Banaras Hindu University scientists discover new ‘metal eating’ bacteria

VARANASI: In a significant breakthrough, scientists at the Indian Institute of Technology, Banaras Hindu University (IIT-BHU), have discovered a bacteria that can separate toxic cancer-causing metal — hexavalent chromium — from water and make it safe for use. The research has been published in the reputed international journal, ‘Journal of Environmental Chemical Engineering’. The new bacterial strain has been named ‘Microbacterium paraoxydans strain VSVM IIT (BHU)’.
Dr. Vishal Mishra at the School of Biochemical Engineering, IIT (BHU), and his Ph.D student Veer Singh have isolated a new bacterial strain from a contaminated site which can remove toxic hexavalent chromium from wastewater. Hexavalent chromium is a heavy metal ion that is responsible for several types of health problems in humans, including various types of cancers, kidney and liver malfunctioning, infertility etc.
Dr. Mishra said, “This new bacterial strain is able to tolerate large concentrations of hexavalent chromium. It is very effective for removal of hexavalent chromium from wastewater compared to other conventional methods. This bacterial strain showed fast growth rate in the Cr (VI) containing aqueous medium and easily separated the aqueous medium after the water treatment process.”
“This bacterial strain is very advantageous because there is no need for an extra separation process after removal. Bacterial mediated wastewater treatment is inexpensive and non-toxic because there is no involvement of costly equipment and chemicals. The researchers have tested hexavalent chromium removal capacity of this bacterial strain in industrial and synthetic wastewater and found satisfactory results. Researchers also tested the hexavalent chromium removal mechanism in the bacteria. Research reported that several heavy metal tolerance mechanisms got activated in bacterial cells when they were grown in the growth medium containing hexavalent chromium,” he added.
This research is focused on the cost-effective and eco-friendly method for removal of toxic metal ions such as hexavalent chromium from water. Bacteria can easily cultivate and remove hexavalent chromium in an effective way. No skilled labour is required for culturing bacterial strain. It is very inexpensive, non-toxic and easy to use. Also, separation after usage does not require large energy input and removes hexavalent chromium until the discharge limit of the Central Pollution Control Board (CPCB).
“Water-borne diseases are a major problem in developing countries. According to the World Health Organization (WHO) 3.4 million people, mostly children, die from water-related diseases each year. According to a United Nations Children’s Fund (Unicef) assessment, 4,000 children die each day due to the intake of bacterial contaminated water. WHO reports that over 2.6 billion people lack access to clean water, which is responsible for about 2.2 million deaths annually, of which 1.4 million are children. Improving water quality can reduce the global water-borne diseases,” Dr. Mishra said.
Cancer caused due to heavy metals such as hexavalent chromium is a severe problem worldwide. The developing countries such as India and China are very prone to heavy metal contamination. Human intake of hexavalent chromium is mainly through skin contact, intake of contaminated water or contamination in food products. The hexavalent chromium causes several diseases in the human body as well as dangerous ones like cancer.
A report of the water resources ministry says a large number of the Indian population drink water with lethal levels of toxic heavy metals, about 239 million people across 153 districts in 21 states drink water that contains unacceptably high levels of toxic metal ions. WHO has warned that long-term intake of water containing toxic heavy metals such as lead, chromium, cadmium and arsenic may cause cancer of skin, gallbladder, kidney or lungs, he said.