Browsing by Author "Henriques, Isabel S."
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- Bacterial community and system performance of an aerobic granular sludge reactor treating pharmaceutical wastewaterPublication . Amorim, Catarina L.; Moreira, Irina S.; Ribeiro, Ana R.; Tiritan, Maria E.; Henriques, Isabel S.; Castro, Paula M.L.Pharmaceuticals often reach wastewater treatment systems where low removal rates are observed. In the present study the potential impact of a mixture of such micro-pollutants on an aerobic granular sludge-sequencing batch reactor (AGS-SBR) was investigated using a lab-scale bioreactor. COD and P- removals were affected due to the load of pharmaceuticals resulting in a decrease of the COD uptake and the P-release during the anaerobic feeding phase, but the discharge limits were not exceeded. Nevertheless, both processes returned to its normal operation after resuming the pharmaceuticals feeding. The nitrification process was also affected but the activity of bacteria responsible for both nitrification steps was able to recover. The exposure to the pharmaceuticals induced alterations in the bacterial community structure.
- Biodegradation of 2-fluorobenzoate in upflow fixed bed bioreactors operated with different growth support materialsPublication . Emanuelsson, Maria A.E.; Henriques, Isabel S.; Jorge, Ruben M Ferreira; Castro, Paula M. L.Three upflow fixed bed bioreactors treating an aqueous stream containing 2-fluorobenzoate were operated for a period of 7months, during which they were exposed to high organic loading rates and starvation. The reactors contained granular activated carbon (GAC), polyethylene (PE) particles and expanded clay (EC) respectively as growth support for microbial biofilms. The performance of the reactors was compared and the biofilm microbial population was followed by cell counting and denaturing gradient gel electrophoresis (DGGE). The reactor containing GAC always had 100% removal efficiency owing to the adsorption properties of thematerial combined with biodegradation. The GAC reactor also recovered better after starvation periods in the sense that it showed more stable behaviour than the reactors containing EC and PE. The highest biological elimination capacity was observed for the reactor containing EC, which reached 200mg day−1 L−1 during reactor start-up, but during long-termoperation the reactor containing GAC showed the highest biological elimination capacity, 140mg day−1 L−1. DGGE analysis indicated that starvation periods seemed to be responsible for shifts in the microbial population.
- Changes in the bacterial community structure in two-stage constructed wetlands with different plants for industrial wastewater treatmentPublication . Calheiros, Cristina S.C.; Duque, Anouk F.; Moura, Alexandra; Henriques, Isabel S.; Correia, António; Rangel, António O.S.S.; Castro, Paula M.L.This study focused on the diversity of bacterial communities from two series of two-stage constructed wetlands (CWs) treating tannery wastewater, under different hydraulic conditions. Series were separately planted with Typha latifolia and Phragmites australis in expanded clay aggregates and operated for 31 months. The effect of plant species, hydraulic loading and unit stage on bacterial communities was addressed through bacterial enumeration and denaturating gradient gel electrophoresis (DGGE). Diverse and distinct bacterial communities were found in each system unit, which was related in part to the type of plant and stage position (first or second unit in the series). Numerical analysis of DGGE profiles showed high diversity in each unit with an even distribution of species. No clear relation was established between the sample collection time, hydraulic loading applied and the bacterial diversity. Isolates retrieved from plant roots and substrates of CWs were affiliated with c-Proteobacteria, Firmicutes, a-Proteobacteria, Sphingobacteria, Actinobacteria and Bacteroidetes. Both series were effective in removing organic matter from the inlet wastewater, however, based on batch degradation experiments it seems that biodegradation was limited by the recalcitrant properties of the wastewater
