Cyanobacterium

The water fern is unique in being the only known fern genus to associate symbioticaHy with a N -fixing cyanobacterium, Jinabaena a Uae. It is... 

Synthetic study of 4-thiazoline derivative curacin A, a novel antimitotic agent isolated from cyanobacterium Lyngbya majuscula 99YGK552. 

Photochemical methods [6] have been developed to provide an environmentally friendly system that employs light energy to regenerate NAD(P)H, for example, by the use of a cyanobacterium, a photo synthetic biocatalyst. Using the biocatalysts, the... 

A shift in temperature from 38 to 22 °C leads to desaturation of fatty acids in Anabaena variabilis [110], resulting in control of the fluidity of the plasma membrane. Mutants have been isolated in Synechocystis PCC 6803 that were defective in desaturation of fatty acids, and the growth rate of one of these mutants was much lower than that of the wild-type at 22 °C [112]. It turned out that the mutant strain had a mutation in the gene desA, and when the wild-type allele was introduced into the chilling-sensitive cyanobacterium Anacystis nidulans, it resulted in increasing the tolerance of that strain to low temperature [113]. These experiments nicely demonstrate the existence of a mechanism of adaptation to low temperature in a chilling-tolerant cyanobacterium. 

Figure 1. Left Anatoxin-a (ANTX-A) hydrochloride. Produced by the freshwater filamentous cyanobacterium Anabaena flos-aquae NRC-44-1. Right Anatoxin-a(s). Produced by the freshwater filamentous cyanobacterium Anabaena flos-aquae NRC-525-17. Bottom Aphantoxin-I (neosaxitoxin) and Aphantoxin-II (saxitoxin) produced by certain strains of the filamentous cyanobacterium Aphantomenon flos-aquae.

Figure 8. Left The cyclic heptapeptide hepatotoxin microcystin-LA (cyanoginosin-LA) produced by the colonial cyanobacterium Microcystis aeruginosa strain WR-70 (UV-010). MW = 909. Right The cyclic heptapeptide hepatotoxin microcystin-LR (cyanoginosin-LR) produced by a waterbloom of the colonial cyanobacterium Microcystis aeruginosa collected in Lake Akersvatn, Norway, 1984-85 MW=994, 69J1).

HSCCC was successfully applied for the first time to the isolation and purification of zeaxanthin from cyanobacterium Microcystis aeruginosa. Adducts of flavonols and anthocyans were also isolated using this method. ... 

Masamoto, K. et al.. Identification of a gene required for cis-to-trans carotene isomerization in carotenogenesis of the cyanobacterium Synechocystis sp. PCC 6803, Plant Cell Physiol. 42, 1398, 2001. 

Indeed, recent research on the use of a cyanobacterium as a biocatalyst has opened up this area asymmetric reduction of ketones by a cyanobacteria, Syne-chococcus elongates PCC 7942, with the aid of light energy proceeded smoothly... 

A large amount of biocatalyst is usually required to reduce a considerable amount of substrate (the b/s for baker s yeast is about 50-350). On the contrary, a low b/s ratio (2.6-0.5) could be achieved using the cyanobacteria. The improvement in the b s ratio is caused by the fact that the cyanobacterium can utilize the power of light effectively to reduce the substrate. 

Ketones used in this report are reduced by the cyanobacterium with excellent enan-tioselectivities (> 96% ee). An enzyme exhibiting high enantioselectivity usually shows a relatively strict substrate specificity hence, there scarcely is a catalyst that reacts with many kinds of substrates and also shows high select vities. This alga can reduce a wide variety of aryl methyl ketones and afford the corresponding alcohols with high enantioselectivities. 

The reduction of a,a-difluoroacetophenone by a cyanobacterium proceeded both under light and in the dark, and the poor enantioselectivities (20-30% ee) observed in the dark were improved by irradiation. Thus, the enantioselectivities increased according to the lightness (70% ee under light (1000 lux)). The use of DCMU, a photosynthetic inhibitor, decreased the enantioselectivity of the reduction even under light conditions. The stereochemical course of the reduction is controlled by illumination or by adding DCMU. ... 

