RESUMEN
The ocean-atmosphere exchange of CO2 largely depends on the balance between marine microbial photosynthesis and respiration. Despite vast taxonomic and metabolic diversity among marine planktonic bacteria and archaea (prokaryoplankton)1-3, their respiration usually is measured in bulk and treated as a 'black box' in global biogeochemical models4; this limits the mechanistic understanding of the global carbon cycle. Here, using a technology for integrated phenotype analyses and genomic sequencing of individual microbial cells, we show that cell-specific respiration rates differ by more than 1,000× among prokaryoplankton genera. The majority of respiration was found to be performed by minority members of prokaryoplankton (including the Roseobacter cluster), whereas cells of the most prevalent lineages (including Pelagibacter and SAR86) had extremely low respiration rates. The decoupling of respiration rates from abundance among lineages, elevated counts of proteorhodopsin transcripts in Pelagibacter and SAR86 cells and elevated respiration of SAR86 at night indicate that proteorhodopsin-based phototrophy3,5-7 probably constitutes an important source of energy to prokaryoplankton and may increase growth efficiency. These findings suggest that the dependence of prokaryoplankton on respiration and remineralization of phytoplankton-derived organic carbon into CO2 for its energy demands and growth may be lower than commonly assumed and variable among lineages.
Asunto(s)
Organismos Acuáticos , Archaea , Bacterias , Ciclo del Carbono , Respiración de la Célula , Plancton , Alphaproteobacteria/genética , Alphaproteobacteria/crecimiento & desarrollo , Alphaproteobacteria/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/crecimiento & desarrollo , Bacterias/metabolismo , Dióxido de Carbono/metabolismo , Plancton/clasificación , Plancton/genética , Plancton/crecimiento & desarrollo , Plancton/metabolismo , Agua de Mar/microbiología , Organismos Acuáticos/clasificación , Organismos Acuáticos/genética , Organismos Acuáticos/crecimiento & desarrollo , Organismos Acuáticos/metabolismo , Archaea/genética , Archaea/crecimiento & desarrollo , Archaea/metabolismo , Respiración de la Célula/fisiología , FotosíntesisRESUMEN
An active microbial community of nitrifying and denitrifying bacteria is needed for efficient utilization of nitrogenous compounds from wastewater. In this study, we explored the bacterial community diversity and structure within rivers, treated and untreated wastewater treatment plants (WWTPs) discharging into Lake Victoria. Water samples were collected from rivers and WWTPs that drain into Lake Victoria. Physicochemical analysis was done to determine the level of nutrients or pollutant loading in the samples. Total community DNA was extracted, followed by Illumina high throughput sequencing to determine the total microbial community and abundance. Enrichment and isolation were then done to recover potential nitrifiers and denitrifiers. Physicochemical analysis pointed to high levels total nitrogen and ammonia in both treated and untreated WWTPs as compared to the samples from the lake and rivers. A total of 1,763 operational taxonomic units (OTUs) spread across 26 bacterial phyla were observed with the most dominant phylum being Proteobacteria. We observed a decreasing trend in diversity from the lake, rivers to WWTPs. The genus Planktothrix constituted 19% of the sequence reads in sample J2 collected from the lagoon. All the isolates recovered in this study were affiliated to three genera: Pseudomonas, Klebsiella and Enterobacter in the phylum Proteobacteria. A combination of metagenomic analysis and a culture-dependent approach helped us understand the relative abundance as well as potential nitrifiers and denitrifiers present in different samples. The recovered isolates could be used for in situ removal of nitrogenous compounds from contaminated wastewater.
Asunto(s)
Bacterias/crecimiento & desarrollo , Bacterias/metabolismo , Lagos , Aguas Residuales/microbiología , Purificación del Agua , Bacterias/clasificación , Bacterias/aislamiento & purificación , Desnitrificación , Enterobacter/clasificación , Enterobacter/crecimiento & desarrollo , Enterobacter/metabolismo , Kenia , Klebsiella/clasificación , Klebsiella/crecimiento & desarrollo , Klebsiella/aislamiento & purificación , Klebsiella/metabolismo , Lagos/química , Lagos/microbiología , Nitrificación , Proteobacteria/clasificación , Proteobacteria/crecimiento & desarrollo , Proteobacteria/aislamiento & purificación , Proteobacteria/metabolismo , Pseudomonas/clasificación , Pseudomonas/crecimiento & desarrollo , Pseudomonas/aislamiento & purificación , Pseudomonas/metabolismo , Ríos/microbiología , Aguas Residuales/químicaRESUMEN
Spodoptera frugiperda is a highly polyphagous pest worldwide with a wide host range that causes serious losses to many economically important crops. Recently, insect-microbe associations have become a hot spot in current entomology research, and the midgut microbiome of S. frugiperda has been investigated, while the effects of cruciferous vegetables remain unknown. In this study, the growth of S. frugiperda larvae fed on an artificial diet, Brassica campestris and Brassica oleracea for 7 days was analyzed. Besides, the microbial community and functional prediction analyses of the larval midguts of S. frugiperda fed with different diets were performed by high-throughput sequencing. Our results showed that B. oleracea inhibited the growth of S. frugiperda larvae. The larval midgut microbial community composition and structure were significantly affected by different diets. Linear discriminant analysis effect size (LEfSe) suggested 20 bacterial genera and 2 fungal genera contributed to different gut microbial community structures. The functional classification of the midgut microbiome analyzed by PICRUSt and FUNGuild showed that the most COG function categories of midgut bacterial function were changed by B. oleracea, while the guilds of fungal function were altered by B. campestris significantly. These results showed that the diversity and structure of the S. frugiperda midgut microbial community were affected by cruciferous vegetable feeding. Our study provided a preliminary understanding of the role of midgut microbes in S. frugiperda larvae in response to cruciferous vegetables.
