Biological Engineering: a Newdiscipline for the Next Century

Biological Engineering: A NewDiscipline for the Next Century

Bernard Y. Tao*

ABSTRACT BIOTECHNOLOGY:FRIEND OR FOE’,? Increasingawareness and concern about living systemsand The wordbiotechnology stirs a mixture of uncertain the useof biologicaltechnology has led to demandfor individu- emotionsin most people (Davis, 1991). Visions of medi- als withan understandingof the life sciencescombined with engineeringskills. Importantsocial/economic issues involving cal miracles coexist with unsettling fears about rampant environmentalquality, the use of recombinantgenetics in killer microbes, genetically altered foods, and bionic/ foods/pharmaceuticals,andthe qualityof life havecreated a cyborg"robocops." This dichotomyexists because of the thrivingjob marketfor individualswho understand the eco- fundamentalbelief that living systemsshould not be tech- nomics,science, and technology of dealingwith living systems nological products. Technologyis perceived as a means andtheir products.A new discipline, Biological Engineering, to alter or transform the environment to meet human has evolvedin responseto this growingneed for technological- needs. Engineers synthesize plastics, build magnetic ly trainedindividuals with backgrounds in the life sciences.This trains, and create digital televisions. Peoplecontrol tech- articlereviews the issues driving the need for biological engineer- nology. But whenit comesto transformingliving systems ing disciplineand summarizes current curricula at severaluniver- into controlled, engineeredcommodities, there is a funda- sities. ThePurdue Biochemical and Food Process Engineering mentalresistance. Life is perceivedas a creative, unre- programis presentedas a modelfor the implementationof these strained, independentprocess. Biotechnologychallenges curriculumobjectives. this perception with its capacity to manipulatethe bio- chemicalmolecules that create and sustain life. Thereali- zation that living systemscan be technologicallycreated and synthetically manipulated, no different from the steel, plastic, and glass that are usedand discardedevery HE INDUSTRIALREVOLUTION of the 1800s changed day, causes fear and uncertainty (Mitcham,1989; Nais- T forever the waysin whichour civilization interacts bitt and Aburdene,1990). However,biotechnology is also with nature. Originally an agrarian society dependenton capable of yielding remarkablebenefits. Currenttechnol- animal labor, science and engineering has supplanted ogy is creating transgenic plants to producenew food and animal work with chemical energy, allowing dispersed industrial products from existing high-yield crops populations to condenseinto large cities. Usingphysi- (Gordon-Kammet al., 1990; Kessler et al., 1992; Moshy, cal/chemical engineering principles, natural materials 1986). Hostsof newpharmaceuticals from rare plants and were transformed into a host of newproducts that have animals are being developed (Gibbons, 1992; Moffat, dramatically changedsociety, such as automobiles, air- 1992). Transgenic domestic animals are nowbeing used planes, refrigerators, plastics, and television. as bioreactors to produce newpharmaceutical proteins Today,we are again at the forefront of a newengineer- in their milk (Moffat, 1991;Glanz, 1992). Extinct or en- ing revolution in biotechnologythat promisesto funda- dangered species are being preserved using domestic mentally changethe waywe live. Duringthe Industrial animals as universal surrogate mothers (Anonymous, Revolution, we learned howto alter our environment, 1989). Completemapping of the humangenome promises using machinesand natural resources. Duringthe upcom- to radically alter our abilities in medicaldiagnostics, ing Biotechnological Revolution, we will learn howto forensics, and treatment (Jordan, 1992). Genetherapy, alter living systemsand their componentsto suit the en- the use of recombinantgenetic cells and viruses to treat vironment and satisfy humanneeds/desires. However, diseases, promisesto overcomeinherited disorders such the raw materials that fuel the BiotechnologicalRevolu- as diabetes, sickle cell anemia,and cystic fibrosis, as well tion will not be steel, coal, or plastic. Theywill be DNA, as nongeneticdiseases such as AIDS,cancer, and leuke- proteins, and other biomaterials derived frommicrobes, mia (Anderson, 1992; Collins, 1992; Kolberg, 1992; plants, animals, and humans.To paraphrase the cartoon Rosenfeldet al., 1992).Bacteriorhodopsin, the light sens- character Pogo, "Wehave found newraw materials, and ing protein in eyes, is being incorporatedinto photoelec- they are us." This article highlights efforts to redefine tric receptorsfor ultrafast optical sensorsused in optical engineeringcurricula to embracethe life sciences and de- computers(Miasaka et al., 1991). Several researchers are velop an appreciation for the uniquenature of the engi- isolating DNAfrom bacteria that grow in hydrothermal neering issues involvedwith these disciplines. underseasvents to clone newhigh temperature-stableen- zymes for use in starch depolymerization, frustose production, coal desulfurization, bioremediation, and Biochemicaland Food Process Engineering Program, Dep. of Agricul- gold extraction (Gibbons, 1991). tural Engineering,Purdue Univ., W. Lafayette, IN 47907. Received 19 Aug.1992. *Corresponding author. Withinthe next 50 yr, wewill see incredible advances in biological engineering,comparable to the physical and Publishedin J. Nat.Resour. Life Sci. Educ.22:34-38 (1993).

