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1.
The changes in foliar concentrations of volatile terpenes in response to water stress, fertilization and temperature were
analyzed in Pinus halepensis and Quercus ilex. The most abundant terpenes found in both species were α-pinene and Δ3-carene. β-Pinene and myrcene were also abundant in both species. P. halepensis concentrations were much greater than those of Q. ilex in agreement with the lack of storage in the latter species (15205.60 ± 1140.04 vs. 0.54 ± 0.08 μg g−1 [d.m.]). The drought treatment (reduction to 1/3 of full watering) significantly increased the total terpene concentrations
in both species (54% in P. halepensis and 119% in Q. ilex). The fertilization treatment (addition of either 250 kg N ha−1 or 250 kg P ha−1 or both) had no significant effects on terpene foliar concentrations. The terpene concentrations increased from 0.25 μg g−1 [d.m.] at 30°C to 0.70 μg g−1 [d.m.] at 40°C in Q. ilex (the non-storing species) and from 2,240 μg g−1 [d.m.] at 30°C to 15,621 μg g−1 [d.m.] at 40°C in P. halepensis (the storing species). Both species presented negative relationship between terpene concentrations and relative water contents
(RWC). The results of this study show that higher terpene concentrations can be expected in the warmer and drier conditions
predicted for the next decades in the Mediterranean region. 相似文献
2.
Jang K. Kim George P. Kraemer Christopher D. Neefus Ik Kyo Chung Charles Yarish 《Journal of applied phycology》2007,19(5):431-440
Porphyra is one of the world’s most valued maricultured seaweeds and has been cultivated for several hundred years in Asia. The objective
of this study was to produce critical information as a guide for the selection of an appropriate Porphyra species from coastal New England for the development of a land-based aquaculture system. Four Northwest Atlantic Porphyra species: P. leucosticta,
P. amplissima, P. linearis and P. umbilicalis, were cultivated for 1 and 2 weeks at saturated light intensities (100–150 μmol photons m−2s−1) and six combinations of ammonium (25 and 250 μmoles L−1) and temperature (10, 15 and 20°C). Specific growth rate (SGR) increased with decreasing temperature in P. leucosticta, P. linearis and P. umbilicalis and increased with increasing temperature in P. amplissima. The SGR of all species was greater at the higher ammonium concentration. Porphyra linearis had the highest SGR, increasing in biomass by approximately 16% day−1. Phycoerythrin (PE) content was higher at 10°C and 250 μmoles L−1 in all species except P. amplissima. The PE content, measured as fresh weight (FW), of P. linearis (29 mg g−1 FW−1) and P. umbilicalis (26 mg g−1 FW−1) was significantly higher than the other two species. Tissue nitrogen content of all species measured in dry weight was on
average 1.45% higher at 250 μmoles L−1 than at 25 μmoles L−1 ammonium concentration. Porphyra umbilicalis had the highest tissue nitrogen contents (6.76%) at 10°C and 250 μmoles L−1 ammonium. Based on these results, P. linearis and P. umbilicalis should be considered as potential candidates for bioremediation with finfish and shellfish mariculture. 相似文献
3.
Nitraria retusa and Atriplex halimus (xero-halophytes) plants were grown in the range 0–800 mM NaCl while Medicago arborea (glycophyte) in 0–300 mM NaCl. Salt stress caused a marked decrease in osmotic potential and a significant accumulation of
Na+ and Cl− in leaves of both species. Moderate salinity had a stimulating effect on growth rate, net CO2 assimilation, transpiration and stomatal conductance for the xero-halophytic species. At higher salinities, these physiological
parameters decreased significantly, and their percentages of reduction were higher in A. halimus than in N. retusa whereas, in M. arborea they decreased linearly with salinity. Nitraria retusa PSII photochemistry and carotenoid content were unaffected by salinity, but a reduction in chlorophyll content was observed
at 800 mM NaCl. Similar results were found in A. halimus, but with a decrease in the efficiency of PSII (F′v/F′m) occurred at 800 mM. Conversely, in M. arborea plants we observed a significant reduction in pigment concentrations and chlorophyll fluorescence parameters. The marked
toxic effect of Na+ and/or Cl− observed in M. arborea indicates that salt damage effect could be attributed to ions’ toxicity, and that the reduction in photosynthesis is most
probably due to damages in the photosynthetic apparatus rather than factors affecting stomatal closure. For the two halophyte
species, it appears that there is occurrence of co-limitation of photosynthesis by stomatal and non-stomatal factors. Our
results suggest that both N. retusa and A. halimus show high tolerance to both high salinity and photoinhibition while M. arborea was considered as a slightly salt tolerant species. 相似文献
4.
