Planctomycetes and macroalgae, a striking association

Abstract

Planctomycetes are part of the complex microbial biofilm community of a wide range of macroalgae. Recently, some studies began to unveil the great diversity of Planctomycetes present in this microenvironment and the interactions between the two organisms. Culture dependent and independent methods revealed the existence of a great number of species but, so far, only less than 10 species have been isolated. Planctomycetes comprise the genera Rhodopirellula, Blastopirellula, and Planctomyces, Phycisphaera and the uncultured class OM190 and some other taxa have only been found in this association. Several factors favor the colonization of macroalgal surfaces by planctomycetes. Many species possess holdfasts for attachment. The macroalgae secrete various sulfated polysaccharides that are the substrate for the abundant sulfatases produced by planctomycetes. Specificity between planctomycetes and macroalgae seem to exist which may be related to the chemical nature of the polysaccharides produced by each macroalga. Furthermore, the peptidoglycan-free cell wall of planctomycetes allows them to resist the action of several antimicrobial compounds produced by the macroalgae or other bacteria in the biofilm community that are effective against biofouling by other microorganisms. Despite the increase in our knowledge on the successful planctomycetes-macroalgae association, a great effort to fully understand this interaction is needed.

Microbial Surface Colonization and Biofilm Development in Marine Environments

“…Numerous marine bacteria, especially those in the MRC group (8,272), the iron-oxidizing Betaproteobacteria and Zetaproteobacteria classes (586), the sulfur-oxidizing Beggiatoaceae and Leucotrichaceae families (587,588), morphotype IV of the Blastocaulis-Planctomyces group (14,589), and budding and prosthecate/ stalked bacteria such as the Hyphomonadaceae and Caulobacteraceae (590-592), produce a polar holdfast structure to facilitate surface colonization. Some other marine bacteria may also produce a holdfast, as indicated by their ability to form rosettelike aggregates, a characteristic associated with (though not shown to date to be directly connected to) holdfast production (593)(594)(595).…”

“…Other putative holdfast-producing bacteria are also frequently detected in marine surface-associated environments. For example, Planctomycetales colonize marine particles and algal or abiotic surfaces (12,14,(605)(606)(607), and sulfur-oxidizing, iron-corroding Leucotrichaceae colonize algal and submerged carbon steel surfaces (18, 608). Stalked or prosthecate Caulobacter and Hyphomonas bacteria are primary colonizers of algal or submerged surfaces (246,266,607).…”

“…Key genetic and ecophysiological processes and mechanisms that are fundamental to the life of marine bacteria on surfaces have been revealed. Some up-to-date reviews on marine biofilm-or particleassociated microorganisms are available (e.g., see references [8][9][10][11][12][13][14][15][16]). These reviews, albeit insightful, focus mostly on specific microbial groups, processes, functions, or colonizable substrata.…”

Intra- and inter-species interactions in microbial communities

“…Lage and Bondoso review the relatively understudied interactions between Planctomycetes and macroalgae in the context of complex microbial biofilms (Lage and Bondoso, 2014). Planctomcyetes share certain features with archaea, such as proteinaceous cell walls without peptidoglycan, and some distinctive characteristics with eukaryotes such as a complex system of endomembranes forming a unique cell plan.…”

Análise genômica e funcional da cianobactéria Nostoc sp. CENA67 e caracterização da sua comunidade microbiana associada

“…(MOULIN et al, 2001;PAWLOWSKI;SIRRENBERG, 2003;KRAUSE et al, 2006;ZAKHIA et al, 2006;MASSON-BOIVIN et al, 2009). Além disso, Phycisphaera pode estabelecer associações com algumas espécies de clorófitas (LAGE; BONDOSO, 2014). Rhodospirillum e Rhodopseudomonas também são capazes de realizar fotossíntese (GIESBERGER, 1947;LARIMER et al, 2004).…”