Process for producing lower alkyl alcohols from cellulosic biomass using microorganisms

摘要

At least one isolated microorganizm, which converts at least 10% by weight, and preferably 50% by weight, of cellulosic biomass to a lower alkyl alcohol by direct digestion, and which produces at least 4% by volume of the lower alkyl alcohol in an aqueous-based digestion medium.

主权项

1. A composition comprising an ethanol-adapted microorganismal culture in a fermentation broth,
wherein the ethanol-adapted microorganisms in the culture digest a cellulosic biomass in the fermentation broth and convert at least 30% by weight of digested cellulosic biomass to ethanol; wherein the composition comprises by volume thereof at least 5% ethanol; and wherein said ethanol-adapted microorganismal culture is produced by a process comprising: (i) providing a first microorganismal culture wherein the culture microorganism is a member of a taxonomic genus from among Ruminococcus, Enterococcus, Clostridium, Pediococcus, Lactobacillus, and Staphylococcus; (ii) transferring and culturing the first microorganismal culture to the fermentation broth comprising said cellulosic biomass and an initial concentration of ethanol, thereby obtaining a culture broth containing progeny microorganisms; (iii) isolating the progeny microorganisms from the obtained culture broth of (ii), wherein said isolated progeny microorganisms are suspected of having an enhanced ability to grow in the ethanol-containing fermentation broth; and (iv) screening the isolated progeny microorganisms by measuring the ethanol production of a culture of the isolated progeny microorganisms in a fermentation broth comprising said cellulosic biomass and said at least 5% ethanol by volume, wherein screened cultures of ethanol-adapted microorganisms that convert at least 30% by weight of digested cellulosic biomass to ethanol are selected and combined in a fermentation broth, thereby obtaining said composition comprising said ethanol-adapted microorganismal culture in said fermentation broth.