Environmental Microorganisms Research Articles

The Potential of Micro-Dictum Preparation in Surface Water Reclamation Subject to Strong Anthropogenic Pressure

The aim of this research was to analyze the potential of e micro-dictum preparation containing compositions of beneficial microorganisms using this product in surface water reclamation. The experiments were carried out in 2016. The scope of this research included the analysis of the physical and chemical properties of a solid preparation; tests of the microbiological parameters of micro-dictum; an analysis of the spread of microorganisms in the aquatic environment; a study of water quality with the solid preparation; and tests of the formulation in real conditions and its potential in the reclamation of surface waters. Tests on the produced formulation were carried out in the laboratory in containers and under real conditions. Laboratory tests have shown that the analyzed preparation may introduce certain amounts of nitrogen and phosphorus into the water. However, they are not important in the case of water reclamation. Analyses of the micro-dictum preparation showed that the content of lactic acid bacteria in the center of the ball is lower compared to the outer layers. The results describing an increase in the number of lactic acid bacteria correlate with a decrease in pH and oxygen dissolved in the water with the preparation. The tests showed no negative impact on changes in the physical and chemical properties of water at the site of application. Changes in physical parameters were recorded, in particular dissolved oxygen and pH at the bottom, where the greatest microbiological activity occurred.

Microbial Life in Playa-Lake Sediments: Adapted Structure, Plastic Function to Extreme Water Activity Variations

Saline shallow lakes in arid and semi-arid regions frequently undergo drying episodes, leading to significant variations in salinity and water availability. Research on the impacts of salinity and drought on the structure and function of biofilms in hypersaline shallow lakes is limited. This study aimed to understand the potential changes of biofilms in playa-lake sediments during the drying process. Sediments were sampled at different depths (surface, subsurface) and hydrological periods (wet, retraction, and dry), which included a decrease in water activity (aw, the availability of water for microbial use) from 0.99 to 0.72. aw reduction caused a greater effect on functional variables compared to structural variables, indicating the high resistance of the studied biofilms to changes in salinity and water availability. Respiration and hydrolytic extracellular enzyme activities exhibited higher values under high aw, while phenol oxidase activity and prokaryote biomass increased at lower aw. This shift occurred at both depths but was more pronounced at the surface, possibly due to the more extreme conditions (up to 0.7 aw). The increased levels of extracellular polymeric substances and carotenoids developed at low aw may help protect microorganisms in high salinity and drought environments. However, these harsh conditions may interfere with the activity of hydrolytic enzymes and their producers, while promoting the growth of resistant prokaryotes and their capacity to obtain C and N sources from recalcitrant compounds. The resilience of biofilms in hypersaline lakes under extreme conditions is given by their resistant biochemichal structure and the adaptability of their microbial functioning.

Impact of microorganisms on Blasius–Rayleigh–Stokes flow and heat transfer of nanofluid: A numerical study

AbstractIn this article, we present a numerical study of unsteady flow and heat transfer in a viscous‐based nanofluid, examining the impact of microorganisms on a moving surface emerging from a moving slot. This gives rise to a new type of boundary layer flow, which can resemble that over a stretching or shrinking surface depending on the motion of the slot. To solve the partial differential equations governing the bio‐convectional flow, we employ the Blasius–Rayleigh–Stokes variable and transform the equations into a corrected similar form. Our numerical solutions reveal the presence of dual solutions within a specific range of the moving slot parameter. Our findings have important implications for understanding the behavior of nanofluids and microorganisms in dynamic flow environments.

