Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics



Thesis Sponsor/Dissertation Chair/Project Chair

Lee H. Lee

Committee Member

John J. Gaynor

Committee Member

Robert W. Meredith


Cyanobacteria increased their attention after the breakthrough that they are responsible for the development of Freshwater Harmful Algal Blooms (FHAB). Cyanotoxins created by cyanobacteria impact aquatic biota and humans. Synechococcus sp. IU 625 [SIU 625) is one of the cyanobacteria that are blamable for the production of algal blooms. Due to its uncomplicatedness to culture, it has been used as a potential environmental pollution indicator, especially for heavy metal contamination.

Many EPA targeted metals such as Hg, Cd, Pb, Zn and Cu etc. have been considered. In this study, large plasmid was under investigation. Plasmid isolation of 5. IU 625 was carried and OligoPerfect™ Designer was used to design primers based on related S. elongatus PCC 7942 sequence. The PCR based assay was carried out and the PCR products were sequenced and assembled. The complete sequence of plasmid was achieved and indicated that plasmid in S. IU 625 has a high resemblance to the plasmid in S. elongatus PCC 7942.

In addition, stress responses of plasmid and chromosome were also studied using different concentrations of HgCh (0.1, 0.5 and 1.0 mg/L). The results suggest that there are Hg tolerant or resistant genes on the plasmid and chromosome to help the cells subsist in the stress setting.

File Format


Included in

Biology Commons