Antibacterial properties of cyanobacteria: A cost-effective and eco-friendly approach to control bacterial leaf spot disease of chilli

摘要

Excessive use of toxic chemicals for controlling crop diseases has caused unprecedented ill-effects on the environment. The growing concern about the harmful effects of such chemicals has necessitated the need for a change in our approach to manage crop diseases in an eco-friendly manner. Search for alternatives with less harmful effects on the environment attracted scientists to look for biocides from plants, including those of microbial origin. This has particular concern for countries like ours where agriculture is the prime occupation. Cyanobacteria, which constitute a versatile group of microorganisms, occur in diverse habitats ranging from alkaline hot springs to permanent snow fields in the poles. In addition to their ability to fix atmospheric carbon, many cyanobacteria are capable of fixing molecular nitrogen. Certain cyanobacterial species are known for their toxin-production properties. Three such strains namely Lyngbya majuscula, Microcystis aeruginosa and Plectonema boryanum were tested for their antibacterial properties towards the control of leaf spot disease of chilli caused by Xanthomonas vesicatoria. First reported in 1953 at Pune5, the bacterial leaf spot disease has become a problem in most of the chilli-growing areas in the country, including Rajasthan. With distinctly raised spots on chilli leaves, this bacterial disease causes great economic loss to the farmers.