Spore germination in the Psilotaceae

1994 ◽  
Vol 72 (5) ◽  
pp. 688-692 ◽  
Author(s):  
Dean P. Whittier ◽  
John E. Braggins
Keyword(s):  
Key Words ◽  
Nitrogen Source ◽  
Spore Germination ◽  
Nutrient Medium

Spores of several species of Psilotum and Tmesipteris were sown on a nutrient medium containing minerals and 0.2% glucose. The nutrient medium contained ammonium as the nitrogen source and lacked nitrate. From 52 to 98% of the spores of P. nudum, P. complanatum, T. lanceolata, and T. sigmatifolia germinated after 6 months in the dark. Haploid spores of P. nudum began germinating in less than 2 months; however spores of the two Tmesipteris species reached 50% germination sooner than those of the Psilotum species. Spores of T. tannensis never germinated and those of T. elongata and P. × intermedium rarely germinated (<0.1%) and never formed mature gametophytes. Spores from only one species, T. lanceolata, occasionally germinated in the light, but gametophytic development never proceeded beyond the two-celled stage. Spores of T. lanceolata and T. sigmatifolia stored at −70 °C for 21 months germinated essentially as well as the fresh spores. The nutrient medium appears suitable for studies on gametophytes of the Psilotaceae because it promoted spore germination and gametophytic growth for most of the species tested. Key words: Psilotum, Tmesipteris, spore, germination.

scholarly journals Production characteristics of the diatom Cylindrotheca closterium (Ehrenb.) Reimann et Lewin grown in an intensive culture at various nitrogen sources in the medium

2019 ◽  
Vol 4 (1) ◽  
pp. 33-44 ◽  
Author(s):  
S. N. Zheleznova
Keyword(s):  
Stationary Phase ◽  
Nitrogen Source ◽  
Nutrient Medium ◽  
Maximum Yield ◽  
Nitrogen Sources ◽  
Dry Weight ◽  
Sole Source ◽  
Active Growth ◽  
Cylindrotheca Closterium ◽  
Production Characteristics

The diatom Cylindrotheca closterium (Ehrenberg) Reimann et Levin is characterized by high productivity (up to 1.5 g·l-1·day-1) and the ability to accumulate a valuable carotenoid fucoxanthin (up to 2 % of dry weight). In the development of biotechnology based on microalgae, the key issue is the creation of concentrated nutrient medium. Nitrogen is one of the most important components in the nutrient medium that significantly affects the production characteristics of all microalgae. The aim of this study is to compare the production characteristics of C. closterium in an intensive storage culture using different forms of nitrogen in the medium. In the first experiment, nitrate and sodium nitrite, urea, and nitrogen in the form of ammonium were used as a source of nitrogen. The amount of nitrates, nitrites, ammonium, and urea in the medium was calculated from the nitrogen content of the RS nutrient medium, with a nitrogen to phosphorus ratio of 15 : 1. In the second experiment, amino acids were used as a nitrogen source – arginine, asparagine, cysteine. The possibility of using the microalgae C. closterium for the growth of various organic sources of nitrogen (urea, cysteine, asparagine) was shown. Productive characteristics in the intensive storage culture of C. closterium using urea, cysteine, and asparagine as the sole source of nitrogen in the RS nutrient medium were determined. It is shown that when urea was used, the productivity reached its maximum values and amounted to 1.5 g·l-1·day-1. Thus, the expediency of using urea in the medium for obtaining the maximum yield of biomass was shown. The use of cysteine in the stationary phase of growth to achieve a long stationary phase with minimal concentrations of the nitrogen source in the nutrient medium is also advisable. It was found that C. closterium was able to grow and vegetate at sufficiently high concentrations of nitrite, and the addition of nitrogen in ammonium form to the nutrient medium during the active growth of C. closterium led to inhibition of all metabolic processes and to the death of the culture.

