Mixed Culture Electrochemically Active Biofilms And Their Microscopic And Spectroelectrochemical Studies, Mohammad Mansoob Khan Dr, S. A. Ansari, J. H. Lee, J. Lee, M. H. Cho
Feb 2014
Mixed Culture Electrochemically Active Biofilms And Their Microscopic And Spectroelectrochemical Studies, Mohammad Mansoob Khan Dr, S. A. Ansari, J. H. Lee, J. Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
Mixed culture electrochemically active biofilms (EABs) were developed on carbon paper using a sludge with mixed culture bacteria for microscopic and pectroelectrochemical studies because a naturally mixed culture bacterial strain is more applicable than a pure culture strain. EAB development was confirmed by microbial fuel cells (MFCs) by obtaining a constant increase in potential (∼0.36 V). Microscopic and spectroscopic studies showed that a mixed culture EABs formed on the support. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS), which are nondestructive voltammetry techniques, indicated that the EABs could be source of electrons and used effectively for …
Forisome Performance In Artificial Sieve Tubes, Michael Knoblauch, Mike Stubenrauch, Aart J.E. Van Bel, Winfried S. Peters
Mar 2012
Forisome Performance In Artificial Sieve Tubes, Michael Knoblauch, Mike Stubenrauch, Aart J.E. Van Bel, Winfried S. Peters
Winfried S. Peters
In the legume phloem, sieve element occlusion (SEO) proteins assemble into Ca2+-dependent contractile bodies. These forisomes presumably control phloem transport by forming reversible sieve tube plugs. This function, however, has never been directly demonstrated, and appears questionable as forisomes were reported to be too small to plug sieve tubes, and failed to block flow efficiently in artificial microchannels. Moreover, plugs of SEO-related proteins in Arabidopsis sieve tubes do not affect phloem translocation. We improved existing procedures for forisome isolation and storage, and found that the degree of Ca2+-driven deformation that is possible in forisomes of Vicia faba, the standard …
Münch, Morphology, Microfluidics – Our Structural Problem With The Phloem [Review Article], Michael Knoblauch, Winfried S. Peters
Aug 2010
Münch, Morphology, Microfluidics – Our Structural Problem With The Phloem [Review Article], Michael Knoblauch, Winfried S. Peters
Winfried S. Peters
The sieve tubes of the phloem are enigmatic structures. Their role as channels for the distribution of assimilates was established in the 19th century, but their sensitivity to disturbations has hampered the elucidation of their transport mechanisms and its regulation ever since. Ernst Münch's classical monograph of 1930 is generally regarded as the first coherent theory of phloem transport, but the ‘Münchian’ pressure flow mechanism had been discussed already before the turn of the century. Münch's impact rather rested on his simple physical models of the phloem that visualized pressure flow in an intuitive way, and we argue that the …
Anisotropic Contraction In Forisomes: Simple Models Won't Fit, Winfried Peters, Michael Knoblauch, Stephen Warmann, William Pickard, Amy Shen
Mar 2008
Anisotropic Contraction In Forisomes: Simple Models Won't Fit, Winfried Peters, Michael Knoblauch, Stephen Warmann, William Pickard, Amy Shen
Winfried S. Peters
Forisomes are ATP-independent, Ca2+-driven contractile protein bodies acting as reversible valves in the phloem of plants of the legume family. Forisome contraction is anisotropic, as shrinkage in length is associated with radial expansion and vice versa. To test the hypothesis that changes in length and width are causally related, we monitored Ca2+- and pH-dependent deformations in the exceptionally large forisomes of Canavalia gladiata by high-speed photography, and computed time-courses of derived geometric parameters (including volume and surface area). Soybean forisomes, which in the resting state resemble those of Canavalia geometrically but have less than 2% of the volume, were also …
Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard
Jun 2007
Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard
Winfried S. Peters
Background and Aims Forisomes are Ca2+-dependent contractile protein bodies that form reversible plugs in sieve tubes of faboid legumes. Previous work employed Vicia faba forisomes, a not entirely unproblematic experimental system. The aim of this study was to seek to establish a superior model to study these intriguing actuators.
