Biological Oxidation Process Research Articles

Mutations of methionine 444 interacting with T1Cu-coordinating amino acids affect the structure and function of multicopper oxidase CopA.

Manganese is an essential trace element for humans, animals, and plants, but excessive amounts of manganese can cause serious harm to organisms. The biological manganese oxidation process mainly oxidizes Mn(II) through the secretion of unique manganese oxidase by manganese-oxidizing bacteria. The T1 Cu site of multicopper oxidase is the main site for substrate oxidation, and its role is to transfer electrons to TNC, where dioxygen reduction occurs. In this study, methionine (Met) No. 444 interacting with the T1Cu-coordinating amino acid in the multicopper oxidase CopA from Brevibacillus panacihumi MK-8 was mutated to phenylalanine (Phe) and leucine (Leu) by the enzyme. Based on the analysis of enzymatic properties and the structural model, the mutant protein M444F with 4.58 times the catalytic efficiency of the original protein CopA and the mutant protein M444L with 1.67 times the catalytic efficiency of the original protein CopA were obtained. The study showed that the manganese removal rate of the manganese-oxidizing engineered bacterium Rosetta-pET-copAM444L cultured for 7 days was 88.87%, which was 10.77% higher than that of the original engineered bacterium. Overall, this study provides a possibility for the application of genetic engineering in the field of biological manganese removal.

Economics of enhanced methane oxidation relative to carbon dioxide removal

Mitigating short-term global warming is imperative, and a key strategy involves reducing atmospheric methane (CH4) due to its high radiative forcing and short lifespan. This objective can be achieved through methods such as oxidising methane at its source or implementing enhanced oxidation techniques to reduce atmospheric CH4 concentrations. In this study, we use a range of metrics to analyse both the impact and value of enhanced CH4 oxidation relative to carbon dioxide (CO2) removal on global temperature. We apply these metrics to a select group of model studies of thermal-catalytic, photocatalytic, biological and capture-based oxidation processes under different greenhouse gas (GHG) concentrations. Using a target cost of €220-1000/tCO2 for CO2 removal, our findings indicate that metrics valuing enhanced oxidation techniques based on their contribution to mitigating the long-term level of warming show these techniques are uncompetitive with CO2 removal. However, when using metrics that value enhanced oxidation of CH4 based on its impact on the immediate rate of warming, photocatalytic methods may be competitive with CO2 removal, whereas biofiltration, thermal-catalytic oxidation and capture-based units remain uncompetitive. We conclude that if the policy goal is to target the immediate rate of warming, it may be more valuable to incentivise CO2 removal and enhanced oxidation of methane under separate GHG targets.

Proteomic insights uncover enhanced neurotherapeutic potential in conditioned mesenchymal stem cell-derived extracellular vesicles

Extracellular vesicles (EVs) show more potential as therapeutic agents for treating neurological disorders than their parent cells like MSCs. Notably, the therapeutic efficacy of MSCs can be boosted by inflammation factors and oxidative stressors. Here, we investigated the impact of activated microglial cell supernatant (Con1) and hydrogen peroxide (Con2) on MSCs and collected their derived EVs, followed by using high-resolution mass spectrometry to analyze MSC-EV proteomic and phosphoproteomic profiles, and verified the indicated functional protein and phosphorylated kinase as well. Our findings showed that both Con1 and Con2 EVs exhibited characteristic features of extracellular vesicles and possessed greater anti-inflammatory and antioxidant activity compared to unconditioned MSC-EVs. Omics analysis revealed alterations in protein expression and phosphorylation associated with inflammation and oxidation biological processes and signaling pathways, as well as signified the post-translational modification of proteins in Con1/2 EVs. Importantly, we identified that the anti-inflammatory role of MSC-EVs was linked to the serine/threonine kinase phosphorylation, and inhibition of insulin-like growth factor 1 receptor (IGF1R) reduced the antioxidant activity of MSC-EVs. This report documented the changed protein expression and phosphorylated patterns of Con1/2 EVs, and provided insights into the functionalization mode of MSC-EVs, suggesting the enhanced neurotherapeutic potential of conditioned EVs in the treatment of neurological diseases.