Asunto(s)
Bacterias/clasificación , Brassica , Hongos/clasificación , Microbiota , Spodoptera/microbiología , Verduras , Animales , Bacterias/genética , Bacterias/crecimiento & desarrollo , Hongos/genética , Hongos/crecimiento & desarrollo , Larva/fisiología , MicobiomaRESUMEN
Ecotoxicity assessments based on bacteria as model organisms are widely used for routine toxicity screening because it has the advantages of time-saving, high sensitivity, cost-effectiveness, and less ethical responsibility. Determination of ecotoxicity effect via bacterial growth can avoid the restriction of model bacteria selection and unique equipment requirements, but traditional viable cell count methods are relatively labor- and time-intensive. The Start Growth Time method (SGT) is a high-throughput and time-conserving method to determine the amount of viable bacterial cells. However, its usability and stability for ecotoxicity assessment are rarely studied. This study confirmed its applicability in terms of bacterial types (gram-positive and gram-negative), growth phases (middle exponential and early stationary phases), and simultaneous existence of dead cells (adjustment by flow cytometry). Our results verified that the stability of establishing SGT correlation is independent of the bacterial type and dead-cell portion. Moreover, we only observed the effect of growth phases on the slope value of established SGT correlation in Shewanella oneidensis, which suggests that preparing inoculum for the SGT method should be consistent in keeping its stability. Our results also elucidate that the SGT values and the live cell percentages meet the non-linear exponential correlation with high correlation coefficients from 0.97 to 0.99 for all the examined bacteria. The non-linear exponential correlation facilitates the application of the SGT method in the ecotoxicity assessment. Finally, applying the exponential SGT correlation to evaluate the ecotoxicity effect of copper ions on E. coli was experimentally validated. The SGT-based method would require about 6 to 7 h to finish the assessment and obtain an estimated EC50 at 2.27 ± 0.04 mM. This study demonstrates that the exponential SGT correlation can be a high-throughput, time-conversing, and wide-applicable method for bacterial ecotoxicity assessment.
Asunto(s)
Bacterias , Técnicas Bacteriológicas , Ecotoxicología , Ecotoxicología/métodos , Ensayos Analíticos de Alto Rendimiento , Bacterias/crecimiento & desarrolloRESUMEN
Biofilm formation is an important and ubiquitous mode of growth among bacteria. Central to the evolutionary advantage of biofilm formation is cell-cell and cell-surface adhesion achieved by a variety of factors, some of which are diffusible compounds that may operate as classical public goods-factors that are costly to produce but may benefit other cells. An outstanding question is how diffusible matrix production, in general, can be stable over evolutionary timescales. In this work, using Vibrio cholerae as a model, we show that shared diffusible biofilm matrix proteins are indeed susceptible to cheater exploitation and that the evolutionary stability of producing these matrix components fundamentally depends on biofilm spatial structure, intrinsic sharing mechanisms of these components, and flow conditions in the environment. We further show that exploitation of diffusible adhesion proteins is localized within a well-defined spatial range around cell clusters that produce them. Based on this exploitation range and the spatial distribution of cell clusters, we constructed a model of costly diffusible matrix production and related these length scales to the relatedness coefficient in social evolution theory. Our results show that production of diffusible biofilm matrix components is evolutionarily stable under conditions consistent with natural biofilm habitats and host environments. We expect the mechanisms revealed in this study to be relevant to other secreted factors that operate as cooperative public goods in bacterial communities and the concept of exploitation range and the associated analysis tools to be generally applicable.
