As noted by Sheehan (1989) 'the main purpose of replication is the supply an estimate of variability (error) by which significance of treatment and control comparisons can be judged.' Thus, replication is needed to distinguish between natural variation and variation due to a treatment (such as introduction of a toxin into a microcosm) in an experiment. In fact, replication is one of the 'minimal requirements of experimental design in ecology' (Hairston, 1989) as in any application of the scientific method. It is included in this discussion because of its critical nature to the 'microcosm method' (Beyers, 1964) and because its consideration leads to fundamental questions of variability (possibly chaos) of ecosystems. Environ Microbiol 7: 1426–1441.Replication is an issue of experimental design rather than technical design of a microcosm. Yakimov MM, Denaro R, Genovese M, Cappello S, D’Auria G, Chernikova TN, Timmis KN, Golyshin PN, Giluliano L (2005) Natural microbial diversity in superficial sediments of Milazzo Harbor (Sicily) and community successions during microcosm enrichment with various hydrocarbons. Watson IA, Oswald SE, Mayer KU, Wu YX, Banwart SA (2003) Modeling kinetic processes controlling hydrogen and acetate concentrations in an aquifer-derived microcosm.

Syutsubo K, Kishira H, Harayama S (2001) Development of specific oligonucleotide probes for the identification and in situ detection of hydrocarbon-degrading Alcanivorax strains. Röling WFM, Milner MG, Jones DM, Lee K, Daniel F, Swannell RJP, Head IM (2002) Robust hydrocarbon degradation and dynamics of bacterial communities during nutrient-enhanced oil spill bioremediation. Röling WFM, Milner MG, Jones DM, Fratepietro F, Swannell RPJ, Daniel F, Head IM (2004b) Bacterial community dynamics and hydrocarbon degradation during a field-scale evaluation of bioremediation on a mudflat beach contaminated with buried oil.

Röling WFM, de Brito IRC, Swannell RPJ, Head IM (2004a) Response of archaeal communities in beach sediments to spilled oil and bioremediation. In Advances in Microbial Ecology, KC Marshall (ed.). Pritchard PH, Bourquin AW (1984) The use of microcosms for evaluation of interactions between pollutants and microorganisms. Pallud C, Meile C, Laverman AM, Abell J, Van Cappellen P (2007) The use of flow-through sediment reactors in biogeochemical kinetics: Methodology and examples of applications.

McKew BA, Coulon F, Yakimov MM, Denaro R, Genovese M, Smith CJ, Osborn AM, Timmis KN, McGenity TJ (2007b) Efficacy of intervention strategies for bioremediation of crude oil in marine systems and effects on indigenous hydrocarbonoclastic bacteria. McKew BA, Coulon F, Osborn AM, Timmis KN, McGenity TJ (2007a) Determining the identity and roles of oil-metabolizing marine bacteria from the Thames estuary, UK. Liou JS-C, DeRito CM, Madsen EL (2008) Field-based and laboratory stable isotope probing surveys of the identities of both aerobic and anaerobic benzene-metabolizing microorganisms in freshwater sediment. Kasai Y, Kishira H, Sasaki T, Syutsubo K, Watanabe K, Harayama S (2002) Predominant growth of Alcanivorax strains in oil-contaminated and nutrient-supplemented sea water. Herrmann S, Kleinsteuber S, Neu TR, Richnow HH, Vogt C (2008) Enrichment of anaerobic benzene-degrading microorganisms by in situ microcosms. Hernandez-Raquet G, Budzinski H, Caumette P, Dabert P, Le Ménach K (2006) Molecular diversity studies of bacterial communities of oil polluted microbial mats from the Etang de Berre (France). Hendrickx B, Dejonghe W, Boënne W, Brennerova M, Cernik M, Lederer T, Bucheli-Witschel M, Bastiaens L, Verstraete W, Top EM, Diels L, Springael D (2005) Dynamics of an oligotrophic bacterial aquifer community during contact with a groundwater plume contaminated with benzene toluene, ethylbenzene, and xylenes: an in situ mesocosm study. Head IM, Jones DM, Röling WFM (2006) Marine microorganisms make a meal of oil. Appl Environ Microbiol 73: 6089–6097.Ĭoulon F, McKew BA, Osborn AM, McGenity TJ, Timmis KN (2007) Effects of temperature and biostimulation on oil-degrading microbial communities in temperate estuarine waters. Bordenave S, Goñi-Urriza MS, Caumette P, Duran R (2007) Effects of heavy fuel oil on the bacterial community structure of a pristine microbial mat.

Example of microcosm