Arnold Demain

Arnold L. Demain (born April 26, 1927) is an American microbiologist.^[1][2] During his 60-year career, he has gained a renowned reputation in the field of industrial microbiology. He was formerly the Professor of Industrial Microbiology in the Biology Department at MIT and Founder and Head of Department of Fermentation Microbiology at Merck & Co. The August 2010 edition of The Journal of Antibiotics celebrated his scientific career.^[3] He has been described as “one of the world’s leading industrial microbiologists” and as “a scientist constantly in the forefront of industrial microbiology and biotechnology.” He has been “a pioneer in research on the elucidation and regulation of the biosynthetic pathways leading to the penicillins and cephalosporins” and “has been instrumental in the development of the beta-lactam industry. ” One feature of Demain's work, according to Microbiology Australia, has been his “ability to undertake fundamental research on systems with clear industrial applications, recognising that biodiscovery is the start of the road that includes strain improvement to achieve levels of product synthesis that warrant further investment to take products into the marketplace.”^[4][5]

Demain has published over 500 papers, has co-edited or co-authored fourteen books, and has taken out 21 U.S. patents.^[4][5]

Early life and education

Demain was born in Brooklyn, New York, on April 26, 1927. His grandparents were all immigrants from the Austrian-Hungarian Empire. As a boy he worked delivering groceries and was also a stock boy at Lord & Taylor’s department store in Manhattan.^[6] Demain's father, Henry, was in the pickle manufacturing business, managing a canning and pickling plant for Vita Foods Corp. in Chestertown, Maryland. Demain's uncles Ben and Seymour operated another pickling factory, Demain Foods Co., in Ayden, North Carolina. According to one source, “Henry was a leader in the pickle business, working for Fields and then Bloch and Guggenheimer in New York before setting up the pickle plant in Chestertown.” Demain himself said that his grandfather, Joseph Demain, “had sold pickles for years in one of New York’s major market areas.”^[6] Demain attended five different public elementary schools and three different public high schools in Brooklyn and the Bronx, and graduated high school at age 16.^[4][6][7]

“My father convinced me that I should become a food fermentation expert,” Demain later said. “He knew only one professor, Frederick W. Fabian, who conducted annual one-week summer courses at Michigan State titled The Pickle and Kraut Packers’ School.” After his high-school graduation, then, Demain's parents “took him by train to Michigan State College (MSC) (now Michigan State University) in East Lansing,” because Fabian, “the leading investigator of cucumber fermentations in the U.S.,” taught there.^[4][6] Demain attended Michigan State briefly, then joined the U.S. Navy in 1945 and spent two years in Philadelphia caring for amputees who were members of the armed forces who had been injured in the war. Demain returned to Michigan State in 1947, earning B.S. and M.S. degrees in bacteriology from the Department of Microbiology and Public Health in 1949 and 1950 respectively. His master's research topic was the spoilage and softening of pickles during fermentation, a phenomenon that, he concluded, was probably caused by pectic enzymes.^[6][7] Demain's choice of this topic “was definitely influenced by his father’s profession,” says one source.^[6]

“During my stay at Michigan State,” Demain later said, “I worked in Fred Fabian’s lab on spoilage (softening) of pickles. In the summers, I worked for my father and my uncles. My summer responsibilities from 1947 to 1950 were to start in South Carolina, buying cucumbers from farmers and shipping them by truck to my father’s pickle factory. I followed the cucumber crop virtually state by state from South Carolina to Wisconsin. During this trip north, I also worked at my uncle’s pickle plant in North Carolina, my father’s plant in Maryland, and ran a pickling plant in Brodhead, Wisconsin. During my periods of work at my uncle’s plant, I met Professor John ('Jack') Lincoln Etchells of the US Department of Agriculture and North Carolina State University. When my uncle’s fermentations went awry, they often called on Jack to come to Ayden and recommend measures to correct the problems. Jack became my first mentor.” At MSC Demain met and married a fellow student, Joanna (“Jody”) Kaye from Youngstown, Ohio.^[6]