34¯ J. Nat.Resour. Life Sci. Educ.,Vol. 22, no.1, 1993 chemical engineering advances of the past century. Un- new molecular biological tools, engineering applications doubtedly, visionaries in the 1890s anticipated antibiot- are also springing up in agriculture, medicine, ecology, ics, automobiles, consumer electrical power, radio, and environmental studies. With new discoveries com- airplanes, and refrigerators. But whocould have antici- ing almost daily, coherent engineering programs are pated space-age plastics, personal computers, color tele- neededto teach the scientific principles, engineeringtech- vision, bullet trains, microwave ovens, and VCRs? nology, ethical use of these developments, and their Similarly, consider the environmental and social effects potential effects on society. of these technologies. The engineers who designed air Historically, the curricula of agricultural and chemi- conditioners and refrigerators never dreamedthat chloro- cal engineering have added elective courses in biochemi- fluorocarbons could deplete the ozone layer. Automo- cal or biosystems engineering to meet this need. bile and power plant engineers didn’t anticipate global Trend-setting engineering schools, such as MIT, nowre- warmingdue to increased carbon dioxide emissions. The quire all students to take biology courses as a fundamental designers of television probably never anticipated that science, similar to chemistry, physics, and mathematics. Americanswould spend an average of 6 ha per day watch- However, with the expanding technology and the demand ing the TVand read less than one book per year. Just for a more comprehensive life sciences background, the as vacuum-tubeengineers in the 1920s could not have en- need for a more fundamental disciplinary change has visioned silicon microprocessors and laser optics, the ap- emerged (Johnson and Davis, 1990). plications of biotechnology in the next century will probably exceed our wildest dreams. Unimagined suc- Core Biological Engineering Curriculum cesses and miracles may be just around the corner in Offsetting these benefits, however,are the risks of per- A set of workshops, funded by the USDA,was held manently altering both the environment and ourselves, to develop curriculum guidelines for biological engineer- due to the fundamental nature of the technology. For ex- ing (Garrett, 1992). The main emphasis of these guide- ample, the Human Genome project offers immense lines was to define clearly the concepts encompassedby promise for therapeutic treatments via targeting and al- biological engineering and the competencies expected of teration of human genetic disorders (Jordan, 1992). biological engineers. A set of core courses was developed, However, such technology also offers opportunities to composedof engineering-based topics in biology, bio- radically alter long-accepted social customs/traditions, physics, and biomaterials. Table 1 summarizes the five such as behavioral genetics or selective genetic manipu- core course topics that were defined, including brief lation of humanphysiological traits (Aldhous, 1992). descriptions of the course subjects. A more detailed dis- Social issues involving personal privacy, individual/cor- cussion can be found in Garrett (1992). This curriculum porate ownership of genetic materials, and discrimina- is intended to complement existing engineering and tion based on genotype have already arisen in the legal science curricula, based on the agricultural engineering system. As authors of technology, we bear the responsi- discipline. bility not only to develop applications of this new tech- Table 1. Suggested core courses for biological engineering educa- nology, but also to evaluate the social consequences and tion (from Garrett, 1992). inform others of the risks and benefits. Wecannot ethi- BiologyI for Engineers cally abandon these responsibilities to well-intentioned, (istyear course; prerequisites: none) ¯ Structure,function, and energy transformations of biosystems at the but technically uneducatedpoliticians and social activists. cellular,organismal, andpopulation levels affecting the solutions to As teachers, we must educate a new generation of en- engineeringproblems. gineers in both the principles of biotechnology and the InstrumentationforBiological Systems implications of biological engineering. Incorporating (2ndyear course; prerequisites: physics, math, computer programming) ¯ Fundamentalaspects of measurementsystems, emphasizing sensors these technical and ethical considerations into a coher- andtransducers used in agricultural, biological, andenvironmental ap- ent biological engineering curriculum is then the challenge plications. facing us. TransportPhenomena (3rdyear course; prerequisites: thermodynamics, fluidmechanics, engineer- ingbiology) BIOLOGICAL ENGINEERING ¯ Fluidmechanics, thermodynamics, andbiology for engineers. EngineeringProperties of Biological Materials {3rdyear course; prerequisites: physics, biology, general chemistry, differ- Newengineering disciplines have always evolved from entialequations, fluid mechanics) combinationsof existing scientific and engineering fields. ¯ Importanceof biologicalmaterials in engineeringsystems Agricultural engineering grew from agronomy and ¯ Terminologyand definitions of engineering properties of biological materials mechanical engineering. Chemical engineering evolved ¯ Interactionsbetween living and nonliving components of biological from chemistry and mechanical engineering. Biological systems engineering, a new discipline, is now coalescing from BiologyII forEngineers (3rdyear course; prerequisites: physics, thermodynamics, engineering biology/biochemistry, food science, agricultural engineer- biology,transport phenomena~ ing, and chemical engineering (Cuello, 1992). ¯ Interactionsof biological organisms and their thermal, aerial, elec- Conceptually, biological engineering is the technical tromagnetic,and chemical environments. utilization of living systems, their components, and Modelingof Biological Systems {4th year course; prerequisites: computerprogramming, differential equa- products to fulfill social needs. Current biological en- tions, transport phenomena,engineering biology) gineering applications focus on the food processing and ¯ Computersimulation as a tool for understanding, designing, and test- pharmaceutical industries. However,with the advent of ing biological systems

