This is the seventeenth of a series of symposia devoted to talks by students about their biochemical engineering research. The first, third, fifth, ninth, twelfth, and sixteenth were at Kansas State University, the second and fourth were at the University of Nebraska-Lincoln, the sixth was in Kansas City and was hosted by Iowa State University, the seventh, tenth, thirteenth, and seventeenth were at Iowa State University, the eighth and fourteenth were at the University of Missouri–Columbia, and the eleventh and fifteenth were at Colorado State University. Next year's symposium will be at the University of Colorado. Symposium proceedings are edited by faculty of the host institution. Because final publication usually takes place elsewhere, papers here are brief, and often cover work in progress.

Contents
The Effect of Polymer Dosage Conditions on the Properties of ProteinPolyelectrolyte Precipitates, K. H. Clark and C. E. Glatz, Iowa State University

An Immobilized Enzyme Reactor/Separator for the Hydrolysis of Casein by Subtilisin Carlsberg, A. J. Bream, R. A. Yoshisato, and G. R. Carmichael, University of Iowa

Cell Density Measurements in Hollow Fiber Bioreactors, Thomas Blute, Colorado State University

The Hydrodynamics in an Air-Lift Reactor, Peter Sohn, George Y. Preckshot, and Rakesh K. Bajpai, University of Missouri–Columbia

Local Liquid Velocity Measurements in a Split Cylinder Airlift Column, G. Travis Jones, Kansas State University

Fluidized Bed Solid Substrate Trichoderma reesei Fermentation, S. Adisasmito, H. N. Karim, and R. P. Tengerdy, Colorado State University

The Effect of 2,4-D Concentration on the Growth of Streptanthus tortuosis Cells in Shake Flask and Air-Lift Permenter Culture, I. C. Kong, R. D. Sjolund, and R. A. Yoshisato, University of Iowa

Protein Engineering of Aspergillus niger Glucoamylase, Michael R. Sierks, Iowa State University

Structured Kinetic Modeling of Hybidoma Growth and Monoclonal Antibody Production in Suspension Cultures, Brian C. Batt and Dhinakar S. Kampala, University of Colorado

Modelling and Control of a Zymomonas mobilis Fermentation, John F. Kramer, M. N. Karim, and J. Linden, Colorado State University

Modeling of Brettanomyces clausenii Fermentation on Mixtures of Glucose and Cellobiose, Max T. Bynum and Dhinakar S. Kampala, University of Colorado, Karel Grohmann and Charles E. Yyman, Solar Energy Research Institute

Master Equation Modeling and Monte Carlo Simulation of Predator-Prey Interactions, R. 0. Fox, Y. Y. Huang, and L. T. Fan, Kansas State University

Kinetics and Equilibria of Condensation Reactions Between Two Different Monosaccharides Catalyzed by Aspergillus niger Glucoamylase, Sabine Pestlin, Iowa State University

Biodegradation of Metalworking Fluids, S. M. Lee, Ayush Gupta, L. E. Erickson, and L. T. Fan, Kansas State University

Redox Potential, Toxicity and Oscillations in Solvent Fermentations, Kim Joong, Rakesh Bajpai, and Eugene L. Iannotti, University of Missouri–Columbia

Using Structured Kinetic Models for Analyzing Instability in Recombinant Bacterial Cultures, William E. Bentley and Dhinakar S. Kompala, University of Colorado

The symposium reported here was the thirteenth of a series devoted to talks by students on their biochemical engineering research. The first, third, fifth, ninth, and twelfth were at Kansas State University, the second and fourth were at the University of Nebraska–Lincoln, the sixth was in Kansas City and was hosted by Iowa State University, the seventh and tenth were at Iowa State, and the eighth and eleventh were at the University of Missouri–Columbia and Colorado State University, respectively. All symposia have been followed by proceedings edited by faculty of the host institution. Because final publication usually takes place elsewhere, papers here are brief, and often cover research in progress.

