be integrated with the cellular regulation which occurs at the protein level (Langley
et al. 2013).
10.7.4 Metabolomics
Metabolomics is the analysis of the qualitative and quantitative aspects of all the
molecules with low molecular weight which are involved in the microbial metabolism. Those molecules are required for the maintenance, the growth, and the normal
function of the microbial population (Dunn and Ellis 2005; Goodacre et al. 2004; Lin
et al. 2006; Hettich et al. 2013; De Kok et al. 2013) (see Fig. 10.9).
10.7.5 MAR
Microautoradiography (MAR) uses radioactive isotopes to study the in situ uptake of
specific substrates (Talbot et al. 2008; Okabe et al. 2004; Ito et al. 2011, 2012). It is
an approach that allows to visualize and measure the uptake of the substrate by the
specific microbial populations and to visualize the organization of the community in
the space (Fig. 10.9).
Once the radioactively labeled substrate has been assumed by the microbia, the
researcher can monitor and visualize those bacteria and count them (Musat et al.
2011). Besides this if MAR is coupled to the fluorescence in situ hybridization
(FISH), this can permit to identify also the metabolically active microbial cells
(Musat et al. 2011).
10.8 Conclusions
This work describes in detail laboratory analytical methods to characterize the
inoculum and the substrate to be used in anaerobic digestion tests and also to perform
biomethanation potential tests and to measure biogas yields and methane yields. The
main analysis to fully characterize the inoculum and the substrate are the following:
sampling, storage, pH measurement, measurement of total solids and volatile solids,
measurement of chemical oxygen demand, measurement of nitrogen content, measurement of total organic carbon, measurement of trace elements and analysis of
phosphorous and sulfur content, measurement of alkalinity and volatile fatty acid
(VFA) concentrations, and measurement of fats, carbohydrates, and proteins. The
biomethanation potential tests have been highly discussed and standardized in the
literature. We present how to optimize the procedure, focusing on inoculum management, substrate management, and the test procedure itself. When performing
BMP tests, it is recommended to keep in mind what are the limitations of this kind of
10 Substrate Characterization in the Anaerobic Digestion Process
335
et al. 2013).
10.7.4 Metabolomics
Metabolomics is the analysis of the qualitative and quantitative aspects of all the
molecules with low molecular weight which are involved in the microbial metabolism. Those molecules are required for the maintenance, the growth, and the normal
function of the microbial population (Dunn and Ellis 2005; Goodacre et al. 2004; Lin
et al. 2006; Hettich et al. 2013; De Kok et al. 2013) (see Fig. 10.9).
10.7.5 MAR
Microautoradiography (MAR) uses radioactive isotopes to study the in situ uptake of
specific substrates (Talbot et al. 2008; Okabe et al. 2004; Ito et al. 2011, 2012). It is
an approach that allows to visualize and measure the uptake of the substrate by the
specific microbial populations and to visualize the organization of the community in
the space (Fig. 10.9).
Once the radioactively labeled substrate has been assumed by the microbia, the
researcher can monitor and visualize those bacteria and count them (Musat et al.
2011). Besides this if MAR is coupled to the fluorescence in situ hybridization
(FISH), this can permit to identify also the metabolically active microbial cells
(Musat et al. 2011).
10.8 Conclusions
This work describes in detail laboratory analytical methods to characterize the
inoculum and the substrate to be used in anaerobic digestion tests and also to perform
biomethanation potential tests and to measure biogas yields and methane yields. The
main analysis to fully characterize the inoculum and the substrate are the following:
sampling, storage, pH measurement, measurement of total solids and volatile solids,
measurement of chemical oxygen demand, measurement of nitrogen content, measurement of total organic carbon, measurement of trace elements and analysis of
phosphorous and sulfur content, measurement of alkalinity and volatile fatty acid
(VFA) concentrations, and measurement of fats, carbohydrates, and proteins. The
biomethanation potential tests have been highly discussed and standardized in the
literature. We present how to optimize the procedure, focusing on inoculum management, substrate management, and the test procedure itself. When performing
BMP tests, it is recommended to keep in mind what are the limitations of this kind of
10 Substrate Characterization in the Anaerobic Digestion Process
335