114 research outputs found
Simplified engineering design towards a competitive lipid-rich effluents valorization
Medium- and long-chain fatty acids and glycerol contained in the oily fraction of many food-industry effluents
are excellent candidates to produce biobased high-value triacylglycerides (TAGs) and polyhydroxyalkanoates
(PHAs). The typical process configuration for TAGs recovery from lipid-rich streams always includes two steps
(culture enrichment plus storage compounds accumulation) whereas, for PHAs production, an additional pretreatment
of the substrate for the obtainment of soluble volatile fatty acids (VFAs) is required. To simplify the
process, substrate hydrolysis, culture enrichment, and accumulation (TAG and PHA storage) were coupled here
in a single sequencing batch reactor (SBR) operated under the double growth limitation strategy (DGL) and fed in
pulses with industrial waste fish oil during the whole feast phase. When the SBR was operated in 12 h cycles, it
was reached up to 51 wt % biopolymers after only 6 h of feast (TAG:PHA ratio of 50:51; 0.423 CmmolBIOP/
CmmolS). Daily storage compound production was observed to be over 25% higher than the reached when
enrichment and accumulation stages were carried in separate operational units. Increasing the feast phase length
from 6 to 12 h (18 h cycle) negatively affected the DGL strategy performance and hence system storage capacity,
which was recovered after also extending the famine phase in the same proportion (24 h cycle). Besides, the
carbon influx during the feast phase was identified as a key operational parameter controlling storage compounds
production and, together with the C/N ratio, culture selection. The different cycle configurations tested
clearly modulated the total fungal abundances without no significant differences in the size of the bacterial
populations. Several PHA and TAG producers were found in the mixed culture although the PHA and TAG
productions were poorly associated with the increased relative abundances (RAs) of specific operational taxonomic
units (OTUs).Spanish Government (AEI, Spain) through the TREASURE project CTQ 2017-83225-C2-1-R
operative program FSE Galicia 2014-2020European Commissio
Rapid start-up and stable maintenance of the mainstream nitritation process based on the accumulation of free nitrous acid in a pilot-scale two-stage nitritation-anammox system
This work has been financed by the European Commission (EU) through the LIFE project ZERO WASTE WATER (LIFE19 ENV/ES/000631), the Waterworks 2014 Cofounded Call (Water JPI/Horizon) through the Pioneer_STP (PCIN-2015-022 MINECO (AEI)/ID 199 (UE)) and by the Spanish Government (AEI) through GRANDSEA (CTM2014-55397-JIN), TREASURE (CTQ2017-83225-C2-1-R) and ECOPOLYVER (PID2020-112550RB-C21 and PID2020-112550RB-C22) projects. Alba Pedrouso also acknowledges the Xunta de Galicia (Spain) for her post-doctoral fellowship (ED481B-2021-041). Authors from the USC belong to the Galician Competitive Research Group (GRC D431C-2021/37). Authors gratefully acknowledge the staff of the WWTP for their support.Two-stage partial nitritation (PN) and anammox (AMX) systems showed promising results for applying auto-trophic nitrogen removal under mainstream conditions. In this study, a pilot-scale (600 L per reactor) two-stage PN/AMX system was installed in a municipal wastewater treatment plant (WWTP) provided with a high-rate activated sludge (HRAS) system for organic carbon removal. The PN/AMX system was operated without tem-perature control (ranging from 11 to 28 degrees C) and was subjected to the same variations in wastewater charac-teristics as the WWTP (22 to 63 mg NH4+- N/L). The developed strategy is simple, does not require the addition of chemicals and is characterised by short start-up periods. The PN process was established by applying a high hydraulic load and maintained by in situ accumulated free nitrous acid (FNA) of 0.015-0.2 mg HNO2-N/L. Based on pH value, a controlled aeration strategy was applied to achieve the target nitrite to ammonium ratio in the effluent (1.1 g NO2--N/g NH4+-N) to feed the AMX reactor. Although NOB were not fully washed out from the system, nitrite accumulation remained (>99 %) stable with no evidence of NOB activity. In the AMX reactor, an overall nitrogen removal efficiency of 80 % was achieved. Regarding effluent quality, 12 +/- 3 mg TN/L was obtained, but 5 mg NO3--N/L was already in the HRAS effluent. The relative abundance of NOB showed a strong negative correlation with the FNA concentration, providing a good strategy for establishing PN under main-stream conditions.European Commission (EU) through the LIFE project ZERO WASTE WATER