Defluorination of various perfluoro alkyl acids and selected PFOA and PFOS monomers by Acidimicrobium sp. Strain A6 enrichment cultures

Per- and polyfluoroalkyl substances (PFAS) have emerged as a diverse class of environmental pollutants, garnering increasing attention due to their various structural types and potential ecological impacts. The impact of select PFAS on environmental microorganisms and the potential for microbial degradation of certain PFAS are timely research topics. In this study, we conducted a series of batch incubation to investigate the effects of C4-C10 perfluoroalkyl carboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs), as well as linear and branched perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) monomers, on the Feammox reaction and Acidimicrobium sp. A6 (A6), a microbe known to degrade PFOA and PFOS. We explored the defluorination ability of A6 cultures with these PFAS, evaluating their response to varying chemical structures. While A6 cultures demonstrated the ability to degrade a wide range of PFAAs (11.5–56.9 % reduction over 120 days), challenges were noted with specific compounds like PFPeA and double-branched PFCAs and PFSAs, which also showed reduced ammonium removal. Additionally, exposure to the selected PFAS resulted in notable shifts in the microbial community within the A6 enrichment cultures, indicating a selective pressure that benefits certain strains (e.g., increased percentages of Acidimicrobium, Paraburkholderia, and Desulfosporosinus in several PFCA, PFSA and PFOA/PFOS monomers enriched cultures). These insights contribute to our understanding of microbial-PFAS interactions and are instrumental in developing bioremediation strategies for PFAS-impacted environments.

Cystic fibrosis sputum media induces an overall loss of antibiotic susceptibility in Mycobacterium abscessus

AbstractMycobacterium abscessus complex (MABSC) comprises a group of environmental microorganisms, which are a concerning cause of opportunistic respiratory infections in patients with cystic fibrosis or bronchiectasis. Only 45.6% of MABSC treatments are successful, and therefore this is a need to discover new antimicrobials that can treat these pathogens. However, the transferability of outcomes to the clinic is flawed by an inability to accurately represent the lung environment within the laboratory. Herein, we apply two preestablished formulations of sputum media (ACFS and SCFM1) to MABSC antibiotic susceptibility testing. Using conventional broth microdilution, we have observed strain and antibiotic dependent alterations in antimicrobial sensitivity in each sputum media compared standard laboratory media (7H9), with an overall reduction in susceptibility within the physiologically relevant conditions. We provide a timely contribution to the field of M. abscessus antibiotic discovery by emphasising the need for improved physiological relevance.

Controlled entropy in tetra-hybrid nono-fluid helmholtz electroosmotic with motile germs via complex peristaltic pumping

Motile microorganisms, such as bacteria, can be engineered to transport medications directly to certain organs, such as cancer, tumors, enhancing drug efficacy and minimizing systemic side effects. These microorganisms can also be programmed to target and eliminate harmful bacteria, offering a novel approach to infection control. In parallel, functionalized nanomaterials show significant promise for precise manipulation of biological fluids. This focused approach improves drug efficacy while reducing systemic negative effects. Also, motile bacteria can be engineered to target and remove dangerous bacteria, providing a fresh approach to infection control. Nanomaterials with various functions show prodigious potential for precise operation of biological fluids. Tetra-hybrid nano-particles exhibit special electrical, optical, and thermal properties. They are composed of gold, silver, alumina, and titania. The streaming flow phenomena that result from the interactions of these nanocomposites with non-Newtonian biofluids, such as blood, can be studied using computational modeling. Considerations are made for forces such as non-Newtonian rheology, localized laser irradiation, and magnetohydrodynamics. Complex cellular trapping patterns are captured by predictions for temperature, velocity, and nanoparticle concentration profiles. Biocompatible multimodal nano-assemblies under magnetic actuation and thermos-plasmonic effects are used to exhibit precision biofluid control. To optimize, engineering parameters are visually analyzed. The unique features of tetra-hybrid nanoparticles, paired with motile microorganisms and non-Newtonian biofluid dynamics, allow for more precise therapeutic techniques, such as targeted medication administration and hyperthermia cancer treatment. By visualizing key engineering parameters, these findings highlight the potential for improved therapeutic strategies, such as targeted drug delivery and hyperthermia-based cancer treatments, enabled by the integration of tetra-hybrid nanoparticles and motile microorganisms in complex biofluid environments.

