Exploring and Understanding of the Linkages between the Genomic and Chemical Profile of Tropical Cyanobacteria

Authors

Falguni Paul, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

<--Please Select Department-->

First Advisor's Name

Dr. Mauricio Rodriguez-Lanetty

First Advisor's Committee Title

Co-Committee Chair

Second Advisor's Name

Dr. Niclas Engene

Second Advisor's Committee Title

Co-Committee Chair

Third Advisor's Name

Ligia Collado Vides

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Dr. John Berry

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Dr. Kathleen Rein

Fifth Advisor's Committee Title

Committee Member

Sixth Advisor's Name

Dr. Miroslav Gantar

Sixth Advisor's Committee Title

Committee Member

Keywords

Cyanobacteria, secondary metabolites, chemotaxonomy, MALDI-TOF, microbiome, biosynthetic gene clusters, antiSMASH

Date of Defense

11-10-2022

Abstract

Many marine cyanobacteria create bioactive secondary metabolites that might be useful or harmful natural products (NPs). Although these metabolites are important ecologically and biomedically, many marine taxa have received minimal taxonomic study and have limited identification tools. The classical strategy relies on deceiving morphological traits. Cyanobacteria identification and taxonomy systems have increasingly relied on molecular methods. However, phylogenetic analysis is laborious.

My dissertation chapter 1 develops a fast and accurate chemotaxonomic method for cyanobacteria identification. This investigation sought species-specific main secondary metabolites quickly and precisely. To investigate, secondary metabolites profiling and 16S rRNA sequences of cyanobacteria from South Florida, the Caribbean, and Hawaii were compared. This work created and optimized a fast and reliable technique to identify tropical marine cyanobacteria using main chemical markers. My second chapter analyzed the microbiomes of chemically rich and non-chemically rich marine cyanobacteria and examined the relationship between NP production and microbiome diversity. 16S rRNA readings from environmental samples were obtained using high-throughput DNA sequencing. Annotating and comparing sequence reads revealed the complexity of microbial communities associated with chemically and non-chemically rich cyanobacteria. In this study, proteobacteria had the largest diversity. Alpha diversity showed that host-based bacteria were richer and more diverse. The microbiota and chemically rich specimens clustered in beta diversity. The third chapter covered NP production in a subtropical cyanobacteria. Illumina Miseq sequenced the Lyngbya strain 15-2 genome. The genome was constructed and annotated to test for pahayokolida A's biosynthetic gene cluster. Sequence data showed that the pathway is segmented and that Pah biosynthetase has 10 clusters that produce pahayokolida A. This study also found that Lyngbya strain 15-2 includes at least 27 gene clusters encoding secondary metabolite biosynthesis pathways, with NRPS projected to be the main one. My findings may help us understand the relationships between the microbiome and ecologically and biomedically relevant secondary metabolites, which could benefit drug developers and coastal habitats worldwide. Identifying the gene cluster would reveal the new biosynthetic mechanism behind a unique structure that could inspire biotechnological and medicinal uses.

Identifier

FIDC010881

Recommended Citation

Paul, Falguni, "Exploring and Understanding of the Linkages between the Genomic and Chemical Profile of Tropical Cyanobacteria" (2022). FIU Electronic Theses and Dissertations. 5192.
https://digitalcommons.fiu.edu/etd/5192