Habitats, marine

Dissimilatory sulfate reducers such as Desul-fovibrio derive their energy from the anaerobic oxidation of organic compounds such as lactic acid and acetic acid. Sulfate is reduced and large amounts of hydrogen sulfide are generated in this process. The black sediments of aquatic habitats that smell of sulfide are due to the activities of these bacteria. The black coloration is caused by the formation of metal sulfides, primarily iron sulfide. These bacteria are especially important in marine habitats because of the high concentrations of sulfate that exists there. 

The first step in discovering a marine natural product lead compound involves accumulating collections of the source organisms. Ideally the collections would include as many species as possible collected from a large number of sites reflecting the wide diversity of habitats found in the world s oceans. The development of SCUBA and both manned and remotely operated (ROV) submersibles has provided the technology required to effectively collect algae and invertebrate specimens from most marine habitats. Consequently, the major issue... 

The tropical regions represent the oldest marine habitats, where red and green algae dominate, while brown algae are more abundant toward cold temperate regions. The diversity of marine fauna reaches a maximum in tropical seas, and many hypotheses have been proposed to explain this (Krebs 2001 Willig et al. 2003 ... 

C. Raghukumar, C. Mohandass, S. Kamat and M.S. Shailaja, Simultaneous detoxification and decolorization of molasses spent wash by the immobilized white-rot fungus Flavodon flavus isolated from a marine habitat. Enz. Microbiol. Technol. 35 (2004) 197-202. 

The potential adverse effects of inoculating very large numbers of a parasite, even a naturally occurring one, into a marine habitat to control a pest organismHowever, other types... 

However, one has to bear in mind that the microbial ecology of marine habitats has been revolutionized by cultivation-independent analyses based on 16S rRNA. It is now well documented that only a fraction of the marine microbial diversity has been cultivated, presumably far less than 1% [17], no more than the tip of the iceberg [18]. Clone fibraries of marine bacterioplankton 16S rRNA genes are dominated by a few phylotypes that have not been cultivated to date, and which are distributed globally [19,20]. It can therefore be concluded that the true marine microorganisms are in most cases presently not known. 

ICES (2004). Report of the Working Group on Biological Effect of Contaminants. ICES Document CM 2004/E 04 Ref ACME. International Council for the Exploration of the Sea (ICES), Marine Habitat Committee, Copenhagen, Denmark. 

Gerard, J. Lloyd, R. Barsby, T. Haden, P. Kelly, M.T. Andersen, R.J. (1997) Massetolides A-H, antimycobacterial cyclic depsipeptides produced by two pseudomonads isolated from marine habitats. J. Nat. Prod., 60, 223-9. 

Reflect on Findings. As frequendy happens in science, McClintock and Bakers results led to new questions. What are the properties of pteroenone Does this substance have potential for treating human disease In fact, the majority of the drugs prescribed in the United States were developed by chemists working with naturally occurring material. As we explore further in Chapter 14, this is an important reason to preserve marine habitats and tropical rain forests, which house coundess yet-to-be-discovered substances. 

Table 7.11. Comparison of the level of POPs contamination in cetaceans of Hong Kong and other marine habitats... 

Abele, L.G., Species diversity of decapod crustaceans in marine habitats, Ecology, 55, 156, 1974. 

The synthesis of secondary metabolites requires materials in the form of atoms that compose the secondary metabolites, energy to form covalent bonds between the atoms, the enzymes that carry out the formation reactions, the genetic material that codes and synthesizes the enzymes, and the cellular machinery that maintains pH, ionic strength, and redox potentials within a range that allow enzymes to function properly.85 Some materials such as hydrogen and oxygen are readily available and cheap, and contribute little to the material cost of synthesis. Other materials such as phosphorus and nitrogen are of limited supply in many marine habitats.86 The use of these rare materials in secondary metabolites is probably costly as they limit many primary metabolic pathways, which helps explain the rarity of secondary metabolites that contain N or P.2 Fixed carbon... 

Hay, M.E., The functional morphology of turf forming seaweeds persistence in stressful marine habitats, Ecology, 62, 739, 1981. 

Artificial Reef Evaluation with Application to Natural Marine Habitats, William Seaman, Jr. 

The coloration in green algae is due to chlorophyll a and b. Most of the species are aquatic, and are found commonly in fresh water and marine habitats some are terrestrial, growing in soil, trees, or rocks. Some are symbiotic with fungi, others are symbiotic with animals, e.g., the fresh water coelenterate Hydra has a symbiotic species of chlorella. Chlorella is sold as a health supplement (Wong and Cheung, 2000). 

Nereus Pharmaceuticals (20 000 unique stains from marine habitats) ... 

Despite enormous efforts in recent years to access new microbial sources, actinomycetes continue to be the largest group of microbial producers of biologically active natural products. Even though the genera of the Streptomyces family maintains the dominant position of secondary metabolite producers, rare actinomycetes from terrestrial, as well as marine habitats, are becoming excellent sources of new potential lead compounds. 

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