Effect of Galactose on EPS Production and Attachment of Acidithiobacillus thiooxidans to Mineral Surfaces

2017 ◽  
Vol 262 ◽  
pp. 476-481
Author(s):  
Paulina Aguirre ◽  
Aminael Sánchez Rodríguez ◽  
Juan Carlos Gentina ◽  
Axel Schippers
Keyword(s):  
Biofilm Formation ◽  
Microbial Growth ◽  
Extracellular Polymeric Substances ◽  
Elemental Sulfur ◽  
Culture Media ◽  
Acidithiobacillus Thiooxidans ◽  
Mineral Surfaces ◽  
Planktonic Cells ◽  
Cell Adherence ◽  
A Cell

The presence of extracellular polymeric substances (EPS) and their relevance for biofilm formation on the mineral surface for a variety of microbial species play a fundamental role in the degradation of sulfide ores. EPS production is associated with induction or auto induction mechanisms as a response of bacteria to environmental conditions. In this study, we tested galactose as an inducer of EPS production in planktonic cells of Acidithiobacillus thiooxidans DSM 14887T and their adherence to polymetallic mineral surfaces. Cells of At. thiooxidans were first adapted to grow at different concentrations of galactose (0.15, 0.25, 0.35%) using a modified 9K liquid medium and elemental sulfur as the energy source. In order to determine EPS production, the microorganisms were grown for 24 hours at different concentrations of galactose. Our results showed a cell adherence of 84% cells within 4 hours in presence of 0.15% galactose compared to 70% without galactose. The optimal concentration of galactose for maximal EPS production was 0.25% and for the attachment of cells it was 0.15%. Higher galactose concentrations inhibited microbial growth and decreased the number of cells attached to the mineral. While with a small amount of galactose in the culture media can shift the balance between sessile cells and planktonic cells, generating an increase in adhesion and therefore a possible increase of the bioleaching rate.

Insights into Bacterial Milk Spoilage with Particular Emphasis on the Roles of Heat-Stable Enzymes, Biofilms, and Quorum Sensing

2018 ◽  
Vol 81 (10) ◽  
pp. 1651-1660 ◽  
Author(s):  
LEI YUAN ◽  
FAIZAN A. SADIQ ◽  
METTE BURMØLLE ◽  
TONGJIE LIU ◽  
GUOQING HE
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Enzyme Production ◽  
Extracellular Polymeric Substances ◽  
Hydrolytic Enzymes ◽  
Heat Stability ◽  
Planktonic Cells ◽  
Psychrotrophic Bacteria ◽  
Effective Strategies ◽  
Heat Stable

ABSTRACT Milk spoilage caused by psychrotrophic bacteria and their heat-stable enzymes is a serious challenge for the dairy industry. In many studies, spoilage has been explored based on the simplistic view of undesirable enzymes produced by planktonic cells. Recently, biofilms and quorum sensing (QS) have been suggested as important factors in the deterioration of milk, which opens new avenues for investigation of the processes and challenges. Production and heat stability of enzymes are enhanced in biofilms, mainly because of inherent differences in physiological states and protective shielding by extracellular polymeric substances. QS plays a key role in modulating expression of hydrolytic enzymes and biofilm formation. To date, few studies have been conducted to investigate the complex interplays of enzyme production, biofilm formation, and QS. This review provides novel insights into milk spoilage with particular emphasis on the roles of biofilms and QS and summarizes potential effective strategies for controlling the spoilage of milk.

Is the Quorum Sensing Type AI-1 System of Acidithiobacillus ferrooxidans Involved in its Attachment to Mineral Surfaces?

