Utilization of different carbon sources by bacteria isolated from the roots of pine seedlings (Pinus silvestris L.) inoculated with root-free, rhizosphere and mycorrhizosphere soil.

Studies were carried out on the utilization of different sugars (glucose, fructose, arabinose, xylose, sucrose) and organic acids (acetic, citric, fumaric, propionic, succinic) by fast and slow growing bacteria isolated from the roots of pine seedlings (P. silvestris L.) inoculated with root-free, rhizosphere and mycorrhizosphere soil from nursery and mature pine forest. Sucrose among sugars and propionic acid among organic acids were the less frequently utilized compounds. Sugars were better carbon sources than organic acids. Proportion of isolates utilizing respective sugars or organic acids was, in general, significantly higher among fast growing bacteria as compared with slow growing ones. No significant differences in number of strains assimilating the appropiate sugars depending on their original habitat or kind of soil were observed. Such differences were noted for utilization of some organic acids. 3-factor ANOVA confirmed that the growth speed of bacteria at the moment of their isolation had the strongest effect on utilization of the compounds studied.

Bacterial endobionts in the big non-mycorrhizal roots of Scots pine (Pinus sylvestris L.).

Subsurface bacterial growth occurred in an N-free medium inoculated with interior tissues of big non-mycorrhizal roots (7 to 8 mm diameter) of 15-20 years-old Scots pine (Pinus sylvestris L.) growing on sand dunes at the Baltic Sea of Poland. The bacteria were not N2 fixers as determined by the acetylene reduction method. Light microscopic and scanning electron microscopic observations revealed massive bacterial clusters residing in the cortical cells underlying epidermis and parenchyma. The bacteria produced yellow-green pigments on King's medium, which fluoresced under ultraviolet (UV) irradiation at 366 nm wavelength, and could be a siderophore-producing Pseudomonas.

Production of B-group vitamins by Azospirillum spp. grown in media of different pH at different temperatures.

Studies were carried out on B-group vitamin (thiamine, biotin, nicotinic acid, riboflavin, pantothenic acid) production by 3 strains of Azospirillum (one derived from coniferous ectomycorrhizae and two--from sporocarps of ectomycorrhizal fungi) grown in media of different pH (5.5, 6.5, 7.5) at different temperatures (10 degrees C, 20 degrees C, 26 degrees C). Riboflavin was produced in largest amounts by all the strains studied; biotin was not detected in culture filtrates at all. Qualitative-quantitative composition of vitamins in post culture liquids of azospirilla depended on the temperature of growth, pH of the medium and on the strain studied. Thiamine was synthesized in largest quantities at pH 5.5 by all strains of Azospirillum--independently of the temperature of growth. In media of higher pH this vitamin was detected in considerably smaller amounts or was not detected at all. The smallest quantities--and the smallest numbers of vitamins produced were observed at temperature 10 degrees C and pH 5.5.

Growth of mycorrhizal fungi in dixenic cultures with bacteria in media of different composition.

Studies were carried out on the effect of bacteria: Arthrobacter globiformis, Bacillus subtilis and Pseudomonas fluorescens on biomass production by three important ectomycorrhizal fungi: Laccaria laccata, Hebeloma crustuliniforme and Rhizopogon vinicolor in media of different composition. It was shown that bacteria stimulated, inhibited or did not affect significantly the biomass production by mycorrhizal fungi. 3-factor ANOVA have shown that although effect of bacteria was statistically significant (p < or = 0.05), composition of medium and its pH affected mycelial growth stronger than bacteria.

Free amino acids production by ectomycorrhizal fungi of pine (Pinus sylvestris L.).

Studies on free amino acids production by five species of ectomycorrhizal fungi (Amanita muscaria, Suillus granulatus, Suillus luteus, Suillus bovinus and Rhizopogon luteolus) show that all the fungi produced mainly: glutamic acid, leucine, lysine, ornithine, arginine and an unidentified ninhydrin-positive compound X3. Both the quality and quantity of amino acids released was different in the fungal species studied. The predominant amino acids in post-culture liquids in general did not exceed 1.5 micrograms/mg dry mass.

Production of B-group vitamins by bacteria isolated from soil, rhizosphere, and mycorrhizosphere of pine (Pinus sylvestris L.).

Studies on the production of B vitamins by soil, rhizosphere, and mycorrhizosphere bacteria have revealed that such ability is common among these organisms. Thiamin, nicotinic and folic acids were produced by the greatest number of bacteria. Bacteria isolated from the rhizosphere and mycorrhizosphere produced more riboflavin than those originating from the soil distant from roots. In general the soil strains produced higher amounts of vitamins (except riboflavin) than the root-zone isolates. Two and three vitamins were produced by the majority of bacteria. The synthesis of four and five vitamins was found in few strains only.

Production of cytokinin-like substances by mycorrhizal fungi of pine (Pinus sylvestris L.) in cultures with and without metabolites of actinomycetes.

Studies on the effect of post culture liquids of actinomycetes on cytokinin-like substances production by mycorrhizal fungi have revealed that actinomycete metabolites inhibited or stimulated the synthesis of these compounds. The results of chromatographic analyses suggest, that substances stimulating the soybean callus are likely to be: riboside 6 (gamma, gamma-dimethylallylamino) purine and riboside zeatin. Using gas chromatography it was confirmed that both substances are produced by Rhizopogon luteolus. Paxillus involutus synthesizes probably besides the two substances also zeatin, as appears from the data obtained by column chromatography.

Effect of pH on production of cytokinin-like substances by bacteria isolated from soil, rhizosphere and mycorrhizosphere of pine (Pinus silvestris L.).

