ANTIMICROBIAL ACTIVITY OF CHROMIUM CITRATE AND ITS EFFECT ON THE GROWTH OF LENTINULA EDODES

Abstract

The creation of a dietary food product by growing shiitake mushrooms (Lentinula edodes) on a wood substrate enriched with three-chromium is relevant and scientifically substantiated. The antimicrobial activity of chromium citrate is not known from the literature, but it can be assumed that it inhibits the growth of microorganisms and in certain concentrations can be toxic to Lentinula edodes. Therefore, the purpose of this work is to determine the antimicrobial activity of chromium citrate solutions of different concentrations (antibacterial and fungicidal) against test cultures and to study the effect of these solutions on the growth of L. Edodes fungi. Trivalent chromium citrate solution, shiitake mushroom mycelium (Lentinulaedodes 3790, Mycelia, Belgium), museum reference strains of pathogenic staphylococcus (Staphylococcusaureus ATCC 25923), Escherichia coli (Esherichiacoli ATCC 25922) and mold fungi (Aspergillusniger ATCC 16404), nutrient medium were used for research When determining the antimicrobial effect of a solution of chromium citrate at a concentration of 9.0 mg/l of chromium on test cultures of E. coli, S. aureus and A. niger, a bactericidal effect was established (100% for all tested strains). The bacteriostatic effect of the tested solutions of chromium citrate at a concentration of 6.0 mg/l was established for E. coli (72%), S.aureus (68%) and A. niger (62%). When studying the effect of chromium citrate solutions on E. coli ATCC 25922 in concentrations of 3.0 and 0.3 mg/l, it was established that the solutions did not exhibit antimicrobial properties, but, on the contrary, enhanced the growth of this culture. Chromium citrate solutions in the same concentrations (3.0 and 0.3 mg/l) did not show antimicrobial properties against the pathogenic strain of staphylococcus S.aureus ATCC 25923, and fungicidal activity against mold fungi A. niger ATCC 16404.Solutions with a high concentration of chromium (more than 9 mg/l) showed fungicidal activity and prevented the cultivation of shiitake mushrooms. Instead, solutions with a low chromium content (up to 3 mg/l) enhanced the growth of L. Edodes, acting as mycopromoters. It can be assumed that chromium in small amounts and in a bioavailable form is necessary for fungi to synthesize biologically active substances that stimulate their development. And chromium citrate in this case acts not as a disinfectant, but as a micro-fertilizer. So, chromium citrate solutions in concentrations up to 3.0 mg/l of chromium can be used in the cultivation of shiitake mushrooms (L. edodes) to increase the yield and enrich the mushrooms with chromium.