Strength Performance and Microstructure Characteristic of Naturally-Bonded Fiberboard Composite from Malaysian Bamboo(Bambusa vulgaris)

This study investigated the mechanical properties and microstructural characteristics of fiberboard composite produced by naturally-bonded Malaysian bamboo fiber(Bambusa vulgaris).The components that obtained through soda pulping of bamboo culms such as fiber and black liquor,were used for the preparation of high-density fibreboard composite at two target densities of 850 and 950 kg/m^(3).The bamboo fiberboard composite(BFC)were then produced at 200°C and two pressing parameters of 125 and 175 s/mm.The mechanical properties,e.g.,flexural strength and internal bonding(IB)of BFC samples were evaluated according to BS EN 310:1993 and BS EN 319:1993,respectively.It was found that the mechanical performance of the composite with 850 kg/m^(3)density was significantly higher than 950 kg/m^(3)ones,especially for the samples with 125 s/mm pressing parameter.Microstructure characteristic of the BFC samples illustrated that the fiber linkages were cracked in the composites with higher density,e.g.,the composite with the density of 950 kg/m^(3)and also black liquor were slightly degraded at longer pressing time,which led to the reduction in mechanical properties,especially in IB strength.

Evaluation of Inherited Resistance Genes of Bacterial Leaf Blight, Blast and Drought Tolerance in Improved Rice Lines

Improved rice lines were developed frome three parents with the resistance or tolerance to bacterial leaf blight,blast and drought stress,respectively,using single-,double-and three-way crosses.The improved lines were assessed for agro-morphological and yield traits under non-drought stress(NS)and reproductive-stage drought stress(RS)treatments.The mean comparison of traits measured between parent plants and progenies(improved lines)were similar,and there were significant and non-significant differences among the parents and improved lines(genotypes)under NS and RS.Smilarly,there was significant and non-significant differences in the interaction among both parent varieties and improved lines for NS and RS.Cluster and 3D-model of principal component analysis did not generate categorical clusters according to crossing methods,and there were no exclusive crossing method inclined variations under the treatments.The improved lines were high-yielding,disease resistant,and drought-tolerant compared with their parents.All the crossing methods were good for this crop improvement program without preference to any,despite the number of genes introgressed.

Influence of Agitation Rate on the Growth of MD2 Pineapple Protocorm-Like Bodies and Shoots in Liquid-Shake Culture

The present study was conducted to investigate the effect of agitation rate on the increase in fresh weight of MD2 pineapple protocorm-like bodies (PLBs) and shoots cultured in liquid medium. PLBs were cultured in 250 ml Erlenmeyer flasks (7 g per flask) containing MS medium and plant growth regulators (1.5 mg/L 6-Benzylaminopurine, BAP and 0.2 mg/L 1-Naphthaleneacetic acid, NAA). The orbital shaker was set at speeds of 50, 80, 100, 120, and 150 rpm. After 40 days, the cultures shaken at 80 rpm showed the highest fresh weight and the highest number of shoots at 76 g and 41 shoots, respectively. A comparative study of agitation found that 80 rpm was the best speed which enhanced both PLB and shoot formation. The findings in the present study would be helpful in setting up large-scale in vitro mass propagation of MD2 pineapple.

Development of Starfruit Simple Sequence Repeat (SSR) Using Next Generation Sequencing

Starfruit (Averrhoa carambola L.) is an important fruit for Malaysian export and great attention has been made to improve starfruit fruit quality at Malaysian Agricultural Research and Development Institute (MARDI). The current study used next generation sequencing (NGS) technologies to develop starfruit simple sequence repeat (SSR) from 2 varieties namely B11 and B17 using Illumina HiSeq. The pre-processed reads were de novo assembled to generate approximately 75,000 and 74,000 scaffolds respectively. Total genome size for B11 and B17 were around 345 Mbp and 342 Mbp based on K-mer distribution analysis. In-silico microsatellite mining of each variety has identified more than 17,000 SSR in B11 and B17 respectively. Dinucleotides were the most abundant, accounting for more than 70% of all SSR and repeat motif GA (49%) was most common. A total of 239 SSR primer pairs were designed from contigs larger than 350 nucleotides and tested for amplification. The 30 polymorphic SSRs were used to DNA fingerprint of 12 starfruit hybrids. Polymorphism information content (PIC) ranged from 0.1411 to 0.6838, with an average of 0.3919. The Unweighted Pair-Group Method for Arithmetic Averages (UPGMA) dendrogram clustered 12 starfruit accessions into 2 groups.

