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 Argentino de Microbiología Genereal; 2022

Sociedad Argentina de Microbiología General

As a useful tool within agroecology, producers make their biological inputs, starting with theraw material from their fields, obtaining a product that incorporates organic matter, minerals,and beneficial microorganisms in agricultural soils. Among them, the bio-input called “NativeEfficient Microorganisms” (NEMs) is prepared in an artisanal way involving the capture ofmicroorganisms from mountain or agricultural soils from pre-cooked rice, following a solidstage where it is mixed with the remaining vegetables and ends with a liquid stage where theactivation 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 themicrobiological diversity of the soil and functioning as plant growth promoters and biologicalcontrol agents against phytopathogens. The objective of this work was to identify thecultivable heterotrophic bacteria found in this bio-input and to evaluate in vitro antagonisticcapacities against Botrytis cinerea, as well as to evaluate the effect of NEMs on thegermination of wheat seeds under laboratory conditions. As a result, an average of 2 x 108UFC/ml was detected on the product. Thirteen isolated colonies showed phenotypicdifferences, which were confirmed by BOX-PCR. The sequencing and the subsequentbioinformatic analysis of 16S rRNA from isolated bacteria, allowed identifying thepredominance of the Bacillus and Lactobacillus, which due to conditions generated duringanaerobic fermentation could be inhibiting the growth of other microorganisms.Approximately fifty percent of the strains inhibit the in vitro growth of Botrytis cinerea. Someof them do it through volatile compounds that could be relevant during the foliar applicationof the product. In addition, we decided to study the effect of NEMs on wheat growth. Weproved different concentrations of NEMs on wheat seeds. When we applied a concentration of0.05 % (v/v) NEMS, higher speed of germination was observed in comparison to controls.Moreover, the application increased the radicle and coleoptile length, possibly allowing anincrease in water absorption and seedling emergence. Our results showed that the NEMs bioinput is composed, at least in part, of bacteria of the Bacillus genus cited as agricultural soilpredominant, acting as promoters of plant growth as well as bio controllers.