Morphological and diffusional changes in L. lactis biofilms

2020 ◽  
Author(s):  
Jonas Chodorski ◽  
Jan Hauth ◽  
Andreas Wirsen ◽  
Roland Ulber
Keyword(s):  
Collaborative Research ◽  
Extracellular Polymeric Substances ◽  
Downstream Processing ◽  
Diffusion Profile ◽  
Industrial Applications ◽  
Toxic Substances ◽  
Way Of Life ◽  
3D Space ◽  
Diffusion Constants ◽  
Biofilm Structure

<p>Through their special way of life, biofilms have several advantages over organisms in planktonic growth. By being surface-attached and producing a mass of extracellular polymeric substances (EPS), microorganisms possess inherent self-immobilization, which decreases the expenditure of downstream processing in industrial applications. Furthermore, they are more resilient against environmental stress and toxic substances, such as antibiotics. An important factor here is diffusion, of substrate into the biofilm and metabolites through and out of the biofilm; however, these mechanisms are still poorly understood. By utilizing a specially developed diffusion model and CLSM FRAP microscopy, diffusion constants in the living, fully hydrated biofilm of <em>L. lactis</em> during development can be assessed. With it, heatmaps of diffusional constants and finally a diffusion profile encompassing a true 3D space of the living biofilm in growth can be generated. With those, possible hotspots and changes of diffusion inside the biofilm structure with regard to changing cultivation conditions and the substratum can be identified, thus furthering our understanding of diffusion in biofilms and how they react to their environment.</p> <p>The project is funded by the DFG (UL 170/14-1) and the collaborative research center (SFB) 926 on “microscale morphology of component surfaces” (MICOS).</p>

Understanding Intercultural Socialization and Identity Development of International Students Through Duoethnography

2021 ◽  
pp. 1-20
Author(s):  
Glory Ovie ◽  
Lena Barrantes
Keyword(s):  
International Students ◽  
Identity Development ◽  
Research Methodology ◽  
Collaborative Research ◽  
The Other ◽  
Way Of Life ◽  
Personal Stories ◽  
The Face

This chapter looks at how two international PhD students (re)constructed and (re)negotiated their identities, and intercultural socialization through the sharing their personal stories and experiences. This chapter employed a duoethnography research methodology. Duoethnography is a collaborative research methodology in which two or more researchers engage in a dialogue on their disparate histories in a given phenomenon. The use of duoethnography allowed the researchers to revisit their lives as sites of research to determine how their different experiences and backgrounds informed the (re)construction and (re)negotiation of their identities in the face of multiple and competing identities and their subsequent participation in the new culture. Through this process, the researchers acted as the foil for the Other, challenging the Other to reflect in a deeper, more relational and authentic manner as they sought to achieve a balance between participating in a new way of life and maintaining their cultural and personal identities.

scholarly journals Recovery profile of anaerobic ammonium oxidation (anammox) bacteria inhibited by ZnO nanoparticles

2021 ◽  
Author(s):  
Safiye Can ◽  
Tugba Sari ◽  
Deniz Akgul
Keyword(s):  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Recovery Period ◽  
Industrial Applications ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Zno Nps ◽  
Treatment Processes ◽  
Recovery Profile ◽  
Different Doses

Abstract The potential effects of nanoparticles (NPs) on biological treatment processes have become significant due to their increasing industrial applications. The purpose of this research was to investigate the self-recovery ability of anammox bacteria following to acute ZnO NPs toxicity. In this context, a 2-liter lab-scale anammox reactor was operated for 550 days to enrich the biomass required to the batch exposure tests. Anammox culture was firstly exposed to four different doses of ZnO NPs (50, 75, 100 and 200 mg/L) for 24 h. Then, the ZnO NPs were removed and self-recovery performance of the anammox bacteria was assessed by evaluating the nitrogen removal capacities for 72 h. Besides the nitrogen removal performance, extracellular polymeric substances (EPS) production was also detected to deeply understand the response of the enriched anammox culture against ZnO NPs exposure. The results revealed that, sudden and high load of ZnO NPs (100 and 200 mg/L) resulted in persistent impairment on the nitrogen removal performance of the enriched anammox culture. However, relatively lower doses (50 and 75 mg/L) caused deceleration of the nitrogen removal performance during the recovery period. In addition, EPS content in the reactor decreased along with escalating load of ZnO NPs.

