Mutants algae

Biochemistry, From the inhibition assays with the wildtype (wt) and mutant algae it becomes evident that there are large differences in sensitivity not only to the diverse nitrophenols but also among the various mutants. The range of the pi50 values from Tables I and II is listed in Table III. 

The biflagellate unicellular green alga Chlamydomonas reinhardtii is prone to spontaneous mutations that produce deficiencies in flagellar proteins and MT assembly, substructure, and function. Viable mutants that are either nonmotile or slow moving can be isolated and analyzed biochemically and morphologically, thereby establishing structure-function correlations. Electron microscopic analysis... 

Kinetic studies of the incorporation of the " C-labelled precursors mevalonic acid, isopentenyl pyrophosphate, and phytoene into C40 carotenes by Halobac-terium cutirubrum cell-free preparations" produced results consistent with the pathways outlined in Schemes 2 and 3. Only the trans-isomers seemed to be involved. A mutant strain, " PGl, of the green alga Scenedesmus obliquus accumulates phytoene (135), phytofluene (136), and -carotene (137) in place of the... 

Waste treatment algae digesting proteins enzymes (plastic digesting enzymes obtained from mutant) Amoeba spp., Rhizopoda, Protozoa Polne-Fuller 1988... 

Chumpolkulwong, N. Kakizono, T. Handa, T. Nishio, N. (1997) Isolation and characterization of compactin resistant mutants of an astaxanthin synthesizing green alga Haematococcus pluvialis. Biotechnol. Lett., 19, 299-302. 

The electron donor to Chl+ in PSI of chloroplasts is the copper protein plastocyanin (Fig. 2-16). However, in some algae either plastocyanin or a cytochrome c can serve, depending upon the availability of copper or iron.345 Both QA and QB of PSI are phylloquinone in cyanobacteria but are plastoquinone-9 in chloroplasts. Mutant cyanobacteria, in which the pathway of phylloquinone synthesis is blocked, incorporate plasto-quinone-9 into the A-site.345a Plastoquinone has the structure shown in Fig. 15-24 with nine isoprenoid units in the side chain. Spinach chloroplasts also contain at least six other plastoquinones. Plastoquino-nes C, which are hydroxylated in side-chain positions, are widely distributed. In plastoquinones B these hydroxyl groups are acylated. Many other modifications exist including variations in the number of iso-prene units in the side chains.358 359 There are about five molecules of plastoquinone for each reaction center, and plastoquinones may serve as a kind of electron buffer between the two photosynthetic systems. 

Carter JN, Beatty KE, Simpson MT, Butler A (2002) Reactivity of Recombinant and Mutant Vanadium Bromoperoxidase from the Red Alga Corallina officinalis. J Inorg Biochem 91 59... 

Smeda et al. (1993) reported that in a mutation of the psb A gene in a photoautotropic potato, atrazine resistance was attributable to a mutation from AGT (ser) to ACT (threonine) in codon 264 of the psb A gene that encodes the Qb protein. Although the mutant cells exhibited extreme levels of resistance to atrazine, no concomitant reductions in photosynthetic electron transport or cell growth rates were detected compared to the unselected cells. This is in contrast with the losses in productivity observed in atrazine-resistant mutants that contain a Ser to Gly 264 alteration. Research has shown that triazine resistance by various algae and photosynthetic bacteria has been due to changes in many different binding sites (Oettmeier, 1999). 

Starch is formed in chloroplasts of moss, fern and green algae.18 Chlorophyceae (green algae) starch is similar to that of higher plants, and several species have been used in studies of starch biosynthesis.19,22,29 In a recent set of studies, Ball et al.22 used Chlamydomonas reinhardtii to study starch biosynthesis. They produced several Chlamydomonas mutants which produce starch with characteristics similar to starches produced by maize endosperm mutants.31-34 The various starch mutations of Chlamydomonas will be discussed in Section 3.7. Other classes of algae which produce starch are Prasinophyceae19,35 and Cryptophyceae.35,36... 

To the best of the present author s knowledge, there are, unfortunately, in the algae or higher plants, no known mutants available that are specifically blocked in cellulose synthesis. However, several, relatively specific, chemical inhibitors of the process have been characterized. One of these, coumarin, has been reported to inhibit cellulose synthesis in A. xylinum,10,159 as well as in higher plants.85,160 Relatively... 

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