Guide

Main Module | Energy from Mud? Thank a Microbe!
14
Background
backGrouNd
WhatareMicrobialFuelCells?
Microbial fuel cells (MFCs) generate electricity
using the natural ability of microbes to produce
electrical power when they process food. To
understand this process we need to understand
how microbes get their energy.
All living organisms need energy to live but where
does that energy come from?
Theenergyorganismsneedtolivecomesfromtheenergystored
inthe“foods”theyeat.
Some organisms, such as plants and some bacteria,
make their own food. Other organisms must eat
preexisting organic matter to get their energy.
To release the energy stored in the chemical bonds
of the food organisms metabolize, which means
they use a series of chemical reaction to release
the energy stored in the chemical bonds of the
food they eat. Organisms differ in the way that
they metabolize but the end result is the same:
food is broken down and the stored energy is
converted into energy that the organisms can use to grow, repair and reproduce in a
process called cellular respiration.
Respiration is a very complex process but what
is important to understand is that ALL organisms
respire, and during respiration, electrons are
given off in a series of chain reactions.
These electrons get picked up by an “electron acceptor” and are used in another
series of chemical reaction. For humans, and many other animals and certain
bacteria, oxygen is the electron acceptor.
When oxygen is the electron acceptor the
process is called aerobic respiration and the
organisms that metabolize using oxygen are
called aerobes.
You need microbes to make a
microbial fuel cell work!
All organisms get their energy
from the food they eat!
StudeNt haNdout
BiologyConnection!
The reason we breathe is to
get oxygen to use in cellular
respiration!
ExtensionIdea!
Want to see what different types
of bacteria use for food? Make a
WinogradskyColumn!