Abstract: The invention relates to a method for extracting oxygen form a reaction chamber, as well as a use of microorganisms in such a method and a photobioreactor for carrying out the method. According to the invention, the method comprises the steps—irradiating at least one phototropic microorganism with light under anaerobic conditions in a reaction chamber, and—in situ bonding of produced oxygen by means of the microorganism by oxidation of an oxygen-utilizing substrates.

Abstract: A composition of microorganisms, comprising photoautotrophic microorganisms (16) which produce oxygen by photosynthetic water oxidation chemoheterotrophic microorganisms (17) which respire oxygen, wherein the photoautotrophic microorganisms (16) and the chemoheterotrophic microorganisms (17) are comprised in a biofilm (13), the biofilm further comprising components (15) which were secreted by the photoautotrophic microorganisms (16) and/or the chemoheterotrophic microorganisms (17), and a reactor (1), a method for forming a biofilm, and a method for biocatalytic conversion employing such composition.