Research progress in isolation strategies and bioactive substances of microorganisms in extreme environments

Microbial resources are diverse and abundant, serving as a crucial source for the discovery of bioactive substances. However, as the research on microbial secondary metabolites deepens, discovering new microorganisms and novel bioactive secondary metabolites from conventional environments is becoming increasingly challenging. The microorganisms inhabiting extreme environments have unique physiological characteristics and can develop distinctive metabolic pathways, holding immense potential for producing chemically diverse and novel bioactive secondary metabolites. This article comprehensively overviews the recent advancements in the isolation strategies of microorganisms from extreme environments and the research progress in their bioactive substances, including antimicrobial, anticancer, and antioxidant compounds. This review aims to serve as a reference for the development and utilization and the related studies of the microbial resources in extreme environments.

Long-Term Autotrophic Growth and Solar-to-Chemical Conversion in Shewanella Oneidensis MR-1 through Light-Driven Electron Transfer.

Members of the genus Shewanella are known for their versatile electron accepting routes, which allow them to couple decomposition of organic matter to reduction of various terminal electron acceptors for heterotrophic growth in diverse environments. Here, we report autotrophic growth of Shewanella oneidensis MR-1 with photoelectrons provided by illuminated biogenic CdS nanoparticles. This hybrid system enables photosynthetic oscillatory acetate production from CO2 for over five months, far exceeding other inorganic-biological hybrid system that can only sustain for hours or days. Biochemical, electrochemical and transcriptomic analyses reveal that the efficient electron uptake of S. oneidensis MR-1 from illuminated CdS nanoparticles supplies sufficient energy to stimulate the previously overlooked reductive glycine pathway for CO2 fixation. The continuous solar-to-chemical conversion is achieved by photon induced electric recycling in sulfur species. Overall, our findings demonstrate that this mineral-assisted photosynthesis, as a widely existing and unique model of light energy conversion, could support the sustained photoautotrophic growth of non-photosynthetic microorganisms in nutrient-lean environments and mediate the reversal of coupled carbon and sulfur cycling, consequently resulting in previously unknown environmental effects. In addition, the hybrid system provides a sustainable and flexible platform to develop a variety of solar products for carbon neutrality.

Distribution of bacterial pathogens and antimicrobial resistance in cows with clinical mastitis in a dairy farm, Türkiye

This study aimed to identify the pathogens causing clinical mastitis (CM) and their resistance levels to six common antimicrobials in a dairy farm in Turkey. A total of 973 CM milk samples were cultured and a Kirby-Bauer disc diffusion method was performed for antimicrobial susceptibility. While 64.0% (623/973) of CM samples were culture-positive, 36.0% (350/973) of CM samples yielded no growth. Escherichia coli was the most frequently isolated pathogen (36.3%), followed by coagulase-negative staphylococci (8.3%), Streptococcus dysgalactiae (7.3%), Staphylococcus aureus (3.1%), Streptococcus uberis (1.5%), Enterococcus spp. (1.4%), Mycoplasma spp. (1.4%), Streptococcus agalactiae (0.7%), and Corynebacterium spp. (0.4%). Antimicrobial resistance was higher (P > 0.01) to amoxicillin/clavulanic acid (AMC, 32.3%) than that to enrofloxacin (ENR, 23.4%), cefoperazone (CFP, 17.9%), cefquinome (CEQ, 17.7%), penicillin G (P, 15.2%), and gentamicin (CN, 3.6%) in culture-positive 642 isolates. For E. coli isolates, percentage of resistance to AMC, ENR, CFP, CEQ, P, and CN was 37.7, 30.6, 24.4, 23.2, 5.9, and 1.1%, respectively. Resistance to AMC (31.2%) and P (46.3%) was higher in CNS than Strep. dysgalactiae isolates (1.5% and 12.7%), respectively. Multidrug resistance was detected in 34 E. coli isolates (9.6%), 7 CNS isolates (8.6%), and 2 Strep. dysgalactiae (2.8%). In conclusion, the higher identification of E. coli demonstrated the higher risk of environmental microorganisms for CM in this study. Higher resistance to commonly used five of six antimicrobials showed the requirement of frequent bacteriological and antimicrobial susceptibility tests for CM. Thus, these implementations could increase treatment efficacy in cows and reduce antimicrobial resistance.

The role of the AHR in host-pathogen interactions.