From MSC, Demain went to the University of California's Department of Food Science, which was first at the Berkeley campus and then at Davis. It was there that he began work on his Ph.D. project on polygalacturonase of Saccharomyces fragilis. The project resulted in four papers on pectic enzymes, one of which published in Nature.^[4] At Berkeley, he was in charge of the cultures in UC's yeast collection. Spending “four years under the tutelage of the prominent yeast scholar, Herman J. Phaff,” who became his second mentor, Demain “elucidated the mechanism of pectic acid degradation by the extracellular polygalacturonase (YPG) of the yeast Klyveromyces fragilis,” later recalling that the two men “worked from early morning until evening, went home for dinner with our spouses, and returned to the lab for research and discussions that lasted until the wee hours.”

Demain said that he and Phaff “apparently were the first in the world to carry out affinity chromatography, using a pectic acid gel to selectively adsorb YPG from culture filtrates. We proved that the entire hydrolysis of polymer to dimer was accomplished by a single enzyme in contrast to current thought that multiple enzymes were necessary. The work was published in four publications, one appearing in Nature. I didn’t realize how significant that was, but I learned later in life (after receiving many rejection notices form Nature) that for a graduate student to publish one of his/her first papers in Nature was an unusual feat.”^[6] Demain received his Ph.D. in 1954.^[7]

During his first years in Rahway, Demain “innovated methods to enhance the production of secondary metabolites using starved resting cells. He was the first to detect feedback inhibition of penicillin production by the amino acid lysine...and originated the study on the effects of primary metabolites on the secondary metabolism of microorganisms.” Demain has said that his work in Rahway “showed that over 99% of the penicillin formed appeared in the liquid portion of the broth and that penicillin was partially degraded during its production. Thus, I showed that the apparent rate of penicillin production was the net result of synthesis and inactivation during fermentation. I also confirmed a controversial claim by Koichi Kato of Japan in 1953 that he had isolated the 'penicillin nucleus' from fermentations conducted without the addition of the side chain precursor, phenylacetate.”

Career

Merck, Sharp & Dohme

In early 1954, Demain and his wife Jody moved to Danville, Pennsylvania, where he worked as a research microbiologist for Merck Sharp & Dohme, studying the synthesis of penicillin. His work helped identify the amino acids that form the nucleus of penicillin, established the mechanisms that enable primary metabolites and carbon sources to regulate secondary metabolite synthesis, and demonstrated that penicillin was the product of synthesis and inactivation during fermentation. (He would later resume his penicillin research at the Massachusetts Institute of Technology.)^[4][6] In late 1955, Demain moved on to Merck's penicillin research laboratories in Rahway, New Jersey, where he “worked on fermentation microbiology, â-lactam antibiotics, flavor nucleotides, and microbial nutrition.”^[7]

This discovery by Demain has been described as being “of great economic importance, since the nucleus was later used and is still used to produce all semisynthetic penicillins of commerce...During the first 10 years in Rahway, he and his technical assistant Joanne Newkirk made great progress on microbial growth factors, cephalosporin biosynthesis, protein synthesis, and nucleotide fermentation. His group was the first to discover that one of the growth-stimulating effects of protein digests was due to lipids associated with proteins such as casein, and not always due to their peptides or amino acid components. He demonstrated that Lactobacillus homohiochi and L. heterohiochi, contaminants of the wine making process, not only tolerated over 20% ethanol, but required ethanol for optimal growth.” Demain's superiors at Merck, David Hendlin and Boyd Woodruff, became his “third and fourth mentors.”

