Novel bacteria and methods of use thereof

Abstract

This invention relates generally to the field of microbial fermentation of gases. It more particularly relates to a novel strain of Clostridium autoethanogenum bacteria with improved efficiency in the production of ethanol by anaerobic fermentation of substrates containing carbon monoxide (CO).

1 - 29 . (canceled) 
     
     
         30 . A biologically pure isolate of a bacterium derived from  Clostridium autoethanogenum  wherein the selected bacterium ferments a substrate comprising CO to products comprising ethanol and wherein the bacterium has one or more improvements compared to a parent strain, the one or more improvements being selected from the group consisting of;
 a. an increased production rate;   b. an increased growth rate;   c. an increased carbon monoxide uptake;   d. an increased tolerance to alcohol; and   e. a higher alcohol to acid production ratio.   
     
     
         31 . The bacterium of claim  1  wherein the parent strain is  Clostridium autoethanogenum  strain deposited at the German Collection of Microorganisms and cell cultures (DSMZ) under the accession number DSM19630. 
     
     
         32 . The selected bacterium of claim  1  wherein the bacterium is  Clostridium autoethanogenum  strain deposited at DSMZ under the accession number DSM23693. 
     
     
         33 . A biologically pure isolate of  Clostridium autoethanogenum  having at least one DNA sequence selected from Seq. ID. 1 to Seq. ID. 17. 
     
     
         34 . The bacterium of  claim 30  wherein the production rate of the bacterium is at least 2 g ethanol/L fermentation broth/gram of biomass/day. 
     
     
         35 . The bacterium of  claim 31  wherein the production rate of the bacterium is at least 2 g ethanol/L fermentation broth/gram of biomass/day. 
     
     
         36 . The bacterium of  claim 32  wherein the production rate of the bacterium is at least 2 g ethanol/L fermentation broth/gram of biomass/day. 
     
     
         37 . The bacterium of  claim 33  wherein the bacterium ferments a substrate comprising CO to products comprising ethanol and wherein the production rate of the bacterium is at least 2 g ethanol/L fermentation broth/gram of biomass/day 
     
     
         38 . The bacterium of  claim 34  wherein the specific productivity is at least 7 g ethanol/L fermentation broth/gram of biomass/day. 
     
     
         39 . The bacterium of  claim 30  wherein the products comprise ethanol and acetate. 
     
     
         40 . The bacterium of  claims 30  wherein production rate of the bacterium is at least 10 g of ethanol/L of fermentation broth/day. 
     
     
         41 . The bacterium of  claim 40  wherein the production rate of the bacterium is at least 50 g of ethanol/L of fermentation broth/day. 
     
     
         42 . The bacterium of  claims 39  wherein the ethanol to acetate ratio is at least 2:1 
     
     
         43 . The bacterium of any one of  claim 30  wherein the bacterium has a specific uptake of CO of at least 1.0 mmol CO/min/g biomass. 
     
     
         44 . The selected bacterium of  claim 43  wherein the bacterium has a specific uptake of CO of at least 2.0 mmol CO/min/g biomass. 
     
     
         45 . The bacterium of  claim 30  wherein the bacterium has a specific growth rate of at least 0.8 day −1 . 
     
     
         46 . The bacterium of  claim 30  wherein the bacterium tolerates an alcohol concentration of up to 30 g/L of fermentation broth. 
     
     
         47 . The bacterium of  claim 46  wherein the bacterium tolerates an alcohol concentration of up to 70 g/L of fermentation broth.