Abdolmohammad Abedian Kennari Nasrollah Ahmadifard Maryam Fallahi Kapourchali Jafar Seyfabadi 《Biologia》2008,63(3):407-411
The rotifer, Brachionus calyciflorus, was grown with two algae species (Chlorella sp. and Scenedesmus obliquus) at different concentrations (0.1, 1 and 10 × 106 cells ml−1). The body size (lorica biovolume) of individual rotifer and their egg size were measured when the populations were roughly
in the exponential phase of population growth. The body size of the rotifers differed significantly (P < 0.05) among the two algae species used, however this effect was not observed for egg size. The body size of rotifers fed
on higher densities of Chlorella sp. (10 × 106 cells ml−1) was significantly larger than for those fed on lower and medium densities (0.1 and 1 × 106 cells ml−1). Body size and egg size of rotifers fed with different amounts of Scenedesmus did not differ significantly. The egg size was significantly larger at higher food level of Chlorella. A significantly positive correlation was observed between the adult rotifer body size and their egg size. 相似文献
5.
K. M. Pagenkopp J. Klicka K. L. Durrant J. C. Garvin R. C. Fleischer 《Conservation Genetics》2008,9(6):1577-1588
Our current understanding of migration routes of many birds is limited and researchers have employed various methods to determine
migratory patterns. Recently, parasites have been used to track migratory birds. The objective of this study was to determine
whether haemosporidian parasite lineages detect significant geographic structure in common yellowthroats (Geothlypis trichas). We examined liver tissue or blood from 552 birds sampled from multiple locations throughout the continental United States,
southern Canada, and the Bahamas. We found a 52.7% overall prevalence of haematozoan infection. We identified 86.1% of these
infections to genus: 81% were Plasmodium; 5% were Haemoproteus; and 0.1% were Leucocytozoon. There were significant differences in the prevalence of different parasite genera among regions (χ2 = 36.82, P < 0.0001) and in the proportion of Plasmodium infections versus other parasites among regions (χ2 = 35.52, P < 0.0001). Sequence information identified three Haemoproteus lineages, two Leucocytozoon lineages, and thirteen Plasmodium lineages. Due to the low number of Haemoproteus and Leucocytozoon, only Plasmodium lineages were used in the geographic comparison of lineages. Six Plasmodium lineages were found in eight or more birds and the prevalence of these varied significantly among regions (χ2 = 172.33, P < 0.0001). Additionally, 45 juvenile birds were sampled to determine what parasites could be obtained in the breeding grounds
and we found only one lineage. In conclusion, parasite lineages show some geographic structure, with some lineages being more
geographically specific than others, but are not useful for determining migratory connectivity in this species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
6.
Summary
Dendrobium candidum Wall. Ex Lindl. is an important species used in the formulation of Shih-hu, a Chinese traditional medicine. An efficient
protocol for in vitro propagation of D. candidum using the axenic nodal segments of the shoots, originated from the in vitro germinated seedlings, was developed. The seeds from 120-d-old capsules after pollination were first germinated on half-strength
Murashige and Skoog (MS) basal medium supplemented with 30 g l−1 sucrose. After 4 mo., the seedlings were subcultured on a similar medium supplemented with 1 ml l−1 HYPONeX, 80 g l−1 potato homogenate and 2 g l−1 activated charcoal for further growth. Axenic nodal segments excised from 9-mo.-old seedlings were cultured on the medium
in the presence of 2 mg l−1 benzyladenine (BA) and 0.1 mg l−1 naphthaleneacetic acid (NAA). After 75 d, 73.2% of the explants gave rise to buds/shoots. The elongated shoots were rooted
on the medium containing 0.2 mg l−1 NAA and the plantlets were successfully acclimatized in soil. 相似文献
7.
