Mycelium

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Angel Manteca - One of the best experts on this subject based on the ideXlab platform.

  • quantitative proteomics analysis of streptomyces coelicolor development demonstrates that onset of secondary metabolism coincides with hypha differentiation
    Molecular & Cellular Proteomics, 2010
    Co-Authors: Angel Manteca, Jesús Sánchez, Hye Ryung Jung, Veit Schwammle, Ole Norregaard Jensen
    Abstract:

    Streptomyces species produce many clinically important secondary metabolites, including antibiotics and antitumorals. They have a complex developmental cycle, including programmed cell death phenomena, that makes this bacterium a multicellular prokaryotic model. There are two differentiated mycelial stages: an early compartmentalized vegetative Mycelium (first Mycelium) and a multinucleated reproductive Mycelium (second Mycelium) arising after programmed cell death processes. In the present study, we made a detailed proteomics analysis of the distinct developmental stages of solid confluent Streptomyces coelicolor cultures using iTRAQ (isobaric tags for relative and absolute quantitation) labeling and LC-MS/MS. A new experimental approach was developed to obtain homogeneous samples at each developmental stage (temporal protein analysis) and also to obtain membrane and cytosolic protein fractions (spatial protein analysis). A total of 345 proteins were quantified in two biological replicates. Comparative bioinformatics analyses revealed the switch from primary to secondary metabolism between the initial compartmentalized Mycelium and the multinucleated hyphae.

  • Mycelium differentiation and antibiotic production in submerged cultures of streptomyces coelicolor
    Applied and Environmental Microbiology, 2008
    Co-Authors: Angel Manteca, Ruben Alvarez, Nuria Salazar, Paula Yague, Jesús Sánchez
    Abstract:

    Despite the fact that most industrial processes for secondary metabolite production are performed with submerged cultures, a reliable developmental model for Streptomyces under these culture conditions is lacking. With the exception of a few species which sporulate under these conditions, it is assumed that no morphological differentiation processes take place. In this work, we describe new developmental features of Streptomyces coelicolor A3(2) grown in liquid cultures and integrate them into a developmental model analogous to the one previously described for surface cultures. Spores germinate as a compartmentalized Mycelium (first Mycelium). These young compartmentalized hyphae start to form pellets which grow in a radial pattern. Death processes take place in the center of the pellets, followed by growth arrest. A new multinucleated Mycelium with sporadic septa (second Mycelium) develops inside the pellets and along the periphery, giving rise to a second growth phase. Undecylprodigiosin and actinorhodin antibiotics are produced by this second Mycelium but not by the first one. Cell density dictates how the culture will behave in terms of differentiation processes and antibiotic production. When diluted inocula are used, the growth arrest phase, emergence of a second Mycelium, and antibiotic production are delayed. Moreover, pellets are less abundant and have larger diameters than in dense cultures. This work is the first to report on the relationship between differentiation processes and secondary metabolite production in submerged Streptomyces cultures.

  • A death round affecting a young compartmentalized Mycelium precedes aerial Mycelium dismantling in confluent surface cultures of Streptomyces antibioticus.
    Microbiology, 2005
    Co-Authors: Angel Manteca, Marisol Fernández, Jesús Sánchez
    Abstract:

    Development-associated cell-death processes were investigated in detail during the growth and differentiation of Streptomyces antibioticus ATCC 11891 on confluent surface cultures, by using fluorescent viability probes, membrane and activity fluorescence indicators, and electron microscopy analysis. A previously unsuspected complexity was revealed, namely the presence of a very young compartmentalized Mycelium that dies following an orderly pattern, leaving alternating live and dead segments in the same hypha. This death round is followed by the growth of a second Mycelium which develops rapidly from the live segments of the first Mycelium and dies massively in a second death round, which extends over the phases of aerial Mycelium formation and sporulation.

Bengt Soderstrom - One of the best experts on this subject based on the ideXlab platform.