“My participation in Merck’s Microbiology Department,” Demain recalled, “was brought to a close in 1964 when I was asked to form a new department at Merck that would involve the improvementof product biosynthesis in microbial strains.”^[6] This request came from Merck Vice President Karl Pfister. The new department, which Demain named the Department of Fermentation Microbiology, provided him with “an opportunity to set up a new group of over 30 people dealing with improvement of current Merck fermentations and development of fermentations for new products.”^[6] Demain “directed research and development on processes for monosodium glutamate, vitamin B12, streptomycin, riboflavin, cephamycin, fosfomycin, and interferon inducers,”^[7] and “elucidated the mechanism by which the biosynthesis of cephalosporin in Cephalsporium acremonium was stimulated by the presence of methionine – a new mechanism which had not been reported before.”

Demain and his team in the Department of Fermentation Microbiology also studied “the overproduction of l-glutamic acid (GA) by Corynebacterium glutamicum, since Merck was selling monosodium glutamate (MSG) at the time.” In addition, the team managed to boost production yields of vitamin B12. “Around 1966,” Demain later said, “Max Tishler, the President of MSDRL, gave me the responsibility to develop a microbiological riboflavin (vitamin B2) process....We chose Ashbya gossypii as our organism because it was already known to make 5g/liter. By the time I left Merck in 1969, we had developed a process capable of producing 12g/liter.”^[6]

The work done under Demain's direction in Rahway has been described in Microbiology Australia as “remarkable” in its “level of innovation,” in that it identified “novel biochemical pathways” that improved “natural levels of production” several thousandfold.^[4] Demain himself has said that thanks to Merck, “I learned early in my career that there was a lot more to applied microbiology than pickles and sauerkraut, and that microbes could be used to make antibiotics, produce commercial enzymes, convert steroids to be used for arthritis and rheumatism, make amino acids and vitamins for human and animal nutrition, and make many medicinals for human and animal health.”^[6]

Massachusetts Institute of Technology

In 1968, Demain was invited by Nevin Scrimshaw, head of the Department of Nutrition and Food Science at the Massachusetts Institute of Technology,^[8] to become a full professor at that university. The next year Demain became Professor of Industrial Microbiology in Scrimshaw's department at MIT and set up a fermentation microbiology laboratory there. Demain stayed at MIT for the next 32 years, reportedly providing “an exciting working environment” for postgraduates, postdoctoral fellows, and visiting scientists. In 1970, Demain went to Prague to present the closing Plenary Session address at the first Genetics of Industrial Microorganisms Symposium. He spoke on the “marriage of genetics and industrial microbiology.”^[4]

At MIT, Demain and his team “pioneered research on the elucidation and regulation of the biosynthetic pathways leading to penicillins and cephalosporins.” They did research into “peptide antibiotics and sporulation in B. subtilis; mycotoxins; new antibiotic discovery through mutational biosynthesis (making idiotrophs); cellulases and ethanologenic clostridia; vitamin B12; amino acids, organic acids and polymers; the immunosuppressant, rapamycin (sirolimus) and antitumour antibiotic, fumagillin; statins; pigments; vaccines (developing media with non-animal components for clostridial vaccines); and evaluating the impact of simulated microgravity on secondary metabolism 1.”^[4][5] Demain's MIT research led to “a breakthrough discovery of a key enzyme in cephalosporin biosynthesis –deacetoxycephalosporin C synthetase ('expandase'). The discovery of this enzyme established the role of penicillin as an intermediate in cephalosporin C biosynthesis and disproved the previous hypothesis that these two separate end products of C. acremonium were formed by a branched secondary metabolic pathway.”

Demain has said that when he first arrived at MIT, “there was no work going on with antibiotics in the Nutrition and Food Science Department. At that point, I was anxious to introduce such studies into the department....I had an interest not only in the 'good' products made by microorganisms, but also in the 'bad' ones. In collaboration with George Buchi, MIT’s great natural product chemist, and Gerald Wogan, a toxicologist, we found that a mold isolated from a Thai household, which had killed a child there, produced three toxins: cytochalasin E and the tremorgens, tryptoquivalin and tryptoquivalone. Our cooperation led to the discovery and structure elucidation of ditryptophenaline from Aspergillus flavus and aspersitin from Aspergillus parasiticus, and the isolation of cyclopiazonic acid.”

