Anaerobic reduction of hexavalent chromium by bacterial cells of Achromobacter sp. Strain Ch1

Due to the increasing use of antibiotics, measures are being taken to improve their removal from the natural environment. The support of biodegradation with natural surfactants that increase the bioavailability of impurities for microorganisms that degrade them, raises questions about their effect on bacterial cells. In this paper we present analysis of the interaction of nitrofurantoin (NFT) and saponins from the Saponaria officinalis on the environmental bacteria membrane and the model phospholipid membrane mimicking it. A wide perspective of the process is provided with the Langmuir monolayer technique and membrane permeability test with bacteria. The obtained results showed that above critical micelle concentration (CMC), saponin molecules are incorporated into the POPE monolayer, but the NFT impact was ambiguous. What is more, differences in membrane permeability between the cells exposed to NFT in comparison to that of the non-exposed cells were observed above 1.0 CMC for Achromobacter sp. KW1 or above 0.5 CMC for Pseudomonas sp. MChB. In both cases, NFT presence lowered the membrane permeability. Moreover, the Congo red adhesion to the cell membrane also decreased in the presence of a high concentration of surfactants and NFT. The results suggest that saponins are incorporated into the bacteria membrane, but their sugar hydrophilic part remains outside, which modifies the adsorption properties of the cell surface as well as the membrane permeability.

Download Full-text

Electrochemical response to biomass of bacterial cells of Achromobacter sp. CH-1 growth

Transactions of Nonferrous Metals Society of China ◽

10.1016/s1003-6326(17)60109-2 ◽

2017 ◽

Vol 27 (4) ◽

pp. 932-938 ◽

Cited By ~ 1

Author(s):

Yun-yan WANG ◽

Li-yuan CHAI ◽

Qing-wei WANG ◽

Zhi-hui YANG ◽

Rong DENG

Keyword(s):

Bacterial Cells ◽

Electrochemical Response ◽

Achromobacter Sp

Download Full-text

Anaerobic Reduction of Hexavalent Chromium in Filter Sludge of an Electrochemical Process

Environmental Technology ◽

10.1080/09593331808616540 ◽

1997 ◽

Vol 18 (3) ◽

pp. 301-307 ◽

Cited By ~ 3

Author(s):

K. Sulzbacher ◽

H. Ecke ◽

A. Lagerkvist ◽

W. Calmano

Keyword(s):

Hexavalent Chromium ◽

Electrochemical Process ◽

Anaerobic Reduction

Download Full-text

Bioreduction and Bioremoval of Hexavalent Chromium by Genetically Engineered Strains (Escherichia Coli MT2A and Escherichia Coli MT3)

10.21203/rs.3.rs-710686/v1 ◽

2021 ◽

Author(s):

Şeyma Akkurt ◽

Merve Oğuz ◽

Aysel Alkan Uçkun

Keyword(s):

Escherichia Coli ◽

Electron Microscope ◽

Aqueous Solutions ◽

Hexavalent Chromium ◽

Effective Strain ◽

Scanning Transmission Electron Microscope ◽

Genetically Engineered ◽

High Rate ◽

Bacterial Cells ◽

Sem Images

Abstract Studies on the removal of toxic metals from water by genetic engineering applications are becoming more and more diverse. Especially by the expression of cysteine and thiol rich proteins such as metallothioneins in bacterial cells, a high rate of removal of metal ions from the environment is ensured. In this study, we evaluated the removal and reduction of hexavalent chromium Cr(VI)from aqueous solutions with the recombinant strains obtained by cloning the human metallothioneinsMT2A and MT3 into Escherichia coli Jm109.E. coli MT2A was the most effective strain in both Cr(VI) removal (89%in 25 mg/L Cr(VI) application) and Cr(VI) reduction (76%in 25 mg/L Cr(VI) application).Cr(VI) adsorbed per dry cell (at 25 mg/L) were 17 mg/g, 22 mg/g and 19 mg/g for Jm109, MT2A and MT3, respectively. Scanning electron microscope (SEM) images showed that the morphological structures of Cr(VI)treated cells were significantly damaged compared to control cells. Scanning transmission electron microscope (STEM) images showed black spots in the cytoplasm of cells treated with Cr(VI).From the shifts in the Fourier transform infrared spectroscopy analysis (FTIR) spectra of the cells treated with Cr(VI) compared to the control cells, it was determined that the groups interacting with Cr were amino, hydroxyl, methyl and sulfhydryl. When all these experimental data were evaluated together, it was concluded that all three species were effective in removing Cr(VI) from aqueous solutions and MT2A strain could be used as the most effective biotechnological tool.

