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Frontiers in Microbiology 2021As the unique component of , dendrobine-type sesquiterpenoid alkaloids (DSAs) possess a variety of medicinal properties. It has been well documented that plant...
As the unique component of , dendrobine-type sesquiterpenoid alkaloids (DSAs) possess a variety of medicinal properties. It has been well documented that plant endophytes can synthesize secondary metabolites identical or similar to metabolites produced by their host plants. This study aimed to investigate the composition and distribution of endophytic bacteria of stems by Illumina MiSeq platform sequencing and cultivation-dependent methods and then to assess the potential for endophytic bacteria to produce DSAs. Results indicated that it was necessary to combine both cultivation-dependent and cultivation-independent methods to analyze the community structure of endophytic bacterial in plants comprehensively. The length of the stems influenced the endophytic bacterial community. The diversity and richness of endophytic bacteria in group J10_15cm of stems were the highest, which showed a significant difference from the other stem groups. However, there was no certain connection between the diversity and richness of endophytic bacteria and the content of dendrobine. It was most likely due to the influence of several specific endophytic bacteria genera, such as and . , , as pathogenic fungi, and subsp. , as pathogenic bacteria of , were used to determine the antimicrobial activities. In these assays, six strains belonging to five genera showed antimicrobial activity against at least two phytopathogens. The strain BL-YJ10_15-29 ( THG-N2.35, 98.98%) showed the best antimicrobial activity against the three phytopathogens. In addition, 2 DSAs (6-hydroxydendrobine and nobilonine) were identified in the fermentation supernatant of the strain CM-YJ10_15-44 ( CHA0, 99.24%), whereas the whole-genome analysis results further demonstrated that the precursors of the two DSAs [geranyl-PP and (E, E)-famesyl-PP] were synthesized mainly through the methyl-D-erythritol 4-phosphate pathway in this strain. This study provides new insight into the studies on the biosynthesis of DSAs and provides potential biocontrol bacteria.
PubMed: 35069479
DOI: 10.3389/fmicb.2021.775665 -
ACS Sustainable Chemistry & Engineering Jul 2021Polyhydroxyalkanoates (PHAs) are versatile biodegradable polymers produced by bacteria and are suitable for many downstream applications. They can be produced...
Polyhydroxyalkanoates (PHAs) are versatile biodegradable polymers produced by bacteria and are suitable for many downstream applications. They can be produced inexpensively from mixed microbial cultures under feast and famine conditions in the presence of biobased volatile fatty acids (VFAs). Here, we investigated the effect of changing the sludge retention time (SRT) and the addition of fermented cellulosic primary sludge (CPS) as a carbon source on the selection of PHA-storing biomass when applying the feast and famine strategy under aerobic and anoxic conditions, respectively. Increasing the SRT from 5 to 7-10 days enhanced PHA yields under feast conditions from 0.18 gCOD/gCOD (period 1) to 0.40 gCOD/gCOD (period 2). The use of fermented CPS as a carbon source (period 3) increased PHA yields to 0.62 gCOD/gCOD despite the presence of biodegradable non-VFA fractions. Microbial characterization by denaturing gradient gel electrophoresis and fluorescence in situ hybridization revealed high microbial speciation during the three experimental periods. In period 3, the dominant genera were , , and , which accounted for ∼95% of the total microbial biomass.
PubMed: 35059238
DOI: 10.1021/acssuschemeng.1c02973 -
Journal of Immunology Research 2021To conduct a preliminary investigation that shows the possible correlation between the change of gut microbiota and missed abortions (MAs), which further provides a new...
OBJECTIVE
To conduct a preliminary investigation that shows the possible correlation between the change of gut microbiota and missed abortions (MAs), which further provides a new potential insight for the prevention and therapy of MAs.
METHOD
One hundred women, including 50 patients with MAs (case group) and 50 normal pregnant women (control group), were enrolled in the study. Fecal specimens were collected in the first trimester. Bacterial DNA was extracted, hybridized with primers of specific genes, and then detected by bacterial chip. The composition and the relative abundance of the gut microbiota were compared and analyzed. Furthermore, Kyoto Encyclopedia of Genes and Genomes enrichment analysis was used to explore the relative pathways.
RESULTS
(1) The -diversity and -diversity of the gut microbiota in patients with MAs were significantly lower than that those in normal pregnant women ( < 0.05). At the phylum level, , , , and accounted for the main proportion of intestinal flora in the 2 groups. Only was high in the case group. Significant differences were found between the two groups at the phylum level ( < 0.05). , , and were significantly more abundant in the control group than in the case group at the genus level ( < 0.05). (2) KEGG pathway enrichment analysis found significant differences in 27 signaling pathways and metabolic pathways between the two groups of differentially expressed genes (all adjusted < 0.05). (3) The positive rate of (MH) detection in the control group was significantly higher in the MA group ( = 7.853, = 0.004).
CONCLUSION
The high abundance of in the MA group was the first time found and reported in the study. The dysbiosis of the gut microbiota correlates with MAs. This study provided insights into the potential change of gut microbiota of MAs and the potential underlying mechanisms through certain impaired lipid metabolism and aroused inflammation pathways. Comprehensive insights regarding gut microbiota may facilitate improved understanding and the development of novel therapeutic and preventive strategies for MAs.
