Lactic acid production from lime-treated wheat straw by Bacillus coagulans: neutralization of acid by fed-batch addition of alkaline substrate
| Autor: | Diana Visser, Robert R. Bakker, Gerrit Eggink, Ruud A. Weusthuis, Ed de Jong, Ronald H. W. Maas, Mickel Leonardus August Jansen |
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| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Bio Process Engineering
Biobased Chemistry and Technology growth Calcium hydroxide Bacillus engineering.material Applied Microbiology and Biotechnology complex mixtures Industrial Microbiology Hydrolysis chemistry.chemical_compound Bioreactors Enzymatic hydrolysis Food science fermentation Triticum Lime VLAG Waste Products biology biomass Chemistry pH control food and beverages Oxides Lactic acid General Medicine Calcium Compounds Hydrogen-Ion Concentration Straw pretreatment biology.organism_classification Biotechnological Products and Process Engineering Biodegradation Environmental Biochemistry AFSG Biobased Products engineering Bacillus coagulans Fermentation Lime-treated wheat straw Simultaneous saccharification and fermentation Biotechnology |
| Zdroj: | Applied Microbiology and Biotechnology, 78(5), 751-758 Applied Microbiology and Biotechnology 78 (2008) 5 Applied Microbiology and Biotechnology |
| ISSN: | 0175-7598 |
| Popis: | Conventional processes for lignocellulose-to-organic acid conversion requires pretreatment, enzymatic hydrolysis, and microbial fermentation. In this study, lime-treated wheat straw was hydrolyzed and fermented simultaneously to lactic acid by an enzyme preparation and Bacillus coagulans DSM 2314. Decrease in pH because of lactic acid formation was partially adjusted by automatic addition of the alkaline substrate. After 55 h of incubation, the polymeric glucan, xylan, and arabinan present in the lime-treated straw were hydrolyzed for 55%, 75%, and 80%, respectively. Lactic acid (40.7 g/l) indicated a fermentation efficiency of 81% and a chiral l(+)-lactic acid purity of 97.2%. In total, 711 g lactic acid was produced out of 2,706 g lime-treated straw, representing 43% of the overall theoretical maximum yield. Approximately half of the lactic acid produced was neutralized by fed-batch feeding of lime-treated straw, whereas the remaining half was neutralized during the batch phase with a Ca(OH)2 suspension. Of the lime added during the pretreatment of straw, 61% was used for the neutralization of lactic acid. This is the first demonstration of a process having a combined alkaline pretreatment of lignocellulosic biomass and pH control in fermentation resulting in a significant saving of lime consumption and avoiding the necessity to recycle lime. |
| Databáze: | OpenAIRE |
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