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Dinitrogen fixation activity was determined directly on experimental plots in mixtures of grass with red and white clover in the year of sowing as well as in the first year of full utilisation using the method of acetylene reduction (ARA). Furthermore, numbers of bacteria, actinomycetes, fungi and Azotobacter sp. were determined in soils under the experimental mixtures.
Fifteen species of wild mushrooms and underlying soil samples collected in a virgin landscape of Augustowska Forest in northeastern Poland in 1997-98 were analyzed for total mercury to evaluate the status of contamination and usefulness of higher mushrooms as possible bioindicators of mercury pollution. Among the 15 species analyzed, Pinewood King Bolete, Scaly Tooth and King Bolete showed relatively high bioconcentration factors (BCF: dry-weight normalized concentrations of mercury in mushrooms relative to concentrations in soil) for mercury, which varied between 69 and 110. These three species were also characterized by great concentrations of total mercury in caps (between 2,000 +/- 800 and 2,300 +/- 1,100 ng g-1 dry wt) and stalks (between 850 +/- 390 and 1,000 +/- 500 ng g-1 dry wt.). Species such as Red-hot Milk Cap, Poison Pax and Common Chantherelle had mercury BCFs of less than 1, while Gipsy Bolete, Orange Birch Bolete, Brown Scaber Stalk, Variegated Bolete, Sandy Knight-cap and Yellow-cracking Bolete were weak or moderate mercury accumulators with BCFs between 1 and 40. Concentrations of mercury in mushrooms were greater than the tolerance limits suggested for mercury in plant foods.
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Actinomadura cultures were isolated from soil samples collected in Turkmenistan, the Moscow, Kursk and Volgograd regions. The cultures were described as representatives of a new species (Actinomadura recticatena, Preobrazhenskaya et Galatenko, sp. nov). The hydrolysates of intact cells of the cultures contain mesodiaminopumelic acid, galactose and madurose. The species is characterized by straight spore chains, wrinkled spore surface, cream-colored aerial mycelium and brown substrate mycelium with pinkish or slightly violet shade. The cultures produce no soluble pigments, including the melanoid ones. The red-violet fraction of the pigments responsible for the pinkish and violet shades of the substrate mycelium belongs to the antibiotics of the griseorodin-rubromycin group.
A Streptomyces sp. isolated from riverbank soil in Manitoba, Canada, was found to contain two cancer cell growth inhibitories: diazaanthraquinone 1 and 3-(hydroxyacetyl)indole (8). The structures were determined by interpretation of data from HRMS, UV, and high-field (400 MHz) NMR experiments. The red-colored diazaanthraquinone 1 and 3-(hydroxyacetyl)indole (8) were found to inhibit (0.1-3 microg/mL) growth of a minipanel of human cancer cell lines and P388 lymphocytic leukemia cells. Diazaanthraquinone 1 was also found to inhibit growth of the bacteria Streptococcus pneumoniae and Neisseria gonorrheae. However, three companion constituents, cyclo-Pro-Leu (5), cyclo-Pro-Phe (6), and cyclo-Pro-Val (7), did not inhibit cancer cell growth.
Lead concentrations were measured in boiled, mashed potatoes and in baked potatoes that had been prepared and cooked in domestic kitchens. Levels of lead in the boiled, mashed potatoes ranged from below the 1 microgram/kg limit of detection up to 18 micrograms/kg with a mean of 6 micrograms/kg (wet weight). In the large majority of cases the lead in the tap water was the predominant source of the metal. Higher amounts of lead (range 11 micrograms/kg to 56 micrograms/kg, mean 27 micrograms/kg) were present in baked potatoes and this was attributed to soil adhering to the potato skin. The extent of leaching of lead from bone during cooking has also been investigated. For beef stocks there was little evidence to suggest that significant migration of bone lead occurred. For beef casseroles, marinaded in red wine, some leaching did occur from beef joints containing elevated amounts of bone lead; however the levels were all below 350 micrograms/kg and, on average, less than double that found in casseroles prepared from normal joints where the bone lead levels were an order of magnitude less.
