@misc{BreitenbachGerritsDementyevaetal., author = {Breitenbach, Romy and Gerrits, Ruben and Dementyeva, Polina and Knabe, Nicole and Schumacher, Julia and Feldmann, Ines and Radnik, J{\"o}rg and Ryo, Masahiro and Gorbushina, Anna A.}, title = {The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering}, series = {npj Materials Degradation}, volume = {6}, journal = {npj Materials Degradation}, number = {1}, publisher = {Nature Publishing Group UK}, issn = {2397-2106}, doi = {10.1038/s41529-022-00253-1}, pages = {11}, abstract = {The roles extracellular polymeric substances (EPS) play in mineral attachment and weathering were studied using genetically modified biofilms of the rock-inhabiting fungus Knufia petricola strain A95. Mutants deficient in melanin and/or carotenoid synthesis were grown as air-exposed biofilms. Extracted EPS were quantified and characterised using a combination of analytical techniques. The absence of melanin affected the quantity and composition of the produced EPS: mutants no longer able to form melanin synthesised more EPS containing fewer pullulan-related glycosidic linkages. Moreover, the melanin-producing strains attached more strongly to the mineral olivine and dissolved it at a higher rate. We hypothesise that the pullulan-related linkages, with their known adhesion functionality, enable fungal attachment and weathering. The released phenolic intermediates of melanin synthesis in the Δ sdh1 mutant might play a role similar to Fe-chelating siderophores, driving olivine dissolution even further. These data demonstrate the need for careful compositional and quantitative analyses of biofilm-created microenvironments.}, language = {en} }