Study of head and neck squamous cell carcinoma transcriptome after proton therapy

Aim. To evaluate changes in the transcriptome of head and neck squamous cell carcinoma (HNSCC) tissue cells in patients after proton therapy.Materials and methods. Biopsy material obtained from 3 HNSCC patients before and after proton therapy at a total dose of 10 isoGy was homogenized, purified, and concentrated. Then total RNA was isolated with further purification and concentration with the RNA Clean & Concentrator kit (Zymo Research). Library quantitation was assessed using the Qubit 2.0 instrument (Invitrogen, Life Technologies). After isolation of 1 μg total RNA for sequencing, libraries were prepared on the Illumina platform using the TruSeq RNA Sample Prep Kit v2 with a 10-cycle enrichment step according to the manufacturer’s recommendations. The quality of RNA and the resulting libraries was checked using the Agilent 2100 Bioanalyzer system (Agilent Tec. Inc., USA). The RIN parameter for RNA was at least 7. The library concentration was assessed by real-time PCR on the CFX96 Touch Real-Time PCR Detection System (Bio-Rad, USA). Final libraries were pooled in equimolar ratios before sequencing on the Illumina HiSeq 2500 platform using 50 base-pair paired-end reads. The Q20 parameter for all samples was > 97%, and the number of reads averaged 60.2 million per sample. Raw reads were processed using the RTA 1.17.21.3 and Casava 1.8.2 (Illumina). The enrichment analysis was performed using the PANTHER 17.0 software.Results. The transcriptome analysis of HNSCC after proton radiation therapy (5 x 2 isoGy) at a total dose of 10 isoGy revealed 1,414 significantly differentially expressed genes. The 10 most and least expressed genes and their associated signaling pathways were identified. A number of signaling pathways associated with the underexpressed genes were detected in HNSCC after proton therapy, such as: STAT5; PD-1 signaling pathway; marked MET-mediated activation of PTK2 signaling pathway, PDGF signaling; CD22-mediated regulation of BCR; and FCERI-mediated MAPK activation. In addition to the above signaling pathways, activation of collagen degradation, FCGR3A-mediated phagocytosis, and FCGR3A-mediated interleukin (IL)-10 synthesis are of interest. In the enrichment analysis among highly expressed genes, keratinization and biological oxidation processes were activated in HNSCC tissues after proton therapy.Conclusion. Proton therapy in HNSCC leads to overexpression of genes involved in the regulation of keratinization and biological oxidation processes as well as to underexpression of genes associated with suppression of signaling pathways: STAT5, PD-1, MET-mediated activation of PTK2 signaling pathway, PDGF signaling; CD22-mediated regulation of BCR; FCERI-mediated MAPK activation, collagen degradation, FCGR3A-mediated phagocytosis activation, and FCGR3A-mediated IL-10 synthesis. All signaling pathways of underexpressed genes function in HNSCC cells if there is no negative influence on the tumor from outside (irradiation or delivery of antitumor drugs). The predominance of suppressed signaling pathways over activated ones most likely indicates a decrease in the functional potential of cells after proton therapy. The dose-dependence of PT effects necessitates further study of changes in cellular and molecular-genetic signatures of HNSCC after proton irradiation with different doses.

Re-yellowing of chromium-contaminated soil after reduction-based remediation: Effects and mechanisms of extreme natural conditions