The upper elevational limits of tree species are thought to be controlled by abiotic factors such as temperature and the soil and atmospheric conditions affecting plant water status. We measured relative water contents (RWC), water potentials (Psi) and cuticular conductances (g(c)) of shoots of four conifer species-eastern hemlock (Tsuga canadensis (L.) Carr.), eastern white pine (Pinus strobus L.), red pine (P. resinosa Ait.) and red spruce (Picea rubens Sarg.)-during two winters on Mt. Ascutney, Vermont, USA. Some micrometeorological measurements are also reported. Eastern hemlock and white pine were studied near their upper elevational limits at a 640-m site, and red pine was studied near its upper elevational limit at 715 m. Red spruce was also studied at the 715-m site, which is in the middle of its elevational range on this mountain. There was no evidence of winter desiccation stress in any species. The observed distribution of seedlings suggested that the upper elevational limits on shade-intolerant eastern white pine and red pine are set by the absence of suitable seed beds after 100 years without fire. Eastern hemlock is able to reproduce in deep shade on organic substrates, but germination at high elevations may be restricted by low temperatures.
Red-orange Mycobacterium species (the rhodochrous group) were isolated from the water of the Arctic regions; they were described, and the structure of lipids and the assimilation of oil products of low temperatures were comparatively studied in the arctic water and soil Mycobacterium species. The composition of usual fatty and mycolic acids was studied in two strains growing in a medium with hexadecane. Palmitic acid prevailed among fatty acids in the both strains; mycolic acids were represented by the compounds C34:0 and C34:1 (Mycobacterium brevicale) and C32:0 and C:34:0 (Mycobacterium sp.). The presence of unsaturated mycolic acids in the cells correlated with their capability to assimilate hydrocarbons at low temperatures.
DL-beta-aminobutyric acid (BABA) is a non-protein amino acid that is an effective inducer of resistance against a variety of plant pathogens. However, examples of BABA-induced resistance against insect herbivores have not been reported. We applied BABA as a soil drench to legumes and monitored its effects on the pea aphid Acyrthosiphon pisum (Harris). On tic bean (Vicia faba var. minor), BABA increased aphid mortality, caused a reduction in the mean relative growth rate of individual insects and lessened the intrinsic rate of population increase (rm). BABA also caused significant reductions in the growth rate of A. pisum on pea (Pisum sativa), broad bean (Vicia faba var. major), runner bean (Phaseolus coccineus), red clover (Trifolium pratense) and alfalfa (Medicago sativa). No direct toxic effects of BABA against A. pisum were found, and no phytotoxic effects that may have caused a reduction in aphid performance were detected. Possible mechanisms behind this BABA-induced inhibition of aphid performance are discussed.
Stem respiration was measured throughout 1993 on 56 mature trees of three species (Quercus alba L., Quercus prinus L., and Acer rubrum L.) in Walker Branch Watershed, Oak Ridge, Tennessee. A subset of the trees was remeasured during 1994. Diameter increments, stem temperatures and soil water were also monitored. Respiration rates in the spring and summer of 1993 tracked growth rate increments, except during a drought when growth dropped to zero and respiration increased to its highest rate. During the dormant season, rates of total stem respiration (R(t)) tended to be greater in large trees with thick sapwood but no such trend was observed during the growing season. Before and after the growing season, respiration rates correlated well with stem temperatures. Estimated values of Q(10) were 2.4 for the two oak species and 1.7 for red maple. The Q(10) values were used along with baseline respiration measurements and stem temperatures to predict seasonal changes in maintenance respiration (R(m)). In red maple, annual total R(m) accounted for 56 and 60% of R(t) in 1993 and 1994, respectively. In chestnut oak, R(m) accounted for 65 and 58% of R(t) in 1993 and 1994, respectively. In white oak, R(m) accounted for 47 and 53% of R(t) in 1993 and 1994, respectively. Extrapolating these data to the stand level showed that woody tissue respiration accounted for 149 and 204 g C m(-2) soil surface year(-1) in 1993 and 1994, respectively.
