circumscribed and remains a major taxonomic problem. Genera such as Holttumochloa, Mullerochloa and Temburongia have not been confidently assigned to this subtribe. The phylogenetic relationships among genera hitherto placed in or near the Bambusinae, together with the related subtribes Racemobambosinae and Melocanninae, were investigated using three chloroplast DNA markers (rps16-trnQ, trnC-rpoB and trnD-T intergenic spacers) and a nuclear DNA marker (granule-bound starch synthase I, GBSSI) for a sample of 51 ingroup species and 2 outgroup species. Phylogenetic analyses revealed four distinct lineages among the members of the currently recognized Bambusinae: (1) the Bambusa-Dendrocalamus-Gigantochloa (BDG) complex, (2) the Holttumochloa-Kinabaluchloa clade, (3) the Dinochloa-Mullerochloa-Neololeba-Sphaerobambos (DMNS) clade and (4) Temburongia simplex. The BDG complex, which comprises the core of the Bambusinae, appears to have a complex evolutionary history as indicated by incongruence between the cpDNA and the nuclear gene topologies. Introgressive hybridization and incomplete lineage sorting are possible underlying causes for this complexity. The distinction of the climbing-scrambling bamboo lineages from the core Bambusinae and Racemobambosinae suggests directions for investigating the possible existence of further subtribes with increased taxon and geographical sampling. Possible biogeographic scenarios associated with the Holttumochloa-Kinabaluchloa clade and the DMNS clade are discussed.

Isolation and Characterization of Senescence-Associated Ethylene Genes from Dendrobium Orchids

Pollination hastens senescence in most flowers via the regulation of the ethylene pathway. This phenomenon impacts on the lucrative orchid cut flower industry when attractive hybrids that are ethylenesensitive undergo rapid post-pollination induced senescence. Manipulation of ethylene-associated genes could overcome the problem in transgenic orchids if ethylene biosynthesis is suppressed or if the signal transduction pathway is confounded. While ACCO oxidase and ACC synthase have been acknowledged as key enzymes in the ethylene biosynthesis pathway, knowledge about ethylene receptors in orchids is still quite limited and often confusing. In our studies with Dendrobium Pompadour orchids, we have isolated the genes for ACC oxidase and ACC synthase as well as those for two ethylene receptors first characterized in Arabidopsis, namely ETR1and ERS1. Physiological studies have shown that within 24 h, pollinated Dendrobium flowers display an increase in ethylene production after Zuliana Razali , S. Chandran , Lee Ai Ling , A.N. Boyce , 327 Z. Xu et al. (eds.), Biotechnology and Sustainable Agriculture 2006 and Beyond, 327–332.

Extraction of Genomic DNA from roots and leaves of Hylocereus undatus

Since most DNA extraction protocols require young leaves to extract high quality DNA, seed germination is a useful in providing starting material for DNA extraction. In the case of Hylocereus undatus, since the fruit contains thousand of seeds, seed germination can be used to produce material in abundance for DNA extraction by harvesting the seeds from the mature fruit. In this study, sodium bisulfite, sodium sarkosyl, and sorbitol were added to the DNA isolation buffer. Sodium bisulphite prevents oxidation of phenolic compounds, whereas sodium sarkosyl precipitates high levels of polysaccharides. The use of this modified DNA extraction method resulted in high-yield DNA. The result was reproducible and the DNA can be stored in TE buffer at -20 °C for months without degradation, can be digested using BamH1, and can then be used for construction of a library.

Construction of Genomic Library of Chokanan Mango (Mangifera indica)

Chokanan mango (Mangifera indica) is special for its attractive aroma and sweet taste. More importantly, it exhibits high tolerance against adverse weather conditions during fruiting and is resistant against the attack of fruit fly due to its thick peel characteristic. A bacteriophage lambda DNA genomic library is under construction to establish a database of Chokanan mango. The improvement on the quality of the extracted total DNA was achieved through the optimization of leaf harvesting stage and modification on the CTAB DNA extraction procedure. Fully expanded, softened and purplish coloured leaf proved to yield good quality DNA while the addition of polyvinylpyrrolidone (PVP), β-mercaptoethanol and high salt washing was effective in the removal of polyphenolic compounds and polysaccharides. Insert DNA was digested with BamHI while Lambda FIX II vector was used as vector. The completion of the genomic library will serve as a database to consolidate a genetic map of Chokanan mango, which will enable gene discovery, studies of gene functions, and comparative genomics with other plant species.