Bringing Planctomycetes into pure culture.

Area of Science:

• Microbiology
• Environmental Science
• Bacteriology

Background:

• Planctomycetes, known since the early 20th century, encompass 11 genera and 5 candidate genera, including anammox bacteria.
• Environmental molecular studies indicate a much broader diversity of Planctomycetes than currently named species suggest.
• Previous molecular studies hinted at a significant relationship between Planctomycetes and macroalgae.

Purpose of the Study:

• To isolate and cultivate additional Planctomycetes strains from various environmental sources.
• To characterize novel Planctomycetes taxa and expand the collection of pure cultures.
• To provide culture-dependent evidence supporting the relationship between Planctomycetes and macroalgae.

Main Methods:

• Isolation and cultivation of Planctomycetes from freshwater sediments, marine fish farm recycling tank sediments, and macroalgae biofilms.
• Development and optimization of isolation methodologies for enhanced Planctomycetes recovery.
• Characterization of newly isolated strains, including novel taxa.

Main Results:

• Successful isolation of two freshwater strains, described as the new genus and species *Aquisphaera giovannonii*.
• Isolation of several *Rhodopirellula* strains from a marine fish farm environment.
• Obtained over 140 Planctomycetes isolates from macroalgae biofilms, including several novel taxa.

Conclusions:

• Culture-dependent methods confirm the intimate relationship between Planctomycetes and macroalgae.
• The study significantly expands the collection of isolated Planctomycetes, revealing novel taxa.
• Optimized isolation techniques enhance the recovery of diverse Planctomycetes from environmental samples.