The role of fosetyl-Al in the potential integrated control of Fulvia fulva

1991 ◽  
Vol 69 (2) ◽  
pp. 306-310 ◽  
Author(s):  
Yves Tirilly
Keyword(s):  
Key Words ◽  
Spore Germination ◽  
Integrated Control ◽  
Integrated System ◽  
Lesion Formation ◽  
Destructive Action ◽  
Fulvia Fulva ◽  
Minimal Concentration

Fulvia fulva, the agent of leaf mould, is known to be a major parasite of tomato leaves in greenhouses. Its development is characterized by a biotrophic phase followed by a necrotrophic phase. Hansfordia pulvinata is a hyperparasite of this pathogen, but its destructive action is restricted by its inability to colonize F. fulva during the biotrophic phase, before lesion formation. An integrated system to optimize the mycoparasitic activity of H. pulvinata was studied. The hyperparasite was tolerant to fosetyl-Al in situ. At a minimal concentration of 500 mg/L, the fungicide inhibited F. fulva spore germination after spraying on tomato leaves but did not have any effect during the necrotrophic phase. Thus, fosetyl-Al, which prevented reinfection, and the destructive hyperparasite H. pulvinata had complementary effects. Key words: Hansfordia pulvinata, fosetyl-Al, Fulvia fulva, integrated control, leaf mould, tomato.

scholarly journals The effect of diverse nitrogen sources in the nutrient medium on the growth of the green microalgae Chromochloris zofingiensis in the batch culture

2019 ◽  
Vol 4 (4) ◽  
pp. 41-52 ◽  
Author(s):  
G. S. Minyuk ◽  
N. V. Dantsyuk ◽  
E. S. Chelebieva ◽  
I. N. Chubchikova ◽  
I. V. Drobetskaya ◽  
...  
Keyword(s):  
Nitrogen Source ◽  
Nutrient Medium ◽  
Nitrogen Sources ◽  
Dry Weight ◽  
Cell Swelling ◽  
Total Carotenoids ◽  
Chlorella Zofingiensis ◽  
N Sources ◽  
N Source ◽  
Chlorophylls A And B

The effect of three nitrogen (N) sources in the nutrient medium – sodium nitrate (NaNO3), urea (CO(NH2)2), and ammonium chloride (NH4Cl) – on the morphological and physiological characteristics of the green microalga Chromochloris (Chlorella) zofingiensis, a potential commercial producer of lipids and a ketocarotenoid astaxanthin, was studied. The alga was batch-cultivated in glass conical flasks from starting cell density (n) around 2.3·106 per mL and dry weight (DW) content of 0.06 g·L−1 in all variants at 120 μmol·m−2·s−1 PAR, +20…+21 °C, and air bubbling at a rate of 0.3 L·min−1·L−1. The concentration of nitrogen sources (as elemental N) in the modified BBM nutrient medium was 8.83 mmol·L−1, the cultivation duration was 17 days. The dynamics of n and cell volumes, DW content, chlorophylls a and b (Chla and Chlb), total carotenoids (Car), and lipids (Lip) in the cultures, concentration of N sources in the nutrient medium, and its pH were recorded. It was shown that the growth rate, size distribution of the cell populations, and the biomass chemical composition depended significantly on the nitrogen source in the nutrient medium. Using NH4Cl as N source caused on the second day growth inhibition, cell swelling, aggregation, and discoloration; by the seventh day, it caused culture crash. C. zofingiensis cells took up NaNO3 and CO(NH2)2 from the medium at a similar rate (0.626 and 0.631 mmol N·L−1·day−1, respectively), but the growth of the culture fed with CO(NH2)2 lagged; its cell volume and Chla, Chlb, and total Car contents declined profoundly. The average dry matter productivity (PDW) in the culture grown on CO(NH2)2 [(0.086 ± 0.004) g·L−1·day−1] was 32.6 % lower than in the culture grown on NaNO3 [(0.114 ± 0.005) g·L−1·day−1]. At the same time, lipid productivity (PLip) of the urea-fed culture was comparable with that of the nitrate-fed culture (PLip of 28 and 26 mg·L−1·day−1, respectively). The lipid DW percentage of the former exceeded significantly that of the nitrate-fed culture (31.6 % vs 23.1 %, respectively). From the standpoint of profitability, the lag in biomass accumulation recorded in the urea-fed culture on PDW is not critical since it is compensated by lowering the cost of nitrogen source for the nutrient medium (approximately by 230 %) and a higher biomass lipid content. C. zofingiensis grown in media with urea as the only N source deserves further investigation.

