Redox-active antibiotics enhance phosphorus bioavailability

Science ◽  
2021 ◽  
Vol 371 (6533) ◽  
pp. 1033-1037 ◽  
Author(s):  
Darcy L. McRose ◽  
Dianne K. Newman
Keyword(s):  
Iron Oxides ◽  
Microbial Growth ◽  
Antibiotic Production ◽  
Phosphorus Limitation ◽  
Redox Cycling ◽  
Reductive Dissolution ◽  
Phosphorus Acquisition ◽  
Redox Active ◽  
Life On Earth

Microbial production of antibiotics is common, but our understanding of their roles in the environment is limited. In this study, we explore long-standing observations that microbes increase the production of redox-active antibiotics under phosphorus limitation. The availability of phosphorus, a nutrient required by all life on Earth and essential for agriculture, can be controlled by adsorption to and release from iron minerals by means of redox cycling. Using phenazine antibiotic production by pseudomonads as a case study, we show that phenazines are regulated by phosphorus, solubilize phosphorus through reductive dissolution of iron oxides in the lab and field, and increase phosphorus-limited microbial growth. Phenazines are just one of many examples of phosphorus-regulated antibiotics. Our work suggests a widespread but previously unappreciated role for redox-active antibiotics in phosphorus acquisition and cycling.

scholarly journals SHIMMER (1.0): a novel mathematical model for microbial and biogeochemical dynamics in glacier forefield ecosystems

2015 ◽  
Vol 8 (10) ◽  
pp. 3441-3470 ◽  
Author(s):  
J. A. Bradley ◽  
A. M. Anesio ◽  
J. S. Singarayer ◽  
M. R. Heath ◽  
S. Arndt
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Microbial Growth ◽  
Model Development ◽  
Biogeochemical Cycling ◽  
Biogeochemical Model ◽  
Model Parameters ◽  
Glacier Forefield ◽  
Unconstrained Model

Abstract. SHIMMER (Soil biogeocHemIcal Model for Microbial Ecosystem Response) is a new numerical modelling framework designed to simulate microbial dynamics and biogeochemical cycling during initial ecosystem development in glacier forefield soils. However, it is also transferable to other extreme ecosystem types (such as desert soils or the surface of glaciers). The rationale for model development arises from decades of empirical observations in glacier forefields, and enables a quantitative and process focussed approach. Here, we provide a detailed description of SHIMMER, test its performance in two case study forefields: the Damma Glacier (Switzerland) and the Athabasca Glacier (Canada) and analyse sensitivity to identify the most sensitive and unconstrained model parameters. Results show that the accumulation of microbial biomass is highly dependent on variation in microbial growth and death rate constants, Q10 values, the active fraction of microbial biomass and the reactivity of organic matter. The model correctly predicts the rapid accumulation of microbial biomass observed during the initial stages of succession in the forefields of both the case study systems. Primary production is responsible for the initial build-up of labile substrate that subsequently supports heterotrophic growth. However, allochthonous contributions of organic matter, and nitrogen fixation, are important in sustaining this productivity. The development and application of SHIMMER also highlights aspects of these systems that require further empirical research: quantifying nutrient budgets and biogeochemical rates, exploring seasonality and microbial growth and cell death. This will lead to increased understanding of how glacier forefields contribute to global biogeochemical cycling and climate under future ice retreat.

scholarly journals Competitive exclusion and metabolic dependency among microorganisms structure the cellulose economy of agricultural soil

2020 ◽  
Author(s):  
Roland C Wilhelm ◽  
Charles Pepe-Ranney ◽  
Pamela Weisenhorn ◽  
Mary Lipton ◽  
Daniel H. Buckley
Keyword(s):  
Microbial Growth ◽  
Competitive Exclusion ◽  
Antibiotic Production ◽  
Growth Dynamics ◽  
Soil Disturbance ◽  
Gliding Motility ◽  
Cellulolytic Microorganisms ◽  
Trade Offs ◽  
Self Sufficiency ◽  
Attachment Structures

