Characterization of the agroecological bio-input "Native Efficient Microorganisms" and evaluation of wheat germination.

BURGES, PABLO L.; HIRSCH, MAILÉN; VILLARREAL, NATALIA M.; MARINA, MARÍA

Los Cocos

Congreso; XVII Congreso Anual de la Asociación Civil de Microbiología General (SAMIGE).; 2022

As a useful tool within agroecology, producers make their biological inputs, starting with the raw material from their fields, obtaining a product that incorporates organic matter, minerals, and beneficial microorganisms in agricultural soils. Among them, the bio-input called “Native Efficient Microorganisms” (NEMs) is prepared in an artisanal way involving the capture of microorganisms from mountain or agricultural soils from pre-cooked rice, following a solid stage where it is mixed with the remaining vegetables and ends with a liquid stage where the activation of microorganisms is generated by anaerobic fermentation with the addition of milk, molasses, and water. The NEMs have beneficial effects on the soil and plants, increasing the microbiological diversity of the soil and functioning as plant growth promoters and biological control agents against phytopathogens. The objective of this work was to identify the cultivable heterotrophic bacteria found in this bio-input and to evaluate in vitro antagonistic capacities against Botrytis cinerea, as well as to evaluate the effect of NEMs on the germination of wheat seeds under laboratory conditions. As a result, an average of 2 x 108 UFC/ml was detected on the product. Thirteen isolated colonies showed phenotypic differences, which were confirmed by BOX-PCR. The sequencing and the subsequent bioinformatic analysis of 16S rRNA from isolated bacteria, allowed identifying the predominance of the Bacillus and Lactobacillus, which due to conditions generated during anaerobic fermentation could be inhibiting the growth of other microorganisms. Approximately fifty percent of the strains inhibit the in vitro growth of Botrytis cinerea. Some of them do it through volatile compounds that could be relevant during the foliar application of the product. In addition, we decided to study the effect of NEMs on wheat growth. We proved different concentrations of NEMs on wheat seeds. When we applied a concentration of 0.05 % (v/v) NEMS, higher speed of germination was observed in comparison to controls. Moreover, the application increased the radicle and coleoptile length, possibly allowing an increase in water absorption and seedling emergence. Our results showed that the NEMs bio-input is composed, at least in part, of bacteria of the Bacillus genus cited as agricultural soil predominant, acting as promoters of plant growth as well as bio controllers.