Extraction of marine organisms

Marine organisms are a well-established source of unique and biologically active peptides. Complex cyclic peptides and depsipeptides have emerged as an important new class of metabolites present in extracts of marine organisms. Many of these peptides have been found to be extremely potent cytotoxic and /or enzyme inhibitors. 

Our explanation for the absence of odd-carbon preference in marine organic matter is based on the fact that this absence is also seen in extracts of marine organisms and of bacterial cells. Our evidence from slope sediments suggests that the strong bacterial impression on normal marine, deep water sedimentary organic matter produces both features. 

Slauenwhite, D. E., and Wangersky, P. J. (1996). Extraction of marine organic matter on XAD-2 Effect of sample acidification and development of an in situ pre-acidification technique. Mar. Chem. 54,107-117. 

Henrikson, A.A. and Pawlik, J.R., Seasonal variation in biofouling of gels containing extracts of marine organisms, Biofouling, 12, 245, 1998. 

Dunlap, W. Llewellyn, L. Doyle, J. Yamamoto, Y. A microtiter plate assay for screening antioxidant activity in extracts of marine organisms. Mar. Biotechnol. 2003, 5, 294-301. 

After several decades of research, fundamental aspects of the chemical composition and structure of marine organic matter remain elusive. Advances in the chemical characterization of marine organic matter are, in large part, dependent on the development of quantitative methods for its concentration and isolation from seawater. Each of the major methods currently used for the isolation of marine DOM recovers around one-third of the DOM in seawater (solid-phase extractions, using XAD resins or C18 adsorbents, and ultrafiltration). A coupled reverse osmosis-electrodi-alysis method has recently been used to recover an average of 75% 12% of marine DOM from 16 seawater samples however, the method has emerged too recently to have been well tested at this time. 

A detailed interlaboratory study of arsenic speciation in six different kinds of marine organisms was published (El Moll et al., 1996). Detection of arsenic species in the sample extracts was performed by means of LC-ICP-OES for AB and AC, and by HG-AAS for As111, Asv, MMA and DMA. Many precautions were taken to avoid contamination and losses of analytes, and to improve the accuracy of the results. Data for total As, extractable As, residual As and AB were reported. 

Other marine organisms and microorganisms besides algae have also been found to be active against several viruses, such as marine Vibrio spp. which was active against infections caused by the hematopoietic necrosis virus and Oncorhynchus masou virus [129], and the aqueous extracts of marine cephalopods, which inhibited the Moloney murine leukaemia virus RT activity [130]. 

A variety of parameters are used to assess organic matter sotrrces. Btrlk parameters have the advantage that they are representative of total organic matter, whereas molectrlar parameters address only part of the extractable organic matter, which in turn is only a small portion of total organic matter. Some successfirl applications of molectrlar parameters show that the small bitumen fraction may be representative of the total, but there are many other examples where this is not the case. On the other hand, oxidation of marine organic... 

A fairly limited range of solvents has been utilized for the extraction of trace organic species from seawater. Hexane is a common choice though many others have also been used. Recent trends have been to replace hexane with either pentane or heptane because of the lower toxicity of these alternatives. Strict regulations now apply to safety aspects of the use of solvents at sea and these must not be neglected by the marine analyst when devising new methodologies. 

Fisheries science is concerned with the continued extraction of aquatic organisms from marine, brackish, and freshwater environments for subsistence, commercial, or recreational purposes. As such, fisheries science necessarily involves issues of yield (the numbers of fish harvested from a given stock) and sustainability (the numbers of fish that must not be harvested if the particular fish stock is to demonstrate continued productivity). This seemingly simple biological situation, however, is made much more complex by ecological, economic, and social considerations. 

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