Fisheries and Wildlife 1100
9 April 2013
Do Bacteria Age?
Pamela Brown is an assistant professor of Biology here at the University of
Missouri Columbia. Her main area of study is bacteria, specifically on whether or not
they age. The main type of bacteria Professor Brown studies is called Agrobacterium
tumefaciens. It is a bacterium that reproduces asymmetrically and provides her with a lot
of information regarding whether bacteria actually age and the implications and/or
benefits that result from asymmetric reproduction.
She started the lecture by discussing the basics of microbiology in our world.
More than half of the Earth’s weight is made up of microbes and there are more microbial
cells in a human body than actual body cells. Additionally, microbes generate over half of
the Oxygen we breathe. Even though there are so many microbes around us and they are
usually looked at negatively, only fewer than five percent of them cause disease in plants,
animals, and humans. Bacteria can be bad because they cause disease, spoil food, and
cause biofouling. However, they are good for food production, digestion, bioremediation,
and they help plants grow.
The three shapes of bacteria are spherical, rodshaped, and spiral and their
exoskeletons are made up of Peptidoglycan. In order for the cell to grow, expansion of
the cell wall is required. The Aging Theory states that older individuals contribute fewer
offspring because they are less likely to divide. Historically bacteria have been Noto 2
considered immortal and that they were all “sibling cells,” not necess