Genes encoding glucose transporters have recently been cloned from three photosynthetic organisms, the prokaryotic cyanobacterium Synechocystis [208,209], the... 

Cerniglia CE, C van Baalen, DT Gibson (1980a) Oxidation of biphenyl by the cyanobacterium, 1 sp. strain iCU. Arch Microbiol 125 203-207. 

Kuritz T, LV Bocanera, NS Rivera (1997) Dechlorination of lindane by the cyanobacterium Anabaena sp. 

Narro ML, CE Cerniglia, C Van Baalen, DT Gibson (1992) Metabolism of phenanthrene by the marine cyanobacterium Agmc c// m quadruplicatum PR-6. Appl Environ Microbiol 58 1351-1359. 

Olafson RW, WD McCubbin, CM Kay (1988) Primary- and secondary-structural analysis of a unique prokaryotic metallothionein from a Synechococcus sp. cyanobacterium. Biochem J 251 691-699. 

Figure 8.21c) (Dalton et al. 1981 Cemiglia et al. 1984a,b Adriaens 1994) including the marine cyanobacterium Oscillatoria sp. (Narro et al. 1992a,b). 

Narro ML, CE Cemiglia, C van Baalen, DT Gibson (1992a) Evidence for an NIH shift in oxidation of naphthalene by the marine cyanobacterium Oscillatoria sp. strain JCM. Appl Environ Microbiol 58 1360-1363. 

In contrast to the photosynthetic eukaryotes, photoprotection in cyanobacteria is not induced by the presence of a transthylakoid ApH or the excitation pressure on PSII. Instead, intense blue-green light (400-550 nm) induces a quenching of PSII fluorescence that is reversible in minutes even in the presence of translation inhibitors (El Bissati et al. 2000). Fluorescence spectra measurements and the study of the NPQ mechanism in phycobilisome- and PSII-mutants of the cyanobacterium Synechocystis PCC6803 indicate that this mechanism involves a specific decrease of the fluorescence emission of the phycobilisomes and a decrease of the energy transfer from the phycobilisomes to the RCs (Scott et al. 2006, Wilson et al. 2006). The site of the quenching appears to be the core of the phycobilisome (Scott et al. 2006, Wilson et al. 2006, Rakhimberdieva et al. 2007b). 

El Bissati, K., E. Delphin, N. Murata, A. Etienne, and D. Kirilovsky (2000). Photosystem II fluorescence quenching in the cyanobacterium Synechocystis PCC 6803 Involvement of two different mechanisms. Biochim Biophys Acta 1457(3) 229-242. 

Fulda, S., S. Mikkat, F. Huang et al. (2006). Proteome analysis of salt stress response in the cyanobacterium Synechocystis sp. strain PCC 6803. Proteomics 6(9) 2733-2745. 

Kucho, K.-I., Y. Tsuchiya, Y. Okumoto et al. (2004). Construction of unmodified oligonucleotide-based arrays in the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 Screening of the candidates for circadianly expressed genes. Genes Genet Syst 79 319-329. 

Mullineaux, C. W. (1992). Excitation energy transfer from phycobilisomes to photosystem-I in a cyanobacterium. Biochim Biophys Acta 1100(3) 285-292. 

Polfvka, T., C. A. Kerfeld, T. Pascher, and V. Sundstrom (2005). Spectroscopic properties of the carotenoid 3 -hydroxyechinenone in the orange carotenoid protein from the cyanobacterium Arthrospira maxima. Biochemistry 44(10) 3994—4003. 

Rakhimberdieva, M. G., V. A. Boichenko, N. V. Karapetyan, and I. N. Stadnichuk (2001). Interaction of phy-cobilisomes with photosystem B dimers and photosystem I monomers and trimers in the cyanobacterium Spirulina platensis. Biochemistry 40(51) 15780-15788. 

Rakhimberdieva, M. G., D. V. Vavilin, W. F. Vermaas, I. V. Elanskaya, and N. V. Karapetyan (2007b). Phycobilin/ chlorophyll excitation equilibration upon carotenoid-induced non-photochemical fluorescence quenching in phycobilisomes of the cyanobacterium Synechocystis sp. PCC 6803. Biochim Biophys Acta 1767(6) 757-765. 

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