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The ISME Journal Jun 2024Nitrous oxide (N2O) is a potent greenhouse gas of primarily microbial origin. Oxic and anoxic emissions are commonly ascribed to autotrophic nitrification and...
Nitrous oxide (N2O) is a potent greenhouse gas of primarily microbial origin. Oxic and anoxic emissions are commonly ascribed to autotrophic nitrification and heterotrophic denitrification, respectively. Beyond this established dichotomy, we quantitatively show that heterotrophic denitrification can significantly contribute to aerobic nitrogen turnover and N2O emissions in complex microbiomes exposed to frequent oxic/anoxic transitions. Two planktonic, nitrification-inhibited enrichment cultures were established under continuous organic carbon and nitrate feeding, and cyclic oxygen availability. Over a third of the influent organic substrate was respired with nitrate as electron acceptor at high oxygen concentrations (> 6.5 mg/L). N2O accounted for up to one quarter of the nitrate reduced under oxic conditions. The enriched microorganisms maintained a constitutive abundance of denitrifying enzymes due to the oxic/anoxic frequencies exceeding their protein turnover - a common scenario in natural and engineered ecosystems. The aerobic denitrification rates are ascribed primarily to the residual activity of anaerobically synthesized enzymes. From an ecological perspective, the selection of organisms capable of sustaining significant denitrifying activity during aeration shows their competitive advantage over other heterotrophs under varying oxygen availabilities. Ultimately, we propose that the contribution of heterotrophic denitrification to aerobic nitrogen turnover and N2O emissions is currently underestimated in dynamic environments.
PubMed: 38913498
DOI: 10.1093/ismejo/wrae116 -
Microbiology Spectrum Jun 2024Soil salinization usually occurs in arid and semi-arid climate areas from 37 to 50 degrees north latitude and 73 to 123 degrees east longitude. These regions are...
UNLABELLED
Soil salinization usually occurs in arid and semi-arid climate areas from 37 to 50 degrees north latitude and 73 to 123 degrees east longitude. These regions are inhabited by a large number of Coleopteran insects, which play an important role in the ecological cycle. However, little is known about the endosymbiotic microbial taxa and their biological characteristics in these insects. A study of endosymbiotic microorganisms of Coleoptera from Xinjiang, a typical arid and inland saline area, revealed that endosymbiont bacteria with salinity tolerance are common among the endosymbionts of Coleoptera. Functional prediction of the microbiota analysis indicated a higher abundance of inorganic ion transporters and metabolism in these endosymbiont strains. Screening was conducted on the tolerable 11% NaCl levels of G20 (PRJNA754761), and differential metabolite and proteins were performed. The differential metabolites of the strain during the exponential and plateau phases were found to include benzene compounds, organic acids, and their derivatives. These results suggest that the endosymbiotic microorganisms of Coleoptera in this environment have adaptive evolution to extreme environments, and this group of microorganisms is also one of the important resources for mining saline and alkaline-tolerant chassis microorganisms and high-robustness enzymes.
IMPORTANCE
Coleoptera insects, as the first largest order of insect class, have the characteristics of a wide variety and wide distribution. The arid and semi-arid climate makes it more adaptable. By studying the endosymbiont bacteria of Coleoptera insects, we can systematically understand the adaptability of endosymbiont bacteria to host and special environment. Through the analysis of endosymbiont bacteria of Coleoptera insects in different saline-alkali areas in arid and semi-arid regions of Xinjiang, it was found that bacteria in different host samples were resistant to saline-alkali stress. These results suggest that bacteria and their hosts co-evolved in response to this climate. Therefore, this study is of great significance for understanding the endosymbiont bacteria of Coleoptera insects and obtaining extremophile resources (Saline-alkali-resistant chassis strains with modification potential for the production of bulk chemicals and highly robust industrial enzymes).
PubMed: 38912811
DOI: 10.1128/spectrum.00232-24 -
MSphere Jun 2024The microbiome plays vital roles in the life history of mosquitoes, including their development, immunity, longevity, and vector competence. Recent advances in...
