Coordination compound of FE(III) as stimulator of exocellular lipase synthesis for the Rhizopus arrhizus CNMN FD 03 fungal strain

Abstract

In the present work, the biological effect of 2,6-diacetylpyridine-bis(picolinoylhydrazone)-bis(aqua)iron(III)-hydrate(1/2.5), with the formula [Fe(H2L)(H2O)2](NO3)3∙2.5H2O (where H2L represents 2,6-diacetylpyridine bis(picolinoylhydrazone)), has been described. This coordination compound is highly soluble in water, which ensures a practical use as a component of nutrient mediums. The nutrient medium for submerged cultivation of the fungal strain Rhizopus arrhizus CNMN FD 03 contains soybean meal, (NH4)2SO4, KH2PO4, water and stimulant ([Fe(H2L)(H2O)2](NO3)3∙2.5H2O) in the following quantitative ratio of the components (g): soy flour – 35.0, (NH4)2SO4 – 1.0, KH2PO4 – 5.0, [Fe(H2L)(H2O)2](NO3)3∙2.5H2O –

0.005…0.015, drinking water – up to 1 L. The addition of coordination compound [Fe(H2L)(H2O)2](NO3)3∙2.5H2O to the nutrient medium of Rhizopus arrhizus CNMN FD 03 fungal strain, in concentration of 5.0…15.0 mg/L increases biosynthesis of lipases with 17.4…82.7%, depending on the concentration and reduces the producer`s cycle of cultivation by 24 h. Thus, the highest values of lipase activity were found in the first day of growth, while in the control (without stimulator) the maxim of activity was revealed in the second day. The most effective concentration for enzyme production was 5.0 mg/L [1]. In conclusion, the coordination compound [Fe(H2L)(H2O)2](NO3)3∙2.5H2O can be used as biostimulator of exocellular lipase synthesis for the mycelial fungal strain Rhizopus arrhizus CNMN FD 03 for the development of biotechnologies to obtain lipolytic enzymes.