Y. Kitaya L. Xiao A. Masuda T. Ozawa M. Tsuda K. Omasa 《Journal of applied phycology》2008,20(5):737-742
Symbiotic dinoflagellates of the species Amphidinium are expected to be pharmaceutically useful microalgae because they produce antitumor macrolides. A microalgae production
system with a large number of cells at a high density has been developed for the efficient production of macrolide compounds.
In the present study, the effects of culture conditions on the cellular growth rate of dinoflagellates were investigated to
determine the optimum culture conditions for obtaining high yields of microalgae. Amphidinium species was cultured under conditions with six temperature levels (21–35°C), six levels of photosynthetic photon flux density
(15–70 μmol photons m−2 s−1), three levels of CO2 concentration (0.02–0.1%), and three levels of O2 concentration (0.2–21%). The number of cells cultured in a certain volume of solution was monitored microscopically and the
cellular growth rate was expressed as the specific growth rate. The maximum specific growth rate was 0.022 h−1 at a temperature of 26°C and O2 concentration of 5%, and the specific growth rate was saturated at a CO2 concentration of 0.05%, a photosynthetic photon flux density of 35 μmol photons m−2 s−1 and a photoperiod of 12 h day−1 upon increasing each environmental parameter. The results demonstrate that Amphidinium species can multiply efficiently under conditions of relatively low light intensity and low O2 concentration. 相似文献
8.
Although resistance of microorganisms to Hg(II) salts has been widely investigated and resistant strains have been reported
from many eubacterial genera, there are few reports of mercuric ion resistance in extremophilic microorganisms. Moderately
thermophilic mercury resistant bacteria were selected by growth at 62 °C on Luria agar containing HgCl2. Sequence analysis of 16S rRNA genes of two isolates showed the closest matches to be with Bacillus pallidus and Ureibacillus thermosphaericus. Minimum inhibitory concentration (MIC) values for HgCl2 were 80 μg/ml and 30 μg/ml for these isolates, respectively, compared to 10 μg/ml for B. pallidus H12 DSM3670, a mercury-sensitive control. The best-characterised mercury-resistant Bacillus strain, B. cereus RC607, had an MIC of 60 μg/ml. The new isolates had negligible mercuric reductase activity but removed Hg from the medium
by the formation of a black precipitate, identified as HgS by X-ray powder diffraction analysis. No volatile H2S was detected in the headspace of cultures in the absence or presence of Hg2+, and it is suggested that a new mechanism of Hg tolerance, based on the production of non-volatile thiol species, may have
potential for decontamination of solutions containing Hg2+ without production of toxic volatile H2S. 相似文献
9.
We evaluated the combined effects of algal (Chlorella vulgaris) food levels (low, 0.5 × 106 (or 2.9 μg C ml−1); and high, 1 × 106 cells ml−1 (or 5.8 μg C ml−1)) and zinc concentrations (0, 0.125, and 0.250 mg l−1 of ZnCl2) on the competition between two common planktonic rotifers Anuraeopsis fissa and Brachionus rubens using their population growth. Median lethal concentration data (LC50) (mean ± 95% confidence intervals) showed that B. rubens was more resistant to zinc (0.554 ± 0.08 mg l−1) than A. fissa (0.315 ± 0.07 mg l−1). A. fissa when grown alone or with Zn was always numerically more abundant than B. rubens. When grown in the absence of zinc, under low- and high-food levels, the peak abundances of A. fissa varied from 251 ± 24 to 661 ± 77 ind. ml−1, respectively, and the corresponding maxima for B. rubens were 52 ± 3 and 102 ± 18 ind. ml−1. At a given food level, competition for food reduced the peak abundances of both rotifers considerably. Increase in Zn concentration
also lowered the rotifer abundances. The impact of zinc on competition between the two-rotifer species was evident at low-food
level, mainly for A. fissa. At zinc concentrations of 0 and 0.125 mg l−1, the populations of both rotifers continued to grow for about 10 days, but thereafter B. rubens began to decline. Role of zinc on the competitive outcome of the two species is discussed in relation to the changing algal
densities in natural water bodies. 相似文献
10.
