High copper concentration reduces biofilm formation in Acidithiobacillus ferrooxidans by decreasing production of extracellular polymeric substances and its adherence to elemental sulfur

Extracellular polymeric substances (EPS) of Acidithiobacillus ferrooxidans and other leaching microorganisms mediate the attachment of cells to pyrite and other minerals. They also play a pivotal role in indirect leaching of base and precious metals via the contact mechanism. The aim of this study is to get more insight on the influence of the growth substrates iron(II) ions, pyrite, chalcopyrite and elemental sulfur on EPS formation, attachment and biofilm formation. The synthesis of EPS by cells of A. ferrooxidans strain A2 is strongely influenced by the growth substrate or attachment substratum of the cells. Cells grown with soluble iron(II) ions generally generate less EPS than cells grown with solid pyrite, chalcopyrite or elemental sulfur. Planktonic cells grown in the presence of solid substrate produce two to four times more EPS than iron(II) ion grown cells. With sessile cells, this factor is further increased to 50 to 240 depending on the specific substrate. The EPS of all the differently grown planktonic and sessile cells of A. ferrooxidans strain A2 contained neutral sugars, fatty acids, uronic acids, proteins and metal ions. The composition of these compounds varied with the growth substrate and type (planktonic or sessile). The attachment behavior of cells of A. ferrooxidans strain A2 also differed with the substrate of the pre-culture. Cells grown on iron(II) ions, pyrite or chalcopyrite attached rapidly to pyrite and chalcopyrite, while attachment to elemental sulfur was poor. On the contrary, sulfur grown cells attached well to elemental sulfur but weakly to pyrite and chalcopyrite. Attachment of EPS-free cells to all substrates was also diminished. Cells of A. ferrooxidans strain A2 cover mineral surfaces with a dense biofilm after a few days of cultivation, as visualized by fluorescence microscopy and AFM. Large amounts of EPS are formed, which eventually cover the cells and the mineral surface. Even after a few weeks of cultivation the biofilm remained monolayered on all substrates.

Download Full-text

Identification and characterization of Acidithiobacillus ferrooxidans YY2 and its application in the biodesulfurization of coal

Canadian Journal of Microbiology ◽

10.1139/cjm-2014-0250 ◽

2015 ◽

Vol 61 (1) ◽

pp. 65-71 ◽

Cited By ~ 4

Author(s):

Xinping Yang ◽

Shimei Wang ◽

Yujiao Liu ◽

Yuanyuan Zhang

Keyword(s):

Acidithiobacillus Ferrooxidans ◽

Extracellular Polymeric Substances ◽

Sequencing Batch Reactor ◽

Elemental Sulfur ◽

Batch Reactor ◽

Sulfur Removal ◽

Oxidation Activity ◽

Oxidation Efficiency ◽

Identification And Characterization

The acidophilic Fe-oxidizing and S-oxidizing bacterium YY2 was isolated from the acid drainage of a coalmine. Based on morphological and physiological characteristics and phylogenetic analysis, it was identified as Acidithiobacillus ferrooxidans. Significant differences were observed in the oxidation efficiency and cell morphology when YY2 was cultured in 9K medium with ferrous ion (Fe2+), elemental sulfur (S0), and pyrite as the sole energy source. YY2 exhibited marked Fe2+ oxidation activity; 44.2 g·L−1 FeSO4·7H2O was completely oxidized in 30 h, but the rates of S0 and pyrite oxidization were slower. After 20 days, the efficiencies of oxidizing 10 g·L−1 S0 and 10 g·L−1 pyrite were approximately 9.6% and 20%, respectively. Cells cultured in pyrite as substrate secreted more extracellular polymeric substances than they did when cultured in Fe2+ or S0. Additionally, 75% total sulfur removal and 86% pyritic sulfur removal was achieved in a sequencing batch reactor of biodesulfurization of coal.

Download Full-text

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.20-21.345 ◽

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.

