|Born||May 15, 1900
|Occupation||Nutritionist and biochemist|
In 1924 Zheng Ji passed the entrance exam for the Southeast National University (originally known as the Nanjing Advanced Normal School, moving in 1928 to the National Central University, then to the Nanjing University) biology department in 1929. In 1930 he went to America to study, majoring in biochemistry at Ohio State. He also attended Yale and Indiana University, and in 1936 he obtained his PhD.
Upon returning to China he successively served as a research fellow at the Scientific Research Institute of China; as a professor at the Central Medical School; as both a biochemistry professor and department head, simultaneously, at the Eastern China Military Medical School; as a professor at the Number 4 Military Medical College; and as both a biology professor and the head of the biochemistry teaching and research department at the Nanjing Medical School.
In 1945, at the Central Medical School, he established a biochemistry research institute to train graduate students. This was the first formal organization in China to teach biochemistry to graduate students, training a large number of students who went on to work in a variety of fields. After turning 70 he began to study the biochemistry of old age, proposing a theory of metabolic imbalance, forming the basis of geriatric biochemistry in China.
He participated in the establishment of the Chinese Nutrition Society and, later on, the Biochemistry Society. He is a past chairman of the Central University Professors Association and the first council chair of the Chinese Nutrition Society.
Zheng Ji turned 109 in May 2009 and is arguably the oldest professor currently living in China. He spent the greater part of his life teaching at the medical school and biology department of Nanjing University.
In recent years he has sold off family property, such as his family home, using the proceeds to make donations both to the university and to society at large, and to set up both a scholarship for needy students and a scientific endowment.