gate voltage to probe the mechanism of conductivity in biofilms. The simple method
described here to measure electronic conductivity of living biofilms is expected to be
a useful tool for future studies of long-range electron conduction in a diversity of
microbial systems such that those in sediments and anaerobic digesters.
5.4
Microbial Growth and Death
In microbial electrochemical cells (MXCs), not only classic over potentials known
from other types of fuel cells are encountered, but also over potentials associated
with the metabolic processes and electron transport pathways in bacteria are encountered. Of the many techniques that can be used to investigate the contributions of
various processes to the total over potential in MXCs, this chapter focuses on
electrochemical impedance spectroscopy (EIS). This technique is an alternating
current technique that involves applying sinusoidal voltage amplitude over a range
of frequencies to investigate the processes that control the overall i–V response. The
use of EIS allows differentiating these various processes, as they are often
manifested at different frequencies. We discuss the principles and theory behind
EIS, especially with respect to its use in MXCs, as well as important experimental
methods and design parameters (Dominguez-Benetton et al. 2012). We show that
EIS is an important method that can be used to characterize Ohmic resistance,
electrode processes, or an MXC as a whole.
5.5
Conclusion
In the anodic chamber of MFCs, initially, the mixed culture is inoculated from
existing anaerobic sludge collected from wastewater treatment. This anaerobic
sludge containing anaerobic mixed bacteria and these are responsible for organic
removal from the wastewater. In the anodic chamber, they worked in MFC mode and
electroactive microbes are accumulated and these electroactive bacteria make biofilm on the anode electrode. So to reduce the lag phase of these microbes, it is
recommended that, for a new MFC, starting inoculums should be used from the
pre-running MFC. In the biocathodic MFC, denitrifier bacteria are added in the
cathodic chamber and anaerobic electroactive bacteria in the anodic chamber of
MFC. The electroactive bacteria present in the BES reactor is responsible for its
better performance and efficiency for wastewater treatment and bioelectricity
generation.
5 Microbiology of Bioelectrochemical System
111
described here to measure electronic conductivity of living biofilms is expected to be
a useful tool for future studies of long-range electron conduction in a diversity of
microbial systems such that those in sediments and anaerobic digesters.
5.4
Microbial Growth and Death
In microbial electrochemical cells (MXCs), not only classic over potentials known
from other types of fuel cells are encountered, but also over potentials associated
with the metabolic processes and electron transport pathways in bacteria are encountered. Of the many techniques that can be used to investigate the contributions of
various processes to the total over potential in MXCs, this chapter focuses on
electrochemical impedance spectroscopy (EIS). This technique is an alternating
current technique that involves applying sinusoidal voltage amplitude over a range
of frequencies to investigate the processes that control the overall i–V response. The
use of EIS allows differentiating these various processes, as they are often
manifested at different frequencies. We discuss the principles and theory behind
EIS, especially with respect to its use in MXCs, as well as important experimental
methods and design parameters (Dominguez-Benetton et al. 2012). We show that
EIS is an important method that can be used to characterize Ohmic resistance,
electrode processes, or an MXC as a whole.
5.5
Conclusion
In the anodic chamber of MFCs, initially, the mixed culture is inoculated from
existing anaerobic sludge collected from wastewater treatment. This anaerobic
sludge containing anaerobic mixed bacteria and these are responsible for organic
removal from the wastewater. In the anodic chamber, they worked in MFC mode and
electroactive microbes are accumulated and these electroactive bacteria make biofilm on the anode electrode. So to reduce the lag phase of these microbes, it is
recommended that, for a new MFC, starting inoculums should be used from the
pre-running MFC. In the biocathodic MFC, denitrifier bacteria are added in the
cathodic chamber and anaerobic electroactive bacteria in the anodic chamber of
MFC. The electroactive bacteria present in the BES reactor is responsible for its
better performance and efficiency for wastewater treatment and bioelectricity
generation.
5 Microbiology of Bioelectrochemical System
111