[57] Therefore, we hypothesised that the precipitation is due to decreased solubility possibly because of the high production rate and a change of the pH value of the medium during cocultivation. Supplementation of the agar with a pH indicator unveiled distinct pH differences after 7 days of cocultivation (Fig. 3B). Whereas we observed an alkaline
area on the bacterial side, the fungal culture resulted in an acidic medium. In the bacterial–fungal interface we thus have a change from alkaline to acidic pH value, which likely leads to the precipitation of bongkrekic acid. In conclusion, by a combined genomic and analytical-chemical approach we have shown that the bacteria associated with the food fermentation fungus R. microsporus possess a higher biosynthetic potential than previously believed. We demonstrated for the first time BAY 57-1293 cell line that B. gladioli is able to produce a class of potent antibiotics of the enacyloxin family and identified a novel analogue. This is especially important from a toxicological point of view as these compounds are also produced in the bacterial–fungal coculture implicating a potential production during the food fermentation process. Moreover, we
found that the fungus positively influences the growth of the bacteria in stationary culture, which results in an increased production of the lethal toxin bongkrekic selleck chemicals acid. In contrast, bongkrekic acid inhibits the growth of the
fungus. Thus, our findings not only highlight the importance of considering the biosynthetic potential of fungus-associated bacteria in terms of food safety but also demonstrate that Burkholderia species have long been underestimated as producers of natural products. This is especially Reverse transcriptase important as many Burkholderia species live in close association with Mucorales and thus may contribute to the effect these fungi exert on other organisms. We thank Karin Perlet for technical assistance in cultivation of microorganisms, Christiane Weigel for testing the antibacterial activity of enacyloxins and Andrea Perner, Tom Bretschneider and Heike Heinecke for MS, MALDI and NMR measurements, respectively. Financial support by the International Leibniz Research School (ILRS) for Microbial and Biomolecular Interactions as part of the excellence graduate school Jena School for Microbial Communication (JSMC) and the Pakt für Wissenschaft und Innovation is gratefully acknowledged. The authors declare no conflict of interest. “
“Surgery may improve the control of fungal disease and patient survival. The aim of this study was to report a single-centre experience in using surgery for the treatment of paediatric invasive fungal infection (IFI). From 2001 to 2009, 18 paediatric onco-haematology patients underwent 24 surgical procedures as treatment of IFI.