UNLABELLED
The microbiome plays vital roles in the life history of mosquitoes, including their development, immunity, longevity, and vector competence. Recent advances in sequencing technologies have allowed for detailed exploration into the diverse microorganisms harbored by these medically important insects. Although these meta-studies have cataloged the microbiomes of mosquitoes in several continents, much of the information currently available for North America is limited to the state of California. In this study, we collected >35,000 mosquitoes throughout Manitoba, Canada, over a 3-year period and then harnessed RNA sequencing and targeted reverse transcriptase-PCR to characterize the microbiomes of the eight most pervasive and important vector and pest species. The consensus microbiome of each species was overwhelmingly composed of viruses but also included fungi, bacteria, protozoa, and parasitic invertebrates. The microbial assemblages were heterogeneous between species, even within the same genus. We detected notable pathogens, including the causal agents of Cache Valley Fever, avian malaria, and canine heartworm. The remaining microbiome consisted largely of putatively insect-specific viruses that are not well characterized, including 17 newly discovered viruses from 10 different families. Future research should focus on evaluating the potential application of these viruses in biocontrol, as biomarkers, and/or in disrupting mosquito vectorial capacity. Interestingly, we also detected viruses that naturally infect honeybees and thrips, which were presumably acquired indirectly through nectar foraging behaviors. Overall, we provide the first comprehensive catalog of the microorganisms harbored by the most common and important mosquito vectors and pests in the Canadian Prairies.
IMPORTANCE
Mosquitoes are the most dangerous animals on the planet, responsible for over 800,000 deaths per year globally. This is because they carry and transmit a plethora of human disease-causing microorganisms, such as West Nile virus and the malaria parasite. Recent innovations in nucleic acid sequencing technologies have enabled researchers unparalleled opportunities to characterize the suite of microorganisms harbored by different mosquito species, including the causal agents of disease. In our study, we carried out 3 years of intensive mosquito surveillance in Canada. We collected and characterized the microorganisms harbored by >35,000 mosquitoes, including the identification of the agents of Cache Valley fever, avian malaria, and canine heartworm. We also detected insect-specific viruses and discovered 17 new viruses that have never been reported. This study, which is the first of its kind in Canada and one of only a handful globally, will greatly aid in future infectious disease research.
PubMed: 38912793
DOI: 10.1128/msphere.00203-24 -
Biology Open Jun 2024Myxomycetes are multinucleate unicellular organisms. They form a plasmodium that moves by protoplasmic flow and prey on microorganisms. When encountering intraspecifics,...
Myxomycetes are multinucleate unicellular organisms. They form a plasmodium that moves by protoplasmic flow and prey on microorganisms. When encountering intraspecifics, the plasmodium has the capacity for 'fusion,' actively approaching and fusing its cells, or 'avoidance,' altering its direction to avoid the other individual. This is an allorecognition ability. However, it remains unclear whether the range of allorecognition extends to other species, and its ecological significance is also obscure. Here, we conducted a quantitative evaluation of contact responses from closely related species of plasmodium to clarify the range of allorecognition behaviors in Myxomycetes. Behavioral assays demonstrated that allorecognition behaviors are specifically observed within individuals of the same species, indicating that these behaviors are a phenomenon unique to intraspecies interactions. Myxomycetes allorecognition is an extremely narrow and inward-focused behavior, suggesting for a highly specialized mechanism.
PubMed: 38912557
DOI: 10.1242/bio.060358 -
Frontiers in Microbiology 2024The world's oceans are challenged by climate change linked warming with typically highly populated coastal areas being particularly susceptible to these effects. Many...
The world's oceans are challenged by climate change linked warming with typically highly populated coastal areas being particularly susceptible to these effects. Many studies of climate change on the marine environment use large, short-term temperature manipulations that neglect factors such as long-term adaptation and seasonal cycles. In this study, a Baltic Sea 'heated' bay influenced by thermal discharge since the 1970s from a nuclear reactor (in relation to an unaffected nearby 'control' bay) was used to investigate how elevated temperature impacts surface water microbial communities and activities. 16S rRNA gene amplicon based microbial diversity and population structure showed no difference in alpha diversity in surface water microbial communities, while the beta diversity showed a dissimilarity between the bays. Amplicon sequencing variant relative abundances between the bays showed statistically higher values for, e.g., Ilumatobacteraceae and Burkholderiaceae in the heated and control bays, respectively. RNA transcript-derived activities followed a similar pattern in alpha and beta diversity with no effect on Shannon's diversity but a significant difference in the beta diversity between the bays. The RNA data further showed more elevated transcript counts assigned to stress related genes in the heated bay that included heat shock protein genes , the co-chaperonin , and the nucleotide exchange factor heat shock protein . The RNA data also showed elevated oxidative phosphorylation transcripts in the heated (e.g., ) compared to control (e.g., ) bay. Furthermore, genes related to photosynthesis had generally higher transcript numbers in the control bay, such as photosystem I () and II genes (). These increased stress gene responses in the heated bay will likely have additional cascading effects on marine carbon cycling and ecosystem services.
