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1.
Microb Cell Fact ; 17(1): 83, 2018 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-29855369

RESUMEN

BACKGROUND: Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils. RESULTS: From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls. CONCLUSIONS: Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.


Asunto(s)
Bacterias/química , Suelo/química , Agua/química , Humedad
2.
Microb Cell Fact ; 16(1): 127, 2017 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-28738864

RESUMEN

BACKGROUND: Microbial reductive dechlorination of polychlorinated biphenyls (PCBs) plays a major role in detoxifying anoxic contaminated freshwater and marine sediments from PCBs. Known members of the phylum Chloroflexi are typically responsible for this activity in freshwater sediments, whereas less is known about the microorganisms responsible for this activity in marine sediments. PCB-respiring activities were detected in PCB-impacted marine sediments of the Venice Lagoon. The aim of this work was to identify the indigenous organohalide-respiring microorganisms in such environments and assess their dechlorination specificity against spiked Aroclor™ 1254 PCBs under laboratory conditions resembling the in situ biogeochemistry. RESULTS: High PCB dechlorination activities (from 150 ± 7 to 380 ± 44 µmol of chlorine removed kg-1 week-1) were detected in three out of six sediments sampled from different locations of the lagoon. An uncultured non-Dehalococcoides phylotype of the class Dehalococcoidia closely related to Dehalobium chlorocoercia DF-1, namely phylotype VLD-1, was detected and enriched up to 109 16S rRNA gene copies per gram of sediment where dechlorination activities were higher and 25-4/24-4 and 25-2/24-2/4-4 chlorobiphenyls (CB) accumulated as the main tri-/dichlorinated products. Conversely, a different phylotype closely related to the SF1/m-1 clade, namely VLD-2, also enriched highly where lower dechlorination activity and the accumulation of 25-3 CB as main tri-chlorinated product occurred, albeit in the simultaneous presence of VLD-1. Both phylotypes showed growth yields higher or comparable to known organohalide respirers and neither phylotypes enriched in sediment cultures not exhibiting dechlorination. CONCLUSIONS: These findings confirm the presence of different PCB-respiring microorganisms in the indigenous microbial communities of Venice Lagoon sediments and relate two non-Dehalococcoides phylotypes of the class Dehalococcoidia to different PCB dechlorination rates and specificities.


Asunto(s)
Cloro/metabolismo , Chloroflexi/metabolismo , Sedimentos Geológicos/microbiología , Bifenilos Policlorados/metabolismo , Biodegradación Ambiental , Cloro/química , Chloroflexi/clasificación , Chloroflexi/genética , Filogenia , Bifenilos Policlorados/química , ARN Ribosómico 16S/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
3.
Microb Cell Fact ; 16(1): 186, 2017 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-29096660

RESUMEN

BACKGROUND: The application of chemical dispersants as a response to marine oil spills is raising concerns related to their potential toxicity also towards microbes involved in oil biodegradation. Hence, oil spills occurring under marine environments necessitate the application of biodispersants that are highly active, stable and effective under marine environment context. Biosurfactants from marine bacteria could be good candidates for the development of biodispersant formulations effective in marine environment. This study aimed at establishing a collection of marine bacteria able to produce surface-active compounds and evaluating the activity and stability of the produced compounds under conditions mimicking those found under marine environment context. RESULTS: A total of 43 different isolates were obtained from harbor sediments. Twenty-six of them produced mainly bioemulsifiers when glucose was used as carbon source and 16 were biosurfactant/bioemulsifiers producers after growth in the presence of soybean oil. Sequencing of 16S rRNA gene classified most isolates into the genus Marinobacter. The produced emulsions were shown to be stable up to 30 months monitoring period, in the presence of 300 g/l NaCl, at 4 °C and after high temperature treatment (120 °C for 20 min). The partially purified compounds obtained after growth on soybean oil-based media exhibited low toxicity towards V. fischeri and high capability to disperse crude oil on synthetic marine water. CONCLUSIONS: To the best of our knowledge, stability characterization of bioemulsifiers/biosurfactants from the non-pathogenic marine bacterium Marinobacter has not been previously reported. The produced compounds were shown to have potential for different applications including the environmental sector. Indeed, their high stability in the presence of high salt concentration and low temperature, conditions characterizing the marine environment, the capability to disperse crude oil and the low ecotoxicity makes them interesting for the development of biodispersants to be used in combatting marine oil spills.


