Pure culture growth of ectomycorrhizal fungi on inorganic nitrogen sources

Four ectomycorrhizal fungi were tested for their ability to grow (i.e., mycelial mat radial extension and fungal biomass) on nutrient media either supplemented with ammonium-nitrogen or nitrate-nitrogen or in the absence of an inorganic nitrogen source.Pisolithus tinctorius, Cenococcum geophilum andThelephora terrestris exhibited greater growth on ammonium-nitrogen.Suillus granulatus grew better on the nitrate-nitrogen nutrient medium. Regardless of inorganic nitrogen form preference (i.e., ammonium-nitrogen or nitrate-nitrogen), all 4 species showed some growth on each of the 3 nutrient media. Growth rate maxima varied by fungal species as well as by inorganic nitrogen source. Maximum growth rate forT. terrestris exceeded rates exhibited by the other 3 fungi by 2–5 times.     

Studies of the degraded carrageenan-induced colitis of rabbits. II. Changes in the epithelial glycoprotein O-acylated sialic acids associated with the induction and healing phases

Summary Rabbits fed freely with a 1% aqueous solution of degraded carrageenan developed a progressive colitis characterized after five days by severe inflammation and mucosal ulceration of the caecum. Histochemical and chemical studies indicated that there was a marked reduction in intracellular mucin and in the proportion of the epithelial glycoprotein sialic acids with substituents in the side chain and at position C₄. Changes in theO-acylated sialic acids occurred rapidly and, apparently, prior to either mucosal ulceration or a significant inflammatory response.Following the removal of carrageenan from the diet, there was evidence of progressive healing characterized by re-epitheliazation and a reduction in the inflammatory response until, at 12 days, the mucosa was comparatively normal. Healing was accompanied by an apparent increase in intracellular mucin and in the proportion of the epithelial glycoprotein sialic acids with substituents in the side chain and at position C₄. Animals sacrificed 20 days after withdrawal of the carrageenan showed a renewal of ulceration characterized by an active inflammatory process, congestion, haemorrhage, and an inflammatory exudate consiting of a massive aggregation of cosinophils together with lymphocytes and plasma cells. This was accompanied by a reduction in the proportion of side chain and C₄ substituted sialic acids.     

Histochemical studies of the mechanism of the periodic acid-phenylhydrazine-Schiff (PAPS) procedure

Summary Histochemical investigations of the periodic acid-phenylhydrazine-Schiff (PAPS) procedure were carried out on tissues containing carbohydrate macromolecules known to produce on periodate oxidation, only sialic acid monoaldehydes or hexosedialdehydes or mixtures of the two. The results indicated that the PAPS reaction is a generalized phenomenon independent of the hydrazine or hydrazide used, the nature of the Schiff reagent or the presence of anionic groups. It is proposed that phenylhydrazine condenses with periodate-engendered sialic acid monoaldehydes to yield the corresponding phenylhydrazone and with periodate-engendered dialdehydes to yield the corresponding morpholine or azido derivatives. Subsequent Schiff treatment results in the reversal of the blockade of sialic acid monoaldehydes but not of the dialdehydes, thus leading to selective Schiff staining of sialic acid residues.     

Semiterrestrial meiofauna inhabiting a wet campo in central Brazil, with special reference to the Copepoda (Crustacea)

The wet campo (campo úmido) marsh type is widely distributed in the cerrado region of central Brazil. These marshes develop on slopes along margins of gallery forests where the water table persists at or near the soil surface year-round. Their grass and sedge vegetation covers spongy, highly organic (not peaty) soils. Ground and surface water seeping through the wet campos tends to be slightly acidic (pH about 5), ion-poor (conductivity less than 10 µS cm^–1) and well oxygenated.A typical freshwater meiofaunal community develops in those wet campos where soils remain moist throughout the year (moisture content more than about 60% of soil wet weight). Such a community was studied from 1979–1982 in a wet campo in a protected natural area on the Fazenda Água Limpa of the Universidade de Brasília. It was dominated by nematodes, rotifers and harpacticoid copepods, and included protozoans, turbellarians, cyclopoid copepods, cladocerans, ostracods, oligochetes, hydracarines and several families of aquatic insect larvae. This community was most fully developed in the wetter areas.Species richness of the copepod community is the highest yet recorded in a freshwater system. The 29 species of harpacticoid copepods and 4 species of cyclopoid copepods displayed pronounced zonation which seemed best correlated with soil moisture content and water regime.     