Effect of Ammonium Sulphate on the Sporulation of Bacillus thuringiensis subsp. aizawai SN2 (a Local Isolate) during Batch Fermentation

2012 ◽  
Author(s):  
Wan Mohtar Wan Yusoff ◽  
Mohd. Mazmira Mohd. Masri ◽  
Choy Mei Chan
Keyword(s):  
Bacillus Thuringiensis ◽  
Nitrogen Content ◽  
Key Words ◽  
Nitrogen Source ◽  
Ammonium Sulphate ◽  
Batch Fermentation ◽  
Inorganic Nitrogen ◽  
Inorganic Nitrogen Source ◽  
Initial Concentration ◽  
Bacillus Thuringiensis Subsp

Kesan penambahan ammonium sulfat, (NH4)2SO, (sebagai sumber nitrogen bukan organik tunggal) terhadap pensporaan Bacillus thuringiensis subsp. aizawai strain SN2 dalam kultur kelompok telah dikaji. Peratus spora tertinggi (76 %) dikesan selepas 96 j pengkulturan dalam medium yang mengandungi 1.5 gL-1 (NH4)2SO4. Peratus spora tertinggi sebanyak 82 % juga dikesan dalam sampel 96 j apabila medium yang mengandungi 1.5 gL-1 (NH4)2SO4 ditambah dengan 3.0 gL-1 (NH4)2SO4 pada jam keenam selepas mula fermentasi. Peningkatan peratus spora didapati tidak berkaitan dengan jumlah kandungan nitrogen tetapi berkaitan dengan masa penambahan sumber nitrogen. Kata kunci: Bacillus thuringiensis subsp. aizawai strain SN2, masa penambahan nutrien, kultur kelompok The effect of ammonium sulphate (as the sole inorganic nitrogen source) on the sporulation of Bacillus thuringiensis subsp. aizawai strain SN2 was investigated in batch fermentation. The spore percentage of 76 % was achieved at 96 h after inoculation into a medium containing initial cencentration of 1.5 gL-1 ammonium sulphate. In another experiment, the maximum spore percentage of 82 % was obtained after 96 h inoculation in a medium with initial concentration of 1.5 gL-1 (NH4)2SO4 followed by an addition of 3.0 gL-1 (NH4)2SO4 after 6 h of fermentation. The increase in Bacillus thuringiensis spore percentage was not a function of total nitrogen content in the medium but was a function of the time nitrogen being added. Key words: Bacillus thuringiensis subsp. aizawai strain SN2, timing addition, batch fermentation

Effect of Red Extractives of Plantation Leaves on Bamboo Biomass Mildewing

2011 ◽  
Vol 704-705 ◽  
pp. 419-423
Author(s):  
Feng Juan Wu ◽  
Wan Xi Peng ◽  
Dao Chun Qin ◽  
Fang Lu
Keyword(s):  
Key Words ◽  
Pinus Taeda ◽  
Spore Germination ◽  
Eucalyptus Grandis ◽  
Value Added ◽  
Santalum Album ◽  
Tree Leaves ◽  
Osmanthus Fragrans ◽  
Eucalyptus Dunnii ◽  
Outdoor Test

Bamboo is so easy to get mildewed that bamboo products are still low value added. Therefore, the effect of red extractives from 28 tree leaves on bamboo biology mildewing was studied basing on full-factor test. The result was as follows: (1) most red extractives of tree leaves can inhibit the growth of P. expansum, but a few can inhibit the growth of A. alternate; (2) The red extractives from tree leaves of Deodar cedar, Eucalyptus grandis, Eucalyptus dunnii and pear were the most effective to control spore germination of P. expansum, and those of Manglietia glauca, Osmanthus fragrans, and Melia toosendanin were the most effective to control spore germination of A. alternata; (3) The effect of the red extractives from Pinus taeda, Eucalyptus grandis and Santalum album on bamboo biomass mildewing was highly remarkable on mildew-proof by outdoor test. Our result pointed out the direction for the development of the biological mildew inhibitor from tree leaves. Key words. tree leaves, bamboo biomass, benzene/alcohol extractives

