Microbial Ecology


Sagarmoy Ghosh

Assistant Professor

Dept of Microbiology

Research focus in our lab have been principally in the fields of RNA regulation in Hepatitis B virus (HBV) and in Burkholderia sp., a major pathogen in nosocomial infections. Our secondary research focus is on ecological characterization of microbial population important for agriculture by 16S rRNA diversity.

In HBV, we could demonstrate an intronic splicing regulatory cluster in its pregenomic RNA. This was the first report of any splicing regulatory component in HBV. We are also exploring metazoan factors that take part in nuclear retention of this pre-mRNA. As HBV utilizes host machineries for maturation and expression of its gene products, information gathered will help understanding of HBV biology and also controls in pre-mRNA maturation pathways. In Burkholderia sp., we are asking how this bacteria survives in an iron-deplete environment in lung of immunocompromised individuals. We are looking into small RNA and Hfq mediated controls that could be triggered by iron depletion in the environment.

In microbial diversity studies undertaken in my laboratory in collaboration with Dr. Kalyan Chakrabarti, Department of Agricultural Chemistry and Soil Science of University of Calcutta, we demonstrated that overall biochemical activity of different populations of bacteria remain same under different fertilizer regimes even though the constituting members in individual niches could be different. In other words, different consortia of bacteria can display similar biochemical properties as a population. In a separate study we isolated and characterized diazotrophic bacteria that can be used as biofertilizer in high salinity areas to increase crop productivity.


Maitree Bhattacharya

Associate Professor

Dept of Biochemistry

Protein structure and function

Oxidative stress and Diabetes Mellitus

Hemoglobin and Red blood Cell

Chronic Arsenic toxicity, role of nutrition and oxidative stress

Microbial ecology

Leghemoglobin–biochemical and biophysical characterisation


Prasanta Kumar Bag

Associate professor

Dept of Biochemistry

Pathogenesis of enteric bacteria:Our laboratory is involved on isolation and characterization of enteropathogens from environmental samples, to elucidate the ecology and public health significance of these enteropathogens in the aquatic environment. Monitoring existing environmental strains and undertaking detailed studies of how pathogenic strains evolved from them is essential to our understanding of human disease. Our laboratory demonstrated that Vibrio cholerae non-O1, non-O139 and Aeromonas hydrophila isolated from natural surface water from different sites sampled in diarrhea endemic zones in Kolkata were having pathogenic potential. We have also developed a simple latex agglutination based diagnostic technique for detection of Shiga toxin-producing Escherichia coli. Our present focus is on the mechanism of pathogenesis of some enteric bacteria.

Antimicrobial activity from medicinal plants: Emergence of resistance to multiple drugs is a serious clinical problem in the treatment and containment of the disease. Ethnopharmacology and natural product drug discovery remains a significant hope to solve that problem. Our research interest is on isolation, purification and characterization and mechanism of antimicrobial activity against enteropathogens from medicinal plants. We have demonstrated the antibacterial, antisecretory and antihemorrhagic activities of Azadirachta indica.

Molecular principles of species interaction in the rhizosphere of a leguminous plant: Biochemical and Metagenomic approaches-While unraveling molecular mechanism of rhizobium legume interaction has attracted the most scientific attention little is known about the community character of the microbes in the rhizosphere of legumes. Establishing a link between microbial diversity in the rhizosphere and the role they play in the natural ecosystem is a major challenge. While rRNA profiling gives an idea of the gross biodiversity, monitoring diversity of functional genes gives an idea about the biochemical interdependence of the community. Some of the functional genes, for example lipase, can be both ecologically enlightening as well as commercially useful. Our laboratory is involved on determination of the microbial community composition (culturable and unculturable) within and outside the rhizosphere of an oil seed legume (Arachis hypogea) on the basis of variations in lipase/esterase specific genomic loci with a view to understand effect of plant-microbe interaction in the respective soil ecosystem. Also the application potential of the identified lipase/esterase (s) would be evaluated.


Rajat Banerjee


Dept of Biotechnology

Transcriptional regulation of AlaRS Induced conformations and amino acid discrimination during substrates binding of plant arginyl-tRNA synthetases (In collaboration with Professor Gabor Igloi, University of Freiburg, Germany)

Evolution of Glutamyl-Q- tRNAAsp Synthetase (In collaboration with Professor Daniel Kern, University of Strasbourg, France) Mechanism of substrate recognition by truncated glutamyl-tRNA synthetase (In collaboration with Professor Gautam Basu, Bose Institute, Kolkata, funded by Council for Scientific and Industrial research, Govt of India)

Structure-function studies of tyrosyl-tRNA synthetase (TyrRS) from Mimi virus (Acanthomoeba polyphega) Secret Sharing Scheme Using DNA Cryptography (In collaboration with Dr. Avishek Adhikari, department of Pure Mathematics, University of Calcutta; funded by Ministry of Information Technology, Govt. of India.)

Isolation, identification and characterization of biodegradable polyester from bacterial sp. (In collaboration with Dr. Sumana Chatterjee, Department of Chemistry, Basanti Devi College, Kolkata)


Alok Kumar Sil

Assistant Professor and HOD

Dept of Microbiology


Sukhendu Mandal

Assistant Professor

Department of Microbiology

The major research interests are:

1.Role of alternate sigma factors in Mycobacterial gene expression. Studies on the alternate RNAP holoenzymes and transcription factors involved during stress.
2.Identification and characterization of novel inhibitors of M. tuberculosis and S. aureus RNA Polymerase focusing on traditional ethnic medicinal plant products.
3.Isolation and characterization of novel bacterial species based on their hydrocarbon or rubber degradation properties.
4.Identification of novel Actinomycetes for their unique antimicrobial components.


Dr. Sanjay Ghosh

Associate Professor

Dept of Biochemistry, University of Calcutta

Microbial Ecology

Isolation, Production and Properties of industrially important cellulase and xylanase enzymes from fungus:

ExtremophilicCellulases and xylanases have lot of application in several industries like textile industry, Paper pulp industry, household purposes like, jam cleaning etc. We first time isolated cellulose and xylanase producingPenicilliumcitrinumand Simplicilliumobclavatumfrom soil. We have developed a bioprocess for production of endoglucanase and xylanase using solid-state fermentation in a small scale.

Microbial synthesis of silver and gold nanoparticles and their applications.

The field of nanotechnology has received major advances in various aspects of technology from sensors to the application of medicine. Our focus is on the environmental friendly synthsis of nanoparticles, the so called Green Chemistry. We are involved in identifying the factors which control the size and shape of the fungal cell synthesized silver and gold nanoparticles. We are also involved in studying the mechanism of synthesis of gold and silver nanoparticles. Our future objective is focused on the application of biologically synthesized nanoparticles.