Biodegradable capacities of fungal strains of Fusarium oxysporum (DSMZ 2018) and Fusarium culmorum (DSMZ 1094) were tested towards racemic mixture of chiral 2-hydroxy-2-(ethoxyphenylphosphinyl) acetic acid—a compound with two stereogenic centres. The effectiveness of decomposition was dependent on external factors such as temperature and time of the process. Optimal conditions of complete mineralization were established. Both Fusarium species were able to biodegrade every isomer of tested compound at 30°C, but F. culmorum required 10 days and F. oxysporum 11 days to accomplish the process, which was continuously monitored using the 31P NMR technique. 1. Introduction Organophosphonates are compounds characterized by the presence of a carbon atom covalently bound to a phosphorus atom. Such compounds are very stable and resistant to thermolysis, chemolysis, photolysis, and biochemical decomposition. [1] Phosphonic acids and their derivatives are molecules of interest due to their structural differentiation and great industrial importance. They are used as crop protection agents (weed control) in water treatment, in metal processing, and as flame-proofing agents [1]. The very valuable group of phosphonate derivatives are hydroxyphosphonates because they are known for their varied biological activities [2]. They act as enzyme inhibitors, antibacterial and antifungal factors, herbicides, antitumor or antiviral drugs, and mostly as molecules of defined absolute configuration. The use of such compounds applies in many consequences, mostly because of the extreme stability of mentioned P-C bond and the steric structure of the molecule. Increasing concentration of phosphonates derivatives in the environment has focused the attention of scientists on the problems with utilization of such pollutants. Biodegradation is a method of choice and represents undoubtedly an environmentally friendly solution. Some of the soil microorganisms have developed the capability to mineralize and biodegrade such molecules in order to acquire energy and nutrients [3–5]. The effectiveness of such degradation is dependent on several factors, including the chemical and steric structure of compounds and environmental conditions of the process. While bacterial degradation of phosphonic compounds has been thoroughly addressed and reviewed [3, 6], only few, recent works have focused on the use of fungal strains for degradation on such compounds [7–10]. This is interesting because there are advantages in using fungi for bioremediation as they possess extracellular enzymes and larger surface
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