scholarly journals Algorithm to obtain inverse kinematics matrix from the 3D curve and to apply to glue shoe sole

2014 ◽  
Vol 17 (2) ◽  
pp. 5-17
Author(s):  
Thanh Le Nhu Ngoc Ha ◽  
Tung Thanh Luu ◽  
Tien Tan Nguyen
Keyword(s):  
Pid Controller ◽  
Inverse Kinematics ◽  
Interpolation Method ◽  
Industrial Applications ◽  
Tracking Performance ◽  
End Effector ◽  
Reference Path ◽  
3D Space ◽  
Position And Orientation ◽  
Arbitrary Curve

Nowadays, manipulator is widely used in industrial applications. The trajectories of manipulator are more and more complicated. In order to do good tracking performance, the end effector position and orientation have to be determined. This paper describes a method to determine position and orientation of manipulator’s end effector base on a reference path. This method will be applied for manipulator 6 DOF to glue shoe sole. Firstly, assume the reference path is arbitrary curve, the path was then discrete to become multi-point. Secondly, the roll – pitch – yaw vectors of the end effector will be determined at each point. Finally, Euler angles and interpolation method in 3D space will be applied to determine inverse kinematics matrix of manipulator for each point on the reference path. In addition, this paper also gives an example of reference path of shoe sole to apply the presented method. To verify the tracking performance of manipulator and reference path, a PID controller was designed for simulation. The result of simulation proved the correction of the algorithm.

scholarly journals Model System for Growing and Quantifying Streptococcus pneumoniae Biofilms In Situ and in Real Time

2004 ◽  
Vol 70 (8) ◽  
pp. 4980-4988 ◽  
Author(s):  
R. M. Donlan ◽  
J. A. Piede ◽  
C. D. Heyes ◽  
L. Sanii ◽  
R. Murga ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Extracellular Polymeric Substances ◽  
Viable Cell ◽  
Protein Band ◽  
Biofilm Reactor ◽  
Cell Counts ◽  
Biofilm Structure ◽  
Kinetics Of ◽  
Over Time

ABSTRACT Streptococcus pneumoniae forms biofilms, but little is known about its extracellular polymeric substances (EPS) or the kinetics of biofilm formation. A system was developed to enable the simultaneous measurement of cells and the EPS of biofilm-associated S. pneumoniae in situ over time. A biofilm reactor containing germanium coupons was interfaced to an attenuated total reflectance (ATR) germanium cell of a Fourier transform infrared (FTIR) laser spectrometer. Biofilm-associated cells were recovered from the coupons and quantified by total and viable cell count methods. ATR-FTIR spectroscopy of biofilms formed on the germanium internal reflection element (IRE) of the ATR cell provided a continuous spectrum of biofilm protein and polysaccharide (a measure of the EPS). Staining of the biofilms on the IRE surface with specific fluorescent probes provided confirmatory evidence for the biofilm structure and the presence of biofilm polysaccharides. Biofilm protein and polysaccharides were detected within hours after inoculation and continued to increase for the next 141 h. The polysaccharide band increased at a substantially higher rate than did the protein band, demonstrating increasing coverage of the IRE surface with biofilm polysaccharides. The biofilm total cell counts on germanium coupons stabilized after 21 h, at approximately 105 cells per cm2, while viable counts decreased as the biofilm aged. This system is unique in its ability to detect and quantify biofilm-associated cells and EPS of S. pneumoniae over time by using multiple, corroborative techniques. This approach could prove useful for the study of biofilm processes of this or other microorganisms of clinical or industrial relevance.

scholarly journals Novel Strategies for Upstream and Downstream Processing of Tannin Acyl Hydrolase

