Comparing the microbial characteristics of rainwater in two operating rainwater tanks with different surface-to-volume ratios

2011 ◽  
Vol 64 (3) ◽  
pp. 627-631 ◽  
Author(s):  
Mikyeong Kim ◽  
Gippeum Bak ◽  
Mooyoung Han

In this study, the microbial characteristics of rainwater in two tanks with different surface-to-volume ratios were investigated and compared to determine how the internal design features of storage tanks affect water quality. The particle and nutrient parameters of the rainwater, including turbidity, suspended solids, total organic carbon, and total phosphate, were lower in Tank 2, which had a surface-to-volume ratio 7.5 times greater than that of Tank 1. In addition, although the rainwater was collected from the same catchment area, the water in Tank 1 had greater numbers of bacteria, and the bacterial communities in the water differed between the two storage tanks. It appears that the differences in the inside surface structures of the rainwater tanks affected the microbial ecosystems. Increasing the surface-to-volume ratio in rainwater tanks may affect rainwater quality, because this extends the area for biofilm development. Further study of the role of biofilm in rainwater tank is required precisely, and its function needs to be considered in the design and management of rainwater tanks.

2020 ◽  
Author(s):  
Kimberly D. Myers ◽  
◽  
Katrina Lee Jewell ◽  
P.S.K. Knappett ◽  
Mehtaz M. Lipsi ◽  
...  

2020 ◽  
pp. 124996
Author(s):  
Diwu Fan ◽  
Shengyan Wang ◽  
Yanhui Guo ◽  
Jian Liu ◽  
Evgenios Agathokleous ◽  
...  

2019 ◽  
Vol 98 (7) ◽  
pp. 739-745 ◽  
Author(s):  
C. Cugini ◽  
M. Shanmugam ◽  
N. Landge ◽  
N. Ramasubbu

The oral cavity contains a rich consortium of exopolysaccharide-producing microbes. These extracellular polysaccharides comprise a major component of the oral biofilm. Together with extracellular proteins, DNA, and lipids, they form the biofilm matrix, which contributes to bacterial colonization, biofilm formation and maintenance, and pathogenesis. While a number of oral microbes have been studied in detail with regard to biofilm formation and pathogenesis, the exopolysaccharides have been well characterized for only select organisms, namely Streptococcus mutans and Aggregatibacter actinomycetemcomitans. Studies on the exopolysaccharides of other oral organisms, however, are in their infancy. In this review, we present the current research on exopolysaccharides of oral microbes regarding their biosynthesis, regulation, contributions to biofilm formation and stability of the matrix, and immune evasion. In addition, insight into the role of exopolysaccharides in biofilms is highlighted through the evaluation of emerging techniques such as pH probing of biofilm colonies, solid-state nuclear magnetic resonance for macromolecular interactions within biofilms, and super-resolution microscopy analysis of biofilm development. Finally, exopolysaccharide as a potential nutrient source for species within a biofilm is discussed.


1982 ◽  
Vol 16 (5) ◽  
pp. 649-654 ◽  
Author(s):  
J.E. Rae ◽  
S.R. Aston
Keyword(s):  

2005 ◽  
Vol 6 (1) ◽  
pp. 105-118 ◽  
Author(s):  
G. M. Nava ◽  
L. R. Bielke ◽  
T. R. Callaway ◽  
M. P Castañeda

AbstractThe intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of beneficial bacterial communities and metabolites from these complex ecosystems has varying consequences for host health. This hypothesis has led to the introduction of novel therapeutic interventions based on the consumption of beneficial bacterial cultures. Mechanisms by which probiotic bacteria affect the microecology of the gastrointestinal tract are not well understood, but at least three mechanisms of action have been proposed: production/presence of antibacterial substances (e.g., bacteriocins or colicins), modulation of immune responses and specific competition for adhesion receptors to intestinal epithelium. The rapid establishment of bacterial communities has been thought to be essential for the prevention of colonization by pathogenic bacteria. Some animal models suggest that the reduction in bacterial translocation in neonatal animals could be associated with an increase in intestinal bacterial communities and bacteriocin-like inhibitory substances produced by these species. This review emphasizes the role of the intestinal microbiota in the reduction of the gastrointestinal infections and draws heavily on studies in poultry.


2008 ◽  
Vol 72 (1) ◽  
pp. 85-89 ◽  
Author(s):  
J. R. Leake ◽  
A. L. Duran ◽  
K. E. Hardy ◽  
I. Johnson ◽  
D. J. Beerling ◽  
...  

