Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification

Empty (palm) fruit bunch (EFB) is one of the abundant agro-wastes generated by the oil palm sector in Malaysia. The EFB waste is normally returned to the plantation to replenish the soil or burnt in incinerators for energy generation. Besides the environmental consequences of these practices, substa...

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Main Author: Obeng Eugene Marfo
Format: Thesis
Language:English
Published: 2017
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Online Access:https://eprints.ums.edu.my/id/eprint/26570/1/Biochemical%20characterization%20and%20optimization%20of%20cellulases%20for%20empty%20fruit%20bunch%20Saccharification.pdf
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spelling my-ums-ep.265702021-01-06T00:31:35Z Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification 2017 Obeng Eugene Marfo QD Chemistry Empty (palm) fruit bunch (EFB) is one of the abundant agro-wastes generated by the oil palm sector in Malaysia. The EFB waste is normally returned to the plantation to replenish the soil or burnt in incinerators for energy generation. Besides the environmental consequences of these practices, substantial amount of the EFB remains unutilized. However, EFB is a lignocellulosic biomass with high potential for the production of biochemicals such as bioethanol. The possible conversion of this feedstock into high value-added products would present high economic benefit to the oil palm industry and the country at large. In this research, a cell surface display technology, called the autodisplay system, was used to express recombinant cellulases for the saccharification of EFB. An investigation of a suitable expression platform between Escherichia coli and Pseudomonas putida revealed the latter as the better host (expression) system for the recombinant cellulase. The biochemical characterization of the cellulases (i.e., endoglucanase, BsCel5A; exoglucanase, CelK: β-glucosidase, BglA) revealed that the enzymes are active over a broad range of pH (4-10) and temperature (30-100 oC). The pH and temperature optima were BsCel5A (pH 6; 60 oC), CelK (pH 6; 60-70 oC), and BglA (pH 6; 50 oC). Also, in an attempt to improve the functionality of the enzymes, different additives (e.g., salts and surfactants) were studied for their influence on the cellulases. The results showed that CaCl2 and Tween 20 improve the synergistic performance of the enzymes on cellulose. Lastly, since cellulose depolymerization requires the three cellulases in different proportions, a simplex-lattice mixture design was employed to identify the optimum blend composition of the whole cell biocatalyst. The results revealed a blend ratio of 1: 1.6: 1.4 of endoglucanase: exoglucanase: β-glucosidase as the “sweet spot” for optimum sugar yield. The application of this blend generated about 0.354 and 0.446 g/l of reduced sugars from filter paper and 2.5% pretreated EFB, respectively. The supplementation of the enzyme blend with CaCl2 and Tween 20 resulted in a significant increase in sugar yield. The overall outcome of this research is a step in the right direction for wealth from the abundant EFB waste. 2017 Thesis https://eprints.ums.edu.my/id/eprint/26570/ https://eprints.ums.edu.my/id/eprint/26570/1/Biochemical%20characterization%20and%20optimization%20of%20cellulases%20for%20empty%20fruit%20bunch%20Saccharification.pdf text en validuser mphil masters Universiti Malaysia Sabah Biotechnology Research Institute
institution Universiti Malaysia Sabah
collection UMS Institutional Repository
language English
topic QD Chemistry
spellingShingle QD Chemistry
Obeng Eugene Marfo
Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification
description Empty (palm) fruit bunch (EFB) is one of the abundant agro-wastes generated by the oil palm sector in Malaysia. The EFB waste is normally returned to the plantation to replenish the soil or burnt in incinerators for energy generation. Besides the environmental consequences of these practices, substantial amount of the EFB remains unutilized. However, EFB is a lignocellulosic biomass with high potential for the production of biochemicals such as bioethanol. The possible conversion of this feedstock into high value-added products would present high economic benefit to the oil palm industry and the country at large. In this research, a cell surface display technology, called the autodisplay system, was used to express recombinant cellulases for the saccharification of EFB. An investigation of a suitable expression platform between Escherichia coli and Pseudomonas putida revealed the latter as the better host (expression) system for the recombinant cellulase. The biochemical characterization of the cellulases (i.e., endoglucanase, BsCel5A; exoglucanase, CelK: β-glucosidase, BglA) revealed that the enzymes are active over a broad range of pH (4-10) and temperature (30-100 oC). The pH and temperature optima were BsCel5A (pH 6; 60 oC), CelK (pH 6; 60-70 oC), and BglA (pH 6; 50 oC). Also, in an attempt to improve the functionality of the enzymes, different additives (e.g., salts and surfactants) were studied for their influence on the cellulases. The results showed that CaCl2 and Tween 20 improve the synergistic performance of the enzymes on cellulose. Lastly, since cellulose depolymerization requires the three cellulases in different proportions, a simplex-lattice mixture design was employed to identify the optimum blend composition of the whole cell biocatalyst. The results revealed a blend ratio of 1: 1.6: 1.4 of endoglucanase: exoglucanase: β-glucosidase as the “sweet spot” for optimum sugar yield. The application of this blend generated about 0.354 and 0.446 g/l of reduced sugars from filter paper and 2.5% pretreated EFB, respectively. The supplementation of the enzyme blend with CaCl2 and Tween 20 resulted in a significant increase in sugar yield. The overall outcome of this research is a step in the right direction for wealth from the abundant EFB waste.
format Thesis
qualification_name Master of Philosophy (M.Phil.)
qualification_level Master's degree
author Obeng Eugene Marfo
author_facet Obeng Eugene Marfo
author_sort Obeng Eugene Marfo
title Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification
title_short Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification
title_full Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification
title_fullStr Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification
title_full_unstemmed Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification
title_sort biochemical characterization and optimization of cellulases for empty fruit bunch saccharification
granting_institution Universiti Malaysia Sabah
granting_department Biotechnology Research Institute
publishDate 2017
url https://eprints.ums.edu.my/id/eprint/26570/1/Biochemical%20characterization%20and%20optimization%20of%20cellulases%20for%20empty%20fruit%20bunch%20Saccharification.pdf
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