Oral Presentation 25th Annual Lorne Proteomics Symposium 2020

Rapid separation and identification of beer spoilage bacteria by inertial microfluidics and MALDI-TOF mass spectrometry (#73)

Mark R Condina 1 , Brooke A Dilmetz 1 , Sajad R Bazaz 2 , Jon Meneses 3 , Majid E Warkiani 2 4 , Peter Hoffmann 1
  1. Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
  2. School of Biomedical Engineering, University of Technology Sydney, Sydney, New South Wales, Australia
  3. Coopers Brewery Ltd., Adelaide, South Australia, Australia
  4. Institute of Molecular Medicine, Sechenov University, Moscow 119991, Russia

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS), in combination with Biotyper software, is a rapid, high-throughput, and accurate method for the identification of microbes. Microbial outbreaks in a brewery present a major risk for companies as it can lead to cost-intensive recalls and damage to the brand reputation. MALDI-TOF MS has been implemented into a brewery setting for quality control practices and the identification of beer spoilage microorganisms. However, the applicability of this approach is hindered by compatibility issues associated with mixed cultures, requiring the use of time-consuming selective cultivation techniques prior to identification. We propose a novel, low-cost approach based on the combination of inertial microfluidics and secondary flows in a spiral microchannel for high-throughput and efficient separation of yeasts (Saccharomyces pastorianus and Saccharomyces cerevisiae) from beer spoilage microorganisms (Lactobacillus brevis and Pediococcus damnosus). Flow rates were optimised using S. pastorianus and L. brevis, leading to separation of more than 90% of the L. brevis cells from yeast. The microorganisms were then identified to the species level using the MALDI-TOF MS platform using standard sample preparation protocols. This study shows the high-throughput and rapid separation of spoilage microorganisms (0.3–3 μm) from background yeast (5 μm) from beer, subsequent identification using MALDI Biotyper, and the potential applicability of the approach for biological control in the brewing industry.