  • spatial patterns of gene expression in the extramatrical Mycelium and mycorrhizal root tips formed by the ectomycorrhizal fungus paxillus involutus in association with birch betula pendula seedlings in soil microcosms
    New Phytologist, 2005
    Co-Authors: Derek P Wright, Bengt Soderstrom, Tomas Johansson, Antoine Le Quere, Anders Tunlid
    Abstract:

    (.)Functional compartmentation of the extramatrical Mycelium of ectomycorrhizal (ECM) fungi is considered important for the operation of ECM associations, although the molecular basis is poorly characterized. (.)Global gene expression profiles of Mycelium colonizing an ammonium sulphate ((NH4)(2)SO4) nutrient patch, rhizomorphs and ECM root tips of the Betula pendula-Paxillus involutus association were compared by cDNA microarray analysis. (.)The expression profiles of rhizomorphs and nutrient patch Mycelium were similar to each other but distinctly different from that of mycorrhizal tips. Statistical analyses revealed 337 of 1075 fungal genes differentially regulated among these three tissues. Clusters of genes exhibiting distinct expression patterns within specific tissues were identified. Genes implicated in the glutamine synthetase/glutamate synthase (GS/GOGAT) and urea cycles, and the provision of carbon skeletons for ammonium assimilation via beta-oxidation and the glyoxylate cycle, were highly expressed in rhizomorph and nutrient patch Mycelium. Genes implicated in vesicular transport, cytoskeleton organization and morphogenesis and protein degradation were also differentially expressed. (.)Differential expression of genes among the extramatrical Mycelium and mycorrhizal tips indicates functional specialization of tissues forming ECM associations. (c) New Phytologist ( 2005). (Less)

  • arbuscular mycorrhizal fungi respond to the substrate ph of their extraradical Mycelium by altered growth and root colonization
    New Phytologist, 2002
    Co-Authors: Ingrid M Van Aarle, Pål Axel Olsson, Bengt Soderstrom
    Abstract:

    To test the response of arbuscular mycorrhizal (AM) fungi to a difference in soil pH, the extraradical Mycelium of Scutellospora calospora or Glomus intraradices, in association with Plantago lanceolata, was exposed to two different pH treatments, while the root substrate pH was left unchanged. Seedlings of P. lanceolata, colonized by one or other of the fungal symbionts, and nonmycorrhizal controls, were grown in mesh bags placed in pots containing pH-buffered sand (pH around 5 or 6). The systems were harvested at approximately 2-wk intervals between 20 and 80 d. Both fungi formed more extraradical Mycelium at the higher pH. Glomus intraradices formed almost no detectable extraradical Mycelium at lower pH. The extraradical Mycelium of S. calospora had higher acid phosphatase activity than that of G. intraradices. Total AM root colonization decreased for both fungi at the higher pH, and high pH also reduced arbuscule and vesicle formation in G. intraradices. In conclusion, soil pH influences AM root colonization as well as the growth and phosphatase activities of extraradical Mycelium, although the two fungi responded differently.

  • growth of arbuscular mycorrhizal Mycelium in calcareous dune sand and its interaction with other soil microorganisms as estimated by measurement of specific fatty acids
    Plant and Soil, 1998
    Co-Authors: Pål Axel Olsson, David Read, R Francis, Bengt Soderstrom
    Abstract:

    Fatty acid analysis was used for determining the extent of the development of the external Mycelium of AM fungi (mixed inoculum from a sand dune) growing from roots of Festuca rubra and Plantago lanceolata in calcareous dune sand. The plants were raised in chambers specially designed to permit the growth of AM Mycelium in root-free compartments. In two separate experiments, growth of external Mycelium in the root-free compartments was detected and the amount of Mycelium was estimated using the indicator of AM fungal biomass, phospholipid fatty acid (PLFA) 16:1 omega 5. The results showed that the PLFA 16:1 omega 5 was suitable for estimating the Mycelium emerging from the mixed inoculum obtained from the field roots of F: rubra and P lanceolata. The PLFA 16:1 omega 5 showed external Mycelium to become established in the root-free compartments within a period of 3 weeks and the amount of Mycelium to continue to increase at 6 and 9 weeks. Increases in neutral lipid fatty acid (NLFA) 16:1 omega 5 (indicator of storage lipids) over time were inconsistent between the two experiments, but appeared to follow patterns of sporulation in each experiment. In both experiments, the root-free compartment was colonised by saprophytic fungi to a greater extent in the case of non-mycorrhizal than of AM treatment, as indicated by an increase in PLFA 18:2 omega 6,9 (indicator of saprophytic fungi). The absence of an increase in the case of AM treatment indicates that AM fungal Mycelium can negatively affect the growth of saprophytic fungi in this soil type. This result was, however, only weakly supported by measurements of ergosterol content. The analysis of bacteria specific PLFAs showed that bacterial biomass was not affected by the AM Mycelium.

