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PubMed1967

The Expression of Interionic Relationships in Pinus elliottii.

The effects of factorial combinations of N, P and Mg on some of the interrelationships among nutrient ions as they occurred in seedlings of slash pine were investigated. In similar studies, true interactions have not always been differentiated from apparent interactions, the result of comparing foliage concentrations in plants with widely divergent growth rates. To prevent this, nutrient solutions were formulated to produce conditions ranging only from slight deficiency through luxury consumption. This relatively narrow range of nutrition allowed actual interactions to be separated from those changes in foliage concentration that are primarily a result of large differences in growth.The needles were analyzed for total and soluble N and total P, K, Ca, Mg and Na. Each level of each nutrient variable had a significant effect on the concentration of 1 or more dissimilar elements. The familiar depressive effect of N on foliar P was observed; however this relationship was shown to be primarily the result of growth dilution rather than anion antagonism. Increased Mg did antagonistically reduce the uptake of Ca and, generally, K. Increments of P not required for growth stimulated uptake of N, Ca, Mg and K. No relationship was found between Mg supply and P accumulation.

Journal Article↗
PubMed1988

Isocitrate lyase from Pinus pinea. Characterization of its true substrate and the action of magnesium ions.

We found that the Mg-isocitrate complex is the true substrate for pine isocitrate lyase and that magnesium acts as a non-essential activator. Both the non-activated and the activated enzyme forms are catalytically active. Our model is consistent with the presence of two Mg-binding sites with different affinities: an activator site with high affinity in addition to the catalytic site with lower affinity. This may result in a complex, fine regulation of isocitrate lyase activity by magnesium. The affinity of the free enzyme for isocitrate is very low. Moreover, free isocitrate does not bind to the activated enzyme, nor it can yield a catalytically active form by binding to an enzyme species whose catalytic site has already been bound by magnesium.

Binding Sites↗
PubMed1992

Efficient fermentation of Pinus sp. acid hydrolysates by an ethanologenic strain of Escherichia coli.

Process conditions for the acid hydrolysis of pine hemicellulose and cellulose have been described which provide a biocompatible sugar solution. By using an improved strain of recombinant Escherichia coli, strain KO11, hydrolysates supplemented with yeast extract and tryptone nutrients were converted to ethanol with an efficiency of 85% to over 100% on the basis of monomer sugar content (approximately 72 g/liter) and with the production of 35 g of ethanol per liter in 48 h. In the process described, approximately 347 liters of ethanol could be produced per dry metric ton of lignocellulose.

Cellulose↗
PubMed1975

Microbial utilization of Pinus radiata bark.

A screening program using suspensions of ground bark in mineral salts media, or extracts prepared from ground bark by treating with hot water, sulfuric acid, ammonium hydroxide, or sodium hydroxide, yielded more than 200 pure cultures of fungi, yeasts, and bacteria. Only 38 of these have good growth on liquid bark media. All were filamentous fungi, although many bacteria and yeasts were among the cultures that failed to give appreciable growth. Species of Penicillium, Scopulariopsis, Aspergillus, Trichoderma, Cladosporium, and Fusarium were among the most actively growing cultures. Cell biomass yields, as measured by cell nitrogen determination, were too low for economic production of single cell protein.

Bacteria↗
PubMed1975

Quantitative assessment of the bacterial rhizosphere flora of Pinus contorta var. latifolia.

The bacterial flora associated with root systems of young and mature lodgepole pine was investigated by sampling forest-grown trees. Counts were performed and expressed on a surface-area basis to give a more realistic comparison of organism density or activity within the control soil, rhizosphere soil, and rhizoplane. On this basis, densities increased by an order of 10(4)- to 10(6)-fold from control soil to rhizoplane, with the degree of stimulation being inversely related to root radius.

Bacteria↗
PubMed1999

Effect of procyanidins from Pinus maritima on glutathione levels in endothelial cells challenged by 3-morpholinosydnonimine or activated macrophages.

The effects of reactive nitrogen species on glutathione homeostasis in human endothelial ECV 304 cells challenged by 3-morpholinosydnonimine-N-ethylcarbamide (SIN-1) on RAW 264.7 activated macrophages using a co-culture model were investigated. SIN-1 or macrophages activated by lipopolysaccharide plus interferon-gamma induced a significant glutathione decrease in ECV 304 cells. Pre-incubation of ECV 304 cells with French maritime pine bark extract containing mainly oligomeric procyanidins protected endothelial cells from activated macrophage-induced glutathione depletion. Data demonstrate that reactive nitrogen species generated with different kinetics and mechanisms impair glutathione levels in endothelial cells, and that pine bark extract significantly enhances antioxidant defenses.

Animals↗