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Bioresource Technology Jun 2024Aromatic amino acids (AAA) and derived compounds have enormous commercial value with extensive applications in the food, chemical and pharmaceutical fields. Microbial... (Review)
Review
Aromatic amino acids (AAA) and derived compounds have enormous commercial value with extensive applications in the food, chemical and pharmaceutical fields. Microbial production of AAA and derived compounds is a promising prospect for its environmental friendliness and sustainability. However, low yield and production efficiency remain major challenges for realizing industrial production. With the advancement of synthetic biology, microbial production of AAA and derived compounds has been significantly facilitated. In this review, a comprehensive overview on the current progresses, challenges and corresponding solutions for AAA and derived compounds biosynthesis is provided. The most cutting-edge developments of synthetic biology technology in AAA and derived compounds biosynthesis, including CRISPR-based system, genetically encoded biosensors and synthetic genetic circuits, were highlighted. Finally, future prospects of modern strategies conducive to the biosynthesis of AAA and derived compounds are discussed. This review offers guidance on constructing microbial cell factory for aromatic compound using synthetic biology technology.
PubMed: 38942210
DOI: 10.1016/j.biortech.2024.131050 -
Acta Biomaterialia Jun 2024A wide variety of microorganisms have been closely linked to metal corrosion in the form of adherent surface biofilms. Biofilms allow the development and maintenance of... (Review)
Review
A wide variety of microorganisms have been closely linked to metal corrosion in the form of adherent surface biofilms. Biofilms allow the development and maintenance of locally corrosive environments and/or permit direct corrosion including pitting corrosion. The presence of numerous genetically distinct microorganisms in the oral environment poses a threat to the integrity and durability of the surface of metallic prostheses and implants used in routine dentistry. However, the association between oral microorganisms and specific corrosion mechanisms is not clear. It is of practical importance to understand how microbial corrosion occurs and the associated risks to metallic materials in the oral environment. This knowledge is also important for researchers and clinicians who are increasingly concerned about the biological activity of the released corrosion products. Accordingly, the main goal was to comprehensively review the current literature regarding oral microbiologically influenced corrosion (MIC) including characteristics of biofilms and of the oral environment, MIC mechanisms, corrosion behavior in the presence of oral microorganisms and potentially mitigating technologies. Findings included that oral MIC has been ascribed mostly to aggressive metabolites secreted during microbial metabolism (metabolite-mediated MIC). However, from a thermodynamic point of view, extracellular electron transfer mechanisms (EET-MIC) through pili or electron transfer compounds cannot be ruled out. Various MIC mitigating methods have been demonstrated to be effective in short term, but long term evaluations are necessary before clinical applications can be considered. Currently most in-vitro studies fail to simulate the complexity of intraoral physiological conditions which may either reduce or exacerbate corrosion risk, which must be addressed in future studies. STATEMENT OF SIGNIFICANCE: A thorough analysis on literature regarding oral MIC (microbiologically influenced corrosion) of biomedical metallic materials has been carried out, including characteristics of oral environment, MIC mechanisms, corrosion behaviors in the presence of typical oral microorganisms and potential mitigating methods (materials design and surface design). There is currently a lack of mechanistic understanding of oral MIC which is very important not only to corrosion researchers but also to dentists and clinicians. This paper discusses the significance of biofilms from a biocorrosion perspective and summarizes several aspects of MIC mechanisms which could be caused by oral microorganisms. Oral MIC has been closely associated with not only the materials research but also the dental/clinical research fields in this work.
PubMed: 38942189
DOI: 10.1016/j.actbio.2024.06.032 -
Current Biology : CB Jun 2024A dynamic mucous layer containing numerous micro-organisms covers the surface of corals and has multiple functions including both removal of sediment and "food...
