Effects of amylose and resistant starch on starch digestibility of rice flours and starches

Amylose and resistant starch (RS) content in rice flours and starches were manipulated by adding high amylose and high RS maize starch. The maize starches were added to rice flours and rice starches at the levels of 10-50% w/w, resulting in the increase of amylose from approximately 30-56 and RS from 8 - 33 g/100 g dry sample. Physicochemical properties and starch digestibility of the mixtures, both flour and starch mixtures, were investigated. Differential scanning calorimetry (DSC) results showed that the addition of high amylose high RS maize starch at the levels in this study did not significantly (p > 0.05) alter gelatinization temperatures. Texture analysis as exhibited by hardness and adhesiveness of the mixture gels found inconsistent results. The key benefit of adding high amylose and high RS maize starch was that it can alter starch digestion rates and consequently lower estimated glycaemic indices (GIs) in both rice flour and starch mixtures

Can white-rot fungi be a real wastewater treatment alternative for organic micropollutants removal? A review

Micropollutants are a diverse group of compounds that are detected at trace concentrations and may have a negative effect on the environment and/or human health. Most of them are unregulated contaminants, although they have raised a concern in the scientific and global community and future regulation might be written in the near future. Several approaches have been tested to remove micropollutants from wastewater streams. In this manuscript, a focus is placed in reactor biological treatments that use white-rot fungi. A critical review of white-rot fungal-based technologies for micropollutant removal from wastewater has been conducted, several capabilities and limitations of such approaches have been identified and a range of solutions to overcome most of the limitations have been reviewed and/or proposed. Overall, this review argues that white-rot fungal reactors could be an efficient technology to remove micropollutants from specific wastewater streams

Physicochemical properties and starch digestibility of Scirpus grossus flour and starch

Flour and starch isolated from the tubers of Scirpus grossus were investigated for their physicochemical properties and starch digestibility. The flour was extracted using two different processes namely peeled and unpeeled processes. Proximate analysis revealed that the flours from both processes contain considerably high total starch, more than 80%, which indicate their potential use as starchy foods. The amylose content of the flours and starches ranged from 29 to 32%. Starch granules of S. grossus were oval in shape with smooth surface and small diameters ranging from 6 to 15 μm. All samples exhibited high swelling pasting behaviors with pasting temperatures ranging from 78 to 79 °C, indicating the strong bonding forces within the granule interiors. Differential scanning calorimetry (DSC) results suggested that the samples gelatinized at temperatures ranging from 71 to 81 °C. In vitro starch digestion assay found that all samples provided the estimated glycaemic index (GI) values of approximately 55 or les

Continuous treatment of non-sterile hospital wastewater by Trametes versicolor : how to increase fungal viability by means of operational strategies and pretreatments

Hospital wastewaters have a high load of pharmaceutical active compounds (PhACs). Fungal treatments could be appropriate for source treatment of such effluents but the transition to non-sterile conditions proved to be difficult due to competition with indigenous microorganisms, resulting in very short-duration operations. In this article, coagulation-flocculation and UV-radiation processes were studied as pretreatments to a fungal reactor treating non-sterile hospital wastewater in sequential batch operation and continuous operation modes. The influent was spiked with ibuprofen and ketoprofen, and both compounds were successfully degraded by over 80%. UV pretreatment did not extent the fungal activity after coagulation-flocculation measured as laccase production and pellet integrity. Sequential batch operation did not reduce bacteria competition during fungal treatment. The best strategy was the addition of a coagulation-flocculation pretreatment to a continuous reactor, which led to an operation of 28days without biomass renovation

Degradation of selected agrochemicals by the white rot fungus Trametes versicolor