Asunto(s)
Sedimentos Geológicos/microbiología , Marinobacter/metabolismo , Petróleo/metabolismo , Tensoactivos/metabolismo , Biodegradación Ambiental , Marinobacter/genética , Marinobacter/crecimiento & desarrollo , Marinobacter/aislamiento & purificación , Contaminación por Petróleo , ARN Ribosómico 16S/química , ARN Ribosómico 16S/aislamiento & purificación , ARN Ribosómico 16S/metabolismo , Análisis de Secuencia de ADN , Aceite de Soja/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Tensoactivos/química
4.
Crit Rev Biotechnol ; 36(1): 175-89, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25373788

RESUMEN

Availability of bio-based chemicals, materials and energy at reasonable cost will be one of the forthcoming issues for the EU economy. In particular, the development of technologies making use of alternative resources to fossil fuels is encouraged by the current European research and innovation strategy to face the societal challenge of natural resource scarcity, fossil resource dependence and sustainable economic growth. In this respect, second- generation biorefineries, i.e. biorefineries fed with biowastes, appear to be good candidates to substitute and replace the present downstream processing scheme. Contrary to first-generation biorefineries, which make use of dedicated crops or primary cultivations to achieve such a goal, the former employ agricultural, industrial, zootechnical, fishery and forestry biowastes as the main feedstock. This leaves aside any ethical and social issue generated by first-generation approaches, and concomitantly prevents environmental and economical issues associated with the disposal of the aforementioned leftovers. Unfortunately, to date, a comprehensive and updated mapping of the availability and potential use of bioresources for second-generation biorefineries in Europe is missing. This is a lack that severely limits R&D and industrial applications in the sector. On the other hand, attempts at valorizing the most diverse biowastes dates back to the nineteenth century and plenty of information in the literature on their sustainable exploitation is available. However, the large majority of these investigations have been focused on single fractions of biowastes or single steps of biowaste processing, preventing considerations on an integrated and modular (cascade) approach for the whole valorization of organic leftovers. This review aims at addressing these issues by gathering recent data on (a) some of the main high-impact biowastes located in Europe and in particular in its Southern part, and (b) the bio-based chemicals, materials and fuels that can be produced from such residues. In particular, we focused on those key compounds referred to as "chemical platforms", which have been indicated as fundamental to generate the large majority of the industrially relevant goods to date.


Asunto(s)
Agricultura , Biocombustibles , Residuos Industriales , Europa (Continente) , Industrias , Solanum lycopersicum/química , Olea/química , Vitis/química
5.
Appl Microbiol Biotechnol ; 99(19): 7907-13, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26272092

RESUMEN

In the last decade, attention to extreme environments has increased because of interests to isolate previously unknown extremophilic microorganisms in pure culture and to profile their metabolites. Microorganisms that live in extreme environments produce extremozymes and extremolytes that have the potential to be valuable resources for the development of a bio-based economy through their application to white, red, and grey biotechnologies. Here, we provide an overview of extremophile ecology, and we review the most recent applications of microbial extremophiles and the extremozymes and extremolytes they produce to biotechnology.


Asunto(s)
Bacterias/enzimología , Proteínas Bacterianas/química , Enzimas/química , Bacterias/química , Bacterias/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biotecnología , Estabilidad de Enzimas , Enzimas/genética , Enzimas/metabolismo
6.
New Phytol ; 204(4): 890-900, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25103459

RESUMEN

In anaerobiosis, the microalga Chlamydomonas reinhardtii is able to produce H2 gas. Electrons mainly derive from mobilization of internal reserves or from water through biophotolysis. However, the exact mechanisms triggering this process are still unclear. Our hypothesis was that, once a proper redox state has been achieved, H2 production is eventually observed. To avoid nutrient depletion, which would result in enhanced fermentative pathways, we aimed to induce long-lasting H2 production solely through a photosynthesis : respiration equilibrium. Thus, growing cells were incubated in Tris Acetate Phosphate (TAP) medium under low light and high chlorophyll content. After a 250-h acclimation phase, a 350-h H2 production phase was observed. The light-to-H2 conversion efficiency was comparable to that given in some reports operating under sulphur starvation. Electron sources were found to be water, through biophotolysis, and proteins, particularly through photofermentation. Nonetheless, a substantial contribution from acetate could not be ruled out. In addition, photosystem II (PSII) inhibition by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) showed that it actively contributed to maintaining a redox balance during cell acclimation. In appropriate conditions, PSII may represent the major source of reducing power to feed the H2 evolution process, by inducing and maintaining an ideal excess of reducing power.


