The potential for N(2) fixation by heterocystous cyanobacteria isolated from soils of different geographical areas was determined as nitrogenase activity (NA) using the acetylene reduction assay. Morphology of cyanobacteria had the largest influence on NA determined under light conditions. NA was generally higher in species lacking thick slime sheaths. The highest value (1446 nmol/h C(2)H(4) per g fresh biomass) was found in the strain of branched cyanobacterium Hassalia (A Has1) from the polar region. A quadratic relationship between NA and biomass was detected in the Tolypothrix group under light conditions. The decline of NA in dark relative to light conditions ranged from 37 to 100 % and differed among strains from distinct geographical areas. Unlike the NA of temperate and tropical strains, whose decline in dark relative to light was 24 and 17 %, respectively, the NA of polar strains declined to 1 % in the dark. This difference was explained by adaptation to different light conditions in temperate, tropical, and polar habitats. NA was not related to the frequency of heterocysts in strains of the colony-forming cyanobacterium Nostoc. Colony morphology and life cycle are therefore more important for NA then heterocyst frequency. NA values probably reflect the environmental conditions where the cyanobacterium was isolated and the physiological and morphological state of the strain.

• MeSH
• acetylen metabolismus   MeSH
• fixace dusíku * MeSH
• nitrogenasa metabolismus   MeSH
• půdní mikrobiologie * MeSH
• sinice klasifikace   enzymologie   fyziologie   MeSH
• studené klima MeSH
• světlo * MeSH
• tma MeSH
• tropické klima MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylen MeSH
• nitrogenasa MeSH

This paper provides a comprehensive overview of metabolites, including lipids and lipid-like compounds, nitrogen metabolites, oligopeptides and amino acid derivatives, produced by cyanobacteria of the genera Anabaenopsis, Aphanizomenon, Aulosira, Cylindrospermopsis, Cylindrospermum, Nodularia, and Richelia of the family Nostocaceae.

• MeSH
• aminokyseliny metabolismus   MeSH
• bakteriální polysacharidy metabolismus   MeSH
• bakteriální toxiny metabolismus   MeSH
• hydroxykyseliny metabolismus   MeSH
• metabolismus lipidů MeSH
• Nostoc chemie   klasifikace   metabolismus   MeSH
• oligopeptidy metabolismus   MeSH
• sloučeniny dusíku metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• aminokyseliny MeSH
• bakteriální polysacharidy MeSH
• bakteriální toxiny MeSH
• hydroxykyseliny MeSH
• oligopeptidy MeSH
• sloučeniny dusíku MeSH

The influence of high light intensity on the growth and pigment accumulating ability of Anabaena azollae was investigated. A. azollae responded positively to high light intensity (6 klx) and was further evaluated at higher intensities (10 and 15 klx), in the presence of glucose, sucrose and jaggery +/- DCMU. Significant enhancement in phycobiliproteins and carotenoids was observed in the sugar supplemented cultures at high light intensities. SDS-PAGE profiles of whole cell proteins revealed the presence of unique bands in such treatments. Sucrose supplementation induced a 30-90 % increase in carotenoids, phycocyanin and phycoerythrin content at 10 klx. Molecular analysis of the stimulatory and interactive role of sugars on pigment enhancement at high light intensity may aid in better exploitation of cyanobacteria as a source of pigments.

• MeSH
• Anabaena chemie   růst a vývoj   metabolismus   účinky záření   MeSH
• bakteriální proteiny analýza   izolace a purifikace   MeSH
• biologické pigmenty analýza   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• fykocyanin analýza   MeSH
• fykoerythrin analýza   MeSH
• glukosa metabolismus   MeSH
• karotenoidy analýza   MeSH
• metabolismus sacharidů * MeSH
• proteom analýza   MeSH
• rostlinné extrakty metabolismus   MeSH
• Saccharum metabolismus   MeSH
• sacharosa metabolismus   MeSH
• světlo * MeSH
• světlosběrné proteinové komplexy analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• biologické pigmenty MeSH
• fykocyanin MeSH
• fykoerythrin MeSH
• glukosa MeSH
• Gur MeSH Prohlížeč
• karotenoidy MeSH
• proteom MeSH
• rostlinné extrakty MeSH
• sacharosa MeSH
• světlosběrné proteinové komplexy MeSH

Terrestrial blue-green algae Scytonema millei, Phormidium bohneri and Lyngbya mesotricha survived to 100 % at atmospheric temperatures of 5-36 degrees C and relative humidity 55-100 % in rainy, winter and spring seasons but the survival was 15-25 % in summer when atmospheric temperature reached 48 degrees C and relative humidity was < or =23 %. Microcoleus chthonoplastes maximum survival was =80 % in rainy season followed by a decrease to =1/2 and 1/4 level in winter and spring, respectively; it disappeared in summer but a few cells and/or trichomes enclosed within sheath may be surviving sticking to soil, not evident microscopically, since the population reappeared at the same place with the onset of rain. Terrestrial green alga Rhizoclonium crassipellitum survived only in spring and died at the onset of summer without forming any dormant cell and/or reproductive structure. Only P. bohneri survived better and longer under submerged conditions in liquid medium than air-exposed on moist soil surface in the culture chamber, while the other algae fared almost equally or slightly better air-exposed on moist soil surface (or even on 2 % agarized medium) than when suspended in liquid medium, indicating that air exposure rather than submerged conditions was needed for most of the terrestrial algae to survive. Water stress imposed on growing algae either on high-agar-solid media or in 0.2-0.6 mol/L NaCl liquid media in the culture chamber reduced vegetative survival in all; it resulted in death without any dormant cell remaining. When stored in desiccators over fused CaCl2, M. chthonoplastes died within 1/2 month, R. crassipellitum and L. mesotricha within 1 month, P. bohneri within 1/2 month, and S. millei not even within 1 1/2 month, indicating their survival pattern against atmospheric dryness to be wide; it also explained the M. chthonoplastes absence in summer and S. millei presence throughout the year. At increased atmospheric humidity the desiccation-sensitive algae (e.g., M. chthonoplastes) survived better than a desiccation-resistant alga (here S. millei). All algae survived considerable darkness (S. millei > 1 1/2 month; P. bohneri, M. chthonoplastes and R. crassipellitum >1 month, and L. mesotricha >1/2 month), and low light intensity of 2 and 10 micromol m(-2)s(-1) which explains their prolific growth in shady places. All algae were differently sensitive to wet heat (45 degrees C for 5-40 min) and to UV shock (0.96-3.84 kJ/m2).

• MeSH
• Chlorophyta fyziologie   účinky záření   MeSH
• ekosystém * MeSH
• hypertonický solný roztok MeSH
• roční období MeSH
• sinice fyziologie   účinky záření   MeSH
• teplota MeSH
• ultrafialové záření MeSH
• vlhkost MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hypertonický solný roztok MeSH