Comment on: Densely adherent growth mode, rather than extracellular polymer substance matrix build-up ability, contributes to high resistance of Staphylococcus epidermidis biofilms to antibiotics

A total of 37 Staphylococcus epidermidis isolates, isolated from corneal scraping of patients with bacterial keratitis and 20 isolates from healthy eyes (as control) (all isolates, isolated from, Ibn Al- Haietham eye hospital / Baghdad), were tested for slime production, 52.63% of all isolates were positive-slime production (23 isolates from patients and 7 isolates from controls). It was found that positive-slime producing S. epidermidis were exhibited a high resistance to antibiotics as compared to negative-slime producing isolates.

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A novel bioflocculant for chromium (Ⅵ) and arsenic (Ⅲ) removal: Extracellular polymeric substance (EPS) of Pseudomonas fluorescens

10.5194/egusphere-egu2020-7964 ◽

2020 ◽

Author(s):

Ning He

Keyword(s):

Pseudomonas Fluorescens ◽

Batch Fermentation ◽

Soil Bacteria ◽

Metal Removal ◽

Heavy Metal Removal ◽

Environmental Friendliness ◽

Extracellular Polymer Substance ◽

Flocculating Activity ◽

Fermentation Strategy ◽

Extracellular Polymer

<p>Bioflocculants produced by microorganisms have advantages in removing heavy metals because of their environmental friendliness and biodegradability. In this study, the bioflocculant from a soil bacteria was investigated for its application in chromium&#160;(&#8549;)&#160;and&#160;arsenic&#160;(&#8546;) removal. The bioflocculant-producing strain was indentified as Pseudomonas fluorescens. It showed maximum flocculating activity of 2579.94 U/mL and yield of 4.84 g/L under optimal condition. With a fed&#8209;batch fermentation strategy, bioflocculant production was further enhanced by 32.6%. The bioflocculant was as extracellular polymer substance composed of 76.67% polysaccharides and 15.8% protein with a molecular weight of 117 kDa. It showed excellent capacities in heavy metal removal, 80.13 and 45.93 mg/g for chromium(&#8549;) and arsenic (&#8546;), respectively. The bioflocculant outperformed conventional adsorption materials and could represent a promising biotechnology for the remediation of environmental problems.</p>

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High-resistance GaN epilayers with low dislocation density via growth mode modification

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2016.06.038 ◽

2016 ◽

Vol 450 ◽

pp. 160-163 ◽

Cited By ~ 6

Author(s):

Z.Y. Xu ◽

F.J. Xu ◽

J.M. Wang ◽

L. Lu ◽

Z.J. Yang ◽

...

Keyword(s):

Dislocation Density ◽

High Resistance ◽

Growth Mode ◽

Low Dislocation Density

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Role of Biofilms in Microbiologically Influenced Corrosion of Metals

Herald of the Bauman Moscow State Technical University Series Natural Sciences ◽

10.18698/1812-3368-2020-1-100-125 ◽

2020 ◽

pp. 100-125

Author(s):

G.Yu. Lomakina

Keyword(s):

Microbial Consortium ◽

Microbiologically Influenced Corrosion ◽

Metal Oxidation ◽

Survival Functions ◽

Anaerobic Conditions ◽

Growth And Survival ◽

Extracellular Polymer Substance ◽

Extracellular Polymer ◽

Aerobic And Anaerobic

Data obtained in the recent years on the effect of bio-films in the development of metal microbiologically influenced corrosion (MIC) are summarized. The main way of sessile cells adaptation and survival on metal surfaces lies in formation of biofilms consisting of living cells surrounded by a multicomponent extracellular polymer substance (EPS). Biosystem created possesses new properties that are different from the properties of individual components. Biofilm ways of formation, growth and survival, functions of the extracellular matrix in regard to the microbial consortium and to the metal surface are presented. Mechanisms of biocorrosion involving the electron transmembrane transition from a metal to the living cell cytoplasm, as well as the extracellular pathways of metal oxidation under aerobic and anaerobic conditions, are considered.

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Extracellular polymer substance synthesized by a halophilic bacterium Chromohalobacter canadensis 28

Applied Microbiology and Biotechnology ◽

10.1007/s00253-018-8901-0 ◽

2018 ◽

Vol 102 (11) ◽

pp. 4937-4949 ◽

Cited By ~ 16

Author(s):

Nadja Radchenkova ◽

Ivanka Boyadzhieva ◽

Nikolina Atanasova ◽

Annarita Poli ◽

Ilaria Finore ◽

...

Keyword(s):

Halophilic Bacterium ◽

Extracellular Polymer Substance ◽

Extracellular Polymer

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Mechanism and kinetics of biofilm growth process influenced by shear stress in sewers

Water Science & Technology ◽

10.2166/wst.2015.633 ◽

2015 ◽

Vol 73 (7) ◽

pp. 1572-1582 ◽

Cited By ~ 9

Author(s):

Hainan Ai ◽

Jingwei Xu ◽

Wei Huang ◽

Qiang He ◽

Bingjie Ni ◽

...

Keyword(s):

Shear Stress ◽

Oxygen Demand ◽

Shear Stresses ◽

Key Factors ◽

Biofilm Growth ◽

Biofilm Thickness ◽

Extracellular Polymer Substance ◽

Hydraulic Conditions ◽

Kinetics Of ◽

Extracellular Polymer

Sewer biofilms play an important role in the biotransformation of substances for methane and sulfide emission in sewer networks. The dynamic flows and the particular shear stress in sewers are the key factors determining the growth of the sewer biofilm. In this work, the development of sewer biofilm with varying shear stress is specifically investigated to gain a comprehensive understanding of the sewer biofilm dynamics. Sewer biofilms were cultivated in laboratory-scale gravity sewers under different hydraulic conditions with the corresponding shell stresses are 1.12 Pa, 1.29 Pa and 1.45 Pa, respectively. The evolution of the biofilm thickness were monitored using microelectrodes, and the variation in total solids (TS) and extracellular polymer substance (EPS) levels in the biofilm were also measured. The results showed that the steady-state biofilm thickness were highly related to the corresponding shear stresses with the biofilm thickness of 2.4 ± 0.1 mm, 2.7 ± 0.1 mm and 2.2 ± 0.1 mm at shear stresses of 1.12 Pa, 1.29 Pa and 1.45 Pa, respectively, which the chemical oxygen demand concentration is 400 mg/L approximately. Based on these observations, a kinetic model for describing the development of sewer biofilms was developed and demonstrated to be capable of reproducing all the experimental data.

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