Asunto(s)
Aclimatación , Chlamydomonas reinhardtii/fisiología , Hidrógeno/metabolismo , Anaerobiosis , Hipoxia de la Célula , Respiración de la Célula , Chlamydomonas reinhardtii/efectos de los fármacos , Chlamydomonas reinhardtii/metabolismo , Clorofila/metabolismo , Diurona/farmacología , Fermentación , Hidrogenasas/metabolismo , Luz , Fotólisis , Complejo de Proteína del Fotosistema II/antagonistas & inhibidores , Complejo de Proteína del Fotosistema II/metabolismo
7.
Biodegradation ; 25(3): 337-50, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24096531

RESUMEN

A procedure for the design of an aerobic cometabolic process for the on-site degradation of chlorinated solvents in a packed bed reactor was developed using groundwater from an aquifer contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA). The work led to the selection of butane among five tested growth substrates, and to the development and characterization from the site's indigenous biomass of a suspended-cell consortium capable to degrade TCE (first order constant: 96 L gprotein(-1) day(-1) at 30 °C and 4.3 L gprotein(-1) day(-1) at 15 °C) with a 90 % mineralization of the organic chlorine. The consortium immobilization had strong effects on the butane and TCE degradation rates. The microbial community structure was slightly changed by a temperature shift from 30 to 15 °C, but remarkably affected by biomass adhesion. Given the higher TCE normalized degradation rate (0.59 day(-1) at 15 °C) and attached biomass concentration (0.13 gprotein Lbioreactor(-1) at 15 °C) attained, the porous ceramic carrier Biomax was selected as the best option for the packed bed reactor process. The low TeCA degradation rate exhibited by the developed consortium suggested the inclusion of a chemical pre-treatment based on the TeCA to TCE conversion via ß-elimination, a very fast reaction at alkaline pH. To the best of the authors' knowledge, this represents the first attempt to develop a procedure for the development of a packed bed reactor process for the aerobic cometabolism of chlorinated solvents.


Asunto(s)
Butanos/metabolismo , Etano/análogos & derivados , Agua Subterránea/microbiología , Hidrocarburos Clorados/metabolismo , Consorcios Microbianos/fisiología , Tricloroetileno/metabolismo , Contaminantes Químicos del Agua/metabolismo , Biodegradación Ambiental , Biomasa , Reactores Biológicos , Etano/metabolismo , Agua Subterránea/química , Concentración de Iones de Hidrógeno , Cinética , Temperatura
8.
J Hazard Mater ; 469: 133878, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38447365

RESUMEN

Microbial reductive dechlorination of organohalogenated pollutants is often limited by the scarcity of electron donors, that can be overcome with microbial electrochemical technologies (METs). In this study, polarized electrodes buried in marine sediment microcosms were investigated to stimulate PCB reductive dechlorination under potentiostatic (-0.7 V vs Ag/AgCl) and galvanostatic conditions (0.025 mA·cm-2-0.05 mA·cm-2), using graphite rod as cathode and iron plate as sacrificial anode. A single circuit and a novel two antiparallel circuits configuration (2AP) were investigated. Single circuit polarization impacted the sediment pH and redox potential (ORP) proportionally to the intensity of the electrical input and inhibited PCB reductive dechlorination. The effects on the sediment's pH and ORP, along with the inhibition of PCB reductive dechlorination, were mitigated in the 2AP system. Electrodes polarization stimulated sulfate-reduction and promoted the enrichment of bacterial clades potentially involved in sulfate-reduction as well as in sulfur oxidation. This suggested the electrons provided were consumed by competitors of organohalide respiring bacteria and specifically sequestered by sulfur cycling, which may represent the main factor limiting the applicability of METs for stimulating PCB reductive dechlorination in marine sediments.


