Carbon monoxide fermentation to ethanol by Clostridium autoethanogenum in a bioreactor with no accumulation of acetic acid. (June 2015)

• Record Type: Journal Article
• Authors: Abubackar, Haris Nalakath; Veiga, María C.; Kennes, Christian
• Is Part Of: Bioresource technology. Volume 186(2015)
• Page Start: 122
• Page End: 127
• Publication Date: 2015-06
• Subjects: Bioethanol -- Butanediol -- Selenium -- Syngas -- Tungsten; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2015.02.113
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: The presence of tungsten improved ethanol production from CO fermentation. Selenium and vitamins addition did not improve the ethanol/acetic acid ratio. The 2, 3-butanediol/acetic acid ratio increased with the addition of tungsten. The addition of tungsten, at low pH, resulted in no accumulation of acetic acid. Abstract: Fermentation of CO or syngas offers an attractive route to produce bioethanol. However, during the bioconversion, one of the challenges to overcome is to reduce the production of acetic acid in order to minimize recovery costs. Different experiments were done with Clostridium autoethanogenum . With the addition of 0.75 μM tungsten, ethanol production from carbon monoxide increased by about 128% compared to the control, without such addition, in batch mode. In bioreactors with continuous carbon monoxide supply, the maximum biomass concentration reached at pH 6.0 was 109% higher than the maximum achieved at pH 4.75 but, interestingly, at pH 4.75, no acetic acid was produced and the ethanol titer reached a maximum of 867 mg/L with minor amounts of 2, 3-butanediol (46 mg/L). At the higher pH studied (pH 6.0) in the continuous gas-fed bioreactor, almost equal amounts of ethanol and acetic acid were formed, reaching 907.72 mg/L and 910.69 mg/L respectively.