Phosphorus clusters
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Upon phosphorus (P) deficiency, marine phytoplankton reduce their requirements for P by replacing membrane phospholipids with alternative non-phosphorus lipids. It was very recently demonstrated that a SAR11 isolate also shares this capability when phosphate starved in culture. Yet, the extent to which this process occurs in other marine heterotrophic bacteria and in the natural environment is unknown. Here, we demonstrate that the substitution of membrane phospholipids for a variety of non-phosphorus lipids is a conserved response to P deficiency among phylogenetically diverse marine heterotrophic bacteria, including members of the Alphaproteobacteria and Flavobacteria. By deletion mutagenesis and complementation in the model marine bacterium Phaeobacter sp. MED193 and heterologous expression in recombinant Escherichia coli, we confirm the roles of a phospholipase C (PlcP) and a glycosyltransferase in lipid remodelling. Analyses of the Global Ocean Sampling and Tara Oceans metagenome data sets demonstrate that PlcP is particularly abundant in areas characterized by low phosphate concentrations. Furthermore, we show that lipid remodelling occurs seasonally and responds to changing nutrient conditions in natural microbial communities from the Mediterranean Sea. Together, our results point to the key role of lipid substitution as an adaptive strategy enabling heterotrophic bacteria to thrive in the vast P-depleted areas of the ocean.
- MeSH
- Alphaproteobacteria metabolismus MeSH
- fosfáty chemie MeSH
- fosfolipasy metabolismus MeSH
- fosfolipidy chemie MeSH
- fosfor chemie MeSH
- fylogeneze MeSH
- fytoplankton metabolismus MeSH
- glykosyltransferasy metabolismus MeSH
- heterotrofní procesy MeSH
- mikrobiologie vody MeSH
- mořská voda mikrobiologie MeSH
- oceány a moře MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- oceány a moře MeSH
- Středozemní moře MeSH
Due to insufficient amount of soluble phosphate and poor persistence of traditional chemical phosphate fertilizers in agricultural soils, the eco-friendly and sustainable phosphorus sources for crops are urgently required. The efficient phosphate-releasing fungal strain designated y2 was isolated and identified by the internal transcribed spacer of rDNA as Penicillium oxalicum y2. When lecithin, Ca3(PO4)2, or ground phosphate rock were separately used as sole phosphorus source, different phosphate-releasing modes were observed. The strain y2 was able to release as high as 2090 mg/L soluble phosphate within 12 days of incubation with Ca3(PO4)2 as sole phosphorus source. In the culture solution, high concentration of oxalic, citric, and malic acids and high phosphatase activity were detected. The organic acids contributed to solubilizing inorganic phosphate sources, while phosphatase was in charge of the mineralization of organic phosphorus lecithin. Afterwards, the fungus culture was applied to the soil with rape growing. During 50 days of incubation, the soil's available phosphate concentration increased by three times compared with the control, the dry weight of rape increased by 78.73%, and the root length increased by 38.79%. The results illustrated that P. oxalicum y2 possessed both abilities of solubilizing inorganic phosphorus and mineralizing organic phosphorus, which have great potential application in providing biofertilizer for modern agriculture.
- MeSH
- biologická dostupnost MeSH
- Brassica napus růst a vývoj MeSH
- dusík metabolismus MeSH
- fosfatasy metabolismus MeSH
- fosfáty metabolismus farmakokinetika MeSH
- fosfor metabolismus MeSH
- fylogeneze MeSH
- kyseliny karboxylové metabolismus MeSH
- mezerníky ribozomální DNA genetika MeSH
- Penicillium klasifikace genetika izolace a purifikace metabolismus MeSH
- půda chemie MeSH
- půdní mikrobiologie * MeSH
- uhlík metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Phosphorus nitride clusters generated during Laser Desorption Ionization (LDI) and Matrix-Assisted Laser Desorption Ionization (MALDI) of solid P(3) N(5) were analyzed via Time-of-Flight Mass Spectrometry (TOF MS). The LDI TOF mass spectra show the formation of series of clusters: P(m)N(n)(+) {(m=1; n=8-11), (m=4; n=3-4), (m=5; n=1-5), (m=6; n=1-3, 5-8), (m=2-7; n=1), (m=5-10; n=2), (m=4-6; n=3), (m=4,5; n=4), (m=5,6; n=5)}, and P(m)N(n)(-) (m=4,5; n=1). Using 3-hydroxypicolinic acid (HPA) as a matrix the P(m)N(n)(+) species (m=1-4, 6, 8) with a high nitrogen content (n=4, 5, 8, 10-12, 20) were identified. The formation of a N(6)(-) cluster was also detected using a C(60) matrix. Under various conditions singly charged P(m)(+) (m=2-7, 9, 13), P(m)(-) (m=3-11, 13, 15, 17), N(n)(+) (n=5, 9, 10, 12, 13), and N(n)(-) (n=6, 10-15) clusters were identified in the mass spectra. Such high nitrogen content clusters (up to N(15)(-)) generated by laser desorption from a solid material are described for the first time. The stoichiometry of the P(m)N(n) clusters was determined via isotopic envelope analysis and computer modelling. The composition of the clusters with respect to the crystalline structure of α-P(3)N(5) is discussed.