Asunto(s)
Microbiota , Bifenilos Policlorados , Bifenilos Policlorados/análisis , Biodegradación Ambiental , Bacterias , Sedimentos Geológicos/microbiología , Electrodos , Sulfatos , Azufre , Cloro
9.
Can J Physiol Pharmacol ; 91(2): 171-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23458202

RESUMEN

Among the numerous coadjuvant therapies that could influence the incidence and progression of diabetic complications, antioxidants and flavonoids are currently being tested in clinical trials. We investigated the effect of quercetin on biochemical parameters in streptozotocin-induced (60 mg/kg body mass, by intraperitoneal injection) diabetic rats. A total of 32 female Wistar rats were distributed among 4 groups as follows: control (G1); control treated with quercetin (G2); diabetic (G3); and diabetic treated with quercetin (G4). Quercetin administered to pregnant diabetic rats controlled dyslipidemia and improved lipid profiles in diabetes mellitus, regulated oxidative stress by reducing the generation of lipid hydroperoxides, and increased the activity of the antioxidant enzyme glutathione peroxidase.


Asunto(s)
Antioxidantes/uso terapéutico , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Lípidos/sangre , Estrés Oxidativo/efectos de los fármacos , Embarazo en Diabéticas/tratamiento farmacológico , Quercetina/uso terapéutico , Animales , Antioxidantes/administración & dosificación , Glucemia/metabolismo , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/metabolismo , Femenino , Glutatión Peroxidasa/sangre , Peróxidos Lipídicos/sangre , Masculino , Embarazo , Embarazo en Diabéticas/sangre , Embarazo en Diabéticas/metabolismo , Quercetina/administración & dosificación , Ratas , Ratas Wistar , Resultado del Tratamiento
10.
Sci Total Environ ; 898: 165485, 2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-37442469

RESUMEN

The use of biodegradable plastics is constantly raising, increasing the likeliness for these polymers to end up in the environment. Environmental applications foreseeing the intentional release of biodegradable plastics have been also recently proposed, e.g., for polyhydroxyalkanoates (PHAs) acting as slow hydrogen releasing compounds to stimulate microbial reductive dehalogenation processes. However, the effects of their release into the environment on the ecosystems still need to be thoroughly explored. In this work, the use of PHAs to enhance the microbial reductive dechlorination of polychlorobiphenyls (PCBs) and their impact on the metabolic and compositional features of the resident microbial community have been investigated in laboratory microcosms of a polluted marine sediment from Mar Piccolo (Taranto, Italy), and compared with recent findings on a different contaminated marine sediment from Pialassa della Baiona (Ravenna, Italy). A decreased biostimulation efficiency of PHAs on PCBs reductive dechlorination was observed in the sediment from Mar Piccolo, with respect to the sediment from Pialassa della Baiona, suggesting that the sediments' physical-chemical characteristics and/or the biodiversity and composition of its microbial community might play a key role in determining the outcome of this biostimulation strategy. Regardless of the sediment origin, PHAs were found to have a specific and pervasive effect on the sediment microbial community, reducing its biodiversity, defining a newly arranged microbial core of primary degraders and consequently affecting, in a site-specific way, the abundance of subdominant bacteria, possibly cross-feeders. Such potential to dramatically change the structure of autochthonous microbial communities should be carefully considered, since it might have secondary effects, e.g., on the natural biogeochemical cycles.


Asunto(s)
Plásticos Biodegradables , Microbiota , Bifenilos Policlorados , Polihidroxialcanoatos , Bifenilos Policlorados/análisis , Biodegradación Ambiental , Sedimentos Geológicos/química , Suplementos Dietéticos
11.
Mar Pollut Bull ; 186: 114458, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36493518

RESUMEN

The effect of polyhydroxyalkanoates (PHAs) with different composition on the reductive dechlorination activity of a polychlorinated biphenyls (PCBs) dechlorinating marine microbial community and on the activity of sulfate-reducing (SRB) and methanogenic bacteria (MB), were investigated in marine sediment microcosms and compared with the main monomer, 3-hydroxybutyric acid (3HB). Despite PHAs were fermented more slowly than 3HB, all electron donors stimulated constantly sulfate-reduction, methanogenesis and, only transiently, PCB reductive dechlorination. No relevant differences were observed with different compositions of PHAs. According to electron balances, the majority of the supplied electrons (50 %) were consumed by SRB and to less extent by MB (9-31 %), while a small percentage (0.01 %) was delivered to OHRB. In the studied conditions PHAs were confirmed as potential slow­hydrogen releasing compounds in marine environment but their fermentation rate was sufficiently high to mainly stimulate the competitors of organohalide respring bacteria for electron donors.