Towards Biorefinery Production of Microalgal Biofuels and Bioproducts: Production of Acetic Acid from the Fermentation of <i>Chlorella</i>sp. and <i>Tetraselmis suecica</i>Hydrolysates

Successful commercialization of microalgal bio-industry requires the design of an integrated microalgal biorefinery system that facilitates the co-production of biofuels, high-value products and industrial chemicals from the biomass. In this study, we investigated the use of sugar hydrolysate obtained from enzymatic saccharification of microalgal biomass (Chlorella sp. and T. suecica) as fermentation feedstock to produce industrially important chemicals, in particular acetic acid and butyric acid. By using hydrolysate with low sugar content as substrate for the anaerobic fermentation (1.5 - 2.4 g/L), we were able to prevent the bacterium C. saccharoperbutylacetonicum from activating its solventogenesis pathway. As a result, the fermentation process generated a product stream that was dominated by organic acids (acetic acid and butyric acid) rather than solvents (butanol, ethanol and acetone). Acetic acid constituted up to 92 wt% of Chlorella’s fermentation products and 80 wt% of T. suecica’s fermentation products. For T. suecica, the fermentation consumed almost all of the sugar available in the hydrolysate (up to 92% of initial sugar) and produced a reasonable yield of fermentation products (0.08 g fermentation products/g sugar). The Gompertz equation was successfully used to predict the formation kinetics of acetic acid and other fermentation products across both species. The results in the study demonstrate the production of industrially important chemicals, such as acetic acid and butyric acid, from the fermentation of microalgal sugar. The process described in the study can potentially be used as a value-adding step to generate biochemicals from cell debris in an integrated microalgal biorefinery system.

Callus Induction of Young Leaf Coconut cv. MATAG with Combination of 2,4-Dichlorophenoxyacetic Acid (2,4-D), α-Naphthalene Acetic Acid (NAA) and Benzyl Amino Purin (BAP)

This research was to study in vitro callus induction in Coconut cv MATAG from young leaf explants. Young leaf segments from mature coconut were cultured on Y3 medium supplemented with different concentrations of 2,4-D and a combination of NAA and BAP. Each of these plant growth regulators (PGR) gives different responses toward callus formation, the percentage of explants producing callus, the percentage of callus proliferation, and the morphology of callus. A series of different concentrations were used for 2,4-D (1, 5, 10, 20, 40, 60, 100 mg/L), NAA (1, 3, 5 mg/L) and BAP (1, 3, 5 mg/L) respectively. The range of days of callus formation using 2,4-D treatments is 7 - 12 months, while the 2,4-D combined with NAA is recorded at 2 - 5 months. Despite the variety of different months between these plant growth regulators for callus formation, the percentages of explants producing callus and callus proliferation are different. The highest percentage of explants producing callus (2.9%) was observed at 2,4-D (40 mg/mL), followed by 2.7% at 2,4-D (10.0 mg/mL) with NAA (1 mg/mL). At a concentration of 100 mg/mL of 2,4-D, the highest percentage of callus proliferation was found, as well.