Asunto(s)
Bacterias , Matriz Extracelular de Sustancias Poliméricas , Evolución Social , Bacterias/crecimiento & desarrollo , Modelos Biológicos , Vibrio choleraeRESUMEN
Global warming is an indisputable fact. However, the effect of warming on the rhizosphere bacterial community of crops is not well understood. Therefore, we carried out pot experiments with three rice (Oryza sativa L.) varieties in black soil across three climatic regions of northeast China to simulate temperature change, and analyzed the response of the rhizosphere bacterial community to different temperatures. Results showed that climate had stronger effects on rhizosphere bacterial communities than rice variety. The rhizosphere bacterial diversity differed significantly among the three climatic regions and positively correlated with the mean daily average temperature (MAveT), mean daily maximum temperature (MMaxT), and mean daily minimum temperature (MMinT), and negatively correlated with the daily temperature range (DTR). Principal co-ordinate analysis revealed that bulk soil bacterial communities maintained a high similarity across the three climatic regions, while rhizosphere bacterial communities notably varied. This change was significantly correlated with MAveT, MMaxT, MMinT, and DTR. Compared with bulk soil, Proteobacteria and Bacteroidetes were enriched in the rhizosphere, while Actinobacteria was depleted. Moreover, these changes were strengthened by increasing the temperature and decreasing DTR. Additionally, correlation analysis revealed that changes in rhizosphere bacterial communities were closely related to the formation of rice yields. Our study revealed that the increasing temperature indirectly reshapes the rhizosphere bacterial community that may promote rice production in areas with lower temperatures.
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Bacterias , Oryza , Rizosfera , Bacterias/crecimiento & desarrollo , Oryza/microbiología , Microbiología del Suelo , TemperaturaRESUMEN
Crustin are a family of antimicrobial peptides that play an important role in protecting against pathogens infection in the innate immune system of crustaceans. Previously, we identified several novel types of crustins, including type VI and type VII crustins. However, their immune functions were still unclear. In the present study, the immune function of type VII crustin LvCrustinVII were investigated in Litopenaeus vannamei. LvCrustinVII was wildly expressed in all tested tissues, with relatively high expression levels in hepatopancreas, epidermis and lymphoid organ. Upon Vibrio parahaemolyticus infection, LvCrustinVII was significantly upregulated in hepatopancreas. Recombinant LvCrustinVII (rLvCrustinVII) showed strong inhibitory activities against Gram-negative bacteria Vibrio harveyi and V. parahaemolyticus, while weak activities against the Gram-positive bacteria Staphylococcus aureus. Binding assay showed that rLvCrustinVII could bind strongly to V. harveyi and V. parahaemolyticus, as well as the cell wall components Glu, LPS and PGN. In the presence of Ca2+, rLvCrustinVII could agglutinate V. parahaemolyticus and enhance hemocyte phagocytosis. The present data partially illustrate the immune function of LvCrustinVII, which enrich our understanding on the functional mechanisms of crustins and provide useful information for application of this kind of antimicrobial peptides.
Asunto(s)
Péptidos Catiónicos Antimicrobianos , Proteínas de Artrópodos , Proteínas Opsoninas , Penaeidae/inmunología , Aglutinación , Animales , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/inmunología , Péptidos Catiónicos Antimicrobianos/farmacología , Proteínas de Artrópodos/química , Proteínas de Artrópodos/genética , Proteínas de Artrópodos/inmunología , Proteínas de Artrópodos/farmacología , Bacterias/química , Bacterias/efectos de los fármacos , Bacterias/genética , Bacterias/crecimiento & desarrollo , Epidermis/inmunología , Hemocitos/fisiología , Hepatopáncreas/inmunología , Proteínas Opsoninas/química , Proteínas Opsoninas/genética , Proteínas Opsoninas/inmunología , Proteínas Opsoninas/farmacología , Fagocitosis , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologíaRESUMEN
An unusual sesquiterpene glycoside trichoacorside A (1) and two novel sorbicillinoid glycosides sorbicillisides A (2) and B (3), together with a known compound sorbicillin (4), were isolated and identified from the culture extract of an endophytic fungus Trichoderma longibrachiatum EN-586, obtained from the marine red alga Laurencia obtusa. Trichoacorside A (1) is the first representative of a glucosamine-coupled acorane-type sesquiterpenoid. Their structures were elucidated based on detailed interpretation of NMR and mass spectroscopic data. The absolute configurations were determined by X-ray crystallographic analysis, chemical derivatization, and DP4+ probability analysis. The antimicrobial activities of compounds 1-4 against several human, aquatic, and plant pathogens were evaluated.
