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• Introduction: Many studies deal with taxonomic diversity (TD) or estimation of functional traits of ectomycorrhizal communities. However, to our knowledge, none of them has ever tried to calculate the functional diversity (FD) of those communities, which is of critical importance for the diversity and reliability of nutrient supply to the tree. • Objectives: Here, we propose to evaluate the functional diversity of ECM communities in their potential ability to mobilise nutrients from organic matter, in two different forest stands. • Results: Results show that in both forest stands: - TD is strongly correlated with FD. - ECM species are functionally redundant within the communities for their abilities to secrete organic matter degrading enzymes. - The functional traits (enzymatic activities) of the studied ectomycorrhizal communities are not related within genera, nor within families or phylogenetically related groups of taxa. - Some species show a wide phenotypic plasticity for their enzymatic profiles. • Conclusion: This study provides the first evidence of functional redundancy in ectomycorrhizal communities. More studies are now needed to evaluate the robustness of these results at wider ecosystem scales and using other relevant functional traits. © The Author(s) 2011. Source

Fitzhenry K.,Marine Institute of Ireland | Barrett M.,Microbial Ecology Laboratory | O'Flaherty V.,Microbial Ecology Laboratory | Dore W.,Marine Institute of Ireland | And 3 more authors.
Water Practice and Technology | Year: 2014

Human pathogenic viruses (HPVs) with particular reference to norovirus (NoV) commonly known as ‘the winter vomiting bug’ is the leading causes of viral gastroenteritis worldwide. NoV is present in wastewater in high numbers and coupled with a low infectious dose can endanger public health. Secondary wastewater treatment processes are not designed to eradicate HPVs thus a tertiary disinfection step is required. Typical pathogen removal processes include slow sand filtration and membrane barrier methods. NoV cannot be cultured in a laboratory and so its sole detection is limited to expensive and time-consuming molecular methods. The use of an alternative virus, the FRNA bacteriophages has been suggested as a surrogate for NoV due to its physicochemical similarities and cultivability. This research focuses on the investigation of a barrier method of tertiary disinfection using membrane filters and tangential flow filtration. In addition to this, the suitability of FRNA bacteriophages as a cheaper alternative indicator of NoV was investigated. © IWA Publishing 2014. Source

Jain A.,Microbial Ecology Laboratory | Jain A.,Arctic Group | Meena R.M.,Microbial Ecology Laboratory | Naik R.K.,Southern Ocean Group | And 5 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2015

In a shipboard microcosm experiment we manipulated cobalt (Co), copper (Cu), iron (Fe), and Fe+Co availability in surface water samples collected during austral summer of 2013 from a Polar front (PF) location in the Indian Sector of Southern Ocean, to examine the responses of phytoplankton as well as bacterial community (BC) to these micronutrient amendments. Total chlorophyll a (Chl a) concentration increased significantly (. P<0.01) in all micronutrient-enriched microcosms (MEM), with the incubation period unlike in the control microcosms (CM). Bacterial abundance in Co, Fe and Fe+Co-enriched microcosms increased 1.5 fold within 5 days of incubation, unlike in other microcosms. Despite significant increase in Chl a, the DGGE banding pattern reflects minor differences in the BC. However, there were significant differences in relative abundance (i.e band intensity) of two most responsive phylotypes identified as Rhodospirillales and Rosebacter sp of Alphaproteobacteria group between MEM and CM. Strong correlation was not discernable between Chl a concentr. ation and bacterial abundance as well as BC structure. Apparently autotrophic processes in this region are not only limited by the availability of Fe, but also Co and Cu. © 2015 Elsevier Ltd. Source

Ramaiah N.,Microbial Ecology Laboratory | Jain A.,Microbial Ecology Laboratory | Jain A.,Arctic Group | Meena R.M.,Microbial Ecology Laboratory | And 9 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2015

The effects of micronutrient amendments such as cobalt (Co), copper (Cu), iron (Fe) and their mixture (Co+Cu+Fe) on bacterial abundance, phytoplankton, bacterial community (BC) composition were examined at a subtropical front (STF) location in the Indian Sector of the Southern Ocean (ISSO) during the austral summer of 2012. From the 15-day on-board experiment it became evident that there was no significant increase in total chlorophyll a concentration or phytoplankton cell numbers in micronutrient enriched microcosms (MEM) compared to the control microcosms (CM) with no added micronutrients. Highest bacterial abundance was observed in the Fe-enriched microcosm within 5 days of incubation unlike in other microcosms. Interestingly, significant differences in the BC composition were observed between MEM and CM. In that an increase of ~10 unique phylotypes affiliated with Psychrobacter sp, Prochlorococcus sp, Burkholderia sp, Cytophaga-. flavobactria cluster, Roseobacter sp, Bacillus sp and Vibrio sp was observed in the MEM. The phylotypes associated with Cyanobacteria preferentially responded to the Co and Fe additions, whereas the members of the Cytophaga-. Flavobacteria cluster responded to the Cu, Fe and mixture amendments. Our results are useful to discern that availability of micronutrients, in particular of Fe, affects the bacterial abundance as well as BC composition, but not the phytoplankton growth/chlorophyll a concentration in the STF location. In addition, micronutrient amendments ex-situ appears to lead to predominance of only a few bacterial phylotypes. This shift in bacterial community composition might be due to preferential and/or versatile utilization of exogenously added micronutrients. Phylogenetic diversity of culturable bacterial populations from this sampling location was also assessed using 99 pure bacterial cultures. For this, a select set of biochemical characteristics was examined and numerical profiling was done before subjecting to 16S rRNA sequencing based identification. This effort yielded close to 20 clusters, and representative isolates from each cluster were subjected to molecular taxonomic analyses using 16S rRNA marker gene. From this analysis, ~90% of bacterial isolates were found to be affiliated with Firmicutes and ~10% to Gammaproteobacteria suggesting preponderance of only a few phylotypes in the deep chlorophyll maximum zone of this STF location. © 2015 Elsevier Ltd. Source

Zabaloy M.C.,Microbial Ecology Laboratory | Carne I.,National University of Rosario | Viassolo R.,National University of Rosario | Gomez M.A.,Microbial Ecology Laboratory | Gomez E.,National University of Rosario
Pest Management Science | Year: 2015

BACKGROUND: A plot-scale experiment was conducted to assess the impact of field application rates of glyphosate on soil microbial communities by taking measurements of microbial activity (in terms of substrate-induced respiration and enzyme activity) in parallel with culture-independent approaches to assessing both bacterial abundance and diversity. Two rates of glyphosate, alone or in a mixture with 2,4-dichlorophenoxyacetic acid, were applied directly onto the soil surface, simulating normal use in chemical fallow in no-till systems. RESULTS: No consistent rate-dependent responses were observed in the microbial activity parameters investigated in the field plots that were exposed to glyphosate. Denaturant gradient gel electrophoresis (DGGE) of the overall bacterial community (Eubacteria) and ammonia-oxidising bacteria (AOB) revealed no effects of the high rate of glyphosate on the structure of the communities in comparison with the control. No treatment effects were observed on the abundance of Eubacteria shortly after treatment in 2010, while a small but significant difference between the high rate and the control was detected in the first sampling in 2011. The abundance of AOB was relatively low during the study, and treatment effects were undetectable. CONCLUSIONS: The absence of negative effects on soil microbial communities in this study suggests that glyphosate use at recommended rates poses low risk to the microbiota. © 2015 Society of Chemical Industry. Source

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