High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components Examined
A major economic obstacle in lignocellulosic ethanol production is the low sugar concentrations in the hydrolysate and subsequent fermentation to economically distillable ethanol concentrations. We have previously demonstrated a two-stage fermentation process that recycles xylose with xylose isomera...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-01-01
|
| Series: | Fermentation |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2311-5637/6/1/8 |
| _version_ | 1819107517727244288 |
|---|---|
| author | Sarah W. Harcum Thomas P. Caldwell |
| author_facet | Sarah W. Harcum Thomas P. Caldwell |
| author_sort | Sarah W. Harcum |
| collection | DOAJ |
| description | A major economic obstacle in lignocellulosic ethanol production is the low sugar concentrations in the hydrolysate and subsequent fermentation to economically distillable ethanol concentrations. We have previously demonstrated a two-stage fermentation process that recycles xylose with xylose isomerase to increase ethanol productivity, where the low sugar concentrations in the hydrolysate limit the final ethanol concentrations. In this study, three approaches are combined to increase ethanol concentrations. First, the medium-additive requirements were investigated to reduce ethanol dilution. Second, methods to increase the sugar concentrations in the sugarcane bagasse hydrolysate were undertaken. Third, the two-stage fermentation process was recharacterized with high gravity hydrolysate. It was determined that phosphate and magnesium sulfate are essential to the ethanol fermentation. Additionally, the <i>Escherichia coli</i> extract and xylose isomerase additions were shown to significantly increase ethanol productivity. Finally, the fermentation on hydrolysate had only slightly lower productivity than the reagent-grade sugar fermentation; however, both fermentations had similar final ethanol concentrations. The present work demonstrates the capability to produce ethanol from high gravity sugarcane bagasse hydrolysate using <i>Saccharomyces pastorianus</i> with low yeast inoculum in minimal medium. Moreover, ethanol productivities were on par with pilot-scale commercial starch-based facilities, even when the yeast biomass production stage was included. |
| first_indexed | 2024-12-22T02:55:18Z |
| format | Article |
| id | doaj.art-69678d50b0ff454a8a7e1613ce55dbc2 |
| institution | Directory Open Access Journal |
| issn | 2311-5637 |
| language | English |
| last_indexed | 2024-12-22T02:55:18Z |
| publishDate | 2020-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fermentation |
| spelling | doaj.art-69678d50b0ff454a8a7e1613ce55dbc22022-12-21T18:41:16ZengMDPI AGFermentation2311-56372020-01-0161810.3390/fermentation6010008fermentation6010008High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components ExaminedSarah W. Harcum0Thomas P. Caldwell1Department of Bioengineering, Clemson University, 301 Rhodes Research Center, Clemson, SC 29634-0905, USADepartment of Bioengineering, Clemson University, 301 Rhodes Research Center, Clemson, SC 29634-0905, USAA major economic obstacle in lignocellulosic ethanol production is the low sugar concentrations in the hydrolysate and subsequent fermentation to economically distillable ethanol concentrations. We have previously demonstrated a two-stage fermentation process that recycles xylose with xylose isomerase to increase ethanol productivity, where the low sugar concentrations in the hydrolysate limit the final ethanol concentrations. In this study, three approaches are combined to increase ethanol concentrations. First, the medium-additive requirements were investigated to reduce ethanol dilution. Second, methods to increase the sugar concentrations in the sugarcane bagasse hydrolysate were undertaken. Third, the two-stage fermentation process was recharacterized with high gravity hydrolysate. It was determined that phosphate and magnesium sulfate are essential to the ethanol fermentation. Additionally, the <i>Escherichia coli</i> extract and xylose isomerase additions were shown to significantly increase ethanol productivity. Finally, the fermentation on hydrolysate had only slightly lower productivity than the reagent-grade sugar fermentation; however, both fermentations had similar final ethanol concentrations. The present work demonstrates the capability to produce ethanol from high gravity sugarcane bagasse hydrolysate using <i>Saccharomyces pastorianus</i> with low yeast inoculum in minimal medium. Moreover, ethanol productivities were on par with pilot-scale commercial starch-based facilities, even when the yeast biomass production stage was included.https://www.mdpi.com/2311-5637/6/1/8sugarcane bagasse<i>escherichia coli</i>ethanolxylose isomeraseyeast |
| spellingShingle | Sarah W. Harcum Thomas P. Caldwell High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components Examined Fermentation sugarcane bagasse <i>escherichia coli</i> ethanol xylose isomerase yeast |
| title | High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components Examined |
| title_full | High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components Examined |
| title_fullStr | High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components Examined |
| title_full_unstemmed | High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components Examined |
| title_short | High Gravity Fermentation of Sugarcane Bagasse Hydrolysate by <i>Saccharomyces pastorianus</i> to Produce Economically Distillable Ethanol Concentrations: Necessity of Medium Components Examined |
| title_sort | high gravity fermentation of sugarcane bagasse hydrolysate by i saccharomyces pastorianus i to produce economically distillable ethanol concentrations necessity of medium components examined |
| topic | sugarcane bagasse <i>escherichia coli</i> ethanol xylose isomerase yeast |
| url | https://www.mdpi.com/2311-5637/6/1/8 |
| work_keys_str_mv | AT sarahwharcum highgravityfermentationofsugarcanebagassehydrolysatebyisaccharomycespastorianusitoproduceeconomicallydistillableethanolconcentrationsnecessityofmediumcomponentsexamined AT thomaspcaldwell highgravityfermentationofsugarcanebagassehydrolysatebyisaccharomycespastorianusitoproduceeconomicallydistillableethanolconcentrationsnecessityofmediumcomponentsexamined |