Asunto(s)
Antiinfecciosos , Endófitos/química , Glicósidos , Hypocreales/química , Laurencia/microbiología , Policétidos , Resorcinoles , Sesquiterpenos , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Glicósidos/química , Glicósidos/aislamiento & purificación , Glicósidos/farmacología , Hongos Mitospóricos/efectos de los fármacos , Hongos Mitospóricos/crecimiento & desarrollo , Estructura Molecular , Policétidos/química , Policétidos/aislamiento & purificación , Policétidos/farmacología , Resorcinoles/química , Resorcinoles/aislamiento & purificación , Resorcinoles/farmacología , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Sesquiterpenos/farmacologíaRESUMEN
One new depsidone derivative, aspergillusidone H (3), along with seven known biosynthetically related chlorinated polyketides, were obtained from the Beibu Gulf coral-derived fungus Aspergillus unguis GXIMD 02505. Their structures were determined by comprehensive physicochemical and spectroscopic data interpretation. Notably, the X-ray crystal structure of 2 and the previously unknown absolute configuration of 8, assigned by ECD calculations, are described here for the first time. Compounds 1-5, 7 and 8 exhibited inhibition of lipopolysaccharide (LPS)-induced NF-κB in RAW 264.7 macrophages at 20 µM. In addition, the two potent inhibitors (2 and 7) dose-dependently suppressed RANKL-induced osteoclast differentiation without any evidence of cytotoxicity in bone marrow macrophages cells (BMMs). This is the first report of osteoclastogenesis inhibitory activity for the metabolites of these kinds. Besides, compounds 1, 2, 4, and 6-8 showed inhibitory activity against marine biofilm-forming bacteria, methicillin-resistant Staphylococcus aureus, Microbulbifer variabilis, Marinobacterium jannaschii, and Vibrio pelagius, with their MIC values ranging from 2 to 64 µg/mL. These findings provide a basis for further development of chlorinated polyketides as potential inhibitors of osteoclast differentiation and/or for use as anti-fouling agents.
Asunto(s)
Antozoos/microbiología , Antibacterianos , Aspergillus/química , Productos Biológicos , Osteogénesis/efectos de los fármacos , Policétidos , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Productos Biológicos/farmacología , Células Cultivadas , Lipopolisacáridos/farmacología , Macrófagos/citología , Macrófagos/efectos de los fármacos , Ratones , Estructura Molecular , FN-kappa B/metabolismo , Océanos y Mares , Policétidos/química , Policétidos/aislamiento & purificación , Policétidos/farmacología , Ligando RANKRESUMEN
Five undescribed butenolides including two pairs of enantiomers, (+)-asperteretal G (1a), (-)-asperteretal G (1b), (+)-asperteretal H (2a), (-)-asperteretal H (2b), asperteretal I (3), and para-hydroxybenzaldehyde derivative, (S)-3-(2,3-dihydroxy-3-methylbutyl)-4-hydroxybenzaldehyde (14), were isolated together with ten previously reported butenolides 4-13, from the coral-derived fungus Aspergillus terreus SCSIO41404. Enantiomers 1a/1b and 2a/2b were successfully purified by high performance liquid chromatography (HPLC) using a chiral column, and the enantiomers 1a and 1b were new natural products. Structures of the unreported compounds, including the absolute configurations, were elucidated by NMR and MS data, optical rotation, experimental and calculated electronic circular dichroism, induced circular dichroism, and X-ray crystal data. The isolated butenolides were evaluated for antibacterial, cytotoxic, and enzyme inhibitory activities. Compounds 7 and 12 displayed weak antibacterial activity, against Enterococcus faecalis (IC50 = 25 µg/mL) and Klebsiella pneumoniae (IC50 = 50 µg/mL), respectively, whereas 6 showed weak inhibitory effect on acetylcholinesterase. Nevertheless, most of the butenolides showed inhibition against pancreatic lipase (PL) with an inhibition rate of 21.2-73.0% at a concentration of 50 µg/mL.