LIFE19 ENV/ES/000631Waterworks 2014 Cofounded Call (Water JPI/Horizon) through the Pioneer_STP (MINECO (AEI)/(UE))
ED481B-2021-041Spanish Government (AEI)
199,
CTM2014-55397-JIN,
CTQ2017-83225-C2-1-R,
PID2020-112550RB-C21Xunta de Galicia
PID2020-112550RB-C22PCIN-2015-02
Flow Cytometric Investigation of Salinicola halophilus S28 Physiological Response Provides Solid Evidence for Its Uncommon and High Ability to Face Salt-Stress Conditions
In a previous work, some bacterial strains isolated from the Saline di Tarquinia marine
salterns (Viterbo, Italy) showed very unusual growth profiles in relation to temperature and salinity
variations when grown in solid media. In particular, Salinicola halophilus S28 showed optimal or
suboptimal growth in a very wide range of NaCl concentrations, suggesting a great coping ability
with salinity variations. These intriguing outcomes did not fit with the general Salinicola halophilus
description as a moderately halophilic species. Therefore, this study profiles the actual physiological
status of S28 cells subjected to different NaCl concentrations to provide evidence for the actual
coping ability of strain S28 with broad salinity variations. Flow cytometry was selected as the
evaluation method to study the physiological status of bacterial cells subjected to different salinity
levels, monitoring the strain response at different growth phases over 72 h. Strain S28 showed
maximal growth at 8% NaCl; however, it grew very well with no statistically significant differences at
all salinity conditions (4–24% NaCl). Flow cytometric results provided clear evidence of its actual and
strong ability to face increasing salinity, revealing a good physiological response up to 24% of NaCl. In
addition, strain S28 showed very similar cell physiological status at all salinity levels, as also indicated
by the flat growth profile revealed in the range of 4–24% NaCl. This is the first study regarding
the physiological response during the growth of halophilic bacteria under different conditions of
salinity via flow cytometry. This technique represents an effective tool for the investigation of the
physiological status of each cell, even if it is somehow underrated and underused by microbiologists
for this purpose
Impact on the microbial population during biological volatile fatty acid production from olive mill solid waste
This work was funded by the Spanish Ministry of Economy, Industry and Competitiveness (Ref. PID2020-116698RB-100). Dr. Antonio Serrano was funded by the Consejería de Transformación Económica, Industria, Conocimiento y Universidades (Junta de Andalucía - EMERGIA20_00114). Juan Cubero-Cardoso was funded by the Recualificación del Profesorado Universitario (Next Generation European Funds and Spanish University Ministry system).Supplementary material: Download Word document (34KB), 1-s2.0-S2352186423004054-mmc1Volatile fatty acids (VFAs) revalorisation from waste products are key in achieving industrial sustainability and circular economic goals. Hence, the objective of this work was to correlate the adaptability of the microbial community in olive mill solid waste (OMSW) anaerobic fermentation processes, to the production of VFAs under different pH conditions, i.e. under acidic (pH 4 &5), neutral (pH 6 & 7) and alkaline conditions (pH 9 & 10). At neutral conditions, anaerobic digestion exhibited minimal accumulation of VFAs, as they were primarily biotransformed to methane, where no significant changes in the microbial community were observed. At acidic conditions, a diverse profile of VFAs were present in the reactors, although the VFA production was limited to around 20 % of fed OMSW. Despite the low accumulation, the VFA profile at pH 5 was more complex than those at alkaline conditions, accounting propionic acid as the main VFA compound produced at pH 5 (60 % of the total VFAs). Acidic conditions entailed a shift in the microbial composition compared to the initial inoculum, although the reactors maintained similar diversity indices. At alkaline conditions, around 50 % of the fed OMSW was accumulated as VFAs, mainly as acetic acid. Overall, a lower diversity and higher dominance corresponded to a less diverse VFAs profile, such as the preponderance of acetic acid correlated with a microbial diversity decrease and the increased dominance of Tissirella.Spanish Ministry of Economy, Industry and Competitiveness (Ref. PID2020-116698RB-100)Junta de Andalucía - EMERGIA20_00114Recualificación del Profesorado Universitario (Next Generation European Funds and Spanish University Ministry system