A dynamic mucous layer containing numerous micro-organisms covers the surface of corals and has multiple functions including both removal of sediment and "food gathering." It is likely to also act as the primary barrier to infection; various proteins and compounds with antimicrobial activity have been identified in coral mucus, though these are thought to be largely or exclusively of microbial origin. As in Hydra, anti-microbial peptides (AMPs) are likely to play major roles in regulating the microbiomes of corals. Some eukaryotes employ a complementary but less obvious approach to manipulate their associated microbiome by interfering with quorum signaling, effectively preventing bacteria from coordinating gene expression across a population. Our investigation of immunity in the reef-building coral Acropora millepora, however, led to the discovery of a coral gene referred to here as AmNtNH1 that can inactivate a range of acyl homoserine lactones (AHLs), common bacterial quorum signaling molecules, and is induced on immune challenge of adult corals and expressed during the larval settlement process. Closely related proteins are widely distributed within the Scleractinia (hard corals) and some other cnidarians, with multiple paralogs in Acropora, but their closest relatives are bacterial, implying that these are products of one or more lateral gene transfer events post-dating the cnidarian-bilaterian divergence. The deployment by corals of genes used by bacteria to compete with other bacteria reflects a mechanism of microbiome manipulation previously unknown in Metazoa but that may apply more generally.
PubMed: 38942019
DOI: 10.1016/j.cub.2024.05.073 -
Journal of Hazardous Materials Jun 2024Fluoroquinolone antibiotics (FQs) have been used worldwide due to their extended antimicrobial spectrum. However, the overuse of FQs leads to frequent detection in the...
Fluoroquinolone antibiotics (FQs) have been used worldwide due to their extended antimicrobial spectrum. However, the overuse of FQs leads to frequent detection in the environment and cannot be efficiently removed. Microalgae-based constructed wetland systems have been proven to be a relatively proper method to treat FQs, mainly by microalgae, plants, microorganisms, and sediments. To improve the removal efficiency of microalgae-constructed wetland, a systematic molecular design, screening, functional, and risk evaluation method was developed using three-dimensional quantitative structure-activity relationship models, molecular dynamics simulation, molecular docking, and TOPKAT approaches. Five designed ciprofloxacin alternatives with improved bactericidal effects and lower human health risks were found to be more easily degraded by microalgae (16.11-167.88 %), plants (6.72-58.86 %), microorganisms (9.10-15.02 %), and sediments (435.83 %-1763.51 %) compared with ciprofloxacin. According to the mechanism analysis, the removal effect of the FQs can be affected via changes in the number, bond energy, and molecular descriptors of favorable and unfavorable amino acids. To the best of our knowledge, this is the first comprehensive study of improving the microalgae, plants, microorganisms, and sediment removal efficiency of FQs in constructed wetlands, which provides theoretical support for the treatment of FQ pollution.
PubMed: 38941832
DOI: 10.1016/j.jhazmat.2024.134946 -
Water Research Jun 2024The biological carbon pump in karst areas is of great significance for maintaining the effectiveness of karst carbon sinks. However, the spatial distribution and...
The biological carbon pump in karst areas is of great significance for maintaining the effectiveness of karst carbon sinks. However, the spatial distribution and carbon-fixing potential of microorganisms in different aquifers within karst areas remain poorly understood. In this study, the distribution patterns, ecological roles, and environmental drivers of microbiota associated with CO fixation were investigated in karst groundwater (KW), porous groundwater (PW), fractured groundwater (FW), and surface water (SW) within a typical karst watershed, located in Guilin, southwest China. KW, PW, and FW displayed the similar community structure and indicative carbon-fixing bacteria composition, which were dominated by chemoautotrophic bacteria compared to SW. Higher abundances of indicative carbon-fixing bacteria and carbon-fixing genes, as well as richer proportions of microbial-derived DOC, indicated the more significant microbial carbon-fixing potential in KW and PW. At the profile of KW, a carbon-fixing hotspot was discovered at the depths of 0-50 m. Correlation analysis between carbon-fixing bacteria and DOC revealed that the chemoautotrophic process driven by nitrogen and sulfur oxidation predominated the microbial carbon fixation in groundwater. Co-occurrence network analysis demonstrated that carbon-fixing bacteria exhibited cooperation with other bacterial taxa in KW, while competition was the dominant interaction in PW. Moreover, carbon-fixing bacteria was found to lead bacterial assembly more deterministic in KW. The analysis of environmental factors and microbial diversity illustrated that inorganic carbon and redox state drove community variations across groundwaters. Structural equation model (SEM) further confirmed that ORP was the primary factor influencing the carbon fixation potential. This study provides a new insight into biological carbon fixation in karst aquatic systems, which holds significance in the accurate assessment of karst carbon sinks.
