Q10 of heterotrophic activity during aerobic decomposition of Utricularia breviscapa and its effect on carbon cycling in a tropical lagoon

Brazilian Journal of Biology

Mb Cunha-santino²  I Bianchini Júnior¹ 

[1] ,Universidade Federal de São Carlos Departamento de Hidrobiologia São Carlos SP ,Brazil

关键词: Q10;    stoichiometric coefficient;    oxygen uptake;    aquatic macrophyte;    mathematical model;    Q10;    coeficientes estequiométricos;    consumo de oxigênio;    macrófita aquática;    modelo matemático;   

DOI  :  10.1590/S1519-69842010000200013

来源: SciELO

【 摘 要 】

In this study the Q10 coefficients of heterotrophic activities were measured during aerobic decomposition of Utricularia breviscapa Wright ex Griseb from Óleo lagoon (21° 36' S and 49° 47' W), Luiz Antonio, SP. The bioassays were set up with fragments of U. breviscapa and incubated with lagoon water at distinct temperatures (15.3, 20.8, 25.7 and 30.3 °C). Periodically for 95 days, the concentrations of dissolved oxygen were determined in the bioassays. The results of the temporal variation of dissolved oxygen were fitted to a first-order kinetic model. The stoichiometric relations were calculated on the basis of these fittings. In general, the results allowed us to conclude: i) the oxygen/carbon stoichiometric relations (O/C) varied in function of temperature and time. The temporal variations of the O/C observed in the decomposition of U. breviscapa, suggest that, in the initial phases of the process, low organic carbon concentrations were enough to generate great demands of oxygen, ii) the oxygen consumption coefficients (k d) presented low variation in function of increasing temperature, iii) the increment of the temperature induced a higher consumption of oxygen (COmax) and iv) the simulations indicate that during summer, temperature activates the metabolism of decomposing microbiota.

【 授权许可】

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