17 to 30 minutes http://textbookofbacteriology.net/growth_3.html http://textbookofbacteriology.net/growth_3.html http://textbookofbacteriology.net/growth_3.html http://textbookofbacteriology.net/growth_3.html http://textbookofbacteriology.net/growth_3.html http://textbookofbacteriology.net/growth_3.html