J. Nat. Resour. Life Sci. Educ., Vol. 22, no. 1, 1993 * 35 To gauge the availability of courses meeting these cal engineering, listed by subject area. Amongthe univer- descriptions, a recent ASAEsurvey of 35 North Ameri- sities surveyed, those providing multiple biological can universities reviewed existing biological engineering engineering courses and/or degrees in biological engineer- curricula. A directory of these courses, including brief ing are Arkansas, University of British Columbia course descriptions, Accreditation Board for Engineer- (Canada), Cornell, Clemson, University of California- ing and Technology (ABET)credits, and instructor con- Davis, Florida State, University of Guelph (Canada), tacts, is available (ASAE, 1992). Table 2 provides Kentucky, University of Manitoba (Canada), Michigan breakdownof the number of courses related to biologi- State, Mississippi State, Nebraska, North Carolina State, Penn State, Purdue, and Texas A&M. Table 2. Available core biological engineering courses (from ASAE, 1992). Purdue’s BFPE Program Numberof courses Subject area currently taught As an example of a successful biological engineering Biology for engineers 20 program, the curriculum and objectives of Purdue’s Bio- Engineeringproperties of biological materials 26 Processing of biological materials flood} 33 chemical and Food Process Engineering (BFPE) Program Analysis and modeling of biological systems 25 are presented (Tables 3 and 4). In its 12-yr history, the Bioinstrumentation 11 Purdue BFPEprogram has graduated more than 100 stu- Biological and biochemical engineering 33 Biological waste management 9 dents, both undergraduate and graduate. It has a current Design of biological systems 5 enrollment of approximately 60 undergraduate students Energy of biological systems 5 (soph./jr./sr.) and is an ABET-approvedengineering

