Glucosylglycerate is an osmotic solute and an extracellular metabolite produced byStreptomyces caelestis

2007 ◽  
Vol 52 (5) ◽  
pp. 451-456 ◽  
Author(s):  
S. Pospíšil ◽  
P. Halada ◽  
M. Petříček ◽  
P. Sedmera
Keyword(s):  
Extracellular Metabolite ◽  
Osmotic Solute

Periphytic microbial response to environmental phosphate bioavailability – relevance to P management in paddy fields

2021 ◽  
Author(s):  
Jianchao Zhang ◽  
Jing Su ◽  
Chao Ma ◽  
Xiangyu Hu ◽  
Henry H Teng
Keyword(s):  
Management Strategies ◽  
Phosphorus Uptake ◽  
Paddy Fields ◽  
P Availability ◽  
Biochemical Processes ◽  
Extracellular Metabolite ◽  
Microbial Response ◽  
P Utilization ◽  
Water Ecosystems ◽  
And Storage

Periphyton occurs widely in shallow-water ecosystems such as paddy fields and plays critical parts in regulating local phosphorus cycling. As such, understanding the mechanisms of the biofilm’s response to environmental P variability may lead to better perceptions of P utilization and retention in rice farms. Present study aims at exploring the biological and biochemical processes underlying periphyton’s P buffering capability through examining changes in community structure, phosphorus uptake and storage, and molecular makeup of exometabolome at different levels of P availability. Under stressed (both excessive and scarce) phosphorus conditions, we found increased populations of the bacterial genus capable of transforming orthophosphate to polyphosphate, as well as mixotrophic algae who can survive through phagotrophy. These results were corroborated by observed polyphosphate buildup under low and high P treatment. Exometabolomic analyses further revealed that periphytic organisms may substitute S-containing lipids for phospholipids, use siderophores to dissolve iron (hydr)oxides to scavenge adsorbed P, and synthesize auxins to resist phosphorus starvation. These findings not only shed light on the mechanistic insights responsible for driving the periphytic P buffer but attest to the ecological roles of periphyton in aiding plants such as rice to overcome P limitations in natural environment. Importance The ability of periphyton to buffer environmental P in shallow aquatic ecosystems may be a natural lesson on P utilization and retention in paddy fields. This work revealed the routes and tools through which periphytic organisms adapt to and regulate ambient P fluctuation. The mechanistic understanding further implicates that the biofilm may serve rice plants to alleviate P stress. Additional results from extracellular metabolite analyses suggest the dissolved periphytic exometabolome can be a valuable nutrient source for soil microbes and plants to reduce biosynthetic costs. These discoveries have the potential to improve our understanding of biogeochemical cycling of phosphorus in general and to refine P management strategies for rice farm in particular.

scholarly journals The enhancement of drought tolerance for pigeon pea inoculated by arbuscular mycorrhizae fungi

2011 ◽  
Vol 57 (No. 12) ◽  
pp. 541-546 ◽  
Author(s):  
G. Qiao ◽  
X.P. Wen ◽  
L.F. Yu ◽  
X.B. Ji
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Arbuscular Mycorrhizae ◽  
Soluble Sugar ◽  
Lipid Peroxides ◽  
Am Fungi ◽  
Pigeon Pea ◽  
Positive Effects ◽  
Am Symbiosis ◽  
Osmotic Solute

  Pigeon pea (Cajanus cajan) has been rapidly grown in the drought-striken Karst regions of southwest China. Present research aimed to investigate the effects of arbuscular mycorrhizae (AM) on the drought tolerance of pigeon pea, as well as to elucidate the physiological responses of AM-colonized seedlings to the water deficit. As subjected to drought stress, AM symbiosis (AMD) highly led to the positive effects on root system, plant height and stem diameter. AMD demonstrated a remarkably higher chlorophyll content, photosynthetic rate and stomatal conductance. The soluble sugar in AMD was significantly higher than that of the non-AM seedlings (NAMD), indicating the enhanced tolerance at least partially correlated with osmotic solute. Conversely, the proline (Pro) of AMD was lower, revealing the excessive Pro was not imperative for drought tolerance. After 30 days drought stress, AMD gave around a third less lipid peroxides than that of NAMD. Rather, the root activities of AMD were significantly higher than that of the latter after 10 days drought stress. Thereby, AM fungi might substantially elevate the tolerance to drought of pigeon pea, and the cumulative effects contributed to the enhanced tolerance. To date, this has been the first report concerning the enhancement of drought tolerance via AM colonization in this legume species.  

