An Approach for the Control of Caenorhabditis elegans N2 via the Regulation of Growth Conditions and Pleurotus ostreatus Po4

Abstract

Food resources are essential for the survival and growth of the population. Soil phytopathogenic nematodes cause great damage to agricultural crops, endangering food supplies and resources in general. Different methods have been used to control them. However, this issue still requires a more effective solution. Caenorhabditis elegans (CGC strain wild-type N2) was applied as a model with an Escherichia coli OP50 feeding substrate for nematodes. Our approach was based on the thermodynamically substantiated creation of growth conditions that are unfavorable for nematodes to suppress them irreversibly. The thermodynamic calculations showed that obligate anaerobic conditions, namely the absence of oxygen and a low redox potential (−100 mV and below), were potentially unacceptable for nematodes. Anaerobic conditions were created using both abiogenic (physicochemical) and biological methods. Abiogenic anaerobic conditions were achieved by preventing oxygen access and adding low-potential sodium sulfide (Eh = −250...−200 mV) to the cultivation medium. By applying biological methods, Pleurotus ostreatus Po4 and E. coli O2 was completely removed and the redox potential was decreased from +100…+200 mV to −100...−200 mV (in particular, due to the synthesis of H2S). Even the short-term exposure (1–2 days) of nematodes under anaerobic conditions led to their suppression and death. Thus, the short-term creation of anaerobic conditions in the soil may be an effective method to control, e.g., phytopathogenic aerobic nematodes. This research contributes to the development of foundations to preserve agricultural plants and increase crop yield as well as the development of an approach for the environmentally friendly control of phytopathogens.