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Acidophiles comprise a group of microorganisms adapted to live in acidic environments. Despite acidophiles are usually associated with an autotrophic metabolism, more than 80 microorganisms capable of utilizing organic matter have been isolated from natural and man-made environments. The ability to reduce soluble and insoluble iron compounds has been described for many of these species and may be harnessed to develop new or improved mining processes when oxidative bioleaching is ineffective. Similarly, as these microorganisms grow in highly acidic media and the chances of contamination are reduced by the low pH, they may be employed to implement robust fermentation processes. By conducting an extensive literature review, this work presents an updated view of basic aspects and technological applications in biomining, bioremediation, fermentation processes aimed at biopolymers production, microbial electrochemical systems, and the potential use of extremozymes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Indoor air pollution is a growing problem worldwide that causes a series of health issues in the population. Effective devices for abatement of volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) are currently restricted to adsorption systems based on active carbon. The objective of this study was to evaluate the operation of a new design of radial‐flow biopurifier using a model mixture of toluene, benzo(α)pyrene (BaP) and formaldehyde, initially inoculated with the filamentous fungus Fusarium solani and the bacterium Rhodococcus erythropolis. RESULTS: The results show that, under the range of inlet load tested and under continuous operation, the biopurification system achieved removal efficiencies above 90%, translating into a purifier air refreshment capacity of 0.62, 2.5 and 0.8 h−1 for BaP, formaldehyde and toluene, respectively. CONCLUSION: The system was operated for 8 months, without a decrease in the single‐pass removal efficiency, and withstood up to 15 days starvation periods with a marginal effect on its air refreshment capacity once the feeding of pollutants was restarted. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

BACKGROUND Alkylpyrazines are odorous compounds conferring pleasant aromas to baked and roasted foods. However, they are also emitted during food processing, creating a nuisance for the operators and the community. Only a few bacterial isolates have been shown to degrade 2,5‐methylpyrazine (DMP), as a model alkylpyrazine. This work aimed to study the ability of DMP biodegradation by the filamentous fungus Fusarium solani. RESULTS: Evidence of the degradation of DMP was collected in axenic cultures of F. solani in liquid mineral medium and over a saturated solid support using DMP as the sole carbon and energy source. DMP was used for growth as evidenced by the formation of an abundant aerial mycelium over a solid support, accompanied by the production of 70 ppm CO2 mg−1 dry biomass, and by its consumption in liquid media at a rate of 58.3 mg g−1 biomass h−1, a value comparable to those reported for bacteria. A non‐axenic biofilter was mounted, fed with a DMP‐laden air stream, and operated for 40 days. The maximum DMP elimination capacity achieved was 8.5 g m−3 h−1 at an inlet load of 11.3 g m−3 h−1 (an 80% relative efficiency). CONCLUSION: Fusarium solani uses DMP as a carbon source, showing great potential for its abatement in a biofilter. High‐throughput DNA sequencing of biofilter samples showed that it was the most representative member of the community, with a relative abundance surpassing 97%, indicating that it played a pivotal role in the biofilter. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Abstract A set of Cu/Ce/TiO 2 -SiO 2 and K/Cu/Ce/TiO 2 -SiO 2 catalysts was used for the simultaneous use of CO and naphthalene as reducing agents for the reduction of NO in the presence of oxygen. Only 5% of TiO 2 greatly increase the activity of the catalysts. It was also found that the addition of potassium is able to tune down these oxidation reactions allowing the reduction of NO. The Cu/Ce/TiO 2 -SiO 2 catalyst achieves the full conversion of naphthalene at 302 °C, 96% of CO conversion at the same temperature, and negligible conversion of NO. On the other hand, the K/Cu/Ce/TiO 2 -SiO 2 catalyst reaches the full conversion of CO at 330 °C, 90% conversion of NO at 342 °C, and 70% conversion of naphthalene at the latter temperature. Graphical abstract Image Highlights • CO and naphthalene can be used simultaneously to reduce NO in the presence of oxygen. • Full conversion of CO and naphthalene are at 330 °C and 400 °C, respectively. • A maximum 90% conversion of NO is achieved at 342 °C. [ABSTRACT FROM AUTHOR]

The gas-liquid mass transfer coefficient is a key parameter to the design and operation of biotrickling filters that governs the transport rate of contaminants and oxygen from the gas phase to the liquid phase, where pollutant biodegradation occurs. Mass transfer coefficients are typically estimated via experimental procedures to produce empirical correlations, which are only valid for the bioreactor configuration and range of operational conditions under investigation. In this work, a new method for the estimation of the gas-liquid mass transfer coefficient in biotrickling filters is presented. This novel methodology couples a realistic description of the packing media (polyurethane foam without a biofilm) obtained using microtomography with computational fluid dynamics. The two-dimensional analysis reported in this study allowed capturing the mechanisms of the complex processes involved in the creeping porous air and water flow in the presence of capillary effects in biotrickling filters. Model predictions matched the experimental mass transfer coefficients (±30%) under a wide range of operational conditions.