Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology


The genes for Assimilatory Nitrate and Nitrite Reductase are called nasA and nasB in most organisms. Some of the regulatory genes for the nasAB operon are nasR, and a presumptive nasST. In this study an attempt was made to amplify, clone and sequence the nasST operon in the organism Azospirillum brasi/ense by using primers from a closely related species, Azotobacter vinelandii, in the polymerase chain reaction. The pieces of DNA that were amplified using these primers were cloned using the TA cloning method. Clones with the target inserts were sequenced by automated sequencing. The sequences were analyzed using a program called Gene Jockey. The complete sequences were compared to other nucleotide and peptide sequences at genbank in the Blast database. The matching sequences were identified and the inserts were characterized bases on the comparisons at Blast. After comparison of the sequences is was determined that the DNAs were most likely not nasST. The results were several enzymes and regulatory proteins that corresponded with the 1 .0 kb piece of cloned DNA such as the SohA protein of E. coli (99% probability), an aldolase enzyme of Pseudomonas species (99% probability), the mosA gene product of Rhizobium meliloti (99% probability), the dihydropicolinate synthase of Bacillus subtilis (99% probability), Corynebacterium glutanicum (99% probability), and E. coli (19% probability).

Library of Congress Subject Headings

Azospirillum Bacterial genetics Molecular cloning Nitrogen cycle



Number of Pages



South Dakota State University