Saccharomyces cerevisiae surface displayed recombinant LysKB317 endolysin mitigates Limosilactobacillus fermentum infection of corn mash fermentations

Authors: Lu, Shao; Liu, Siqing; PATEL, MAULIK - Orise Fellow; Skory, Christopher

Submitted to: Society of Industrial Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/10/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Commercial ethanol fermentation facilities have traditionally relied on antibiotics for bacterial contamination control. Here we demonstrate alternative approaches to treat contamination using novel recombinantly expressed and purified endolysin, LysKB317, to target common bacterial contaminants, such as Limosilactobacillus fermentum, isolated from commercial fuel ethanol fermentation plants. We also demonstrated utilizing Saccharomyces cerevisiae surface displayed LysKB317 confirmed by immunostaining and confocal microscopy to actively control contaminant bacteria. Results showed purified recombinant LysKB317 (33 kDa) was active against 28 bacterial strains and was stable from pH 4.5 – 7.5 for 48 h. LysKB317 is temperature tolerant up to 50°C and was stable in 30% ethanol for up to 72 h. In a small-scale corn mash fermentation, 1 µM endolysin reduced bacterial load in infected cultures by 3-log fold change and restored concentration of fermentation products (ethanol, residual glucose, lactic acid, and acetic acids) at similar levels to uncontaminated controls. In yeast displayed LysKB317, at least 1-log reduction was observed and suggests LysKB317 endolysin may be developed as an alternative to antibiotics for contamination control during fuel ethanol fermentation.