Adsorption of Tolaasins, the Toxins Behind Mushroom Bacterial Blotch, by Microbacterium spp. is Insufficient for Its Detoxification

Insights into Detoxification of Tolaasins, the Toxins Behind Mushroom Bacterial Blotch, by Microbacterium foliorum NBRC 103072T

“…We previously reported that the ability to adsorb tolaasins is widely distributed among Microbacterium spp., but that tolaasin adsorption alone is insufficient for tolaasin detoxification (Tomita et al, 2020). Among the tested strains, we found that a few strains, including the bacterial isolate K3-5, showed significant tolaasin detoxification activity.…”

“…In the previous study, although only a few strains show tolaasin detoxification, we observed that effective tolaasin adsorption was widely distributed amongst Microbacterium Shun Tomita spp. (Tomita et al 2020), suggesting that the factor(s) responsible for tolaasin adsorption might exist independently from tolaasin detoxifying factor(s). Hence, in this study, we conducted a comparative study of tolaasin hydrolyzation and its elimination from bacterial cell suspensions and bacterial cell extracts (Fig.…”

“…Yang et al (2017) reported that the adsorption of a cationic lipopeptide, brevibacillin, to the cytoplasmic membrane of Staphylococcus aureus ATCC 6538, is inhibited by exogenous lipoteichoic acid (LTA), suggesting that an ionic interaction between brevibacillin and LTA has a key role on inhibiting the adsorption of a cationic lipopeptide to gram-positive bacterial cells. In our previous study, tolaasin I was extracted by 1M NaCl from tolaasin-treated bacterial cells of M. paraoxydans NBRC 103076 T which shows no tolaasin detoxification activity (Tomita et al 2020). Based on these findings, we deduced that LTA in the cell wall of Microbacterium spp.…”

“…When K3-5 detoxifies tolaasins, hydrolyzed tolaasins are released from K3-5 cells into the supernatant where they can be detected by LC-MS (Tomita et al 2018). On the other hand, although M. foliorum 103072 detoxifies tolaasins as well as K3-5, no hydrolyzed tolaasins can be detected in the M. foliorum 103072 supernatants (Tomita et al 2020), suggesting that the tolaasin-detoxification process by M. foliorum 103072-cells might differ from K3-5. Therefore, in this study we Page 6 of 38 Shun Tomita aimed to characterize the tolaasin-detoxification process of M. foliorum 103072.…”

“…efficiently adsorb tolaasins, whereas no tolaasin-detoxifying activity can be detected in their culture supernatants. However, tolaasin-adsorption onto Microbacterium cells is insufficient for tolaasin-detoxification by most of the strains (Tomita et al 2020).…”