Hirendra Kumar Das earned his BSc (Hons), MSc (Tech), PhD and DSc degrees from Calcutta University. Das worked as a Research Associate with Professor Avram Goldstein in Stanford University (1964-67). Back in India, Das joined the Indian Agricultural Research Institute (IARI), New Delhi. In 1976 Das moved to the Jawaharlal Nehru University (JNU), New Delhi.
Academic and Research Achievements: Das worked on glutamate metabolism in plant mitochondria where 85% of it was found to be channeled through glutamic dehydrogenase unlike in liver mitochondria, where most of it was routed through the transaminase step. He discovered that plant mitochondria could synthesize proteins. Das detected about 10 micro g DNA per mg protein in mitochondria and demonstrated that the DNA was replicated, transcribed and translated in mitochondria. This was indeed a striking revelation in the early sixties. At Stanford University he demonstrated, for the first time, that transcription and translation in Escherichia coli are coupled. Das also deciphered the mechanism of inhibition of protein synthesis in Escherichia coli by chloramphenicol. At IARI, he initiated teaching and research in Molecular Biology. Das investigated lysine deficiency of wheat proteins. He found that proteins in immature endosperm had sufficient lysine, but synthesis of lysine rich proteins declined with maturation. Besides, lysine rich proteins synthesized early were later degraded preferentially through a specific protease. At JNU, he initiated teaching and research in Recombinant DNA Technology. He took interest in molecular genetics of nitrogen fixation, and provided the first physical evidence for the presence of three distinct pathways (nif, vnf and anf) of nitrogen fixation in Azotobacter vinelandi. Subsequently Das fished out the nifHDK operon and the regulatory operon containing nifL and nifA from a library constructed in his laboratory and analyzed details of nif regulation. He constructed a constitutive Azotobacter by deleting nifL and replacing the nifLA promoter. This construct can replace about 40kg of urea per hectare of wheat cultivation, hence would be very useful in agriculture. He has published 67 research papers and mentored 19 PhD students.
Other Contributions: Das established the Genetic Engineering Unit at Jawaharlal Nehru University, Delhi. He served in the UGC-DBT committee, which initiated the Biotechnology teaching programme in India and developed the curriculum. He also served in the committee that established the Bioinformatics network in India. He served in the committee that formulated the Genetic Engineering Guidelines for India. Das had also served in the Editorial Board of the Journal of Biochemistry and Biophysics.
Awards and Honours: Dr Das received the Shri Om Prakash Bhasin Award for Science and Technology (1994).