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

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 risk factors for fractures and trabecular bone-score value in patients with endogenous Cushing's syndrome.

In a cohort study of 182 consecutive patients with active endogenous Cushing's syndrome, the only predictor of fracture occurrence after adjustment for age, gender bone mineral density (BMD) and trabecular bone score (TBS) was 24-h urinary free cortisol (24hUFC) levels with a threshold of 1472 nmol/24 h (odds ratio, 3.00 (95% confidence interval (CI), 1.52-5.92); p = 0.002). INTRODUCTION: The aim was to estimate the risk factors for fracture in subjects with endogenous Cushing's syndrome (CS) and to evaluate the value of the TBS in these patients. METHODS: All enrolled patients with CS (n = 182) were interviewed in relation to low-traumatic fractures and underwent lateral X-ray imaging from T4 to L5. BMD measurements were performed using a DXA Prodigy device (GEHC Lunar, Madison, Wisconsin, USA). The TBS was derived retrospectively from existing BMD scans, blinded to clinical outcome, using TBS iNsight software v2.1 (Medimaps, Merignac, France). Urinary free cortisol (24hUFC) was measured by immunochemiluminescence assay (reference range, 60-413 nmol/24 h). RESULTS: Among enrolled patients with CS (149 females; 33 males; mean age, 37.8 years (95% confidence interval, 34.2-39.1); 24hUFC, 2370 nmol/24 h (2087-2632), fractures were confirmed in 81 (44.5%) patients, with 70 suffering from vertebral fractures, which were multiple in 53 cases; 24 patients reported non-vertebral fractures. The mean spine TBS was 1.207 (1.187-1.228), and TBS Z-score was -1.86 (-2.07 to -1.65); area under the curve (AUC) was used to predict fracture (mean spine TBS) = 0.548 (95% CI, 0.454-0.641)). In the final regression model, the only predictor of fracture occurrence was 24hUFC levels (p = 0.001), with an increase of 1.041 (95% CI, 1.019-1.063), calculated for every 100 nmol/24-h cortisol elevation (AUC (24hUFC) = 0.705 (95% CI, 0.629-0.782)). CONCLUSIONS: Young patients with CS have a low TBS. However, the only predictor of low traumatic fracture is the severity of the disease itself, indicated by high 24hUFC levels

Phase stability and elasticity of Sc 2O 3 at high pressure

An investigation into the high-pressure behavior of Sc2O3 was conducted using first-principle calculations based on density functional theory within the generalized gradient approximation. Nine candidate phases were considered and simulated, C-, B-, A-RES, Rh2O3(II), Gd2S3, U2S3, Al2Er3, corundum and PPv respectively. Our results demonstrate phase transitions of Sc2O3 from C- to B-RES phase at 15 GPa, then to Gd2S3 phase at 18 GPa. Elastic constants of Sc2O3 present softening from about 270 GPa to 337 GPa, associated with a semiconductor-to-metal crossover. The Gd2S3-type Sc2O3 is both mechanically and dynamical stable at least up to 302 GPa supported by the mechanically stable criteria and the phonon spectrum