Plankton micro

Biofilm, Planktonic Micro-Organisms, and Benthic Micro-Organisms... 

Very H-nch algae phyto- plankton micro- organisms amorphous H-nch Spores pollen cuticle amorphous H-Poor wood humic tissues coal amorphous NoH "Charcoal" oxidized tissues... 

The major purpose of monitoring microbes is to identify the generation of biofilms and to find the locations of biofilms, if any. The purpose of sanitization is to kill and destroy the biofilm after detecting the location of the biofilms. The planktonic population, whose number of micro-organisms in water is monitored, should be understood and utilized to indicate biofilms in the system. The number of microbes in water is an indicator of system contamination levels and is the basis for the system alert levels. 

Jackson, T.A. and Bistricki, T. (1995) Selective scavenging of copper, zinc, lead, and arsenic by iron and manganese oxyhydroxide coatings on plankton in lakes polluted with mine and smelter wastes results of energy dispersive X-ray micro- analysis. Journal of Geochemical Exploration, 52(1-2), 97-125. 

Considering the micro-environment close to the surface of plankton cells the existence of Fe(II) complexes has been observed, even in an aerobic environment (Morel, this volume). The macro-environment represents evidently not necessarily the same conditions as the micro-environment close to the organisms. 

Model of plankton blooms date back to the classical work of Riley et al. (19microbial organisms was incorporated in models of the pelagic plankton by Pomeroy (1979), Pace et al. (1984) and Fasham (1985). The above works have all treated plankton communities on a seasonal scale. In the model described below, we deal with a simple model of phytoplankton and micro-organisms concerned with the "microbial loop" (Azam et al., 1983) on a daily time scale appropriate to the turnover time of these organisms. The model is based on biomass data collected by Holligan et al. 

Fig. 4. Compartmental model describing the cycling of nitrogen in a planktonic community in the mixed layer of a water column. Flow pathways are represented by arrows and numbers which correspond to mathematical expressions described in Table 2. The nitrogen pool represents all abiotic nitrogen (nitrate, ammonia and urea), and other compartments represent bacteria, zooflagellates, larger protozoa, and micro-mesozooplankton, giving off waste products (F+U). Arrows (13) and (14) depict sedimentation of zooplankton faeces and phytoplankton cells, respectively (After Moloney et al., 1985).

The dominant allochthonous inputs are from riverine, marine/estuarine plankton, and bordering terrestrial wetland sources. Autochthonous sources typically include plankton, benthic and epiphytic micro- and macroalgae, emergent and submergent (e.g., seagrasses) aquatic vegetation (EAV and SAV) within the estuary proper, and secondary production. 

Bacteria within a biofilm may be less sensitive to antibacterial compounds than planktonic cells (reviewed in [150]). Several possible reasons (Table 4.9) can be put forward to account for this, notably reduced access of drug or biocide to cells within a biofilm, chemical reaction with the glycocalyx and modulation of the micro-environment [147], In addition, the attached cells may produce degradative enzymes although the significance of this... 

Quilliam, M.A., Aasen, I, Hardstaff, W.R., and Lewis, N. 2003. Analysis of phycotoxins in handpicked plankton cells by micro-column liquid chromatography-tandem mass spectrometry. In HABTech 2003, Cawthron Report No. 906, ed. Holland, P, Rhodes, L., and Brown, L. Nelson, New Zealand Cawthron Institute, 107-112. 

Cembella, A.D., Lewis, N.I., and Quilliam, M.A. 1999. Spirolide composition of micro-exfi acted pooled cells isolated from natural plankton assemblages and from cultiwes of file dinoflagellate Alexandrium ostenfeldii. Nat Toxins 7, 197—206. -------. 2000. The marine dinoflagellate Alexandrium ostenfeldii (Dinophyceae) as the causative organism of spirolide shellfish toxin. Phycologia 39, 61-1 A. 

We have seen how micro-organisms such as fungi, bacteria, and plankton can cause toxic contamination of food. Plants themselves may also have naturally occurring toxic constituents. For example, as we saw in the discussion on herbal remedies in Chapter 6, the pyrrolizidine alkaloids are found in many plants which may contaminate crops such as wheat and hence find their way into the food we consume. 

Fig. 6.11 Biomasses within different size fractions at comparable stations sampled by the US JGOFS (S2-S15) and ARABESQUE (A1-A6) investigators during (a) SWM and (b) NEM (see insets of Figs 6.4 and 6.6 for station locations). For each station there is a set of three bars showing contributions by pico (filled), nano (hatched) and micro (open) plankton. The bar in the middle is for autotrophs and the other two for heterotrophs. Reproduced from Garrison etal. (2000) with permission from Elsevier Science.

Examples of applications of X-ray spectrometric analytical techniques to elemental determinations in a variety of materials are presented in Table 2.12. Some recent applications papers may be mentioned. Total reflection XRF has been applied by Xie et al. (1998) to the multielement analysis of Chinese tea (Camellia sinensis), and by Pet-tersson and Olsson (1998) to the trace element analysis of milligram amounts of plankton and periphyton. The review by Morita etal. (1998) on the determination of mercury species in environmental and biological samples includes XRF methods. Alvarez et al. (2000) determined heavy metals in rainwaters by APDC precipitation and energy dispersive X-ray fluorescence. Other papers report on the trace element content of colostrum milk in Brazil by XRF (da Costa etal. 2002) and on the micro-heterogeneity study of trace elements in uses, MPI-DING and NIST glass reference materials by means of synchrotron micro-XRF (Kempenaers etal. 2003). 

Thus, it appears that water humus is the indispensable resistant product resulting from transformation, decomposition and synthesis of OM of excretions and dead remains of plankton in the ocean its final structure is largely determined by the activity of micro-organisms (Skopintsev, 1950). 

Droop, M.R. (2003) In defence of the cell quota model of micro-algal growth. Journal of Plankton Research 25, 103-107. 

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