DOI: 10.5061/dryad.c3b75
title: Data from: Investigating a possible role for the bacterial signal molecules N-acylhomoserine lactones in Balanus improvisus cyprid settlement

description: Increased settlement on bacterial biofilms has been demonstrated for a
 number of marine invertebrate larvae, but the nature of the cue(s)
 responsible is not well understood. We tested the hypothesis that the bay
 barnacle Balanus improvisus utilises the bacterial signal molecules
 N-acylhomoserine lactones (AHLs) as a cue for the selection of sites for
 permanent attachment. Single species biofilms of the AHL-producing
 bacteria Vibrio anguillarum, Aeromonas hydrophila and Sulfitobacter sp.
 BR1 were attractive to settling cypris larvae of Balanus improvisus.
 However, when AHL production was inactivated, either by mutation of the
 AHL synthetic genes or by expression of an AHL-degrading gene (aiiA), the
 ability of the bacteria to attract cyprids was abolished. In addition,
 cyprids actively explored biofilms of E. coli expressing recombinant AHL
 synthase genes, but not on E. coli that did not produce AHLs. Finally,
 concentrations of synthetic AHLs similar to those found within natural
 biofilms (5 µM) resulted in increased cyprid settlement. Thus, the
 attraction of B. improvisus larvae to biofilms appears to be mediated by
 AHL signalling bacteria in the laboratory. This adds to our understanding
 of how quorum sensing inhibition may be used as a means of biofouling
 control. Nonetheless, the significance of our results for larvae settling
 naturally in the field, and the mechanisms that underlay the observed
 responses to AHLs, are as yet unknown.
description: Tait and Havenhand
 Biofilm dataBiofilms data.txt: This
 data records the number of Balanus improvisus cyprids exploring (Day 2
 data only) and the number of cyprids settled (Days 3 to 7 data) on
 biofilms of signal-producing and signal-deficient biofilms. Biofilms
 either had mutations to their AHL synthase gene or were expressing the
 recombinant AHL inactivation protein AiiA. The biofilms were: Vibrio
 anguillarum NB10, a vanM mutant of this strain, and a variant expressing
 aiiA; A. hydrophila and an ahylI mutant and Sulfitobacter sp. BR1 and a
 sulI mutant. Each experiment also contained no biofilm controls.
 Experiments with V. anguillarum were conducted with 3 batches of cyprids,
 Sulfitobacter BR1 with 2 batches of cyprids and A. hydrophila with 1 batch
 of cyprids. This data was recorded by Karen Tait, Plymouth Marine
 Laboratory (ktait@pml.ac.uk) at the Department of Biological and
 Environmental Sciences, Tjarno, Sweden in June 2009. Column headings: V.
 anguillarum Batch 1; V. anguillarum Batch 2; V. anguillarum Batch 3; A.
 hydrophila Batch 1; Sulfitobacter Batch 1; Sulfitobacter Batch 2.
 Sub-headings: Biofilm Type (WT, mutant or no biofilm); Vessel No.; Day 2
 (percent number of cyprids actively exploring biofilm); Day 3 (percent
 number of cyprids settled); Day 4 (percent number of cyprids settled); Day
 5 (percent number of cyprids settled); Day 6 (percent number of cyprids
 settled); Day 7 (percent number of cyprids settled). Mutant biofilm
 descriptions are as follows: vanM – V. anguillarum, mutation to the AHL
 synthase, vanM; aiiA – V. anguillarum expressing the AHL degradation
 protein AiiA; ahyI – A. hydrophila, mutation to the AHL synthase, ahyl;
 sulI – Sulfitobacter BR1, mutation to the AHL synthase,
 sulI.Tait and Havenhand E.
 coli dataE. coli data.txt: This
 data records the number of Balanus improvisus cyprids exploring biofilms
 of E. coli expressing recombinant AHL synthases after 2 days incubation.
 For each AHL synthase gene, this is compared to a background control (E.
 coli carrying the same plasmid without the AHL synthase insertion). Data
 is the percent number of cyprids actively exploring (crawling) on the
 biofilms. This data was recorded by Karen Tait, Plymouth Marine Laboratory
 (ktait@pml.ac.uk) at the Department of Biological and Environmental
 Sciences, Tjarno, Sweden in June 2009. Column headings: Vessel number
 (numbered 1 – 21); no biofilm (vessel contained no biofilm); E. coli pGEM
 (control biofilm); E. coli pGEM sulI (produces the AHLs C4-HSL, HC6-HSL,
 C8-HSL and OC10-HSL); E. coli pT3T7 (control biofilm); E. coli pT3T7 luxI
 (produces the AHL OC6-HSL); E. coli pUCP18 (control biofilm); E. coli
 pUCP18 rhlI (produces the AHL C4-HSL); E. coli pET3a (control biofilm); E.
 coli pET3a vanI (produces the AHL OC10-HSL).Tait and Havenhand
 Synthetic AHL dataSynthetic AHL data.txt:
 This data records the number of Balanus improvisus cyprids exploring
 agarose films containing 5 µM C6-HSL, C8-HSL, OC10-HSL and C12-HSL after 2
 days incubation. Data is the percent number of cyprids actively exploring
 (crawling) on the biofilms. Also recorded is the numbers of cyprids
 settled within vessels containing the same synthetic AHLs dissolved in
 seawater to the following concentrations: 0.5, 5 and 50 µM. Data is the
 percent number of cyprids settled within the vessels. This data was
 recorded by Karen Tait, Plymouth Marine Laboratory (ktait@pml.ac.uk) at
 the Department of Biological and Environmental Sciences, Tjarno, Sweden in
 June 2009. Column headings: Synthetic AHL in agarose film; Vessel number
 (numbered 1 – 18); C6; C8; OC10; C12; no AHL. Synthetic AHL in seawater;
 AHL concentration (0, 0.5, 5 or 50 µM); Vessel number (numbered 1 – 21 for
 each treatment); C6; C8; OC10; C12.