Relevance of biofilm bacteria in modulating the larval metamorphosis of Balanus amphitrite

Abstract

Natural microbial communities found on different substrata exposed to the marine environment, including barnacle shell surfaces, are reported to have varying influences on the settlement and metamorphosis of competent cypris larvae. Experiments were carried out to compare the influence of settlement-inducing compounds from the bacteria isolated from the shell surface of Balanus amphitrite on its larval metamorphosis. The effect of multispecies bacterial film was also assessed. The production of different molecules by the bacteria was influenced by the nutrient media under which they were grown. It was observed that the promotory multispecies bacterial film turned to inhibition mode in the presence of the adult extract of the barnacle, indicating that bacteria-adult extract interactions alter the synthesis of different compounds produced by bacteria. The studies also show that the waterborne and the surface-associated cues from the bacteria function differentially in mediating larval metamorphosis. Understanding the complexities involved in such interactions and identification of the factors governing them would be a step forward.

Characterization of biofilm exudates and their effects on settlement of mussel (Perna canaliculus) larvae

“…Those results highlighted the importance of water soluble chemical cues as settlement inducers for P. canaliculus larvae. Studies with other marine invertebrate species have resulted in similar findings (Bao et al, 2007a;Fitt et al, 1990;Khandeparker et al, 2006;Neumann, 1979;O'Connor and Richardson, 1998;Satuito et al, 1997). In the present study, the settlement inducing fractions for P. canaliculus larvae were found to be of 1-3, 3-10 and 10-30 kDa for Macrococcus sp.…”

Role of conspecific cues and sugars in the settlement of cyprids of the barnacle, Balanus amphitrite

“…Barnacle cyprids other than their conspecifics also settle on the substrata that possess a well‐developed biofilm (Harder, Thiyagarajan & Qian, 2001; Khandeparker, Anil & Raghukumar, 2002 b , 2006). Bacteria produce surface‐bound and soluble chemical cues that either stimulate or inhibit larval settlement (Maki et al , 1990; Unabia & Hadfield, 1999; Qian et al , 2003; Dobretsov, Dahms & Qian, 2006).…”

Significance of biofilm proteins in modulating cyprid metamorphosis of Balanus amphitrite (Cirripedia: Thoracica)

“…A previous study by Khandeparker et al (2006) suggested that bacteria-adult extract interaction can alter the synthesis of compounds produced by bacteria. When the natural biofilm was assessed along with the adult extract the cyprid metamorphosis increased significantly.…”