2011 ◽  
Vol 2011 ◽  
pp. 1-20 ◽  
Author(s):  
Luis V. Rodríguez-Durán ◽  
Blanca Valdivia-Urdiales ◽  
Juan C. Contreras-Esquivel ◽  
Raúl Rodríguez-Herrera ◽  
Cristóbal N. Aguilar
Keyword(s):  
Gallic Acid ◽  
Downstream Processing ◽  
Industrial Applications ◽  
Culture Conditions ◽  
Negative Effects ◽  
Nonaqueous Media ◽  
Tannery Effluents ◽  
High Production ◽  
High Production Cost ◽  
Gallic Acid Esters

Tannin acyl hydrolase also referred as tannase is an enzyme with important applications in several science and technology fields. Due to its hydrolytic and synthetic properties, tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, for the production of gallic acid from tannin-rich materials, the elucidation of tannin structure, and the synthesis of gallic acid esters in nonaqueous media. However, industrial applications of tannase are still very limited due to its high production cost. Thus, there is a growing interest in the production, recovery, and purification of this enzyme. Recently, there have been published a number of papers on the improvement of upstream and downstream processing of the enzyme. These papers dealt with the search for new tannase producing microorganisms, the application of novel fermentation systems, optimization of culture conditions, the production of the enzyme by recombinant microorganism, and the design of efficient protocols for tannase recovery and purification. The present work reviews the state of the art of basic and biotechnological aspects of tannin acyl hydrolase, focusing on the recent advances in the upstream and downstream processing of the enzyme.

Agarose hydrogels as EPS models

2001 ◽  
Vol 43 (6) ◽  
pp. 169-175 ◽  
Author(s):  
M. Strathmann ◽  
T. Griebe ◽  
H.-C. Flemming
Keyword(s):  
Extracellular Polymeric Substances ◽  
Chemical Properties ◽  
Microscopic Investigation ◽  
Molecular Probes ◽  
Toxic Substances ◽  
Protective Effects ◽  
Water Binding ◽  
Agarose Beads ◽  
Composition And Structure ◽  
The Stability

For investigating the influence of extracellular polymeric substances (EPSs) on biofilm properties, artificial models of defined composition and structure can be very helpful. Different immobilised cell systems can be useful in the fitting of experimental results. Two different types of artificial EPS matrix model were developed earlier. Homogeneous agarose beads (50-500 μm diameter) and porous beads (260 μm mean diameter) containing pores with diameters from 10 to 80 μm (28 μm on average), allowed the embedding of cells, particles and typical EPS matrix components such as proteins and polysaccharides. In this paper, some physico-chemical properties of the artificial EPS matrices were described and compared with results known from natural EPS. The stability of the artificial matrix polymer against solution in the aqueous medium was studied in batch experiments. The water binding and water retaining capabilities of the EPS models were investigated by drying and re-swelling experiments. The simulation of protective effects of the artificial EPS matrix against toxic substances like biocides in comparison to such known protective effects of the EPS of native biofilms were proved by the application of sodium hypochlorite (0.5 mg/l, 30 min) and subsequent microscopic investigation of the cell population after LIVE/DEAD staining (Molecular Probes).

On the Diffusion Profile at the Brazed Interface between Active Filler Metal and CVD Diamond Plates

2013 ◽  
Vol 334-335 ◽  
pp. 203-206 ◽  
Author(s):  
Osmar Roberto Bagnato ◽  
Fernanda Regina Francisco ◽  
Evaldo Jose Corat ◽  
Joao Roberto Moro ◽  
Diego Llopes
Keyword(s):  
Filler Metal ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Diffusion Profile ◽  
Industrial Applications ◽  
Infrared Light ◽  
Metallic Substrates ◽  
Optical Applications ◽  
Made In

Diamonds films have characteristics that are interesting for many optical applications, such as transparency to ultraviolet, visible and infrared light. These applications include use in detectors and windows in processes that involve high temperatures, microelectronics applications and wear-resistant components [. Polycrystalline diamond films can be made in the vapor phase at low-pressure, relatively low temperatures and in the form of auto-supported films, using the CVD process (Chemical Vapor Deposition) [. These films have a significant number of industrial applications, but often have problems with adhesion to metallic substrates. Diamond films can be deposited directly over some metals, but other techniques, such as brazing, can be used [.

