Rapid determination of fractal structure of bacterial assemblages in wastewater treatment: implications to process optimisation

1998 ◽  
Vol 38 (2) ◽  
pp. 9-15 ◽  
Author(s):  
J. Guan ◽  
T. D. Waite ◽  
R. Amal ◽  
H. Bustamante ◽  
R. Wukasch
Keyword(s):  
Wastewater Treatment ◽  
Fractal Structure ◽  
Structural Information ◽  
Rapid Determination ◽  
Fractal Dimensions ◽  
Structure Information ◽  
Treatment Processes ◽  
On Line ◽  
Bacterial Aggregates

A rapid method of determining the structure of aggregated particles using small angle laser light scattering is applied here to assemblages of bacteria from wastewater treatment systems. The structure information so obtained is suggestive of fractal behaviour as found by other methods. Strong dependencies are shown to exist between the fractal structure of the bacterial aggregates and the behaviour of the biosolids in zone settling and dewatering by both pressure filtration and centrifugation methods. More rapid settling and significantly higher solids contents are achievable for “looser” flocs characterised by lower fractal dimensions. The rapidity of determination of structural information and the strong dependencies of the effectiveness of a number of wastewater treatment processes on aggregate structure suggests that this method may be particularly useful as an on-line control tool.

VOC Fate Model Verification at Multiple Pulp Mill Wastewater Treatment Sites

1992 ◽  
Vol 26 (1-2) ◽  
pp. 407-415 ◽  
Author(s):  
D. A. Barton ◽  
J. J. McKeown ◽  
W. Chudyk
Keyword(s):  
Wastewater Treatment ◽  
Paper Industry ◽  
Pulp Mill ◽  
Pulp And Paper Industry ◽  
Model Verification ◽  
Initial Model ◽  
Gas Sampling ◽  
Treatment Processes ◽  
Fate Model

A model of organic compound removal by biological wastewater treatment processes receiving pulp and paper industry wastewaters has been developed and initial model verification performed at a single mill site. This paper presents the results of further model verification conducted at multiple mill sites, including replication of the original site. In addition, VOC losses at other unit processes are quantified. Activated sludge basin chloroform volatilization rates are predicted to within twelve percent of the measured rates. Predicted overall methanol removals are consistent with observed removals although difficulties encountered during off-gas sampling preclude determination of the extent of removal due to volatilization.

On-line estimation of unmeasured inputs for anaerobic wastewater treatment processes

2003 ◽  
Vol 11 (9) ◽  
pp. 1007-1019 ◽  
Author(s):  
Didier Theilliol ◽  
Jean-Christophe Ponsart ◽  
Jérôme Harmand ◽  
Cédric Join ◽  
Pascal Gras
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Wastewater Treatment ◽  
Treatment Processes ◽  
On Line

scholarly journals Integrated NMR and cryo-EM atomic-resolution structure determination of a half-megadalton enzyme complex

2018 ◽  
Author(s):  
Diego Gauto ◽  
Leandro Estrozi ◽  
Charles Schwieters ◽  
Gregory Effantin ◽  
Pavel Macek ◽  
...  
Keyword(s):  
Structure Determination ◽  
Protein Function ◽  
Structural Information ◽  
Magic Angle Spinning ◽  
Atomic Resolution ◽  
Magic Angle ◽  
Nmr Structure Determination ◽  
Structure Information ◽  
Resolution Structure

Atomic-resolution structure determination is the key requirement for understanding protein function. Cryo-EM and NMR spectroscopy both provide structural information, but currently cryo-EM does not routinely give access to atomic-level structural data, and, generally, NMR structure determination is restricted to small (<30 kDa) proteins. We introduce an integrated structure determination approach that simultaneously uses NMR and EM data to overcome the limits of each of these methods. The approach enabled determination of the high-resolution structure of the 468 kDa large dodecameric aminopeptidase TET2 to a precision and accuracy below 1 Angstrom by combining secondary-structure information obtained from near-complete magic-angle-spinning NMR assignments of the 39 kDa-large subunits, distance restraints from backbone amides and specifically labelled methyl groups, and a 4.1 Angstrom resolution EM map. The resulting structure exceeds current standards of NMR and EM structure determination in terms of molecular weight and precision. Importantly, the approach is successful even in cases where only medium-resolution (up to 8 Angstrom) cryo-EM data are available, thus paving avenues for the structure determination of challenging biological assemblies.

Structural Analysis of Proteins on Lipid Substrates

2000 ◽  
Vol 6 (S2) ◽  
pp. 1182-1183
Author(s):  
Elizabeth M. Wilson-Kubalek
Keyword(s):  
Structural Information ◽  
Rapid Determination ◽  
3D Structure ◽  
Three Dimensional ◽  
Molecular Complexes ◽  
Structural Data ◽  
X Ray Crystallography ◽  
Helical Protein ◽  
3D Structure Determination

Electron microscopy (EM) has become an increasingly powerful method for the determination of three-dimensional (3D) structures of proteins and macromolecular complexes. EM offers advantages over X-ray crystallography and NMR for obtaining structural information about proteins in physiological conditions, as components of large assemblies, that cannot be obtained in large quantity, or that fail to yield 3D crystals. EM has been used to obtain structural data from images of isolated molecules and molecular complexes, two-dimensional (2D) protein crystals, and helical protein arrays. Helically arranged proteins allow the most rapid determination of 3D maps because they contain a complete range of equally spaced molecular views, therefore no tilting of the sample with respect to the electron beam is required. However, so far 3D structure determination of helical assemblies has been limited to proteins that naturally adopt this organization and to proteins that fortuitously crystallize as helices.

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