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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
Subjects:
QD Chemistry
Online Access:https://eprints.ums.edu.my/id/eprint/26570/1/Biochemical%20characterization%20and%20optimization%20of%20cellulases%20for%20empty%20fruit%20bunch%20Saccharification.pdf
https://eprints.ums.edu.my/id/eprint/26570/
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spelling my.ums.eprints.265702021-01-06T00:31:35Z https://eprints.ums.edu.my/id/eprint/26570/ Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification 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 NonPeerReviewed text en https://eprints.ums.edu.my/id/eprint/26570/1/Biochemical%20characterization%20and%20optimization%20of%20cellulases%20for%20empty%20fruit%20bunch%20Saccharification.pdf Obeng Eugene Marfo (2017) Biochemical characterization and optimization of cellulases for empty fruit bunch Saccharification. Masters thesis, Universiti Malaysia Sabah.
institution Universiti Malaysia Sabah
building UMS Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Sabah
content_source UMS Institutional Repository
url_provider http://eprints.ums.edu.my/
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
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
publishDate 2017
url https://eprints.ums.edu.my/id/eprint/26570/1/Biochemical%20characterization%20and%20optimization%20of%20cellulases%20for%20empty%20fruit%20bunch%20Saccharification.pdf
https://eprints.ums.edu.my/id/eprint/26570/
_version_ 1760230516029652992
score 13.211869

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