Diazotrophic cyanobacteria

Subramaniam, A., Carpenter, E. J., Karentz, D., and Falkowski, P. G., Bio-optical properties of the marine diazotrophic cyanobacteria Trichodesmium spp. I. Absorption and photosynthetic spectra, Limnol. Oceanogr., 44, 608, 1999. 

Glibert, P. M., and Bronk, D. A. (1994). Release of dissolved organic nitrogen by marine diazotrophic cyanobacteria, Trichodesmium spp. Appl. Environ. Microbiol. 60, 3996—4000. 

Needoba, J. A., Foster, R. A., Sakamoto, C., Zehr, J. P., and Johnson, K. S. (2007). Nitrogen fixation by uniceUular diazotrophic cyanobacteria in the temperate ohgotrophic North Pacific Ocean. 

Estimates of N2 fixation rates in the global ocean continue to rise as results emerge from studies with the main N2 fixer in the ocean Trichodesmium, the heterocystous endosymbiont Richelia, as well as more recently discovered N2 fixers including unicellular diazotrophic cyanobacteria and bacterioplankton (Capone et al, 1997 HanseU and Feely 2000 Karl et al, 1997 Lipschultz and Owens, 1996 Montoya et al., 2004 Zehr et al, 1998 and 2001). Trichodesmium is involved in N release directly, through release of amino acids, DON, and NH4 (reviewed in Table 8.2). Trichodesmium is also a source of NH4+ and DON as a result of remineralization by associated bacteria, sloppy feeding and excretion by grazers (SeUner, 1992 Sheridan et al, 2002). 

Reef sponges (Wilkinson and Fay, 1979) and some corals may acquire fixed nitrogen from associated diazotrophic cyanobacteria (Frias-Lopez et al., 2002 Lesser et al., 2004 Rohwer et al., 2001, 2002 Shashar et al., 1994a,b, see also Chapter 4, Capone and Carpenter, this volume). The nutritional significance of these alternative pathways remains to be fuUy evaluated. 

Lin, S., Henze, S., Lundgren, P., Bergaman, B., and Carpenter, E. J. (1998). Whole-ceU immunolo-calisation of nitrogenase in marine diazotrophic cyanobacteria Trichodesmium spp. Appl. Environ. Microbiol. 64, 3052—3058. 

Ohkouchi, N., Kashiyama, Y., Kuroda, Y., Ogawa, N. O., and Kitazato, H. (2006). The importance of diazotrophic cyanobacteria as primary producers during Cretaceous Oceanic Anoxic Event 2. Biogeosciences 3, 467—478. 

Falcon et al. (2005) examined the P04 requirements of Atlantic and Pacific unicellular diazotrophic cyanobacteria isolates, and found that half-saturation constants for growth ranged from 0.06 to 0.25 pM. These are similar to the growth halfsaturation constants of 0.14-0.22 pM reported for Trichodesmium by Fu et al. (2005b), suggesting that these unicellular N2-fixers would also be quite unhkely to meet their cellular P demands by relying on P04 at the reported concentrations in the oligotrophic oceans ( 5-40 nM, Table 38.1). 

Tuit, C., Waterbury, J., and Ravizza, G. (2004). Diel variation of molybdenum and iron in marine diazotrophic cyanobacteria. Limnol. Oceanogr. 49, 978—990. 

Summer Bloom The buoyant surface blooms of diazotrophic cyanobacteria (Nodularia spumigena. Aphanizomenon sp., Anabaena spp.) are the most impressive bloom phenomena in the Baltic Proper. Nodularia blooms are also of socioeconomic interest because they are potentially toxic (Wasmund, 2002). As diazotrophic cyanobacteria are not... 

Ohlendieck, U., Stuhr, A., Siegmund, H., 2000. Nitrogen fixation by diazotrophic cyanobacteria in the Baltic and transfer of the newly fixed nitrogen for picoplankton organisms. Journal of Marine Systems, 25, 213-219. 

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