  • growth and assimilation of nh4 and no3 by paxillus involutus in association with betula pendula and picea abies as affected by substrate ph
    New Phytologist, 1994
    Co-Authors: Hans Ek, Solbritt Andersson, Kristina Arnebrant, Bengt Soderstrom
    Abstract:

    The influence of pH on the growth and assimilation of N-15-labelled ammonium and nitrate was studied in intact ectomycorrhizal systems consisting of Betula pendula Roth and Picea abies (L.) Karst. colonized with a common Mycelium of Paxillus involutus (Batsch) Fr. The plants were grown together in Plexiglass observation chambers containing non-sterile peat with three different pH values, 4.0, 5.1 and 6.1. The mycorrhizal Mycelium was allowed to grow over a barrier into an area of peat from which plant roots were excluded. Labelled NH4NO3 was supplied, either as (NH4NO3)-N-15 or as (NH4NO3)-N-15, exclusively to the fungal Mycelium. Shoots and roots were analyzed for N-15 in total nitrogen while the Mycelium was analyzed for N-15 in NH4+, NO3- and free amino acids. The N-15 labelling pattern indicated that ammonium was immediately assimilated into amino acids, primarily glutamine, by the fungal Mycelium at the uptake site. The amino acids were then translocated to the mycorrhizal roots. In contrast, nitrate-N was not assimilated in the Mycelium but rather transferred to the mycorrhizal roots as nitrate. Mycelial uptake and transfer of N to the spruce and birch seedlings were significantly higher for NH4-N than for NO3-N. No firm conclusions about pH effects on the preferential uptake of ammonium and nitrate could be drawn. However, pH had a pronounced effect on the mycelial growth of P. involutus which was hampered severely at pH 6.1 and to a lesser extent at pH 5.1.

Jesús Sánchez - One of the best experts on this subject based on the ideXlab platform.

  • quantitative proteomics analysis of streptomyces coelicolor development demonstrates that onset of secondary metabolism coincides with hypha differentiation
    Molecular & Cellular Proteomics, 2010
    Co-Authors: Angel Manteca, Jesús Sánchez, Hye Ryung Jung, Veit Schwammle, Ole Norregaard Jensen
    Abstract:

    Streptomyces species produce many clinically important secondary metabolites, including antibiotics and antitumorals. They have a complex developmental cycle, including programmed cell death phenomena, that makes this bacterium a multicellular prokaryotic model. There are two differentiated mycelial stages: an early compartmentalized vegetative Mycelium (first Mycelium) and a multinucleated reproductive Mycelium (second Mycelium) arising after programmed cell death processes. In the present study, we made a detailed proteomics analysis of the distinct developmental stages of solid confluent Streptomyces coelicolor cultures using iTRAQ (isobaric tags for relative and absolute quantitation) labeling and LC-MS/MS. A new experimental approach was developed to obtain homogeneous samples at each developmental stage (temporal protein analysis) and also to obtain membrane and cytosolic protein fractions (spatial protein analysis). A total of 345 proteins were quantified in two biological replicates. Comparative bioinformatics analyses revealed the switch from primary to secondary metabolism between the initial compartmentalized Mycelium and the multinucleated hyphae.

  • Mycelium differentiation and antibiotic production in submerged cultures of streptomyces coelicolor
    Applied and Environmental Microbiology, 2008
    Co-Authors: Angel Manteca, Ruben Alvarez, Nuria Salazar, Paula Yague, Jesús Sánchez
    Abstract:

    Despite the fact that most industrial processes for secondary metabolite production are performed with submerged cultures, a reliable developmental model for Streptomyces under these culture conditions is lacking. With the exception of a few species which sporulate under these conditions, it is assumed that no morphological differentiation processes take place. In this work, we describe new developmental features of Streptomyces coelicolor A3(2) grown in liquid cultures and integrate them into a developmental model analogous to the one previously described for surface cultures. Spores germinate as a compartmentalized Mycelium (first Mycelium). These young compartmentalized hyphae start to form pellets which grow in a radial pattern. Death processes take place in the center of the pellets, followed by growth arrest. A new multinucleated Mycelium with sporadic septa (second Mycelium) develops inside the pellets and along the periphery, giving rise to a second growth phase. Undecylprodigiosin and actinorhodin antibiotics are produced by this second Mycelium but not by the first one. Cell density dictates how the culture will behave in terms of differentiation processes and antibiotic production. When diluted inocula are used, the growth arrest phase, emergence of a second Mycelium, and antibiotic production are delayed. Moreover, pellets are less abundant and have larger diameters than in dense cultures. This work is the first to report on the relationship between differentiation processes and secondary metabolite production in submerged Streptomyces cultures.

