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Analysis of Cyclodipeptide Biosynthetic Genes in Nocardiopsis alba ATCC BAA-2165

Li, Yongli
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1397232633

Abstract Details

2014, Master of Science (MS), Ohio University, Biological Sciences (Arts and Sciences).
Nocardiopsis alba ATCC BAA-2165 is an actinobacterium isolated from honeybee guts in Southern Ohio. It was reported N. alba showed antibiotic activity against several Gram-positive microorganisms, including two honeybee pathogens. Bioactivity-guided compound isolation led to an identification of two cyclodipeptides, albonoursin (cyclo(ΔPhe-ΔLeu)) and its analog (cyclo(mΔTyr-ΔLeu)), as the bioactive metabolites produced by N. alba. Despite its important environmental presence, characterization of the Nocardiopsis genus was limited due to the lack of genetic tools. In this project, we focused on the cyclodipeptides production of N. alba to establish a system for genetic analysis of Nocardiopsis. An albonoursin cyclodipeptide biosynthetic gene cluster, albABC, was identified in the N. alba genome. A PCR-targeting strategy was developed to generate an albABC deletion mutant of N. alba; the mutant, YL001, was shown to have lost the production of cyclodipeptides. Cyclodipeptides production in YL001 was restored by genetic complementation with the albABC cloned in a replicative native plasmid of Nocardiopsis. These results indicate that the albABC biosynthetic genes are responsible for the production of antibiotic cyclodipeptides of N. alba. Two additional mutants, in which a reporter gene gusA encoding ß-Glucuronidase (GUS) is fused to albABC promoter in chromosome, were created to measure the transcriptional activity of the albABC genetic operon. With the GUS reporter assay, albABC gene expression was found to be possibly controlled in response to osmolarity of the growth environment. A series of molecular microbiological methods have been developed for N. alba, which lays the foundation for further characterization of Nocardiopsis actinobacteria on a genetic basis.
Shawn Chen (Advisor)
126 p.
Biology
Nocardiopsis alba; Cyclodipeptides; Biosynthesis

Recommended Citations

Citations

  • Li, Y. (2014). Analysis of Cyclodipeptide Biosynthetic Genes in Nocardiopsis alba ATCC BAA-2165 [Master's thesis, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1397232633

    APA Style (7th edition)

  • Li, Yongli. Analysis of Cyclodipeptide Biosynthetic Genes in Nocardiopsis alba ATCC BAA-2165 . 2014. Ohio University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1397232633.

    MLA Style (8th edition)

  • Li, Yongli. "Analysis of Cyclodipeptide Biosynthetic Genes in Nocardiopsis alba ATCC BAA-2165 ." Master's thesis, Ohio University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1397232633

    Chicago Manual of Style (17th edition)

ohiou1397232633
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© 2014, all rights reserved.
This open access ETD is published by Ohio University and OhioLINK.