Production Of 2 Propanol Butanol And Ethanol Using Clostridium Beijerinckii Optonii

Author : Guk Hee S. Youn
Publisher :
ISBN 13 :
Total Pages : 126 pages
Book Rating : 4.:/5 (1 download)

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Download or read book Bioethanol and Biobutanol Production with Clostridium Carboxidivorans, Clostridium Beijerinckii, and Co-culture from Biomass written by Guk Hee S. Youn and published by . This book was released on 2017 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clostridium carboxidivorans (NCIMB 15243) is a well-known acetogenic bacterium with the capability to produce acetyl-CoA and subsequently biofuel products such as ethanol and butanol from waste gas such as CO2 and H2. To be more specific, C. carboxidivorans can utilize CO2 and H2 via the reductive acetyl-CoA or Wood-Ljungdahl pathway to produce organic acids, such as acetate and butyrate, and alcohols, such as ethanol and butanol. Clostridium beijerinckii (NCIMB 8052) produces CO2 and H2 as waste products from converting pyruvate into acetyl-CoA. Because these two different Clostridium strains use two different, but very similar, metabolic pathways that rely on two different substrates to produce ethanol and butanol, both individual strain and co-cultured fermentative profiles were studied in autotrophic fermentation with CO2/H2 and heterotrophic fermentation with glucose as carbon and energy source. During both fermentations, initial medium pH values of 6.1 and 7.1 were studied for optimal ethanol and butanol production without any pH adjustments during glucose and CO2/H2 gas fermentations. Both fermentations were performed in serum bottles containing 50 ml of CGM medium. All serum bottles were incubated in a shaking incubator with agitation at 150 rpm at 25C or 37C. We observed that more acids and alcohols were produced with the higher initial pH of 7.1 in glucose and CO2/H2 gas fermentations. To explore the effect of temperature shift on alcohol production, serum bottles were incubated in 37C shaker for the first 24 hours then in 25C shaker for the rest of fermentation. During the glucose fermentation, two co-culture batches were able to produce significant amount of butanol by utilizing temperature shift technique. Since we have observed that C. carboxidivorans can more effectively convert CO2 into ethanol rather than butanol, we also examined the effect of co-culturing it with C. beijerinckii in gas fermentation. Co-culture batches were able to boost butanol productivity in CO2/H2 gas fermentation by converting acetyl-CoA produced by C. carboxidivorans prior to the second inoculation of C. beijerinckii at 37C.