Topics: Abortion, Missed; Adult; Biodiversity; China; Computational Biology; Disease Susceptibility; Dysbiosis; Female; Gastrointestinal Microbiome; Humans; Metagenomics; Mycoplasma; Pregnancy; Risk Factors
PubMed: 34966824
DOI: 10.1155/2021/5571894 -
Journal of Nematology 2021Using the approach of sequencing the V3-V4 region of the 16S rRNA gene, we have analyzed the bacterial diversity associated with the gut and "body" (other parts of...
Using the approach of sequencing the V3-V4 region of the 16S rRNA gene, we have analyzed the bacterial diversity associated with the gut and "body" (other parts of nematode after dissection: cuticle, epidermis and longitudinal muscles, etc) of parasitizing the swim bladder of different morphotypes of the nosed charr. Comparisons of the gut microbiota of nematodes with their "body" has revealed that the associated microbiota are closely related to each other. Taxonomic analysis indicated that the relative abundances of the dominant nematode-associated bacteria varied with individual fish. The common dominant microbiota of the gut and "body" of nematodes were represented by , , , and , while the associated microbiota of the swim bladder of the nosed charr was dominated by , , , , , . By comparing the associated microbiota of nematode parasitizing the different morphotypes of the nosed charr the difference in richness estimates (number of OTU's and Chao1) were revealed between the N1g and N2 morphs.
PubMed: 34957411
DOI: 10.21307/jofnem-2021-106 -
Microorganisms Nov 2021Human living environments and health are seriously affected by the odor produced from fermentation of livestock and poultry manure. In order to reduce the odor pollution...
Human living environments and health are seriously affected by the odor produced from fermentation of livestock and poultry manure. In order to reduce the odor pollution caused by livestock and poultry manure, efficient strains were screened and two methods were tried in this study. The orthogonal test design was used to analyze the gas produced by pig manure under different conditions of temperature, time, wheat straw doping amount and calcium carbonate doping amount. Then, according to ammonia, hydrogen sulfide and comprehensive odor removal effects, the high efficiency of deodorizing strains were screened. The results showed that pig manure produced the least odor when the temperature was 20 °C, added 0% calcium carbonate, 20% wheat straw and waited for 48 h. Three strains were screened to inhibit the odor production of pig manure: , and , showed that their highest removal rate of ammonia and hydrogen sulfide gas could reach 96.58% and 99.74% among them; while for three strains of end-control pig manure stench: , and , the highest removal rate of ammonia and hydrogen sulfide gas reached 85.91% and 90.80% among them. This research provides bacteria resources as the high-efficiency deodorizing function for the source suppression and the end treatment of the odor gas of pig manure, which has high application value for the control of odor pollution.
PubMed: 34946090
DOI: 10.3390/microorganisms9122488 -
Antibiotics (Basel, Switzerland) Dec 2021Mangrove plant endophytic bacteria are prolific sources of bioactive secondary metabolites. In the present study, twenty-three endophytic bacteria were isolated from the...
Mangrove plant endophytic bacteria are prolific sources of bioactive secondary metabolites. In the present study, twenty-three endophytic bacteria were isolated from the fresh roots of the mangrove plant . The identification of isolates by 16S rRNA gene sequences revealed that the isolated endophytic bacteria belonged to nine genera, including , , , , , , , , and . The ethyl acetate extracts of the endophytic bacteria's pharmacological properties were evaluated in vitro, including antimicrobial, antioxidant, α-amylase and α-glucosidase inhibitory, xanthine oxidase inhibitory, and cytotoxic activities. Gas chromatography-mass spectrometry (GC-MS) analyses of three high bioactive strains sp. RAR_GA_16, RAR_WA_32, and sp. RAR_M1_44 identified major volatile organic compounds (VOCs) in their ethyl acetate extracts. Genome analyses identified biosynthesis gene clusters (BGCs) of secondary metabolites of the bacterial endophytes. The obtained results reveal that the endophytic bacteria from may be a potential source of pharmacological secondary metabolites, and further investigations of the high bioactive strains-such as fermentation and isolation of pure bioactive compounds, and heterologous expression of novel BGCs in appropriate expression hosts-may allow exploring and exploiting the promising bioactive compounds for future drug development.
PubMed: 34943703
DOI: 10.3390/antibiotics10121491 -
The Science of the Total Environment Mar 2022Growth conditions have been frequently studied in optimizing polyhydroxybutyrate (PHB) production, while few studies were performed to unravel the dynamic mixed...
