Marjory Stephenson: Bacterial Biochemist and Fellow of the British Royal Society
Miranda Van Rensselaer, Spring 2025
Marjory Stephenson (born January 24, 1885 – December 12, 1948) was one of the most influential scientists of her time, known for her pioneering work in the newly emerging fields of chemical microbiology and bacterial biochemistry. Being one of the first scientists to work with and recognize bacteria as a model organism in her laboratory in Cambridge, she laid the foundation for studying the processes of bacterial metabolism (particularly enzymes), forever changing how scientists study microorganisms. Because of her many contributions to microbiology research, she was one of the first two women ever (the other being Kathleen Lonsdale), to be inducted as a Fellow of the Royal Society in 1945.
Born on January 24, 1885 in Burwell, UK, to Sarah-Rogers Stephenson and Robert Stephenson, Marjory Stephenson had always been encouraged by her parents to pursue education. Her father was the one who sparked her early interest in science, starting with simple explanations on nitrogen fixating processes in plants, while her mother was a strong believer in women’s education in general. Also important in her early life was Stephenson’s governess, who encouraged her parents to let Stephenson apply for the Berkhamsted High School for Girls, in which Stephenson was accepted with a scholarship in 1897. Soon after graduating from Berkhamsted, Stephenson’s mother encouraged her to pursue a university education at the Newnham College in Cambridge. There, in 1906, Stephenson earned a “certificate of proficiency” in chemistry, zoology, and physiology, as women at the time were not allowed to be awarded actual degrees (Štrbáňová, pg 1-3). It was also at Cambridge where she met her future lab supervisor and mentor, F.G. Hopkins, a biochemist. Wanting to initially pursue a career in medicine, financial constraints caused her to take up teaching positions in different places, such as King’s College for Women, where she impressed Robert. H. A. Plimmer, a physiological chemistry professor at University College London, to be a part of his research group (Štrbáňová, pg 5-6). Under Plimmer’s research guidance, she began to study enzymes, publishing her first paper On the Nature of Animal Lactase in 1912 on lactase, an enzyme found in the dog intestine (Štrbáňová, pg 7). Impressed by her work and research, F.G. Hopkins approached her and invited her to join his lab in Cambridge. This is where the majority of her biochemical discoveries take place.
An enthusiastic and passionate mentor to Stephenson, Hopkins encouraged her to pursue the undiscovered field of bacterial biochemistry, thanks to his fascination with microbes (Štrbáňová, pg 21). Stephenson, though initially disappointed with this fascination, eventually developed her own love of the field, studying enzyme adaptation and activities in bacterial cells. Stephenson was one of the first scientists to see and use microorganisms such as E. coli as model organisms, and one of her most important findings was E. coli’s tendency to shift from being an anaerobic microorganism to an aerobic microorganism under different environmental conditions, giving important insight to how microbes adjust to changes in their environment (Štrbáňová, pg 22). Her newfound passion for working with microbes led to the creation and development of several new techniques still used in laboratory research today, including the “resting cell method” and “balance sheet technique” (Štrbáňová, pg 30). Her “Washed Cells Technique” was probably one of her most important techniques, as it allowed her to be the first person to isolate an enzyme from a bacteria: Lactic Dehydrogenase from E. coli. In this method, the bacterial cells were washed and suspended in a minimal medium, which decreased the rate of their metabolism and allowed her to study in greater detail how bacteria break down chemical compounds (“Marjory Stephenson, 1885 - 1948”). In fact, she was one of the first scientists to catch onto the fact that if a biological system was to be understood, a complete study and understanding of the entire organism in which that system resides is crucial (Sargent and Sawers, 2022). Her fascination with enzymes only furthered in 1928 when working with another colleague in her lab, L.H. Strickland. Their focus was on how hydrogen was transferred between chemical compounds in metabolic reactions and realized that there must be an enzyme that is responsible for this process, leading to the discovery of a new type of enzyme which they called “Hydrogenase” (Sargent and Sawers, 2022). Their famous paper, Hydrogenase: a bacterial enzyme activating molecular hydrogen, is still referred to as one of the most important biochemical discoveries of its time.
As her research journey continued, she mentored and hosted a large number of people in the laboratory, including John Yudkin, who “made public the first general theory of enzyme adaptation” (Štrbáňová, pg 38) and Ernst Gale, who discovered the aspartase I and aspartase II enzymes in E. coli (Štrbáňová, pg 41). In 1936 she was finally awarded a Doctor of Science degree from Cambridge University, though the university did not offer to make her a permanent part of the department until several years later (Štrbáňová, pg 48). This highlighted one of her toughest battles to fight in the scientific community: gender equality. Being both involved in the Biochemistry Department of Cambridge University and the Medical Research Center (MRC), Stephenson was respected by many for her scientific intellect and laboratory skills; however authority figures within the university questioned her leadership ability to run and manage a laboratory as well as a man could (Štrbáňová, pg 48). In fact, when viewing actual documents at the National Archives earlier this March, there was one document that summarized all of the current work going on under Stephenson’s supervision, only her name and collaborators were crossed out in pen and replaced with the phrase “in this unit” (Stephenson et al., 1947-8). Eventually breaking these gender barriers, she was finally recognized by Cambridge University as its first Reader in Chemical Microbiology in 1947, a permanent position of authority. This position was unfortunately short-lived, as she died of cancer the following year in 1948.
