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Foods (Basel, Switzerland) Jul 2023In order to investigate and develop functional foods of marine origin with hypoglycemic activity, polysaccharide-Zn(II) (EZ) complex was first prepared by marine...
In order to investigate and develop functional foods of marine origin with hypoglycemic activity, polysaccharide-Zn(II) (EZ) complex was first prepared by marine resourced polysaccharide (EP) and ZnSO and their anti-diabetes activities against high-sugar and high-fat-induced diabetic mice were evaluated. The detailed structural characterization of EZ was elucidated by UV-Vis spectroscopy, infrared spectroscopy, and monosaccharide composition determination. The pharmacological research suggests that EZ has a potent hypoglycemic effect on high-sugar and high-fat-induced diabetic mice by inhibiting insulin resistance, improving dyslipidemia, decreasing inflammatory status, repairing pancreas damage, as well as activating the IRS/PI3K/AKT signaling pathway and regulating GLUT2 gene expression. At the same time, microbiota analysis indicates that a high dose of EZ could enhance the abundance of dominant species, such as , , , , and , in intestinal microbiota distribution. Thus, EZ could be considered as a potential candidate for developing an ingredient of functional foods for Zn(II) supplements with hypoglycemic activity.
PubMed: 37569125
DOI: 10.3390/foods12152854 -
Astrobiology Nov 2019Extraterrestrial environments encompass physicochemical conditions and habitats that are unknown on Earth, such as perchlorate-rich brines that can be at least...
Extraterrestrial environments encompass physicochemical conditions and habitats that are unknown on Earth, such as perchlorate-rich brines that can be at least temporarily stable on the martian surface. To better understand the potential for life in these cold briny environments, we determined the maximum salt concentrations suitable for growth (MSCg) of six different chloride and perchlorate salts at 25°C and 4°C for the extremotolerant cold- and salt-adapted bacterial strain . Growth was measured through colony-forming unit (CFU) counts, while cellular and colonial phenotypic stress responses were observed through visible light, fluorescence, and scanning electron microscopy. Our data show the following: (1) The tolerance to high salt concentrations can be increased through a stepwise inoculation toward higher concentrations. (2) Ion-specific factors are more relevant for the growth limitation of in saline solutions than single physicochemical parameters like ionic strength or water activity. (3) shows the highest microbial sodium perchlorate tolerance described so far. However, (4) MSCg values are higher for all chlorides compared to perchlorates. (5) The MSCg for calcium chloride was increased by lowering the temperature from 25°C to 4°C, while sodium- and magnesium-containing salts can be tolerated at 25°C to higher concentrations than at 4°C. (6) Depending on salt type and concentration, cells show distinct phenotypic stress responses such as novel types of colony morphology on agar plates and biofilm-like cell clustering, encrustation, and development of intercellular nanofilaments. This study, taken in context with previous work on the survival of extremophiles in Mars-like environments, suggests that high-concentrated perchlorate brines on Mars might not be habitable to any present organism on Earth, but extremophilic microorganisms might be able to evolve thriving in such environments.
Topics: Chlorides; Cold Temperature; Cold-Shock Response; Extraterrestrial Environment; Extreme Environments; Extremophiles; Mars; Osmolar Concentration; Perchlorates; Planococcaceae; Salt Stress; Salts
PubMed: 31386567
DOI: 10.1089/ast.2019.2069 -
Microorganisms Dec 2023In an attempt to isolate new probiotic bacteria, two Gram-variable, spore-forming, rod-shaped aerobic bacteria designated as strain A4 and A15 were isolated from the...
In an attempt to isolate new probiotic bacteria, two Gram-variable, spore-forming, rod-shaped aerobic bacteria designated as strain A4 and A15 were isolated from the feces of Canada geese (). Strain A4 was able to grow in high salt levels and exhibited lipase activity, while A15 did not propagate under these conditions. Both were positive for starch hydrolysis, and they inhibited the growth of . The strains of the 16S rRNA sequence shared only 94% similarity to previously identified spp. The ANI (78.08%) and AAI (82.35%) between the two strains were less than the species threshold. Searches for the most similar genomes using the Mash/Minhash algorithm showed the nearest genome to strain A4 and A15 as sp. P13 (distance of 21%) and (distance of 17%), respectively. spp. strains A4 and A15 contain urease genes, and a fibronectin-binding protein gene indicates that these bacteria may bind to eukaryotic cells in host gastrointestinal tracts. Phenotypic and phylogenetic data, along with low dDDH, ANI, and AAI values for strains A4 and A15, indicate these bacteria are two novel isolates of the genus: sp. A4 sp. nov., type strain as and sp. A15 sp. nov., type strain .