Download Full-text

Influence of Different Growth Conditions on the Composition of Extracellular Polymeric Substances of Acidithiobacillus ferrooxidans and Acidithiobacillus ferrivorans Species

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1130.11 ◽

2015 ◽

Vol 1130 ◽

pp. 11-14

Author(s):

Natascha Caroline Teubner ◽

Sören Bellenberg ◽

Mario Vera ◽

Wolfgang Sand

Keyword(s):

Acidithiobacillus Ferrooxidans ◽

Extracellular Polymeric Substances ◽

Elemental Sulfur ◽

Mine Drainage ◽

Cation Exchange Resin ◽

Metal Sulfide ◽

Growth Conditions ◽

Extracellular Dna ◽

Low Grade ◽

Cultivation Conditions

Acidithiobacillus ferrooxidansandAcidithiobacillus ferrivoransare used in bioleaching to recover metals such as copper or gold from low-grade ores.At. ferrooxidansis one of the best studied bioleaching microorganisms.At. ferrivoransis known for its ability to leach ores at low temperature. Both microorganisms are involved in acid mine drainage (AMD) formation. The cells are embedded in extracellular polymeric substances (EPS), which play an important role in the attachment to metal-sulfide-surfaces and in catalysis of their dissolution. EPS amounts and compositions differ, depending on the energy source, as it was shown forAt. ferrooxidansR1. Recently,At. ferrooxidansstrains were reclassified into four different subgroups, which are considered to correspond to four different species. As well, a biofilm study, using three of these closely related iron-oxidizingAcidithiobacillusspecies, demonstrated differences regarding attachment to pyrite among them. Consequently, this study focuses on the investigation ofAt. ferrooxidansandAt. ferrivoransspecies and their EPS composition with regard to varying cultivation conditions. Also different energy sources like, elemental sulfur or pyrite were tested. EPS were extracted by the use of a cation exchange resin (DOWEX). Obtained EPS were analyzed for their total amount of proteins, extracellular DNA (eDNA) and carbohydrates.

Download Full-text

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

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.262.476 ◽

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.

Download Full-text

Process Description of an Unconventional Biofilm Formation by Bacterial Cells Autoagglutinating Through Sticky, Long, and Peritrichate Nanofibers

10.26434/chemrxiv.10001924.v1 ◽

2019 ◽

Author(s):

Yoshihide Furuichi ◽

Shogo Yoshimoto ◽

Tomohiro Inaba ◽

Nobuhiko Nomura ◽

Katsutoshi Hori

Keyword(s):

Formation Process ◽

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Waste Treatment ◽

Large Cell ◽

Dlvo Theory ◽

Bacterial Cells ◽

Chemical Production ◽

Discontinuous Surface ◽

Cell Cell

Biofilms are used in environmental biotechnologies including waste treatment and environmentally friendly chemical production. Understanding the mechanisms of biofilm formation is essential to control microbial behavior and improve environmental biotechnologies. Acinetobacter sp. Tol 5 autoagglutinate through the interaction of the long, peritrichate nanofiber protein AtaA, a trimeric autotransporter adhesin. Using AtaA, without cell growth or the production of extracellular polymeric substances, Tol 5 cells quickly form an unconventional biofilm. In this study, we investigated the formation process of this unconventional biofilm, which started with cell–cell interactions, proceeded to cell clumping, and led to the formation of large cell aggregates. The cell–cell interaction was described by DLVO theory based on a new concept, which considers two independent interactions between two cell bodies and between two AtaA fiber tips forming a virtual discontinuous surface. If cell bodies cannot collide owing to an energy barrier at low ionic strengths but approach within the interactive distance of AtaA fibers, cells can agglutinate through their contact. Cell clumping proceeds following the cluster–cluster aggregation model, and an unconventional biofilm containing void spaces and a fractal nature develops. Understanding its formation process would extend the utilization of various types of biofilms, enhancing environmental biotechnologies.

