Antimicrobial activity of molluscan egg masses in the San Juan Islands, Washington


Meeting Abstract

P2.84  Wednesday, Jan. 5  Antimicrobial activity of molluscan egg masses in the San Juan Islands, Washington SMOOT, S.C.*; PLANTE, C.J.; PODOLSKY, R.D.; College of Charleston; College of Charleston; College of Charleston scsmoot@gmail.com

Gelatinous egg masses have evolved several times in invertebrates as a reproductive mode that encapsulates embryos until hatching. The absence of a hard outer covering makes these egg masses particularly susceptible to microbial infection, biofouling, and predation. The mucus and gel matrix surrounding the egg capsules may contain compounds that deter microbial infection. Furthermore, if adults can adjust the level of protection, then the amount of antimicrobial activity found within an egg mass should be correlated with the bacterial load found in the local environment. We are comparing the antimicrobial activity of egg masses among 15 molluscan species, among the components of egg masses (gel vs. embryos), and among sites where the sea slugs Haminoea vesicula and Melanochlamys diomedea are located. Egg masses were collected from the field, lyophilized and extracted with ethyl acetate and methanol to isolate non-polar and polar compounds. The extracts were then tested and quantified for antimicrobial activity against marine type cultures (Bacillus subtillis, Vibrio harveyi, and Pseudoaltermonas atlantica), as well as two environmental bacterial isolates, in a Burkholder petri dish and 96-well plate assay. We have observed antimicrobial activity in non-polar and polar extracts of Haminoea and Melanochlamys against Bacillus subtillis and Pseudoaltermonas atlantica, and are continuing with our other comparisons.

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