Use of agrochemicals is a worldwide practice that exerts an important effect on the environment; therefore the search of approaches for the elimination of such pollutants should be encouraged. The degradation of the insecticides imiprothrin (IP) and cypermethrin (CP), the insecticide/nematicide carbofuran (CBF) and the antibiotic of agricultural use oxytetracycline (OTC) were assayed with the white rot fungus Trametes versicolor. Experiments with fungal pellets demonstrated extensive degradation of the four tested agrochemicals, at rates that followed the pattern IP > OTC > CP > CBF. In vitro assays with laccase-mediator systems showed that this extracellular enzyme participates in the transformation of IP but not in the cases of CBF and OTC. On the other hand, in vivo studies with inhibitors of cytochrome P450 revealed that this intracellular system plays an important role in the degradation of IP, OTC and CBF, but not for CP. The compounds 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA) and 3-phenoxybenzoic acid (PBA) were detected as transformation products of CP, as a result of the breakdown of the molecule. Meanwhile, 3-hydroxycarbofuran was detected as a transformation product of CBF; this metabolite tended to accumulate during the process, nonetheless, the toxicity of the system was effectively reduced. Simultaneous degradation of CBF and OTC showed a reduction in toxicity; similarly, when successive additions of OTC were done during the slower degradation of CBF, the fungal pellets were able to degrade both compounds. The simultaneous degradation of the four compounds successfully took place with minimal inhibition of fungal activity and resulted in the reduction of the global toxicity, thus supporting the potential use of T. versicolor for the treatment of diverse agrochemicals