N-Acetylglucosamine: A New Osmotic Solute in Peritoneal Dialysis Solutions

1997 ◽  
Vol 17 (2_suppl) ◽  
pp. 80-83 ◽  
Author(s):  
Andrzej Breborowicz ◽  
Katarzyna Wieczorowska-Tobis ◽  
Malgorzata Kuzlan ◽  
Justyna Kupsz ◽  
Katarzyna Korybalska ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Dialysis Solutions ◽  
Osmotic Solute ◽  
Peritoneal Dialysis Solutions

Sorption properties of cambuci (Campomanesia phaea O. Berg) untreated and pre-treated with sorbitol as osmotic solute

LWT ◽  
2020 ◽  
pp. 110569
Author(s):  
Mariana Schincariol Paes ◽  
Pedro de Alcântara Pessoa Filho ◽  
Carmen Cecília Tadini
Keyword(s):  
Sorption Properties ◽  
Osmotic Solute

The Use of Alternative Peritoneal Dialysis Solutions in Pediatric Patients

1993 ◽  
Vol 13 (2_suppl) ◽  
pp. 95-97 ◽  
Author(s):  
John Williamson Balfe ◽  
Izhar Qamar
Keyword(s):  
Amino Acids ◽  
Peritoneal Dialysis ◽  
Pediatric Patients ◽  
Dialysis Solution ◽  
Peritoneal Dialysis Solution ◽  
Calcium And Magnesium ◽  
Dialysis Solutions ◽  
Osmotic Solute ◽  
Peritoneal Dialysis Solutions

Changes in the formulation of peritoneal dialysis solutions will continue. For the present, dextrose dialysis will remain the osmotic solute of choice. How amino acids and glucose polymers as solute replace ments for glucose fit into the dialysis prescription remains to be seen. The lower concentration of calcium and magnesium appears to be gaining acceptance in many centers. It is feasible that in the next few years the challenge of adding bicarbonate to the peritoneal dialysis solution will be circumvented, because there appears to be a real clinical need for such an improvement. Pediatric modifications will be necessary, appreciating that such changes will have an economic penalty, and thus must have proven value.

scholarly journals Serratia marcescens shapes cutaneous bacterial communities and influences survival of an amphibian host

2019 ◽  
Vol 286 (1914) ◽  
pp. 20191833 ◽  
Author(s):  
Joseph D. Madison ◽  
Scot P. Ouellette ◽  
Emme L. Schmidt ◽  
Jacob L. Kerby
Keyword(s):  
Microbial Community ◽  
Serratia Marcescens ◽  
Batrachochytrium Dendrobatidis ◽  
Genetically Modified ◽  
Alpha Diversity ◽  
Emerging Diseases ◽  
Differential Survival ◽  
Extracellular Metabolite

Ongoing investigations into the interactions between microbial communities and their associated hosts are changing how emerging diseases are perceived and ameliorated. Of the numerous host–microbiome–disease systems of study, the emergence of chytridiomycosis (caused by Batrachochytrium dendrobatidis , hereafter Bd ) has been implicated in ongoing declines and extinction events of amphibians worldwide. Interestingly, there has been differential survival among amphibians in resisting Bd infection and subsequent disease. One factor thought to contribute to this resistance is the host-associated cutaneous microbiota. This has raised the possibility of using genetically modified probiotics to restructure the host-associated microbiota for desired anti-fungal outcomes. Here, we use a previously described strain of Serratia marcescens ( Sm ) for the manipulation of amphibian cutaneous microbiota. Sm was genetically altered to have a dysfunctional pathway for the production of the extracellular metabolite prodigiosin. This genetically altered strain (Δ pig ) and the functional prodigiosin producing strain (wild-type, WT) were compared for their microbial community and anti- Bd effects both in vitro and in vivo . In vitro , Bd growth was significantly repressed in the presence of prodigiosin. In vivo , the inoculation of both Sm strains was shown to significantly influence amphibian microbiota diversity with the Δ pig-Sm treatment showing increasing alpha diversity, and the WT- Sm having no temporal effect on diversity. Differences were also seen in host mortality with Δ pig-Sm treatments exhibiting significantly decreased survival probability when compared with WT- Sm in the presence of Bd . These results are an important proof-of-concept for linking the use of genetically modified probiotic bacteria to host microbial community structure and disease outcomes, which in the future may provide a way to ameliorate disease and address critical frontiers in disease and microbial ecology.