Stephenson published her most influential and important work, the monograph Bacterial Metabolism, as early as 1930 (Štrbáňová, pg 87). This textbook aimed to be a concise summary of the most important papers, concepts, and discoveries regarding the chemical processes of microorganisms which at the time were scattered all over the place and highly unorganized, as given in the preface:
“The aim of this book has been to choose from the mass of data on the chemical activities of bacteria facts which may help us to gain an insight into the essential chemical processes accompanying the life of the organisms concerned. To form any coherent picture of these happenings is at present beyond our powers…” (Stephenson, 1950).
It underwent a total of three revisions, each one showing the rapid evolution of the newly formed yet fast-growing field of chemical microbiology, with the last one being published posthumously in 1949 (Štrbáňová, pg 90). This textbook laid the foundation for the experimental processes and procedures that are used to study bacteria today, influencing and educating hundreds of scientists in the techniques of bacterial culture.
Stephenson was also eager to organize a Society of General Microbiology (1944) with other prominent British microbiologists and biochemists. This society aimed to be an organization in which scientists could come together and establish a common ground for every type of microbiology. Even though she was encouraged to lead the society as its first president, she handed the role to Sir Alexander Fleming, possibly due to having developed cancer (Štrbáňová, pg 94-5). This was Europe’s first and largest society for Microbiology, showcasing Stephenson’s collaborative nature. However, in 1947 Fleming stepped down and Stephenson took his place, though her presidency only lasted a year before her death in 1948 (Štrbáňová, pg 98). 1947 was also the year in which she, along with Kathleen Lonsdale, became one of the first two women ever to be elected as a Fellow of the Royal Society, a position only reserved for men at the time, a testament to her important contributions to microbiological research (Štrbáňová, pg XIX).
Marjory Stephenson passed away on December 12, 1948, at the age of 65, due to terminal cancer. Despite often being credited as the “founder” of chemical microbiology, Marjory Stephenson is not as well-known as some of her collaborators, such as Sir Alexander Fleming, Ernest Gale, or Sir Hans Krebs, keeping a quieter profile. Gender inequality also likely played a key role in her name not being well-known. However, for many scientists, she was remembered as both a pioneer and a caring mentor in the fields of chemical microbiology, biochemistry, and the newly emerging field of molecular biology. Today, her pioneering work on enzymes and bacterial metabolism continues to influence scientists and researchers alike.
Bibliography
“Marjory Stephenson, 1885–1948.” Obituary Notices of Fellows of the Royal Society 6, no. 18 (November 1949): 562–77. https://doi.org/10.1098/rsbm.1949.0013.
Sargent, Frank, and R. Gary Sawers. “A Paean to the Ineffable Marjory Stephenson.” Microbiology 168, no. 3 (March 2022). https://doi.org/10.1099/mic.0.001160.
Stephenson, Marjorie. Bacterial Metabolism. London: Longmans, Green and Co, 1950.
Stephenson, Marjory, and Leonard Hubert Stickland. “Hydrogenase: A Bacterial Enzyme Activating Molecular Hydrogen.” Biochemical Journal 25, no. 1 (January 1931): 205–14. https://doi.org/10.1042/bj0250205.
Stoneman, Walter. Marjory Stephenson. 1940. National Portrait Gallery, London. © National Portrait Gallery. https://www.npg.org.uk/collections/search/portrait/mw146870/Marjory-Stephenson. Accessed April 13, 2025.
Štrbáňová, Soňa. Holding Hands with Bacteria: The Life and Work of Marjory Stephenson. Berlin, Heidelberg: Springer, 2016. https://link.springer.com/book/10.1007/978-3-662-48482-4.
Van Rensselaer, Miranda. “A Proposed Society for General Microbiology.” UAH Archives, Special Collections, and Digital Initiatives. Accessed May 2, 2025. http://libarchstor2.uah.edu/digitalcollections/admin/items/show/14987.
Van Rensselaer, Miranda. “Hydrogenase: A Bacterial Enzyme Activating Molecular Hydrogen.” UAH Archives, Special Collections, and Digital Initiatives. Accessed May 2, 2025. http://libarchstor2.uah.edu/digitalcollections/admin/items/show/14993
Van Rensselaer, Miranda. “Group for Research in Chemical Microbiology for Cambridge University, 1947–1948.” UAH Archives, Special Collections, and Digital Initiatives. Accessed May 2, 2025. http://libarchstor2.uah.edu/digitalcollections/admin/items/show/14985.
Van Rensselaer, Miranda. “Society for General Microbiology List of Original Members (1944).” UAH Archives, Special Collections, and Digital Initiatives. Accessed May 2, 2025. http://libarchstor2.uah.edu/digitalcollections/admin/items/show/14986.
Van Rensselaer, Miranda. “Topics in Marjory Stephenson's Bacterial Metabolism Monograph, Third Edition.” UAH Archives, Special Collections, and Digital Initiatives. Accessed May 2, 2025. http://libarchstor2.uah.edu/digitalcollections/admin/items/show/14990.
Acknowledgments
Funding for this Study Abroad Class was provided by the UAH Honors College. I would also like to thank Reagan Grimsley for being a research mentor, as well as the staff at the UK National Archives and Wellcome Collection for providing me the archived materials and the UK National Portrait Gallery for granting me a license to use a photo for the completion of this project. I would also like to extend a thanks to my parents, Mike and Kristy Van Rensselaer.