Download Full-text

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

Current Pharmaceutical Biotechnology ◽

10.2174/1389201020666191112155905 ◽

2020 ◽

Vol 21 (4) ◽

pp. 270-286 ◽

Cited By ~ 2

Author(s):

Fazlurrahman Khan ◽

Dung T.N. Pham ◽

Sandra F. Oloketuyi ◽

Young-Mog Kim

Keyword(s):

Biofilm Formation ◽

Pathogenic Bacteria ◽

Extracellular Polymeric Substances ◽

Quorum Quenching ◽

Resistance Mechanisms ◽

Bacterial Biofilm ◽

Bacterial Cells ◽

High Concentration ◽

Biofilm Inhibition ◽

Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

Download Full-text

Correction to: Floating particles with high copper concentration in the sea-surface microlayer

Environmental Science and Pollution Research ◽

10.1007/s11356-021-14518-w ◽

2021 ◽

Author(s):

Hideo Okamura ◽

Kenta Kano ◽

Chee Kong Yap ◽

Christina Emmanouil

Keyword(s):

Copper Concentration ◽

Sea Surface ◽

Surface Microlayer ◽

High Copper ◽

Sea Surface Microlayer ◽

Floating Particles

Download Full-text

Biofilm Formation in Xanthomonas arboricola pv. pruni: Structure and Development

Agronomy ◽

10.3390/agronomy11030546 ◽

2021 ◽

Vol 11 (3) ◽

pp. 546

Author(s):

Pilar Sabuquillo ◽

Jaime Cubero

Keyword(s):

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Environmental Changes ◽

Nutrient Content ◽

Infection Process ◽

Bacterial Attachment ◽

Key Factors ◽

Cell Structures ◽

Microscopy Techniques

Xanthomonasarboricola pv. pruni (Xap) causes bacterial spot of stone fruit and almond, an important plant disease with a high economic impact. Biofilm formation is one of the mechanisms that microbial communities use to adapt to environmental changes and to survive and colonize plants. Herein, biofilm formation by Xap was analyzed on abiotic and biotic surfaces using different microscopy techniques which allowed characterization of the different biofilm stages compared to the planktonic condition. All Xap strains assayed were able to form real biofilms creating organized structures comprised by viable cells. Xap in biofilms differentiated from free-living bacteria forming complex matrix-encased multicellular structures which become surrounded by a network of extracellular polymeric substances (EPS). Moreover, nutrient content of the environment and bacterial growth have been shown as key factors for biofilm formation and its development. Besides, this is the first work where different cell structures involved in bacterial attachment and aggregation have been identified during Xap biofilm progression. Our findings provide insights regarding different aspects of the biofilm formation of Xap which improve our understanding of the bacterial infection process occurred in Prunus spp and that may help in future disease control approaches.

Download Full-text

Transcriptome Analysis Reveals the Genes Involved in Bifidobacterium Longum FGSZY16M3 Biofilm Formation

Microorganisms ◽

10.3390/microorganisms9020385 ◽

2021 ◽

Vol 9 (2) ◽

pp. 385 ◽

Cited By ~ 1

Author(s):

Zongmin Liu ◽

Lingzhi Li ◽

Qianwen Wang ◽

Faizan Ahmed Sadiq ◽

Yuankun Lee ◽

...

Keyword(s):

Network Analysis ◽

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Molecular Mechanisms ◽

Early Stage ◽

Bifidobacterium Longum ◽

Regulation Of Gene Expression ◽

Interaction Network ◽

Structural Development ◽

Sequencing Analysis

Biofilm formation has evolved as an adaptive strategy for bacteria to cope with harsh environmental conditions. Currently, little is known about the molecular mechanisms of biofilm formation in bifidobacteria. A time series transcriptome sequencing analysis of both biofilm and planktonic cells of Bifidobacterium longum FGSZY16M3 was performed to identify candidate genes involved in biofilm formation. Protein–protein interaction network analysis of 1296 differentially expressed genes during biofilm formation yielded 15 clusters of highly interconnected nodes, indicating that genes related to the SOS response (dnaK, groS, guaB, ruvA, recA, radA, recN, recF, pstA, and sufD) associated with the early stage of biofilm formation. Genes involved in extracellular polymeric substances were upregulated (epsH, epsK, efp, frr, pheT, rfbA, rfbJ, rfbP, rpmF, secY and yidC) in the stage of biofilm maturation. To further investigate the genes related to biofilm formation, weighted gene co-expression network analysis (WGCNA) was performed with 2032 transcript genes, leading to the identification of nine WGCNA modules and 133 genes associated with response to stress, regulation of gene expression, quorum sensing, and two-component system. These results indicate that biofilm formation in B. longum is a multifactorial process, involving stress response, structural development, and regulatory processes.

Download Full-text