Enhancing Crop Production using Streptomyces sp. NCIM 5814 for Simultaneous Biocontrol of Erwinia carotovora, Xanthomanas campestris and Xanthomonas axonopodis

Abstract

Bacterial infections caused by phytopathogens like Erwinia carotovora (Ec), Xanthomonas campestris (Xc) and Xanthomans axonopodis (Xa) detoriate important crops like rice, tomato, pomergranate, chilli, citrus crops, and other vegetables causing loss in food produce and economy. The rapid propogation of these phytopathogens make it difficult to control their spread. The chemicals in form of pesticides and insecticides worsen the situation and cause negative impact on soil productivity, environment and human health. To overcome this, microbial agents like actinobacteria are being employed as source of sustainable farming. In the present study 76 actinobacteria were isolated and tested for their ability to control Ec, Xc and Xa. The primary screening revealed 12 potential isolates that could counter all three pathogens. Isolate P2 and T2 exhibited highest inhibition zone against all three pathogens in secondary screening. The 16S rRNA study revealed that both actinobacterial species were closely related with Streptomyces erumpens. In-vivo treatment of the antibiotic produced by actinobacterial isolate P2 was carried out on Solanum lycopersicum and Capsicum frutscens in field conditions. The plants infected with phytopathogen were treated using crude antibiotic extract (CAE) that protected the plant from disease and also improved its growth. It was observed that the shoot length of treated plants were 33-37% higher in Capsicum frutscens. The CAE enhanced the plant weight by 69-135% in Solanum lycopersicum and 22-114% in Capsicum frutscens. The CAE also promoted branching and fruiting in both chilli and tomato plants suggesting its possible utilization as biofertilizer for sustainable agriculture.