Methods Existing isolation procedures were modified to study the exceptionally large, tailed forisomes of Canavalia gladiata by differential interference contrast microscopy in vitro. To analyse contraction/expansion kinetics quantitatively, a geometric model was devised which enabled the computation of time-courses of derived parameters such as forisome volume from simple parameters readily determined …
Forisome Based Biomimetic Smart Materials, Amy Shen, Benjamin Hamlington, Michael Knoblauch, Winfried Peters, William Pickard
Jun 2006
Forisome Based Biomimetic Smart Materials, Amy Shen, Benjamin Hamlington, Michael Knoblauch, Winfried Peters, William Pickard
Winfried S. Peters
With the discovery in plants of the proteinaceous forisome crystalloid (Knoblauch, et al. 2003), a novel, non-living, ATP-independent biological material became available to the designer of smart materials for advanced actuating and sensing. The in vitro studies of Knoblauch, et al. show that forisomes (2-4 micron wide and 10-40 micron long) can be repeatedly stimulated to contract and expand anisotropically by shifting either the ambient pH or the ambient calcium ion concentration. Because of their unique abilities to develop and reverse strains greater than 20% in time periods less than one second, forisomes have the potential to outperform current smart …
Prospective Energy Densities In The Forisome, A New Smart Material, William Pickard, Michael Knoblauch, Winfried Peters, Amy Shen
Dec 2005
Prospective Energy Densities In The Forisome, A New Smart Material, William Pickard, Michael Knoblauch, Winfried Peters, Amy Shen
Winfried S. Peters
The forisome is a protein structure of plants which, in low Ca2+ solutions, assumes a crystalline condensed conformation and, at high Ca2+, swells to a dispersed conformation; this transition has been attributed to electrostatic deformation of protein “modules”. Forisomes could become an important smart material if the energy density of transformation approached 1 MJ m−3. Quantitation of the forisome as a charged porous continuum permeated by electrolyte fails by orders of magnitude to achieve this energy density electrostatically. However, condensed → dispersed transitions can be visualized alternatively: (i) an ionic bond near the surface of a forisome crystal dissolves to …
Biomimetic Actuators: Where Technology And Cell Biology Merge [Review Article], Michael Knoblauch, Winfried Peters
Nov 2004
Biomimetic Actuators: Where Technology And Cell Biology Merge [Review Article], Michael Knoblauch, Winfried Peters
Winfried S. Peters
The structural and functional analysis of biological macromolecules has reached a level of resolution that allows mechanistic interpretations of molecular action, giving rise to the view of enzymes as molecular machines. This machine analogy is not merely metaphorical, as bio-analogous molecular machines actually are being used as motors in the fields of nanotechnology and robotics. As the borderline between molecular cell biology and technology blurs, developments in the engineering and material sciences become increasingly instructive sources of models and concepts for biologists. In this review, we provide a – necessarily selective – summary of recent progress in the usage of …
Forisomes, A Novel Type Of Ca2+-Dependent Contractile Protein Motor [Review Article], Michael Knoblauch, Winfried Peters
Apr 2004
Forisomes, A Novel Type Of Ca2+-Dependent Contractile Protein Motor [Review Article], Michael Knoblauch, Winfried Peters
Winfried S. Peters
This paper has no abstract; this is the first paragraph. Motility of cell components in both animal and plant cells is mostly based on the movement of motor proteins along actin filaments or microtubules [Boal, 2002]. The dominance of ATP hydrolysis as the energy source for such movements is so complete, that modern textbooks define “motor proteins” as nucleoside triphosphate-dependent actuators [e.g., Alberts et al., 2002]. In only one known case, a reversible mechanism of cell motility is driven by the interaction of Ca2+ and the responsive protein(s). Some sessile ciliates control the effective length of their stalk by means …
Atp-Independent Contractile Proteins From Plants, Michael Knoblauch, Gundula Noll, Torsten Müller, Dirk Prüfer, Ingrid Schneider-Hüther, Dörte Scharner, Aart Van Bel, Winfried Peters
Aug 2003
Atp-Independent Contractile Proteins From Plants, Michael Knoblauch, Gundula Noll, Torsten Müller, Dirk Prüfer, Ingrid Schneider-Hüther, Dörte Scharner, Aart Van Bel, Winfried Peters
Winfried S. Peters
This paper has no abstract; this is the first paragraph. Emerging technologies are creating increasing interest in smart materials that may serve as actuators in micro- and nanodevices. Mechanically active polymers currently studied include a variety of materials. ATP-driven motor proteins, the actuators of living cells, possess promising characteristics, but their dependence on strictly defined chemical environments can be disadvantagous. Natural proteins that deform reversibly by entropic mechanisms might serve as models for artificial contractile polypeptides with useful functionality, but they are rare. Protein bodies from sieve elements of higher plants provide a novel example. sieve elements form microfluidics systems …