PubMed: 38941678
DOI: 10.1016/j.watres.2024.121979 -
Annual Review of Immunology Jun 2024The intestine is the largest peripheral lymphoid organ in animals, including humans, and interacts with a vast array of microorganisms called the gut microbiota.... (Review)
Review
The intestine is the largest peripheral lymphoid organ in animals, including humans, and interacts with a vast array of microorganisms called the gut microbiota. Comprehending the symbiotic relationship between the gut microbiota and our immune system is essential not only for the field of immunology but also for understanding the pathogenesis of various systemic diseases, including cancer, cardiometabolic disorders, and extraintestinal autoimmune conditions. Whereas microbe-derived antigens are crucial for activating the intestinal immune system, particularly T and B cells, as environmental cues, microbes and their metabolites play a critical role in directing the differentiation of these immune cells. Microbial metabolites are regarded as messengers from the gut microbiota, since bacteria have the ability to produce unique molecules that humans cannot, and many immune cells in the intestine express receptors for these molecules. This review highlights the distinct relationships between microbial metabolites and the differentiation and function of the immune system.
Topics: Humans; Animals; Gastrointestinal Microbiome; Cell Differentiation; B-Lymphocytes; T-Lymphocytes; Bacteria
PubMed: 38941602
DOI: 10.1146/annurev-immunol-090222-102035 -
Analytical Chemistry Jun 2024Evaluating the dynamic interaction of microorganisms and mammalian cells is challenging due to the lack of suitable platforms for examining interspecies interactions in...
Evaluating the dynamic interaction of microorganisms and mammalian cells is challenging due to the lack of suitable platforms for examining interspecies interactions in biologically relevant coculture conditions. In this work, we demonstrate the interaction between probiotic bacteria ( and ) and A498 human cancer cells , utilizing a hydrogel-based platform in a label-free manner by infrared spectroscopy. The strain recapitulated in the compartment system secretes polypeptide molecules such as nisin, which has been reported to trigger cell apoptosis. We propose a mid-infrared (IR) spectroscopic imaging approach to monitor the variation of biological components utilizing kidney cells (A498) as a model system cocultured with bacteria. We characterized the biochemical composition (i.e., nucleic acids, protein secondary structures, and lipid conformations) label-free using an unbiased measurement. Several IR spectral features, including unsaturated fatty acids, β-turns in protein, and nucleic acids, were utilized to predict cellular response. These features were then applied to establish a quantitative relationship through a multivariate regression model to predict cellular dynamics in the coculture system to assess the effect of nisin on A498 kidney cancer cells cocultured with bacteria. Overall, our study sheds light on the potential of using IR spectroscopic imaging as a label-free tool to monitor complex microbe-host cell interactions in biological systems. This integration will enable mechanistic studies of interspecies interactions with insights into their underlying physiological processes.
PubMed: 38941069
DOI: 10.1021/acs.analchem.4c00894 -
Methods in Molecular Biology (Clifton,... 2024The oral cavity is a habitat for different microorganisms, of which bacteria are best described. Studying different bacterial taxa and their proteins is crucial to...
