Optimization of Oil Palm Trunk Core Biodelignification Using Pleurotus Ostreatus
Biodelignification is essential in recovering cellulose from any lignocellulosic material especially for glucose production. Oil palm trunk (OPT) core, a waste from logging activity, has the potential as the source of glucose production due to its high cellulose content. The presence of lignin in OP...
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| Format: | Thesis |
| Language: | English |
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2013
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| Online Access: | http://umpir.ump.edu.my/id/eprint/7282/ http://umpir.ump.edu.my/id/eprint/7282/ http://umpir.ump.edu.my/id/eprint/7282/1/CD7370.pdf |
| Summary: | Biodelignification is essential in recovering cellulose from any lignocellulosic material especially for glucose production. Oil palm trunk (OPT) core, a waste from logging activity, has the potential as the source of glucose production due to its high cellulose content. The presence of lignin in OPT core inhibits any reaction occurred on cellulose. This research focused on the optimization of lignin removal on OPT core using local fungi Pleurotus ostreatus. Chemical analysis on OPT core resulted an 18.47% of lignin content. Enzyme assay showed manganese peroxidase activity 1.6±1.5 U ml-1 at day 6. The screening and optimization experiments were done in 250 mL laboratory glass bottle. During the screening process, seven factors factors were screened at various values; temperature (20°C and 30°C), pH value (5 and 8), humidity (controlled by the presence of silica gel), light exposure, moisture (0.50 mL and 5.00 mL water added per 12 hour), the weight of fungi to medium ratio (1:2 and 1:10) and contact time (2 and 10 days). Design Expert 6.08 software was used for experimental design. Two-level factorial analysis with a fraction of 1/8 was used for the screening process. The lignin content was analyzed via Klason-lignin determination method. The analysis of variance (ANOVA) proved the stability of this model with the coefficient of determination (R2) value at 0.8584. TheNcoefficient regression for linear equation regression showed proved there was a peak point in the model that can be achieved through optimization. Four factors screened were discovered to be the highest contributors to biodelignification; temperature (32.20% contribution), pH value (10.08% contribution), the fungi to medium ratio (8.82% contribution) and moisture content (7.63% contribution). The interactions between temperature and pH value, and the interaction between temperature and the fungi to medium ratio were discovered from the screening process. These four factors were studied in the optimization process with the factors value ranging from temperature (23°C to 27°C), pH value (5.5 to 7.5), moisture content (2.0 mL to 3.5 mL water added per 12 hour) and weight of fungi to medium ratio (2:10 to 4:10). Design Expert 6.08 was used in the optimization process. A central composite design (CCD) with 32 runs and six centre points was applied. From the optimization, the ANOVA showed R2 value was 0.8779 proving that the model was fit for regression. The optimum condition was at; temperature (25.16°C), pH value (7.54), moisture content (2.38 mL water added per 12 hour) and the fungi to medium ratio (1:3.125) with the predicted lignin content of 14.36%. Validation test was conducted to justify this optimum condition with initial lignin content of OPT at 18.47%. The final lignin content was 14.68%. This showed that 20.52% of lignin removal from OPT through biodelignification. It showed an error of 2.23% between the theoretical value and the experimental value. As an additional analysis towards the application of biodelignification, a comparison of sugar produced from treated OPT (biodelignification treatment) and untreated OPT was done via acid hydrolysis process. Glucose concentration was determined using DNS method. The analysis showed that the OPT that went through biodelignification (0.04769 g glucose/ g OPT) had a 25% higher glucose concentration compared to the untreated OPT (0.03792 g glucose/ g OPT). The results from the optimization showed that biodelignification using P. ostreatus was a suitable method for lignin removal of OPT. Along with the acid hydrolysis process; the biodelignification is proved to be applicable as a pretreatment method for glucose production. |
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