Growth conditions have been frequently studied in optimizing polyhydroxybutyrate (PHB) production, while few studies were performed to unravel the dynamic mixed microbial consortia (MMCs) in the process. In this study, the relationship between growth conditions (C/N ratios and pH) and the corresponding key-microbes were identified and monitored during PHB accumulation. The highest PHB level (70 wt% of dry cell mass) was obtained at pH 9, C/N 40, and acetic acid 10 g/L. Linking the dominant genera with the highest point of PHB accumulation, Thauera was the most prevalent species in all MMCs of pH 9, except when a C/N ratio of 1 was applied. Notably, dominant bacteria shifted at pH 7 (C/N 10) from Thauera (0 h) to Paracoccus, and subsequently to Alcaligenes following the process of PHB accumulation and consumption. Further understanding of the relationship between the structure of the microbial community and the performance will be beneficial for regulating and obtaining high PHB accumulation within an MMC. Our study illustrates the impact of C/N ratios and pH on microbial prevalence and PHB production levels using a mixed microbial starter culture. This knowledge will broaden industrial perspectives for regulating high PHB production and timely harvesting.
Topics: Carbon; Hydrogen-Ion Concentration; Microbial Consortia; Nitrogen; Prevalence
PubMed: 34921889
DOI: 10.1016/j.scitotenv.2021.152341 -
Frontiers in Microbiology 2021Harmful algal blooms caused by frequently occur worldwide and severely threaten the marine environment. In this study, the biochemical and physiological responses of...
Harmful algal blooms caused by frequently occur worldwide and severely threaten the marine environment. In this study, the biochemical and physiological responses of to the algicidal bacterium O-4 were investigated, and the effects on the levels of reactive oxygen species (ROS), malondialdehyde content, multiple antioxidant systems and metabolites, photosynthetic pigments, and photosynthetic index were examined. The cell-free supernatant in strain O-4 significantly inhibited cell growth. The bacterium caused the cells to activate their antioxidant defenses to mitigate ROS, and this effect was accompanied by the upregulation of intracellular antioxidant enzymes and non-enzyme systems. However, the overproduction of ROS induced lipid peroxidation and oxidative damage within cells, ultimately leading to algal death. In addition, the photosynthetic efficiency of the algal cells was significantly inhibited by O-4 and was accompanied by a reduction in photosynthetic pigments. This study indicates that O-4 inhibits through excessive oxidative stress and impaired photosynthesis. This research into the biochemical and physiological responses of to algicidal bacteria provides insights into the prophylaxis and control of harmful algal blooms interactions between harmful algae and algicidal bacteria.
PubMed: 34917053
DOI: 10.3389/fmicb.2021.771381 -
Nature Communications Nov 2021Cytochrome c oxidases are among the most important and fundamental enzymes of life. Integrated into membranes they use four electrons from cytochrome c molecules to...
Cytochrome c oxidases are among the most important and fundamental enzymes of life. Integrated into membranes they use four electrons from cytochrome c molecules to reduce molecular oxygen (dioxygen) to water. Their catalytic cycle has been considered to start with the oxidized form. Subsequent electron transfers lead to the E-state, the R-state (which binds oxygen), the P-state (with an already split dioxygen bond), the F-state and the O-state again. Here, we determined structures of up to 1.9 Å resolution of these intermediates by single particle cryo-EM. Our results suggest that in the O-state the active site contains a peroxide dianion and in the P-state possibly an intact dioxygen molecule, the F-state may contain a superoxide anion. Thus, the enzyme's catalytic cycle may have to be turned by 180 degrees.
Topics: Catalysis; Cryoelectron Microscopy; Electron Transport Complex IV; Electrons; Escherichia coli; Membrane Proteins; Models, Molecular; Oxygen; Paracoccus denitrificans; Peroxides; Protons
PubMed: 34824221
DOI: 10.1038/s41467-021-27174-y -
MicrobiologyOpen Nov 2021The bacterial communities of Caulerpa lentillifera were studied during an outbreak of an unknown disease in a sea grape farm from Vietnam. Clear differences between...
The bacterial communities of Caulerpa lentillifera were studied during an outbreak of an unknown disease in a sea grape farm from Vietnam. Clear differences between healthy and diseased cases were observed at the order, genus, and Operational Taxonomic Unit (OTU) level. A richer diversity was detected in the diseased thalli of C. lentillifera, as well as the dominance of the orders Flavobacteriales (phylum Bacteroidetes) and Phycisphaerales (Planctomycetes). Aquibacter, Winogradskyella, and other OTUs of the family Flavobacteriaceae were hypothesized as detrimental bacteria, this family comprises some well-known seaweed pathogens. Phycisphaera together with other Planctomycetes and Woeseia were probably saprophytes of C. lentillifera. The Rhodobacteraceae and Rhodovulum dominated the bacterial community composition of healthy C. lentillifera. The likely beneficial role of Bradyrhizobium, Paracoccus, and Brevundimonas strains on nutrient cycling and phytohormone production was discussed. The bleaching of diseased C. lentillifera might not only be associated with pathogens but also with an oxidative response. This study offers pioneering insights on the co-occurrence of C. lentillifera-attached bacteria, potential detrimental or beneficial microbes, and a baseline for understanding the C. lentillifera holobiont. Further applied and basic research is urgently needed on C. lentillifera microbiome, shotgun metagenomic, metatranscriptomic, and metabolomic studies as well as bioactivity assays are recommended.
Topics: Bacteria; Bacterial Physiological Phenomena; Caulerpa; Host Microbial Interactions; Microbiota; Plant Diseases
PubMed: 34821475
DOI: 10.1002/mbo3.1253