Host-microorganism encounters take place in many different ways and with different types of outcomes. Three major types of microorganisms need to be distinguished: (1) pathogens that cause harm to the host and must be controlled; (2) environmental microorganisms that can be ignored but must be controlled at higher abundance; and (3) symbiotic microbiota that require support by the host. Recent evidence indicates that the aryl hydrocarbon receptor (AHR) senses and initiates signalling and gene expression in response to a plethora of microorganisms and infectious conditions. It was originally identified as a receptor that binds xenobiotics. However, it was subsequently found to have a critical role in numerous biological processes, including immunity and inflammation and was recently classified as a pattern recognition receptor. Here we review the role of the AHR in host-pathogen interactions, focusing on AHR sensing of different microbial classes, the ligands involved, responses elicited and disease outcomes. Moreover, we explore the therapeutic potential of targeting the AHR in the context of infection.

The Microbiologically Influenced Corrosion and Protection of Pipelines: A Detailed Review

Microbial corrosion is the deterioration of materials associated with microorganisms in environments, especially in oil- and gas-dominated sectors. It has been widely reported to cause great losses to industrial facilities such as drainage systems, sewage structures, food-processing equipment, and oil and gas facilities. Generally, bacteria, viruses, and other microorganisms are the most important microorganisms associated with microbial corrosion. The destructive nature of these microorganisms differs based on the kind of bacteria involved in the corrosion mechanism. Amongst the microorganisms related to microbial corrosion, sulfate-reducing bacteria (SRB) is reported to be the most common harmful bacteria. The detailed mechanistic explanations relating to the corrosion of pipelines by sulfate-reducing bacteria are discussed. The mechanism of microbial corrosion in pipelines showing the formation of pitting corrosion and cathodic depolarization is also reported. The current review provides theoretical information for the control and protection of pipelines caused by microbial corrosion and how new eco-friendly protection methods could be explored.

Microbial Community Structure in the Taklimakan Desert: The Importance of Nutrient Levels in Medium and Culture Methods.

Although the Taklimakan Desert lacks the necessary nutrients and conditions to support an extensive ecosystem, it is a treasure trove of extremophile resources with special structures and functions. We analyzed the bacterial communities using oligotrophic medium and velvet cloth replicate combined with an extended culture duration. We isolated numerous uncultured microorganisms and rare microorganisms belonging to genera not often isolated or recently described, such as Aliihoeflea, Halodurantibacterium, and Indioceanicola. A total of 669 strains were isolated from the soil of the Taklimakan Desert, which were classified into 5 phyla, 7 classes, 25 orders, 42 families, 83 genera, and 379 species. Among them, 148 strains were potential new species. Our data show that even when working with samples from extreme environments, simple approaches are still useful for cultivating stubborn microbes. Through comparing the isolation effects of different nutrient levels on microbial diversity and abundance, the results show that reducing the nutrient level of the medium was more conducive to improving the culturability of microorganisms in low-nutrient environments, while the high-nutrient medium was more suitable for the isolation of dominant fast-growing strains. This study helps to better reflect the diversity of microbial resources and lays a foundation for the further research and utilization of soil microbial resources in the Taklimakan Desert.

Microplastics stress alters microorganism community structure and reduces the production of biogenic dimethylated sulfur compounds

AbstractDimethylsulfoniopropionate (DMSP) is a plentiful organic sulfur metabolite and the primary precursor for dimethyl sulfide (DMS), which plays a crucial role in global sulfur cycling, the formation of clouds, and cooling the warming earth. The origin and fate of DMSP are intricately linked to marine microorganisms, making the variation of the microorganism community crucial for DMSP dynamics. Nonetheless, the impact of pervasive marine microplastics on microorganisms and processes related to DMSP synthesis and degradation remains insufficiently investigated. To bridge this gap, a 14‐d deck‐based microcosm experiment was conducted, revealing that microplastics significantly altered the composition of microorganism communities and dramatically inhibited the release of DMS and DMSP. Furthermore, multivariate analysis demonstrated that the variations both in environmental variables and microorganism communities caused by microplastics were forcing factors in reducing DMS and DMSP release. In addition, the predicted function of the bacterial community showed a significant reduction in the presence of dddP and dmdA genes when exposed to microplastics, which directly disrupted both the demethylation and cleavage pathways of DMSP. These results indicate that the release of DMS and DMSP in marine ecosystems can be significantly affected by microplastics through influencing microorganisms. Thus, it is imperative to conduct research on controlling the synthesis and degradation of DMSP in the ocean, particularly in response to these environmental pollution issues. Such research can help discern new patterns from specific phenomena and identify crucial processes.