Abstract Many cellulolytic microorganisms degrade cellulose through extracellular processes that yield free intermediates which promote interactions with non-cellulolytic organisms. We hypothesize that these interactions determine the ecological and physiological traits that govern the fate of cellulosic carbon (C) in soil. We evaluated the genomic potential of soil microorganisms that access C from 13 C-labeled cellulose. We used metagenomic-SIP and metaproteomics to evaluate whether cellulolytic and non-cellulolytic microbes that access 13 C from cellulose encode traits indicative of metabolic dependency or competitive exclusion. The most highly 13 C-enriched taxa were cellulolytic Cellvibrio ( Gammaproteobacteria ) and Chaetomium ( Ascomycota ), which exhibited a strategy of self-sufficiency (prototrophy), rapid growth, and competitive exclusion via antibiotic production. These ruderal taxa were common indicators of soil disturbance in agroecosystems, such as tillage and fertilization. Auxotrophy was more prevalent in cellulolytic Actinobacteria than in cellulolytic Proteobacteria , demonstrating differences in dependency among cellulose degraders. Non-cellulolytic taxa that accessed 13 C from cellulose ( Planctomycetales , Verrucomicrobia and Vampirovibrionales ) were highly dependent, as indicated by patterns of auxotrophy and 13 C-labeling (i.e. partial labelling or labeling at later-stages). Major 13 C-labeled cellulolytic microbes ( e.g. Sorangium, Actinomycetales, Rhizobiales and Caulobacteraceae ) possessed adaptations for surface colonization ( e.g. gliding motility, hyphae, attachment structures) signifying the importance of surface ecology in decomposition. These results suggest that access to cellulose was accompanied by ecological trade-offs characterized by differing degrees of metabolic dependency and competitive exclusion. These trade-offs likely influence microbial growth dynamics on particulate organic carbon and reveal that the fate of carbon is governed by a complex economy within the microbial community.

scholarly journals Evaluation of Magnetic Separation Efficiency on a Cassiterite-Bearing Skarn Ore by Means of Integrative SEM-Based Image and XRF–XRD Data Analysis

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 390 ◽  
Author(s):  
Markus Buchmann ◽  
Edgar Schach ◽  
Raimon Tolosana-Delgado ◽  
Thomas Leißner ◽  
Jennifer Astoveza ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Iron Oxides ◽  
Separation Efficiency ◽  
Analysis Data ◽  
Gangue Mineral ◽  
Data Partition ◽  
Local Regression ◽  
Separation Processes ◽  
Magnetic Separator

Image analysis data obtained from scanning electron microscopy provided data for a detailed evaluation of the separation efficiency for various processes involving the beneficiation of particulate materials. A dry magnetic separation by a drum type magnetic separator served as a case study to visualize effects of processing of a skarn ore with a high content of cassiterite as ore mineral (~4 wt%). For this material, iron oxides and silicates are the main gangue mineral groups. Based on the obtained data, partition curves were generated with the help of local regression. From the partition curves, the separation efficiency was evaluated and the relevant particle properties deduced. A detailed analysis of the bias of the quantitative mineralogical data is presented. This bias was monitored and further analyzed in detail. Thorough analysis of feed and products of magnetic separation enabled identification of the most important factors that control losses of cassiterite to the magnetic product, namely the association with iron oxides and particle sizes below ~40 µm. The introduced methodology is a general approach applicable for the optimization of different separation processes and is not limited to the presented case study.

Enrichment of chalcophile elements in seawater accompanying the end-Cretaceous impact event

2020 ◽  
Vol 132 (9-10) ◽  
pp. 2055-2066
Author(s):  
Teruyuki Maruoka ◽  
Yoshiro Nishio ◽  
Tetsu Kogiso ◽  
Katsuhiko Suzuki ◽  
Takahito Osawa ◽  
...  
Keyword(s):  
Organic Matter ◽  
Iron Oxides ◽  
Sedimentary Rocks ◽  
Reductive Dissolution ◽  
X Ray ◽  
Asteroid Impact ◽  
Chalcophile Elements ◽  
The Difference ◽  
Impact Heating ◽  
Fe Ions