Content
Sequential Utilization of Mixed Sugars by Clostridium acetobutylicum, B. Hong, N. H. Choi, and L. T. Fan, Kansas State University

The Effects of Dilution Rate on the Kinetics. of Anaerobic Acidogenesis, C. J. Huang, Colorado State University

Ethanol Production by Zymomonas mobilis in Anaerobic Glucose-Limited Culture: A Yield Study, Mehmet D. Oner, Kansas State University

Hydrolysis of Cellulosics by Enterobacteria, Michael R. Sierks, Iowa State University

The Cellulase System of Chaetomium cellulolyticum, Nikhil Mehta, Colorado State University

DNA Measurement as a Tool for Estimating Biomass Concentration in the Presence of Interfering Solids, Bamidele 0. Solomon, Kansas State University

The Effect of Cellulose Crystallinity on Enzymatic Hydrolysis, Maria S. Bertran, Colorado State University

High Performance Liquid Chromatography of Di- and Trisaccharides, Michael M. Meagher, Iowa State University

Dynamics of Bubble Size .Distributions in Air-Lift Fermentors, c. H. Lee and Snehal A. Patel, Kansas State University

A Thermal Coagulation Study of Alfalfa Leaf Proteins by Differential Scanning Calorimeter, Khalif Ahmed and Bruce Dale, Colorado State University

Thermodynamic Efficiency of Photoautotrophic Growth, Hyeon Y. Lee, Kansas State University

This symposium is the sixth of an annual series conducted so that results of biochemical engineering research can be exchanged by the researchers who actually carry it out. The first four meetings were held alternately at Kansas State University and the University of Nebraska–Lincoln for attendees from those two schools. The fifth and sixth involved participants from Kansas State University and Iowa State University; this was the first meeting away from a university campus.

Contents
"Mathematical Model of Oxygen Transfer in Airlift Fermentors," Chester S. Ho, Kansas State University

"Effect of Column Height on Oxygen Transfer in Airlift Systems," Mark E. Orazem, Kansas State University

"Mixing Studies in an Oil-Water Airlift System with Motionless 15 Mixers", J. R. Gutierrez, Kansas State University

"Purification and Properties of (3-Xylosidase," Gbekeloluwa B. Oguntimein, Iowa State University

"Immobilization of Invertase to Cellulose with Cyanuric Chloride," William J. Smith, Iowa State University

"Purification and Properties of Dextransucrase," Yah Eric Chen and Hossein Kaboli, Iowa State University

"Properties of Immobilized (3-Amylase," Clarence C. Ron, Iowa State University

Eleven bacterial and two yeast strains, four of which were previously identified as having activity on a lightly cross-linked carboxymethyl cellulose (CLD-2) found in one type of superabsorbent tampon, were grown on a variety of substrates, most containing cellulosics. None produced detectable amounts of cellulases, but all elaborated beta-glucosidase. None of these 13 strains nor 3 commercially obtained beta-glucosidase preparations could hydrolyze CLD-2, although a commercial cellulase and two other bacterial preparations known to produce cellulases could. Based on these results, it appears that previous work suggesting that the degradation of CLD-2 by vaginal microbes and beta-glucosidase is implicated in the production by Staphylococcus aureus of toxin causing toxic shock syndrome must be reevaluated.

This the tenth in a series of symposia devoted to talks by students on their biochemical engineering research. The first, third, fifth, and ninth were at Kansas State University in Manhattan, the second and fourth were at the University of Nebraska–Lincoln, the sixth was in Kansas City in conjunction with the 81st American Institute of Chemical Engineers National Meeting, the seventh was at Iowa State University in Ames, and the eighth was held at the University of Missouri–Columbia.

Contents
"Combined Autohydrolysis-Organosolv Pretreatment of Lignocellulosic Materials," Robert A. Lewis, Colorado State University

"An Investigation of Cellulase Activity Assays," Minhhuong Nguyen, University of Missouri–Columbia

"Action Pattern of a Xylobiohydrolase from Aspergillus niger," Mary M. Frederick, Iowa State University

"Estimation of Heats of Combustion of Biomass from Elemental Analysis Using Available Electron Concepts," Snehal A. Patel, Kansas State University

"Design of a Wheat Straw to Ethanol Conversion Facility," Michael M. Meagher, Colorado State University

"Effects of Salt, Heat, and Physical Form on the Fermentation of Bananas," Carl Drewel, University of Missouri–Columbia

"Gas Hold-up in the Downflow Section of a Split Cylinder Airlift Column," Vasanti Deshpande, Kansas State University

"Measurement of Michaelis Constants for Soluble and Immobilized Glucoamylase," Robert A. Lesch, Iowa State University

"Kinetics of Alkaline Oxidation and Degradation of Sugars," Alfred R. Fratzke, Iowa State University

"Stability of Cereal Protein During Microbial Growth on Grain Dust," Bamidele O. Solomon, Kansas State University

The symposium whose papers are abstracted here was the fourth in a series held alternately at Kansas State University and the University of Nebraska–Lincoln. Requests for further information on projects conducted at Kansas State should be directed to Professor L.E. Erickson and on those at Nebraska to the editor.