Table 3. Purdue food process engineering curriculum. Credit hours required for graduation: 130 {Coursecredit hours in parentheses} First semester Fourth semester Seventh semester (1} ENGR100 Engineering Lectures {3} AGEN210 Biol. Material]Energy Balances (D AGEN490 Prof. Practice (4} CHM115 General Chem. (4} CHM257 Organic Chemistry (3} FS 462 Food Microbiology {3} CS 150 Prog. Eng. and Sci. (3} CE 273 Mechanics of Materials (3} AGEN555 Bio./Food Proc. Eng. Unit Ops. {3} ENG101 English Composition I (4} MA262 Lin. Alg./Diff. Eqn (3} CHE456 Proc. Dynamics and Control (5} MA161 Plane Geometry/Calculus I {3} HUMANITIES ELECTIVE 13) ELECTIVE Second semester Fifth semester (3} HUMANITIES ELECTIVE (4} CHM116 General Chemistry {3} AGEN305 Phys. Prop. Biol. Mat. Eighth semester (3} COM114 Fund. of Speech Comm. (4} FS 453 Food Chemistry (4) AGEN556 Bio./Food Plant Design ~5} MA162 Plane Geometry/Calculus II 13} CHE211 Chem. Eng. Thermo. 16) ELECTIVE {4} PHYS152 Mechanics (3} CHE377 MomentumTransfer (6) HUMANITIES ELECTIVE Third semester (3} HUMANITIESELECTIVE (3} AGEN205 Ag. Eng. Computations Sixth semester (4} BIOL225 Biology {3) CHE348 Chem. Rxn. (41 MA261 Multivariate Calculus i3} CHE378 Heat and Mass Transfer 13} ME270 Basic Mechanics I (4} BIOL221 Microbiology {3} PHYS241 Electricity and Optics ~3} AGEN554 Food Proc. Eng. Lab. (3} HUMANITIESELECTIVE

Table 4. Purdue dual degree biochemical and food process engineering curriculum. Credit hours required for graduation: 158 (Course credit hours in parentheses) First semester Fifth semester Eighth semester (1} ENGR100 Freshman Eng. Lectures (3) AGEN305 Phys. Prop. Biol. Mat. (3) AGEN580 Proc. Eng. Renew. Resources (4} CHM115 General Chemistry (3) CHE377 MomentumTransfer (3} AGEN554 Food Proc. Eng. Lab. (3~ CS 150 Prog. Eng. Sci. (3} CHE211 Chem. Eng. Thermo. (2) BCHM322 Analytical Biochem. {3} ENG101 English Composition 1 (3) CHM261 Organic Chemistry (3) BCHM562 General Biochem. II (5} MA161 Plane Geometry/Calculus I (1) CHM263 Organic Chem. Lab. (5} CHM372 Physical Chemistry Second semester (3) HUMANITIES ELECTIVE Ninth semester ~4} CHM116 General Chemistry Sixth semester (1) AGEN490 Prof. Practice (3} COM114 Fund. Speech Comm. (3) CHE378 Heat/Mass Transfer (2) BIOL439 Lab. General Microbiology {5} MA162 Plane Geometry/Calculus II (31 CHE348 Chem. Rxn. Eng. (3} AGEN555 Bio./Food Proc. Eng. Unit Ops (4} PHYS152 Mechanics (3) CHM262 Organic Chemistry (2) BIOL438 General Microbiology Organic Chem. Lab. (3) HUMANITIES ELECTIVE Third semester (1) CHM264 {3} AGEN205 Ag. Eng. Computations {2} BCHM221 Analytical Biochem. (3~ ELECTIVE (4} BIOL225 Biology (3) HUMANITIES ELECTIVE Tenth semester (4} MA261 Multivariate Calculus Seventh semester (4) AGEN556 Bio./Food Plant Design (3~ ME270 Basic Mechanics I (3) CHE456 Process Dynamics and Control (21 BCHM572 Adv. Biochem. Techniques (3} PHYS241 Electricity and Optics (1) BCHM221LLab. Anal. Biochem. (2) BCHM565 Biochem. Life Processes Fourth semester (3} BCHM561 General Biochemistry (3~ HUMANITIESELECTIVE (3} AGEN210 Biol. Material]Energy Balances {3} AGRY320 Genetics (3) ELECTIVE (4} BIOL226 Biology I1) AGRY320L Genetics Laboratory (3} CE 273 Mechanics of Materials (3) CHE597T Biochemical Engineering (4} MA262 Linear Algebra/Diff. Equations ~3) HUMANITIES ELECTIVE {3~ HUMANITIES ELECTIVE

