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Amino Acid Utilization by Activated Sludge DALE A, CARLSON, Associate Professor of Civil Engineering University of Washington Seattle, Washington and L. B. POLKOWSKI, Professor of Sanitary Engineering State University of Iowa Iowa City, Iowa Proteins, lipids and carbohydrates constitute the major organic fractions of domestic sewage. Each of these classes encompasses a variety of compounds. The diversity in chemical complexity and structure in each class makes strict classification of these compounds difficult. The proteins, for example, are subdivided by such criteria as solubility, gross structure, state of degradation or the content of nonprotein constituents. The primary characteristic of the proteins is, however, that they yield amino acids when hydrolyzed. PENETRATION OF CELL BOUNDARIES The utilization of the proteins and their constituent amino acids, as well as of the lipids and carbohydrates, is accomplished principally by the bacteria as a means of nutrition. These compounds must be able to enter into the bacterial cell and they must be usable in the cell's metabolic pathways. The uses of a given compound by a bacterial cell depend on the enzymes the cell possesses (1). The modes of entrance of compounds into the cytoplasm of the bacterial cell is illustrated in the following figures. Cellular boundaries are shown in Figure 1 on a simplified sketch of a typical bacillus. The interior cytoplasm of this cell is bounded first by a membrance, or sac. Bacterial form is maintained by the rigid cell wall on the exterior of this membrane. Surrounding the whole organism is the slime layer or capsule which varies in thickness from being barely visible with the electron microscope to being larger than the cell itself. Nutrient material approaching this bacterial cell would first encounter a degree of orientation in the sunounding medium which restricts the movement of ionized particles. Progressing further the moving material encounters waste products of the bacterial cell and then moves into the denser jelly of the capsule. The next obstacle encountered by the nutrient particle is the cell wall which might be described as a veritable brush pile of rigid girders. Besides this microfibrillar structure, many cell walls appear to be, in electron micrographs, a lattice of spherical particles in hexagonal or square packing. Some bacteria, such as the Escherichia coli, apparently have a multilayered wall. Like a sieve, the cell wall apparently can offer some resistance to the entrance of particulate matter on the basis of particle size. The site of the differential permeability exhibited by bacterial cells is primarily the cell membrane. Several theories have been proposed to explain the selective entrance of particles through the cell membrane to the interior of - 77 -
Object Description
Purdue Identification Number | ETRIWC196208 |
Title | Amino acid utilization by activated sludge |
Author |
Carlson, Dale A. Polkowski, Lawrence Benjamin, 1929- |
Date of Original | 1962 |
Conference Title | Proceedings of the seventeenth Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/cdm4/document.php?CISOROOT=/engext&CISOPTR=9369&REC=10 |
Extent of Original | p. 77-94 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-05-18 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 77 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Amino Acid Utilization by Activated Sludge DALE A, CARLSON, Associate Professor of Civil Engineering University of Washington Seattle, Washington and L. B. POLKOWSKI, Professor of Sanitary Engineering State University of Iowa Iowa City, Iowa Proteins, lipids and carbohydrates constitute the major organic fractions of domestic sewage. Each of these classes encompasses a variety of compounds. The diversity in chemical complexity and structure in each class makes strict classification of these compounds difficult. The proteins, for example, are subdivided by such criteria as solubility, gross structure, state of degradation or the content of nonprotein constituents. The primary characteristic of the proteins is, however, that they yield amino acids when hydrolyzed. PENETRATION OF CELL BOUNDARIES The utilization of the proteins and their constituent amino acids, as well as of the lipids and carbohydrates, is accomplished principally by the bacteria as a means of nutrition. These compounds must be able to enter into the bacterial cell and they must be usable in the cell's metabolic pathways. The uses of a given compound by a bacterial cell depend on the enzymes the cell possesses (1). The modes of entrance of compounds into the cytoplasm of the bacterial cell is illustrated in the following figures. Cellular boundaries are shown in Figure 1 on a simplified sketch of a typical bacillus. The interior cytoplasm of this cell is bounded first by a membrance, or sac. Bacterial form is maintained by the rigid cell wall on the exterior of this membrane. Surrounding the whole organism is the slime layer or capsule which varies in thickness from being barely visible with the electron microscope to being larger than the cell itself. Nutrient material approaching this bacterial cell would first encounter a degree of orientation in the sunounding medium which restricts the movement of ionized particles. Progressing further the moving material encounters waste products of the bacterial cell and then moves into the denser jelly of the capsule. The next obstacle encountered by the nutrient particle is the cell wall which might be described as a veritable brush pile of rigid girders. Besides this microfibrillar structure, many cell walls appear to be, in electron micrographs, a lattice of spherical particles in hexagonal or square packing. Some bacteria, such as the Escherichia coli, apparently have a multilayered wall. Like a sieve, the cell wall apparently can offer some resistance to the entrance of particulate matter on the basis of particle size. The site of the differential permeability exhibited by bacterial cells is primarily the cell membrane. Several theories have been proposed to explain the selective entrance of particles through the cell membrane to the interior of - 77 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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