Myxococcus xanthus fruiting body morphology is important for spore recovery after exposure to environmental stress.

Environmental microorganisms have evolved a variety of strategies to survive fluctuations in environmental conditions, including the production of biofilms and differentiation into spores. Myxococcus xanthus are ubiquitous soil bacteria that produce starvation-induced multicellular fruiting bodies filled with environmentally resistant spores (a specialized biofilm). Isolated spores have been shown to be more resistant than vegetative cells to heat, ultraviolet radiation, and desiccation. The evolutionary advantage of producing spores inside fruiting bodies is not clear. Here, we examine a hypothesis that the fruiting body provides additional protection from environmental insults. We developed a high-throughput method to compare the recovery (outgrowth) of distinct cell types (vegetative cells, free spores, and spores within intact fruiting bodies) after exposure to ultraviolet radiation or desiccation. Our data indicate that haystack-shaped fruiting bodies protect spores from extended UV radiation but do not provide additional protection from desiccation. Perturbation of fruiting body morphology strongly impedes recovery from both UV exposure and desiccation. These results hint that the distinctive fruiting bodies produced by different myxobacterial species may have evolved to optimize their persistence in distinct ecological niches.IMPORTANCEEnvironmental microorganisms play an important role in the production of greenhouse gases that contribute to changing climate conditions. It is imperative to understand how changing climate conditions feedback to influence environmental microbial communities. The myxobacteria are environmentally ubiquitous social bacteria that influence the local microbial community composition. Defining how these bacteria are affected by environmental insults is a necessary component of predicting climatic feedback effects. When starved, myxobacteria produce multicellular fruiting bodies filled with spores. As spores are resistant to a variety of environmental insults, the evolutionary advantage of building a fruiting body is not clear. Using the model myxobacterium, Myxococcus xanthus, we demonstrate that the tall, haystack-shaped fruiting body morphology enables significantly more resistance to UV exposure than the free spores. In contrast, fruiting bodies are slightly detrimental to recovery from extended desiccation, an effect that is strongly exaggerated if fruiting body morphology is perturbed. These results suggest that the variety of fruiting body morphologies observed in the myxobacteria may dictate their relative resistance to changing climate conditions.

Response of earthworm enzyme activity and gut microbial functional diversity to carbendazim in the manured soil.

The effect of pesticide pollution on environmental microorganisms in soil has become the focus of widespread concern in society today. The response of earthworm gut and surrounding soil microbial functional diversity and enzyme activity to carbendazim (CBD) was studied in a soil-earthworm ecosystem amended with manure. In the experiment, CBD was added to the manured soil (MS). Meanwhile, the pesticide treatment without manure and the control treatment without pesticides were also set up. The activities of catalase (CAT) and acetylcholinesterase (AChE) were measured to evaluate the toxicity of CBD. The Biolog method was used to assess the functional diversity of the microbial community. In the 2 mg/kg CBD treatment, earthworm AChE activity decreased significantly in the MS after 14 d, which occurred earlier than in the un-manured soil (NS). The changes of earthworm CAT activity in the pesticide treatments showed a trend of initially increasing and then maintaining at a high activity level. However, the CAT activities at 28 d in the manured soils were clearly lower than that at 7 d for both the CBD treatments, while they remained stable in the control treatments. The carbon source utilization, Simpson index, Shannon index, and McIntosh index of soil microorganisms in the MS treatments were significantly higher than those in the NS treatments. The overall activity of earthworm gut microorganisms in the MS treated with 2 mg/kg CBD was higher than that in the control. Also, CBD treatment (2 mg/kg) increased significantly the Simpson index and McIntosh index of earthworm gut microorganisms. The results indicated that the enzyme activities in the manured soils increased before 7 d for the pesticide treatments. Furthermore, exposure to CBD at a high concentration in the MS not only led to the earlier inhibition of earthworm enzyme activity but also significantly improved the overall activity of earthworm gut microorganisms and microbial functional diversity. This study revealed the ecotoxicological effects of earthworms in response to pesticide stress following the use of organic fertilizers under facility environmental conditions, which can provide a theoretical basis for the remediation of pesticide pollution in soil in the future.