- Insights into the genome of Labrys portucalensis F11 and Rhodococcus sp. FP1, versatile xenobiotic-degrading bacteria isolated from an industrial contaminated soilPublication . Amorim, Catarina L.; Moreira, Irina S.; Henriques, Isabel S.; Castro, Paula M.L.Bacteria play an important role in the cleanup of contaminated sites due to their ability to degrade an impressive variety of xenobiotic compounds, using them as carbon and energy source. Two xenobiotic-degrading bacteria, namely Labrys portucalensis F11 and Rhodococcus sp. FP1, were previously isolated from industrially contaminated sediments collected at Estarreja, northern Portugal, which is known for its large industrial chemical complex (from the 1950s). Both strains have versatile catabolic routes for the bioconversion of several xenobiotic compounds including pharmaceuticals (e.g. fluoroquinolones [1], fluoxetine [2], diclofenac and estradiols (ongoing work)) and industrial and agro-chemical compounds (e.g. fluorobenzene [3], fluorophenol [4], fluoroanilines [5] and bisphenols (ongoing work)). The whole-genome sequencing and assembly of the two xenobiotic-degrading bacteria and further functional annotation using the Rapid Annotation using Subsystems Technology (RAST) server was carried out. Assembled genomes are composed of 7,952,755 bp (F11) and 9,630,728 bp (FP1) with GC contents of 63.5 and 67.2%, respectively. Moreover, the draft genome sequence of strain F11 contains 7406 predicted coding DNA sequences (CDSs) that were classified into 505 different subsystems, whereas FP1 contains 9094 CDSs distributed by 454 subsystems. On both cases, the most abundant systems are those involved in the metabolism of amino acid derivatives and carbohydrates. In addition, both genomes harbor genes for the metabolism of aromatic compounds with about 3.2 and 4.5% of the total encoding genes of F11 and FP1 related to that feature. Gene clusters likely encoding different peripheral pathways for the aromatic compounds degradation such as benzoate, quinate, toluene, byphenyl and choloaromatics were found. Moreover, catechol 1,2-dioxygenases, catechol 2,3-dioxygenase and protocatechuate 3,4-dioxygenases encoding genes of the central pathway in the metabolism of various aromatic compounds were also present. In silico and experimental analysis revealed that F11 and FP1 had versatile catabolic metabolism of various aromatic xenobiotics, hence being good candidates to recycle xenobiotic compounds back into natural biogeochemical cycles. These new insights could help devising strategies for bioaugmentation of environments polluted with xenobiotics. Keywords: Whole-genome sequencing; xenobiotic-degrading bacteria; Labrys portucalensis F11; Rhodococcus sp. FP1.
- Long term performance of constructed wetlands for tannery wastewater treatmentPublication . Calheiros, Cristina S. C.; Duque, Anouk F.; Moura, Alexandra; Henriques, Isabel S.; Correia, António; Rangel, António O. S. S.; Castro, Paula M. L.
- Microbial population dynamics within aerobic granular sludge exposed to a mixture of pharmaceuticalsPublication . Amorim, Catarina L.; Henriques, Isabel S.; Castro, Paula M. L.
- Substrate effect on bacterial communities from constructed wetlands planted with Typha latifolia treating industrial wastewaterPublication . Calheiros, Cristina S.C.; Duque, Anouk F.; Moura, Alexandra; Henriques, Isabel S.; Correia, António; Rangel, António O.S.S.; Castro, Paula M.L.Constructed wetlands (CWs) have been recognized as being able to effectively treat wastewater from municipal and industrial sources. This study focused on the effect of different substrates and long-term operation of horizontal subsurface flowCWstreating tannery wastewater on the bacterial communities. The CWs were planted with Typha latifolia in three types of substrate: two units with different types of expanded clay aggregates and one unit with fine gravel. Another unit with expanded clay was left unvegetated. Changes in the bacterial community related to the type of substrate, different hydraulic loading rates and along CW operationwere examined using denaturating gradient gel electrophoresis (DGGE). Bacterial enumerationwas also performed and several bacterial isolateswere retrieved from the CWs. Phylogenetic affiliations of those isolates were obtained on the basis of 16S rRNA gene sequences and revealed that they were closely related to the genera Bacillus (TM1S1, TM1R3, TNR1 and TAR1), Paracoccus (TM1R2), Pseudomonas (TM1R1) and Halomonas (TM1S2). The type of substrate and the presence of T. latifolia had a major effect on the species richness and the structure of bacterial communities as inferred by numerical analysis of DGGE profiles.