| Title | RESPONSES OF BENTHIC BACTERIA TO EXPERIMENTAL DRYING IN SEDIMENTS FROM MEDITERRANEAN TEMPORARY RIVERS |
| Abstract | In the semiarid Mediterranean regions, water scarcity represents a common physiological stress for
microbial communities residing in river sediments. However, the effect of drying has not yet adequately been evaluated when analyzing riverine microbiological processes. The bacterial community structure (abundance, biomass, composition) and functioning (carbon production, live cell percentage) were assessed during experimental desiccation in microcosms with sediments from different Mediterranean temporary rivers (Tagliamento, Krathis, Mulargia, Pardiela). Our results showed that the overall responses to drying of the bacterial community were independent from sediment origin and strictly related to water content. During desiccation, a prompt decline (up to 100%) of the initial bacterial carbon production was followed by a slower decrease in abundance
and biomass, with an overall reduction of 74% and 78%, respectively. By the end of the experiment, live cells were still abundant but depressed in their main metabolic functions, thus resulting in a drastic increase in the community turnover time. Only 14% of the initial live cell biomass was available in dry sediments to immediately start the reactivation of the aquatic microbial food web after the arrival of new water. Community composition analysis showed a relative increase in alpha- and beta-Proteobacteria, when passing from wet to dry conditions. Our results suggest that the occurrence of drought events could affect carbon cycling through the freshwater microbial compartment, by temporarily limiting microbial mineralization and altering bacterial community structure. |
| Source | Microbial ecology 55 (2), pp. 270–279 |
| Journal | Microbial ecology |
| Editor | Springer-Verlag,, New York,, Stati Uniti d'America |
| Year | 2008 |
| Type | Articolo in rivista |
| DOI | 10.1007/s00248-007-9274-6 |
| Authors | AMALFITANO S., FAZI S., ZOPPINI A., BARRA CARACCIOLO A., GRENNI P., PUDDU A. |
| Text | 42258 2008 10.1007/s00248 007 9274 6 ISI Web of Science WOS 000252769500011 RESPONSES OF BENTHIC BACTERIA TO EXPERIMENTAL DRYING IN SEDIMENTS FROM MEDITERRANEAN TEMPORARY RIVERS AMALFITANO S., FAZI S., ZOPPINI A., BARRA CARACCIOLO A., GRENNI P., PUDDU A. Water Research Institute IRSA CNR , Via Reno 1, 00198 Rome, Italy In the semiarid Mediterranean regions, water scarcity represents a common physiological stress for microbial communities residing in river sediments. However, the effect of drying has not yet adequately been evaluated when analyzing riverine microbiological processes. The bacterial community structure abundance, biomass, composition and functioning carbon production, live cell percentage were assessed during experimental desiccation in microcosms with sediments from different Mediterranean temporary rivers Tagliamento, Krathis, Mulargia, Pardiela . Our results showed that the overall responses to drying of the bacterial community were independent from sediment origin and strictly related to water content. During desiccation, a prompt decline up to 100% of the initial bacterial carbon production was followed by a slower decrease in abundance and biomass, with an overall reduction of 74% and 78%, respectively. By the end of the experiment, live cells were still abundant but depressed in their main metabolic functions, thus resulting in a drastic increase in the community turnover time. Only 14% of the initial live cell biomass was available in dry sediments to immediately start the reactivation of the aquatic microbial food web after the arrival of new water. Community composition analysis showed a relative increase in alpha and beta Proteobacteria, when passing from wet to dry conditions. Our results suggest that the occurrence of drought events could affect carbon cycling through the freshwater microbial compartment, by temporarily limiting microbial mineralization and altering bacterial community structure. 55 RESPONSES OF BENTHIC BACTERIA TO EXPERIMENTAL DRYING IN SEDIMENTS FROM MEDITERRANEAN TEMPORARY RIVERS Amalfitano_2008_ME_Drying 0.pdf Articolo in rivista Springer Verlag, 0095 3628 Microbial ecology Microbial ecology Microb Ecol Microbial ecology. paola.grenni GRENNI PAOLA stefano.fazi FAZI STEFANO anna.barracaracciolo BARRA CARACCIOLO ANNA stefano.amalfitano AMALFITANO STEFANO alberto.puddu PUDDU ALBERTO annamaria.zoppini ZOPPINI ANNAMARIA TA.P02.002.003 Ruolo di comunita microbiche nella degradazione della sostanza organica e nella circolazione del carbonio nei sistemi acquatici |