Chemical profiling of Curcuma aeruginosa Roxb. rhizome using different techniques of solvent extraction

Objective:To investigate the possible phytochemical constituents of Curcuma aeruginosa Roxb.(C. aeruginosa) rhizome using two different techniques of direct solvent extraction. Methods: Two different techniques of direct solvent extractions, i.e. methyl tert-butyl ether(MTBE) extraction and two-phase methanol/chloroform(M/C) system, were used in this study. The analysis of the phytochemical constituents in MTBE and M/C extracts was performed using gas chromatography-mass spectrometry/mass spectrometry. The mass spectra of the compounds was matched with the NIST 08 mass spectral library. Results: The present study revealed that the extraction using two-phase M/C have resulted in higher metabolite coverage compared to the extraction with MTBE. Direct solvent extraction using MTBE revealed the presence of 27 compounds; whereas, M/C allowed the extraction of 18 and 36 compounds in polar(methanol) and nonpolar(chloroform) fractions respectively. The major compounds detected in the MTBE extract that based on the peak area percentage were methenolone(16.64%), cycloisolongifolene, 8,9-dehydro-9-formyl-(15.93%), labd-13-en-15-oic acid,8,12-epoxy-12-hydroxy-γ-lactone(10.77%), propiolic acid, 3-(1-hydroxy)-2 isopropyl-1,5-methylcyclohexyl)(7.84%), 4-oxo-β-isodamascol(5.17%), velleral(3.11%) and Z-α-farnesene(2.00%). The most prevailing major compounds identified in the polar fraction of the M/C extraction were α-D glucopyranoside, 1,3,4,6 tetrakis-O-(TMS)(trimethylsilyl)-β-D-fructofuranosyl 2,3,4,6-tetrakis-O-(TMS)-(38.08%), d-glucose, 2,3,4,5,6-pentakis-O-(TMS)-, O-methyloxime(14.61%), D-fructose, 1,3,4,5,6-pentakis-O-(TMS)-, O-methyloxime(5.28%), isocitric acid(TMS)(3.06%), oxalic acid, bis(TMS) ester(2.96%), hexadecanoic acid, TMS ester(2.16%), citric acid, ethyl ester, tri-TMS(1.91%) and butanedioic acid, [(TMS) oxy]-, bis(TMS) ester(1.14%); whereas in the nonpolar extract, among the major compounds detected were cycloisolongifolene, 8, 9-dehydro-9-formyl(15.70%), propiolic acid, 3-(1-hydroxy-2-isopropyl-5-methylcyclohexyl)(11.09%), stearic acid, TMS ester(2.78%), hexadecanoic acid, TMS ester(2.33%), oleic acid, TMS ester(1.62%), curzerene(1.56%); Z-α-farnesene(1.52%), germacrone(1.41%) and β-elemene(1.33%). Conclusions: It was evident from the results that C. aeruginosa rhizome extracted using two different techniques of solvent extractions(MTBE and M/C) contained various chemical classes of compounds including terpenoids, sterols, organic acids, fatty acids and sugars. Different methods of extraction have led to different compounds extraction for C. aeruginosa rhizome. The results also indicated that the plant was a source of phytochemical importance.

Discovery of Simple Sequence Repeat Markers through Transcriptome Analysis of Baccaurea motleyana

Baccaurea motleyana(rambai)is underutilized fruits that are native to Malaysia,Indonesia and Thailand.In this study,a total of 54,779 unigenes identified from rambai transcriptome were used for simple sequence repeat(SSR)analysis by MIcroSAtellite(MISA).A total of 20,420 SSRs were found to be distributed within 37.27%of the total number of unigenes.Mononucleotide repeats represented the main type,accounting for 64.04%,followed by trinucleotide repeats(20.28%)and dinucleotide repeats(19.94%).Gene annotation to seven databases has a success ratio of 68.53%(National Center for Biotechnology Information(NCBI)protein sequences),53.68%(NCBI nucleotide sequences),27.43%(Kyoto Encyclopedia of Genes and Genome Ortholog),56.0%(SwissProt),52.44%(Protein family),53.99%(Gene Ontology)and 26.44%(Kluster of Orthologous Group).Further rambai SSRs were randomly selected and validated to B.motleyana(rambai),B.macrocarpa(tampoi),B.polyneura(jentik-jentik),B.ramiflora(pupor)and B.scortechinii(setambun).