- Publikační typ
- časopisecké články MeSH
Lake Medard is an oligotrophic post-mining lake characterised by ferruginous bottom waters, with marked redox gradients resulting from iron (Fe) and nitrogen (N) speciation and accompanying depth-dependent variations in the abundance of volatile fatty acids (VFAs), pH and alkalinity. The lacustrine system is meromictic, featuring a dysoxic hypolimnion and an anoxic monimolimnion with relatively high concentrations of sulfate (SO42-, 19 ± 2 mM) and Fe(ii) (127 ± 17 μM). An increase in dissolved manganese is also observed with increasing depth, together with a general lack of sulfide, which can only be detected at the sediment-water interface at concentrations of ∼0.30 μM. In the hypolimnion, nitrate (NO3-) becomes progressively depleted and ammonium (NH4+) dominates the dissolved N inventory (up to 185 ± 13 μM). Here we describe the biogeochemical disequilibrium conditions governing critical mineralogical transformations involving Fe and phosphorus (P) co-precipitation in the dysoxic-to-anoxic bottom water column. A combination of mineral equilibrium modelling and synchrotron-based diffraction and spectroscopic techniques was applied to investigate the minerals comprising the upper anoxic sediments. The combined dataset indicates that elemental recycling on and below the hypolimnion promote the precipitation of FeOOH polymorphs that accumulate as heterogeneous mineral clusters. Changes in the relative abundance of bacterioplankton taxa with increasing water depth point to a link between the activity of certain members of Proteobacteria and the co-recycling of carbon (C), N, and Fe stocks. Such a redox recycling process seems to lead to P stabilisation into organic-rich Fe-(oxyhydr)oxides near and above the anoxic sediment-water interface (SWI).
- MeSH
- dusík MeSH
- ekosystém * MeSH
- fosfor chemie MeSH
- geologické sedimenty chemie MeSH
- hornictví MeSH
- jezera chemie mikrobiologie MeSH
- koloběh dusíku MeSH
- mangan chemie MeSH
- minerály MeSH
- oxidace-redukce MeSH
- plankton MeSH
- sírany MeSH
- sulfidy chemie MeSH
- uhlík chemie MeSH
- vodní organismy MeSH
- železo chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
The distribution of the phylogenetically narrow R-BT065 cluster (Betaproteobacteria) in 102 freshwater lakes, reservoirs, and various ponds located in central Europe (a total of 122 samples) was examined by using a cluster-specific fluorescence in situ hybridization probe. These habitats differ markedly in pH, conductivity, trophic status, surface area, altitude, bedrock type, and other limnological characteristics. Despite the broad ecological diversity of the habitats investigated, the cluster was detected in 96.7% of the systems, and its occurrence was not restricted to a certain habitat type. However, the relative proportions of the cluster in the total bacterioplankton were significantly lower in humic and acidified lakes than in pH-neutral or alkaline habitats. On average, the cluster accounted for 9.4% of the total bacterioplankton (range, 0 to 29%). The relative abundance and absolute abundance of these bacteria were significantly and positively related to higher pH, conductivity, and the proportion of low-molecular-weight compounds in dissolved organic carbon (DOC) and negatively related to the total DOC and dissolved aromatic carbon contents. Together, these parameters explained 55.3% of the variability in the occurrence of the cluster. Surprisingly, no clear relationship of the R-BT065 bacteria to factors indicating the trophic status of habitats (i.e., different forms of phosphorus and chlorophyll a content) was found. Based on our results and previously published data, we concluded that the R-BT065 cluster represents a ubiquitous, highly active segment of bacterioplankton in nonacidic lakes and ponds and that alga-derived substrates likely form the main pool of substrates responsible for its high growth potential and broad distribution in freshwater habitats.
