Microorganisms Resistant to White Phosphorus

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. A

Evaluation of Potential Genotoxicity of New Furanone Derivatives – QS Inhibitors

Quorum sensing (QS) is a regulatory mechanism by which bacteria coordinate the expression of certain genes in response to their population density by producing, releasing and detecting small signal molecules. The discovery that QS regulates bacterial virulence and biofilm formation opens up new ways to control certain bacterial infections. The recent studies reported that synthetic halogenated furanones are capable of inhibiting bacterial QS and exhibited favorable therapeutic effects. New halogenated furanone derivatives have been tested for their ability to inhibit QS system. Three compounds having QS inhibitory activity have been identified among the synthesized compounds. The selected compounds have been also tested for the presence of genotoxicity using the Ames test and SOS-lux test. None of the compounds have shown any mutagenic activity in the bacterial test systems

Ecological and toxicological assessment of bioremediation of oil-contaminated soil

© 2020 Publishing House "O- Kratkoe". All rights reserved. Under the conditions of the growing season, the monitoring of gray forest soil was carried out, which was polluted with Devonian oil at a concentration of 5% and 10% by weight of the soil. The content of oil products, the amount of hydrocarbon-oxidizing microorganisms, and phytotoxicity were determined. For remediation, a natural consortium of microorganisms-destructors (CMD) was used, consisting of three strains (Achromobacter insolitus A-102 (RCAM02108), A. xylosoxidans A-10 (RCAM02109) and Pseudomonas stutzeri P-1026 (RCAM02107) with titer (2.3-2.5). 1012CFU/cm3, as well as bentonite in the native (6 and 12 ton/ha) and nanoscale (0.6 and 1.2 ton/ha) forms as a sorbent. When comparing the indicators of hydrocarbon content in the dynamics, it was found that a high percentage of their utilization was noted for 45 days when used separately CMD and bentonite. The use of nanobentonite, as well as the integrated application of CMD with sorbents in native and nanoscale forms, accelerate this process by 15 days. The trend observed at 5% oil pollution is maintained with an increase in pollution to 10%. Ecological and toxicological analysis of oil-contaminated soil on the morphometric parameters of the test plant (Zea mays) allowed us to build a series of effectiveness of the introduced components: CMD > CMD + nanobentonite > CMD + bentonite. Bentonite and nanobentonite, sorbing hydrocarbons, are a source of mineral nutrition for autochthonous microflora. Nanobentonite at a dose less than 10 times contributes to an increase in the efficiency of cleaning contaminated soil compared to bentonite. The combined use of CMD and sorbent in native and nanoscale forms allows us to ensure the rate of destruction of oil pollution at a higher level compared to using each component separately

Biological Degradation of Yellow (White) Phosphorus, a Compound of First Class Hazard

Abstract: 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

Effect of White Phosphorus on the Survival, Cellular Morphology, and Proteome of Aspergillus niger

© 2020, Pleiades Publishing, Inc. Abstract: 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