PROTECTING FUEL ETHANOL PRODUCTION FERMENTATION PROCESSES WITH BACTERICIDAL YEAST
Animal Biosciences and Biotechnology Laboratory
2013 Annual Report
1a.Objectives (from AD-416):
Protect the cellulosic ethanolic fermentations from lactobacilli contaminants that reduce the yield and efficiency of biofuel ethanol production.
1b.Approach (from AD-416):
Identify, subclone, and constitutively express lactobacillus peptidoglycan hydrolase antimicrobials on the surface of fermentative yeast.
This work supports the National Program 101 mission statement in the area of developing information, tools, and technologies that can be used to improve animal production systems. Significant progress was made on Component 2: Understanding, Improving, and Effectively Using Animal Genetic and Genomic Resources. Progress on this project focuses on Problem Statement 2E: Improved Techniques for Genetic Modification and Genetic Engineering of Food Animals.
The goal of this work is to identify novel enzyme antimicrobials that will kill bacterial contaminants (Lactobacillus species) that cause huge losses in fermentations required for the production of ethanol for biofuel. There has been significant progress in this project. We have synthesized eight candidate antimicrobial enzymes and have demonstrated their ability to kill the strain Lactobacillus fermentum, the primary fermentation contaminating strain. Yeast were engineered to produce antimicrobial enzymes (lysins), which have been shown to maintain their antimicrobial activity when purified from the yeast. The lysin-producing yeast have been added to mock fermentations and have been shown to reduce or eradicate Lactobacillus fermentum contamination and enhance biofuel production in contaminated fermentations. With evidence that the Lactobacillus lysins are potent antimicrobials, they will next be engineered to kill the bacterium Staphlococcus aureus that causes the mammary gland infection, mastitis. This agreement will initially help improve productivity of ethanol producing fermentations, and increase biofuel production, but eventually will also help to cure mastitis, a major issue for the dairy industry.