The Lubrication Properties of Microbial Cells and their Biopolymers

2015 ◽  
Vol 794 ◽  
pp. 285-291
Author(s):  
Marvin Redetzky ◽  
Andreas Rabenstein ◽  
Benedikt Seidel ◽  
Ekkard Brinksmeier
Keyword(s):  
Extracellular Polymeric Substances ◽  
Microbial Cell ◽  
Metalworking Fluids ◽  
Premature Failure ◽  
Cell Counts ◽  
Water Based ◽  
Cell Components ◽  
Big Cell ◽  
High Level ◽  
Lubrication Properties

Many machining operations e.g. turning, milling or grinding are dependent on the application of water-based metalworking fluids (MWF) which contribute significantly to their high level of performance. MWF in-use are exposed to a microbial contamination, which leads to a deterioration of water-based MWF components and can cause a premature failure of the whole coolant system. Expensive monitoring and the addition of biocides are needed to maintain the MWF quality and to reduce the microbial load, regardless of the potential risk for health and environment. To overcome these limitations, the paradigm shift of using microorganisms as a replacement for conventional MWF is investigated in this paper. Microbial cell components and some microbial inclusions are comparable to conventional MWF components like e.g. fatty acids or sulfur compounds. Due to this fact, it is possible to create a regenerative system on a microbiological basis for the substitution of conventional MWF components. In preliminary tribological investigations the basic lubrication properties of microorganisms and their potential as a replacement for conventional MWF were shown. The presented approach intends to investigate the influence of microbial cell counts, cells size and extracellular polymeric substances (EPS) on the lubrication behavior respectively. The results of the tribological tests show that especially microorganisms with a big cell volume or a high EPS productivity exhibit superior Brugger-values (up to 174%) compared to a highly concentrated conventional MWF (emulsion 10%) and indicate the great potential of microorganisms as a replacement for conventional MWF.

Microorganisms as a Replacement for Metal Working Fluids

2014 ◽  
Vol 966-967 ◽  
pp. 357-364 ◽  
Author(s):  
Marvin Redetzky ◽  
Andreas Rabenstein ◽  
B. Palmowski ◽  
Ekkard Brinksmeier
Keyword(s):  
Paradigm Shift ◽  
Microbial Growth ◽  
Microbial Contamination ◽  
Mineral Oil ◽  
Metal Working ◽  
Technical Performance ◽  
Cell Counts ◽  
Metalworking Fluid ◽  
Water Based ◽  
Lubrication Properties

Most of the several billion liters of metalworking fluid (MWF) used worldwide and annually are water-based and thus prone to a microbial contamination. The microbial growth leads to a deterioration and therefore to a loss of quality and technical performance. In most cases, biocides, which pose a potential risk to health and environment, are used to reduce the microbial load. To avoid these limitations, the paradigm shift of using microorganisms in a positive way in a manufacturing process as a lubricant is investigated in this paper. Some microorganisms are able to synthesize equivalent MWF components like e.g. fatty acids or sulfur compounds. Due to this fact, it is possible to create a regenerative system on a microbiological basis for the substitution of mineral oil containing MWF components. To demonstrate the lubrication potential of bacteria, preliminary investigations were conducted on a Brugger-tribotester. Against this background, the approach presented here intends to investigate the lubrication properties of special microorganisms and the influence of the microbial cell counts on the lubrication behavior respectively. The results of the tribological tests show that the microbial-suspensions exhibit Brugger-values as high as highly concentrated conventional MWF and indicate the potential to replace these respective components.

Soft EHL Lubrication of Complex Multiphase Fluids

2005 ◽  
Author(s):  
J. de Vicente ◽  
H. A. Spikes ◽  
J. R. Stokes
Keyword(s):  
Complex Fluids ◽  
Steel Ball ◽  
Film Forming ◽  
Wide Range ◽  
Multiphase Fluids ◽  
Water Based ◽  
Complex Rheology ◽  
Lubrication Properties ◽  
Flat Contact ◽  
Ehl Lubrication

The lubrication properties of a series of multiphase water-based fluids of complex rheology and microstructure, including o/w emulsions, have been studied in a rolling-sliding steel ball-on-elastomer flat contact. The results show that friction curves of Newtonian fluids made over a wide range of entrainment speeds and viscosity can be used to identify the prevailing mechanisms of lubrication for more complex fluids and, for emulsions, to show the predominant film-forming phase.

scholarly journals Infeksi Biofilm Bakterial

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Heriyannis . Homenta
Keyword(s):  
Cystic Fibrosis ◽  
Antibiotic Resistance ◽  
Cell Surface ◽  
Medical Devices ◽  
Extracellular Polymeric Substances ◽  
Bacterial Endocarditis ◽  
Bacterial Biofilm ◽  
Microbial Cell ◽  
Space And Time

