2023

The Department of Zoology, Deshbandhu College, University of Delhi under the dynamic leadership and guidance of respected Principal Sir, Prof. Rajiv Aggarwal, organised an International Webinar on “Ecology and Evolution of Bacterial Interactions” on 17th April, 2023 under the aegis of DBT Star College Scheme and IQAC. Dr. Samir Giri from Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Germany was the invited speaker. The aim of this webinar is to draw the attention of our students towards the fascinating world of Evolutionary Biology, which is not just subject but a unifying thread that joins all organisms from prokaryotes to highest of eukaryotes. Dr. Samir started the session by showing how bacteria live in communities and there are different implications of bacterial interactions. Interactions between multiple bacterial colonies may be antagonistic or synergistic. Exchange of metabolites in synergistic interactions can include unidirectional, bidirectional and cooperative cross-feeding. Further, he explained the conclusions of various laboratory experiments he conducted, in which different auxotrophic and prototrophic bacteria were cultured together. 25 different amino acids prototrophic donors and 4 amino acid auxotrophs (histidine and tryptophan) as recipients of Acinetobacter baylyi and Escherichia coli were used. Empirical data supported that high metabolic and phylogenetic dissimilarity promotes cross-feeding. He also focussed on the ecological niche of these cocultures including environmental factors, which influence growth, survival and reproduction of a genotype. Usually population interactions are thought to contract the niche for one or both the species but in the case of synergistic interactions, niche expansion was observed. Dr. Giri also emphasized on different intrinsic and extrinsic factors that affect the gut bacteria in our bodies. Drugs, both antibiotics as well as non-antibiotics, were seen to have the most negative impact on the gut microbiome. Moreover, these drugs can increase the resistance of bacteria against them. On the contrary, microbes in our body were also observed to affect the action of drugs on our body by metabolising or bioaccumulating it. Towards the end, Dr. Samir Giri also recommended great books like 'Missing Microbes' and 'Invisible Friends' for the people interested in learning more about good bacteria of our body. The participants were enlightened as the meeting was nearly full to its maximum capacity throughout the talk. Moreover, the chat box was flooded with amazing questions and Dr. Samir answered all of them patiently. Overall, the discussion was very informative and thought provoking for our dear students.