The effect of light and other factors on spore germination in Botrychium dissectum

1973 ◽  
Vol 51 (10) ◽  
pp. 1791-1794 ◽  
Author(s):  
Dean P. Whittier
Keyword(s):  
Spore Germination ◽  
Nutrient Medium ◽  
Axenic Culture ◽  
Effect Of Light

Light-inhibited spore germination in Botrychium dissectum forma obliquum occurred in axenic culture on a nutrient medium containing 0.25% sucrose. The spores had to be cultured in darkness for 3–4 weeks before any germination would take place. Longer periods in the dark produced greater percentages of germination. Sucrose was unnecessary for germination, but it promoted gametophytic growth once germination had occurred.

Urea metabolism and urease regulation in the cyanobacterium Anabaena variabilis

1990 ◽  
Vol 36 (3) ◽  
pp. 218-222 ◽  
Author(s):  
Xin Ge ◽  
Karen Cain ◽  
Rona Hirschberg
Keyword(s):  
Key Words ◽  
Nitrogen Source ◽  
Anabaena Variabilis ◽  
Acetohydroxamic Acid ◽  
Transcription Level ◽  
Heat Resistant ◽  
Cyanobacterium Anabaena ◽  
Urea Metabolism

Anabaena variabilis can use urea as a nitrogen source, which it breaks down via the action of urease. No evidence of urea amidolyase activity was found. Urease synthesis is constitutive; no major difference in enzyme levels was found when cultures were grown with urea, ammonia, or N2. Urea is not required for urease synthesis, and ammonia does not repress urease synthesis. However, urea does repress nitrogenase synthesis at the transcription level, probably by the same mechanism as ammonia. Anabaena variabilis urease is inhibited by phenylphosphorodiamidate, hydroxyurea, and acetohydroxamic acid, which suggests that the enzyme contains nickel. A Km for urea of 46 μM was observed in crude cell free extracts. The enzyme is cytoplasmic and relatively heat resistant. Key words: urea, urease, cyanobacteria, Anabaena variabilis.

METABOLISM OF 14C- AND 15N-LABELLED ACETAMIDE AND ACETYLUREA AS NPN SOURCES

1984 ◽  
Vol 64 (5) ◽  
pp. 37-38 ◽  
Author(s):  
H. BERGNER
Keyword(s):  
Protein Synthesis ◽  
Key Words ◽  
Nitrogen Source ◽  
Bacterial Protein ◽  
Hepatic Circulation ◽  
High Level ◽  
Bacterial Protein Synthesis

Acetamide was degraded in the rumen and was used for bacterial protein synthesis on a high level. Acetylurea was not degraded in the rumen. 15N-labelled urea returned via rumino-hepatic circulation to the rumen after the degradation of acetylurea outside the rumen and served as a nitrogen source for bacterial protein synthesis. Key words: 14C-15N-acetamide, 14C-15N-acetylurea, NPN, bacterial protein, sheep

The role of extracellular polysaccharide in cell viability and nitrogenase activity of Beijerinckia derxii

1992 ◽  
Vol 38 (9) ◽  
pp. 986-988 ◽  
Author(s):  
H. R. Barbosa ◽  
F. Alterthum
Keyword(s):  
Cell Viability ◽  
Key Words ◽  
Nitrogen Source ◽  
Saline Solution ◽  
Nitrogenase Activity ◽  
High Sensitivity ◽  
Extracellular Polysaccharide ◽  
Polysaccharide Layer ◽  
Adequate Method

Cells of Beijerinckia derxii grown on NH4+ or N2 as the nitrogen source were treated to remove their extracellular polysaccharide layer without loss of viability. An adequate method for extracellular polysaccharide extraction was established. After extracellular polysaccharide removal N2-grown cells showed reduced nitrogenase activity, and when stirred for 90 min at 200 rpm, suffered a total loss of viability. In contrast, NH4+-grown cells were not affected when submitted to the same conditions. However, these cells showed a high sensitivity to saline solution. Key words: extracellular polysaccharide, nitrogenase, Beijerinckia derxii, exopolysaccharide.

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