AbstractBiological weathering is a function of biotic energy expenditure. Growth and metabolism of organisms generates acids and chelators, selectively absorbs nutrient ions, and applies turgor pressure and other physical forces which, in concert, chemically and physically alter minerals. In unsaturated soil environments, plant roots normally form symbiotic mycorrhizal associations with fungi. The plants provide photosynthate-carbohydrate-energy to the fungi in return for nutrients absorbed from the soil and released from minerals. In ectomycorrhiza, one of the two major types of mycorrhiza of trees, roots are sheathed in fungus, and 15—30% of the net photosynthate of the plants passes through these fungi into the soil and virtually all of the water and nutrients taken up by the plants are supplied through the fungi. Here we show that ectomycorrhizal fungi actively forage for minerals and act as biosensors that discriminate between different grain sizes (53—90 μm, 500—1000 μm) and different minerals (apatite, biotite, quartz) to favour grains with a high surface-area to volume ratio and minerals with the highest P content. Growth and carbon allocation of the fungi is preferentially directed to intensively interact with these selected minerals to maximize resource foraging.


2005 ◽  
Vol 52 (1-2) ◽  
pp. 73-78 ◽  
Author(s):  
T. Zhang ◽  
S. Z. Ke ◽  
Y. Liu ◽  
H.P. Fang

Microbial properties of a methanogenic granular phenol-degrading sludge were characterized using the 16S rRNA/DNA-based techniques, including polymerase chain reaction (PCR) amplification, cloning, DNA sequencing, and fluorescence in situ hybridization (FISH). The sludge was sampled from an upflow anaerobic sludge blanket reactor, which removed 98% of phenol (up to 1260 mg/l) in wastewater at 26°C with 12 hours of hydraulic retention. Based on DNA analysis, the Eubacteria in the sludge was composed of 13 operational taxonomy units (OTUs). Two OTUs, one resembling Clostridium and the other remotely resembling Desulfotomaculum, were likely responsible for the conversion of phenol to benzoate, which was further degraded by five Syntrophus-resembling OTUs to acetate and H2/CO2; methanogens lastly converted acetate and H2/CO2 into methane. The role of six remaining OTUs remains unclear. Overall, the sludge was composed of 26±6% Eubacteria and 74±9% methanogens, of which 54±6% were acetotrophic Methanosaetaceae, 14±3% and 3±2% were hydrogenotrophic Methanomicrobiales and Methanobacteriaceae, respectively.


mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Connor J. Beebout ◽  
Allison R. Eberly ◽  
Sabrina H. Werby ◽  
Seth A. Reasoner ◽  
John R. Brannon ◽  
...  

ABSTRACT Biofilms are multicellular bacterial communities encased in a self-secreted extracellular matrix comprised of polysaccharides, proteinaceous fibers, and DNA. Organization of these components lends spatial organization to the biofilm community such that biofilm residents can benefit from the production of common goods while being protected from exogenous insults. Spatial organization is driven by the presence of chemical gradients, such as oxygen. Here we show that two quinol oxidases found in Escherichia coli and other bacteria organize along the biofilm oxygen gradient and that this spatially coordinated expression controls architectural integrity. Cytochrome bd, a high-affinity quinol oxidase required for aerobic respiration under hypoxic conditions, is the most abundantly expressed respiratory complex in the biofilm community. Depletion of the cytochrome bd-expressing subpopulation compromises biofilm complexity by reducing the abundance of secreted extracellular matrix as well as increasing cellular sensitivity to exogenous stresses. Interrogation of the distribution of quinol oxidases in the planktonic state revealed that ∼15% of the population expresses cytochrome bd at atmospheric oxygen concentration, and this population dominates during acute urinary tract infection. These data point toward a bet-hedging mechanism in which heterogeneous expression of respiratory complexes ensures respiratory plasticity of E. coli across diverse host niches. IMPORTANCE Biofilms are multicellular bacterial communities encased in a self-secreted extracellular matrix comprised of polysaccharides, proteinaceous fibers, and DNA. Organization of these components lends spatial organization in the biofilm community. Here we demonstrate that oxygen gradients in uropathogenic Escherichia coli (UPEC) biofilms lead to spatially distinct expression programs for quinol oxidases—components of the terminal electron transport chain. Our studies reveal that the cytochrome bd-expressing subpopulation is critical for biofilm development and matrix production. In addition, we show that quinol oxidases are heterogeneously expressed in planktonic populations and that this respiratory heterogeneity provides a fitness advantage during infection. These studies define the contributions of quinol oxidases to biofilm physiology and suggest the presence of respiratory bet-hedging behavior in UPEC.


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