Tar-free and benzo[a]pyrene-free hydrothermal liquefaction of bamboo and antibacterial property of recovered vinegar

Bamboo, which was treated using superheated steam controlled at a low temperature range, gave tar-free and benzo[a]pyrene-free vinegar. The vinegar’s selective antibacterial activity against Staphylococcus aureus concerned with the atopic dermatitis and Bacillus cereus causing food poisoning in humans was confirmed, while no effect was found against Escherichia coli and Bacillus subtilis as being indigenous bacteria in natural environments

Tar-free and Benzo[a]pyrene-free Hydrothermal Liquefaction of Bamboo and Antibacterial Property of Recovered Vinegar

Bamboo, which was treated using superheated steam controlled at a low temperature range, gave tar-free and benzo[a]pyrene-free vinegar. The vinegar’s selective antibacterial activity against Staphylococcus aureus concerned with the atopic dermatitis and Bacillus cereus causing food poisoning in humans was confirmed, while no effect was found against Escherichia coli and Bacillus subtilis as being indigenous bacteria in natural environments

Short Bamboo Fibers Coated by Lignin during Super-Heated Steam Treatment and Bio-composites using Same

In order to apply short bamboo fiber (sBF) as a functional reinforcement of bio-composites having specific electrical properties, lignin-surfaced sBF was prepared via super-heated steam (SHS) treatment of bamboo. The sBF was easily isolated from the intrinsic fibrovascular bundle structure of bamboo after SHS treatment and pulverization. The isolated sBF was surfaced by brown-colored hydrophobic compounds, which were lignin-derived compounds generated during the SHS treatment. The functional bio-composites were prepared from the SHS-treated sBF and polypropylene and showed specific antistatic properties. Surface electrical resistance values of the composites decreased significantly with increase in the aspect ratio (AR) value of sBF. It is considered that the lignin-derived surfacing of sBF functions as an electron carrier in the composite, in particular, the longer sBF acts as an effective bridge for transporting electrons over long distances along conductive paths. From a cross-sectional microscopic image of the bio-composite, orientated sBFs were observed in its surface layer, supporting the suggestion of conductive path formation. Further, it was confirmed that the reinforcing effect of the presence of sBF was increased with increasing AR value

Anhydride Production as an Additional Mechanism of Poly(3-hydroxybutyrate) Pyrolysis

Anhydrides production is newly proposed as an additional pyrolysis mechanism of a biopolymer, poly(3‐hydroxybutyrate) (PHB). In spite of many suggestions of multiple degradation mechanisms, simple random chain scission by β‐elimination has been accepted as an exclusive mechanism of the thermal degradation of PHB. However, a wide range of activation energy value of the degradation and the deviation from the random chain scission statistics have suggested the presence of other kinds of mechanism out of the random scission. To confirm other mechanisms out of the random scission, minor pyrolyzates from PHB were characterized with 1H/13C‐NMR, Fourier transform infrared spectroscopy, and fast atom bombardment mass spectrometry. As a result, crotonic anhydride and its oligomers were detected as minor products from condensation reactions between carboxyl groups. The anhydrides production must be one reaction out of the conforming process to the random degradation statistics and contribute to the complexity of PHB pyrolysis. An expected thermal degradation pathway of PHB was proposed

Multiple stage pretreatment affecting the properties of nanocellulose from oil palm frond

Cellulose extraction is an important step prior to nanocellulose production from lignocellulosic materials. The important view of present study rely on pretreatment method for cellulose extraction by comparing their effect on properties of nanocellulose. Oil palm frond was choose in focusing study as the potential value added product. Two pretreatment method were conduct which are multiple stage pretreatment and compared with single stage pretreatment. Peracetic acid was used as totally chlorine free (TCF) bleaching as it is environmental favorable. Multiple stage is the combination of physical, enzymatic and alkaline treatment while single stage represent for soda pulping process using 14% active alkaline charge in high temperature and pressure (160°C, 0.6-1.0 MPa). For multiple stage, superheated steam (300°C, 9 min) used as a prospective in open the fiber structure to allow the subsequent of enzymatic hydrolysis using xylanase. The xylanase was then access to catalyze 1, 4-beta-xylosidase which results in removal of hemicellulose and increase the cellulose content. In addition, xylanase enhanced the delignification process using alkaline treatment of 10% sodium hydroxide. Cellulose nanofibrillation was then conducted using a wet disc mill (WDM). Chemical analysis revealed the cellulose purity from multiple stage and single stage pretreatment with 83.4% and 94.6%. By characterization, the cellulose from multiple stage pretreatment results in high degree of polymerization up to 1,226, higher crystallinity (69.5%) and reach maximum thermal degradation at 326°C. The characteristics of cellulose eventually affected the nanocelluloses properties and by morphology, the nanocellulose produced from both treatment have the diameter size less than 100 nm

Hubungan antara sikap terhadap komputer dengan efikasi swadiri komputer dalam kalangan murid Melayu di Kelantan

Perkembangan Teknologi Maklumat dan Komunikasi (TMK) memerlukan murid sekolah untuk mempersiapkan diri mereka dengan kemahiran menggunakan pelbagai teknologi seperti Internet dan komputer. Dua aspek penting yang perlu dimiliki oleh murid adalah efikasi swadiri komputer dan sikap terhadap komputer. Kertas ini akan membincangkan hubungan antara efikasi swadiri komputer dengan sikap terhadap komputer dalam kalangan 413 orang murid Melayu di negeri Kelantan. Murid yang terlibat dalam kajian ini terdiri daripada mereka yang mengambil mata pelajaran Information and Comunication Technology Literacy (ICTL) di peringkat sekolah menengah. Pemilihan responden telah dijalankan secara rawak. Instrumen yang digunakan dalam kajian ini adalah Computer Self Efficacy oleh Murphy, Coover dan Owen (1989) dan Computer Attitude Scale oleh Jones dan Clark (1994). Secara keseluruhan, purata skor bagi efikasi swadiri komputer adalah baik (Min = 3.93; SP = 0.34) dan murid menunjukkan sikap yang positif terhadap komputer (Min = 3.78; SP = 0.32). Hasil kajian ini juga mendapati terdapat hubungan signifikan antara sikap terhadap komputer dengan efikasi swadiri komputer murid samada secara keseluruhan mahupun jika ditinjau melalui setiap dimensi sikap murid