2007 ◽  
Vol 20-21 ◽  
pp. 345-349
Author(s):  
Lina María Ruíz ◽  
Alex Gonzalez ◽  
Marine Frezza ◽  
Laurent Soulère ◽  
Yves Queneau ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Acidithiobacillus Ferrooxidans ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Acyl Chain ◽  
Bacterial Attachment ◽  
Mineral Surfaces ◽  
Gene Encoding ◽  
Biofilm Development ◽  
Chain Lengths

Biofilm development plays a pivotal role in the bioleaching process. The attachment of the acidophilic chemolithotrophic Acidithiobacillus ferrooxidans to mineral surfaces is mediated by extracellular polymeric substances (EPS) involved in biofilm development. Previous work suggests that EPS composition of A. ferrooxidans is adapted to the energy source and, accordingly, the bacterium must be able to sense the surface to which attachment occurs with the consequent triggering of the expression of different EPS-genes. Quorum sensing (QS) is recognized as one of the main regulators of biofilm formation. A. ferrooxidans possesses a functional QS type AI-1 system and the analysis of culture supernatants revealed us that this bacterium is able to synthesize nine different homoserine lactones (AHLs) whose acyl-chain lengths oscillate between 8 and 16 carbons and include an alcohol or a ketone function at the C3 position. The transcription levels of the afeI gene encoding for the AHL synthase are higher in cells grown in sulfur and thiosulfate media than in iron-grown cells, suggesting that biofilm formation in A. ferrooxidans would be regulated by the QS type AI-1 system. In the present study, the effect of several synthetic AHLs and analogues on the attachment of A. ferrooxidans to pyrite was analyzed. Preliminary results suggest that some of these molecules are changing the bacterial attachment to pyrite.

scholarly journals The Helicobacter pylori biofilm involves a multi-gene stress-biased response including a structural role for flagella

2018 ◽  
Author(s):  
Skander Hathroubi ◽  
Julia Zerebinski ◽  
Karen M. Ottemann
Keyword(s):  
Helicobacter Pylori ◽  
Stress Response ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Cell Envelope ◽  
Flagellar Apparatus ◽  
Growth Conditions ◽  
Planktonic Cells ◽  
H Pylori ◽  
Biofilm Matrix

AbstractHelicobacter pylori has an impressive ability to persist chronically in the human stomach. Similar characteristics are associated with biofilm formation in other bacteria. The H. pylori biofilm process, however, is poorly understood. To gain insight into this mode of growth, we carried out comparative transcriptomic analysis between H. pylori biofilm and planktonic cells, using the mouse colonizing strain SS1. Optimal biofilm formation was obtained with low serum and three-day growth, conditions which caused both biofilm and planktonic cells to be ∼80% coccoid. RNA-seq analysis found that 8.18% of genes were differentially expressed between biofilm and planktonic cell transcriptomes. Biofilm-downregulated genes included those involved in metabolism and translation, suggesting these cells have low metabolic activity. Biofilm-upregulated genes included those whose products were predicted to be at the cell envelope, involved in regulating a stress response, and surprisingly, genes related to formation of the flagellar apparatus. Scanning electron microscopy visualized flagella that appeared to be a component of the biofilm matrix, supported by the observation that an aflagellated mutant displayed a less robust biofilm with no apparent filaments. We observed flagella in the biofilm matrix of additional H. pylori strains, supporting that flagellar use is widespread. Our data thus supports a model in which H. pylori biofilm involves a multi-gene stress-biased response, and that flagella play an important role in H. pylori biofilm formation.IMPORTANCEBiofilms, communities of bacteria that are embedded in a hydrated matrix of extracellular polymeric substances, pose a substantial health risk and are key contributors to many chronic and recurrent infections. Chronicity and recalcitrant infections are also common features associated with the ulcer-causing human pathogen H. pylori. However, relatively little is known about the role of biofilms in H. pylori pathogenesis as well as the biofilm structure itself and the genes associated with this mode of growth. In the present study, we found that H. pylori biofilm cells highly expressed genes related to cell envelope, stress response and those encoding the flagellar apparatus. Flagellar filaments were seen in high abundance in the biofilm. Flagella are known to play a role in initial biofilm formation, but typically are downregulated after that state. H. pylori instead appears to have co-opted these structures for non-motility roles, including a role building a robust biofilm.