- MeSH
- Betaproteobacteria klasifikace genetika izolace a purifikace MeSH
- chlorofyl analýza MeSH
- DNA bakterií chemie MeSH
- ekosystém MeSH
- Eukaryota genetika MeSH
- fosfor analýza MeSH
- fylogeneze MeSH
- genetická variace MeSH
- hybridizace in situ fluorescenční MeSH
- mikrobiologie vody MeSH
- nadmořská výška MeSH
- počet mikrobiálních kolonií MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 16S genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- skleníkový efekt MeSH
- sladká voda chemie mikrobiologie MeSH
- uhlík analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
Mineral nutrition of crop plants is one of the major challenges faced by modern agriculture, particularly in arid and semi-arid regions. In alkaline calcareous soils, the availability of phosphorus and zinc is critically less due to their fixation and precipitation as complexes. Farmers use fertilizers to fulfill crop requirements, but their efficacy is less, which increases production costs. Plant growth-promoting rhizobacteria (PGPR) can improve the availability of crop nutrients through solubilizing the insoluble compounds of phosphorus and zinc in soil. In the present study, a total of 40 rhizobacterial isolates were isolated from cotton rhizosphere and screened for improving cotton growth through the solubilization of phosphorus and zinc. Out of these 40 isolates, seven isolates (IA2, IA3, IA6, IA7, IA8, IA13, and IA14) efficiently solubilized insoluble rock phosphate while seven isolates (IA10, IA16, IA20, IA23, IA24, IA28, and IA30) were more efficient in solubilizing insoluble zinc oxide. In liquid media, strain IA7 (2.75 μg/mL) solubilized the highest amount of phosphate while the highest concentration of soluble zinc was observed in the broth inoculated with strain IA20 (3.94 μg/mL). Seven phosphate-solubilizing and seven zinc-solubilizing strains were evaluated using jar trial to improve the growth of cotton seedlings, and the results were quite promising. All the inoculated treatments showed improvement in growth parameters in comparison with control. Best results were shown by the combined application of IA6 and IA16, followed by the combination of strains IA7 and IA20. Based on the jar trial, the selected isolates were further characterized by plant growth-promoting characters such as siderophores production, HCN production, ammonia production, and exopolysaccharides production. These strains were identified through 16S rRNA sequencing as Bacillus subtilis IA6 (accession # MN005922), Paenibacillus polymyxa IA7 (accession # MN005923), Bacillus sp. IA16 (accession # MN005924), and Bacillus aryabhattai IA20 (accession # MN005925). It is hence concluded that the integrated use of phosphate-solubilizing and zinc-solubilizing strains as potential inoculants can be a promising approach for improving cotton growth under semi-arid conditions.
- MeSH
- Bacillus klasifikace genetika izolace a purifikace metabolismus MeSH
- fosfáty metabolismus MeSH
- fosfor metabolismus MeSH
- fylogeneze MeSH
- Gossypium růst a vývoj mikrobiologie MeSH
- očkovadla agrotechnická klasifikace genetika izolace a purifikace metabolismus MeSH
- Paenibacillus polymyxa klasifikace genetika izolace a purifikace metabolismus MeSH
- půda chemie MeSH
- půdní mikrobiologie MeSH
- rhizosféra MeSH
- RNA ribozomální 16S genetika MeSH
- zinek metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Although phosphine is ubiquitously present in anaerobic environments, little is known regarding the microbial community dynamics and metabolic pathways associated with phosphine formation in an anaerobic digestion system. This study investigated the production of phosphine in anaerobic digestion, with results indicating that phosphine production mainly occurred during logarithmic microbial growth. Dehydrogenase and hydrogen promoted the production of phosphine, with a maximum phosphine concentration of 300 mg/m3. The abundance of Ruminococcaceae and Escherichia was observed to promote phosphine generation. The analysis of metabolic pathways based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the MetaCyc pathway database revealed the highest relative abundance of replication and repair in genetic information processing; further, the cofactor, prosthetic group, electron carrier, and vitamin biosynthesis were observed to be closely related to phosphine formation. A phylogenetic tree was reconstructed based on the neighbor-joining method. The results indicated the clear evolutionary position of the isolated Pseudescherichia sp. SFM4 strain, adjacent to Escherichia, with a stable phosphate-reducing ability for a maximum phosphine concentration of 26 mg/m3. The response surface experiment indicated that the initial optimal conditions for phosphine production by SFM4 could be achieved with nitrogen, carbon, and phosphorus loads of 6.17, 300, and 10 mg/L, respectively, at pH 7.47. These results provide comprehensive insights into the dynamic changes in the microbial structure, isolated single bacterial strain, and metabolic pathways associated with phosphine formation. They also provide information on the molecular biology associated with phosphorus recycling.
