Bacterial Community Succession in Natural River Biofilm Assemblages

Abstract

Temporal bacterial community changes in river biofilms were studied using 16S rRNA gene-based polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) followed by sequence analysis. Naturally occurring biofilms were sampled in 2001 during an undisturbed 7-month low-water period in the River Garonne (SW France). During the sampling period epilithic biomass exhibited a particular pattern: two 3-month periods of accumulation that resulted in two peaks in summer and fall, each at about 25 g ash-free dry mass per square meter. Bacterial community DGGE profiles differed between the summer and fall biomass peaks and shared only 30% common operational taxonomic units (OTUs), suggesting the influence of seasonal factors on these communities. During the second biomass accrual phase, bacterial richness and the appearance of new OTUs fitted a conceptual model of bacterial biofilm succession. During succession, five OTUs (corresponding to Dechloromonas sp., Nitrospira sp., and three different Spirosoma spp.) exhibited particular patterns and were present only during clearly defined successional stages, suggesting differences in life-history strategies for epilithic bacteria. Co-inertia analysis of DGGE banding patterns and physical-chemical data showed a significant relationship between community structure and environmental conditions suggesting that bacterial communities were mainly influenced by seasonal changes (temperature, light) and hydrodynamic stability. Within the periods of stability, analysis of environmental variables and community patterns showed the dominant influence of time and maturation on bacterial community structure. Thus, succession in these naturally occurring epilithic biofilm assemblages appears to occur through a combination of allogenic (seasonal) and autogenic changes.

Cross-Ocean Distribution of Rhodobacterales Bacteria as Primary Surface Colonizers in Temperate Coastal Marine Waters

“…The Bacteroidetes are often abundant in riverine and estuarine biofilms and particles (25,31,41). However, the success of Bacteroidetes in particle assemblages may be due more to their VOL.…”

“…Microbial surface colonization may proceed via ordered steps (15,25,31,46,52,59), starting with initial sensing and interaction of the primary colonizers with surfaces (30,42,51). Prokaryotes are usually the major pioneer colonizers (34).…”

Fungal diversity of marine biofilms on artificial reefs in the north-central Gulf of Mexico

“…Biofilm collection techniques were based on the methods of Lyautey et al (2005). Upon returning to the laboratory, the rocks were placed in labelled sterile plastic containers according to sample site with 100 ml sterile distilled water.…”

Organic matter availability structures of microbial biomass and their activity in Pachamalai Forested stream in Tamilnadu.

“…Lignocelluloses the major components of biomass are degraded by that enzyme itself. Natural disturbance, from seasonal changes rainfall and tree fall, to hurricane damage, cause population shifts and changes to communities of bacteria (Lyautey, et al, 2005). To understand the ecology of these microorganisms, their interactions, and the functions they perform, it is important to study them in their natural habitats (Sterflinger, et al, 1998).…”