Photoelectron-promoted metabolism of sulphate-reducing microorganisms in substrate-depleted environments.

Sulphate-reducing microorganisms, or SRMs, are crucial to organic decomposition, the sulphur cycle, and the formation of pyrite. Despite their low energy-yielding metabolism and intense competition with other microorganisms, their ability to thrive in natural habitats often lacking sufficient substrates remains an enigma. This study delves into how Desulfovibrio desulfuricans G20, a representative SRM, utilizes photoelectrons from extracellular sphalerite (ZnS), a semiconducting mineral that often coexists with SRMs, for its metabolism and energy production. Batch experiments with sphalerite reveal that the initial rate and extent of sulphate reduction by G20 increased by 3.6 and 3.2 times respectively under light conditions compared to darkness, when lactate was not added. Analyses of microbial photoelectrochemical, transcriptomic, and metabolomic data suggest that in the absence of lactate, G20 extracts photoelectrons from extracellular sphalerite through cytochromes, nanowires, and electron shuttles. Genes encoding movement and biofilm formation are upregulated, suggesting that G20 might sense redox potential gradients and migrate towards sphalerite to acquire photoelectrons. This process enhances the intracellular electron transfer activity, sulphur metabolism, and ATP production of G20, which becomes dominant under conditions of carbon starvation and extends cell viability in such environments. This mechanism could be a vital strategy for SRMs to survive in energy-limited environments and contribute to sulphur cycling.

Prevalence of antibiotic resistance genes in different drinking water treatment processes in a northwest Chinese city.

Antibiotic resistance genes (ARGs) are an emerging issue which are receiving increasing concerns in drinking water safety. However, the factors (e.g. treatment processes and water quality) affecting the removal efficiency of ARGs in the drinking water treatment plants (DWTPs) is still unclear. This work investigated the ARG profiles in each treatment process of two DWTPs located in a northwest Chinese city. The results showed that tetracycline and sulfonamide resistance genes were predominant among the 14 targeted ARGs. After the treatment, the Z water treatment plant which demonstrated a higher removal rate of ARGs (ranging from 50 to 80%), compared to the S plant (50-75%). And the average removal rate of tetracycline resistance genes (tetA, tetG, tetQ, tetX) was about 49.18% (S plant) and 67.50% (Z plant), as well as the removal rate of 64.2% and 72.9% for sulfonamide resistance (sul1 and sul2) at S and Z water plants, respectively. It was found that the relative abundance of main microbial communities (such as Bacteroidota, Actinobacteria, Verrucomicrobiota, Roseomonas), α-diversity index, as well as the abundance of pathogenic bacteria were all significantly reduced after different treatment processes. Network co-occurrence analysis revealed that Methylocystis possibly was the potential host for most ARGs, and sul1 was found across a broad spectrum of microorganisms in the drinking water environment. Adonis analysis showed that heavy metals and microbial communities explain solely 44.1% and 35.7% of variances of ARGs within DWTPs. This study provides insights into the contamination status and removal efficiencies of ARGs in DWTPs, offering valuable references for future studies on ARG removal, propagation, and diffusion patterns in drinking water treatment.

