Biopesticide in the making

THIRUVANANTHAPURAM: In a week that witnessed scientists from University of California coming up with a scientific way to read people’s mind, back home at the Kerala Science Congress, research scholar Renju Krishna bagged the Young Scientist Award in the Life Science category.Renju snooped around the microbial world and found an enzyme that could actually digest disease-causing fungal parasites on plants. This could someday be developed as a biopesticide.  Renju found the enzyme, chitinase, in a soil bacteria that uses it to attack organisms that have chitin in them. Just as in the shells of crabs, lobsters and shrimps, chitin is found in the cell walls of parasitic fungus. The bacteria chew up the chitin in the fungus using this enzyme, thus effectively killing the parasite. By the same principle, the enzyme can break down bio-waste (shells of shrimps) from the seafood industry. And it is not just one fungus that this enzyme can kill. Be it the Helminthosporium that causes leaf blights and blister cankers on apple, the aspergillus that can cause black moulds on fruits or the fusarium species that produces toxins in cereal crops, chitinase is nemesis to all.Precisely why this might be the first step to developing an alternative to chemical pesticides, a bio-tool instead of a chemical one. And that too, something straight from a natural enemy, straight from nature.’What is very special about Ranju’s work is that it is for the first time that this particular kind of enzyme is being isolated from this bacteria called Streptomyces californicus. The enzyme, a Family 19 chitinase, is generally seen only in plants and one another species of Streptomyces,’’ said Renju’s guide N S Pradeep, who is a senior scientist at the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI). Renju is doing her PhD at JNTBGRI guided by Pradeep and A Gangaprasad, faculty member at the KU Department of Botany.