METHODOLOGICAL INSTRUCTIONS “METHODOLOGY FOR IN VITRO SCREENING OF STRAINS, ISOLATES OF BACTERIA WITH PARASITIC AND NONMATICIDAL PROPERTIES”
The aim of this work was to develop a sequence for in vitro screening of isolates and strains of bacteria with similar activity on nematodes of various ecological groups, respectively, differing in the degree of cuticle permeability and having a different structure of the stoma, which is fundamental for the penetration of bacterial spores and toxins. The objects of screening were the saprobic nematode Caenorhabditis elegans, vinegar eel (Turbatrix aceti), mycohelminths Aphelenchus avenae, Aphelenchoides saprophilus, Paraphelenchus, migrating phytohelminths Ditylenchus destructor, larvae of gall nematodes of the genus Meloidyne. The proposed screening scheme makes it possible to comprehensively assess the effect of various strains and isolates on nematodes of various ecological groups. Strains, bacterial isolates that cause immobilization or death of nematodes, are reevaluated in vitro for other nematode species. In the case when the maximum mortality is observed in the variant with the undiluted isolate suspension, and when the suspension is diluted from minimum to maximum, there is a decrease in mortality to a minimum or does not differ statistically from the control, then a nematicidal effect of the metabolite products of the tested bacteria can be assumed. With a well-organized microbiological part, this algorithm can provide significant material for identifying bacteria with the desired properties, which in the future could serve as the basis for creating new drugs for protecting plants from nematodes and other pathogenic organisms.