Subir Kumar Nandy

Subir Kumar Nandy

UNIBIO A/S, Denmark

Title: Towards a green future: bacterial biomass used for feed


Subir Kumar Nandy (m), is a Senior Fermentation Specialist and responsible for Unibio’s fermentation facilities at DTU. Subir has a PhD in Chemical Engineering from Indian Institute of Technology, Bombay in India, and did two postdoctoral works at the Chalmers University of Technology in Gothenburg, Sweden, and at the Technical University of Denmark (DTU). He has performed fermentation biomass composition analysis, kinetic modelling, fluxomics and other omics analysis, and used novel biological methods. He has teaching activity and supervised Bachelor/Diploma/Masters/PhD student works in these fields. He joined the Unibio team in January 2015 with responsibility for developing and improving Standard Operating Procedures as well as developing the optimal medium composition for running fermentations in the lab-scale fermentor and U-Loop. He is involved in most Unibio projects. He has more than ten years of experience in fermentation.


Demand for animal protein (meat) will increase due to the combined effects of population growth and increasing standards of living in the world. This will lead to stronger demand for traditional major sources of protein used in commercial livestock feeds. The supply of these proteins is limited and cannot be increased without e.g. resulting in land use changes or adding unsustainable pressure to ocean fish stock. Methylococcus capsulatus is a methanotroph that contains 70% protein when grown under aerobic conditions. The high content of protein makes M. capsulatus biomass attractive for use as feed material. Process development efforts have been made, resulting in the use of a U-Loop reactor for continuous production of biomass using M. capsulatus as the main population and three other bacteria in smaller quantities in the culture, utilizing methane from natural gas as the carbon source. In this paper we present the preliminary results of the operation of a pilot plant 100 L U-Loop reactor. All four bacteria are non-GMO, and their use as feed material has been approved (EU Commission Regulation No 575/2011, Section 12.1.2). The environmental virtue of the process lies in the fact that it is able to exploit excess natural gas which will otherwise be vented and/or burned, producing carbon dioxide. Thus, the process paves the way for realizing a circular economy where waste is used to produce a useful material. The application of this process also releases land used for producing feed for other uses, as the same amount of protein can be produced using significantly smaller areas of land.