Comparing Growth of E. Coli at 37°C and 25°C and on rich and minimal mediums

Lab report 1

Richard Montez

MCB 3020L Monday 2 pm

June 15, 2013

Abstract:

Bacteria is a very diverse creature, and can grow in extreme conditions. There are two variables that factor in finding out what are more optimal conditions in which E. coli can grow, temperature and difference in medium. The two ways to determine the amount of bacteria growth are: optical density by using the spectrophotometer, and also the 10-fold serial dilution, the latter of which is the most accurate way. The 4 phases: lag phase, log phase, stationary phase and death phase, show the strength of the life cycle of a bacteria cell. The results show that at 37°C (normal body temperature) and the LB agar plate (rich medium) gives E. coli better optimal conditions to grow.

Introduction
Although bacteria is composed of only a single cell, they are extremely involved and we have so much to learn about these creatures. Bacteria can live in some of the most extreme temperatures- from temperatures that could potentially freeze the blood under your skin, to the other end of the spectrum where they could be found at temperatures near 100°C at the mid-ocean volcanic vents. The bacteria we chose to further learn about it's optimal growth conditions was Escherichia Coli. There are two variables in this experiment, temperature and choice of medium. The first variable, the sample was incubated E. Coli at 25°C, which is considered room temperature, and also 37°C which is considered the average body temperature. Agar was the solidifying agent for the mediums. The other variable was the choice of medium to grow on. The E. coli sample was incubated at 37C on a rich medium, Luria Broth agar plate (LBS), and also a minimal medium, a glucose minimal salt agar plate (GMS) to see what medium was more