Pretreatment Of Oil Palm Frond By Phanerochaete Crysosporium Ck01 And Enzymatic Hydrolysis For Ethanol Production By Saccharomyces Cerevisiae Hc10
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Date
2018-08
Authors
Halim, Farah Amani Abdul
Journal Title
Journal ISSN
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Publisher
Universiti Sains Malaysia
Abstract
Oil palm frond (OPF) is one of the most abundant waste generated from an oil
palm plantation. OPF can be utilized as a feedstock for bioethanol and can
simultaneously address its disposal issue in the plantation. In this project, OPF was
divided into two types of feedstock; biomass and juice by mechanical pressing. Firstly,
the dried biomass was biologically treated using white-rot fungi; Phanerochaete
chrysosporium CK01 for biodelignification. Two parameters were tested; effect of
inoculum size and fermentation duration. The best parameters were inoculum size of
1.0x106 spore/mL and 3 weeks of fermentation duration which gave 27.87% of
delignification. In the second stage, the treated biomass was subjected to enzymatic
hydrolysis by either individual or in combination to produce a sugar hydrolysate. Two
parameters tested were enzyme loading (in individual enzymatic hydrolysis) or
enzyme ratio (in combined enzymatic hydrolysis; Cellulase A “Amano” 3 and
Hemicellulase “Amano” 90) and hydrolysis time. The result shows that the combined
(cellulase and hemicellulase) enzymatic hydrolysis produces higher amount of simple
sugar (5.15g/L) using a combination of enzyme ratio of 1:4 (cellulase:hemicellulase)
with a hydrolysis time of 120 minutes compared to individual enzymatic hydrolysis
(3.26g/L). Prior to beginning of the third stage, the amount of simple sugar in the
hydrolysate (OPFH) and juice (OPFJ) were compared using high performance liquid
chromatography (HPLC) analysis. OPFJ were found to be the better medium and thus be chosen for fermentation in the final stage. In the third stage, OPFJ fermentation was
done using two types of yeast which are Saccharomyces cerevisiae HC10 and
Scheffersomyces stipitis ATCC 5837. The comparison between the two fermentations
show that S. cerevisiae HC10 which managed to produce 12.20% (v/v) ethanol, is a
better fermentation agent compared to S. stipitis ATCC 5837 which produced 9.75%
(v/v) ethanol. The individual sugar utilization by each fermentation shows that the
ability of the yeast to ferment hexoses in the OPFJ is crucial to produce a higher
amount of ethanol efficiently. Later, S. cerevisiae HC10 fermentation on OPFJ was
compared with a fermentation on a modified PDB media to study the growth kinetics.
An overall ethanol yield (fermentation efficiency) obtained was 35.26% in the OPFJ
fermentation and 44.99% in modified PDB media respectively, suggesting that
although OPFJ can solely be fermented without any modification or additional
nutrient, the fermentation was not highly efficient if it were to be commercialised for
production of bioethanol. In conclusion, this project has managed to unveil the good
potential of oil palm frond as fermentation feedstock.
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Keywords
Techonology