IAA production and phosphate solubilization performed by native rhizobacteria in western Paraná

Abstract

In search for a more sustainable agriculture, the use of microorganisms as a technology is increasingly being used by agriculture throughout the world. This is due to the fact that it minimizes the use of agricultural supplies reducing environmental costs and impacts, based on the beneficial and natural relationships between edaphic organisms and cultivated plants. The rhizobacteria habitat in the soil establishes biochemical relationships with the plants acting as plant growth promoters (PGPR). Many of these bacteria are producers of phytohormones and enzymatic compounds with the capacity to provide important nutrients for plants. In this context, the present work aimed to quantify the potential of indole-3-acetic acid (IAA) production and the phosphate solubilization of rhizobacteria from Western Paraná. Isolates grown in DYGS medium plus tryptophan were quantified by colorimetry for the production of IAA. Iron phosphate solubilization was carried out by inoculation in modified Pikovskaya medium (PKV) and quantified by colorimetry. The results were evaluated by the Scott-Knott test at 5% using the SASM-Agri program. The highest IAA production was observed with the addition of tryptophan to Erwinia (219); Enterobacter (302) and Salmonella (57). Isolates Falsibacillus (438) and 505 showed higher efficiency in the iron phosphate solubilization. Isolates Enterobacter (130), 438 and Enterobacter (151) were highlighted in both tests, being characterized as a great potential for use in biotechnological products.