Demain further recalled that he “was drawn into the cellulase area by some comments I was asked to present at a symposium dealing with cellulase of the fungus Trichoderma viride (later Trichoderma reesei),” and his work in this field resulted in the discovery “that the extracellular cellulase of Clostridium thermocellum ATTC 27405 could attack crystalline cellulose,” which was “the first demonstration of a true cellulase produced by a bacterium.” This enzyme later proved to be “useful in the conversion of cellulose to glucose, since it degraded cellobiose, the inhibitor of cellulase action.” An important theory proposed by Demain, which he showed to be valid, was that antibiotics occur in nature and that they help to ensure the survival of the organisms that produce them. This theory was at odds with the prevailing assumption of the day, namely that antibiotics were laboratory artifacts.

In the mid-1990s, Demain and his team “started a series of NASA-sponsored experiments to determine the effect of simulated microgravity (SMG) on secondary metabolism” and “found that regulation of microbial processes under SMG was quite different from that at normal gravity.” In his last MIT projects he studied Clostridium tetani and C. difficile with the aim of facilitating the production of improved tetanus and antibiotic-associated diarrhea vaccines. The effort was successful.^[6] Summing up his years at MIT, Demain later said that he “was very lucky...to have had a fantastic group of bright and hardworking visiting scientists, postdoctoral associates, graduate students, undergraduate students and high school students. I owe all my success to them and my two amazing lab supervisors, Nadine A. Solomon and Aiqi Fang....Success at MIT would not have been possible without them.”^[6]

Cetus Corporation

Demain has said that “the explosion of the biotechnology field” in the early 1970s “really turned me on to the applications of sciences,” and led to his involvement with “the first biotechnology company, the Cetus Corporation, in Berkeley in 1971.” Demain became an advisor to Cetus, making him “the second consultant in the biotechnology industry,” the first being joining Joshua Lederberg of Stanford.

Demain described his work with Cetus as “one of the most exciting adventures that I have ever experienced. The vision of these Cetus founders resulted in a major industry, serving the needs of patients throughout the world and revolutionizing the practice of industrial microbiology and agricultural technology.” Demain said that Cetus, which was later incorporated into Chiron, now Novartis, “should long be remembered as the founder of modern biotechnology and the developer of the polymerase chain reaction (PCR), a technique of enormous importance today.”^[6]

Drew University

In 2001, Demain became one of a small group of Research Fellows pwcat the Charles Dana Research Institute for Scientists Emeriti, or RISE, at Drew University in New Jersey. In this capacity he trains undergraduate students in conducting research in microbial chemistry.^[4][5]

Other professional activities

Demain was elected president of the Society for Industrial Microbiology in 1990, and became a member of in the National Academy of Sciences (U.S.) in 1994, the Mexican Academy of Sciences in 1997, and the Hungarian Academy of Science in 2002. He is on the Board of Governors of the American Academy of Microbiology, has served as a member of the U.S. National Committee for the International Union of Microbiological Sciences (IUMS), and was a delegate to the 2002 General Assembly in Paris. He has been honorary consultant for the Fujian Institute of Microbiology and the Shanghai Institute of Pharmaceutical Industry in The People’s Republic of China.^[4] In addition, he is a member of the scientific advisory boards of Tetravitae Bioscience and of Dyadic International, and is also on the advisory board of Codexis, Inc.^[9][10]

Honors and awards

Demain has received honorary doctorates from the University of Leon (Spain), Ghent University (Belgium), Technion (Israel), Michigan State, and Muenster University (Germany).^[4] The August 2010 special issue of The Journal of Antibiotics celebrated Demain's career, noting that he had “established and maintained a renowned reputation within the field of industrial microbiology.”^[11]

References