Chromium (VI) in soil poses a significant threat to the environment and human health. Despite efforts to remediate Cr contaminated soil (Cr-soil), instances of re-yellowing have been observed over time. To understand the causes of re-yellowing as well as the influence of overdosed chemical reductant in remediating Cr-soil, experiments on excess reducing agent interference and soil re-yellowing mechanisms under different extreme conditions were conducted. The results show that the USEPA method 3060A & 7196A combined with K2S2O8 oxidation is an effective approach to eliminate interference from excess FeSO4 reducing agents. The main causes of re-yellowing include the failure of reducing agents, disruption of soil lattice, and interactions between manganese oxides and microorganisms. Under various extreme conditions simulated across the four seasons, high temperature and drought significantly accelerated the failure of reducing agents, resulting in the poorest remediation effectiveness for Cr-soil (91.75 %). Dry-wet cycles promoted the formation of soil aggregates, negatively affecting Cr(VI) removal. While these extreme conditions caused relatively mild re-yellowing (9.46 %–16.79 %) due to minimal soil lattice damage, the potential risk of re-yellowing increases with the failure of reducing agents and the release of Cr(VI) within the lattice. Prolonged exposure to acid rain leaching and freeze-thaw cycles disrupted soil structure, leading to substantial leaching and reduction of insoluble Cr, resulting in optimal remediation effectiveness (94.37 %–97.73 %). As reducing agents gradually and the involvement of the water medium, significant re-yellowing occurred in the remediated soil (51.52 %). Mn(II) in soil enriched relevant microorganisms, and the Mn(IV)-mediated biological oxidation process was also one of the reasons for soil re-yellowing.

Кратък обзор върху микробиологични аспекти на компостирането

Recycling and disposal of urban waste is one of the goals set by the European Union. The process of composting, which is a cost-effective and environmentally friendly method of processing organic residues, is considered to be one of the ways to achieve these goals. Composting is a biological oxidation process in which organic residues are broken down by a large group of different microorganisms. The present publication presents a brief overview on the composting of organic residues and the participation of individual groups of microorganisms in this process. The decay of materials during composting follows the general biochemical pathways of any other degradation process. In the composting processes and in the finished compost, non-sporeforming bacteria and bacilli, which are most actively involved in the initial stages of degradation of organic substances, occupy a major share in the composition of the general microflora. The share of actinomycetes and micromycetes, which are generally more active in the final stages of organic matter decomposition, is smaller. The amount of actinomycetes increases with increasing temperature in the composting phases. The biogenicity of compost depends on the type of biodegradable agricultural waste used.

Dynamic Modelling, Process Control, and Monitoring of Selected Biological and Advanced Oxidation Processes for Wastewater Treatment: A Review of Recent Developments.

This review emphasizes the significance of formulating control strategies for biological and advanced oxidation process (AOP)-based wastewater treatment systems. The aim is to guarantee that the effluent quality continuously aligns with environmental regulations while operating costs are minimized. It highlights the significance of understanding the dynamic behaviour of the process in developing effective control schemes. The most common process control strategies in wastewater treatment plants (WWTPs) are explained and listed. It is emphasized that the proper control scheme should be selected based on the process dynamic behaviour and control goal. This study further discusses the challenges associated with the control of wastewater treatment processes, including inadequacies in developed models, the limitations of most control strategies to the simulation stage, the imperative requirement for real-time data, and the financial and technical intricacies associated with implementing advanced controller hardware. It is discussed that the necessity of the availability of real-time data to achieve reliable control can be achieved by implementing proper, accurate hardware sensors in suitable locations of the process or by developing and implementing soft sensors. This study recommends further investigation on available actuators and the criteria for choosing the most appropriate one to achieve robust and reliable control in WWTPs, especially for biological and AOP-based treatment approaches.

Small Scale Wastewater Treatment Method for Rainwater Garden Based on Photovoltaic Photocatalysis Technology

Conventional small-scale sewage treatment mostly adopts the principle of biological contact oxidation process, which has limited scope of application, low degradation rate of pollutants in sewage, and poor sewage treatment effect. Based on this, a new small-scale sewage treatment method was proposed by introducing photovoltaic photocatalysis technology and taking S sponge community in Ningnan County, Liangshan Prefecture as an example. First, hydrothermal method is used to prepare photocatalyst to provide basic guarantee for sewage treatment. Secondly, the rainwater garden model is simulated and designed to obtain the composition and content of small-scale sewage. On this basis, a rainwater garden photovoltaic photocatalytic water purification system is designed, which establishes an A/O integrated process by connecting the anoxic zone (A section) and aerobic zone (O section) in series to fully achieve the goal of sewage treatment. Experimental analysis shows that the new method can significantly improve the degradation rate of organic pollutants in rainwater garden wastewater, with a degradation rate of over 99% and a maximum degradation time of 10.97 seconds, indicating that the application effect of this method is good.

