Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>

Lignocellulose, the main component of a plant cell wall, is a potential renewable bioenergy source. It is composed of cellulose, hemicellulose, and lignin structures. Cellulose is a linear polysaccharide that is hydrolyzed chemically or enzymatically by cellulase. The addition of lignocellulosic bio...

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Main Authors: Amira H. Alabdalall, Asma A. Almutari, Sumayh A. Aldakeel, Ahmed M. Albarrag, Lena A. Aldakheel, Maryam H. Alsoufi, Lulwah Y. Alfuraih, Hesham M. Elkomy
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Language:English
Published: MDPI AG 2023-01-01
Series:Energies
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Online Access:https://www.mdpi.com/1996-1073/16/2/823
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author Amira H. Alabdalall
Asma A. Almutari
Sumayh A. Aldakeel
Ahmed M. Albarrag
Lena A. Aldakheel
Maryam H. Alsoufi
Lulwah Y. Alfuraih
Hesham M. Elkomy
author_facet Amira H. Alabdalall
Asma A. Almutari
Sumayh A. Aldakeel
Ahmed M. Albarrag
Lena A. Aldakheel
Maryam H. Alsoufi
Lulwah Y. Alfuraih
Hesham M. Elkomy
author_sort Amira H. Alabdalall
collection DOAJ
description Lignocellulose, the main component of a plant cell wall, is a potential renewable bioenergy source. It is composed of cellulose, hemicellulose, and lignin structures. Cellulose is a linear polysaccharide that is hydrolyzed chemically or enzymatically by cellulase. The addition of lignocellulosic biomass, such as wheat bran and coffee pulp, into the fermentation culture, induces the production of cellulases. Cellulose accounts for 20% of the enzyme market worldwide, demonstrating benefits in diverse applications, especially bioethanol and biogas generation. The aim is to evaluate the optimal condition for bioethanol production by previously isolated fungal species from different soil types in the eastern region of the Kingdom of Saudi Arabia. This study attempts to evaluate and optimize the culture conditions of lignocellulosic biomass under SSF using the highest cellulases-producer strains in the region: Aspergillus niger and Aspergillus flavus (GenBank Accession No. MT328516 and MT328429, respectively) to produce raw sugar that consequently is used in the next step of bioethanol production. This process has two parts: (1) hydrolyze lignocellulosic biomass to obtain raw sugar using <i>A. niger</i> and <i>A. flavus</i> that produce cellulase, and (2) produce bioethanol through the conversion of the raw sugar produced from the cellulolysis into ethanol using Saccharomyces cerevisiae. The optimal conditions under SSF were seven days of incubation, 5% glucose as a carbon source, 1% ammonium sulfate as a nitrogen source, and 80% moisture for both isolates. Biochemical characterization showed stability for the immobilized enzyme in all temperature ranges (from 20 °C to 70 °C), while the free enzyme exhibited its maximum at 20 °C of 1.14 IU/mL. CMCase production was the highest at pH 4.0 (1.26 IU/mL) for free enzyme and at pH 5.0 (2.09 IU/mL) for the immobilized form. The CMCase activity increased steadily with an increase in water level and attained a maximum of 80% moisture content. The maximum enzyme activity was with coffee pulp as a substrate of 7.37 IU/mL and 6.38 IU/mL for <i>A. niger</i> and <i>A. flavus</i> after seven days of incubation, respectively. The Carboxymethyl Cellulase (CMCase) activity in immobilized enzymes showed good storage stability under SSF for six weeks, maintaining 90% of its initial activity, while the free enzyme retained only 59% of its original activity. As a carbon source, glucose was the best inducer of CMCase activity with coffee pulp substrate (7.41 IU/mL and 6.33 IU/mL for <i>A. niger</i> and <i>A. flavus</i>, respectively). In both fungal strains, ammonium sulfate caused maximum CMCase activities with coffee pulp as substrate (7.62 IU/mL and 6.47 IU/mL for <i>A. niger</i> and <i>A. flavus</i>, respectively). Immobilized <i>S. cerevisiae</i> showed an increase in ethanol production compared to free cells. In the case of immobilized <i>S. cerevisiae</i> cells, the concentration of ethanol was increased steadily with increasing fermentation time and attained a maximum of 71.39 mg/mL (<i>A. niger</i>) and 11.73 mg/mL (<i>A. flavus</i>) after 72 h of fermentation.
