The descriptive name given to a microorganism that can grow in conditions where oxygen is present.
Many aerobes are equally able to grow in the absence of oxygen.
These are termed facultative anaerobes. A microorganism that is capable of growing in the complete absence of oxygen. Such organisms are termed obligate anaerobes. The time taken for a population to increase in number by a factor of two. Usually the toxin has specific targets and either disrupts cell function or kills the cell.