Process development for hospital wastewater treatment by Trametes versicolor

Els microcontaminants són un ampli grup de compostos orgànics que s'han detectat a la majoria de compartiments del medi ambient. La seva concentració ambiental està compresa entre pocs ng·L-1 fins a μg·L-1, però es mantenen biològicament actius fins i tot a concentracions tan baixes, poden ser acumulats a través de la cadena tròfica i suposen una amenaça per al medi ambient, la fauna i la salut humana. D'entre els microcontaminants, els fàrmacs (PhACs) generen una especial preocupació. És acceptat que la principal font d'entrada de fàrmacs al medi ambient és via efluents de les estacions depuradores d'aigües residuals (WWTP), on els mecanismes convencionals de llots activats no són suficients per degradar-ne la majoria. En resposta a aquestes preocupacions, la comunitat científica ha destinat molta recerca a mètodes per a la degradació, transformació i/o eliminació de microcontaminants d'aigües residuals d'hospital, on els fàrmacs estan presents a major concentració. D'entre els tractaments possibles, els fongs de podridura blanca (WRF) es presenten com una possibilitat atractiva gràcies al seu baix cost en comparació amb tractaments físics i químics i la seva capacitat de transformar la majoria de compostos gràcies a la seva versàtil maquinària enzimàtica. Els WRF han estat estudiats per a la degradació de fàrmacs en aigües residuals, però la contaminació per microorganismes presents a l'aigua residual ha produït que les operacions en reactor fossin molt curtes. Aquesta tesi aborda aquest problema i proposa diverses estratègies per allargar el tractament. També serveix com a prova que una operació prolongada amb WRF tractant aigua residual d'hospital no estèril és possible. Primer de tot, diversos reactors de llit fluïditzat per polsos d'aire es van operar per estudiar l'efecte que tenien l'addició d'un pre-tractament de coagulació-floculació, l'addició d'un pre-tractament amb llum UV i l'efecte de l'operació com a batch seqüencial (SBR) i en continu en la llargada del tractament. La millor alternativa va ser un reactor en continu amb un pre-tractament de coagulació-floculació. Aquest tren de tractament va ser evaluat en un tractament d'aigua residual d'hospital no dopada amb renovació parcial de la biomassa, i va permetre una operació de dos mesos de durada. A més, diverses variables de procés, a saber, mida del pèl·let, aeració i la ràtio carboni-nitrogen es van estudiar i els valors que van suposar una operació més llarga van ser seleccionats. Aquests estudis previs van permetre per primera vegada una operació prolongada d'un reactor fúngic de llit fluïditzat tractant aigua residual d'hospital no estèril. Aquesta tesi també remarca la importància dels processos de conjugació i desconjugació. Les tècniques analítiques actuals no solen detectar els microcontaminants conjugats, i això impedeix una precisa mesura de la concentració del contaminant estudiat. Per tant, s'haurien de destinar esforços a l'anàlisi de les formes conjugades de compostos. Si s'aconsegueix, podria significar un gran avenç que faciliti l'estudi de l'eliminació de microcontaminants en aigües reals. Les anàlisis de biologia molecular com gel d'electroforesi en gradient desnaturalitzant (DGGE), seqüenciació d'ADN i PCR quantitativa (qPCR) es van aplicar els experiments no dopats per donar informació sobre les comunitats microbiològiques formades durant els tractaments en reactor i per confirmar la presència de T. versicolor durant l'operació. Els resultats suggereixen que el fong es mantenia actiu fins i tot quan l'activitat de l'enzim lacasa no es detectava.Micropollutants are a wide group of organic compounds that are detected at most compartments of the environment. Their environmental concentration is usually in the range of few ng·L-1 to μg·L-1, but remain biologically active even at such low concentrations, may be accumulated through the food chain and pose a threat to the environment, fauna and human health. Among micropollutants, pharmaceutical active compounds (PhACs) are of special concern. It is accepted that the main sources of PhACs to the environment are effluents from wastewater treatment plants (WWTPs), where conventional activated sludge processes are not able to degrade most of them. Answering to these concerns, the scientific community has devoted extensive research into mechanisms to degrade, transform and /or remove micropollutants from hospital wastewater, where PhACs are present at higher concentrations. Among the possible treatments, white-rot fungi (WRF) are regarded as a cost-effective possibility due to their relatively low cost in comparison with physical and chemical treatments and their capacity to transform most of the compounds thanks to their versatile enzymatic machinery. WRF have been studied for the removal of pharmaceuticals in wastewater, but contamination by wastewater-native microorganisms has produced very short-term reactor operations. The present thesis tackles this problem and proposes several strategies to lengthen the fungal treatment. It also serves as proof of concept of a long-term white-rot fungal operation treating non-sterile real hospital wastewater. First of all, several air-pulsed fluidized bed bioreactors were set up in order to study the effect of the addition of a coagulation-flocculation pretreatment, of the addition of a UV pretreatment and the effect of operating the reactors as a sequencing batch reactor (SBR) or in a continuous fashion on the length of operation. The chosen alternative was a continuous reactor with a coagulation-floculation pretreatment. This treatment train was then evaluated in a non-spiked hospital wastewater treatment with partial biomass restoration, leading to a two-month operation. Additionally, several process variables, namely, pellet size, aeration and carbon-to-nitrogen ratio were studied and the values that led to a longer operation were selected. Those previous studies enabled for the first time a long-term operation of a fungal fluidized bed bioreactor treating real non-sterile wastewater. The importance of conjugation and deconjugation processes is highlighted in this thesis. Conjugated microcontaminants are not usually detected by the current analytical techniques, thus undervaluing the concentration of the pollutant studied. Therefore, an effort should be made to analyze conjugated forms of compounds. If successful, it could be a breakthrough that greatly facilitates the study of removal of micropollutants in real wastewater. Molecular biology analyses such as denaturing gradient gel electrophoresis (DGGE), DNA sequencing and real-time PCR (qPCR) were performed in the non-spiked experiments to give insight on the microbiological communities arisen during the reactor treatment and to confirm the presence of T. versicolor throughout the operation. Results suggested that the fungus was active even when no laccase activity was detected

Influence of process variables in a continuous treatment of non-sterile hospital wastewater by Trametes versicolor and novel method for inoculum production

