Serratia Marcescens Lab Report 
Jeana Chun
Partners: Elizabeth Schwoerer, Amanda Shi
Honors Bio Period 4
Maloney
13 March 2015 Temperature And Its Effect On Gene Expression
Introduction
Gene expression, the process by which genotype is expressed as phenotype, is one of the most important biological functions living organisms are capable of carrying out. Although a cell may have thousands or hundreds of thousands of genes, only the ones needed this is determined by the environment are turned on at any given time. In bacteria, temperature, pH, and other chemical agents all affect the expression of genes. In this lab, the effect of temperature change on the gene which codes for a red pigment called prodigiosin of bacterium Serratia marcescens is being tested. Serratia marcescens is usually found in soil and plants, and the accumulation of prodigiosin in the bacterial cells makes them appear red. Prodigiosin is produced only at certain temperatures, so by regulating the temperature in which Serratia marcescens is cultured, the optimum temperature for the most prodigiosin to be produced can be tested. Purpose
The purpose of this lab is to observe the effect of temperature change on the production of the pigment prodigiosin by the bacterium Serratia marcescens, and also to determine whether previous culture conditions affect gene expression. Hypothesis
If the bacteria is cultured in 27
°C
, then it will produce more prodigiosin than the bacteria cultured in 37
°C
.
Regardless of the first culture conditions, the bacteria recultured in 27
°C
will produce more prodigiosin than the bacteria recultured in 37
°C
. Materials see attached lab, materials, page 25
Independent Variable: Temperature (in Celsius)
Dependent Variable: Amount of prodigiosin produced Methods/Procedures see attached lab, procedures, page 2527
Data see attached lab, data, page 25, 26 Analysis
1. You should label the bottom of a petri dish instead of the top because this
Partners: Elizabeth Schwoerer, Amanda Shi
Honors Bio Period 4
Maloney
13 March 2015 Temperature And Its Effect On Gene Expression
Introduction
Gene expression, the process by which genotype is expressed as phenotype, is one of the most important biological functions living organisms are capable of carrying out. Although a cell may have thousands or hundreds of thousands of genes, only the ones needed this is determined by the environment are turned on at any given time. In bacteria, temperature, pH, and other chemical agents all affect the expression of genes. In this lab, the effect of temperature change on the gene which codes for a red pigment called prodigiosin of bacterium Serratia marcescens is being tested. Serratia marcescens is usually found in soil and plants, and the accumulation of prodigiosin in the bacterial cells makes them appear red. Prodigiosin is produced only at certain temperatures, so by regulating the temperature in which Serratia marcescens is cultured, the optimum temperature for the most prodigiosin to be produced can be tested. Purpose
The purpose of this lab is to observe the effect of temperature change on the production of the pigment prodigiosin by the bacterium Serratia marcescens, and also to determine whether previous culture conditions affect gene expression. Hypothesis
If the bacteria is cultured in 27
°C
, then it will produce more prodigiosin than the bacteria cultured in 37
°C
.
Regardless of the first culture conditions, the bacteria recultured in 27
°C
will produce more prodigiosin than the bacteria recultured in 37
°C
. Materials see attached lab, materials, page 25
Independent Variable: Temperature (in Celsius)
Dependent Variable: Amount of prodigiosin produced Methods/Procedures see attached lab, procedures, page 2527
Data see attached lab, data, page 25, 26 Analysis
1. You should label the bottom of a petri dish instead of the top because this