scholarly journals Helicobacter pyloriBiofilm Formation and Its Potential Role in Pathogenesis

2018 ◽  
Vol 82 (2) ◽  
Author(s):  
Skander Hathroubi ◽  
Stephanie L. Servetas ◽  
Ian Windham ◽  
D. Scott Merrell ◽  
Karen M. Ottemann
Keyword(s):  
Extracellular Polymeric Substances ◽  
Antimicrobial Treatment ◽  
Gastric Ulcers ◽  
Chronic Infections ◽  
Content Type ◽  
Mucosal Layer ◽  
Urease Production ◽  
H Pylori ◽  
Biofilm Structure

SUMMARYDespite decades of effort,Helicobacter pyloriinfections remain difficult to treat. Over half of the world's population is infected byH. pylori, which is a major cause of duodenal and gastric ulcers as well as gastric cancer. During chronic infection,H. pylorilocalizes within the gastric mucosal layer, including deep within invaginations called glands; thanks to its impressive ability to survive despite the harsh acidic environment, it can persist for the host's lifetime. This ability to survive and persist in the stomach is associated with urease production, chemotactic motility, and the ability to adapt to the fluctuating environment. Additionally, biofilm formation has recently been suggested to play a role in colonization. Biofilms are surface-associated communities of bacteria that are embedded in a hydrated matrix of extracellular polymeric substances. Biofilms pose a substantial health risk and are key contributors to many chronic and recurrent infections. This link between biofilm-associated bacteria and chronic infections likely results from an increased tolerance to conventional antibiotic treatments as well as immune system action. The role of this biofilm mode in antimicrobial treatment failure andH. pylorisurvival has yet to be determined. Furthermore, relatively little is known about theH. pyloribiofilm structure or the genes associated with this mode of growth. In this review, therefore, we aim to highlight recent findings concerningH. pyloribiofilms and the molecular mechanism of their formation. Additionally, we discuss the potential roles of biofilms in the failure of antibiotic treatment and in infection recurrence.

scholarly journals Membrane Purification Techniques for Recovery of Succinic Acid Obtained from Fermentation Broth during Bioconversion of Lignocellulosic Biomass: Current Advances and Future Perspectives

2021 ◽  
Vol 13 (12) ◽  
pp. 6794
Author(s):  
Olawumi O. Sadare ◽  
Olayile Ejekwu ◽  
Moloko F. Moshokoa ◽  
Monsurat O. Jimoh ◽  
Michael O. Daramola
Keyword(s):  
Succinic Acid ◽  
Lignocellulosic Biomass ◽  
Fermentation Broth ◽  
Short Review ◽  
Downstream Processing ◽  
Critical Issue ◽  
Industrial Applications ◽  
Global Market ◽  
Green Technologies ◽  
One Pot

Recently, the bioconversion of biomass into biofuels and biocommodities has received significant attention. Although green technologies for biofuel and biocommodity production are advancing, the productivity and yield from these techniques are low. Over the past years, various recovery and purification techniques have been developed and successfully employed to improve these technologies. However, these technologies still require improvement regarding the energy-consumption-related costs, low yield and product purity. In the context of sustainable green production, this review presents a broad review of membrane purification technologies/methods for succinic acid, a biocommodity obtained from lignocellulosic biomass. In addition, a short overview of the global market for sustainable green chemistry and circular economy systems or zero waste approach towards a sustainable waste management is presented. Succinic acid, the available feedstocks for its production and its industrial applications are also highlighted. Downstream separation processes of succinic acid and the current studies on different downstream processing techniques are critically reviewed. Furthermore, critical analysis of membrane-based downstream processes of succinic acid production from fermentation broth is highlighted. A short review of the integrated-membrane-based process is discussed, as well, because integrating “one-pot” lignocellulosic bioconversion to succinic acid with downstream separation processing is considered a critical issue to address. In conclusion, speculations on outlook are suggested.

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