Asunto(s)
Chloroflexi , Bifenilos Policlorados , Biodegradación Ambiental , Anaerobiosis , Chloroflexi/genética , ARN Ribosómico 16S , Sulfatos , Sedimentos Geológicos/microbiología , Respiración
12.
Nutrition ; 105: 111861, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36401998

RESUMEN

Front-of-pack labels (FOPLs) aim at communicating to consumers the health value of food items in support of public health policies. Two main types can be discerned: directive and semidirective FOPLs using color schemes (e.g., Nutri-Score) and informative FOPLs (e.g., Nutrinform Battery). Directive approaches tend to show a "wear-out effect" and, additionally, they tend to have various underlying conceptual problems. Usually, their nutritional scores are calculated using changing, arbitrary algorithms and involve a reductionist set of parameters of debatable validity. Thus, they overstate the effects of selected nutritional factors, such as saturated fat and energy, while overlooking the food matrix and the more holistic aspects of nourishment. Moreover, they do not reflect the portion that is consumed, ignore the preparation steps at home, and fail to serve as a useful basis for composing a healthy diet. Also, so long as the nutritional formulations match the algorithmic standards, they tend to allow ultra-processed products. Thus, this might confuse and mislead consumers. Overconfidence in green-colored labels could even result in unbalanced dietary choices, whereas avoidance of red products may eliminate certain foods from the diet that are rich in essential nutrients (e.g., cheese), leading to opposite results than aimed for. The latter is particularly relevant to vulnerable populations, such as the young, pregnant women, and older adults, or for individuals with specific needs. Taken together, directive FOPLs such as Nutri-Score contradict the declared intent of the European Commission to empower consumers to undertake healthy and balanced diets based on easily accessible and robust information. Although informative systems usually also keep the focus on a few selected nutritional parameters, they have are less paternalizing and obviate the need to classify foods as healthy or unhealthy. They also focus attention on the individual portions that are consumed (even if the definition of portion size remains contentious). Given the importance of dietary patterns, rather than individual foods or nutrients, directiveFOPLs of the Nutri-Score type represent a regretful case of nutritionism. Finally, attempts to associate the adoption of a FOPL with an improvement in the health status are few and mainly applied in virtual settings; none of which are longitudinal, nor have they been able to identify a causal link.


Asunto(s)
Dieta Saludable , Etiquetado de Alimentos , Humanos , Femenino , Embarazo , Anciano , Valor Nutritivo , Dieta , Comportamiento del Consumidor , Preferencias Alimentarias
13.
Microb Cell Fact ; 11: 35, 2012 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-22443185

RESUMEN

BACKGROUND: Several species belonging to the ecological group of white-rot basidiomycetes are able to bring about the remediation of matrices contaminated by a large variety of anthropic organic pollutants. Among them, polychlorobiphenyls (PCBs) are characterized by a high recalcitrance due to both their low bioavailability and the inability of natural microbial communities to degrade them at significant rates and extents. Objective of this study was to assess the impact of a maize stalk-immobilized Lentinus tigrinus CBS 577.79 inoculant combined with soybean oil (SO), as a possible PCB-mobilizing agent, on the bioremediation and resident microbiota of an actual Aroclor 1260 historically contaminated soil under unsaturated solid-phase conditions. RESULTS: Best overall PCB depletions (33.6 ± 0.3%) and dechlorination (23.2 ± 1.3%) were found after 60 d incubation in the absence of SO where, however, the fungus appeared to exert adverse effects on both the growth of biphenyl- and chlorobenzoate-degrading bacteria and the abundance of genes coding for both biphenyl dioxygenase (bph) and catechol-2,3-dioxygenase. A significant (P < 0.001) linear inverse relationship between depletion yields and degree of chlorination was observed in both augmented and control microcosms in the absence of SO; conversely, this negative correlation was not evident in SO-amended microcosms where the additive inhibited the biodegradation of low chlorinated congeners. The presence of SO, in fact, resulted in lower abundances of both biphenyl-degrading bacteria and bph. CONCLUSIONS: The PCB depletion extents obtained in the presence of L. tigrinus are by far higher than those reported in other remediation studies conducted under unsaturated solid phase conditions on actual site soils historically contaminated by Aroclor 1260. These results suggest that the bioaugmentation strategy with the maize stalk-immobilized mycelium of this species might be promising in the reclamation of PCB-contaminated soils. The addition of SO to matrices contaminated by technical PCB mixtures, such as Aroclor 1242 and Delor 103 and characterized by a large preponderance of low chlorinated congeners, might not be advisable.