Cytokinin-like substances were produced in higher amounts by soil isolates than by those isolated from the rhizosphere and mycorrhizosphere. However more bacterial strains isolated from the rhizosphere and mycorrhizosphere were capable of synthesizing cytokinin-like compounds. A distinct effect of pH on the production of these substances was found. It is suggested that zeatin and zeatin riboside are likely to be among the cytokinin-like substances detected.

The synthesis of cytokinin-like substances by coryneform bacteria isolated from the roots of pine seedlings (Pinus silvestris L.).

Seven of ten strains studied produced cytokinin-like substances, mainly in 7 day old cultures. The cytokinin-like substances were most often located on chromatograms at Rf values 0.8 to 0.9, rarely at Rf 0.6 to 0.7.

Manometric studies with bottom sediments of three lakes.

Studies were carried out on metabolic activity of microorganisms inhabiting the bottom sediments of three lakes of different trophy. For respirometric studies the Warburg apparatus was used. Oxygen uptake was different in various sediment samples supplemented with organic substances, depending on the source and time of sampling. Cystein, aspartic acid and intermediates of the tricarboxylic acids cycle were oxidized most readily. Carbohydrates and especially maltose, celobiose, galactose, and glucose were metabolized less willingly.

Synthesis of auxins from tryptophan and tryptophan-precursors by fungi isolated from mycorrhizae of pine (Pinus silvestris L.).

Fungi isolated from mycorrhizae of pine required tryptophan for auxin synthesis. More auxins were found in culture grown with pyrogallol than in those without this compound. The fungi studied produced also auxins from other than tryptophan compounds. Indole employed with serine was more suitable for the production of auxins than indole or anthranilic acid used separately. The active compounds showing auxin activity were located on the chromatograms at Rf 0.2--0.4 and 0.3--0.5 with the solvent system isopropanol, ammonia, water (10:1:1 v/v).

Effect of the culture medium and incubation time on auxins production by bacteria isolated from the roots of pine seedlings (Pinus silvestris l.).

Studies were performed on the effect of culture medium and incubation time on the production of auxins by bacteria. The bacteria studied produced more auxins in the mineral medium containing glucose and tryptophan than in that enriched with casamino acids and yeast extract. The amount of auxins elaborated depended both upon the strain and the age of the culture. Some strains produced the largest amounts of these substances after 7 days of incubation while others required a longer period. Most of the substances showing auxin activity were located on the chromatograms at Rf 0.3-0.4 and 0.8-1.0.

Synthesis of auxins by fungi isolated from the roots of pine seedings (Pinus silvestris L.) and from soil.

Synthesis of auxins by fungi grown with and without tryptophan has been studied. 26 out of 30 fungal strains produced detectable amounts of auxins in tryptophan contain media. 18 strains produced but very small amounts of auxins in media without this amino acid. By means of paper chromatography, chromogenic reagents and biotest three active substances could be distinguished. They were found on the chromatograms run with isopropanol, ammonia, water (10:1:1 v/v) at Rf 0.05--0.2, 0.3--0.5 and 0.8--1.0. Most strains produced active substances with Rf 0.3--0.5.

Studies on metabolic activity of planktonic bacteria isolated from three lakes.

Studies were carried out on metabolic activity of 480 bacterial isolates on 9 substrates. All bacterial isolates studied except one utilized the casamino acids. Also with casamino acids the highest oxygen uptake values were obtained. Among the carbohydrates, glucose was most frequently utilized by the planktonic bacteria. Bacteria isolated from water of the various lakes differed in their metabolic activity as well as in the capability of utilizing the individual substrates. The capability of attacking by the bacteria the substrates applied depended largely upon the time of their isolation.

Production of auxins by bacteria isolated from the roots of pine seedlings (Pinus silvestris L.).

Qualitative and quantitative studies were carried out on the production of auxins by Coryneform bacteria, the only bacterial types isolated from roots of pine seedlings. Almost all isolates were capable of producing auxins in tryptophan containing media. In media without this amino acid only trace or no auxins were produced. Most of the bacteria studied synthesized auxins located on the chromatograms run with isopropanol, ammonia, water (10:1:1 v/v) at Rf 0.3--0.5. Moreover substances with Rf values 0.05--0.2 and 0.8--1.0 were produced by some strains. No plant growth inhibitors detected with the Avena coleoptiles biotest were produced by the bacteria studied.

Production of gibberellin-like substances by fungi isolated from mycorrhizae of pine (Pinus silvestris/L.).

Gibberellin-like substances were found to be produced by fungi isolated from mycorrhizae of pine. Among the isolates studied gibberellin-like substances producers were most numerous among the Basidiomycetes forming ectotrophic mycorrhiza and among non-sporulating fungi forming no mycorrhiza. In most strains the gibberellin-like subtances were elaborated after 10--20 days of incubation. The Rf values of the gibberellin-like compounds were different in various strains, but in most of them substances showing gibberellin activity appeared on the chromatograms run with benzene, acetic acid (10:3 v/v) at Rf 0.2--0.6.

Production of gibberellin-like substances by bacteria and fungi isolated from the roots of pine seedlings (Pinus silvestris L.).

The production of gibberellin-like substances by bacteria and fungi was investigated. A considerable number of the microorganisms studied produced these substances (55 and 86% of bacterial and fungal isolates respectively). Most of the organisms tested synthesized biologically active substances located on the chromatograms with the solvent system benzene, acetic acid (10:3 v/v) at Rf 0.05--0.3. The ammount of gibberellin-like substances produced varied in the range 0.00007--0.00065 GA3 equivalents mug/ml in bacteria and 0.00014--0.00118 mug/ml in fungi.