Contents
John C. Heydweiller, "Estimating Sedimentation of Organisms in a Tower-Type Activated Sludge System"

Raymond C. Eliason, "Properties and Utilization of Small Particulates in Cattle Manure"

Kenneth H. Hsu, "Oxygen Transfer in Tower Systems with Motionless Mixers"

Raymond C. Eliason, "Hydrolysis of Sucrose by 20 Invertase Immobilized on Hollow Fibers"

Robert Shipman, "Single Cell Protein from Photosynthetic 26 Bacteria"

Peter J. Reilly, "Stability of Commensalistic Systems"

Dried and ensiled corn were each steeped with aqueous SO2 or water at initial pHs of 4-5; both were also steeped with aqueous SO2 at pH7. Initial steepwater composition or pH had less effect on yields of individual fractions and recoveries of various components than did differences between dried or ensiled corn. Recovery of starch after milling was appreciably higher with ensiled corn. Protein recovery in gluten decreased, but this was partially counterbalanced by increased protein content of the steepwater from ensiled corn. Results using batchwise steeping or a simulated countercurrent procedure were similar, though the latter gave higher starch recoveries.

This is the seventh in a series of symposia devoted to talks by students on their biochemical engineering research. The first four meetings were held alternately at Kansas State University and the University of Nebraska–Lincoln, with participants from those two schools. The next two took place at Kansas State and then in conjunction with the 8lst American Institute of Chemical Engineers National Meeting in Kansas City, with attendees from Kansas State and Iowa State Universities. This meeting, at Iowa State, was the first to include participation from the University of Missouri–Columbia.

Contents
"Properties of Soluble and In:anoblized Dextransucrase," Hossein Kaboli and Yah Eric Chen, Iowa State University

"Growth of Lipid-Producing Organisms on Formic and Acetic Acid-Containing Waste Waters," Lin-Chang Chiang, University of Missouri–Columbia

"Design of an Automated Alkaline Copper Reducing Sugar Assay," Alfred R. Fratzke and James R. Frederick, Iowa State University

"Determination of Oxygen Transfer Coefficients in Hydrocarbon Fermentations Using a Material Balance Method," Sarafin N. Sanchez and J. R. Gutierrez, Kansas State University

"Oxygen Transfer Characteristics in One Stage and Two Stage Air-Lift Towers," Mark E. Orazem, Kansas State University

"A Comparison of Biological Digestibility Tests for Cellulose," Dou-Houng Hwang, University of Missouri–Columbia

"Mechanism of Enzymatic Hydrolysis of Cellulose," L. T. Fan, Yong-Hyun Lee, and Liang-Shih Fan, Kansas State University

"Purification of Xylan-Hydrolyzing Enzymes," James R. Frederick, Alfred R. Fratzke, and Mary M. Frederick, Iowa State University

"Cellulase Production from Bagasse and Pith," A. Ferrer, Y. Alroy, and I. Brito, Kansas State University

This booklet contains abstracts of papers presented at a biochemical engineering symposium conducted at the University of Nebraska-Lincoln on April 29, 1972. This was the second annual symposium on this subject, the first having been held at Kansas State University on June 4, 1971. It is expected that future symposia will alternate between the two campuses.

Contents
S.H. Lin, Kansas State University, "Enzyme Reaction in a Tubular Reactor with Laminar Flow"

Gregory C. Martin, University of Nebraska, "Estimation of Parameters in Population Models for Schizosaccharomyces pombe from Chemostat Data"

Jaiprakash S. Shastry and Prakash N. Mishra, Kansas State University, "Immobilized Enzymes: Analysis of Ultrafiltration Reactors"

Mark D. Young, University of Nebraska, "Modelling Unsteady-State Two-Species Data Using Ramkrishna's Staling Model"

G.C.Y. Chu, Kansas State University, "Optimization of Step Aeration Waste Treatment Systems Using EVOP"

Shinji Goto, University of Nebraska, "Growth of the Blue-Green Alga Microcytis aeruginosa under Defined Conditions"

Prakash N. Mishra and Thomas M.C. Kuo, Kansas State University, "Digital Computer Simulation of the Activated Sludge System: Effect of Primary Clarifier on System Performance"

Mark D. Young, University of Nebraska, "Aerobic Fermentation of Paunch Liquor"