Karen McDonald
Professor
Assoc. Dean, College of Engineering
Department of Chemical Engineering and Material Science
3008 Bainer Hall
1037 Kemper Hall
kamcdonald@ucdavis.edu
(530) 752-8314 office
(530) 754-9452 lab
Education
B.S., Stanford University, 1979
M.S., University of California, Berkeley, 1980
Ph.D., University of Maryland, College Park, 1985
Research Interests
Plant Cell Culture Bioprocessing
Profs. Karen McDonald and Alan Jackman are investigating the production of pharmacologically important proteins from plant cell cultures. The research group is studying plant cell cultures of Trichosanthes kirilowii, a member of the Cucurbitaceae family found in China, Japan and Korea. This plant is of particular interest since it is a source of proteins known as ribosome inactivating proteins (RIPs) which have a variety of potentially useful pharmaceutical activities such as antiviral, antitumor, antidiabetic, abortifacient and immunomodulatory. One of these proteins, a 27 kDa protein isolated from the root tuber was found to selectively inhibit viral replication in human blood cells infected with HIV-1. This protein, known as trichosanthin has completed Phase II clinical trials as an AIDS drug. More recently, a 29kDa protein referred to as TAP-29 was isolated from root tubers of T. kirilowii and was also found to have anti-HIV activity although the cell toxicity was lower for this compound. The research group is investigating the kinetics of growth, quantification and characterization of intracellular and extracellular proteins from plant cell cultures and the influences of important bioreactor variables on RIP productivity using natural and genetically transformed T. kirilowii cell lines. The ultimate goal of the research is the determination of optimal bioreactor operating strategies to maximize production of functional proteins from these cultures and to characterize new potential therapeutic proteins.
Photobioreactor Production of Sulfolipids
A wide variety of industrially important compounds are found naturally in photosynthetic organisms and are associated with photosynthetic membranes and/or organelles. We are studying the production of sulfolipids, important due to their anti-tumor and anti-HIV properties, in cyanobacterial cultures in photobioreactors. Production of sulfolipids in cyanobacteria is known to be closely tied to the formation of photosynthetic membranes, which in turn is stimulated under conditions of low light and low nitrogen levels.
At high cell densities, however, growth rates of photosynthetic organisms are typically low and limited by light. Thus, optimization of photobioreactor systems for the production of photosynthetic membrane-associated compounds provides a significant engineering challenge to obtain high cell densities in short time periods with high product levels. Profs. McDonald and Jackman are collaborating with other faculty on campus to characterize, quantify, model and optimize the production and product recovery of sulfolipids from cynanobacterial cultures. The overall goals of this research program are to combine biological and bioprocessing approaches to maximize the production of high value, photosynthetically-related compounds (sulfolipids) from cyanobacterial cultures.
On-Line Process Diagnosis Methods
A major objective of the chemical/petrochemical process industries is to achieve incident free operation. Currently, abnormal process situations often go undetected by plant operators/personnel until alarms are triggered.
Profs. Karen McDonald and Ahmet Palazoglu are working on the development of general techniques for detecting trends in process data and classifying these trends. To facilitate data compression while preserving the main features of the data, they are using wavelet decomposition followed by symbolic representation using fuzzy triangular episodes. Hidden Markov models are used to classify these trends as normal, abnormal or uncertain. The goal of the work is to develop automated methods to detect abnormal process situations as they arise and notify plant operators at the pre-alarm stage.
