Baij Nath Singh obtained DSc (1947) from University of London, UK. He worked as Senior Scientific Officer, Department of Soil Microbiology, Rothamested Experimental Station, England. After returning to India, he joined as Assistant Director and Head, Department of Microbiology (1952-64), Deputy Director (Microbiology) (1965-75), Retired Scientist of CSIR (1975-80) and Emeritus Scientist (1980-85) at Central Drug Research Institute, Lucknow.

Academic and Research Achievements: Singh did phylogenic classification of amoebae based on their nuclear division patterns. Dr Singh and his colleagues showed, that some aerobic free-living amoebae could cause fatal human meningoencephalitis. Their work helped in establishing the taxonomic status of these amoebae. The virulence of Entamoeba histolytica has been enigmatic whether an inherent character of some stains or acquired as a result of the environmental factors, and has been a controversial matter. Singh and his colleagues demonstrated that avirulent strains of E. histolytica could be made virulent by feeding them with chelesterol in culture. This is well accepted now. They also made significant contribution to the phenomenon of excystation and encystations, which has importance for the understanding of the epidemeology of amoebiasis. He decided to use free living amoeba as the models as only one amoeba emerge following exceptation in contrast to eight daughter amoebulae of E. histolytica cysts and the results are, therefore, easy to quantitate. It was shown that bacteria and bacterial extracts caused excystment, and that amino acids present in the extract were mainly responsible for excystment, and glumatic acid and cystein were the most active. This also led to study of the phenomenon of encystations and it was shown cAMP aided encystation.

Other Contributions: Singh served as Editor-in-Chief of Indian Journal of Parasitology; Editor of Indian Journal of Microbiology; and Member, Indian Society for Microbiology, Parasitology and Protozoology.

Awards and Honours: Dr Singh won the Silver Plaque by Association of Microbiologists of India (1979) and GP Chatterjee Memorial Lecture Award by INSA (1983). He was elected Fellow of the National Academy of Sciences (India), Allahabad; Honorary Fellow of the Indian Society of Protozoology; Vice-President, Association of Microbiologists of India; President, Agricultural Section, Indian Science Congress (1960).