Isolation and characterization of Sphingomonadaceae from fouled membranes

Abstract

Membrane filtration systems are widely applied for the production of clean drinking water. However, the accumulation of particles on synthetic membranes leads to fouling. Biological fouling (i.e., biofouling) of reverse osmosis and nanofiltration membranes is difficult to control by existing cleaning procedures. Improved strategies are therefore needed. The bacterial diversity on fouled membranes has been studied, especially to identify bacteria with specialized functions and to develop targeted approaches against these microbes. Previous studies have shown that Sphingomonadaceae are initial membrane colonizers that remain dominant while the biofilm develops. Here, we characterized 21 Sphingomonadaceae isolates, obtained from six different fouled membranes, to determine which physiological traits could contribute to colonization of membrane surfaces. Their growth conditions ranged from temperatures between 8 and 42 oC, salinity between 0.0 and 5.0% w/v NaCl, pH from 4 and 10, and all isolates were able to metabolize a wide range of substrates. The results presented here show that Sphingomonadaceae membrane isolates share many features that are uncommon for other members of the Sphingomonadaceae family: all membrane isolates are motile and their tolerance for different temperatures, salt concentrations, and pH is high. Although relative abundance is an indicator of fitness for a whole group, for the Sphingomonadaceae it does not reveal the specific physiological traits that are required for membrane colonization. This study, therefore, adds to more fundamental insights in membrane biofouling.

Spatial and temporal axes impact ecology of the gut microbiome in juvenile European lobster (Homarus gammarus)

“…The unclassified ESVs limited to the LBC system and assigned to Sphingomonadaceae and Saprospiraceae could both represent biofouling species derived from the recirculating system. Sphingomonadaceae, a family of Alphaproteobacteria, have been identified in the guts of oriental river prawn (Macrobrachium nipponense) [75] but also isolated from fouled membranes of water filtration systems [76], and Saprospiraceae, a family of Bacteroidetes, have been isolated from shrimp rearing water [77,78] and recirculating systems [79,80] likely explaining their association with hatchery individuals. The Sphingomonadaceae ESV was also identical to a sequence derived from the guts of reared N. norvegicus (JN092211) [45].…”

Genetic and physiological analysis of biofilm formation on different plastic surfaces by Sphingomonas sp. strain S2M10 reveals an essential function of sphingan biosynthesis

“…Flagella are also well-known as one important factor for biofilm formation in many bacteria, as they can act for example as adhesins [49] or mechanosensors [50]. Motility was also found to be a common feature in membrane-colonizing sphingomonads [14]. In agreement with that, Tn5 mutants Tn-fliF, Tn-flhA and Tn-FlaQ showed reduced swimming motility and reduced biofilm formation.…”

“…Interestingly, they are also frequently reported to occur in tap water [10] and drinking-water distribution systems [11]. There, they are typical biofilm-forming bacteria, especially on plastic membranes [12–14]. On reverse-osmosis membranes for drinking-water production, sphingomonads have been identified as the primary colonizers [15], and they are frequently found on high-pressure membrane filtration systems in general [16].…”

Phosphorus Source and Availability Modulate the Rhizosphere Bacterial Community Assembly in Common Bean

“…2a,b) an increase in the phyla Alphaproteobacteria (Sphingomonadaceae) and Bacteroidetes (Chitinophagaceae). The family Sphingomonadaceae was described to be pioneers colonizers of bio lms [43,44], suggesting a oligotrophic life strategy, also, a genus of this family was described to promote plant growth in endophytic conditions . Its role in P cycle occurs since the regulation, mobilization and acquisition in soil amended with nitrogen and organic matter [42].…”