Cells, algal

Crude protein = %nitrogen X 6.25. Does not accurately reflect true protein content. Algal cells may contain nonprotein nitrogen substances, eg, 4—6% nucleic acids, dry wt basis. 

Evidence exists of differential sensitivity of algal cells to enhanced UV levels. 

The oxygen evolution rate was measured by using the photosynthetic activity measurement system (Fig. 1). When light was illuminated to the reaction vessel, algal cells began to evolve oxygen and the linearity between dissolved oxygen and time was observed just after a few... 

Crist, R.H., Oberholser, K., Shank, N., and Nguyen, M., Nature of bonding between metallic ions and algal cell walls, Environmental Science and Technology, 15, 1212-1217, 1981. 

Procedure Harvest the algal cells by centrifugation at 3000 rpm for 5 min at 4°C, then, wash the cells in distilled water thrice. Prepare three replicates for each treatment. Sonicate the algal cells under nitrogen condition at 14 MHz for 10 min to extract the membrane fatty acids. Add 2 ml of 2 M KOH in 95% (v/v) methanol and 2 ml of benzene to the sonicated cells. Fill the headspace with N2 gas and incubate the mixture at 80°C for 3 h. On cooling, add an equal volume of methanol and extract the non-saponified fraction by... 

DMSP. DMSP and related sulfur compounds generated by planktonic microalgae are involved in a complex series of interactions and reactions that occur in seawater and the atmosphere (Malin et al. 1992 Liss et al. 1994 Malin 1996 Malin and Kirst 1997 Steinke et al. 2002 Yoch 2002). In the oceans, DMS can originate from DMSP that is cleaved during grazing, be directly released by healthy algal cells, or be released when cells senesce or are lysed by viruses (Fig. 8.3). 

From the previously discussed studies, the oxidative burst response appears to integrate and/or orchestrate several defense responses. These provide an adaptive mechanism to counteract attacks on or injury to algal cells and thalli. As shown in Fig. 12.2, the occurrence of an oxidative burst associated with the perception of cell-free extracts of A. operculata was shown to play a crucial role in the natural resistance of C. crispus gametophytes (Bouarab et al. 1999). 

Vardi A, Formiggini F, Casotti R, De Martino A, Ribalet F, Miralto A, Bowler C (2006) A stress surveillance system based on calcium and nitric oxide in marine diatoms. PLoS Biol 4 411 119 Vorwerk S, Somerville S, Somerville C (2004) The role of plant cell wall polysaccharide composition in disease resistance. Trends Plant Sci 9 203-209 Vreeland V, Laetsch WM (1990) A gelling carbohydrate in algal cell wall formation. In Adair WS, Mecham RP (eds) Organization and assembly of plant and animal extracellular matrix. Academic, San Diego, CA, ppl 37—171... 

Sporopollenin is a complex polymer made up of a diversity of aromatic and aliphatic residues, which occurs in many algal cell walls where it non-specifically attenuates UV radiation (Xiong et al. 1997). It may therefore act as a constitutive UV sunscreen compound. 

Plastids Self-replicating cytoplasmic organelles of plant and algal cells that contain pigments and may synthesize and accumulate various substances. Plastids are used in phylogenetic studies. [NIH]... 

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