Download Full-text

Effect of piperacillin on morphology and viability of gram-negative bacteria

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111203 ◽

1984 ◽

Vol 42 ◽

pp. 218-219

Author(s):

R. H. Liss

Keyword(s):

Inhibitory Concentration ◽

Cytoplasmic Membrane ◽

Drug Binding ◽

Gram Negative Bacteria ◽

Bacterial Cells ◽

Drug Induced ◽

Penicillin Binding Proteins ◽

Lactam Antibiotic ◽

Drug Free ◽

Tube Dilution

Piperacillip (PIP) is b-[D(-)-α-(4-ethy1-2,3-dioxo-l-piperzinylcar-bonylamino)-α-phenylacetamido]-penicillanate. The broad spectrum semisynthetic β-lactam antibiotic is believed to effect bactericidal activity through its affinity for penicillin-binding proteins (PBPs), enzymes on the bacterial cytoplasmic membrane that control elongation and septation during cell growth and division. The purpose of this study was to correlate penetration and binding of 14C-PIP in bacterial cells with drug-induced lethal changes assessed by microscopic, microbiologic and biochemical methods.The bacteria used were clinical isolates of Escherichia coli and Pseudomonas aeruginosa (Figure 1). Sensitivity to the drug was determined by serial tube dilution in Trypticase Soy Broth (BBL) at an inoculum of 104 organisms/ml; the minimum inhibitory concentration of piperacillin for both bacteria was 1 μg/ml. To assess drug binding to PBPs, the bacteria were incubated with 14C-PIP (5 μg/0.09 μCi/ml); controls, in drug-free medium.

Download Full-text

Attachment of oral bacteria to titanium surfaces: An SEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170074 ◽

1994 ◽

Vol 52 ◽

pp. 468-469

Author(s):

J. E. Laffoon ◽

R. L. Anderson ◽

J. C. Keller ◽

C. D. Wu-Yuan

Keyword(s):

Technical Problem ◽

Titanium Implant ◽

Oral Bacteria ◽

Bacterial Cells ◽

Thin Sections ◽

Surface Ultrastructure ◽

Sem Study ◽

Key Factor ◽

Titanium Surfaces

Titanium (Ti) dental implants have been used widely for many years. Long term implant failures are related, in part, to the development of peri-implantitis frequently associated with bacteria. Bacterial adherence and colonization have been considered a key factor in the pathogenesis of many biomaterial based infections. Without the initial attachment of oral bacteria to Ti-implant surfaces, subsequent polymicrobial accumulation and colonization leading to peri-implant disease cannot occur. The overall goal of this study is to examine the implant-oral bacterial interfaces and gain a greater understanding of their attachment characteristics and mechanisms. Since the detailed cell surface ultrastructure involved in attachment is only discernible at the electron microscopy level, the study is complicated by the technical problem of obtaining titanium implant and attached bacterial cells in the same ultra-thin sections. In this study, a technique was developed to facilitate the study of Ti implant-bacteria interface.Discs of polymerized Spurr’s resin (12 mm x 5 mm) were formed to a thickness of approximately 3 mm using an EM block holder (Fig. 1). Titanium was then deposited by vacuum deposition to a film thickness of 300Å (Fig. 2).

Download Full-text