Isolation and molecular identification of planctomycete bacteria from postlarvae of the giant tiger prawn, Penaeus monodon

Abstract

Bacteria phenotypically resembling members of the phylogenetically distinct planctomycete group of the domain Bacteria were isolated from postlarvae of the giant tiger prawn, Penaeus monodon. A selective medium designed in the light of planctomycete antibiotic resistance characteristics was used for this isolation. Planctomycetes were isolated from both healthy and monodon baculovirus-infected prawn postlarvae. The predominant colony type recovered from postlarvae regardless of viral infection status was nonpigmented. Other, less commonly observed types were pink or orange pigmented. A planctomycete-specific 16S rRNA-directed probe was designed and used to screen the isolates for their identity as planctomycetes prior to molecular phylogenetic characterization. 16S rRNA genes from nine prawn isolates together with two planctomycete reference strains (Planctomyces brasiliensis and Gemmata obscuriglobus) were sequenced and compared with reference sequences from the planctomycetes and other members of the domain Bacteria. Phylogenetic analyses and sequence signatures of the 16S rRNA genes demonstrated that the prawn isolates were members of the planctomycete group. Five representatives of the predominant nonpigmented colony type were members of the Pirellula group within the planctomycetes, as were three pink-pigmented colony type representatives. Homology values and tree topology indicated that representatives of the nonpigmented and pink-pigmented colony types formed two discrete clusters within the Pirellula group, not identical to any known Pirellula species. A sole representative of the orange colony type was a member of the Planctomyces group, virtually identical in 16S rDNA sequence to P. brasiliensis, and exhibited distinctive morphology.

Planctomycetes diversity associated with macroalgae

“…This has been isolated directly from Lagoa Vermelha, a salt pit sample from Brazil and described by Schlesner (1989). In addition, a closely related strain has been observed in the postlarvae of the giant tiger prawn, Penaeus monodon, Australia (Fuerst et al, 1997). Here, we enlarge the geographical regions of P. brasiliensis to the north Atlantic coast and the kind of habit to the biofilm community of macroalgae.…”

Patterns of bacterial diversity in the marine planktonic particulate matter continuum

“…In other contrasting environments, such as at 6000 m in the Puerto Rico Trench (Eloe et al, 2011) or in the Black Sea suboxic zone (Fuchsman et al, 2011) other groups were found in the ATT fraction, but Planctomycetes was always found enriched in particles. The phylum 'Planctomycetes' has been described as able to attach to surfaces (Bauld and Staley, 1976) such as macroalgae (Bengtsson and Øvreås, 2010;Lage and Bondoso, 2011), invertebrates (Fuerst et al, 1997) or macroscopic detrital aggregates (Delong et al, 1993;Crump et al, 1999), where they contribute to biopolymer degradation (Woebken et al, 2007). They were 43% of the communities of sizes 43 μm, but~1% in the smallest size-fractions ( Figure 3).…”

Spatial variability of marine bacterial and archaeal communities along the particulate matter continuum

“…Contrarily, Planctomycetes represent a group which is highly enriched in the larger particle size-fractions independent of depth (e.g., Crespo et al, 2013;Ganesh et al, 2014). Planctomycetes are known to be associated with distinct substrates (e.g., Bengtsson & Øvre as, 2010;Crump, Armbrust, & Baross, 1999;DeLong et al, 1993;Fuerst et al, 1997;Lage & Bondoso, 2011) where they likely contribute to biopolymer degradation (Woebken et al, 2007), which may explain their clear preference for larger particle size-fractions. On the other hand, groups like the Acidobacteria showed neither a preference for small nor large particles.…”