Monitoring growth of the methanogenic archaea Methanobacterium formicicum using an electronic nose

Growth of the methanogenic archaea, Methanobacterium formicicum, in pure cu lture was monitored by analysing samples from the gas phase with an array o f chemical gas sensors (an 'electronic nose'). Analyses of the methane and protein formation rates were used as independent parameters of growth, and the data obtained from the electronic nose were evaluated using principal c omponent analysis (PCA). We found that different growth phases can be disti nguished with the electronic nose followed by PCA evaluation. The fast resp onse of the sensors in combination with the high correlations with other pa rameters measuring growth show that the electronic nose can be a useful too l to rapidly determine methanogenic growth.