Production and characterization of cellulases by Bacillus pumilus EB3

Cellulase production from bacteria can be an advantage as the enzyme production rate is normally higher due to bacterial high growth rate. Screening of bacteria, optimisation of fermentation conditions and selection of substrates are important for the successful production of cellulase. This study is conducted to produce cellulase from our local isolate Bacillus pumilus EB3, using carboxymethyl cellulose (CMC) as substrate. Following that, cellulase produced from Bacillus pumilus EB3 was purified using ion exchange chromatography with anion exchanger (HiTrap QXL) for characterisation of the cellulase. Cellulase was successfully produced in 2L stirred tank reactor (STR) with the productivity of 0.53, 3.08 and 1.78 U/L.h and the maximum enzyme activity of 0.011, 0.079 and 0.038 U/mL for FPase, CMCase and β-glucosidase respectively. Purification of cellulase from Bacillus pumilus EB3 using ion exchange chromatography showed that 98.7% of total CMCase was recovered. Protein separation was however based on subtractive separation where the contaminants were bound to the column instead of CMCase. Characterisation of the enzyme found that CMCase from Bacillus pumilus EB3 has a molecular weight range from 30-65 kDa and was optimally active at pH 6.0 and temperature 60℃. The CMCase also retained its activity over a wide pH range (pH 5.0–9.0) and temperature range (30-70℃).Seminar on Engineering and Technology (SET2006), September 4-5, 2006, Putrajaya, Malaysi

Factorial Experimental Design for Biobutanol Production from Oil Palm Frond (OPF) Juice by Clostridium Acetobutylicum ATCC 824

Biobutanol is an alternative energy that can be promising as the future energy source. It can be produced from natural and renewable agriculture wastes such as oil palm frond (OPF) juice by microbes. Clostridium acetobutylicum has the ability to ferment the sugars in OPF juice as carbon source into biobutanol. This research aimed to investigate the effect of independent and interaction factors; initial pH medium (5-7), inoculum size (1-20%), initial total sugars concentration (40-60 g/L), temperature (32-42°C) and yeast extract concentration (1-10 g/L) on the production of biobutanol from oil palm frond (OPF) juice by C. acetobutylicum ATCC 824 using a two level half factorial design which have been developed by the Design Expert Software Version 7.1. Based on the factorial analysis, it was observed that the most significant parameter was yeast extract concentration, which contributes 8.20%, followed by inoculum size and temperature, which were contribute 7.84% and 7.56%, respectively. The analysis showed the R2 value for the model was 0.9805 and the interaction between inoculum size and temperature gave the highest influenced to the fermentation process with contribution up to 16.31%. From the validation experiments, the experimental values were reasonable close to the predicted values with only 5.87% and 10.09% of errors. It confirmed the validity and adequacy of the predicted models. Hence, the data analysis developed from the Design Expert Software could reliably predict biobutanol yields. This study indicated that each of the factors may affect the fermentation process of the biobutanol production

Improved Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Produced by Comamonas sp. EB172 Utilizing Volatile Fatty Acids by Regulating the Nitrogen Source

This study presents the effect of carbon to nitrogen ratio (C/N) (mol/mol) on the cell growth and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) accumulation by Comamonas sp. EB172 in 2 L fermenters using volatile fatty acids (VFA) as the carbon source. This VFA was supplemented with ammonium sulphate and yeast extract in the feeding solution to achieve C/N (mol/mol) 5, 15, 25, and 34.4, respectively. By extrapolating the C/N and the source of nitrogen, the properties of the polymers can be regulated. The number average molecular weight (Mn) of P(3HB-co-3HV) copolymer reached the highest at 838 × 103 Da with polydispersity index (PDI) value of 1.8, when the culture broth was supplemented with yeast extract (C/N 34.4). Tensile strength and Young’s modulus of the copolymer containing 6–8 mol% 3HV were in the ranges of 13–14.4 MPa and 0.26–0.34 GPa, respectively, comparable to those of polyethylene (PE). Thus, Comamonas sp. EB172 has shown promising bacterial isolates producing polyhydroxyalkanoates from renewable carbon materials

Production of bacterial endoglucanase from pretreated oil palm empty fruit bunch by bacillus pumilus EB3

In this study, endoglucanase was produced from oil palm empty fruit bunch (OPEFB) by a locally isolated aerobic bacterium, Bacillus pumilus EB3. The effects of the fermentation parameters such as initial pH, temperature, and nitrogen source on the endoglucanase production were studied using carboxymethyl cellulose (CMC) as the carbon source. Endoglucanase from B. pumilus EB3 was maximally secreted at 37°C, initial pH 7.0 with 10 g/l of CMC as carbon source, and 2 g/l of yeast extract as organic nitrogen source. The activity recorded during the fermentation was 0.076 U/ml. The productivity of the enzyme increased twofold when 2 g/l of yeast extract was used as the organic nitrogen supplement as compared to the non-supplemented medium. An interesting finding from this study is that pretreated OPEFB medium showed comparable results to CMC medium in terms of enzyme production with an activity of 0.063 U/ml. As OPEFB is an abundant solid waste at palm oil mills, it has the potential of acting as a substrate in cellulase production