Asunto(s)
Biodegradación Ambiental , Lentinula/enzimología , Bifenilos Policlorados/metabolismo , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Catecol 2,3-Dioxigenasa/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Hierro-Azufre/metabolismo , Oxigenasas/metabolismo , Bifenilos Policlorados/química , Contaminantes del Suelo/química , Aceite de Soja/química , Aceite de Soja/metabolismo
14.
Polymers (Basel) ; 14(9)2022 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-35567020

RESUMEN

Commercial hydrolytic enzymes belonging to different subclasses (several lipases, proteinase k, cutinase) were investigated for their ability to degrade different aliphatic polyesters, i.e., poly(butylene succinate) (PBS), poly(butylene succinate-co-adipate) (PBSA), two poly(caprolactone), having two different molecular weights, poly(lactic acid) (PLA) and poly(propylene carbonate) (PPC). The enzyme screening was first carried out by investigating the capacity of fully degrading the target polymers in 24 h, then weight loss measurements of selected polyesters and target enzymes were performed. Solid residues after enzyme degradation were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetry (TGA). Liquid fractions were studied via GPC, 1H NMR and high-performance liquid chromatography (HPLC). PCL and PBSA were found to be the most biodegradable polyesters, under the conditions used in this study. PBS was fully degraded only by cutinase, whereas none of the tested enzymes were able to completely degrade PLA and PPC, in the conditions assessed here. Cutinase exhibited the highest hydrolytic activity on PBSA, while lipase from Candida sp. (CALB) on low molecular weight PCL. Chemical analyses on residual solids showed that the enzymatic degradation occurred homogeneously from the surface through an erosion mechanism and did not significantly affect the macromolecular structure and thermal stability. Cleaving action mode for each enzyme (endo- and/or exo-type) on the different polyesters were also proposed based on the evaluation of the degradation products in the liquid fraction.

15.
Environ Pollut ; 315: 120411, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36240963

RESUMEN

Plastic debris dispersed into the environment provide a substrate for microbial colonization, constituting a new human-made ecosystem called "plastisphere", and altering the microbial species distribution in aquatic, coastal and benthic ecosystems. The study aims at exploring the interaction among microplastics (MPs) made of different polymers, a persistent organic contaminant (polychlorinated biphenyls, PCBs), and the environmental microbial communities, in an anoxic marine sediment. Plastic pellets were incubated in the field in a salt marsh anoxic sediment, to observe the stages of plastisphere formation, by quantitative PCR and 16S rRNA gene sequencing, and PCB dechlorination activity on the MPs surface. Microbes from the sediment rapidly colonized the different microplastics types, with PVC recruiting a peculiar community enriched in sulfate-reducing bacteria. The composition of the plastisphere varied along the 1-year incubation possibly in response either to warmer temperatures in spring-summer or to microhabitat's changes due to the progressive plastic surface weathering. Even if PCB contaminated MPs were able to recruit potentially dehalogenating taxa, actual dechlorination was not detectable after 1 year. This suggests that the concentration of potentially dehalorespiring bacteria in the natural environment could be too low for the onset of the dechlorination process on MP-sorbed contaminants. Our study, which is among very few available longitudinally exploring the plastisphere composition in an anoxic sediment context, is the first exploring the fate and possible biodegradation of persistent organic pollutants sorbed on MPs reaching the seafloor.