Experimental and numerical study on upper-room Far-UVC system under different ventilation schemes to disinfect airborne microorganisms in indoor environments

Many deadly infectious diseases are transmitted through airborne routes in indoor environments. Far UV upper-room system combined with proper ventilation is regarded as an effective approach to disinfect airborne microorganisms. Despite the current advances in the far UV upper-room system, various types of data are still lacking to guide the efficient design and the safe operation. This study combines field air sampling, laboratory experiments and computational fluid dynamics simulations to advance the knowledge on the potential of far UV radiation for disinfection and its safety design. Our findings reveal that seven out of the eight measured room spaces are categorised as slightly polluted (1201–2000 CFU m−3) or polluted (>2000 CFU m−3). Proteobacteria and Firmicutes constitute 65.2 ± 10.6 % and 21.2 ± 5.68 % of the bacterial composition in congregate settings, respectively. Ultraviolet radiation proves effective in deactivating pathogenic microorganisms, characterized by a decay rate constant ranging from 0.0446 m2 J−1 to 0.464 m2 J−1, depending on the wavelength and the type of pathogenic microorganisms. The time response of Ultraviolet radiation is up to 12 min to achieve 92.1 % sterilisation. Despite the reduction in the sterilisation ratio of Ultraviolet radiation, maintaining a high ventilation rate is highly recommended to eliminate genetic material from pathogenic microorganisms. When the excimer lamp is installed higher than 1.9 m above the floor level, the radiation intensities at both standing and sitting height become lower than the safety threshold value of 0.166 W m−2. A combination of UV radiation at 222 nm and ventilation is effective for neutralising both gram-positive and -negative bacteria and can contribute to stop the spread of infectious diseases in congregate settings.

Exploring the microbiome: New horizons for emerging therapeutics

The document discusses the topic of microbiomes, specifically focusing on the human microbiome and its various aspects. It starts by explaining the concept of human microbiota, which refers to the collection of microorganisms that live in and interact with the human body. The document highlights the importance of these microbial ecosystems in maintaining overall health and wellbeing. The composition and function of the gut microbiome undergo significant changes during the first year of life, especially with the introduction of solid foods. The document discusses the different bacterial phyla that dominate the gut microbiome in neonatal infants and adults. It also mentions the role of the human gut microbiome in various health conditions such as liver diseases, diabetes, inflammatory bowel disease, autoimmune diseases, colon cancer, and central nervous system disorders. The document highlights the different sequencing techniques used in microbiome research, such as ITS sequencing, PCR amplicon-based sequencing, and shotgun metagenomic sequencing. It also discusses the concept of the halobiont and holo genome in relation to the microbiome. The document emphasizes the importance of studying the microbiome in the context of ecosystem health and discusses the impact of human populations on environmental microorganisms. Furthermore, the document covers the microbial barrier in the human gut, the role of the gut microbiota in various metabolic processes, and the application of gut microbiomes in bioengineering, both in humans and other organisms. Lastly, it discusses the importance of dietary interventions, prebiotics, and the role of various diets in influencing the composition of the gut microbiome and treating gastrointestinal disorders. Overall, the document provides a comprehensive overview of the human microbiome and its significance in health and disease, as well as its potential applications in bioengineering and dietary interventions.

From Mechanism-Based Retaining Glycosidase Inhibitors to Activity-Based Glycosidase Profiling.

Activity-based protein profiling (ABPP) is an effective technology for the identification and functional annotation of enzymes in complex biological samples. ABP designs are normally directed to an enzyme active site nucleophile, and within the field of Carbohydrate-Active Enzymes (CAZymes), ABPP has been most successful for those enzymes that feature such a residue: retaining glycosidases (GHs). Several mechanism-based covalent and irreversible retaining GH inhibitors have emerged over the past sixty years. ABP designs based on these inhibitor chemistries appeared since the turn of the millennium, and we contributed to the field by designing a suite of retaining GH ABPs modeled on the structure and mode of action of the natural product, cyclophellitol. These ABPs enable the study of both exo- and endo-acting retaining GHs in human health and disease, for instance in genetic metabolic disorders in which retaining GHs are deficient. They are also finding increasing use in the study of GHs in gut microbiota and environmental microorganisms, both in the context of drug (de)toxification in the gut and that of biomass polysaccharide processing for future sustainable energy and chemistries. This account comprises the authors' view on the history of mechanism-based retaining GH inhibitor design and discovery, on how these inhibitors served as blueprints for retaining GH ABP design, and on some current and future developments on how cyclophellitol-based ABPs may drive the discovery of retaining GHs and their inhibitors.