SURFACE MORPHOLOGY AND CHEMICAL COMPOSITION OF NAPIER GRASS FIBERS (Morfologi Permukaan dan Komposisi Kimia Gentian Rumput Napier)

Abstract A cellulosic component of Napier grass has high potential for the ethanol production. The presence of hemicelluloses, lignin and cellulose in Napier grass fiber can affect the ethanol production. The aim of this study is analyzed the effect of different pretreatment condition (2% of acetic acid and 2% of sodium hydroxide) on the chemical composition and observe the fiber surface morphology of the Napier grass fibers. The fiber surface morphology was observed using Scanning Electrone Microscope (SEM). The result of different pretreatment condition showed that 2% of acetic acid treatment have the highest percentage of cellulose followed by 2% of sodium hydroxide treatment and untreated sample. The hemicellulose content is reduced when treated with acid and alkali. Based on the fiber morphology characterization, acid and alkali pretreatment condition showed that the surface impurities on the fiber were removed. This study suggested that the acid and alkali treatment of Napier grass fibers has a potential to enhance the ethanol production because it can reduce the hemicellulose content. Keywords: Cellulose, Napier grass fiber composition, Pretreatment Abstrak Komponen selulosa dalam rumput Napier mempunyai potensi yang tinggi untuk menghasilkan etanol. Kehadiran hemiselulosa, lignin dan selulosa dalam gentian rumput Napier boleh memberi kesan kepada penghasilan etanol. Objektif kajian ini adalah untuk menganalisa komposisi kimia rumput Napier dalam keadaan pra-rawatan yang berbeza (2% asid asetik dan 2% natrium hidroksida) dan untuk melihat pencirian gentian serat rumput Napier berdasarkan pra-rawatan yang berbeza. Morfologi permukaan gentian dilihat menggunakan Mikroskop Elektron Pengimbas. Keputusan analisa menunjukkan bahawa peratusan selulosa berdasarkan 2% rawatan asid asetik adalah paling tinggi, diikuti gentian yang dirawat dengan 2% natrium hidroksida dan sampel gentian yang tidak dirawat. Kandungan hemiselulosa berkurangan apabila dirawat dengan asid dan alkali. Berdasarkan pencirian morfologi, gentian rumput Napier yang dirawat dengan asid dan alkali mempunyai morfologi permukaan yang lebih licin dan mempunyai banyak ruang di antara gentian. Kajian ini mencadangkan bahawa rawatan asid dan alkali mempunyai potensi untuk menambahkan penghasilan etanol disebabkan berlakunya pengurangan kandungan hemiselulosa

Carboxymethyl-cellulase and filter-paperase activities of napier grass fermentation by new bacterial isolates

Cellulosic biomass is a renewable and most abundant resource with high potential for bioconversion to biofuels. It can be degraded by cellulase produced by cellulolytic producing bacteria. Proximately, three different types of cellulase needed for effective enzymatic hydrolysis; endoglucanase (CMCase), exocellobiohydrolase and β -glucosidase. Total cellulase activity can be determined by measuring reducing sugar derived from filter paper (FPase) while endoglucanase (CMCase) can be determined by measure reducing sugar release from carboxymethyl- cellulose (CMC). In this study, the CMCase and FPase activities of new six isolates from different environments (compost: C5/1 and C5/2; ponds: L5/1, L6/2, and L6/5; and decayed wood: D6/1) were examined according methods recommended by the International Union of Pure and Applied Chemistry (IUPAC).The fermentation has been conducted for 4 days incubation period at 37°C and agitated at 150 rpm. Napier grass has been used as a substrate. As a result, the C5/2 exhibited the highest enzymes activities of CMCase and FPase, which were 2.205U/mL and 0.39U/mL, respectively