Meeting Abstract

29.3  Friday, Jan. 4  Interactions between biofilm bacteria and barnacles Balanus amphitrite ESSOCK-BURNS, T.*; TARRELL, A.; MATHAI, P.; GOHAD, N.V.; MOUNT, A.S.; MAKI, J.S.; RITTSCHOF, D.; Duke University; Marquette University; Marquette University; Clemson University; Clemson University; Marquette University; Duke University te18@duke.edu

Biofilms are associated with macrofouling organisms. We are interested in the interactions between bacterial communities and barnacles. Here, we report results bacteria-barnacle associations of larval stages, colonization of primary attachment of glue by bacteria, what happens to bacterial communities under juvenile barnacles as they grow, and experimental studies of bacterial communities associated with adult barnacles attached to dialysis membranes. Finally, direct contact tests using glue and bacteria isolated from surfaces. Barnacle nauplii and cyprids collected from the plankton no evidence of bacteria using epifluorescent microscopy and bacterial staining techniques. The same technique showed bacteria on the surface barnacle cyprid primary attachment glue. Bacteria are found under the base of 6-day old juvenile barnacles. By 14 days there are no bacteria present under the barnacles. Late juvenile barnacles were reattached to sheets of cellulose dialysis membrane and grown for 1-2 months. Denaturing Gradient Gel electrophoresis data show different bacterial composition of biofilms under barnacles than exposed biofilms on the membranes. Based on these results, we explored the interaction between bacteria isolated from surfaces and fresh barnacle glue in direct contact tests. Two major findings from the direct contact test are: 1) growth was stimulated by glue in bacteria grown in low and high nutrients and 2) bacterial growth in high nutrient conditions was unexpected and suggests hormesis. Our results suggest, the symbiosis between barnacles and bacterial communities is complex and may involve active management by barnacles.