We gratefully acknowledge the financial support provided by the Spanish Ministry of Economy and Competitiveness (Projects CSD2007-00005, BIO2010-16303 and BIO2011-25012) and the European Regional Development Fund (ERDF). Partial support by the FP7-KBBE program through the projects Microme (Grant No. 222886-2) and MAGICPAH (FP7-KBBE-2009-245226) is also gratefully acknowledged. Proteomics analysis performed in the ONJ laboratory was supported by a research grant (FNU 09-072287) and an EliteForsk award to ONJ from the Danish Council for Independent Research. CMG thanks the Spanish Ministry of Economy and Competitiveness for a PhD fellowship. We thank Professor Antonio M Gil Serrano, Departamento de Química Orgánica, Universidad de Sevilla (Spain) for the analysis of sugar composition of B1 and B2 macroscopic growths. We also thank Professor Peter Golyshin and Dr Michail Yakimov for their excellent support in relation to the critical revision of the manuscript and the analysis of metabolic capacities, respectively.