PubMed: 38257897
DOI: 10.3390/microorganisms12010070 -
Marine Drugs Mar 2021With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals'...
With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals' health. Marine probiotics, which live under high pressure in a saltwater environment, show high potential as a substitute for antibiotics in the field of aquatic disease control. In this study, twenty strains of non-hemolytic bacteria were isolated from the intestine of wild oysters and perch, and a model of infected by was established. Based on the model, ML1206, which showed a 99% similarity of 16S rRNA sequence to , was selected as a potential marine probiotic, with strong antibacterial capabilities and great acid and bile salt tolerance, to protect from being damaged by . Combined with plate counting and transmission electron microscopy, it was found that strain ML1206 could significantly inhibit colonization in the intestinal tract of . Acute oral toxicity tests in mice showed that ML1206 was safe and non-toxic. The real-time qPCR results showed a higher expression level of genes related to the antibacterial peptide () and detoxification (, , and ) in the group of protected by ML1206 compared to the control group. It is speculated that ML1206, as a potential probiotic, may inhibit the infection caused by through stimulating to secrete antibacterial effectors and detoxification proteins. This paper provides a new direction for screening marine probiotics and an experimental basis to support the potential application of ML1206 as a marine probiotic in aquaculture.
Topics: Animals; Aquaculture; Caenorhabditis elegans; Female; Intestines; Male; Mice; Mice, Inbred ICR; Ostreidae; Planococcaceae; Probiotics; RNA, Ribosomal, 16S; Survival; Vibrio; Vibrio Infections
PubMed: 33809116
DOI: 10.3390/md19030150 -
Genes Jun 2021Biogeochemical cycling of phosphorus in the agro-ecosystem is mediated by soil microbes. These microbes regulate the availability of phosphorus in the soil. Little is...
Biogeochemical cycling of phosphorus in the agro-ecosystem is mediated by soil microbes. These microbes regulate the availability of phosphorus in the soil. Little is known about the response of functional traits of phosphorus cycling microbes in soil fertilized with compost manure (derived from domestic waste and plant materials) or inorganic nitrogen fertilizers at high and low doses. We used a metagenomics investigation study to understand the changes in the abundance and distribution of microbial phosphorus cycling genes in agricultural farmlands receiving inorganic fertilizers (120 kg N/ha, 60 kg N/ha) or compost manure (8 tons/ha, 4 tons/ha), and in comparison with the control. Soil fertilization with high level of compost (Cp8) or low level of inorganic nitrogen (N1) fertilizer have nearly similar effects on the rhizosphere of maize plants in promoting the abundance of genes involved in phosphorus cycle. Genes such as involved in polyphosphate formation and (for phosphate transportation) are highly enriched in these treatments. These genes facilitate phosphorus immobilization. At a high dose of inorganic fertilizer application or low compost manure treatment, the phosphorus cycling genes were repressed and the abundance decreased. The bacterial families and were very abundant in the high inorganic fertilizer (N2) treated soil, while , , , , , , were most abundant in Cp8. , , and fungi were observed to be dominant in Cp8 and , , , and archaea have the highest percentage occurrence in Cp8. Moreover, N2 treatment, , and were most abundant among fertilized soils. Our findings have brought to light the basis for the manipulation of rhizosphere microbial communities and their genes to improve availability of phosphorus as well as phosphorus cycle regulation in agro-ecosystems.
Topics: Agriculture; Bacteria; Bacterial Proteins; Fertilizers; Manure; Metagenomics; Nitrogen; Phosphorus; Rhizosphere; Soil; Soil Microbiology; Zea mays
PubMed: 34209356
DOI: 10.3390/genes12071022 -
Ecotoxicology and Environmental Safety Dec 2021Serious hexavalent chromium [Cr(VI)] pollution has continuously threatened ecological security and public health. Microorganism-assisted remediation technology has...