Combination of advanced biological systems and photocatalysis for the treatment of real hospital wastewater spiked with carbamazepine: A pilot-scale study

Over the past few decades, the increase in dependency on healthcare facilities has led to the generation of large quantities of hospital wastewater (HWW) rich in chemical oxygen demand (COD), total suspended solids (TSS), ammonia, recalcitrant pharmaceutically active compounds (PhACs), and other disease-causing microorganisms. Conventional treatment methods often cannot effectively remove the PhACs present in wastewater. Hence, hybrid processes comprising of biological treatment and advanced oxidation processes have been used recently to treat complex wastewater. The current study explores the performance of pilot-scale treatment of real HWW (3000 L/d) spiked with carbamazepine (CBZ) using combinations of moving and stationary bed bio-reactor-sedimentation tank (MBSST), aerated horizontal flow constructed wetland (AHFCW), and photocatalysis. The combination of MBSST and AHFCW could remove 85% COD, 93% TSS, 99% ammonia, and 30% CBZ. However, when the effluent of the AHFCW was subjected to photocatalysis, an enhanced CBZ removal of around 85% was observed. Furthermore, the intermediate products (IPs) formed after the photocatalysis was also less toxic than the IPs formed during the biological processes. The results of this study indicated that the developed pilot-scale treatment unit supplemented with photocatalysis could be used effectively to treat HWW.

SERS Tracking Oxidative Stress on a Metalloporphyrin Framework by Vitamin C.

Accurate control of charge transfer is crucial to investigate the catalytic reaction mechanism of the biological oxidation process that biomedicine participates in. Herein, we have established an assembly model of metalloporphyrin framework (MPF) nanosheets as the active centers of biological enzymes. The introduction of Vitamin C (VC) into the MPF system can precisely modulate its content of charges. The surface-enhanced Raman scattering activity and peroxidase-like catalytic performance are enhanced simultaneously for the first time by manipulating the optimal molar ratio of an MPF to VC and the reaction sequence with target model molecules. We have confirmed that the formation of the intermediate of Fe(2+)-OOH species is specifically enhanced after VC modulation, which indicates that VC can regulate the oxidative stress of the active center of biological enzymes. This discovery not only accurately resolves the mechanism of VC-selective anticancer therapy but also has important significance for the precise treatment of VC synergistic targeting medicines.

Effects of regular zooplankton supplement on the bacterial communities and process performance of biofilm for wastewater treatment

Biofilm processing technologies were widely used for wastewater treatment due to its advantages of low cost and easy management. However, the aging biofilms inevitably decrease the purification efficiency and increase the sludge production, which limited the widely application of biofilms technologies in rural area. In this study, we proposed a novel strategy by introducing high-trophic organisms to prey on low-trophic organisms, and reduce the aged biofilms and enhance treatment efficiencies in rural wastewater treatment. The effect of three typical zooplankton (Paramecium, Daphnia, and Rotifer) supplement on the purification efficiency and biofilm properties in the contact oxidation process were investigated, and the reaction conditions were optimized by an orthogonal experiment. Under optimal conditions, the biofilms weight decreased 67.6%, the oxygen consumption rate of biofilms increased 9.4%, and wastewater treatment efficiency was obviously increased after zooplankton supplement. Microbial sequencing results demonstrated that the zooplankton optimize the contact oxidation process by altering the bacterial genera mainly Diaphorobacter, Thermomonas, Alicycliphilus and Comamonas. This research provides insight into mechanism of the zooplankton supplement in biological contact oxidation process and provides a feasible strategy for improving the rural sewage treatment technology.

