Jonathan Knight and Richard Gregory MB 495 November 28, 2011 Effects of Glucose Concentration on the growth of Pseudomonas fluorescens Jonathan Knight and Richard Gregory MB 495 November 28, 2011

Original Hypothesis High concentrations of glucose in the LB media are enabling biphasic growth.

Experiment 3 Note: the different lag times between .5 and 2% glucose

Second try…experiment 5 Note: no biphasic growth, long lag times, and lower max OD’s with higher conc. Of glucose and smaller concentrations of LB.

In graph form…

New Hypothesis… Pseudomonas fluorescens can survive high osmostic pressure from high glucose concentrations, however, it must adjust through regulation of it’s genes.

Constant LB and Varying Glucose (experiment 7)

Conclusions Pseudomonas fluorescens can survive more osmotic pressure than previously believed. The biphasic growth was not reproducible. High glucose concentrations increased lag times, indicating some sort of regulatory changes that must be done in order for the organism to survive. Restricting LB media, decreased maximum populations of organism, proving that the organism cannot make it’s some amino acids and vitamins…. Continuing research should be done on the molecular level to see what actually enables this organism to live at such extreme osmotic pressure.