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@#Aims:This study was carried out to optimize the fermentation conditions using statistical approach for polyhydroxyalkanoate(PHA) production by a local isolate, Burkholderia cepaciaBPT1213, in the shake flask system.Methodology and results:Throughout this study, B. cepaciaBPT1213 was grown in minimal salt medium (MSM) supplemented with 2% of waste glycerol (86.70% purity).The strain can produce up to 1.33 g/L cell dry weight (CDW) with 22.21% of PHA content, thus giving a total PHA concentration 0.30 g/L before optimization. A factorial design experiment that was carried out showed all parameters KH2PO4, Na2HPO4·2H2O, carbon-to-nitrogen ratio (C/N), initial pH of medium, and temperature significantly affected the growth (cell dry weight, CDW) and PHA content. Response surface methodology (RSM) using central composite design (CCD) was then applied to optimize these parameters. The optimum conditions suggested were at 2.5 g/L KH2PO4, 4.5 g/L Na2HPO4·2H2O, 30 (g/g) C/N ratio, initial medium pH of 8.5 and 37 °C cultivation temperature, with a predicted CDW of 3.43 g/L and PHA content of 45.71% contributing to 1.57 g/L total PHA concentration. The verification experiment resulted in 3.60 g/L of CDW with 48.08% of PHA content contributing to 1.73 g/L total PHA concentration.Conclusion, significance and impact of study:The statistical approach using factorial design and RSM have succeeded in increasing the production of PHA by B. cepaciaBPT1213 using waste glycerol as the sole carbon source which is a promising renewable and cheaper feedsto
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@#Aims:In this study, ten indigenous microalgae samples from freshwater and marine waters from Malaysia, cultured and analysed on proximate and biochemical analysis. The proximate and biochemical analysis consists of starch, carbohydrates, lipid, protein, ash and moisture contents. This study was more focused on screening of starch accumulation in marine and freshwater microalgae cultures. Methodology and results:Based on screening, the results showed that Chlorella salinacontents highest starch of 4.92±0.33%, followed by Spirulinasp. 2.58±1.18%, Isochrysis maritime 0.99±0.33%, and lastly for Nitzschiapanduriformisand Naviculadistanscontents similar percentage of starch (0.44±0.10 and 0.40±0.07%, respectively). Besides starch analysis, proximate analyses(ash, moisture, lipid, protein, and carbohydrates) have been conducted. The results obtained indicated that all the cultures contain more than 4.50% of carbohydrates in average, followed by lipid and protein <1%. The results demonstrate that further optimization and various harvesting stages (early of exponential phase, early of stationary phaseand late stationary phase) may increase lipid, carbohydrates, starch, and protein accumulation. Chlorella salinaand Spirulinasp. will be used to further study on optimization of physical and chemical factors for high starch accumulation. Conclusion, significance and impact of study:In conclusion, this experiment focused more on preliminary screening for further application of starch uses in food and food packaging indust
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Aims: Bioethanol is an environmental friendly energy source with a lot of great prospective and become an alternative to fossil fuels .Oil palm frond juice (OPFJ) is a potential sources of sugars for bioethanol production. The present study aimed to optimize bioethanol production. Methodology and results: Bioethanol fermentation was carried out by Saccharomyces cerevisiae HC10 using OPFJ as substrate in bioreactor with 1.5 L working volume. Growth profile was performed for 42 h with sampling every 3 h interval. Effect of agitation speed (rpm) and volume of OPFJ were screened to select significant factor for high production of bioethanol. Agitation speed at 175 rpm and volume of oil OPFJ; 40% gave 5.25 g/L and 4.52 g/L of ethanol and biomass concentration, respectively. These parameters were further investigated via central composite design (CCD) of Response Surface Methodology (RSM) to maximize bioethanol production. The suggested optimum conditions for bioethanol production were agitation speed at 152 rpm and volume of OPFJ at 39.71% in which giving ethanol concentration of 4.79 g/L. Growth profile after optimization indicated that the highest ethanol concentration (5.75%) was achieved after 15 h of fermentation. Kinetic studies indicated that ethanol yield coefficient (Yp/s) due to consumption of OPFJ and productivity of ethanol was 3.5 fold and 25% increased compared to before optimization, respectively. While, in term of ethanol yield about 9% increased was observed. Conclusion, Significance and Impact of study: This showed that OPFJ can be an alternative new feedstock for bioethanol production using S. cerevisiae HC10.
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Aims: High cost of cellulases remains the most significant barrier to the economical production of bio-ethanol from lignocellulosic biomass (LB). The present study aims at developing a local cellulolytic fungal strain through random mutagenesis coupled with the feasibility of solid-state fermentation (SSF) by utilizing agricultural wastes such as oil palm frond (OPF) as the substrate. Methodology and results: Out of 95 wild isolates tested, native fungal strain Aspergillus niger, designated DWA8 was isolated as the top enzymatic secretor. For quantitative enzyme analysis, SSF was conducted using 1x106 spore/mL inoculated onto 5 g of ground OPF, incubated at room temperature for 7 days, with 70% moisture content and an initial medium pH of 7. Random mutagenesis has always been tempting in the enhancement of enzyme production. In this work, the compounded treatment of microwave, ultraviolet (UVC) and Ethyl Methanesulfonate (EMS) have generated an Aspergillus niger MUE3.06 mutant with an overall increase of 114% in CMCase activity, approximately 70% in FPase and Xylanase activity respectively compared with the parental DWA8 strain. Thus this finding is capable to be fully developed as an established mutational scheme to create highly productive filamentous fungus in a cheap, simple and sustainable way. Conclusion, significance and impact of study: It was the first attempt to explore the combine effect of the three popular mutagens upon cellulases and xylanases. It is believed that more diversified of mutagen types induce more diversified mutation pattern (with instructive planning), which is very desirable in creating new enzymes with novel abilities.
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CellulasesABSTRACT
Aims: It is recognized that laser printed paper are difficult to deink using conventional method. This had lead to the suggestion of enzymatic approach to overcome the problem encountered by commonly employed deinking techniques. The present study aimed to investigate 7 commercially available enzymes for their suitability use in deinking of laser printed paper. Methodology and results: 3 cellulases, hemicellulases, xylanase and 2 lipases were used in enzymatic deinking of laser-printed wastepaper. Cellulase A “Amano”3 (C), Hemicellulase (H) and lipase (L) were selected for used in deinking because they possess either highest activity or broad pH stability compared to others enzymes. Different combination of enzymes was carried out to evaluate their effectiveness in deinking process. CH enzymes sequence was determined to be the most effective sequence in toner removal with 1.90% of brightness increment. However, only 0.95% of brightness increment was gained by enzyme sequence L. Highest deinking efficiency obtained was not proportional to the highest total reducing sugar produced. Conclusion, significance and impact of study: Enzyme (cellulase and hemicellulase) can be used to de-ink laserprinted wastepaper, which are difficult to be deinked by conventional chemical deinking process. Thus, enzyme deinking has high possibility as alternative method to current chemical deinking process which is not environmental friendly.