Micropollutants such as pharmaceutical active compounds, present at high concentration in hospital wastewater (HWW), pose both environmental and human health challenges. Fungal reactors can effectively remove such contaminants and produce non-toxic effluents, but their ability to operate for a long period of time is yet to be demonstrated in real hospital wastewater. Several process variables need to be studied beforehand. Here, variables: pellet size, aeration and carbon-to-nitrogen ratio are studied in continuous operations with real HWW. Moreover, a novel strategy for inoculum production that could reduce economical and operational costs is proposed and tested. Optimum pellet size was found to be 2 mm and an aeration of 0.8 L min−1 was needed to maintain fungal viability. The carbon-to-nitrogen ratio of 7.5 was selected and the pellet production time was reduced from 6 to 3 days. The novel low-cost inoculum preparation produced pellets with the same characteristics as the traditionally prepared ones. © 2018 Elsevier LtdThis work has been funded by the Spanish Ministry of Economy and Competitiveness (project CTM 2013–48545-C2-1-R ) and partly supported by the Generalitat de Catalunya (Consolidated Research Group 2014-SGR-0476 ). The Department of Chemical, Biological and Environmental Engineering of Universitat Autònoma de Barcelona (UAB) is member of the Xarxa de Referència en Biotecnologia de la Generalitat de Catalunya. J.A. Mir-Tutusaus acknowledges the predoctoral grant from UAB . Appendix APeer reviewe

Effects of amylose and resistant starch on starch digestibility of rice flours and starches

Amylose and resistant starch (RS) content in rice flours and starches were manipulated by adding high amylose and high RS maize starch. The maize starches were added to rice flours and rice starches at the levels of 10-50% w/w, resulting in the increase of amylose from approximately 30-56 and RS from 8 - 33 g/100 g dry sample. Physicochemical properties and starch digestibility of the mixtures, both flour and starch mixtures, were investigated. Differential scanning calorimetry (DSC) results showed that the addition of high amylose high RS maize starch at the levels in this study did not significantly (p > 0.05) alter gelatinization temperatures. Texture analysis as exhibited by hardness and adhesiveness of the mixture gels found inconsistent results. The key benefit of adding high amylose and high RS maize starch was that it can alter starch digestion rates and consequently lower estimated glycaemic indices (GIs) in both rice flour and starch mixtures