Dynamics of PHA-Accumulating Bacterial Communities Fed with Lipid-Rich Liquid Effluents from Fish-Canning Industries
This research was supported by the Spanish Government (Spanish Ministry of Science and Innovation) through the TREASURE-MICROSALT (CTQ2017-83225-C2-2-R) and ECOPOLYVER-MACROPOLYVER (PID2020-112550RC22) projects.The biosynthesis of polyhydroxyalkanoates (PHAs) from industrial wastes by mixed
microbial cultures (MMCs) enriched in PHA-accumulating bacteria is a promising technology to
replace petroleum-based plastics. However, the populations’ dynamics in the PHA-accumulating
MMCs are not well known. Therefore, the main objective of this study was to address the shifts
in the size and structure of the bacterial communities in two lab-scale sequencing batch reactors
(SBRs) fed with fish-canning effluents and operated under non-saline (SBR-N, 0.5 g NaCl/L) or
saline (SBR-S, 10 g NaCl/L) conditions, by using a combination of quantitative PCR and Illumina
sequencing of bacterial 16S rRNA genes. A double growth limitation (DGL) strategy, in which
nitrogen availability was limited and uncoupled to carbon addition, strongly modulated the relative
abundances of the PHA-accumulating bacteria, leading to an increase in the accumulation of PHAs,
independently of the saline conditions (average 9.04 wt% and 11.69 wt%, maximum yields 22.03 wt%
and 26.33% SBR-N and SBR-S, respectively). On the other hand, no correlations were found among
the PHAs accumulation yields and the absolute abundances of total Bacteria, which decreased through
time in the SBR-N and did not present statistical differences in the SBR-S. Acinetobacter, Calothrix,
Dyella, Flavobacterium, Novosphingobium, Qipengyuania, and Tsukamurella were key PHA-accumulating
genera in both SBRs under the DGL strategy, which was revealed as a successful tool to obtain a
PHA-enriched MMC using fish-canning effluents.Spanish Government (Spanish Ministry of Science and Innovation) CTQ2017-83225-C2-2-R
PID2020-112550RC2
Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing
Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the
Peruvian Andes who continue growing it in small plots called chacras following ancestral
traditions. The abundance and structure of bacterial communities associated with the
roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the
main objective of this study was to describe the rhizospheric bacterial diversity of
amilaceous maize grown either in the presence or the absence of bur clover cultivated
in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding
to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions,
the second from the rhizosphere of maize-cultivated soils, and the third prepared from
rhizospheric soil of maize cultivated in intercropping with bur clover were examined using
pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total
of 26031 sequences were found that grouped into 5955 distinct operational taxonomic
units which distributed in 309 genera. The numbers of OTUs in the libraries from the
maize-cultivated soils were significantly higher than those found in the libraries from bulk
soil. One hundred ninety seven genera were found in the bulk soil library and 234 and
203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of
the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing
order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis
of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia,
Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas,
Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6
of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk
soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera
in the rhizosphere of maize intercropped with bur clover, and Gp4, Subdivision3 genera
incertae sedis of phylum Verrucomicrobia, Gp6 and Rhodoferax were the main genera
in the rhizosphere of maize plants. Taken together, our results suggest that bur clover
produces specific changes in rhizospheric bacterial diversity of amilaceous maize plants.Peer reviewe
Revealing the dissimilar structure of microbial communities in different WWTPs that treat fish-canning wastewater with different NaCl content
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. This research was supported by the Spanish Government (Spanish Ministry of Science and Innovation) through TREASURE-TECHNOSALT (CTQ2017-83225-C2-1-R) and TREASURE-MICROSALT (CTQ2017-83225-C2-2-R) projects.
