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.

Faculty of Science University of South Bohemia České Budějovice

Lit.: 39

000      

00000naa 2200000 a 4500

001      

bmc10032403

003      

CZ-PrNML

005      

20111210195701.0

008      

101118s2010 xr e eng||

009      

AR

040    __

$a ABA008 $b cze $c ABA008 $d ABA008 $e AACR2

041    0_

$a eng

044    __

$a xr

100    1_

$a Hrčková, Kristýna. $7 jcu2011661151

245    10

$a Biological dinitrogen fixation by selected soil cyanobacteria as affected by strain origin, morphotype, and light conditions / $c Hrčková K, Simek M, Hrouzek P, Lukešová A.

314    __

$a Faculty of Science, University of South Bohemia, České Budějovice

504    __

$a Lit.: 39

520    9_

$a 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.

650    _2

$a financování organizované $7 D005381

650    _2

$a acetylen $x metabolismus $7 D000114

650    _2

$a studené klima $7 D003081

650    _2

$a sinice $x enzymologie $x fyziologie $x klasifikace $7 D000458

650    _2

$a tma $7 D003624

650    _2

$a světlo $7 D008027

650    _2

$a fixace dusíku $7 D009586

650    _2

$a nitrogenasa $x metabolismus $7 D009591

650    _2

$a půdní mikrobiologie $7 D012988

650    _2

$a tropické klima $7 D014329

700    1_

$a Šimek, Miloslav, $d 1956- $7 jn20010309106

700    1_

$a Hrouzek, Pavel, $d 1981- $7 jcu2010578334

700    1_

$a Lukešová, Alena. $7 _AN031888

773    0_

$w MED00011005 $t Folia microbiologica $g Roč. 55, č. 5 (2010), s. 468-473 $x 0015-5632

910    __

$a ABA008 $b A 2403 $c 561 $y 6

990    __

$a 20101111142234 $b ABA008

991    __

$a 20110624094719 $b ABA008

999    __

$a ok $b bmc $g 820016 $s 685760

BAS    __

$a 3

BMC    __

$a 2010 $b 55 $c 5 $d 468-473 $m Folia microbiologica $x MED00011005

LZP    __

$a 2010-31/mkme