Asunto(s)
4-Butirolactona/análogos & derivados , Antozoos/microbiología , Antibacterianos , Aspergillus/química , Productos Biológicos , Inhibidores de la Colinesterasa , Lipasa/antagonistas & inhibidores , 4-Butirolactona/química , 4-Butirolactona/aislamiento & purificación , 4-Butirolactona/farmacología , Acetilcolinesterasa/metabolismo , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antibacterianos/toxicidad , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Productos Biológicos/farmacología , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/aislamiento & purificación , Inhibidores de la Colinesterasa/farmacología , Estructura Molecular , EstereoisomerismoRESUMEN
Descriptions of the small intestinal microbiota are deficient and conflicting. We aimed to get a reliable description of the jejunal bacterial microbiota by investigating samples from two separate jejunal segments collected from the luminal mucosa during surgery. Sixty patients with morbid obesity selected for elective gastric bypass surgery were included in this survey. Samples collected by rubbing a swab against the mucosa of proximal and mid jejunal segments were characterized both quantitatively and qualitatively using a combination of microbial culture, a universal quantitative PCR and 16S deep sequencing. Within the inherent limitations of partial 16S sequencing, bacteria were assigned to the species level. By microbial culture, 53 patients (88.3%) had an estimated bacterial density of < 1600 cfu/ml in both segments whereof 31 (51.7%) were culture negative in both segments corresponding to a bacterial density below 160 cfu/ml. By quantitative PCR, 46 patients (76.7%) had less than 104 bacterial genomes/ml in both segments. The most abundant and frequently identified species by 16S deep sequencing were associated with the oral cavity, most often from the Streptococcus mitis group, the Streptococcus sanguinis group, Granulicatella adiacens/para-adiacens, the Schaalia odontolytica complex and Gemella haemolysans/taiwanensis. In general, few bacterial species were identified per sample and there was a low consistency both between the two investigated segments in each patient and between patients. The jejunal mucosa of fasting obese patients contains relatively few microorganisms and a core microbiota could not be established. The identified microbes are likely representatives of a transient microbiota and there is a high degree of overlap between the most frequently identified species in the jejunum and the recently described ileum core microbiota.
Asunto(s)
Bacterias/crecimiento & desarrollo , Microbioma Gastrointestinal , Mucosa Intestinal/microbiología , Yeyuno/microbiología , Obesidad Mórbida/microbiología , Adulto , Anciano , Bacterias/genética , ADN Bacteriano/genética , Femenino , Derivación Gástrica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mucosa Intestinal/cirugía , Yeyuno/cirugía , Masculino , Persona de Mediana Edad , Obesidad Mórbida/diagnóstico , Obesidad Mórbida/cirugía , Reacción en Cadena en Tiempo Real de la Polimerasa , Ribotipificación , Adulto JovenRESUMEN
Evidence highlights the comorbidity between emotional distress and irritable bowel syndrome (IBS) through the gut-brain axis. However, the underlying mechanism is largely unknown. Thus, the present study aimed to evaluate the associations among neurotransmitter levels and the gut microbiome profiles in persons with IBS and emotional distress. In this nested case-controlled study, emotional symptoms, including anxiety and depressive symptoms, were evaluated in 40 persons with IBS and 20 healthy controls (HC). Plasma neurotransmitters levels (serotonin and norepinephrine) and the gut microbiome profile of the collected fecal samples were examined. Emotional distress and microbiome profile were significantly different between IBS and HC groups. Lower but not significant neurotransmitters' levels (serotonin and norepinephrine) were observed in the IBS group compared to the HC. A negative correlation was found between norepinephrine levels and alpha diversity (Shannon and Simpson indices) in the IBS group. Moreover, serotonin levels were positively associated with the abundance of Proteobacteria, and norepinephrine were positively correlated with Bacteroidetes, but negatively associated with Firmicutes phylum. The present study demonstrated alteration in the gut microbiome between persons with IBS and emotional distress compared to HC. The correlations between plasma neurotransmitters and the gut microbiome suggest that the gut microbiome may impact the regulation of neurotransmitters.
Asunto(s)
Bacterias/crecimiento & desarrollo , Eje Cerebro-Intestino , Microbioma Gastrointestinal , Tracto Gastrointestinal/microbiología , Síndrome del Colon Irritable/sangre , Síndrome del Colon Irritable/microbiología , Norepinefrina/sangre , Distrés Psicológico , Serotonina/sangre , Bacterias/metabolismo , Estudios de Casos y Controles , Estudios Transversales , Disbiosis , Heces/microbiología , Femenino , Humanos , Síndrome del Colon Irritable/psicología , Masculino , Ensayos Clínicos Controlados Aleatorios como Asunto , Adulto JovenRESUMEN
Spent coffee grounds (SCGs), which constitute 75% of original coffee beans, represent an integral part of sustainability. Contamination by toxigenic fungi and their mycotoxins is a hazard that threatens food production. This investigation aimed to examine SCGs extract as antimycotic and anti-ochratoxigenic material. The SCGs were extracted in an eco-friendly way using isopropanol. Bioactive molecules of the extract were determined using the UPLC apparatus. The cytotoxicity on liver cancer cells (Hep-G2) showed moderate activity with selectivity compared with human healthy oral epithelial (OEC) cell lines but still lower than the positive control (Cisplatin). The antibacterial properties were examined against pathogenic strains, and the antifungal was examined against toxigenic fungi using two diffusion assays. Extract potency was investigated by two simulated models, a liquid medium and a food model. The results of the extract showed 15 phenolic acids and 8 flavonoids. Rosmarinic and syringic acids were the most abundant phenolic acids, while apigenin-7-glucoside, naringin, epicatechin, and catechin were the predominant flavonoids in the SCGs extract. The results reflected the degradation efficiency of the extract against the growth of Aspergillus strains. The SCGs recorded detoxification in liquid media for aflatoxins (AFs) and ochratoxin A (OCA). The incubation time of the extract within dough spiked with OCA was affected up to 2 h, where cooking was not affected. Therefore, SCGs in food products could be applied to reduce the mycotoxin contamination of raw materials to the acceptable regulated limits.
Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Café , Flavonoides/farmacología , Fenoles/farmacología , Residuos , Aflatoxinas/química , Aflatoxinas/metabolismo , Antibacterianos/química , Antifúngicos/química , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Flavonoides/química , Contaminación de Alimentos/prevención & control , Hongos/efectos de los fármacos , Hongos/crecimiento & desarrollo , Hongos/metabolismo , Humanos , Ocratoxinas/química , Ocratoxinas/metabolismo , Fenoles/químicaRESUMEN
Antimony (Sb), a global and priority controlled pollutant, causes severe environmental issues. Bioremediation by microbial communities containing sulfate-reducing bacteria (SRB) is considered to be among the safest, economical, and environmentally friendly methods to remove Sb from wastewater. However, the roles of SRB species in these communities remain uncertain, and pure cultures of bacteria that may be highly efficient have not yet been developed for Sb removal. In this study, an Sb tolerant community was enriched from municipal sludge, and molecular ecological analysis showed that Escherichia (40%) and Desulfovibrio (15%) were the dominant bacteria. Further isolation and identification showed that the enriched SRB strains were closely related to Cupidesulfovibrio oxamicus, based on the molecular analyses of 16S rRNA and dsrB genes. Among them, a strain named SRB49 exhibited the highest activity in removal of Sb(V). SRB49 was able to remove 95% of Sb(V) at a concentration of 100 mg/L within 48 h under optimum conditions: a temperature of 37-40 °C, an initial pH value of 8, 4 mM of sulfate, and an initial redox potential of 145-229 mV. SEM-EDX analysis showed that SRB49 did not adsorb Sb(V) but reduced and precipitated Sb(V) via the formation of Sb2S3. The results demonstrated the potential roles that pure cultures of SRB species may play in Sb removal and the use of Sb-tolerant SRB strains for Sb remediation.
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Antimonio/análisis , Bacterias/clasificación , Aguas del Alcantarillado/microbiología , Aguas Residuales/microbiología , Bacterias/genética , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Biodegradación Ambiental , Ciudades , Secuenciación de Nucleótidos de Alto Rendimiento , Oxidación-Reducción , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Sulfatos/química , Aguas Residuales/químicaRESUMEN
Nutrient dynamics function globally, flowing from rivers to the ocean (estuarine-coastal zone), and are vulnerable to climate change. Microbial habitats can be affected by marine nutrient dynamics and may provide a clue to predict microbial responses to environmental heterogeneity in estuarine-coastal zones. We surveyed surface seawater in Gwangyang Bay, a semi-enclosed estuary in Korea, from 2016 to 2018 using a metabarcoding approach with prokaryotic 16S and eukaryotic 18S rRNA genes. Bacterial and microeukaryotic communities in these waters showed distinct local communities in response to environmental heterogeneity and community transition at spatiotemporal scales in the estuarine-coastal zone. The relative abundance of prokaryotic and eukaryotic operational taxonomic units suggested a microbial trophic interaction in the Gwangyang Bay waters. We found that the community assembly process in prokaryotic communities was primarily influenced by biological interaction (immigration-emigration), whereas that in eukaryotic communities was more affected by environmental stress (habitat specificity) rather than by biotic factors. Our findings in the Gwangyang Bay waters may provide information on underlying (biotic or abiotic) factors of the assembly process in microbial communities in the estuarine-coastal zone.
