Moringa oleifera seeds are known to have coagulant and antimicrobial properties. Scientists have suggested using the seed extract to purify water. However, the process has not been optimised.
Recently, Saurabh Kulshrestha and team from the Shoolini University, Solan collaborated with scientists in China to report optimising the antibacterial activity of moringa seed extract. They have also developed a dip-bag containing moringa seed powder to be used as portable water purification kit.
The researchers used an aqueous extract of moringa seed to qualitatively assess its antimicrobial property. Using agar well diffusion assay they tested its bactericidal and bacteriostatic properties on Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Methicillin-resistant Staphylococcus aureus. With ampicillin as positive control, they found that hundred milligrams per millilitre of the extract was the minimum inhibitory concentration.
The scientists used a semipermeable dip-bag containing moringa seed powder to tweak the minimum time and seed quantity required for antibacterial activity against the test isolates. The researchers found that, in five minutes, a hundred milligram moringa seed powder dip-bag, in one litre of water, effectively eliminated all four bacterial isolates.
They replicated the experiment with contaminated water from natural sources and confirmed its effectiveness in field conditions. Contaminated water may contain microorganisms, silt, clay and other impurities. With further research, development and testing, the kit may prove useful in defence, disaster management and during drought.
Can moringa seeds replace alum and other chemicals used in water purification? What are the active principles in the extract that inhibit microbes? Can we use them to treat infections?
Each solution in science breeds more questions. Meanwhile, can villagers who have access to moringa seeds use them to make drinking water safe?
J. Water Process Engineering, 27: 37-46 (2019); DOI: 10.1016/j.jwpe.2018.11.005
Freelance Science Writer, Bengaluru