Oyamada H Ogawa Y Shibata N Okawa Y Suzuki S Kobayashi H 《Archives of microbiology》2008,189(5):483-490
We investigated the structural and immunochemical characteristics of cell wall mannan obtained from Candida sojae JCM 1644, which is a new yeast species isolated from defatted soybean flakes. The results of a slide-agglutination test and
of an enzyme-linked immunosorbent assay using anti-factor sera to the pathogenic Candida species indicated that the cells and the C. sojae mannan were cross-reactive to the specific anti-factor sera against Candida albicans serotype A (FAb 6) and Candida guilliermondii (FAb 9). Two-dimensional homonuclear Hartmann–Hahn analysis indicated that the mannan consisted of various linked oligomannosyl
side chains containing α-1,2-, α-1,3-, α-1,6- and β-1,2-linked mannose residues. However, although the determinants of antigenic
factors 6 and 9 could be not found in this mannan, branched side chains, Manβ1-2Manα1-3[Manα1-6]Manα1-(2Manα1-)n2Man and a
linear α-1,6-linked polymannosyl backbone, which are cross-reacted by FAbs 6 and 9, respectively, were identified. The mannan
was subjected to acetolysis in order to determine the polymerization length of the α-1,2-linked oligomannosyl residue in the
side chains. The result of 1H-nuclear magnetic resonance analysis of the released oligosaccharides showed that the remarkable regularity in the length
of α-1,2-linked oligomannosyl side chains, which were previously found in mannans of other Candida species, is not observed in this mannan. 相似文献
11.
Acetylene reduction and indoleacetic acid production by Azospirillum isolates from Cactaceous plants
Azospirillum isolates were obtained from rhizosphere soil and roots of three cactaceae species growing under arid conditions.
All Azospirillum isolates from rhizosphere and roots ofStenocereus pruinosus andStenocereus stellatus were identified asA. brasilense; isolates of surface-sterilized roots fromOpuntia ficus-indica were bothA. brasilense andA. lipoferum. Azospirilla per g of fresh root in the three species ranged from 70×103 to 11×103. The most active strains in terms of C2H2 reduction (25–49.6 nmol/h·ml) and indoleacetic acid (IAA) production (36.5–77 μg/ml) were those identified asA. brasilense and isolated from Stenocereus roots.A. lipoferum isolated from Opuntia roots produced low amounts of IAA (6.5–17.5 μg/ml) and low C2H2-reduction activity (17.8–21.2 nmol/h·ml). 相似文献
12.
Information on gonad morphology and its relation to basic reproductive parameters such as clutch size and spawning frequency
is lacking for Acartia clausi, a dominant calanoid copepod of the North Sea. To fill this gap, females of this species were sampled at Helgoland Roads
from mid March to late May 2001. Gonad structure and oogenesis were studied using a combination of histology and whole-body-analysis.
In addition, clutch size and spawning frequency were determined in incubation experiments, during which individual females
were monitored at short intervals for 8 and 12 h, respectively. The histological analysis revealed that the ovary of A. clausi is w-shaped with two distinct tips pointing posteriorly. It is slightly different from that of other Acartia species and of other copepod taxa. From the ovary, two anterior diverticula extend into the head region, and two posterior
diverticula extend to the genital opening in the abdomen. Developing oocytes change in shape and size, and in the appearance
of the nucleus and the ooplasm. Based on these morphological characteristics, different oocyte development stages (OS) were
identified. Mitotically dividing oogonia and young oocytes (OS 0) were restricted to the ovary, whereas vitellogenic oocytes
(OS 1–4) were present in the diverticula. The development stage of the oocytes increased with distance to the ovary in both,
anterior and posterior diverticula. Most advanced oocytes were situated ventrally, and their number varied between 1 and 18,
at a median of 4. All oocyte development stages co-occur indicating that oogenesis in A. clausi is a continuous process. These morphological features reflect the reproductive traits of this species. In accordance with
the low numbers of mature oocytes in the gonads, females usually produced small clutches of one to five eggs. Clutches were
released throughout the entire observation period at intervals of 90 min (median) resulting in mean egg production rates of
18–28 eggs female−1 day−1. 相似文献
13.
