The free-living diazotroph Azotobacter vinelandii can fix nitrogen under aerobic conditions in the presence of reduced carbon sources such as sucrose or glycerol and is also known to produce a variety BMS-907351 concentration of siderophores to scavenge different metals from the environment. In this study, we identified two strains of green algae, Neochloris
oleoabundans and Scenedesmus sp. BA032, that are able to utilize the A. vinelandii siderophore azotobactin as a source of nitrogen to support growth. When grown in a co-culture, S. sp. BA032 and N. oleoabundans obtained the nitrogen required for growth through the association with A. vinelandii. These results, indicating a commensalistic relationship, provide a proof of concept for developing a mutualistic or symbiotic relationship between these two species using siderophores as a nitrogen shuttle and might further indicate an additional fate of siderophores in the environment. “
“Aspergillus fumigatus is often isolated from the lungs of cystic fibrosis (CF) patients, but unlike in severely immunocompromised individuals, the mortality rates are low. This suggests that competition from bacteria within the CF lung may be inhibitory. The purpose of this study was to investigate how Pseudomonas aeruginosa influences A. fumigatus Alectinib research buy conidial germination and biofilm formation. Aspergillus fumigatus biofilm find more formation was inhibited by
direct contact with P. aeruginosa, but
had no effect on preformed biofilm. A secreted heat-stable soluble factor was also shown to exhibit biofilm inhibition. Coculture of P. aeruginosa quorum-sensing mutants (PAO1:ΔLasI, PAO1:ΔLasR) did not significantly inhibit A. fumigatus biofilms (52.6–58.8%) to the same extent as that of the PA01 wild type (22.9–30.1%), both by direct and by indirect interaction (P<0.001). Planktonic and sessile inhibition assays with a series of short carbon chain molecules (decanol, decanoic acid and dodecanol) demonstrated that these molecules could both inhibit and disrupt biofilms in a concentration-dependent manner. Overall, this suggests that small diffusible and heat-stable molecules may be responsible for the competitive inhibition of filamentous fungal growth in polymicrobial environments such as the CF lung. The ubiquitous mould Aspergillus fumigatus is responsible for the majority of human infections caused by Aspergillus spp. The conidia produced by these saprophytic fungi disseminate by aerosolization and are inhaled, finally dwelling in the alveoli of human lungs (Askew, 2008). Aspergillus fumigatus can cause a range of opportunistic infections, ranging from allergic reactions (allergic bronchopulomary aspergillosis) to invasive disease, particularly in immunocompromised individuals, including cystic fibrosis (CF) patients (Skov et al., 2005). Persistent A.