36 ¯ J. Nat. Resour. Life Sci. Educ., Vol. 22, no. 1, 1993 program. The curriculum includes introductory courses nologies, and environmental concerns. Both options have and advanced courses in biology, food science, biomateri- CO-OP opportunities available to provide industrial ex- al physical properties, and biochemistry. Engineering periences and improved understanding of career oppor- components include introductory courses in biological en- tunities. Such a well-integrated, interdisciplinary program gineering, intermediate engineering courses taught is a good model for developing biological engineers. The through the chemical and mechanical engineering depart- availability of options in current technologies (food ments, and engineering design courses in food and bio- processing), CO-OP programs, and dual-degree biochem- logical process engineering in the senior year. Electives ical engineering provide an evolving educational curric- are offered to enhance the individual student's profes- ulum that is adaptable to new growth and provides future sional capabilities and must be selected from the list of leaders to meet growing employment demands and so- courses approved by the faculty of the Agricultural En- cial needs. gineering Department. Another challenge arises in the area of ethics and com- In recognition of the diverse industrial nature of the munication skills. Due to the inherent public anxiety biological engineering discipline, several options are avail- caused by the potential of this technology, biological enable to suit the needs of students and industrial employ- gineers will be held to a very high standard of profes- ers. The 4-yr program focuses on food process sional ethics and social responsibility. They must be able engineering and provides an excellent engineering talent to explain clearly the benefits and risks of the use of this for the food industry. The BFPE degree option is a dual technology and must continually promote a higher level degree, 5-yr program, culminating in B.S. degrees in en- of public understanding. Therefore, this discipline should gineering and biochemistry. It focuses on students in- also include requirements for classes in ethics, writing, terested in the pharmaceutical and biochemical industries. and public speaking. To a large extent, existing social Listings of the curricula for each program are presented sciences/fine arts curricula can fulfill these requirements. in Tables 3 and 4. Individually tailored academic- New biological engineering courses should include dis- industrial cooperative programs (CO-OP) are also cussions and assignments focusing on both the social and available. ethical effects of engineering choices as well as the technical aspects of the craft. Senior capstone design courses SUMMARY must include assessments of social and environmental issues, as well as economic and technical concerns. The The concept of biological engineering as a discipline education of biological engineers must include careful is an idea whose time has come (Johnson and Davis, training to understand and anticipate public concerns 1990). The expoential rate of new discoveries in the bio- about their technologies and to develop positive, respon- logical sciences has created a demand for the develop- sible, ethical approaches to listening and acting ac- ment of engineering technology to apply these discoveries cordingly. to fulfill social needs. Although existing engineering curricula can be modified by the addition of peripheral bio- logically oriented courses, the highly interdisciplinary nature and extent of the topics require a more comprehensive, disciplinary focus. One of the challenges facing this new discipline is curriculum development. How can the essential new scientific information be combined with existing core engineering subjects? In the present case, this involves combining courses in biology, biophysics, biochemistry, food science, and microbiology with existing engineering requirements. Superimposing these requirements on the existing criteria for agricultural, mechanical, or chemical engineering requires careful analysis of course con- tent. Existing courses can then be reoriented to emphasize new topical information, relinquishing some courses, and adding new courses. The suggested core curriculum for biological engineering (Table 1) provides a model set of criteria. The Purdue BFPE curricula provide examples of how existing interdisciplinary courses can be combined into a cohesive set of options, complemented by introductory and capstone engineering courses. These curricula enable students to tailor their education to meet their individual interests and career goals. The 4-yr program focuses on serving the immediate industrial need for biological engineers in the food processing industry. The 5-yr program provides unique biochemically oriented biological engineers for developing industries, such as those involved with pharmaceuticals, recombinant genetic tech-

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