Attachment Behavior of Leaching Bacteria to Metal Sulfides Elucidated by Combined Atomic Force and Epifluorescence Microscopy

2009 ◽  
Vol 71-73 ◽  
pp. 337-340 ◽  
Author(s):  
Bianca M. Florian ◽  
Nanni Noël ◽  
Soeren Bellenberg ◽  
J. Huergo ◽  
Thore Rohwerder ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Spatial Arrangement ◽  
Epifluorescence Microscopy ◽  
Metal Sulfides ◽  
Mineral Surface ◽  
Planktonic Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
Leaching Bacteria

The aim of the study was to quantify and to visualize colonization of metal sulfides by pure and mixed cultures. Strains of the genera Acidithiobacillus and Leptospirillum were tested. Sessile and planktonic cells were visualized by fluorescence microscopy using 4',6-diamidino-2-phenylindole (DAPI) and FISH. Additionally, atomic force microscopy was used for the investigations on cell morphology, spatial arrangement of cells on metal sulfides and mineral surface topography. It was shown that the morphology of sessile cells was totally different as compared with planktonic ones. Interactions of different species resulted in increased production of extracellular polymeric substances (EPS) or caused negligible-attaching bacteria to be incorporated into a biofilm by the good attaching ones. Consequently, biofilm formation was furthered.

EPS Characterization of a Cell Wall-Lacking Archaeon Ferroplasma acidiphilum

2017 ◽  
Vol 262 ◽  
pp. 434-438
Author(s):  
Rui Yong Zhang ◽  
Veronique Blanchard ◽  
Mario Vera Véliz ◽  
Wolfgang Sand
Keyword(s):  
Cell Wall ◽  
Surface Characterization ◽  
Extracellular Polymeric Substances ◽  
Lectin Binding ◽  
Attenuated Total Reflection ◽  
Metal Sulfides ◽  
Mineral Surfaces ◽  
A Cell ◽  
Insight Into

We studied the surface properties of F. acidiphilum DSM 28986 by attenuated total reflection-Fourier transformed infra-red (ATR-FTIR) spectroscopy and microbial adhesion to hydrocarbon (MATH) techniques. In addition, extracellular polymeric substances (EPS) were extracted and characterized by conventional colorimetric analysis and fluorescence lectin-binding analysis (FLBA). Results showed that: 1) cells selectively adhered to mineral surfaces and showed maximum attachment to pyrite of approx. 50% within 30 min; 2) EPS synthesis by F. acidiphilum DSM 28986 was influenced by growth substrates; and 3) tightly-bound EPS (capsular EPS) were composed of carbohydrates and proteins. In contrast, loosely-bound EPS (colloidal EPS) were mainly characterized as carbohydrates. Monosaccharides like glucose, fucose, arabinose, galactose, mannose, and sialic acid were detected in the EPS of F. acidiphilum DSM 28986. This study provides first insight into surface characterization of the cell wall-lacking archaeon F. acidiphilum and facilitates the understanding of interactions of this organism with other acidophiles and metal sulfides.

Initial Attachment and Biofilm Formation of a Novel Crenarchaeote on Mineral Sulfides

2015 ◽  
Vol 1130 ◽  
pp. 127-130 ◽  
Author(s):  
Rui Yong Zhang ◽  
Yu Tong Zhang ◽  
Thomas R. Neu ◽  
Qian Li ◽  
Sören Bellenberg ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Extracellular Polymeric Substances ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Mineral Surfaces ◽  
Initial Attachment ◽  
Fluorescent Stains ◽  
Mineral Sulfides

