The present work shows the first quantitative data on the biodegradation of red phosphorus by Aspergillus niger F-4815D. These data indicate a significant increase in the rate of red phosphorus oxidation, expressed through the accumulation of phosphate ions, the final product of oxidation, under the influence of the metabolism of Aspergillus growing in culture medium. Compared with the control, sterile medium containing red phosphorus, the rate increases by a factor of 1,25.

The biodegradation of oils by the strain Aspergillus niger AM1 VKM F-4815D was studied. Visual observation and gas chromatography-mass spectrometry showed that oil is subject to partial destruction, but cannot serve as the only source of carbon — the culture medium must contain glucose. An interesting fact is the change in consistency and hardening of oil under the influence of A. niger. This allows us to consider the possibility of using the strain for the bioremediation of soils and waters contaminated with oil. No less interesting is that, even earlier, the ability of the strain to metabolize a number of toxic phosphorus compounds, including even white and red phosphorus, was established. However, most organic solvents have a noticeable toxic effect, inhibiting growth in the presence of glucose and not becoming carbon sources in the absence of glucose.

For fourteen years our team has been working on the research of biodegradation, primarily of phosphorus-containing compounds. The world's first biological detoxification of elemental — white and red — phosphorus was carried out. We obtained mold fungi cultures, which transform a substance of the first hazard class white phosphorus into harmless phosphate. This is the first example of the inclusion of white phosphorus into the biospheric cycle of the phosphorus element. In the future, the results of the research may become the basis for effective methods of preventing and eliminating pollution by toxic phosphorus compounds. Therefore, the research is of interest both for practical application and from the point of view of fundamental science.

Для того, чтобы подтвердить родство с известными солюбилизаторами фосфатов, мы исследовали способность Aspergillus niger АМ1 метаболизировать ортофосфат кальция – наиболее расространенную форму фосфора в природе, но при этом малодоступную для живых организмов. Установлено, что штамм потребляет нерастворимый фосфат так же легко, как растворимые фосфаты, входящие в состав культуральных сред. То есть, действительно является солюбилизатором фосфата, как следует из анализа базы National Center for Biotechnology Information (NCBI). Возможно, именно эволюционная адаптация к нехватке доступного фосфора стала причиной способности микроорганизма потреблять целый ряд биологически недоступных форм данного элемента. На алкилборатах гриб растет только в присутствии глюкозы, а полиаспарагиновая кислота не оказывает на него токсическое действие. Также, A. niger АМ1 при росте на глюкозе вырабатывает этанол. In order to confirm their kinship with known phosphate solubilizers, we analyzed the ability of Aspergillus niger AM1 to metabolize calcium orthophosphate, the most abundant form of phosphorus in nature, yet inaccessible to living organisms. Interestingly,the strain consumed insoluble phosphate as easily as soluble phosphates in culture media, thus confirming the of the National Center for Biotechnology Information (NCBI) database analysis. Possibly, the evolutionary adaptation to the shortage of available phosphorus caused the ability of the microorganism to consume a number of biologically inaccessible forms of this element. The fungus grows on alkylborates only in the presence of glucose, and polyaspartic acid has no toxic effect on it. Additionally, A. niger AM1 produces ethanol when growing on glucose.

There is a possibility of using agricultural waste, in particular weeds, in innovative technologies for the restoration of disturbed land in order to increase fertility. Digestate, after anaerobic digestion of manure and weed plant Amaranthus retroflexus L. (AR), as well as solid carbonaceous residue after pyrolysis of AR. The combination of digestate, which contains high concentrations of total nitrogen, phosphorus, potassium, and solid carbonaceous residue, provides a new composite soil amendment. It has high potential as a source of nutrients because it contains a large amount of mineral components. The soil amendment does not contain toxic elements such as: lead, cadmium, mercury, arsenic and nickel, but the zinc and copper content exceeds the recommended values.

Microorganisms are known for their ability to adapt easily to any environment, forming specific ecosystems capable of surviving in harsh media. White phosphorus is one of the most dangerous and toxic pollutants, whose widespread use for various industrial and military purposes creates conditions for environmental pollution. It has previously been shown that some microbial cultures can adapt to the presence of white phosphorus in the environment, oxidizing it to a phosphate and then using it as a source of biogenic macronutrients. In prior studies, we have demonstrated the possibility of white phosphorus biodegradation by the fungal strains of Aspergillus niger . However, it is important to study the resistance of this species to such a toxic substance as white phosphorus. There may be several probable mechanisms, including the following: the cell wall of the fungus is a barrier to the penetration of white phosphorus into the cell, in which case an increase in the thickness of the cell wall should be observed in response to the impact of the toxicant; a mechanism associated with the expression of stress genes and the production of proteins involved in the disposal of toxins, including white phosphorus. In addition, white phosphorus causes an overall activation of metabolism, accompanied by an increase in the number and size of mitochondria in the cells. It is likely that the active forms of oxygen produced by mitochondria are involved in the detoxification of both white phosphorus and its transformation products. Microscopic and proteomic studies have confirmed the presence of the above-mentioned resistance mechanisms.