Distinguishing homogeneous advanced oxidation processes in bulk water from heterogeneous surface reactions in organic oxidation

Clarifying the reaction pathways at the solid-water interface and in bulk water solution is of great significance for the design of heterogeneous catalysts for selective oxidation of organic pollutants. However, achieving this goal is daunting because of the intricate interfacial reactions at the catalyst surface. Herein, we unravel the origin of the organic oxidation reactions with metal oxide catalysts, revealing that the radical-based advanced oxidation processes (AOPs) prevail in bulk water but not on the solid catalyst surfaces. We show that such differing reaction pathways widely exist in various chemical oxidation (e.g., high-valent Mn3+ and MnOX) and Fenton and Fenton-like catalytic oxidation (e.g., Fe2+ and FeOCl catalyzing H2O2, Co2+ and Co3O4 catalyzing persulfate) systems. Compared with the radical-based degradation and polymerization pathways of one-electron indirect AOP in homogeneous reactions, the heterogeneous catalysts provide unique surface properties to trigger surface-dependent coupling and polymerization pathways of a two-electron direct oxidative transfer process. These findings provide a fundamental understanding of catalytic organic oxidation processes at the solid-water interface, which could guide the design of heterogeneous nanocatalysts.

Photocatalytic Degradation of Toluene (Component of Crude Oil) Contaminated Water Using Titanium Dioxide Based Catalyst: A Review

Petroleum industry is one of the fastest growing industry in the world, and it contributes significantly to the profitable development in unindustrialized countries. The wastewater from a petroleum industry consist a wide variety of pollutants like petroleum hydrocarbons, mercaptans, oil and grease, benzene, toluene, ethylbenzene, xylene, phenol, ammonia, sulphide and other organic compounds etc. All these compounds are present as very complex form in discharged water of petroleum industry, which are harmful to the environment and human health directly or indirectly. Pollution of soil-water interface due to the release of hydrocarbons in environment is a major public health concern, and therefore, remediation of these pollutants is needed to reduce risk to human and environment. Various methods such as physical, chemical, biological, and Advanced oxidation processes (AOPs) methods are used to degrade these pollutants from wastewater. The conventional remediation methods can only change the phase of contaminants without destroying them, thereby leading to another pollution problem. This review paper highlights some current treatment methods of toluene contaminated water, and to introduce a proposed method that sought to develop an oleophilic and hydrophobic composite catalyst (ESA-TiO2-FeS2-Kenaf), that would harvest the toluene content, and simultaneously degrade the harvested toluene content using solar light as the energy source.

A critical review of textile industry wastewater: green technologies for the removal of indigo dyes.

The denim textile industry represents an important productive sector. It generates wastewater with low biodegradability due to the presence of persistent pollutants, which can produce toxic and carcinogenic compounds; therefore, wastewater treatment reduces risks to aquatic life and public health. This paper presents a review of 172 papers regarding textile industry wastewater treatment for the removal of contaminants, especially indigo dyes used in the denim industry, in the context of green technologies. The physicochemical characteristics of textile wastewater, its environmental and health impacts, and the permissible limit regulations in different countries were reviewed. Biological, physicochemical and advanced oxidation processes for the removal of indigo dyes were reviewed. The goal of this study was to analyze the characteristics of green technologies; however, the research does not clearly demonstrate an effect on energy consumption savings, carbon footprint decreases, and/or waste generation. Advanced oxidation processes showed the highest color removal efficiency (95 and 97% in synthetic or real wastewater, respectively). Photocatalysis and Fenton reactions were the most efficient processes. None of the revised works presented results regarding upscaling for industrial application, and the results should be discussed in terms of the guidelines and maximum permissible limits established by international legislation. New technologies need to be developed and evaluated in a sustainable context with real wastewater.

Single-Site SnOCu Pairs with Interfacial Electron Transfer Effect for Enhanced Electrochemical Catalysis and Sensing.

As advanced electrochemical catalysts, single-atom catalysts have made great progress in the field of catalysis and sensing due to their high atomic utilization efficiency and excellent catalytic performance. Herein, stannum-doped copper oxide (CuOSn1 ) nanosheets with single-site SnOCu pairs as active sites are synthesized as electrocatalysts for biological molecule detection. Compared with CuO-based electrochemical sensors, the CuOSn1 -based electrochemical sensors have improved detection sensitivity with a rapid electrochemical response. Theoretical calculation reveals that the single-site SnOCu pairs induced interfacial electronic transfer effect can strengthen hydroxy adsorption and thus reduce the energy barrier of the biological molecule oxidation process. As a concept application, electrochemical detection of dopamine and uric acid molecules is achieved, exhibiting satisfactory sensitivity and selectivity. This work demonstrates the advantages of single-site SnOCu pairs in electrochemical catalysis and sensing, which provides theoretical guidance for understanding the structure-activity relationship for sensitive electrochemical sensing.