- MeSH
- anaerobióza MeSH
- bioreaktory mikrobiologie MeSH
- Clostridiales genetika metabolismus MeSH
- dusík metabolismus MeSH
- Escherichia genetika metabolismus MeSH
- fosfáty metabolismus MeSH
- fosfiny analýza metabolismus MeSH
- fosfor metabolismus MeSH
- fylogeneze MeSH
- metabolické sítě a dráhy * genetika MeSH
- mikrobiota * MeSH
- odpadní vody mikrobiologie MeSH
- vodík metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Plant variation in nutrient concentrations encompasses two major axes. The first is connected to nitrogen (N) and phosphorus (P), reflects growth rate and has been designated as the leaf economics spectrum (LES) while the second follows the gradient in calcium (Ca) and magnesium (Mg) and mirrors cell structural differences. Here, we tested in grasslands whether the sum Ca + Mg concentrations is a better indicator of digestibility than LES constituents. Structural equation modelling revealed that the total effect size of N (0.30) on digestibility was much lower than that of Ca + Mg (0.58). The N effect originated predominantly from sampling date (biomass ageing), while the Ca + Mg effect largely from phylogenetic composition (proportion of monocots). Thus, plant variation in partially substitutable divalent cations seems to play a significant role in biomass digestion by ruminants. This finding contests, together with litter decomposition studies, the prominent role of the LES for understanding both fundamental ecological processes.
In the past few decades, the pressure of higher food production to satisfy the demand of ever rising population has inevitably increased the use synthetic agrochemicals which have deterioration effects. Biostimulants containing beneficial microbes (single inoculants and microbial consortium) were found as an ideal substitute of synthetic chemical fertilizers. In recent years, microbial consortium is known as a better bioinoculant in comparison to single inoculant bioformulation because of multifarious plant growth-promoting advantages. Looking at the advantageous effect of consortium, in present investigation, different bacteria were isolated from rhizospheric soil and plant samples collected from the Himalayan mountains on the green slopes of the Shivaliks, Himachal Pradesh. The isolated bacteria were screened for nitrogen (N) fixation, phosphorus (P) solubilization and potassium (K) solubilization plant growth promoting attributes, and efficient strains were identified through 16S rRNA gene sequencing and BLASTn analysis. The bacteria showing a positive effect in NPK uptake were developed as bacterial consortium for the growth promotion of eggplant crop. A total of 188 rhizospheric and endophytic bacteria were sorted out, among which 13 were exhibiting nitrogenase activity, whereas 43 and 31 were exhibiting P and K solubilization traits, respectively. The selected three efficient and potential bacterial strains were identified using 16S rRNA gene sequencing as Enterobacter ludwigii EU-BEN-22 (N-fixer; 35.68 ± 00.9 nmol C2H4 per mg protein per h), Micrococcus indicus EU-BRP-6 (P-solubilizer; 201 ± 0.004 mg/L), and Pseudomonas gessardii EU-BRK-55 (K-solubilizer; 51.3 ± 1.7 mg/mL), and they were used to develop a bacterial consortium. The bacterial consortium evaluation on eggplant resulted in the improvement of growth (root/shoot length and biomass) and physiological parameters (chlorophyll, carotenoids, total soluble sugar, and phenolic content) of the plants with respect to single culture inoculation, chemical fertilizer, and untreated control. A bacterial consortium having potential to promote plant growth could be used as bioinoculant for horticulture crops growing in hilly regions.
- MeSH
- Bacteria * genetika klasifikace metabolismus izolace a purifikace růst a vývoj MeSH
- draslík metabolismus MeSH
- dusík metabolismus MeSH
- fixace dusíku * MeSH
- fosfor * metabolismus MeSH
- fylogeneze MeSH
- kořeny rostlin mikrobiologie MeSH
- mikrobiální společenstva * MeSH
- půdní mikrobiologie * MeSH
- rhizosféra MeSH
- RNA ribozomální 16S * genetika MeSH
- Solanum melongena * mikrobiologie MeSH
- vývoj rostlin MeSH
- Publikační typ
- časopisecké články MeSH
