The government is now confronted with a cowntroversy of a different kind – that too with microbes for biodigester technology from distant Antarctica.
On August 9, the Defence Research & Development Organisation (DRDO) informed the Rajya Sabha that microbes from Antarctica are to be used as a new biodigester technology in train toilets by the Indian Railways. Defence Minister Manohar Parrikar informed the House that this bacteria from Antarctica was being used in anaerobic microbial consortium that is used for seeding (innoculation) biodigesters. “The consortium is composed of bacteria belonging to four groups, which work in a sequential manner. The Antarctica bacteria which are cold active, constitute the first two groups, hydrolytic and acidogenic.” Cow dung, he informed the House, being abundantly available at low cost, was used for multiplication of the bacteria in the bio-digester.
However, senior scientists have refuted these claims, and accused the DRDO of hoodwinking the public by using only cow-dung instead of the imported bacteria to biodigest the human waste.
In sub- zero temperatures such as Siachen, natural bio-degradation of organic matter does not occur. This leads to accumulation of human waste over the years, contaminating the ice, which is the only source of drinking water, thus posing a health risk. The DRDO first initiated the bio-digester technology to address this problem. Subsequently, imported bacteria through acclimatization, enrichment and bio-augmentation was used. The technology has now been extended to the Indian Railways for on-board treatment of human waste. Biodigester technologies are planned to be used in all trains in the years to come, as also rural homes in many states and union territories, starting with Lakshadweep.
Senior DRDO scientist Dr. Y. Ashok Babu, who has lodged a complaint with the Central Vigilance Commissioner (CVC) seeking a probe into it, says that the imported bacteria worked perfectly well in the laboratory but did not work efficiently in the Siachen region, for which a solar panel heating system was added to accelerate the digestion process.
Dr. S. Shivaji, Former scientist, Center of Cellular and Molecular Biology (CCMB), and presently Director, Prof. Brien Holden Eye Research Centre, adds, “microbes found in Antarctica are psychrophiles (cold loving) and normally survive and multiply at temperatures ranging from minus 2°C to a maximum of plus 30°C temperature. The evolutionary advantage that microbes from Antarctica possess is their ability to survive and multiply below 8°C”. Microbes found in the sub-continent cannot grow below 8°C but can withstand temperatures up to 45°C.
The research initiated several years ago in the CCMB today finds usage in the bio-digesters. However, according to Dr Shivaji, “it is very unlikely that microorganisms from Antarctica could be functional in tropical regimes, especially in railway bio-digestors and in areas such as Lakhadweep”. He adds that the biodigester technology will have to be designed to carry out the digestion process below 25-30°C if they are to be used, which would mean additional technical challenges to control the temperature of the biodigester below 30°C, adding to the cost of the process.
Biodigester technologies have been in use for degradation of human refuse, vegetable waste, kitchen waste, agricultural waste, animal waste including poultry waste, and more. The challenge is that they need to be designed based on the specific input (human refuse, vegetable waste, kitchen waste, agricultural waste, animal waste, poultry waste etc.) into the biodigester for the simple reason that microbes vary in their capabilities to degrade the waste – for instance those that break down feathers may not be best suited for plant fibres or kitchen waste.
It is thus difficult to decide that whether the breakthrough is a reason to rejoice, or whether it is a scientific quagmire that is devised to baffle rather than simplify.