Siphonophores are exclusively marine cnidaria and their predatory role in plankton food-webs is well recognised. In this study,
we analyse the structure and the spatial extent of siphonophore assemblages in relation to changes in freshwater outflows
and food availability in the southern Gulf of Mexico during a high (October) and a low (April) outflow periods. A total of
149 samples were collected using a 505 μm multiple closing net at 1–6 levels (0–100 m) of the water column, depending on the
bathymetry. Data on siphonophore species biovolumes (ml 100 m−3) were treated by means of the Bray-Curtis Dissimilarity Index, and two distinctive assemblages were identified: the ‘inner’
and the ‘outer’ assemblages, located over the inner and outer shelves. Temperature, salinity, zooplankton biomass, and siphonophore
species were included in a Principal Component Analysis (PCA) to identify the factors associated with each assemblage. Geographical
distribution of the assemblages practically remained the same during both seasons and its cross-shelf variability was stronger
than the vertical one. Seasonally, diversity values were higher in October, when the highest river discharges occur. Spatially,
the lowest diversity and mean siphonophore biovolumes values were registered in the ‘inner assemblage’, where the highest
and lowest salinity values were recorded. We suggest that even when extreme salinity values (>36.5 or <34) might depress siphonophore
populations in the coastal area, enough food availability in the concerned areas might mitigate the negative effect of salinity,
since a positive and significant (p < 0.05) relationship was found between siphonophores biovolume and zooplankton biomass. Bassia bassensis, Diphyes dispar and Enneanogum hyalinum, present in both assemblages during both seasons, were able to survive in a wide range of salinity values, following perhaps,
their prey. All the 23 species here registered were found in the ‘outer assemblage’; however, Abylopsis eschscholtzi, Chelophyes appendiculata and Diphyes bojani were more associated with the ‘outer’ group according to the PCA results. Enneagonum hyalinum was the only species frequently encountered and abundant in the ‘inner assemblage’ during both seasons and, supporting previous
observations, this species might be considered as an indicator of nearshore waters.
Handling editor: K. Martens 相似文献
14.
Two new effective microbial producers of inulinases were isolated from Jerusalem artichoke tubers grown in Thailand and identified
as Aspergillus niger TISTR 3570 and Candida
guilliermondii TISTR 5844. The inulinases produced by both these microorganisms were appropriate for hydrolysing inulin to fructose as the
principal product. An initial inulin concentration of ∼100 g l−1 and the enzyme concentration of 0.2 U g−1 of substrate, yielded 37.5 g l−1 of fructose in 20 h at 40°C when A. niger TISTR 3570 inulinase was the biocatalyst. The yield of fructose on inulin was 0.39 g g−1. Under identical conditions, the yeast inulinase afforded 35.3 g l−1 of fructose in 25 h. The fructose yield was 0.35 g g−1 of substrate. The fructose productivities were 1.9 g l−1 h−1 and 1.4 g l−1 h−1 for the mold and yeast enzymes, respectively. After 20 h of reaction, the mold enzyme hydrolysate contained 53% fructose
and more than 41% of initial inulin had been hydrolysed. Using the yeast enzymes, the hydrolysate contained nearly 38% fructose
at 25 h and nearly 36% of initial inulin had been hydrolysed. The A. niger TISTR 3570 inulinases exhibited both endo-inulinase and exo-inulinase activities. In contrast, the yeast inulinases displayed
mainly exo-inulinase activity. The mold and yeast crude inulinases mixed in the activity ratio of 5:1 proved superior to individual
crude inulinases in hydrolysing inulin to fructose. The enzyme mixture provided a better combination of endo- and exo-inulinase
activities than did the crude extracts of either the mold or the yeast individually. 相似文献
15.
