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Active Growth (active + growth)
Selected AbstractsUse of monoclonal antibodies to quantify the dynamics of ,-galactosidase and endo-1,4-,-glucanase production by Trichoderma hamatum during saprotrophic growth and sporulation in peatENVIRONMENTAL MICROBIOLOGY, Issue 5 2005Christopher R. Thornton Summary Trichoderma species are ubiquitous soil and peat-borne saprotrophs that have received enormous scientific interest as biocontrol agents of plant diseases caused by destructive root pathogens. Mechanisms of biocontrol such as antibiosis and hyperparasitism are well documented and the biochemistry and molecular genetics of these processes defined. An aspect of biocontrol that has received little attention is the ability of Trichoderma species to compete for nutrients in their natural environments. Trichoderma species are efficient producers of polysaccharide-degrading enzymes that enable them to colonize organic matter thereby preventing the saprotrophic spread of plant pathogens. This study details the use of monoclonal antibodies (mAbs) to quantify the production of two enzymes implicated in the saprotrophic growth of Trichoderma species in peat. Using mAbs specific to the hemicellulase enzyme ,-galactosidase (AGL) and the cellulase enzyme endo-1,4-,-glucanase (EG), the relationship between the saprotrophic growth dynamics of a biocontrol strain of Trichoderma hamatum and the concomitant production of these enzymes in peat-based microcosms was studied. Enzyme activity assays and enzyme protein concentrations derived by enzyme-linked immunosorbent assay (ELISA) established the precision and sensitivity of mAb-based assays in quantifying enzyme production during active growth of the fungus. Trends in enzyme activities and protein concentrations were similar for both enzymes, during a 21-day sampling period in which active growth and sporulation of the fungus in peat was quantified using an independent mAb-based assay. There was a sharp increase in active biomass of T. hamatum 3 days after inoculation of microcosms with phialoconidia. After 3 days there was a rapid decline in active biomass which coincided with sporulation of the fungus. A similar trend was witnessed with EG activities and concentrations. This showed that EG production related directly to active growth of the fungus. The trend was not found, however, with AGL. There was a rapid increase in enzyme activities and protein concentrations on day 3, after which they remained static. The reason for the maintenance of elevated AGL probably resulted from secretion of the enzyme from conidia and chlamydospores. ELISA, immunofluoresence and immunogold electron microscopy studies of these cells showed that the enzyme is localized within the cytoplasm and is secreted extracellularly into the surrounding environment. It is postulated that release of oligosaccharides from polymeric hemicellulose by the constitutive spore-bound enzyme leads to AGL induction and could act as an environmental cue for spore germination. [source] Variable alluvial sandstone architecture within the Lower Old Red Sandstone, southwest WalesGEOLOGICAL JOURNAL, Issue 3-4 2004Brian P. J. Williams Abstract Sandstone bodies within the Lower Old Red Sandstone (ORS) in southern Pembrokeshire exhibit variability in architecture, sediment grade and composition both spatially and temporally. Four architectural styles are observed, namely decimetre- to metre-thick sheets, metre-thick multi-storey amalgamations, inclined-heterolithic units and ribbon geometries. Sandstone bodies in the Freshwater East Formation are sheet-like, heterolithic units several metres thick. An association with lingulids and wave ripples alludes to a marine influence, possibly estuarine tidal flats or storm washovers. Within the Moor Cliffs Formation, the most common sandstone bodies are centimetre- to metre-thick sheets with high width-to-depth ratios. Fine-grained sandstones represent sheet-flood deposition on unconfined, planar surfaces, whereas coarser-grained sandstones constitute distinctive amalgamations of discrete flood events, reflecting either a change in provenance or tectonic influence. Clear incision of coarse-grained, multi-storey units within the Inter-Tuff Moor Cliffs Formation reflects a change in relative sea-level, possibly tectonically induced. The base of the Conigar Pit Sandstone Member (CPSM) is marked by a distinctive, exotic-clast conglomerate defining the base to heterolithic, lateral-accretion bedsets and sandstone sheets. This association defines a significant influx of coarse-grained sediment post-Chapel Point Calcrete formation, an interval of presumed topographic stability across the Anglo-Welsh Basin. This influx must reflect rejuvenation of source regions, with changes in base-level reflecting either eustatic or tectonic influences. Commonly observed in the CPSM are fine-grained, inclined-heterolithic bedsets recording deposition by highly sinuous rivers with flashy discharge. Up-sequence within the CPSM are metre-thick, multi-storey amalgamations of predominatly trough cross-stratified medium- to coarse-grained sandstone. It is likely that these units are genetically related to contemporaneous decimetre-thick sandstone sheets, the latter being ,splay' events marginal to the main channel axis. The interbedding of multi-storey sandstones and fine-grained laterally accreted units reflects changes in provenance, slope and/or climate. Thickness variations within the Lower ORS detail significant thickening of all units northward into the Benton Fault. It seems likely that this thickening reflects variable accommodation space development associated with active growth along this and other WNW,ESE-trending faults, and migration of channel belts toward the footwall. Copyright © 2004 John Wiley & Sons, Ltd. [source] Stimulatory Effect of Procaine on the Growth of Several Microalgae and CyanobacteriaJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2000TAKAHIRO SUZUKI