Transformation of microplastics by oxidative water and wastewater treatment processes: A critical review.

Microplastics (MPs) are contaminants of emerging concern that accumulate in various environments, where they pose threats to both the ecosystem and public health. Since MPs have been detected in drinking water resources and wastewater effluents, more efficient treatment is needed at wastewater treatment plants (WWTPs) and drinking water treatment plants (DWTPs). This review discusses the potential of biological, photochemical, Fenton (-like) systems, ozonation, and other oxidation processes in the treatment of MPs in terms of their indicators of oxidation such as mass loss and surface oxidation. The oxidation processes were further analyzed in terms of limitations and environmental implications. Most previous studies examining MPs degradation using conventional treatments-such as UV disinfection, ozonation, and chlorination-employed significantly higher doses than the common doses applied in DWTPs and WWTPs. Owing to such dose gaps, the oxidative transformation of MPs observed in many previous studies are not likely to occur under practical conditions. Some novel oxidation processes showed promising MPs treatment efficiencies, while many of them have not yet been applied on a larger scale due to high costs and the lack of extensive basic research. Health and environmental impacts related to the discharge of oxidized MPs in effluents should be considered carefully in different aspects: the role as vectors of external pollutants, release of organic compounds (including organic byproducts from oxidation) and fragmentation into smaller particles as MPs circulate in the ecosystem as well as the possibility of bioaccumulation. Future research should also focus on ways to incorporate developed oxidation processes in DWTPs and WWTPs to mitigate MPs contamination.

Impact of biochar amendment on antibiotic removal and ARGs accumulation in constructed wetlands for low C/N wastewater treatment

Constructed wetlands (CWs) amended with biochar to stimulate antibiotic and antibiotic resistance genes (ARGs) removal from carbon restricts wastewater holds particular application prospect due to high efficiency and good stability. In this study, we conducted biochar amended constructed wetland (BCW) and non-biochar amended constructed wetland (NCW) to explore the feasibility and mechanisms for sulfamethoxazole (SMX) and ARGs removal from low C/N wastewater. Results showed that biochar-amended considerably stimulated the biological oxidation and reduction process in CW, as evidenced by higher chemical oxygen demand (COD), nitrogen, and SMX removal performance (7.1 ± 2.6 %, 19.8 ± 3.6 %, 36.8 ± 6.2 %) than that in NCW. The accumulation of ARGs was negatively associated with SMX removal efficiency, where the int and sul genes performed lower concentration in BCW due to the higher SMX removal efficiency. The biochar’s dissolved organic carbon release in CWs indicated that water and alkaline media portray the optimum conditions for SMX and ARGs removal. Microbial community analysis exposed that more functional consortia capable of SMX metabolism (e.g., Arthrobacter, Ramlibacter, Flavobacterium, and norank_f_JG30-KF-CM45) were enriched in BCW. This study demonstrated the feasibility and mechanism of biochar-amended CWs for regulated SMX removal and ARGs accumulation, which provides new insights for enhancing the depuration ability of CWs.

Reductive dehalogenation pathways and inhibition mechanisms of 2,5-dichloronitrobenzene in UV/sulfite advanced reduction process

