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BARS 2020, Research

Identification and characterization of marine bacteria associated with Lytechinus variegatus

Name: Joonsuk Yang, Zameena Bhairo

Mentor: Lalitha Jayant

Abstract: A diversity of bacteria share symbiotic relationships with sessile marine invertebrates. These dependent microbiota prove to be potential producers of known and novel secondary metabolites. This study focuses on identifying and characterizing bacterial flora that exist on the tests and orifices of the sea urchin species, Lytechinus Variegatus. The external surfaces of sea urchins were swabbed and plated onto marine agar plates for bacterial isolation. Fourteen of the initial samples were chosen for identification and characterization. The bacterial samples selected were gram negative rods, oxidase positive, did not ferment sucrose and had no antibacterial properties. The Kerry-Bauer tests revealed that the bacterial samples are resistant to common and rare antibiotics used in medicine. Some of the isolated bacteria harbor endogenous cryptic plasmids of around 20 Kbp. One of the isolated bacteria was agarolytic in nature. Only a few bacteria were active when cultured on starch and cellulose plates. Chromosomal DNA of all the samples were isolated, and the bacterial genome was subjected to 500bp conserved 16S rRNA PCR. Purified PCR products were subjected to forward and reverse sequencing reactions. Current biochemical analysis determines the bacterial strains to be of the genus Pseudomonas. Future studies involve analyzing the raw DNA sequencing data using the bioinformatics software QIIME for taxonomic assignment, phylogenetic reconstruction, and diversity analysis and visualization. Additional antimicrobial assays and biochemical tests will determine potential antimicrobial properties against other microorganisms, as well as notable biochemical activities.

1 Comment

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