This study focused on colonization and biofilm formation of a new crenarchaeoteAcidianussp. DSM 29099 on pyrite and chalcopyrite. Confocal laser scanning microscopy (CLSM) in combination with several fluorescent stains was applied to examine spatial distribution of cells and biofilms, as well as extracellular polymeric substances (EPS) production on the substrates. Around 60% and 35% of the inoculum adhered to pyrite and chalcopyrite within 2 h, respectively. Cells ofAcidianussp. DSM 29099 were heterogeneously distributed on both pyrite and chalcopyrite surfaces, while large mineral surfaces remained uncolonized. Biofilm cells on pyrite were often found to be embeded in EPS. EPS residues like mannose and glucose were possibly involved in intial attachment to pyrite. A mature biofilm on pyrite was developed after 2-4 days of incubation.

scholarly journals Influence of Culture Media on Biofilm Formation byCandidaSpecies and Response of Sessile Cells to Antifungals and Oxidative Stress

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Isela Serrano-Fujarte ◽  
Everardo López-Romero ◽  
Georgina Elena Reyna-López ◽  
Ma. Alejandrina Martínez-Gámez ◽  
Arturo Vega-González ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Culture Media ◽  
Planktonic Cells ◽  
Human Immune System ◽  
Xtt Assay ◽  
Nutritional Conditions ◽  
Complex Process ◽  
Sessile Cells

The aims of the study were to evaluate the influence of culture media on biofilm formation byC. albicans, C. glabrata, C. krusei,andC. parapsilosisand to investigate the responses of sessile cells to antifungals and reactive oxygen species (ROS) as compared to planktonic cells. For biofilm formation, theCandidaspecies were grown at different periods of time in YP or YNB media supplemented or not with 0.2 or 2% glucose. Sessile and planktonic cells were exposed to increasing concentrations of antifungals, H2O2, menadione or silver nanoparticles (AgNPs). Biofilms were observed by scanning electron microscopy (SEM) and quantified by the XTT assay.C. albicansformed biofilms preferentially in YPD containing 2% glucose (YPD/2%),C. glabratain glucose-free YNB or supplemented with 0.2% glucose (YNB/0.2%), whileC. kruseiandC. parapsilosispreferred YP, YPD/0.2%, and YPD/2%. Interestingly, onlyC. albicansproduced an exopolymeric matrix. This is the first report dealing with thein vitroeffect of the culture medium and glucose on the formation of biofilms in fourCandidaspecies as well as the resistance of sessile cells to antifungals, AgNPs, and ROS. Our results suggest that candidiasisin vivois a multifactorial and complex process where the nutritional conditions, the human immune system, and the adaptability of the pathogen should be considered altogether to provide an effective treatment of the patient.

scholarly journals Mathematical Modelling of the Effects of Plasma Treatment on the Diffusivity of Biofilm

2018 ◽  
Vol 8 (10) ◽  
pp. 1729 ◽  
Author(s):  
Tripti Gupta ◽  
Surya Karki ◽  
Ronald Fournier ◽  
Halim Ayan
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Treatment Approach ◽  
Clinical Settings ◽  
Physical Barrier ◽  
Planktonic Cells ◽  
The Matrix ◽  
Implanted Medical Devices ◽  
Non Thermal Plasma ◽  
Combinatorial Treatment

Biofilm formation on implanted medical devices is the reason for most of the nosocomial infections in clinical settings. Biofilms are more resistant to antimicrobials than their planktonic cells mainly because of the presence of the matrix of extracellular polymeric substances (EPSs), which acts as a physical barrier that limits the transport of antimicrobials inside the biofilm. A combinatorial antimicrobial approach of a non-thermal plasma and chlorhexidine (CHX) digluconate can be used to sterilize those surfaces contaminated with biofilm. However, the reason behind achieving this combinatorial decontamination is not known. Thus, in this study, we developed a mathematical model to explain the reason behind sterilization with the combinatorial treatment approach. It was found that the application of plasma prior to treatment with CHX is disrupting the biofilm and making it very porous. This is allowing CHX to penetrate deeper inside the porous biofilm, which is then effective at sterilizing the biofilm.

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