Biodegradation is an important method for the purification of industrial sewage and environment from chemical wastes. The biodegradation of elemental yellow (white) phosphorus was observed only in our studies. It is one of the most hazardous contaminants of environment. White phosphorus and its transformation products are used in industry, agriculture, drug manufacture, and military. For the first time, we have obtained cultures of microorganisms growing in media containing white phosphorus in concentration much higher than the threshold limit concentration in sewage. Elemental phosphorus is the strongest poison as reduced compounds and phosphate esters. However, in completely oxidized state (inorganic phosphates) it is a biogenic element necessary for all forms of life. Earth biomass consists of phosphorus almost by 3%. Prospects of the biodegradation of toxic phosphorus compounds, and elemental phosphorus are huge. The practical implementation of new deactivation method showing a number of advantages will allow one to reduce considerably fines imposed on plants producing and consuming yellow phosphorus.

The genotoxicity of white phosphorus was previously evaluated using the Ames test, which demonstrated the absence of toxicity. However, with all the advantages of this method, the use of the Ames test has some shortfallsin assessing genotoxicity. For this purpose, a series of supplementary tests wereconducted, including the SOS-lux test for DNA damaging activity. In the present work,the SOS-lux test confirmed the genotoxicity of white phosphorus. Based on a review of the literature, our results denote a first report on the genotoxic properties of white phosphorus. Allium test showed the mitotoxic effect of white phosphorus on eukaryotic cells.

Copper sulphate has no effect on the growth of aspergill in a media with white phosphorus. We compared the white phosphorus resistance of A. niger AM1 with three strains from the All-Russian Collection of Microorganisms. Highest resistance was observed in AM1.

We present preliminary results on the successful culturing of different microbial taxonomic groups on media containing white phosphorus (P4) as the sole source of phosphorus. The increase in culture resistance resulting from targeted selection was demonstrated. The highest concentration of P4 used in the study exceeds the threshold limit concentration of P4 in wastewater mud by 5000 times. Putative metabolites of P4 were also investigated. Keywords: biodegradation; white phosphorus; Aspergillus niger; Streptomyces sp. A8

В представленном исследовании сравнивался рост аспергилла АМ1 в культуральных средах, различающихся по составу, но в качестве источника фосфора содержащих белый фосфор. Сравнивая составы сред и скорость роста в них аспергилла, мы нашли ключевой компонент, который является благоприятным фактором для роста АМ1 и биодеградации белого фосфора. Этим компонентом оказался нитрат натрия NaNO3. Также, показано, что сульфат меди CuSO4 не оказывает никакого влияния на рост аспергиллов в средах с белым фосфором, независимо от состава этих сред. The presented study compared the growth of Aspergillus niger strain AM1 in culture media varying in composition but containing P4 as the sole source of phosphorus. Comparing the compositions of the media and the growth rate of Aspergillus in them, we found a key component that is a favorable factor for the growth of AM1 and the biodegradation of white phosphorus. This component was sodium nitrate (NaNO3). It has also been shown that copper sulphate (CuSO4) has no effect on the growth of Aspergillus in media with white phosphorus, regardless of the composition of these media.

In the present study, the mechanisms of Aspergillus niger AM1 and AM2 resistance to white phosphorus were studied. It was shown that the presence of white phosphorus (P4) at a concentration of 0.25% in the medium had a marginal impact on the ratio of living to dead cells during fungal cultivation, which indicates a high resistance of the strains to P4. Observations made with electron microscopy showed an increase in the thickness of the fungal cell wall, which is a barrier to the penetration of white phosphorus. MALDI results revealed the biosynthesis of new protein enzymes that could potentially participate in the neutralization of white phosphorus. In addition, white phosphorus caused activation of the metabolism, accompanied by an increase in the number of mitochondria in the cells.

White phosphorus is one of the most dangerous environmental pollutants. However, it is used in industry and for military purposes; therefore, it is impossible to overlook the fact that this substance is constantly released into the environment. In our works, cultures of microorganisms growing in media with a content of white phosphorus up to 1% were obtained for the first time. This exceeds the TLV in wastewater by 5000 times! These cultures are unique. For the first time, cultures were grown in media containing white phosphorus as the sole source of phosphorus. In these environments, microorganisms grew without experiencing phosphorus starvation. That is, they oxidized white phosphorus to phosphate, which is necessary for vital activity! This is first ever example of the inclusion of white phosphorus in the biospheric circulation of the phosphorus element.