  • A death round affecting a young compartmentalized Mycelium precedes aerial Mycelium dismantling in confluent surface cultures of Streptomyces antibioticus.
    Microbiology, 2005
    Co-Authors: Angel Manteca, Marisol Fernández, Jesús Sánchez
    Abstract:

    Development-associated cell-death processes were investigated in detail during the growth and differentiation of Streptomyces antibioticus ATCC 11891 on confluent surface cultures, by using fluorescent viability probes, membrane and activity fluorescence indicators, and electron microscopy analysis. A previously unsuspected complexity was revealed, namely the presence of a very young compartmentalized Mycelium that dies following an orderly pattern, leaving alternating live and dead segments in the same hypha. This death round is followed by the growth of a second Mycelium which develops rapidly from the live segments of the first Mycelium and dies massively in a second death round, which extends over the phases of aerial Mycelium formation and sporulation.

Monika Welc - One of the best experts on this subject based on the ideXlab platform.

  • suppression of other soil microorganisms by Mycelium of arbuscular mycorrhizal fungi in root free soil
    Soil Biology & Biochemistry, 2010
    Co-Authors: Monika Welc, Sabine Ravnskov, Barbara Kieliszewskarokicka, John Larsen
    Abstract:

    The influence of Mycelium of two arbuscular mycorrhizal (AM) fungi, Glomus intraradices and Glomus mosseae, on other soil microorganisms, was examined in root-free soil with and without organic substrate amendment in terms of cellulose. The AM fungi were grown in symbiosis with cucumber in a compartmented growth system, which allowed AM fungal external Mycelium to grow into root-free compartments. The fungicide Benomyl was applied to the root-free compartments to create an alternative non-mycorrhizal control treatment. Whole cell biomarker fatty acids were employed to quantify different groups of soil microorganisms including the two AM fungi. Abundance of most microbial groups were reduced by external Mycelium of both AM fungi, though differential effects on the microbial community composition were observed between the two AM fungi as revealed from principal component analysis. Inhibition of other soil microorganisms was more pronounced in root-free soil with Mycelium of G. mosseae than with Mycelium of G. intraradices. In general, cellulose increased the amount of biomarker fatty acids of most groups of soil microorganisms, but cellulose did not affect the influence of AM fungi on other soil microorganisms. Benomyl suppressed growth of the external Mycelium of the two AM fungi and had limited non-target effects on other microbial groups. In conclusion, our results show differential effects of external Mycelium of AM fungi on other soil microbial communities, though both AM fungi included in the study overall inhibited most microbial groups as examined using whole cell biomarker fatty acids.

John Larsen - One of the best experts on this subject based on the ideXlab platform.

  • suppression of other soil microorganisms by Mycelium of arbuscular mycorrhizal fungi in root free soil
    Soil Biology & Biochemistry, 2010
    Co-Authors: Monika Welc, Sabine Ravnskov, Barbara Kieliszewskarokicka, John Larsen
    Abstract:

    The influence of Mycelium of two arbuscular mycorrhizal (AM) fungi, Glomus intraradices and Glomus mosseae, on other soil microorganisms, was examined in root-free soil with and without organic substrate amendment in terms of cellulose. The AM fungi were grown in symbiosis with cucumber in a compartmented growth system, which allowed AM fungal external Mycelium to grow into root-free compartments. The fungicide Benomyl was applied to the root-free compartments to create an alternative non-mycorrhizal control treatment. Whole cell biomarker fatty acids were employed to quantify different groups of soil microorganisms including the two AM fungi. Abundance of most microbial groups were reduced by external Mycelium of both AM fungi, though differential effects on the microbial community composition were observed between the two AM fungi as revealed from principal component analysis. Inhibition of other soil microorganisms was more pronounced in root-free soil with Mycelium of G. mosseae than with Mycelium of G. intraradices. In general, cellulose increased the amount of biomarker fatty acids of most groups of soil microorganisms, but cellulose did not affect the influence of AM fungi on other soil microorganisms. Benomyl suppressed growth of the external Mycelium of the two AM fungi and had limited non-target effects on other microbial groups. In conclusion, our results show differential effects of external Mycelium of AM fungi on other soil microbial communities, though both AM fungi included in the study overall inhibited most microbial groups as examined using whole cell biomarker fatty acids.