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Bahías/microbiología , Biodiversidad , Eucariontes , Filogenia , Plancton , Agua de Mar/microbiología , Bacterias/clasificación , Bacterias/genética , Bacterias/crecimiento & desarrollo , Eucariontes/clasificación , Eucariontes/genética , Eucariontes/crecimiento & desarrollo , Plancton/clasificación , Plancton/genética , Plancton/crecimiento & desarrollo , ARN Ribosómico 16S/genética , ARN Ribosómico 18S/genética , República de CoreaRESUMEN
The gastrointestinal tract represents one of the largest body surfaces that is exposed to the outside world. It is the only mucosal surface that is required to simultaneously recognize and defend against pathogens, while allowing nutrients containing foreign antigens to be tolerated and absorbed. It differentiates between these foreign substances through a complex system of pattern recognition receptors expressed on the surface of the intestinal epithelial cells as well as the underlying immune cells. These immune cells actively sample and evaluate microbes and other particles that pass through the lumen of the gut. This local sensing system is part of a broader distributed signaling system that is connected to the rest of the body through the enteric nervous system, the immune system, and the metabolic system. While local tissue homeostasis is maintained by commensal bacteria that colonize the gut, colonization itself may not be required for the activation of distributed signaling networks that can result in modulation of peripheral inflammation. Herein, we describe the ability of a gut-restricted strain of commensal bacteria to drive systemic anti-inflammatory effects in a manner that does not rely upon its ability to colonize the gastrointestinal tract or alter the mucosal microbiome. Orally administered EDP1867, a gamma-irradiated strain of Veillonella parvula, rapidly transits through the murine gut without colonization or alteration of the background microbiome flora. In murine models of inflammatory disease including delayed-type hypersensitivity (DTH), atopic dermatitis, psoriasis, and experimental autoimmune encephalomyelitis (EAE), treatment with EDP1867 resulted in significant reduction in inflammation and immunopathology. Ex vivo cytokine analyses revealed that EDP1867 treatment diminished production of pro-inflammatory cytokines involved in inflammatory cascades. Furthermore, blockade of lymphocyte migration to the gut-associated lymphoid tissues impaired the ability of EDP1867 to resolve peripheral inflammation, supporting the hypothesis that circulating immune cells are responsible for promulgating the signals from the gut to peripheral tissues. Finally, we show that adoptively transferred T cells from EDP1867-treated mice inhibit inflammation induced in recipient mice. These results demonstrate that an orally-delivered, non-viable strain of commensal bacteria can mediate potent anti-inflammatory effects in peripheral tissues through transient occupancy of the gastrointestinal tract, and support the development of non-living bacterial strains for therapeutic applications.
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Antibacterianos/farmacología , Bacterias/inmunología , Citocinas/metabolismo , Microbioma Gastrointestinal/efectos de los fármacos , Inflamación/inmunología , Animales , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Células Epiteliales/efectos de los fármacos , Femenino , Humanos , Inmunidad Mucosa , Inflamación/etiología , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Simbiosis , Linfocitos T/metabolismoRESUMEN
According to the latest report released by the World Health Organization, bacterial resistance to well-known and widely available antibacterial drugs has become a significant and severe global health concern and a grim challenge to tackle in order to cure infections associated with multidrug-resistant pathogenic microorganisms efficiently. Consequently, various strategies have been orchestrated to cure the severe complications related to multidrug-resistant bacteria effectively. Some approaches involved the retardation of biofilm formation and multidrug-resistance pumps in bacteria as well as the discovery of new antimicrobial agents demonstrating different mechanisms of action. In this regard, natural products namely alkaloids, terpenoids, steroids, anthraquinone, flavonoids, saponins, tannins, etc., have been suggested to tackle the multidrug-resistant bacterial strains owing to their versatile pharmacological effects. Amongst these, flavonoids, also known as polyphenolic compounds, have been widely evaluated for their antibacterial property due to their tendency to retard the growth of a wide range of pathogenic microorganisms, including multidrug-resistant bacteria. The hydroxylation of C5, C7, C3', and C4'; and geranylation or prenylation at C6 have been extensively studied to increase bacterial inhibition of flavonoids. On the other hand, methoxylation at C3' and C5 has been reported to decrease flavonoids' antibacterial action. Hence, the latest information on the antibacterial activity of flavonoids is summarized in this review, with particular attention to the structure-activity relationship of this broad class of natural compounds to discover safe and potent antibacterial agents as natural products.
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Antibacterianos , Bacterias/crecimiento & desarrollo , Infecciones Bacterianas/tratamiento farmacológico , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Flavonoides , Antibacterianos/química , Antibacterianos/uso terapéutico , Flavonoides/química , Flavonoides/uso terapéutico , Relación Estructura-ActividadRESUMEN
This research aims to investigate the synthesis, characterization, and evaluation of the biocompatibility and antibacterial activity of novel zinc oxide (ZnO) nanoparticles (NPs) prepared by Punica granatum peel and coffee ground extracts as the reducing and capping agents. Chemically synthesized ZnONPs were prepared using zinc acetate dihydrate and sodium hydroxide as reducing precursors. ZnONPs were characterized using an ultraviolet-visible spectrophotometer (UV-VIS), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared (FTIR) spectroscopy. Peaks of UV spectra were 300 nm for ZnONPs_PPE, 320 nm (ZnONPs_CE), 290 nm, and 440 nm (ZnONP_Chem), thereby confirming ZnONPs formation. The X-ray diffractograms revealed their hexagonal structure. TEM micrographs of the biosynthesized ZnONPs revealed their hexagonal pattern and nanorod shape for ZnONPs_Chem with particle sizes of 118.6 nm, 115.7 nm, and 111.2 nm, respectively. The FTIR analysis demonstrated the presence of proteins, carboxyl, and hydroxyl groups on ZnONPs surfaces that act as reducing and stabilizing agents. ZnONP_Chem shows the antibacterial effect on Staphylococcus aureus, Enterobacter aerogenes, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Punica peel and coffee ground extracts are effective reducing agents for green ZnONPs synthesis with a lower cytotoxic effect on Vero cells than ZnONPs_Chem with IC50 = 111, 103, and 93 µg/mL, respectively.