Serious hexavalent chromium [Cr(VI)] pollution has continuously threatened ecological security and public health. Microorganism-assisted remediation technology has strong potential in the treatment of environmental Cr(VI) pollution due to its advantages of high efficiency, low cost, and low secondary pollution. Sporosarcina saromensis M52, a strain with strong Cr(VI) removal ability, isolated from coastal intertidal zone was used in this study. Scanning electron microscopy coupled with energy dispersive X-ray analysis indicated M52 was relatively stable under Cr(VI) stress and trace amount of Cr deposited on the cell surface. X-ray photoelectron spectroscopy and X-ray diffraction analyses exhibited M52 could reduce Cr(VI) into Cr(III). Fourier transform infrared spectroscopy showed the bacterial surface was mainly consisted of polysaccharides, phosphate groups, carboxyl groups, amide II (NH/CN) groups, alkyl groups, and hydroxyl groups, while functional groups involving in Cr(VI) bio-reduction were not detected. According to these characterization analyses, the removal of Cr(VI) was primarily depended on bio-reduction, instead of bio-adsorption by M52. Genome analyses further indicated the probable mechanisms of bio-reduction, including the active efflux of Cr(VI) by chromate transporter ChrA, enzymatic redox reactions mediated by reductases, DNA-repaired proteases ability to minimize the ROS damage, and the formation of specific cell components to minimize the biofilm injuries caused by Cr(VI). These studies provided a theoretical basis which was useful for Cr(VI) remediation, especially in terms of increasing its effectiveness. THE MAIN FINDING OF THE WORK: M52 realized the bioremediation of Cr(VI) majorly through bio-reduction, including Cr(VI) efflux, chromate reduction, DNA repair, and the formation of specific cell components, instead of bio-adsorption.
Topics: Chromium; Genomics; Sporosarcina
PubMed: 34507039
DOI: 10.1016/j.ecoenv.2021.112767 -
Microbiology Spectrum Dec 2023Since 1988, through the United States government's founding, the National Center for Biotechnology Information (NCBI) has provided an invaluable service to scientific...
Since 1988, through the United States government's founding, the National Center for Biotechnology Information (NCBI) has provided an invaluable service to scientific advancement. The universality and total freedom of use if on the one hand allow the use of this database on a global level by all researchers for their valuable work, on the other hand, it has the disadvantage of making it difficult to check the correctness of all the materials present. It is, therefore, of fundamental importance for the correctness and ethics of research to improve the databases at our disposal, identifying and amending the critical issues. This work aims to provide the scientific community with a new sequence for the type strain SK 55 and broaden the knowledge of the species, in particular, considering the ancient strain Aquil_B6 found in an ancient Roman amphora.
Topics: United States; DNA, Bacterial; Bacillaceae; Planococcaceae
PubMed: 37975675
DOI: 10.1128/spectrum.00686-23 -
Microbiology Spectrum Jun 2024The Atacama Desert is the oldest and driest desert on Earth, encompassing great temperature variations, high ultraviolet radiation, drought, and high salinity, making it...
The Atacama Desert is the oldest and driest desert on Earth, encompassing great temperature variations, high ultraviolet radiation, drought, and high salinity, making it ideal for studying the limits of life and resistance strategies. It is also known for harboring a great biodiversity of adapted life forms. While desertification is increasing as a result of climate change and human activities, it is necessary to optimize soil and water usage, where stress-resistant crops are possible solutions. As many studies have revealed the great impact of the rhizobiome on plant growth efficiency and resistance to abiotic stress, we set up to explore the rhizospheric soils of and desert plants. By culturing these soils and using 16S rRNA amplicon sequencing, we address community taxonomy composition dynamics, stability through time, and the ability to promote lettuce plant growth. The rhizospheric soil communities were dominated by the families Pseudomonadaceae, Bacillaceae, and Planococcaceae for and Porphyromonadaceae and Haloferacaceae for . Nonetheless, the cultures were completely dominated by the Enterobacteriaceae family (up to 98%). Effectively, lettuce plants supplemented with the cultures showed greater size and biomass accumulation. We identified 12 candidates that could be responsible for these outcomes, of which 5 ( and ) were part of the built co-occurrence network. We aim to contribute to the efforts to characterize the microbial communities as key for the plant's survival in extreme environments and as a possible source of consortia with plant growth promotion traits aimed at agricultural applications.IMPORTANCEThe current scenario of climate change and desertification represents a series of incoming challenges for all living organisms. As the human population grows rapidly, so does the rising demand for food and natural resources; thus, it is necessary to make agriculture more efficient by optimizing soil and water usage, thus ensuring future food supplies. Particularly, the Atacama Desert (northern Chile) is considered the most arid place on Earth as a consequence of geological and climatic characteristics, such as the naturally low precipitation patterns and high temperatures, which makes it an ideal place to carry out research that seeks to aid agriculture in future conditions that are predicted to resemble these scenarios. Our main interest lies in utilizing microorganism consortia from plants thriving under extreme conditions, aiming to promote plant growth, improve crops, and render "unsuitable" soils farmable.