The authors Alba Roibas-Rozas and Anuska Mosquera-Corral belong to the Galician Competitive Research Group GRC-ED431C 2017-29 and to the CRETUS Strategic Partnership (ED431E 2018/01) . All these programmes are co-funded by FEDER (UE) . Funding for open access charge: Universidad de Granada/CBUA.Studies that characterize the microbial communities in wastewater treatment plants (WWTPs) are numerous, yet
similar studies in industrial WWTPs treating fish-canning effluents are limited. The microbial communities in
samples of 4 fish-canning WWTPs that operated under different NaCl concentrations were investigated by qPCR
and partial 16S rRNA gene Illumina sequencing. The absolute abundances of key microbial populations (Total
Bacteria, Archaea and Fungi, ammonium oxidizing bacteria (AOB), Mycolata, Candidatus Microthrix, Ca. Accumulibacter
and Ca. Competibacter) presented statistical differences among the WWTPs. The NaCl concentration
negatively affected the absolute abundance of Bacteria and Fungi, filamentous, and phosphate (PAO) and
glycogen (GAO) accumulating bacteria, while AOB and Ca. Microthrix populations were statistically higher in
the WWTP with higher NaCl contents. On the other hand, the main bacterial operational taxonomic units (OTUs)
were classified as members of Kouleothrix (Chloroflexia, Chloroflexi) and Tetrasphaera (Actinomycetia, Actinobacteria),
family Beijerinckiaceae (Alphaproteobacteria, Proteobacteria), order Betaproteobacteriales (Gammaproteobacteria,
Proteobacteria), Sphingobacteriales (Sphingobacteriia, Bacteroidetes) and Frankiales (Actinobacteria,
Actinobacteria), class Anaerolineae (Chloroflexi), phylum Chloroflexi and Bacteria_unclassified. The structure of the
bacterial community was highly dissimilar among the 4 WWTPs, as the identities of the dominant OTUs differed
significantly among them. Therefore, the individual characteristics of the different WWTPs, mainly NaCl concentration,
were responsible for the narrow assemblage of the bacterial communities. Different OTUs belonging
to the phyla Actinobacteria, Bacteroidetes, Chloroflexi, Gemmatimonadetes and Proteobacteria were revealed as salttolerant.