PubMed: 38912348
DOI: 10.3389/fmicb.2024.1393538 -
Frontiers in Public Health 2024The human immunodeficiency virus (HIV) remains a critical global health issue, with a pressing need for effective diagnostic and monitoring tools.
BACKGROUND
The human immunodeficiency virus (HIV) remains a critical global health issue, with a pressing need for effective diagnostic and monitoring tools.
METHODOLOGY
This study explored distinctions in salivary metabolome among healthy individuals, individuals with HIV, and those receiving highly active antiretroviral therapy (HAART). Utilizing LC-MS/MS for exhaustive metabolomics profiling, we analyzed 90 oral saliva samples from individuals with HIV, categorized by CD4 count levels in the peripheral blood.
RESULTS
Orthogonal partial least squares-discriminant analysis (OPLS-DA) and other analyses underscored significant metabolic alterations in individuals with HIV, especially in energy metabolism pathways. Notably, post-HAART metabolic profiles indicated a substantial presence of exogenous metabolites and changes in amino acid pathways like arginine, proline, and lysine degradation. Key metabolites such as citric acid, L-glutamic acid, and L-histidine were identified as potential indicators of disease progression or recovery. Differential metabolite selection and functional enrichment analysis, combined with receiver operating characteristic (ROC) and random forest analyses, pinpointed potential biomarkers for different stages of HIV infection. Additionally, our research examined the interplay between oral metabolites and microorganisms such as herpes simplex virus type 1 (HSV1), bacteria, and fungi in individuals with HIV, revealing crucial interactions.
CONCLUSION
This investigation seeks to contribute understanding into the metabolic shifts occurring in HIV infection and following the initiation of HAART, while tentatively proposing novel avenues for diagnostic and treatment monitoring through salivary metabolomics.
Topics: Humans; Saliva; HIV Infections; Biomarkers; Male; Metabolome; Adult; Female; Antiretroviral Therapy, Highly Active; Middle Aged; Chromatography, Liquid; Metabolomics; Tandem Mass Spectrometry; Early Diagnosis; CD4 Lymphocyte Count
PubMed: 38912274
DOI: 10.3389/fpubh.2024.1400332 -
Iranian Journal of Public Health May 2024An important route of microbial transmission is the shared use of these products in beauty salons. We aimed to investigate level of contamination with microorganisms and...
BACKGROUND
An important route of microbial transmission is the shared use of these products in beauty salons. We aimed to investigate level of contamination with microorganisms and their metabolites in shared-use cosmetics in several women's beauty salons.
METHODS
Bacterial and fungal strains from 320 opened/used cosmetic samples were identified according to the Iranian standards for microbial quality of cosmetic products in Golestan Province (North of Iran) during Jul-Sep 2021. In order to assess production of toxins and protease by the predominant bacterial and fungal isolates, multiplex-polymerase chain reaction and the Lowry protein assay were performed, respectively.
RESULTS
Microbial contamination was detected in 180 samples (56.5%), and the highest and lowest rates of microbial contamination were related to skin products (63.88%) and eye beauty products (20%), respectively. The highest level of contamination (> 4,000 colony-forming units/g) was found in toner and face wash samples, and the highest level of contamination was seen in lipstick samples (>20,000 colony-forming units/g). Only one (2%) isolate produced staphylococcal enterotoxin B, while 3 out of 12 (25%) isolates were able to produce protease.
CONCLUSION
The shared-used health and beauty products, face products, in the study area are heavily contaminated. Therefore, it is essential to store used cosmetics in dry and cool places, establish strict inspection regulations for cosmetic products before and after entering the market, and increase awareness of beauty salon workers regarding the appropriate use, sanitary control, and maintenance of health and beauty products.
PubMed: 38912148
DOI: 10.18502/ijph.v53i5.15599 -
Frontiers in Psychiatry 2024The potential role of pathogens, particularly vector-transmitted infectious agents, as a cause of psychosis has not been intensively investigated. We have reported a...
INTRODUCTION
The potential role of pathogens, particularly vector-transmitted infectious agents, as a cause of psychosis has not been intensively investigated. We have reported a potential link between spp. bacteremia and neuropsychiatric symptoms, including pediatric acute onset neuropsychiatric syndrome and schizophrenia. The purpose of this study was to further assess whether spp. exposure or infection are associated with psychosis.
METHODS
In a blinded manner, we assessed the presence of anti- antibodies by indirect immunofluorescence assays (IFA), and infection by amplification of bacterial DNA from blood by quantitative polymerase chain reaction (qPCR), digital PCR (dPCR), and droplet digital PCR (ddPCR) in 116 participants. Participants were categorized into one of five groups: 1) controls unaffected by psychosis ( = 29); 2) prodromal participants ( = 16); 3) children or adolescents with psychosis ( = 7); 4) adults with psychosis ( = 44); and 5) relatives of a participant with psychosis ( = 20).