Asunto(s)
Microbiota , Bifenilos Policlorados , Humanos , Bifenilos Policlorados/análisis , Microplásticos , Plásticos , ARN Ribosómico 16S/genética , Humedales
16.
Ecotoxicol Environ Saf ; 74(3): 253-8, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21087794

RESUMEN

Nonylphenol ethoxylates (NPnEOs, where n is the number of ethoxylic units in the molecule) are non-ionic surfactants widely used for domestic and industrial purposes. 4-Nonylphenol (4-NP), the main product of NPnEO biodegradation, is a toxic xenobiotic compound classified as endocrine disrupter. While numerous studies reported the toxicity and oestrogenic activity of nonylphenols, little is known about the mutagenicity of these compounds. In this paper, the genotoxicity of 4-NP and NPnEO mixtures was evaluated by using the D7 strain of Saccharomyces cerevisiae as experimental model. The same genotoxicity tests were applied to effluents deriving from experimental packed-bed bioreactors, developed for the treatment of NPnEO contaminated wastewater, in order to evaluate the residual genotoxic potential with respect to the influent waste. The target compounds fed to the bioreactors were 4-NP and NPnEO mixtures possessing an average of 5 or 1.5 ethoxylic units (Igepal CO-520 and Igepal CO-210, respectively). The results showed that 4-NP induced significant cytotoxic effect on S. cerevisiae cells at 50 mg/L, as well as mutagenic effects at the lowest tested concentrations (12 and 25 mg/L). 4-NP was the most genotoxic compound among those assayed, followed by Igepal CO-210, whereas Igepal CO-520 did not induce genotoxicity at any of the assayed concentrations. The genotoxic effects of 4-NP on yeast cells disappeared after the treatment of 4-NP artificially contaminated water in the bioreactor. This indicates that the biological treatment is capable of removing not only the pollutant, but also the toxicity associated to the compound and its degradation metabolites. This study represents, to the best of our knowledge, the first report that evaluates the genotoxicity of both 4-NP, NPnEOs and their potential aerobic degradation products on an eukaryotic organism. The obtained results suggest that the S. cerevisiae D7 strain is a very effective model microorganism to study the induction of genotoxic damage by the compounds under study. Moreover, this yeast assay has been proved effective to evaluate the detoxification effect deriving from biotreatment processes.


Asunto(s)
Disruptores Endocrinos/toxicidad , Mutágenos/toxicidad , Fenoles/toxicidad , Saccharomyces cerevisiae/efectos de los fármacos , Biodegradación Ambiental , Bioensayo , Reactores Biológicos/microbiología , Pruebas de Mutagenicidad , Saccharomyces cerevisiae/metabolismo , Microbiología del Agua , Contaminantes Químicos del Agua/toxicidad
17.
N Biotechnol ; 61: 124-136, 2021 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-33220517

RESUMEN

Italy has the third largest bioeconomy in Europe (€330 billion annual turnover, 2 million employees), making it a core pillar of the national economy. Its sectors of excellence are food and biobased products, and it is a consistent presence in research and innovation projects funded by the EU Horizon 2020 programme (Societal Challenges 2) and the European Public Private Partnership "Biobased industry" (BBI-JU). The bioeconomy reduces dependence on fossil fuels and finite materials, loss of biodiversity and changing land use. It contributes to environmental regeneration, spurs economic growth and supports jobs in rural, coastal and abandoned industrial areas, leveraging local contexts and traditions. In 2017 the Italian government promoted the development of a national Bioeconomy Strategy (BIT), recently updated (BIT II) to interconnect more efficiently the pillars of the national bioeconomy: production of renewable biological resources, their conversion into valuable food/feed, biobased products and bio-energy, and transformation and valorization of bio-waste streams. BIT II aims to improve coordination between Ministries and Italian regions in alignment of policies, regulations, R&I funding programmes and infrastructures investment. The goal is a 15 % increase in turnover and employment in the Italian bioeconomy by 2030. Based on Italy's strategic geopolitical position in the Mediterranean basin, BIT II also includes actions to improve sustainable productivity, social cohesion and political stability through the implementation of bioeconomy strategies in this area. This paper provides an insight into these strategies and discusses the strengths and weaknesses of the sectors involved and the measures, regulatory initiatives and monitoring actions undertaken.


