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VBNC in yeast
A couple of published studies have reported inducing the VBNC state in bacteria strains that were isolated from contaminated beer. Liu et al. (2017) were able to induce a VBNC state (meaning that they were not able to grow on growth media for up to 14 days) in a strain of ''Lactobacillus lindneri'', a species that is responsible for 15-25% of spoiled beer reports, and determined VBNC via a Live/Dead BacLight® bacterial viability kit. They induced this state by storing the cells in beer at 0°C without shaking for 190 days. They also found that storing the VBNC cells at -80°C in glycerol stocks was the best way to maintain the cells. They were able to resuscitate the cells by growing them on MRS media that had 500-1000-μL of the enzyme catalase spread onto them (trying higher temperatures did not work to resuscitate, nor using higher concentrations of MRS), thus showing that brewers can use catalase to help grow VBNC state ''L. lindneri'' cells on MRS media (and perhaps other species of ''Lactobacillus'' as well). It took 3-4 days to begin showing signs of growth on the catalase supplemented MRS media. It was also demonstrated that VBNC cells could grow in beer after 30 days of incubation, and showed final cell counts similar to normal ''L. lindneri'' and resuscitated cells <ref>[https://www.sciencedirect.com/science/article/pii/S0882401017303030?via%3Dihub First study on the formation and resuscitation of viable but nonculturable state and beer spoilage capability of Lactobacillus lindneri. Junyan Liu, Lin Lia, Bing Li, Brian M. Peters, Yang Deng, Zhenbo Xua, Mark E. Shirtliff. Microbial Pathogenesis, Vol 107. 2017. DOI: https://doi.org/10.1016/j.micpath.2017.03.043.]</ref>. Lui et al. (2018) reproduced these results with a hop tolerant strain of ''L. brevis'' <ref name="Liu_2018" />.
=====VBNC In Yeast=====
While the VBNC state has mostly been studied in detail for bacteria, it has also been suggested that this state is also possible with eukaryotes (yeast). It has been reported that although there are many methods for detecting ''Brettanomyces'' in winemaking, there are cases when ''Brettanomyces'' is not found using culturing techniques, but years later have still infected wine. Agnolucci et al. (2010) found that sulfur dioxide induces the VBNC state in 7 ''Brettanomyces'' strains isolated from wine at concentrations of 0.2 mg/L for 5 out of the 7 strains to 0.4 mg/L for the other 2 strains after 24 hours of incubation in a synthetic wine medium that was supplemented with various amounts of sulfur dioxide. At 0.4 mg/L they found that all but one strain had 0% culturable cells, and 4-26% VBNC cells depending on the strain. At 0.8 mg/L, no strains had culturable cells, but they all had at least 4.6-17% VBNC cells (percent of the original number of cells before being exposed to the sulfur dioxide). Even at 1 mg/L of sulfur dioxide levels, there were 2.9-15% VBNC cells, depending on the strain (the ability for the ''Brettanomyces'' to remain viable at 1mg/L of sulfur dioxide might have also been due to the pH only being 3.5, and ethanol only being 13%). They found that trypan blue was the best method for detecting VBNC cells. They also found that 2.1 mg/L was required to reduce the VBNC state of cells to zero after 55 days of incubation and limit the amount of ethyl phenols produced by ''Brettanomyces'' <ref>[https://www.sciencedirect.com/science/article/pii/S0168160510003958?via%3Dihub Sulphur dioxide affects culturability and volatile phenol production by Brettanomyces/Dekkera bruxellensis. Agnolucci M, Rea F, Sbrana C, Cristani C, Fracassetti D, Tirelli A, Nuti M. 2010. DOI: https://doi.org/10.1016/j.ijfoodmicro.2010.07.022.]</ref>.
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