Topics: Desert Climate; Soil Microbiology; Rhizosphere; Bacteria; RNA, Ribosomal, 16S; Plant Development; Lactuca; Microbiota; Soil; Biodiversity; Chenopodiaceae
PubMed: 38687070
DOI: 10.1128/spectrum.00056-24 -
Nucleic Acids Research Apr 2021Argonaute proteins are programmable nucleases that are found in both eukaryotes and prokaryotes and provide defense against invading genetic elements. Although some...
Argonaute proteins are programmable nucleases that are found in both eukaryotes and prokaryotes and provide defense against invading genetic elements. Although some prokaryotic argonautes (pAgos) were shown to recognize RNA targets in vitro, the majority of studied pAgos have strict specificity toward DNA, which limits their practical use in RNA-centric applications. Here, we describe a unique pAgo nuclease, KmAgo, from the mesophilic bacterium Kurthia massiliensis that can be programmed with either DNA or RNA guides and can precisely cleave both DNA and RNA targets. KmAgo binds 16-20 nt long 5'-phosphorylated guide molecules with no strict specificity for their sequence and is active in a wide range of temperatures. In bacterial cells, KmAgo is loaded with small DNAs with no obvious sequence preferences suggesting that it can uniformly target genomic sequences. Mismatches between the guide and target sequences greatly affect the efficiency and precision of target cleavage, depending on the mismatch position and the nature of the reacting nucleic acids. Target RNA cleavage by KmAgo depends on the formation of secondary structure indicating that KmAgo can be used for structural probing of RNA. These properties of KmAgo open the way for its use for highly specific nucleic acid detection and cleavage.
Topics: Argonaute Proteins; Bacterial Proteins; DNA, Bacterial; Planococcaceae; Protein Binding; RNA, Bacterial; Substrate Specificity
PubMed: 33744962
DOI: 10.1093/nar/gkab182 -
The ISME Journal Jan 2021Enrichment of protective microbiota in the rhizosphere facilitates disease suppression. However, how the disruption of protective rhizobacteria affects disease...
Enrichment of protective microbiota in the rhizosphere facilitates disease suppression. However, how the disruption of protective rhizobacteria affects disease suppression is largely unknown. Here, we analyzed the rhizosphere microbial community of a healthy and diseased tomato plant grown <30-cm apart in a greenhouse at three different locations in South Korea. The abundance of Gram-positive Actinobacteria and Firmicutes phyla was lower in diseased rhizosphere soil (DRS) than in healthy rhizosphere soil (HRS) without changes in the causative Ralstonia solanacearum population. Artificial disruption of Gram-positive bacteria in HRS using 500-μg/mL vancomycin increased bacterial wilt occurrence in tomato. To identify HRS-specific and plant-protective Gram-positive bacteria species, Brevibacterium frigoritolerans HRS1, Bacillus niacini HRS2, Solibacillus silvestris HRS3, and Bacillus luciferensis HRS4 were selected from among 326 heat-stable culturable bacteria isolates. These four strains did not directly antagonize R. solanacearum but activated plant immunity. A synthetic community comprising these four strains displayed greater immune activation against R. solanacearum and extended plant protection by 4 more days in comparison with each individual strain. Overall, our results demonstrate for the first time that dysbiosis of the protective Gram-positive bacterial community in DRS promotes the incidence of disease.
Topics: Actinobacteria; Bacillus; Bacteria; Firmicutes; Incidence; Solanum lycopersicum; Planococcaceae; Plant Diseases; Ralstonia solanacearum; Rhizosphere; Soil Microbiology
PubMed: 33028974
DOI: 10.1038/s41396-020-00785-x