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

Production and optimization of carboxymethyl cellulase and filter paperase of locally isolated Streptomyces lucitanus C5/2 under submerged fermentation of napier grass

Lignocellulosic biomass materials are known as a sustainable, renewable feedstock for biofuels production due to domestically abundant and low-production-cost derived from non-food sources. However, due to complex molecular structures of the cellulose, it becomes difficult to hydrolyze into fermentable sugar as the feedstock. The bioconversion of cellulose to fermentable sugar can be catalyzed by a group of enzymes known as cellulolytic enzymes, which is commonly produced by microorganisms (fungi, bacteria, and protozoa). Cellulolytic enzymes system mainly comprised of endoglucanase (carboxymethyl cellulase), exoglucanase, and β- glucosidase enzymes which react together to perform complete hydrolysis process. Grass species are one of cheap lignocellulosic biomass that can be used as energy source in many bioprocesses and industrial applications. Napier grass, scientific name Pennisetum purpureum sp is one of the potential carbon sources, which can be utilized as a substrate for the production of bio-product. The potential of Napier grass as a fermentation substrate was investigated throughout this study. Isolation and identification of the cellulolytic producing bacteria were carried out by initially searching the bacteria from various environmental sources (cattle waste compost, decayed wood and ponds). The cellulolytic enzymes biosynthesis by the selected bacteria isolate using Napier grass as a substrate in submerged fermentation was carried out in batch cultivation using 250 mL shake-flask. The investigations were followed by statistical optimization using response surface methodology (RSM) approach to obtain the optimized cultural conditions and medium composition for maximum activities of carboxymethyl cellulase (CMCase) and filter paperase (FPase). For the assessment of crude enzyme produced, enzymatic hydrolysis of Napier grass was performed by using untreated and treated (1.4M H2SO4 and 7% NaOH) Napier grass to investigate the total reducing sugar production. A total of twenty- five (25) bacterial isolates were grown on the selective media and only six (6) bacterial isolates showed positive results by exhibiting clear zone on carboxymethyl cellulose (CMC) agar plates, which indicate the enzymes production. The C5/2 isolate was selected as the best cellulolytic enzymes producer due to the highest enzyme activities obtained during the quantitative screening and molecularly identified as Streptomyces lucitanus by 16S rDNA sequencing. The optimum values of the fermentation parameters for CMCase and FPase biosynthesis based on the statistical optimization was determined at initial pH of 7.8, agitation speed 170 rpm, inoculum size 19.7% (v/v) and Napier grass concentration 4.30% (w/v) with maximum activities 7.362 U/mL and 2.895 U/mL, respectively which were close to the predicted values. The production of CMCase and FPase shows improvement, 66% and 30%, respectively by application of the optimum values of parameters during the cultivation. The total reducing sugar produced from enzymatic hydrolysis by using treated Napier grass (1.4M H2SO4; 6.541 mg/mL, 7% NaOH; 27.449 mg/mL) as a substrate is higher compared to the untreated Napier grass (1.776 mg/mL). It can be concluded that the newly isolated S. lucitanus C5/2 was able to produce appropriate amount of CMCase and FPase using raw Napier grass as the substrate and significantly improved enzyme activities after statistical optimization by RSM was employed. In addition, the crude cellulolytic enzyme produced by S. lucitanus C5/2 has proven to possess potential application in the hydrolysis of lignocellulosic biomass as Napier grass was been used for production of fermentable sugar. From this investigation, Napier grass shows a good fermentation substrate that it can be fully utilized for the production of bio-product

Human resource management practices and employee's turnover intention in the manufacturing industry in Malaysia

The main objective of this study is to examine the influence of Human Resource Management (HRM) practices (compensation and benefits, recruitment and selection and work-life policies) on employee's turnover intention. A survey questionnaire was sent and collected from 60 respondents who worked in the Manufacturing Industry in Malaysia. The results showed that the main factor that influences turnover intention of the employees was compensation and benefits. Hence, manufacturing firms ought to put extra efforts in this aspect in order to retain talents and minimize turnover rate of its workforce. Recruitment and selection and work-life policies were found to be not significant in predicting employee’s turnover intention

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

3.5 GHZ Vivaldi Antennas:A Comprehensive Parametric Analysis For Unleashing 5G Communication Technology

In this study, we discuss the design and testing of a Vivaldi antenna operating at 3.5 GHz, which is well-suited for mobile mid-band 5G connection. CST Microwave Studio software was used to simulate and evaluate the suggested antenna design, which was printed utilising state-of-the-art 3D printing processes and materials (polylactic acid (PLA) and FR-4 circuit board material). The measured results show that the antenna has a reflection frequency of 3.51 GHz and a gain of -23.695 dB. Parametric analysis was carried out to examine the relationship between antenna performance and design parameters, with special focus on the separation between the antenna and the PLA material in the middle of the spherical construction. The Vivaldi antenna is an attractive choice for 5G mid-band applications because of its wideband features, ease of manufacture using typical industrial processes, and simplicity of impedance matching to the feeding line using microstrip line modellin