scholarly journals Evaluation of Bacterial Antagonists for Biological Control of Broccoli Head Rot Caused by Pseudomonas fluorescens

2006 ◽  
Vol 96 (4) ◽  
pp. 408-416 ◽  
Author(s):  
Xiaohui Cui ◽  
Rob Harling
Keyword(s):  
Biological Control ◽  
Quorum Sensing ◽  
Pseudomonas Fluorescens ◽  
Virulence Gene ◽  
Pathogenicity Test ◽  
Bacillus Sp ◽  
Inhibitory Effects ◽  
Extracellular Metabolite ◽  
Head Rot ◽  
Tn5 Mutant

Pectolytic strains of Pseudomonas fluorescens are opportunistic pathogens of broccoli, causing head rot in temperate regions of the world. In this study, we investigated the potential of two bacterial isolates, P. fluorescens m6418 and Bacillus sp. A24, for biological control of broccoli head rot caused by P. fluorescens 5064, isolated from diseased broccoli in Scotland, UK. P. fluorescens m6418, a Tn5 mutant of wild-type 5064, is nonpathogenic and overproduces an extracellular metabolite with strong antimicrobial activity. In this study, we identified the anti-microbial metabolite produced by strain m6418 as pyrrolnitrin. P. fluorescens m6418 had significant inhibitory effects against strain 5064 both in culture and on broccoli leaves. In an excised broccoli head pathogenicity test, strain m6418, when coinoculated with P. fluorescens 5064, reduced disease by 41%. Bacillus sp. A24 produces an enzyme that can degrade N-acyl homoserine lactones, signaling molecules employed by bacteria for quorum sensing. Bacillus sp. A24 was capable of out-competing P. fluorescens 5064 when grown together in culture, and could degrade the quorum sensing signal of P. fluorescens 5064 (and thereby attenuate its virulence gene production). However, Bacillus sp. A24 had only a limited biocontrol effect on P. fluorescens 5064 in the excised broccoli head assay.

Osmotic solute responses of mycorrhizal citrus (Poncirus trifoliata) seedlings to drought stress

2007 ◽  
Vol 29 (6) ◽  
pp. 543-549 ◽  
Author(s):  
Qiang-Sheng Wu ◽  
Ren-Xue Xia ◽  
Ying-Ning Zou ◽  
Gui-Yuan Wang
Keyword(s):  
Drought Stress ◽  
Poncirus Trifoliata ◽  
Osmotic Solute

scholarly journals Theoretical Analysis of Net Tracer Flux Due to Volume Circulation in a Membrane with Pores of Different Sizes

1971 ◽  
Vol 57 (2) ◽  
pp. 113-124 ◽  
Author(s):  
Clifford S. Patlak ◽  
Stanley I. Rapoport
Keyword(s):  
Theoretical Analysis ◽  
Alternative Model ◽  
Interaction Model ◽  
External Pressure ◽  
Volume Flow ◽  
Artificial Membrane ◽  
Solute Interaction ◽  
Osmotic Solutes ◽  
Net Flux ◽  
Osmotic Solute

When osmotic pressure across an artificial membrane, produced by a permeable electrically neutral solute on one side of it, is balanced by an external pressure difference so that there is no net volume flow across the membrane, it has been found that there will be a net flux of a second electrically neutral tracer solute, present at equal concentrations on either side of the membrane, in the direction that the "osmotic" solute diffuses. This has been ascribed to solute-solute interaction or drag between the tracer and the osmotic solutes. An alternative model, presented here, considers the membrane to have pores of different sizes. Under general assumptions, this "heteroporous" model will account for both the direction of net tracer flux and the observed linear dependence of unidirectional tracer fluxes on the concentration of the osmotic solute. The expressions for the fluxes of solutes and solvent are mathematically identical under the two models. An inequality is derived which must be valid if the solute interaction model and/or the heteroporous model can account for the data. If the inequality does not hold, then the heteroporous model alone cannot explain the data. It was found that the inequality holds for most published observations except when dextran is the osmotic solute.

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