Angela Breeuwer Monique M. P. D. Heijmans Maurits Gleichman Bjorn J. M. Robroek Frank Berendse 《Plant Ecology》2009,204(1):97-111
To predict the role of ombrotrophic bogs as carbon sinks in the future, it is crucial to understand how Sphagnum vegetation in bogs will respond to global change. We performed a greenhouse experiment to study the effects of two temperature
treatments (17.5 and 21.7°C) and two N addition treatments (0 and 4 g N m−2 year−1) on the growth of four Sphagnum species from three geographically interspersed regions: S. fuscum, S. balticum (northern and central Sweden), S. magellanicum and S. cuspidatum (southern Sweden). We studied the growth and cover change in four combinations of these Sphagnum species during two growing seasons. Sphagnum height increment and production were affected negatively by high temperature and high N addition. However, the northern species
were more affected by temperature, while the southern species were more affected by N addition. High temperature depressed
the cover of the ‘wet’ species, S. balticum and S. cuspidatum. Nitrogen concentrations increased with high N addition. N:P and N:K ratios indicated P-limited growth in all treatments
and co-limitation of P and K in the high N treatments. In the second year of the experiment, several containers suffered from
a severe fungal infection, particularly affecting the ‘wet’ species and the high N treatment. Our findings suggest that global
change can have negative consequences for the production of Sphagnum species in bogs, with important implications for the carbon sequestration in these ecosystems. 相似文献
16.
An endophytic Xylaria sp., having broad antimicrobial activity, was isolated and characterized from Ginkgo biloba L. From the culture extracts of this fungus, a bioactive compound P3 was isolated by bioactivity-guided fractionation and
identified as 7-amino-4-methylcoumarin by nuclear magnetic resonance, infrared, and mass spectrometry spectral data. The compound
showed strong antibacterial and antifungal activities in vitro against Staphylococcus aureus [minimal inhibitory concentrations (MIC) 16 μg·ml−1], Escherichia coli (MIC, 10 μg·ml−1), Salmonella typhia (MIC, 20 μg·ml−1), Salmonella typhimurium (MIC, 15 μg·ml−1), Salmonella enteritidis (MIC, 8.5 μg·ml−1), Aeromonas hydrophila (MIC, 4 μg·ml−1), Yersinia sp. (MIC, 12.5 μg·ml−1), Vibrio anguillarum (MIC, 25 μg·ml−1), Shigella sp. (MIC, 6.3 μg·ml−1), Vibrio parahaemolyticus (MIC, 12.5 μg·ml−1), Candida albicans (MIC, 15 μg·ml−1), Penicillium expansum (MIC, 40 μg·ml−1), and Aspergillus niger (MIC, 25 μg·ml−1). This is the first report of 7-amino-4-methylcoumarin in fungus and of the antimicrobial activity of this metabolite. The
obtained results provide promising baseline information for the potential use of this unusual endophytic fungus and its components
in the control of food spoilage and food-borne diseases. 相似文献
17.
The cyanobacterial species composition of nine Greek waterbodies of different type and trophic status was examined during
the warm period of the year (May–October). Cyanobacterial water blooms were observed in all waterbodies. Forty-six cyanobacterial
taxa were identified, 11 of which are known to be toxic. Eighteen species are reported for the first time in these waterbodies,
8 of which are known to produce toxins. Toxin producing species were found in all of the waterbodies and were primarily dominant
in bloom formations (e.g., Microcystis aeruginosa, Anabaena flos-aquae, Aphanizomenon flos-aquae and Cylindrospermopsis raciborskii). Cosmopolitan species (e.g., M. aeruginosa), pantropic (e.g., Anabaenopsis tanganyikae) and holarctic species (e.g., Anabaena flos-aquae) were encountered. Shallow, eutrophic waterbodies had blooms dominated by Microcystis species and were characterized by phytoplankton association M. Anabaena and Aphanizomenon species of association H were dominant in waterbodies with low dissolved inorganic nitrogen and thermal stratification in
the summer. Total cyanobacterial biovolumes (CBV) ranged from 7 to 9,507 cm3 m−3 and were higher than Alert Level 2 and Guidance Level 2 (10 cm3 m−3; World Health Organization; WHO) in seven of the waterbodies. Chlorophyll a concentrations ranged from 6 to 90,000 mg m−3 and were higher than Alert Level 2 and Guidance Level 2 (50 mg m−3; WHO) in eight of the waterbodies. There is also an elevated risk of acute toxicosis (Guidance Level 3; WHO) in five waterbodies.
Water of an undesirable quality, hazardous to humans and animals occurs in several Greek waterbodies. 相似文献
18.