Taking into account these results, NaCl content was an important driver of the abundance of microbial
populations and the bacterial community structure in the analysed industrial facilities.Spanish Government (Spanish Ministry of Science and Innovation) CTQ2017-83225-C2-1-R
CTQ2017-83225-C2-2-REuropean CommissionGalician Competitive Research Group GRC-ED431C 2017-29CRETUS Strategic Partnership ED431E 2018/0
Structure of fungal communities in sequencing batch reactors operated at different salinities for the selection of triacylglyceride-producers from a fish-canning lipid-rich waste stream
Oleaginous fungi natively accumulate large amounts of triacylglycerides (TAG), widely used as precursors for
sustainable biodiesel production. However, little attention has been paid to the diversity and roles of fungal
mixed microbial cultures (MMCs) in sequencing batch reactors (SBR). In this study, a lipid-rich stream produced
in the fish-canning industry was used as a substrate in two laboratory-scale SBRs operated under the feast/famine
(F/F) regime to enrich microorganisms with high TAG-storage ability, under two different concentrations of NaCl
(SBR-N: 0.5 g/L; SBR-S: 10 g/L). The size of the fungal community in the enriched activated sludge (EAS) was
analyzed using 18S rRNA-based qPCR, and the fungal community structure was determined by Illumina
sequencing. The different selective pressures (feeding strategy and control of pH) implemented in the enrichment
SBRs throughout operation increased the abundance of total fungi. In general, there was an enrichment of genera
previously identified as TAG-accumulating fungi (Apiotrichum, Candida, Cutaneotrichosporon, Geotrichum,
Haglerozyma, Metarhizium, Mortierella, Saccharomycopsis, and Yarrowia) in both SBRs. However, the observed
increase of their relative abundances throughout operation was not significantly linked to a higher TAG
accumulation.Spanish Government CTQ2017 - 83225-C2 - 1- R
CTQ2017 - 83225-C2 - 2-R
PID-2020 - 112550RB-C2
Effects of nitrate contamination and seasonal variation on the denitrification and greenhouse gas production in La Rocina stream (Doñana National Park, SW Spain)
Climatic influence (global warming and decreased rainfall) could lead to an increase in the ecological
and toxicological effects of the pollution in aquatic ecosystems, especially contamination from agricultural
nitrate (NO3
−) fertilizers. Physicochemical properties of the surface waters and sediments of four
selected sites varying in NO3
− concentration along La Rocina Stream, which feeds Marisma del Rocio in
Do˜nana National Park (South West, Spain), were studied. Electrical conductivity, pH, content in macro
and microelements, total organic carbon and nitrogen, and dissolved carbon and nitrogen were affected
by each sampling site and sampling time. Contaminant NO3
− in surface water at the site with the highest
NO3
− concentration (ranged in 61.6–106.6mgL−1) was of inorganic origin, most probably from chemical
fertilizers, as determined chemically (90% of the total dissolved nitrogen from NO3
−) and by isotopic analysis
of ı15N-NO3
−. Changes in seasonal weather conditions and hydrological effects at the sampling sites
were also responsible for variations in some biological activities (dehydrogenase, -glucosidase, arylsulphatase,
acid phosphatase and urease) in sediments, as well as in the production of the greenhouse gases
CO2, CH4 and N2O. Both organic matter and NO3
− contents influenced rates of gas production. Increased
NO3
− concentration also resulted in enhanced levels of potential denitrification measured as N2O production.
The denitrification process was affected by NO3
− contamination and the rainfall regimen, increasing
the greenhouse gases emissions (CO2, CH4 and especially N2O) during the driest season in all sampling
sites studied.This work was supported by grants CGL2006-06870 and
CTM2009-1473-C02-02 from Ministerio de Ciencia e Innovación
(Spain) and RNM-4746 from Consejería de Innovación, Ciencia y
Empresa de la Junta de Andalucía (Spain), all of them co-financed by
the European Regional Development Fund (ERDF). Support of Junta
de Andalucía to Research Group BIO-275 is also acknowledged. D.
David Correa thanks Ministerio de Educación for predoctoral grant
AP2007-03967.Peer reviewe
Lacasa de alto potencial redox funcional en sangre mediante evolución dirigida método de obtención y sus aplicaciones
La presente invención describe una lacasa de alto
potencial redox obtenida mediante evolución
molecular dirigida que es activa en condiciones
electrofisiológicas, que resiste elevadas
concentraciones de haluros, que tiene una actividad
significativa a pHs neutros/alcalinos y que es activa
en sangre y plasma humano. La presente invención
se refiere a la secuencia aminoacídica de dicha
lacasa, a la secuencia nucleotídica que codifica para
dicha lacasa y células que permiten su obtención. La
lacasa de la invención presenta aplicaciones en
diversos sectores: nano-biotecnología, biomedicina,
procesos de biorremediación, industria papelera y
química fina.Peer reviewedConsejop Superior de Investigaciones CientíficasA1 Solicitud de patente con informe sobre el estado de la técnic
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