Affiliation:
1. Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Strasse 2, 17489 Greifswald, Germany
2. Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, 17489 Greifswald, Germany
Abstract
Foods consumed raw, such as lettuce, can host food-borne human-pathogenic bacteria. In the worst-case, these diseases cause to death. To limit illness and industrial losses, one innovative sanitation method is non-thermal plasma, which offers an extremely efficient reduction of living microbial biomass. Unfortunately, the total viable count (TVC), one of the most common methods for quantifying antimicrobial effects, provides no detailed insights into the composition of the surviving microbial community after treatment. To address this information gap, different special agars were used to investigate the reduction efficiency of plasma-treated water (PTW) on different native cultivable microorganisms. All tested cultivable microbial groups were reduced using PTW. Gram-negative bacteria showed a reduction of 3.81 log10, and Gram-positive bacteria showed a reduction of 3.49 log10. Fungi were reduced by 3.89 log10. These results were further validated using a live/dead assay. MALDI-ToF (matrix-assisted laser-desorption-ionization time-of-flight)-based determination was used for a diversified overview. The results demonstrated that Gram-negative bacteria were strongly reduced. Interestingly, Gram-positive bacteria and fungi were reduced by nearly equal amounts, but could still recover from PTW treatment. MALDI-ToF mainly identified Pseudomonas spp. and groups of Bacillus on the tested lettuce. These results indicate that the PTW treatment could efficiently achieve a ubiquitous, spectrum-wide reduction of microbial life.
Funder
Federal Republic of Germany, Federal Ministry of Food and Agriculture
Federal Ministry of Education and Research
Reference74 articles.
1. Edlund, A., Yang, Y., Yooseph, S., He, X., Shi, W., and McLean, J.S. (2018). Uncovering complex microbiome activities via metatranscriptomics during 24 hours of oral biofilm assembly and maturation. Microbiome, 6.
2. The human microbiome project;Turnbaugh;Nature,2007
3. Defining the human microbiome;Ursell;Nutr. Rev.,2012
4. What is the microbiome?;Amon;Arch. Dis. Child.-Educ. Pract.,2017
5. Van Der Heijden, M.G., and Hartmann, M. (2016). Networking in the plant microbiome. PLoS Biol., 14.