Oswaldo Guzmán-López Ángel Trigos Francisco J. Fernández María de Jesús Yañez-Morales Gerardo Saucedo-Castañeda 《World journal of microbiology & biotechnology》2007,23(10):1473-1477
Extracellular tyrosol and tryptophol were produced and isolated from the phytopathogen fungus Ceratocystis adiposa cultivated in a rich broth. These compounds have not been previously reported in this Ceratocystis species, as its identification was established through spectroscopic methods (1H NMR, 13C NMR and MS). Productivity of tyrosol and tryptophol was 65.3 and 44 μg l−1 day−1, respectively, which were values higher than those reported to date. Tyrosol is a compound of pharmaceutical interest showing
antioxidating activity, a property used in the treatment of atherosclerosis. Tryptophol is reported to have antibiotic and
phytotoxic activity. 相似文献
19.
In the wild type strain (stock no. 1227) of Thermoactinomyces vulgaris, as reported earlier [Sinha and Singh (1980) Biochem. J. 190, 457–460], all phosphatase isoenzymes (three alkaline — AlpI,
AlpII and AlpIII, and one acidic — Acp) are present. However, the auxotrophic mutants, the strains 1286 (thi
−), 1279 (nic
−, ura
−) and 1278 (thi
−, ura
−) exhibited two alkaline phosphatase isoenzymes (AlpII and AlpIII), but AlpI was lacking. In the strain 1261 (nic
−, thi
−), only AlpIII was expressed, and AlpI and AlpII isoenzymes were missing. The results suggest that the strains, which require
either thiamine (1286 and 1278) or nicotinamide (1279) for their growth, were AlpI
− mutants; and the strain (1261), which requires both thiamine and nicotinamide for its growth, was AlpI
−/AlpII
− double mutant. There was no direct correlation between uracil auxotrophy and the expression of phosphatases. The uniform
expression of AlpIII and Acp in all the strains, irrespective of their nutrient requirements, suggest that these constitutive
phosphatases are species-specific. The specific activities of the thermophilic acid and alkaline phosphatases were maximum
in the wild type strain (1227) of T. vulgaris. The next in phosphatase activity was the strain 1279 (an AlpI
− mutant), followed by their decrease, in order, in the strains 1286 and 1278 (which were also AlpI
− mutants); while least activity of these enzymes was observed in the obligate thermophile strain 1261 (AlpI
−/AlpII
− double mutant). 相似文献
20.
Da-Chun Zhuang Yi-Guang Chen Yu-Qin Zhang Shu-Kun Tang Xiao-Lei Wu Zhou-Cai Tan Wen-Jun Li Xiao-Long Cui 《Antonie van Leeuwenhoek》2009,96(3):295-301
A novel Gram-negative, catalase- and oxidase-positive, non-sporulating, rod-shaped, aerobic bacterium, designated strain JSM
078120T, was isolated from sea water collected from a tidal flat of Naozhou Island, South China Sea. Growth occurred with 1–15% (w/v)
total salts (optimum, 2–4%), at pH 6.0–10.0 (optimum, pH 7.5) and at 4–35°C (optimum, 25–30°C). The major cellular fatty acids
were C18:1
ω9c, C16:0, C12:0 3-OH and C16:1
ω7c. The predominant respiratory quinone was ubiquinone Q-9, and the genomic DNA G + C content was 60.6 mol%. Phylogenetic analysis
based on 16S rRNA gene sequences indicated that strain JSM 078120T should be assigned to the genus Marinobacter, being related most closely to the type strains of Marinobacter segnicrescens (sequence similarity 98.2%), Marinobacter bryozoorum (97.9%) and Marinobacter gudaonensis (97.6%). The sequence similarities between the novel isolate and the type strains of other recognized Marinobacter species ranged from 96.7 (with Marinobacter salsuginis) to 93.3% (with Marinobacter litoralis). The levels of DNA–DNA relatedness between strain JSM 078120T and the type strains of M. segnicrescens, M. bryozoorum and M. gudaonensis were 25.3, 20.6 and 18.8%, respectively. The combination of phylogenetic analysis, DNA–DNA relatedness, phenotypic characteristics
and chemotaxonomic data supported the view that strain JSM 078120T represents a novel species of the genus Marinobacter, for which the name Marinobacter zhanjiangensis sp. nov. is proposed. The type strain is JSM 078120T (= CCTCC AB 208029T = DSM 21077T = KCTC 22280T).
The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JSM 078120T is FJ425903. 相似文献