Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/3/2015
Publication Date: 2/3/2015
Citation: Hughes, S.R., Bischoff, K.M., Liu, S., Rich, J.O. 2015. Development of synthetic chromosomes and improved microbial strains to utilize cellulosic feedstocks and express valuable coproducts for sustainable production of biofuels from corn [abstract]. Corn Processing Workshop and International Starch Technology Conference.
Technical Abstract: A sustainable biorefinery must convert a broad range of renewable feedstocks into a variety of product streams, including fuels, power, and value-added bioproducts. To accomplish this, microbial-based technologies that enable new commercially viable coproducts from corn-to-ethanol biofuel fermentations are necessary. Peptides and proteins have great potential as coproducts from a biorefining process. Developing a robust protein/peptide expression system as a technology platform will provide opportunities to create novel microbial catalysts via genetic engineering and mutagenesis that enable sustainable processes for producing biofuel from corn biomass and liquid waste streams while concomitantly producing several value-added products. A synthetic chromosome system for stable expression of enzymes for pentose utilization and of a peptide coproduct was developed and transformed into Saccharomyces cerevisiae. This yeast strain is being evaluated for yield of coproduct and production of ethanol from corn. Other microbial yeast strains to bioprocess all sugars and proteins of a plant biomass and produce a mixture of yeast cells, oil, biofuels, and other high-value products are also being developed and evaluated. An artificial chromosome expression platform utilizing mutant Yarrowia lipolytica host strains that produce high levels of ammonia and oil is being evaluated for improved renewable gas and biodiesel and for increasing the range of feedstocks used for commodity chemicals production, including ammonia, concomitantly with expression of genes for value-added protein coproducts. A robotic workcell process is being used for the rapid assembly of chromosomes and transformation of Yarrowia lipolytica in a single operation without need for traditional cloning strategies. Chromosomes are assembled de novo using polymerase chain reaction (PCR) and oligonucleotide assembly paradigms coupled with strategies for optimizing various regions of this synthetic chromosome. Automated assembly of the chromosome units allows production of the telomeric regions with selectable markers followed by screening for promoter and terminator regions for polyprotein expression cassettes and offers the possibility of adding other optimized expression cassettes. This presentation will focus on the development of new microbial catalysts with synthetic chromosomes to ferment waste biomass streams, such as stover, cobs, and other agricultural waste materials, for production of food, feed, fertilizer, biofuel, value-added proteins and peptides, renewable gas, and biobased chemicals.