Cultivating anaerobic bacteria in aerobic conditions

How you ever asked yourself how do we get anaerobic bacteria in our guts? This is not so trivial question, since these anaerobes we get from different sorts of food and therefore, they must travel through aerobic condition before they settle inside our guts. The solution for this problem might be in formation of aggregates where outer microbes are consuming oxygen and forming anaerobic niches inside such aggregates. This is something that hypothetically can happen in nature, but how can we make such structures in the laboratory. Here we applied the methods used in colloid biology that allow us to join together different types of bacteria in synthetic 3D structures like aggregates (Tatenhove-Pel et al., 2021) and biofilms (Rijavec et al., 2019) – fig 1 and 2. This approach enables growing anaerobic bacteria, here sulfate reducing bacteria (SRB), in flasks on a shaker at aerobic fully oxidized conditions (see formed black precipitate as a prove of growth of SRBs in fig 3).

Using our synthetic structures we can increase efficiency of biologically aided precipitation of toxic metals in remediation processes aiming water clean-up, processes which are currently only efficient under anaerobic conditions. Moreover, this innovative approach of cultivation of anaerobes can also aid other biotechnological processes including biogas and butanol production as well as optimisation of microbial fuel cells.