The oral cavity is a habitat for different microorganisms, of which bacteria are best described. Studying different bacterial taxa and their proteins is crucial to understanding their interactions with the host and other microbes. Also, for bacteria with virulence potential, identifying novel antigenic proteins is essential to finding candidates for the development of vaccines.Here, a workflow for gel-free and label-free protein analysis of oral bacterial species grown in vitro as a biofilm and a planktonic culture is described. Details on cultivation, protein extraction and digestion, peptide cleanup, LC-MS/MS run parameters, and subsequent bioinformatics analysis are included. Challenging steps in the workflow, such as growing different types of bacteria and selecting a suitable protein database, are also discussed. This protocol provides a valuable guide for metaproteomic experiments using multi-species models of oral bacteria.
Topics: Proteomics; Mouth; Tandem Mass Spectrometry; Chromatography, Liquid; Bacterial Proteins; Humans; Bacteria; Microbiota; Biofilms; Computational Biology; Proteome; Workflow
PubMed: 38941022
DOI: 10.1007/978-1-0716-3910-8_14 -
Methods in Molecular Biology (Clifton,... 2024Fishery products are one of the main human nutritional sources, and due to the consumption increase, the quality of the derived products may be modified, during...
Fishery products are one of the main human nutritional sources, and due to the consumption increase, the quality of the derived products may be modified, during catching, technological processing, and storage. Detection and identification of pathogenic and spoilage microorganisms in fishery products is needed because the first may be involved in human diseases, while the second is responsible of significant economic losses. In this sense, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method and computational analysis of MS data are useful tools for characterizing and identifying different microorganisms and to develop promising strategies for food science investigations. Moreover, in the past decade, metaproteomic methodologies have progressed for the study of microorganisms isolated from their natural samples and independently of the culture restrictions. Metaproteomics enables assessment of proteins and pathways from individual members of the consortium. Metaproteomics can provide a detailed understanding of which organisms occupy specific metabolic niches, how they interact, and how they utilize nutrients, and these insights can be obtained directly from environmental samples.According to that, the sample preparation of the fishery product, the LC-ESI-MS/MS dedicated method, and the MS data analysis were described in the present chapter to obtain the metaproteomic analysis of the respective microbiomes or microbial communities.
Topics: Proteomics; Tandem Mass Spectrometry; Chromatography, Liquid; Microbiota; Spectrometry, Mass, Electrospray Ionization; Fisheries; Humans; Fish Products; Animals; Food Microbiology
PubMed: 38941017
DOI: 10.1007/978-1-0716-3910-8_9 -
Methods in Molecular Biology (Clifton,... 2024The proteomic approach plays a key role to characterize a biological system at any given time. In recent years, advances in proteomics have led to an increasing...
The proteomic approach plays a key role to characterize a biological system at any given time. In recent years, advances in proteomics have led to an increasing application in all biological fields, including plant matrices and associated microbiome studies. However, extracting adequate protein samples remains the most critical step for any plant proteomics study. The protein extraction protocols proposed for the phyllosphere involve an initial leaf washing step; however, this is an approach only applicable if interest is restricted to epiphytes. A metaproteomic approach is required to obtain an overall picture and consequently an extraction that considers proteins derived from the plant, epiphytic and endophytic microorganisms. The most commonly used extractions for plant tissue involve the use of phenol or TCA-acetone. However, for efficient protein recovery is essential to remove interfering components abundant in plant tissues, such as polysaccharides, lipids, and phenolic compounds. A well-proven protocol on the basis of a combination of TCA-acetone and phenol extraction is presented here, obtaining some cleaned protein pellets, suitable for electrophoresis and subsequent proteomics studies. Important points for the success of this protocol are (i) a proper sampling and sample preparation, (ii) maintaining samples at a low temperature during extraction and using protease inhibitors, (iii) an initial step in TCA-acetone to remove part of the interfering substances, and (iv) careful recovery of the phenolic phase. Furthermore, the protocol is timesaving and can be completed in one working day.
Topics: Plant Proteins; Proteomics; Plant Leaves; Acetone; Phenol; Plants; Trichloroacetic Acid
PubMed: 38941013
DOI: 10.1007/978-1-0716-3910-8_5