Procaine has been used to stimulate plant growth and it has been noted that it also promotes growth of microorganisms. The effect of procaine hydrochloride concentration on the growth rates of several species of microalgae and cyanobacteria was studied under both photoautotropic and heterotrophic growth conditions. Procaine hydrochloride was added to cultures at concentrations over the range 0.01,1000 mg L,1. A stimulating effect of procaine hydrochloride on photoautotrophic growth was observed for the cyanobacteria Anabaena cylindrica and Anabaena variabilis, and for the salt-tolerant green algae Dunaliella primolecta and Dunaliella parva. During active growth in batch culture an increase in growth rate (compared with control culture without procaine hydrochloride) of about 25% was observed at 0.1 mg L,1 of procaine hydrochloride for A. cylindrica. However, procaine hydrochloride was toxic at concentrations of > 10 mg L,1. Simultaneous administration of hydrolysis products of procaine, p -amino-benzoic acid and diethyl aminoethanol, in lieu of procaine hydrochloride, was as effective as procaine in stimulating growth of A. cylindrica. Heterotrophic growth of Chlorella ellipsoidea and Prototheca zopfii was not stimulated by procaine hydrochloride over the concentration range studied (0.1,10 mg L,1). The combined effects of procaine hydrochloride concentration and four other environmental factors (temperature, light intensity, CO2 concentration in the flushing gas and NaCl concentration) on growth rate of D. primolecta was modelled using both a neural network approach and a response surface method. These results indicate that procaine hydrochloride exerts different effects on the growth of microalgal and cyanobacterial cells as functions of dosage, species and culture conditions. [source] Exploring the species diversity of Trichoderma in Norwegian drinking water systems by DNA barcodingMOLECULAR ECOLOGY RESOURCES, Issue 6 2008GUNHILD HAGESKAL Abstract A total of 123 Trichoderma strains were isolated from Norwegian surface-sourced drinking water. The water samples included raw water, treated water, and water from private homes and hospital installations. Trichoderma species are difficult to differentiate morphologically, but recent molecular identification tools, including DNA barcoding, successfully distinguish between closely related species. The diversity of Trichoderma spp. was explored by DNA sequencing of internal transcribed spacer (ITS) and translation elongation factor 1 alpha (TEF-1,). Sequence identification was performed in the TrichOKEY version 2.0 barcode program and in the multilocus similarity search database TrichoBLAST, combined with traditional blast searches in the EMBL/GenBank. A total of 11 known Trichoderma/Hypocrea species were identified. In addition, one group of unidentified Trichoderma strains was found to represent a separate, strongly supported subclade within the Pachybasium,A'/Hamatum clade, based on their TEF-1, haplotypes. Trichoderma viride comprised 49% of the identified strains, and was represented by four and eight slightly different ITS and TEF-1, haplotypes, respectively. Approximately 22% of the surface-derived water samples were positive for T. viride, and the species was frequently isolated throughout the surface-sourced drinking water distribution system. The results indicate that a broad range of Trichoderma species are present in Norwegian surface-sourced drinking. Water treatment has minor effect in removing Trichoderma from raw water, and active growth in the water distribution system is likely to occur. [source] Variation in physiological health of diademed sifakas across intact and fragmented forest at Tsinjoarivo, eastern MadagascarAMERICAN JOURNAL OF PRIMATOLOGY, Issue 11 2010Mitchell T. Irwin Abstract As undisturbed habitat becomes increasingly rare, managers charged with ensuring the survival of endangered primate species must increasingly utilize disturbed and degraded habitats in species survival plans. Yet we have an imperfect understanding of the true long-term viability of primate populations in disturbed habitat, and census data can be misleading because density is not necessarily correlated with habitat quality and population viability in predictable ways. Here we present clinical laboratory data on hematology, serum biochemistry, fat-soluble vitamins, minerals, iron analytes, viral serology, and parasitology of diademed sifaka (Propithecus diadema), derived from the capture of 26 individuals spanning eight groups and two habitats (undisturbed vs. disturbed and fragmented) at Tsinjoarivo, Madagascar. Blood from fragment individuals had significantly lower values for several factors: white blood cell counts, bilirubin, total protein, albumin, calcium, sodium, chloride, manganese, zinc, iron and total iron-binding capacity. Several biochemical variables were higher in immature individuals, probably due to active growth. The large number of interhabitat differences suggests that habitat disturbance has an impact on physiological health within this population, perhaps reflecting dietary stress and/or immunosuppression. These results, combined with previous data showing altered diet, slower juvenile growth, and reduced activity in disturbed forest fragments, suggest that fragment sifakas may be less healthy than continuous forest groups. Finally, Tsinjoarivo sifakas have extremely low blood urea nitrogen (perhaps reflecting protein limitation) and selenium levels relative to other lemurs. Despite their survival and reproduction in the short term in fragments, these sifakas may represent a riskier conservation investment than conspecifics in undisturbed forest, and may be more susceptible to environmental stressors. However, more data on the fitness consequences of these biochemical differences are needed for a better interpretation of their impacts on long-term viability prospects. Am. J. Primatol. Am. J. Primatol. 72:1013,1025, 2010. © 2010 Wiley-Liss, Inc. [source] | ||||||||||