When Muniasamy Neerathilingam was studying in Chennai's Anna University two decades ago, he contracted a painful skin condition because of the heat. He visited a dermatologist, but the ointment he was prescribed didn’t help much.

When he went home to Rajapalayam for his holidays, however, his mother gave him tender coconut water every day and his skin condition disappeared.

Years later, remembering this experience would lead him to a valuable breakthrough, and a pending global patent covering 180 countries. Munish, as he is called by his friends and colleagues, has found a way to use coconut water as a medium for growing bacteria that significantly reduces laboratory costs.

The breakthrough came last summer, as he attempted to beat the heat by sipping coconut water. Munish, who is now the head of a biotech research department at Bangalore's National Centre for Biological Sciences, realised that the coconut water was very sweet and very sterile, safe from microorganism or harmful toxins.

"It had cured me once,” he said. “I wanted to see if it could it be used to grow bacteria that serve as the environment for creating life-saving proteins."

Bacterial and yeast-based cultures are media for growing proteins – the building blocks of many important drugs, such as insulin.

At present, salt-based media and the Luria broth, derived from animal sources, are common bases for growing bacterial cultures. But salt-based media require careful preparation, and Luria broth contains harmful toxins that need to be removed if they are to form a base for making proteins. Tender coconut water is free of both these drawbacks.

"Luria broth is beyond ubiquitous," said Sangeetha Iyer, a post-doctoral researcher at the University of Austin, Texas. It is used in almost any context in which bacterial cultures need to be grown but costs Rs 25,000 or more per kg.

Munish set his students the task of conducting experiments to test tender coconut water as a medium for breeding bacterial cultures. Their experiments confirmed that it was indeed a good base for brewing cultures, resulting in yields comparable to those of Luria broth cultures and salt-based media. A few more experiments later and they had established that bacterial cultures grown in tender coconut water did yield proteins as efficiently as bacteria grown in other media.

The team discovered that supplementing coconut water with ammonium salts – a common byproduct of chemical processes – standardised results from coconuts bought from various places. Their new medium is a tenth of the price of the other media.  Not surprisingly, an American biotech company expressed interest after they published their findings.

However, other researchers say that that there could be challenges in using coconut water in laboratory or industrial settings.

"Luria broth has a very high shelf life, as it comes as a dry mixture," said Himanshu Sinha, faculty member at the Tata Institute of Fundamental Research in Mumbai. "As coconut water is liquid, it could get contaminated."

He suggested that the money labs save by using tender coconut water would have to be spent on preserving the medium. "There is no doubt that tender coconut water is a good substitute,” he said. “But only research labs or pharma companies can tell us if it is indeed cheaper."