Biofuels Production programs
Yeast Produced Endolysins to Prevent Bacterial Infections of Ethanol Fermentations
Generally, fuel ethanol fermentations are not designed to be carried out under pure culture conditions and are prone to bacterial infections, typically by lactobacilli. Bacterial infections decrease the profitability of ethanol production by decreasing ethanol yield. In extreme cases, bacterial infections can lead to a "stuck" fermentation (little or no conversion of sugar into ethanol) which results in plant closures for cleaning. To combat bacterial infections, ethanol producers could use antibiotics. Unfortunately, the use of antibiotics has three significant negatives: I) cost of antibiotics; 2) limited long-term usefulness due to antibiotic resistance; and 3) strengthening lack of support for use of antibiotics in agriculture. In fact, concern over the development of antibiotic resistance in ethanol fermentations has led to a ban of antibiotic use in Europe and pressure is mounting for a similar ban in the United States. Our goal is to develop an inexpensive and effective alternative to antibiotics in fuel ethanol fermentations.
Generally, fuel ethanol fermentations are not designed to be carried out under pure culture conditions and are therefore prone to bacterial infections, typically by lactic acid bacteria. Our goal, beginning in 2014, is to develop a novel solution for these infections using endolysins, phage-encoded lytic enzymes. To date, we have successfully expressed a model endolysin with Escherichia coli and Pichia pastoris. We have confirmed that endolysins can effectively treat a lactic acid bacteria infection of a model yeast fermentation. Further studies include the identification, characterization and optimization of novel endolysins.
Our goal is to develop a novel solution for these infections using endolysins, phage-encoded lytic enzymes. To date, we have successfully expressed a model endolysin with Escherichia coli and Pichia pastoris. Our recombinant endolysin has activity against many contaminants isolated from ethanol fermentations. Future experiments will identify novel endolysins with broader activity.