Streptomyces from rotten wheat straw endowed the high plant growth potential traits and agro-active compounds

Abstract

Abstract Wheat straw is a major lignocellulosic waste produced in agricultural processes and has been traditionally used as soil conditioners in the form of compost, a precursor for humus. Microorganisms play an important role in the conversion of organic waste into plant available nutrients. Thus, it is essential to isolate the potential microorganisms from rotten/decomposed agricultural waste like wheat straws and endowed the plant growth promotion (PGP) as well as antagonism behavior against phyto-pathogens. The current study was conducted to investigate the actinobacteria isolated from rotten wheat straw for PGP and antagonistic traits. Among the all isolates, three strains (UU07, UU11 and UU15) were screened and were found potential to plant growth promoting (PGP) traits (IAA, siderophore, phosphate solubilization, HCN, ammonia and AAC deaminase). Based on 16S rRNA gene sequencing, isolates were identified as Streptomyces rochei UU07, Streptomyces vinaceusdrappus UU11 and Streptomyces sp. UU15. Strain UU07 showed 6.0% tolerance to salt and grew well at pH 4.5–9.4, while UU11 and UU15 were moderately tolerant to salt and pH. They grew well at 28 °C but were unable to grown on temperature above 45 °C. Seedling assay and antagonism test of S. rochei UU07 revealed it as one of the best PGP strain and potential antagonist for Rhizoctonia solani. These results confirmed that rotten wheat straw can serve as a potential source for isolation of actinobacteria with PGP traits which could further be used as consortia for composting of different agriculture-waste and increase crop production.