Page 55 - AWSAR 2.0

and other European countries demonstrated the existence of microorganisms in the groundwater and sediment samples, where high As concentrations were reported. Ultimately, an indigenous understanding of this devastating problem and the subsequent solutions would be preferred than the imported knowledge.
A team of young microbiology scholars (Angana Sarka amd Dhiraj Paul) with Dr. Pinaki Sar (Professor) from the Indian Institute of Technology, Kharagpur, started the journey of investigating the microbial world deep within the subsurface groundwater and the physiological role of microbes in As contamination. In the year 2009–10, a large number of groundwater samples from domestic tube wells and sediment samples from drillings of As-hot spot areas of West Bengal (North 24 Parganas, South 24 Parganas, Nadia and Bardhaman) were investigated by A. Sarkar and P. Sar at IIT Kharagpur Environmental Microbiology-Genomics
Laboratory. In 2013–14, Sarkar
et al. published the research
findings in international
journals about the dynamic
microbial community in the As-contaminated groundwater
and the key microbial members (Agrobacterium/Rhizobium, Ochrobactrum,Achromobacter, Pseudoxanthomonas, etc.) with
high As resistance, As and Fe transformation and associated
genes within these organisms.
In 2015, Paul et al., with P. Sar
from the same laboratory, again
published three pioneering
works on the microbial community diversity in the severely As-impacted Chakdaha, Nadia district of West Bengal in the journal Plos One and Bioresource Technology. It has been pointed out that the As-contaminated
Dr Balaram Mohapatra || 31
groundwater harbours microorganisms of different types, namely methanotrophic, syntrophic, fermentative, heterotrophic and facultative anaerobic populations, but not strict respiring organisms such as the ones obtained from European and USA groundwater. With the recent molecular technologies of metagenome (community DNA) sequencing through 16S rRNA gene amplification, denaturing gradient gel electrophoresis, microcosm experiment, etc., they elucidated the role of Proteobacteria, Bacteroidetes and Actinobacteria in the mobilization and biotransformation of As and the crucial mechanisms of As release in the Bengal groundwater. The same laboratory is currently active and known for As- geomicrobiology research. Presently, another group of micromaniac scholars (Balaram Mohapatra and Anumeha Saha with Prof. Pinaki Sar) is currently engaged in looking deep into the As, where a large number of
shallow and deep tube wells and aquifer sediments are being investigated covering a larger area of As-hot spot regions of West Bengal. Recently, 40 groundwater and 30 sediment samples are being collected from domestic wells and underground drilling from Western to Eastern Bhagirathi river of West Bengal to decipher the role of amazing microorganisms in As groundwater, considering the seasonal fluctuation in groundwater table and spatio- temporal and depth variations in tube wells. In 2017, Mohapatra
et al. reported one Rhizobium bacterial member from a tube- well of Kolsur area with the ability to transform As under anaerobic conditions. In 2018, two of the published studies performed by Mohapatra et al. in the
It has been pointed out that the As-contaminated groundwater harbours microorganisms
of different types, namely methanotrophic, syntrophic, fermentative, heterotrophic and facultative anaerobic populations, but not strict respiring organisms such as the ones obtained from European and USA groundwater.