2,5 − dichloronitrobenzene (2,5 − DCNB) and its chlorine − containing intermediates as adsorbable organic halogens (AOX), which may cause persist environment and health damages, are widely present in fine chemical wastewater. However, AOX in high − salt wastewater are hardly removed by biological process and advanced oxidation process (AOPs). Advanced reduction processes (ARPs), especially UV/sulfite process, have attracted increasing attention in past few years due to their powerful reduction potential to refractory contaminants. In this study, the kinetics, main inhibition mechanisms, and degradation pathways of 2,5 − DCNB in UV/sulfite process were studied. The apparent reaction rate (kobs) increasing from 0.0059 min−1 to 0.0628 min−1 with sulfite dosage increasing from 2.6 mM to 104.2 mM and from 0.0027 min−1 to 0.0659 min−1 with pH value increasing from 3 to 12. Relative quantitation method based on EPR was developed to prove the dominant role of hydrated electron (eaq−) in UV/sulfite ARPs. A new sulfite activating pathway in dark was discovered at lower pH, which partly inhibits the ARPs. The nonlinear increase of kobs with increasing sulfite dosage was attributed to UV scattering which is caused by density fluctuation. The inhibition of Cl− triggered by ●OH from H2O direct photolysis by UV at 185 nm from lower pressure mercury lamp. This inhibition is linearly depending on Cl− concentration. The multiple competitive inhibition of NO3− was discussed and the three pathways are “inner filter” effect, eaq− competition and oxidizing species generation. In addition, the reduction pathways of 2,5 − DCNB during UV/sulfite ARPs were predicted by intermediates identification and density functional theory (DFT) calculation. Cyclohexanol with lower toxicity was identified as final product of UV/sulfite process. This study revealed the capacity of UV/sulfite ARPs for direct dehalogenation on benzene ring and the application potential in industrial wastewater dehalogenation.

Bacteria in the biosynthesis of animal nutrition components for crews of autonomous transport systems

The International Space Station (ISS) is currently using a water electrolysis process to produce oxygen. The hydrogen produced as a by-product is removed overboard. Carbon dioxide from crew breathing, dissolved in the atmosphere of the station, are extracted and also removed outside the station, but NASA expects to use it and convert it by the physicochemical reaction Sabatier in methane and water. Water will be used for crew needs and electrolysis, and methane is also planned to be removed overboard. When these interrelated processes work, very important substances are lost: methane, carbon dioxide, and hydrogen. This situation can be remedied by including in the life support system (LSS) of the ATS closed biotechnological regeneration cycles operating in a waste-free mode and synergistically solving the problems of complex provision of the crew with oxygen, water, and, most importantly, food. The process of biological oxidation of methane by methanotrophs bacteria is observed in nature in the first link of the food chain of the world's ocean and has long been used in terrestrial conditions for the industrial production of animal biomass for food and feed purposes. The same can be said about the use of hydrogen bacteria, which use carbon dioxide as a carbon source, with hydrogen as their energy source. Tolerance of these cultures to common nutrient media and the same technological parameters of biosynthesis allows their joint cultivation to obtain animal ingredients for crew food. The proposed work is devoted to the study of alternative processes, integrated use of carbon dioxide, methane, and hydrogen in LSS ATS.

Heme Oxygenase/Carbon Monoxide Participates in the Regulation of Ganoderma lucidum Heat-Stress Response, Ganoderic Acid Biosynthesis, and Cell-Wall Integrity.

Carbon monoxide (CO), a product of organic oxidation processes, arises in vivo principally from the enzymatic reaction of heme oxygenase (HO, transcription gene named HMX1). HO/CO has been found to exert many salutary effects in multiple biological processes, including the stress response. However, whether HO/CO is involved in the regulation of the heat-stress (HS) response of Ganoderma lucidum (G. lucidum) is still poorly understood. In this paper, we reported that under heat stress, the HMX1 transcription level, HO enzyme activity, and CO content increased by 5.2-fold, 6.5-fold and 2-fold, respectively. HMX1 silenced strains showed a 12% increase in ganoderic acid (GA) content under HS as analyzed by HPLC. Furthermore, according to Western blot analysis of the protein phosphorylation levels, HMX1 attenuated the increase in phosphorylation levels of slt2, but the phosphorylation levels were prolonged over a 3 h HS time period. The chitin and glucan content in HMX1 silenced strains increased by 108% and 75%, respectively. In summary, these findings showed that the HO/CO system responds to heat stress and then regulates the HS-induced GA biosynthesis and the cell-wall integrity mediated by the Slt-MAPK phosphorylation level in G. lucidum.