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Antibacterianos , Bacterias/crecimiento & desarrollo , Café/química , Frutas/química , Ensayo de Materiales , Nanopartículas/química , Granada (Fruta)/química , Óxido de Zinc , Animales , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Chlorocebus aethiops , Células Vero , Óxido de Zinc/química , Óxido de Zinc/farmacologíaRESUMEN
In our attempt towards the synthesis and development of effective antimicrobial, anticancer and antioxidant agents, a novel series of 2,3-dihydropyrido[2,3-d]pyrimidin-4-one 7a-e and pyrrolo[2,1-b][1,3]benzothiazoles 9a-e were synthesized. The synthesis of 2-(1,3-benzo thiazol-2-yl)-3-(aryl)prop-2-enenitrile (5a-e) as the key intermediate was accomplished by a microwave efficient method. Via a new variety oriented synthetic microwave pathway, these highly functionalized building blocks allowed access to numerous fused heteroaromatic such as 7-amino-6-(1,3-benzo thiazol-2-yl)-5-(aryl)-2-thioxo-2,3dihydropyrido [2,3-d]pyrimidin-4(1H)-one 7a-e and 1-amino-2-(aryl)pyrrolo[2,1-b][1,3]benzothiazole-3-carbonitrile derivatives 9a-e in order to study their antimicrobial and anticancer activity. The present investigation offers effective and rapid new procedures for the synthesis of the newly polycondensed heterocyclic ring systems. All the newly synthesized compounds were evaluated for antimicrobial, anticancer and antioxidant activity. Compounds 7a,d, and 9a,d showed higher antimicrobial activity than cefotaxime and fluconazole while the remaining compounds exhibited good to moderate activity against bacteria and fungi. An anticancer evaluation of the newly synthesized compounds against the three tumor cell lines (lung cell NCI-H460, liver cancer HepG2 and colon cancer HCT-116) exhibited that compounds 7a, d, and 9a,d have higher cytotoxicity against the three human cell lines compared to doxorubicin as a reference drug. These compounds also exhibited higher antioxidant activity and a great ability to protect DNA from damage induced by bleomycin.
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Antiinfecciosos , Antineoplásicos , Antioxidantes , Benzotiazoles , Microondas , Antiinfecciosos/síntesis química , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Antioxidantes/síntesis química , Antioxidantes/química , Antioxidantes/farmacología , Bacterias/crecimiento & desarrollo , Benzotiazoles/síntesis química , Benzotiazoles/química , Benzotiazoles/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Hongos/crecimiento & desarrollo , Células HCT116 , Células Hep G2 , Humanos , Pruebas de Sensibilidad MicrobianaRESUMEN
Marine microalgae and cyanobacteria are sources of diverse bioactive compounds with potential biotechnological applications in food, feed, nutraceutical, pharmaceutical, cosmetic and biofuel industries. In this study, five microalgae, Nitzschia sp. S5, Nanofrustulum shiloi D1, Picochlorum sp. D3, Tetraselmis sp. Z3 and Tetraselmis sp. C6, and the cyanobacterium Euhalothece sp. C1 were isolated from the Adriatic Sea and characterized regarding their growth kinetics, biomass composition and specific products content (fatty acids, pigments, antioxidants, neutral and polar lipids). The strain Picochlorum sp. D3, showing the highest specific growth rate (0.009 h-1), had biomass productivity of 33.98 ± 0.02 mg L-1 day-1. Proteins were the most abundant macromolecule in the biomass (32.83-57.94%, g g-1). Nanofrustulum shiloi D1 contained significant amounts of neutral lipids (68.36%), while the biomass of Picochlorum sp. D3, Tetraselmis sp. Z3, Tetraselmis sp. C6 and Euhalothece sp. C1 was rich in glycolipids and phospholipids (75%). The lipids of all studied microalgae predominantly contained unsaturated fatty acids. Carotenoids were the most abundant pigments with the highest content of lutein and neoxanthin in representatives of Chlorophyta and fucoxanthin in strains belonging to the Bacillariophyta. All microalgal extracts showed antioxidant activity and antimicrobial activity against Gram-negative E. coli and S. typhimurium and Gram-positive S. aureus.
