Microorganisms in spent water-miscible metalworking fluids as a resource of strains for their disposal

Metalworking fluids (MWFs) are essential components for modern metalworking technologies. The volume of world consumption of diluted working solutions exceeds 20 million tons annually. Water miscible MWFs accounts to 90% of the global MWFs demand. Spent MWFs contain toxic xenobiotics and residues of biocides. They are hazardous to the environment and require complex processing and detoxification. Microorganisms are able to colonize MWFs and metabolize the majority of available substances (oils and additives). Microbial degradation is one of the most efficient ways to dispose of water-miscible MWFs. The species composition of microorganisms changes during the operation of the fluid. From the point of view of the selection of effective biodegradion agents, the composition of microorganism species at the end of the MWFs service life cycle is of high interest for the industry. The aim of this work is to study the fungal and bacterial diversity of the microbiota of the spent MWF both by the method of isolating axenic cultures of fungi and bacteria, and by NGS-based metagenomic profiling using 16S rRNA for bacteria and ITS for fungi, and evaluate the possibility of their growth in diluted to a working concentration MWFs that differ in composition. Multiplex sequencing revealed (share in the samples more than 0.01%) 18 bacterial genera: Achromobacter, Alcaligenes, Aquamicrobium, Bacillus, Bacteroides, Brevundimonas, Caulobacter, Chryseobacterium, Dechlorobacter, Desulfovibrio, Dysgonomonas, Ochrobactrum, Proteiniphilum, Pseudomonas, Ralstonia, Shewanella, Sphingomonas, Stenotrophomonas and 17 fungal genera: Alternaria, Aspergillus, Bjerkandera, Cadophora, Candida, Cladosporium, Cryptococcus, Cystobasidium, Didymella, Fusarium, Malassezia, Penicillum, Pithomyces, Saccharomyces, Talaromyces, Wickerhamomyces, Yarrowia. Six genera of fungi (Saccharomyces, Fusarium, Malassezia, Bjerkandera, Penicillum, Alternaria) were identified in all tested samples. Yarrowia, Saccharomyces, Cadophora and Fusarium dominated in different samples. The diversity of bacterial biota was significantly higher than that of fungi. There was no clear dominance of any kind of bacteria in any sample. The analysis of isolated axenic cultures revealed that bacteria Shewanella putrefaciens, Proteus sp., Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Aeromonas hydrophila, Pseudomonas pseudoalcaligenes and fungi Fusarium solani, F. oxysporum, Yarrowia lipolytica, Candida metapsilosis were capable of growing in water-miscible MWFs. The data on the microorganism's species composition of the spent MWFs will make it possible to select species-specific DNA regions and design specific and sensitive test systems that can be used for identifying and evaluating the concentration of potential agents for the biodegradation of MWFs intended for disposal. © 2022 Elsevier Lt

DISTRIBUTION OF THIABENDAZOLE RESISTANT HELMINTHOSPORIUM SOLANI STRAIN

Helminthosporium solani strains were isolated from potato tubers that were grown in Russia, Germany and the Netherlands. Thiabendazole was effective against the sensitive strains of H. solani (EC50< 7.3 mg/l); however, 8 studied strains from Russia and the Netherlands were found to be extremely resistant to it (EC50 > 1000 mg/l). The sequence of their β-tubulin gene contained a SNP mutation in 198 codon or 200 codon, translating to Gln (CAG) instead of Glu (GAG) or Tyr (TAC) instead of Phe (TTC), respectively. Resistant to thiabendazole strains were found in distant regions of Russia (Moscow, Kostroma, Kaluga district) and in the Netherlands. Resistance to thiabendazole of the Russian, European, and American strains had the same genetic background and was conferred by the same mutations

Development of a Rapid Method for Monitoring Biodeterioration of Petroleum Products and Technical Fluids. Part I.

Abstract: Principles of a rapid method for monitoring biodeterioration of technicalfluids were developed with metalworking fluids as examples. Physicochemical andoperation properties of spent metalworking fluids were considered. The loss ofthe biological resistance of metalworking fluids leads to irreversible changesin the physicochemical and operation properties. A bank of test microorganismsrequired for validating the rapid method for monitoring biodeterioration wascompiled. © 2021, Pleiades Publishing, Ltd

The occurrence of thiabendazole-resistant isolates of Helminthosporium solani on potato seed tubers in Russia

Silver scurf is a potato tuber disease caused by Helminthosporium solani, which has become an increasing problem in many regions of Russia. The fungicide thiabendazole is widely used to control silver scab. Its target of action is the beta-tubulin gene. Single nucleotide mutations in this gene lead to a multiple increase in the resistance of the strain to the fungicide. The resistance of 37 Helminthosporium solani strains to the fungicide thiabendazole was tested in vitro. Tested strains were isolated from potato tubers grown in seven regions of Russia. In this study, the presence of thiabendazole-resistant strains was shown in populations of the European part of Russia, but not for the Far Eastern part. In the Far Eastern part, potatoes are grown from seeds of local production and there is practically no exchange with the European part of Russia. In the present study, we obtain sequences of the beta-tubulin gene and tested the resistance of strains affecting potatoes in the Far Eastern part of Russia to thiabendazole to show the absence of resistant strains. © 2020, Deutsche Phytomedizinische Gesellschaft

Surface Ozone Concentration over Russian Territory in the First Half of 2020

Abstract: Information on the ozone concentration in the surface air and troposphere in the first half of 2020 is presented. The data were acquired at 13 stations in different Russian regions; vertical distributions were obtained with the use of an aircraft laboratory. The excess over the Russian Federation hygienic standards is assessed; the daily average ozone concentration is found to be regularly higher the maximum permissible concentrations at most stations. At some stations, there are features the seasonal variations in the ozone concentration in the period under study different from previous years. © 2020, Pleiades Publishing, Ltd

Surface Ozone Concentration in Russia in the Second Half of 2020

Abstract: We present information on ozone concentration in the surface air layer in the second half of 2020. Data were obtained at 13 stations located in different regions of Russia. We estimated the excess over hygienic standards of the Russian Federation, both in the second half of the year and throughout 2020. It is shown that the daily average maximum permissible concentration of ozone is regularly exceeded at all stations. There are cases of exceeding the one-time maximum permissible concentration. © 2021, Pleiades Publishing, Ltd

Tropospheric Ozone Concentration on the Territory of Russia in 2021

Ozone is one of the most toxic admixtures in the troposphere. Therefore, it is among the main pollutants and its concentration is monitored. This work represents an overview of continuous measurements of the ozone content in the troposphere on the territory of Russia throughout 2021 carried out on an initiative of scientific and educational institutions at 17 stations in different Russian regions. The monitoring results showed that the daily average ozone concentration exceeded the MPCd.a level during a major part of the year at all observation sites, and by a factor of two or even three at a number of stations. At six stations, concentrations in excess of the maximum permissible one-time concentration MPCm.o were recorded. This requires a more comprehensive analysis of the composition and concentration of ozone precurcors and the development of measures to reduce their emission into the atmosphere. </jats:sec

Erratum to: Tropospheric Ozone Concentration on the Territory of Russia in 2021

An Erratum to this paper has been published: https://doi.org/10.1134/S102485602333001