Ralstonia metallidurans CH34 (formerly Alcaligenes eutrophus CH34) is a soil bacterium characteristic of metal-contaminated biotopes, as it is able to grow in the presence of a variety of heavy metals. R. metallidurans CH34 is reported now to resist up to 6 mM selenite and to reduce selenite to elemental red selenium as shown by extended X-ray absorption fine-structure analysis. Growth kinetics analysis suggests an adaptation of the cells to the selenite stress during the lag-phase period. Depending on the culture conditions, the medium can be completely depleted of selenite. Selenium accumulates essentially in the cytoplasm as judged from electron microscopy and energy-dispersive X-ray analysis. Elemental selenium, highly insoluble, represents a nontoxic storage form for the bacterium. The ability of R. metallidurans CH34 to reduce large amounts of selenite may be of interest for bioremediation processes targeting selenite-polluted sites.
The different response to growth on serpentine soil is a major autecological difference between the annual asteracean species Microseris douglasii and M. bigelovii, with nearly non-overlapping distribution ranges in California. Early flowering and seed set is regarded as a crucial character contributing to escape drought and thus is strongly correlated with survival and reproductive success on serpentine as naturally toxic soil. M. bigelovii (strain C94) from non-serpentine soil produces more leaves at the expense of bud production in the first growing phase than M. douglasii (B14) from serpentine soil. A QTL mapping study for this trade-off and for other growth-related traits was performed after six generations of inbreeding (F7) from a single interspecific hybrid between B14 and C94 on plants that were grown on serpentine and alternatively on normal potting soil. The trade-off is mainly correlated with markers on one map region on linkage group 03a (lg03a) with major phenotypic effects (phenotypic variance explained [PVE] = 18.8 - 31.7 %). Plants with the M. douglasii allele in QTL-B1 (QTL-NL1) produce more buds but fewer leaves in the first 119 days on both soil types. Three modifier QTL could be mapped for bud and leaf production. In one modifier (QTL-B2 = QTL-NL4) the M. douglasii allele is again associated with more buds but fewer leaves. QTL mapped for bud set in the F6 co-localize with QTL-B1 (major QTL) and QTL-B3. Two additional QTL for leaf length and red coloration of leaves could be mapped to one map region on lg03a. Co-localization of the two QTL loci with major phenotypic effects on bud and leaf production strongly suggests that a major genetic locus controls the trade-off between the two adaptive traits. The importance of mutational changes in major genes for the adaptation to stressful environments is discussed.
Six bacterial strains (BT523T, BT559T, 15J16-1T3BT, BT730T, DG25AT, and DG25BT) were isolated from soil samples in Korea and assigned to the family Hymenobacteraceae (order Cytophagales, class Cytophagia). Phylogenetic analysis based on 16S rRNA gene sequences showed that the strains formed distinct lineages within the genus Hymenobacter. Strains BT523T, BT559T, and 15J16-1T3BT exhibited highest sequence similarities to Hymenobacter armeniacus BT189T (97.6%), Hymenobacter polaris RP-2-7 T (97.8%), and Hymenobacter paludis KBP-30 T (98.3%), respectively, while strains BT730T, DG25AT, and DG25BT were most closely related to Hymenobacter tibetensis XTM003T, with similarities of 96.3-96.6%. All strains were Gram-negative, aerobic, rod-shaped, and formed red to pink pigmented colonies. Whole-genome analysis revealed genome sizes ranging from 3.78 to 6.33 Mb with G + C contents of 55.5-65.0%. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the strains and their closest relatives were below the accepted thresholds for species delineation, supporting their classification as novel species. Functional annotation indicated the presence of genes associated with core metabolism, stress response, and pigment biosynthesis, reflecting adaptation to soil environments. Secondary metabolite analysis further revealed the presence of biosynthetic gene clusters, including terpene and siderophore pathways. Based on polyphasic taxonomic evidence, the six strains are proposed to represent six novel species of the genus Hymenobacter, for which the names Hymenobacter miniatus sp. nov., Hymenobacter madidus sp. nov., Hymenobacter convexus sp. nov., Hymenobacter rubellus sp. nov., Hymenobacter erythromyxa sp. nov., and Hymenobacter radioresistens sp. nov. are proposed. The type strains are BT523T (= KCTC 72341 T = NBRC 114851 T), BT559T (= KACC 21821 T = NBRC 114852 T), 15J16-1T3BT (= KCTC 42995 T = NBRC 112818 T), BT730T (= KACC 22457 T = NBRC 116482 T), DG25AT (= KCTC 32451 T = TBRC 19856 T), and DG25BT (= KCTC 32452 T = JCM 19444 T).