Abstract Chalcophile elements are enriched in the Cretaceous–Paleogene (KPg) boundary clays from Stevns Klint, Denmark. As the concentrations of Cu, Ag, and Pb among several chalcophile elements such as Cu, Zn, Ga, As, Ag, and Pb are correlated with those of Ir, we suggest that these elements were supplied to the oceans by processes related to the end-Cretaceous asteroid impact. Synchrotron X-ray fluorescence images revealed that Cu and Ag exist as trace elements in pyrite grains or as 1–10-µm-sized discrete phases specifically enriched in Cu or Ag. The difference in carrier phases might depend on the materials that transported these elements to the seafloor. Based on their affinities with Cu, Ag, and Ir, iron oxides/hydroxides and organic matter were identified as the potential carrier phases that supplied these elements to the seafloor. Chalcophile elements adsorbed on iron oxides/hydroxides might have been released during reductive dissolution of iron oxides/hydroxides and incorporated into the pyrite produced simultaneously with the reductive dissolution of iron oxides/hydroxides. Both iron oxides/hydroxides and chalcophile elements were possibly released from the KPg target rocks (i.e., sedimentary rocks and/or basement crystalline rocks) by impact heating. Elements with a high affinity to organic matter would have been released upon its degradation and then converted into discrete minerals because of the deficiency in Fe ions. As such discrete minerals include the elements that form acid soluble sulfides such as Cu, Ag, and Pb, enrichment of these elements might have been induced by the intense acid rain just after the end-Cretaceous asteroid impact.

scholarly journals Made-to-order porous electrodes for supercapacitors: MOFs embedded with redox-active centers as a case study

2020 ◽  
Vol 56 (12) ◽  
pp. 1883-1886 ◽  
Author(s):  
Arijit Mallick ◽  
Hanfeng Liang ◽  
Osama Shekhah ◽  
Jiangtao Jia ◽  
Georges Mouchaham ◽  
...  
Keyword(s):  
Porous Electrodes ◽  
Active Centers ◽  
Redox Active ◽  
Electrodes For Supercapacitors ◽  
The Way

These predesigned Zr-based MOFs could pave the way for many applications related to supercapacitors.

Application of target detection algorithms to identification of iron oxides using ASTER images: a case study in the North of Semnan province, Iran

2014 ◽  
Vol 8 (9) ◽  
pp. 7321-7331 ◽  
Author(s):  
Majid Rahimzadegan ◽  
Behnam Sadeghi ◽  
Manuchehr Masoumi ◽  
Siamak Taghizadeh Ghalehjoghi
Keyword(s):  
Iron Oxides ◽  
Target Detection ◽  
Detection Algorithms ◽  
The North ◽  
Semnan Province

scholarly journals Volcaniclastic habitats for early life on Earth and Mars: A case study from ∼3.5Ga-old rocks from the Pilbara, Australia

2011 ◽  
Vol 59 (10) ◽  
pp. 1093-1106 ◽  
Author(s):  
Frances Westall ◽  
Frédéric Foucher ◽  
Barbara Cavalazzi ◽  
Sjoukje T. de Vries ◽  
Wouter Nijman ◽  
...  
Keyword(s):  
Early Life ◽  
Life On Earth

The reductive dissolution of iron oxides by ascorbate

1990 ◽  
Vol 138 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Maria Dos Santos Afonso ◽  
Pedro J Morando ◽  
Miguel A Blesa ◽  
Steven Banwart ◽  
Werner Stumm
Keyword(s):  
Iron Oxides ◽  
Reductive Dissolution

scholarly journals Assessing the viability of biochemical networks across planets

2019 ◽  
Author(s):  
Harrison B. Smith ◽  
Alexa Drew ◽  
Sara I. Walker
Keyword(s):  
Quantitative Assessment ◽  
Chemical Compounds ◽  
Biochemical Networks ◽  
Geochemical Process ◽  
Computational Tools ◽  
Planetary Protection ◽  
Methodological Foundation ◽  
The Origin Of Life ◽  
Life On Earth

AbstractThe concept of the origin of life implies that initially, life emerged from a non-living medium. If this medium was Earth’s geochemistry, then that would make life, by definition, a geochemical process. The extent to which life on Earth today could subsist outside of the geochemistry from which it is embedded is poorly quantified. By leveraging large biochemical datasets in conjunction with planetary observations and computational tools, this research provides a methodological foundation for the quantitative assessment of our biology’s viability in the context of other geospheres. Investigating a case study of alkaline prokaryotes in the context of Enceladus, we find that the chemical compounds observed on Enceladus thus far would be insufficient to allow even these extremophiles to produce the compounds necessary to sustain a viable metabolism. The environmental precursors required by these organisms provides a map for the compounds which should be prioritized for detection in future planetary exploration missions. The results of this framework have further consequences in the context of planetary protection, and hint that forward contamination may prove infeasible without meticulous intent.

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