RESULTS
There was no significant difference in spp. IFA seroreactivity between adults with psychosis and adult controls unaffected by psychosis. There was a higher proportion of adults with psychosis who had spp. DNA in the bloodstream (43.2%) compared to adult controls unaffected by psychosis (14.3%, = 0.021). The species was determined for 18 of the 31 bacteremic participants, including infection or co-infection with (11/18), subsp. b (6/18), (2/18), (1/18), and (1/18).
DISCUSSION
In conjunction with other recent research, the results of this study provide justification for a large national or international multi-center study to determine if spp. bacteremia is more prevalent in adults with psychosis compared to adults unaffected by psychosis. Expanding the investigation to include a range of vector-borne and other microbial infections with potential CNS effects would enhance knowledge on the relationship between psychosis and infection.
PubMed: 38911703
DOI: 10.3389/fpsyt.2024.1388442 -
Industrial & Engineering Chemistry... Jun 2024Extracellular polymeric substances (EPS) are natural polymers secreted by microorganisms and represent a key chemical for the development of a range of circular economy...
Extracellular polymeric substances (EPS) are natural polymers secreted by microorganisms and represent a key chemical for the development of a range of circular economy applications. The production of EPS comes with notable challenges such as downstream processing. In this work, a three-phase partitioning (TPP) system was investigated as a fractionation technique for the separation of polysaccharides and proteins, both present in the EPS culture broth. The effect of the type of phase-forming compounds (alcohol, polymer, or ionic liquid, in combination with salt) and its concentration were evaluated and compared to the results previously obtained with model systems. The recyclability of phase-forming compounds used to form the fractionation platform was assessed by ultrafiltration. The best fractionation of EPS was achieved using a TPP system composed of 23 wt % ethanol and 25% KCHO as 82% EPS-PS partitioned to the salt-rich/bottom phase, and 76% EPS-PN was recovered as an interfacial precipitate, which could be readily resolubilized in water. This represented an increase of 1.24 and 2.83-fold in the purity of EPS-PS and EPS-PN, respectively, in relation to the initial feed concentration. Finally, high recovery yields of phase-forming compounds (>99%) and fractionated EPS (>80%) were obtained using ultrafiltration/diafiltration (UF/DF) as the regeneration technique. The substantial fractionation yields, selectivity, and recyclability of the phase-forming compounds confirm the potential of TPP systems in combination with UF/DF as the separation method for real biopolymer mixtures. Key contributions of this study include the demonstration of the applicability of a readily scalable and cost-effective separation technique for the fractionation of EPS from real EPS-containing broths, while also the limitations of prescreening with model systems became clear through the observed deviating trends between model system studies and real broth studies.
PubMed: 38911146
DOI: 10.1021/acs.iecr.4c00840 -
Synthetic and Systems Biotechnology Dec 2024Collagen XVII (COL17) is a transmembrane protein that mediates skin homeostasis. Due to expression of full length collagen was hard to achieve in microorganisms, arising...
Collagen XVII (COL17) is a transmembrane protein that mediates skin homeostasis. Due to expression of full length collagen was hard to achieve in microorganisms, arising the needs for selection of collagen fragments with desired functions for microbial biosynthesis. Here, COL17 fragments (27-33 amino acids) were extracted and replicated 16 times for recombinant expression in . Five variants were soluble expressed, with the highest yield of 223 mg/L. The fusion tag was removed for biochemical and biophysical characterization. Circular dichroism results suggested one variant (sample-1707) with a triple-helix structure at >37 °C. Sample-1707 can assemble into nanofiber (width, 5.6 nm) and form hydrogel at 3 mg/mL. Sample-1707 was shown to induce blood clotting and promote osteoblast differentiation. Furthermore, sample-1707 exhibited high capacity to induce mouse hair follicle stem cells differentiation and osteoblast migration, demonstrating a high capacity to induce skin cell regeneration and promote wound healing. A strong hydrogel was prepared from a chitosan and sample-1707 complex with a swelling rate of >30 % higher than simply using chitosan. Fed-batch fermentation of sample-1707 with a 5-L bioreactor obtained a yield of 600 mg/L. These results support the large-scale production of sample-1707 as a biomaterial for use in the skin care industry.
PubMed: 38911060
DOI: 10.1016/j.synbio.2024.06.001