Hot springs of Jakrem and Sikkim helped Rakshak Kumar come across a heat-loving microbe useful for industrial applications, says Nawaz Yasin Islam
THERMOPHILIC BACTERIA, one of the earliest bacteria found on earth, are less studied but important group of microorganisms due to their ability to produce industrial enzymes. A thermophile is an organism that thrives at temperatures between 45 and 122 °C (113 and 252 °F).
These microorganisms have gained worldwide importance due to their tremendous potential to produce thermostable enzymes that have wide applications in pharmaceuticals and industries.
Thermophilic bacteria have been reported from diverse habitats such as geothermal sites and hot springs. Their enzymes make them withstand high temperatures unlike other types of bacteria. Some of these enzymes are used in molecular biology (for example, heat-stable DNA polymerases for PCR), and in washing agents.
Rakshak Kumar (Acharya), a product of St. Anthony’s College who did his PhD from North Eastern Hill University, was awarded a Research Associateship award by Departmment of Biotechnology, Government of India, to work on a project titled ‘Study of thermophillic bacteria from the hot springs of North East India and its industrial applications” under the supervision of P Anil Dr Kumar, scientist at Institute of Microbial Technology (CSIR), Chandigarh.
Scientist TNR Srinivas from CSIR-National Institute of Oceanography, Visakhapatnam helped him with molecular phylogenetic approach.
Kumar possibly never anticipated that he would be a ‘discoverer’ after finding the heat-loving bacteria. “We explored the bacteria from four hot springs of Sikkim and Jakrem of Meghalaya. Hot springs have extreme environment condition evident of rich diversity and the bio-prospecting of heat loving bacteria may provide thermostable novel enzymes with industrial application,” Kumar said. He added that while studying the hot spring of Jakrem they obtained a bacterial strain designated AK31T which was previously uncharacterized or in other words never known to science earlier. The bacteria thus earned the name Caldimonas meghalayensis, the second word meaning ‘belonging to Meghalaya’.
“It was my dream since I started research in microbiology in 2005 to find such bacteria from my home state, bacteria that would carry the state’s name,” Kumar said. In the classification of bacteria, Caldimonas genus falls under the class Betaproteobacterium.
The journey to success was arduous. “First we had to go to collect samples from different hot springs, take the water and sediment sample aseptically to our lab in MTCC, IMTECH, Chandigarh and then isolate bacteria who survives above 50°C. After we confirmed those were pure bacteria, we proceeded further. About 200 pure bacteria were obtained from all the hot springs and three of them were found to be novel. This one C. meghalayensis was found from Jakrem,” Kumar said. SR Joshi from NEHU provided him the lab facility for isolating the bacteria and Macmillan Nongkhlaw helped him in sample collection.
The novelty of the bacteria came from matching the 16S rRNA gene sequences with the sequence data available in their database. Following a set of experiments in the line of polyphasic taxonomy, Kumar came to the conclusion that the sample was that of a novel bacterium. Experiments were performed together with two reference strains collected from Japan and Belgium.
Elaborating the possible avenues that could be explored by the isolation of microbes from hot springs, Kumar said, “Such hot springs are popular in the region for their therapeutic properties but no report in literature suggests exploration of diverse thermophillic bacteria from these springs. The thermophiles (heat loving bacteria) present a source of highly thermostable enzymes which could work at high temperatures thus widening the range of their applications. These enzymes have commercial utilization for their inherent stability.”
The bacteria, owing to tolerance of higher temperature, produce polyhydroxybutyrate (PHB) granules that can be generated on a large scale. PHBs are polymers belonging to the polyester class that are of interest as bio-derived and biodegradable plastics. Other industrially important enzymes produced by the thermophillic bacteria are amylases and ureases.
Kumar’s discovery could thus be a significant one in the field of microbial research.