Abstract: Biofilm is the unity of microbial cell surface surrounded by a matrix of extracellular polymeric substances (EPS). Bacteria composing the biofilm are heterogeneous in space and time. This biofilm continues to grow influenced by internal and external processes. Moreover, biofilm can be found on the surface of medical devices, as well as in bacterial endocarditis and cystic fibrosis. Biofilm that is already formed can lead to antibiotic resistance.Keywords: infections, bacterial biofilm, antibiotic resistance Abstrak: Biofilm merupakan kesatuan dari permukaan sel mikroba yang dilingkupi oleh matriks substansi polimerik ekstraseluler. Bakteri yag menyusun biofilm bersifat heterogen dalam ruang dan waktu. Biofilm terus berkembang yang dipengaruhi oleh proses internal dan eksternal. Biofilm dapat ditemukan pada permukaan alat-alat medis, endokarditis bakterial, dan kistik fibrosis. Biofilm yang telah terbentuk dapat menyebabkan resistensi antibiotik. Kata kunci: infeksi, biofilm bakterial, resistensi antibiotik

Synthesis of polyacrylamide-wrapped carbon nanotubes and their lubrication properties as water-based fluids

2007 ◽  
Vol 106 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Yifeng Liu ◽  
Wenchao Guan ◽  
Xuefeng Li ◽  
Mingxing Huang
Keyword(s):  
Carbon Nanotubes ◽  
Water Based ◽  
Lubrication Properties

Patch testing with components of water-based metalworking fluids: results of a multicentre study with a second series

2006 ◽  
Vol 55 (6) ◽  
pp. 322-329 ◽  
Author(s):  
Johannes Geier ◽  
Holger Lessmann ◽  
Detlef Becker ◽  
Magnus Bruze ◽  
Peter J. Frosch ◽  
...  
Keyword(s):  
Multicentre Study ◽  
Patch Testing ◽  
Metalworking Fluids ◽  
Water Based

Study on Lubrication Properties of Carboxymethyl Cellulose as a Novel Additive in Water-Based Stock

2005 ◽  
Author(s):  
Wenchao Guan ◽  
Gang Ke ◽  
Changyu Tang ◽  
Yifeng Liu
Keyword(s):  
Molecular Structure ◽  
Renewable Resources ◽  
Carboxymethyl Cellulose ◽  
Base Stock ◽  
Cellulose Derivatives ◽  
Frictional Pair ◽  
Water Based ◽  
Lubrication Properties ◽  
Scanning Electron ◽  
Antiwear Ability

This paper reports cellulose derivative—carboxymethyl cellulose (CMC) as a novel additive in a water-based stock (water content above 95 wt.%). Cellulose is one of the richest renewable resources on earth and has many peculiar qualities. Several cellulose derivatives such as CMC can easily dissolve in water and form stable thin film on the surface of metal. Several apparatus involving four-ball machine were used to investigate lubrication properties of the based stock containing CMC. The worn surfaces were observed with a scanning electron microscope. As the results, the anti-wear ability of the base stock is effectively increased by addition of a small amount (0.7 wt.%) of CMC. The additive with peculiar molecular structure contributes to abate the adhesion and scuffing of frictional pair effectively, hence improves the antiwear ability of the base stock. Thus CMC provides a potential application in the field of water-based stock lubrication.

CMV Specific T Cells Prevent Progression From Low to High Level Viremia In D+R+ but Not D-R+ Patients.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4532-4532
Author(s):  
Mette Hoegh-Petersen ◽  
Lina Roa ◽  
Yiping Liu ◽  
Feng Zhou ◽  
Alejandra Ugarte-Torres ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Conflicts Of Interest ◽  
Spontaneous Resolution ◽  
Cell Transplant ◽  
Low Level ◽  
Peak Viremia ◽  
Cell Counts ◽  
High Level ◽  
Ifnγ And Tnfα

Abstract Abstract 4532 Background. Cytomegalovirus (CMV) reactivates (becomes detectable in blood) in most seropositive hematopoietic cell transplant (HCT) recipients. In some reactivating patients, low level viremia (<50,000 DNA copies/ml plasma, ie, less than our institutional threshold for preemtive therapy) progresses to high level viremia or CMV disease, which is potentially fatal. We hypothesized that low level viremia progresses in patients with low specific T cell counts and spontaneously resolves in patients with high specific T cell counts. Methods. In 30 CMV seropositive HCT recipients monitored weekly for reactivation by real-time PCR, blood was drawn for specific T cell counts within 4 days from the first episode of low level viremia. Fourteen patients received grafts from seropositive donors (D+R+), and 16 patients from seronegative donors (D-R+). Mononuclear cells were stimulated overnight with CMV lysate, pp65 overlapping peptides, no stimulus (negative control) or staphylococcal enterotoxin B (positive control). T cells producing IFNγ, TNFα and/or IL2 were enumerated by flow cytometry. Results. Among D+R+ patients, counts of CMV lysate and pp65 specific CD4 T cells producing IFNγ and TNFα (and not IL2) were higher in patients with spontaneous resolution than patients with progression (p=0.02 for CMV lysate, p=0.004 for pp65). Also, there was an inverse correlation between pp65 specific CD8 T cells producing IFNγ and TNFα and peak viremia (r=-0.94, p=0.005) in D+R+ patients who progressed to high level viremia/disease. In contrast, among D-R+ patients, CMV lysate and pp65 specific T cell counts were similar in patients with spontaneous resolution and patients with progression, and there was no correlation between specific T cell counts and peak viremia. Conclusion. CMV specific T cells play a role in preventing progression from low to high level CMV reactivation/disease in D+R+ patients. Other immune mechanisms (eg, NK cells?) play the role in D-R+ patients. Disclosures: No relevant conflicts of interest to declare.

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