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spelling doaj.art-3a748ca277a740edb4cee7170a2f54da2023-11-30T22:04:35ZengMDPI AGEnergies1996-10732023-01-0116282310.3390/en16020823Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>Amira H. Alabdalall0Asma A. Almutari1Sumayh A. Aldakeel2Ahmed M. Albarrag3Lena A. Aldakheel4Maryam H. Alsoufi5Lulwah Y. Alfuraih6Hesham M. Elkomy7Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi ArabiaDepartment of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi ArabiaThe National Center for Genomic Technology (NCGT), Life Science and Environment Research Institute, King Abdulaziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11461, Saudi ArabiaDepartment of Pathology, School of Medicine, King Saud University, P.O. Box 800, Riyadh 11461, Saudi ArabiaNEOM Community 1, Building 4758, P.O. Box 10, Gayal 49643, Saudi ArabiaDepartment of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi ArabiaDepartment of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi ArabiaDepartment of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi ArabiaLignocellulose, the main component of a plant cell wall, is a potential renewable bioenergy source. It is composed of cellulose, hemicellulose, and lignin structures. Cellulose is a linear polysaccharide that is hydrolyzed chemically or enzymatically by cellulase. The addition of lignocellulosic biomass, such as wheat bran and coffee pulp, into the fermentation culture, induces the production of cellulases. Cellulose accounts for 20% of the enzyme market worldwide, demonstrating benefits in diverse applications, especially bioethanol and biogas generation. The aim is to evaluate the optimal condition for bioethanol production by previously isolated fungal species from different soil types in the eastern region of the Kingdom of Saudi Arabia. This study attempts to evaluate and optimize the culture conditions of lignocellulosic biomass under SSF using the highest cellulases-producer strains in the region: Aspergillus niger and Aspergillus flavus (GenBank Accession No. MT328516 and MT328429, respectively) to produce raw sugar that consequently is used in the next step of bioethanol production. This process has two parts: (1) hydrolyze lignocellulosic biomass to obtain raw sugar using <i>A. niger</i> and <i>A. flavus</i> that produce cellulase, and (2) produce bioethanol through the conversion of the raw sugar produced from the cellulolysis into ethanol using Saccharomyces cerevisiae. The optimal conditions under SSF were seven days of incubation, 5% glucose as a carbon source, 1% ammonium sulfate as a nitrogen source, and 80% moisture for both isolates. Biochemical characterization showed stability for the immobilized enzyme in all temperature ranges (from 20 °C to 70 °C), while the free enzyme exhibited its maximum at 20 °C of 1.14 IU/mL. CMCase production was the highest at pH 4.0 (1.26 IU/mL) for free enzyme and at pH 5.0 (2.09 IU/mL) for the immobilized form. The CMCase activity increased steadily with an increase in water level and attained a maximum of 80% moisture content. The maximum enzyme activity was with coffee pulp as a substrate of 7.37 IU/mL and 6.38 IU/mL for <i>A. niger</i> and <i>A. flavus</i> after seven days of incubation, respectively. The Carboxymethyl Cellulase (CMCase) activity in immobilized enzymes showed good storage stability under SSF for six weeks, maintaining 90% of its initial activity, while the free enzyme retained only 59% of its original activity. As a carbon source, glucose was the best inducer of CMCase activity with coffee pulp substrate (7.41 IU/mL and 6.33 IU/mL for <i>A. niger</i> and <i>A. flavus</i>, respectively). In both fungal strains, ammonium sulfate caused maximum CMCase activities with coffee pulp as substrate (7.62 IU/mL and 6.47 IU/mL for <i>A. niger</i> and <i>A. flavus</i>, respectively). Immobilized <i>S. cerevisiae</i> showed an increase in ethanol production compared to free cells. In the case of immobilized <i>S. cerevisiae</i> cells, the concentration of ethanol was increased steadily with increasing fermentation time and attained a maximum of 71.39 mg/mL (<i>A. niger</i>) and 11.73 mg/mL (<i>A. flavus</i>) after 72 h of fermentation.https://www.mdpi.com/1996-1073/16/2/823<i>Aspergillus niger</i><i>Aspergillus flavus</i>cellulasesubmerged fermentationsolid state fermentation<i>Saccharomyces cerevisiae</i>
spellingShingle Amira H. Alabdalall
Asma A. Almutari
Sumayh A. Aldakeel
Ahmed M. Albarrag
Lena A. Aldakheel
Maryam H. Alsoufi
Lulwah Y. Alfuraih
Hesham M. Elkomy
Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>
Energies
<i>Aspergillus niger</i>
<i>Aspergillus flavus</i>
cellulase
submerged fermentation
solid state fermentation
<i>Saccharomyces cerevisiae</i>
title Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>
title_full Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>
title_fullStr Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>
title_full_unstemmed Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>
title_short Bioethanol Production from Lignocellulosic Biomass Using <i>Aspergillus niger</i> and <i>Aspergillus flavus</i> Hydrolysis Enzymes through Immobilized <i>S. cerevisiae</i>
title_sort bioethanol production from lignocellulosic biomass using i aspergillus niger i and i aspergillus flavus i hydrolysis enzymes through immobilized i s cerevisiae i
topic <i>Aspergillus niger</i>
<i>Aspergillus flavus</i>
cellulase
submerged fermentation
solid state fermentation
<i>Saccharomyces cerevisiae</i>
url https://www.mdpi.com/1996-1073/16/2/823
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