Asunto(s)
Biotecnología , Conservación de los Recursos Naturales , Asociación entre el Sector Público-Privado , Humanos , Italia
18.
FEBS Open Bio ; 11(4): 967-983, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33595898

RESUMEN

Building new value chains, through the valorization of biomass components for the development of innovative bio-based products (BBPs) aimed at specific market sectors, will accelerate the transition from traditional production technologies to the concept of biorefineries. Recent studies aimed at mapping the most relevant innovations undergoing in the field of BBPs (Fabbri et al. 2019, Final Report of the Task 3 BIOSPRI Tender Study on Support to R&I Policy in the Area of Bio-based Products and Services, delivered to the European Commission (DG RTD)), clearly showed the dominant position played by the plastics sector, in which new materials and innovative technical solutions based on renewable resources, concretely contribute to the achievement of relevant global sustainability goals. New sustainable solutions for the plastic sector, either bio-based or bio-based and biodegradable, have been intensely investigated in recent years. The global bioplastics and biopolymers market size is expected to grow from USD 10.5 billion in 2020 to USD 27.9 billion by 2025 (Markets and Markets, 2020, Bioplastics & Biopolymers Market by Type (Non-Biodegradable/Bio-Based, Biodegradable), End-Use Industry (Packaging, Consumer Goods, Automotive & Transportation, Textiles, Agriculture & Horticulture), Region - Global Forecast to 2025), and this high growth is driven primarily by the growth of the global packaging end-use industry. Such relevant opportunities are the outcomes of intensive scientific and technological research devoted to the development of new materials with selected technical features, which can represent feasible substitutes for the fossil-based plastic materials currently used in the packaging sectors and other main fields. This article offers a map of the latest developments connected to the plastic sector, achieved through the application of biotechnological routes for the preparation of completely new polymeric structures, or drop-in substitutes derived from renewable resources, and it describes the specific role played by biotechnology in promoting and making this transition faster.


Asunto(s)
Plásticos Biodegradables/química , Biopolímeros/química , Biotecnología , Plásticos/química , Biodegradación Ambiental , Biotecnología/métodos , Humanos , Energía Renovable , Crecimiento Sostenible
19.
Nutrients ; 13(11)2021 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-34836203

RESUMEN

Ultra-processed foods (UPFs) are negatively perceived by part of the scientific community, the public, and policymakers alike, to the extent they are sometimes referred to as not "real food". Many observational surveys have linked consumption of UPFs to adverse health outcomes. This narrative synthesis and scientific reappraisal of available evidence aims to: (i) critically evaluate UPF-related scientific literature on diet and disease and identify possible research gaps or biases in the interpretation of data; (ii) emphasize the innovative potential of various processing technologies that can lead to modifications of the food matrix with beneficial health effects; (iii) highlight the possible links between processing, sustainability and circular economy through the valorisation of by-products; and (iv) delineate the conceptual parameters of new paradigms in food evaluation and classification systems. Although greater consumption of UPFs has been associated with obesity, unfavorable cardiometabolic risk factor profiles, and increased risk for non-communicable diseases, whether specific food processing techniques leading to ultra-processed formulations are responsible for the observed links between UPFs and various health outcomes remains elusive and far from being understood. Evolving technologies can be used in the context of sustainable valorisation of food processing by-products to create novel, low-cost UPFs with improved nutritional value and health potential. New paradigms of food evaluation and assessment should be funded and developed on several novel pillars-enginomics, signalling, and precision nutrition-taking advantage of available digital technologies and artificial intelligence. Research is needed to generate required scientific knowledge to either expand the current or create new food evaluation and classification systems, incorporating processing aspects that may have a significant impact on health and wellness, together with factors related to the personalization of foods and diets, while not neglecting recycling and sustainability aspects. The complexity and the predicted immense size of these tasks calls for open innovation mentality and a new mindset promoting multidisciplinary collaborations and partnerships between academia and industry.


Asunto(s)
Comida Rápida , Manipulación de Alimentos , Comida Rápida/economía , Manipulación de Alimentos/economía , Salud , Humanos , Invenciones , Valor Nutritivo
20.
Microb Cell Fact ; 9: 3, 2010 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-20089184

RESUMEN

Volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked renewed interest in the production of fuels from renewable resources. Recent advances in synthetic biology provide new tools for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels. Metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for conversion of biomass constituents to short-chain alcohols and advanced biofuels are herewith reviewed. In the foreseeable future, formal integration of functional genomics and systems biology with synthetic biology and metabolic engineering will undoubtedly support the discovery, characterization, and engineering of new metabolic routes and more efficient microbial systems for the production of biofuels.


Asunto(s)
Alcoholes/metabolismo , Biocombustibles/análisis , Biotecnología/métodos , Fuentes Generadoras de Energía , Bacterias/genética , Bacterias/metabolismo , Hongos/genética , Hongos/metabolismo
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