摘要:
The present invention provides for novel metabolic pathways leading to acrylate formation in a consolidated bio-processing system (CBP) where lignocellulosic biomass is efficiently converted to acrylate. In one such metabolic pathway, pyruvate is converted to lactate, which is converted to lactoyol-CoA, which is converted to acryloyl-CoA, and which is finally converted to acrylate. In another such metabolic pathway, pyruvate is converted to L-α-alanine, which is converted to L-aspartate, which is converted to β-alanine, which is converted to β-alanyl-CoA, which is converted to acryloyl-CoA, and which is finally converted to acrylate. In yet another metabolic pathway, pyruvate is converted to lactate, and then lactate is converted directly to acrylate. In certain aspects, the invention provides for heterologous expression of one or more enzymes in a mesophilic or thermophilic organism, such as Thermoanaerobacterium saccharolyticum or Clostridium thermocellutn, where the one or more enzymes functions within a novel metabolic pathway as described above to convert pyruvate to acrylate via lactate, or via β alanine and acryloyl-CoA.
摘要:
One aspect of the invention relates to a genetically modified thermophilic or mesophilic microorganism, wherein a first native gene is partially, substantially, or completely deleted, silenced, inactivated, or down-regulated, which first native gene encodes a first native enzyme involved in the metabolic production of an organic acid or a salt thereof, thereby increasing the native ability of said thermophilic or mesophilic microorganism to produce lactate or acetate as a fermentation product. In certain embodiments, the aforementioned microorganism further comprises a first non-native gene, which first non-native gene encodes a first non-native enzyme involved in the metabolic production of lactate or acetate. Another aspect of the invention relates to a process for converting lignocellulosic biomass to lactate or acetate, comprising contacting lignocellulosic biomass with a genetically modified thermophilic or mesophilic microorganism.
摘要:
The present invention provides for novel metabolic pathways leading to propanol, alcohol or polyol formation in a consolidated bioprocessing system (CBP), where lignocellulosic biomass is efficiently converted to such products. More specifically, the invention provides for a recombinant microorganism, where the microorganism expresses one or more native and/or heterologous enzymes; where the one or more enzymes function in one or more engineered metabolic pathways to achieve: (1) conversion of a carbohydrate source to 1,2-propanediol, isopropropanol, ethanol and/or glycerol; (2) conversion of a carbohydrate source to n-propanol and isopropanol; (3) conversion of a carbohydrate source to isopropanol and methanol; or (4) conversion of a carbohydrate source to propanediol and acetone; wherein the one or more native and/or heterologous enzymes is activated, upregulated or downregulated.
摘要:
The present invention relates to the engineering and expression of heterologous cellulosomes in microorganisms in order to facilitate the conversion of biomass to useful products. In some embodiments, the invention relates to the expression of scaffoldin proteins which form the nucleus of a cellulosome. Cellulases or other biomass-degrading enzymes can be non-covalently linked to the scaffoldin protein by virtue of a dockerin domain-cohesin domain interaction.
摘要:
The present invention provides for the isolation and characterization of the cbh1 gene from Schizochytrium aggregatum. In particular, the present invention provides for the nucleic acid and amino acid sequences of Schizochytrium aggregatum cbh1, and domains, variants and derivatives thereof. The present invention further provides for the heterologous expression of Schizochytrium aggregatum Cbh1 in host cells, including yeast, e.g., Saccharomyces cerevisiae. Expression of Schizochytrium aggregatum Cbh1 in host cells will augment cellulose digestion and facilitate ethanol production by those host cells on cellulosic substrates. In certain embodiments, heterologous expression in Saccharomyces cerevisiae is in coordination with heterologous expression of other known, or newly identified saccharolytic enzymes. Therefore, the present invention also provides that the novel Schizochytrium aggregatum Cbh1 gene can utilized in a consolidated bioprocessing system.
摘要:
Crabtree negative organisms such as Kluyveromyces, Pichia, Hansenula and Candida, are used to make selected organic products such as lactic acid. The organisms are cultured in a first culture medium that includes glucose, under conditions that promote cellular respiration. The organisms are then cultured under a second set of conditions that promote production of the selected organic product. The organisms preferably contain an exogenous lactate dehydrogenase gene.
摘要:
The present invention provides for heterologous expression of termite and termite-associated symbiont cellulases. The cellulases can, for example, be codon-optimized and expressed in yeast host cells, such as the yeast Saccharomyces cerevisiae. The cellulases can also be co-expressed in host cells with other cellulases. The expression in such host cells of the termite and termite-associated symbiont cellulases, and variants and combinations thereof, result in yeast with improved cellulosic activity. Thus, such genes and expression systems are useful for efficient and cost-effective consolidated bioprocessing systems.
摘要:
The present invention provides for heterologous expression of termite and termite-associated symbiont cellulases. The cellulases can, for example, be codon-optimized and expressed in yeast host cells, such as the yeast Saccharomyces cerevisiae. The cellulases can also be co-expressed in host cells with other cellulases. The expression in such host cells of the termite and termite-associated symbiont cellulases, and variants and combinations thereof, result in yeast with improved cellulosic activity. Thus, such genes and expression systems are useful for efficient and cost-effective consolidated bioprocessing systems.
摘要:
The invention provides methods and materials related to the production of lactic acid. Specifically, the invention provides methods for producing lactic acid using a crabtree-negative yeast, such as of the Kluyveromyces, Pichia, Candida, Trichosporon and Yamadazmya genera, which have been transformed with a lactate dehydrogenase gene.
摘要:
Host cells, comprising Kluveryomyces expressing heterologous cellulases produce ethanol from cellulose In addition, multiple host cells expressing different heterlogous cellulases can be co-cultured together and used to produce ethanol from cellulose The recombinant yeast strains and co-cultures of the yeast strains can be used to produce ethanol on their own, or can also be used in combination with externally added cellulases to increase the efficiency of sacchanfication and fermentation processes.