Process development for hospital wastewater treatment by Trametes versicolor /

Bibliografia.Els microcontaminants són un ampli grup de compostos orgànics que s'han detectat a la majoria de compartiments del medi ambient. La seva concentració ambiental està compresa entre pocs ng·L-1 fins a μg·L-1, però es mantenen biològicament actius fins i tot a concentracions tan baixes, poden ser acumulats a través de la cadena tròfica i suposen una amenaça per al medi ambient, la fauna i la salut humana. D'entre els microcontaminants, els fàrmacs (PhACs) generen una especial preocupació. És acceptat que la principal font d'entrada de fàrmacs al medi ambient és via efluents de les estacions depuradores d'aigües residuals (WWTP), on els mecanismes convencionals de llots activats no són suficients per degradar-ne la majoria. En resposta a aquestes preocupacions, la comunitat científica ha destinat molta recerca a mètodes per a la degradació, transformació i/o eliminació de microcontaminants d'aigües residuals d'hospital, on els fàrmacs estan presents a major concentració. D'entre els tractaments possibles, els fongs de podridura blanca (WRF) es presenten com una possibilitat atractiva gràcies al seu baix cost en comparació amb tractaments físics i químics i la seva capacitat de transformar la majoria de compostos gràcies a la seva versàtil maquinària enzimàtica. Els WRF han estat estudiats per a la degradació de fàrmacs en aigües residuals, però la contaminació per microorganismes presents a l'aigua residual ha produït que les operacions en reactor fossin molt curtes. Aquesta tesi aborda aquest problema i proposa diverses estratègies per allargar el tractament. També serveix com a prova que una operació prolongada amb WRF tractant aigua residual d'hospital no estèril és possible. Primer de tot, diversos reactors de llit fluïditzat per polsos d'aire es van operar per estudiar l'efecte que tenien l'addició d'un pre-tractament de coagulació-floculació, l'addició d'un pre-tractament amb llum UV i l'efecte de l'operació com a batch seqüencial (SBR) i en continu en la llargada del tractament. La millor alternativa va ser un reactor en continu amb un pre-tractament de coagulació-floculació. Aquest tren de tractament va ser evaluat en un tractament d'aigua residual d'hospital no dopada amb renovació parcial de la biomassa, i va permetre una operació de dos mesos de durada. A més, diverses variables de procés, a saber, mida del pèl·let, aeració i la ràtio carboni-nitrogen es van estudiar i els valors que van suposar una operació més llarga van ser seleccionats. Aquests estudis previs van permetre per primera vegada una operació prolongada d'un reactor fúngic de llit fluïditzat tractant aigua residual d'hospital no estèril. Aquesta tesi també remarca la importància dels processos de conjugació i desconjugació. Les tècniques analítiques actuals no solen detectar els microcontaminants conjugats, i això impedeix una precisa mesura de la concentració del contaminant estudiat. Per tant, s'haurien de destinar esforços a l'anàlisi de les formes conjugades de compostos. Si s'aconsegueix, podria significar un gran avenç que faciliti l'estudi de l'eliminació de microcontaminants en aigües reals. Les anàlisis de biologia molecular com gel d'electroforesi en gradient desnaturalitzant (DGGE), seqüenciació d'ADN i PCR quantitativa (qPCR) es van aplicar els experiments no dopats per donar informació sobre les comunitats microbiològiques formades durant els tractaments en reactor i per confirmar la presència de T. versicolor durant l'operació. Els resultats suggereixen que el fong es mantenia actiu fins i tot quan l'activitat de l'enzim lacasa no es detectava.Micropollutants are a wide group of organic compounds that are detected at most compartments of the environment. Their environmental concentration is usually in the range of few ng·L-1 to μg·L-1, but remain biologically active even at such low concentrations, may be accumulated through the food chain and pose a threat to the environment, fauna and human health. Among micropollutants, pharmaceutical active compounds (PhACs) are of special concern. It is accepted that the main sources of PhACs to the environment are effluents from wastewater treatment plants (WWTPs), where conventional activated sludge processes are not able to degrade most of them. Answering to these concerns, the scientific community has devoted extensive research into mechanisms to degrade, transform and /or remove micropollutants from hospital wastewater, where PhACs are present at higher concentrations. Among the possible treatments, white-rot fungi (WRF) are regarded as a cost-effective possibility due to their relatively low cost in comparison with physical and chemical treatments and their capacity to transform most of the compounds thanks to their versatile enzymatic machinery. WRF have been studied for the removal of pharmaceuticals in wastewater, but contamination by wastewater-native microorganisms has produced very short-term reactor operations. The present thesis tackles this problem and proposes several strategies to lengthen the fungal treatment. It also serves as proof of concept of a long-term white-rot fungal operation treating non-sterile real hospital wastewater. First of all, several air-pulsed fluidized bed bioreactors were set up in order to study the effect of the addition of a coagulation-flocculation pretreatment, of the addition of a UV pretreatment and the effect of operating the reactors as a sequencing batch reactor (SBR) or in a continuous fashion on the length of operation. The chosen alternative was a continuous reactor with a coagulation-floculation pretreatment. This treatment train was then evaluated in a non-spiked hospital wastewater treatment with partial biomass restoration, leading to a two-month operation. Additionally, several process variables, namely, pellet size, aeration and carbon-to-nitrogen ratio were studied and the values that led to a longer operation were selected. Those previous studies enabled for the first time a long-term operation of a fungal fluidized bed bioreactor treating real non-sterile wastewater. The importance of conjugation and deconjugation processes is highlighted in this thesis. Conjugated microcontaminants are not usually detected by the current analytical techniques, thus undervaluing the concentration of the pollutant studied. Therefore, an effort should be made to analyze conjugated forms of compounds. If successful, it could be a breakthrough that greatly facilitates the study of removal of micropollutants in real wastewater. Molecular biology analyses such as denaturing gradient gel electrophoresis (DGGE), DNA sequencing and real-time PCR (qPCR) were performed in the non-spiked experiments to give insight on the microbiological communities arisen during the reactor treatment and to confirm the presence of T. versicolor throughout the operation. Results suggested that the fungus was active even when no laccase activity was detected