Inhibitory effect of bacterial ubiquinones on the settling of barnacle,Balanus amphitrite

Abstract

Abstract.In an attempt to clarify the influence of marine bacteria on the settling of fouling invertebrate larvae, we screened for inhibitors, produced by marine bacteria, of settling by cyprids of the barnacle, Balanus amphitrite. We found that the culture broth of Alteromonas sp. strain number KK10304, which was associated with the marine sponge, Halichondria okadai, effectively inhibited settling of the cyprids. Bioassay-guided isolation indicated ubiquinone-8 (1) as an effective inhibitor of cyprid settling. As ubiquinones are widely distributed in bacteria, several related compounds were also tested.Key words. Settlement inhibitor; barnacle; ubiquinone; sponge; Halichondria okadai; sponge associated bacteria; Alteromonas sp.Marine fouling invertebrates, such as barnacles and blue mussels, cause serious problems on ship hulls, in cooling systems of power plants, and in aquaculture systems. Organotin compounds such as TBTO [bis-(n-tributyltin)-oxide] have been used as effective antifouling agents against those organisms. However, stern warnings have been issued regarding the toxic effects of such heavymetal compounds on marine environments and wildlife, including fish and shellfish. Therefore, antifouling substances with no or reduced toxicity must be found and developed. In our screening for antifouling substances, using laboratory-reared larvae of the barnacle, Balanus amphitrite, we have reported fatty acids ~, steroids 1, a sesquiterpene hydrocarbon 2, a betaine 3, a furanoterpenoic acid 4, a pukalide derivative 4, a gramine derivative s and others as settling inhibitors in marine invertebrates. Crisp 7 reported that the larvae of fouling invertebrates were recruited to the settling surface in response to surface associated stimuli. He also revealed 7 that the stimuli played an important role not only in attracting larvae but also in inducing their metamorphosis. Mitchell and Kirchman s proposed that the stimuli were produced by bacteria growing on the solid surface. Maki et al. 9 reported that films of bacteria on solid substrate could positively or negatively influence the settling of marine invertebrate larvae. They 9 tested the effects of culture media of 18 different strains of marine bacteria on the settling of cyprids of the barnacle, B.amphitrite. They found that 8 out of 18 culture media showed inhibition of the settling and that the culture medium of Deleya (Pseudomonas) marina showed the strongest activity. These papers have suggested the existence of settling inhibitors produced by marine bacteria, although many of these compounds have remained unknown. In the present paper, we report the isolation and identification of the settling inhibitors from bacteria associated with a marine sponge. Materials and methods Isolation of bacteria.A common marine sponge, Ha[ichondria okadai, was collected from Numazu area in Suruga Bay of Shizuoka Prefecture, in 1990. This specimen was cut into small pieces (5 g), homogenized with 10 ml of sterilized seawater and diluted in a series of 10-fold dilutions. Each...

Identification and Characterization of a Putative Transcriptional Regulator Controlling the Expression of Fouling Inhibitors in Pseudoalteromonas tunicata

“…Many sessile algae and animals have evolved defense mechanisms against fouling by producing metabolites that can influence the settlement, growth and survival of other organisms (3,5,17,25). However, algae and animals lacking chemical defenses and nonchemical defenses such as surface sloughing are thought to rely on secondary metabolites produced by associated surface bacteria as their defense against fouling (14,18,29).…”

“…Many sessile algae and animals have evolved defense mechanisms against fouling by producing metabolites that can influence the settlement, growth and survival of other organisms (3,5,17,25). However, algae and animals lacking chemical defenses and nonchemical defenses such as surface sloughing are thought to rely on secondary metabolites produced by associated surface bacteria as their defense against fouling (14,18,29).The marine surface-associated bacterium Pseudoalteromonas tunicata strain D2 produces a number of stationary-phase, extracellular inhibitors that affect the normal settlement and growth of a variety of common marine fouling organisms. These include larvae from the invertebrates Ciona intestinalis and Balanus amphitrite, spores from the algae Ulva lactuca and Polysiphonia, various bacteria, and fungi (13).…”

Biofouling and Its Prevention: A Comprehensive Overview.

“…One of them is the search for naturally occurring antifouling compounds as an alternative for the toxic elements in the antifouling paints (Rittchof, 2000). Various aquatic organisms such as ascidians, corals, sponges, and algae have been screened for these compounds Gatenholm et al, 1995;Kon-Ya et al, 1995;Mizobushi et al, 1994;Tsukamoto et al, 1996). Even though only a few natural antifouling compounds are now available, their mass production to meet the demand seems to be uneconomical (Rittschof, 2000).…”

Surface bacterial community, fatty acid profile, and antifouling activity of two congeneric sponges from Hong Kong and the Bahamas

“…Numerous studies show potent antifeeding (Furrow et al 2003), allelopathic (Engel & Pawlik 2000), antifungal (Tsukamoto et al 1998), antibacterial (Thakur et al 2004), anti-microfouling (Amsler et al 2000), or anti-macrofouling (Kubanek et al 2002) activities in different species of marine sponges. There is growing evidence that some of these bioactive metabolites are of microbial origin (Kon-ya et al 1995), given the fact that sponges harbor a remarkable array of microorganisms, for instance, bacteria (Hentschel et al 2001), cyanobacteria (Thacker & Starnes 2003), and fungi (Maldonado et al 2005), both internally and on their surfaces. Through evolution, sponges may have developed a symbiotic relationship with certain kinds of microbes.…”