The sampling procedures in connection with a very sensitive analytical method are described. Results from different areas in Austria are presented and an interpretion of the results is attempted. Some findings are in accordance with measurements from other substances, some are not. The differences most probably depend on several factors like soil type, precipitation, migration of strontium-90, concentration of stable strontium and calcium. No significant rise in the concentration could be found after 1986 thus in accordance with other measurements of strontium-90 contamination after the Chernobyl accident.
Seven years of winter survival data for winter wheat ( Triticum aestivum L.) were collected on a loam soil located on the Central Experimental Farm at Ottawa, Ontario (45 degrees 23'N, 75 degrees 43'W). The site was low-lying and subject to frequent winter flooding and ice-sheet formation. Two cultivars, a soft white and a hard red winter wheat, were planted in September. Crop establishment was measured in late fall and the percentage survival was measured in April of the following year. Meteorological data, which were available from the nearby weather site, were used to develop a large set of monthly weather indices that were felt to be important for winter survival. The objective of the study was to use genetic selection algorithms and artificial neural networks to select a subset of critical weather factors and topographic features and to model winter survival. The six weather indices selected were the total rain depth for December (mm), the total rain depth for February (mm), the number of days of the month with snow on the ground for January, the extreme minimum observed daily air temperature for March ( degrees C), the number of days of the month with snow on the ground for March, and the number of days of April with a daily maximum air temperature greater than 0 degrees C. It was found 89% of the variation in winter survival could be explained by these six weather indices, the cultivar, elevation and plot location.
A new antibiotic complex has been obtained from the cultures of an actinomycete, strain FA-1180, isolated from a soil sample collected at lake side of Biwa in Japan. On the basis of taxonomic studies the producing microorganism is designated as Actinomadura roseoviolacea var. biwakoensis nov. var. The antibiotic complex belongs to the class of anthracycline glycoside antibiotics. All components form deep red fine needles on crystallization; components are named rubeomycin A, A1, B and B1. These components exhibit activity against Gram-positive bacteria as well as Yoshida sarcoma cell in vitro. These components are also effective on P388 leukemia.
Ten years after the Chernobyl accident a physiological condition of cows was examined on radioactivy contaminated territory of the Novozibkov district of the Bryansk region. The long grazing of cattle on radioactivly contaminated territory revealed the increase in permeability of plasmatic membrane of the red blood cells to Ca2+ and the activation of process of lipid peroxidation. The sensitivity of the red blood cells of cows to incubations in hypertonic conditions was demonstrated.
The effect of Cu pollution on the Cu uptake by wheat, the characteristics of chlorophyll concentration, and the visible-near infrared spectra were studied under the condition of solution culture, and the relationships among the three indices were discussed. The results indicate that the content of Cu in TritiZnm aestivum L. increases and the concentration of chlorophyll reduces with the increase of Cu in solution. The spectral characteristics also take on the disciplinary diversification (the spectral reflectivity ascended in the visible light band and decreased in the near infrared band; the range of red edge shift decreased) with the increase of Cu in solution.