Date of Award

Spring 5-10-2014

Degree Type



Chemistry and Biochemistry

Director of Thesis

Bert Ely

First Reader

Latia Scott


Caulobacter segnis is a unique species of Caulobacter in that it is slow growing, found in soil samples, and has other phenotypic differences from the freshwater Caulobacter that it is most closely related to. Initially deemed Mycoplana segnis, it was reclassified after a 16s rRNA analysis and found to be most closely related to the Caulobacter NA1000 branch. Because the annotated sequence available in GenBank contained a large number of pseudogenes (126), we compared the original sequencing data to the GenBank sequence and determined that many of the pseudogenes were due to sequence errors in the Genbank sequence. Consequently, we used multiple approaches to correct and reannotate the C. segnis genome sequence. In total there were 247 nucleotide deletions, 14 insertions, and 8 substitutions resulting in 233 fewer bases in our corrected sequence. The corrected sequence contains only 27 pseudogenes compared to the 126 of the original annotation. Furthermore it was found that C. segnis does produce prosthecae when grown in low nutrient conditions and the swarmer cells have a single, polar flagellum not peritrichous flagella. In addition we confirmed that Riboflavin is essential for growth. At 30°C C.segnis had a doubling time of 200 minutes and it was also able to grow slowly at 4°C.