Effects of phenytoin and flunarizine on the rise in extracellular potassium induced by repetitive stimulation of rat cerebral cortex

At a critical intensity of repetitive stimulation, [K+]0 in cerebral cortex increases rapidly to a "ceiling" value of 10-12 mM. Phenomena related to this rapid regenerative increase in [K+]0 were investigated using K+-sensitive microelectrodes. The critical intensity required to induce this rise was found to be increased by phenytoin (90 mg/kg preload + 30 mg/kg presurgery) but not by flunarizine (30 mg/kg preload + 10 mg/kg presurgery), when the stimulus (20 Hz, 0.4 ms pulse duration, 5 or 40 s train duration) was applied to a 1 mm2 area of parietal neocortex in alfentanil-anesthesized rats. Flunarizine and phenytoin appear to differ in their mechanisms of anti-epileptic action.     

Inheritance of human-erythrocyte Gerbich blood group antigens.

The blood group-antigenic determinant Gerbich was first described greater than 25 years ago, but its mode of inheritance has not been established. We performed protein immunoblotting by means of anti-beta sialoglycoprotein (SGP) and anti-gamma SGP reagents. The anti-beta SGP was a monoclonal antibody that reacts with normal beta SGP and with the abnormal beta-related SGPs associated with Gerbich and Yus types of Ge-negative red cells. In the families studied, we have shown that the products of the Ge alleles are inherited in an autosomal codominant manner.     

A beta-D-galactosidase from nasturtium (Tropaeolum majus L.) cotyledons. Purification, properties, and demonstration that xyloglucan is the natural substrate

beta-D-Galactosidase activity has been detected previously in the cotyledons of germinated nasturtium (Tropaeolum majus L.) seeds and has been linked to the hydrolysis in vivo of storage xyloglucan (amyloid) (Edwards, M., Dea, I. C. M., Bulpin, P. V., and Reid, J. S. G. (1985) Planta (Berl.) 163, 133-140). The major beta-D-galactosidase present in extracts from the cotyledons of 9-day seedlings has now been purified to apparent homogeneity. The enzyme (Mr 97,000, no subunits) comprised a range of closely related molecular species ranging in isoelectric point from pH 6.6 to 7.1. Further purification to give a single protein band on isoelectric focusing (pI = 7.1) was achieved by chromatofocusing. The pH optimum of the enzyme (mixed molecular species) was 4.0-5.0 (stable from pH 3-10), and the temperature optimum was 50 degrees C (stable to 50 degrees C). It hydrolyzed lactose and beta-D-galactopyranosides but not melibiose and alpha-D-galactopyranosides. It did not release the terminal nonreducing alpha-D-galactopyranosyl residues from seed galactomannans, but catalyzed the rapid removal of terminal nonreducing beta-D-galactopyranosyl residues from xyloglucans. On the basis of the ability of the enzyme to hydrolyze xyloglucans, the kinetics of xyloglucan hydrolysis, and an experimental demonstration of a clear correlation between xyloglucan depletion and the activity in vitro of this enzyme, it is argued that the cell-wall storage xyloglucan of the nasturtium seed is its natural substrate.     

Sequence-specific recognition of DNA: NMR studies of the imino protons of a synthetic RNA polymerase promoter

We have synthesized both strands of a DNA duplex containing the consensus Pribnow promoter sequence TATAATG , flanked by GC base pairs to stabilize the ends of the helix. The stability of this duplex has been studied by using 1H nuclear magnetic resonance. The imino protons have been assigned by using the sequential nuclear Overhauser effect approach. Exchange rates have been monitored by using selective inversion recovery measurements. The helix is relatively unstable in the center of the AT-rich region even when surrounded by GC base pairs, and there is considerable asymmetry in the melting of the helix.     

Sequence-specific recognition of DNA: assignment of nonexchangeable proton resonances in the consensus Pribnow promoter DNA sequence by two-dimensional NMR

The resonances of most of the nonexchangeable protons of both + and - strands of the consensus Pribnow dodecamer d( CGTTATAATGCG ) have been assigned by two-dimensional nuclear magnetic resonance methods. Application of the two-dimensional nuclear Overhauser effect ( NOESY ) sequential connectivity method, combined with two-dimensional autocorrelated ( COSY ) spectra to reveal scalar-coupled protons, results in assignment of virtually all of the base and sugar protons, except the sugar C5 protons which are inadequately resolved. Analysis of the nuclear Overhauser data indicates that the helix assumes a fairly uniform B form conformation.     

Optimization of solid-state fermentation for selective delignification of aspen wood with Phlebia tremellosa

The white-rot fungus Phlebia tremellosa can delignify aspen wood and increase the accessibility of its polysaccharides to enzymatic hydrolysis, under solid-state fermentation conditions. Fermentations at the 50 g scale were conducted to provide information for the design of larger fermentations. Agitation was not required. Forced aeration was needed for delignification of wood layers more than a few millimeters thick, but air circulation between the particles was not blocked by mycelium. Shavings were the best particles size. Sterilization of the wood was essential, but preadaptation of the inoculum to growth in wood was not. Inoculum levels as low as 2% were adequate.