Browsing by Author "Deuchande, Teresa"
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- Antimicrobial potential of formulations, incorporating spent yeast derived from synthetic biotechnology, against Pseudomonas spp.Publication . Deuchande, Teresa; Fundo, Joana; Rodrigues, Daniela; Souza, Carla; Pintado, Manuela; Amaro, Ana L.Yeasts are currently used as cell factories for the sustainable production of high value biomolecules for applications in the pharmaceutical and cosmetic sectors. However, the production of such molecules through fermentation, conducted in bioreactors and making use of genetically engineered yeast strains, generates a number of waste-streams, with spent yeast as the second main by-product of fermentation processes, representing more than 20% of the total waste produced. Since this by-product is rich in several molecules including proteins, vitamins and several minerals, being also a natural source of glucans and mannoproteins with known bioactivities, it is of interest to develop valorization strategies for these residues. In this work, spent yeast was autolysed and a set of formulations, incorporating the resulting supernatant and pellet at different concentrations, were tested as potential antimicrobial solutions to prevent diseases in plants and fungi caused by Pseudomonas spp. The formulations were initially tested against P. aeruginosa and then against strains affecting cultivated mushrooms (Agaricus bisporus), P. tolaasi, and P. agarici; and a number of P. syringae strains responsible for plant diseases including the pathovars actinidifoliorium, tomato, pisi, syringae and atrofaciens. It has been recently shown that spent yeast hydrolysates possess antimicrobial activity against Salmonella enterica, Aeromonas salmonicida, Bacillus cereus and Bacillus subtilis (Martin et al. 2021), suggesting that spent yeast extracts may have potential antimicrobial effect against a range of microorganisms. To date, there are no studies showing the potential of spent yeast extracts against Pseudomonas strains. The results showed that the supernatant of the autolyzed yeast at 0.1% inhibited the growth of P. aeruginosa by about 20% and P. tolaasii by 10% but increased the growth of P. agarici by up to 34%. The combination of supernatant with lactose also slightly increased P. tolaasii growth inhibition (12%) but it reduced the inhibitory effect of supernatant against P. aeruginosa. With regard to plant pathogens, the formulations containing 0.1% and 0.3% of pellet inhibited by 25% the growth P. syringae pv. actinidifoliorium, the bacterium responsible for kiwi canker, but for all the other pathovars, the inclusion of spent yeast extracts in the formulation induced bacterial growth. Among all the tested formulations, the ones including supernatant and pellet at low concentrations were the most promising leading to slight growth inhibition of some environmental Pseudomonas spp.
- Atmosfera controlada dinâmica na prevenção do acastanhamento interno em pera rocha: eficácia dos sensores de etanol e de fluorescência de clorofilasPublication . Deuchande, Teresa; Carvalho, Susana M. P.; Larrigaudière, Christian; Fidalgo, Fernanda; Guterres, Umbelina; Isidoro, Nélson; Vasconcelos, MartaA pera ‘Rocha’ é suscetível ao desenvolvimento de acastanhamento interno (AI) durante o armazenamento prolongado em atmosfera controlada estática (ACE). Este estudo teve como objetivo avaliar o potencial da atmosfera controlada dinâmica (ACD) monitorizada por dois tipos de sensor (etanol e fluorescência de clorofilas) na prevenção do AI em pera ‘Rocha’, com enfase no metabolismo fermentativo e sistema antioxidante. Neste estudo, peras de um pomar foram armazenadas em três câmaras comerciais de atmosfera controlada durante 145 dias, com as seguintes condições de armazenamento: 1) ACD monitorizada por um sensor de etanol (ACD-EtOH); 2) ACD monitorizada por um sensor de fluorescência de clorofilas (ACD-FC); 3) ACE. No final do armazenamento os frutos em ACD-FC e ACE não foram afetados por AI, ao contrário dos frutos armazenados em ACD-EtOH, os quais apresentaram uma incidência de 15% após 125 dias e 20% após 145 dias de armazenamento. A elevada incidência de AI nos frutos armazenados em ACD-EtOH após 125 dias pareceu estar maioritariamente relacionada com os elevados níveis de etanol observado nestes frutos, comparativamente com os níveis detetados nos frutos da ACD-FC e ACE. Embora, após 125 dias, tenha ocorrido uma diminuição dos níveis de ácido ascórbico nos frutos da ACD-EtOH, após 145 dias os frutos superaram este decréscimo e os valores foram superiores aos registados nos frutos das outras condições de armazenamento. Estes resultados sugerem que a utilização do sensor de fluorescência de clorofilas para ajustar os níveis de oxigénio durante o armazenamento em ACD é uma estratégia eficaz na prevenção do AI em pera "Rocha". Pelo contrário, a informação dada pelo sensor de etanol parece ser insuficiente para evitar a indução do metabolismo fermentativo. Os resultados sugerem ainda, que a principal causa do AI em pera ‘Rocha’ poderá estar, primariamente relacionada com o metabolismo fermentativo.
- Biochemical basis of CO2-related internal browning disorders in pears (Pyrus communisL. cv. Rocha) during long-term storagePublication . Deuchande, Teresa; Larrigaudière, Christian; Giné-Bordonaba, Jordi; Carvalho, Susana; Vasconcelos, Marta W.This study aimed at understanding the biochemical basis of internal browning disorders (IBDs) in 'Rocha' pear. For this purpose, the effects of storage under normal controlled atmosphere (CA) (3 kPa of O2 + 0.5 kPa of CO2) and IBD-inducing CA (1 kPa of O2 + 10 kPa of CO2) on the antioxidant and fermentative metabolisms and polyphenol oxidase (PPO) activity and phenolics concentration were studied. The higher IBD incidence in high CO2-stored fruits was positively correlated with fermentative metabolites and negatively with ascorbate and H2O2 concentrations, and it was linked to PPO activation. These results indicate that both the antioxidant and fermentative metabolisms are involved in the occurrence of IBD in 'Rocha' pear. From the integration of the biochemical and enzymatic data, a schematic model illustrating the effects of high CO2 and low O2 in 'Rocha' pears during long-term storage was constructed.
- Biochemical markers to predict internal browning disorders in ‘Rocha’ pear during storage under high CO2Publication . Deuchande, Teresa; Larrigaudière, Christian; Guterres, Umbelina; Carvalho, Susana M. P.; Vasconcelos, Marta W.BACKGROUND: The aim of this studywas to identify biochemical markers to predict internal browning disorders (IBD) in 'Rocha' pear. Fruits from five orchards were stored for 45 days under cold air followed by 100 days in browning-inducing controlled atmosphere (CA) conditions (1 kPaO(2) + 10 kPaCO(2)). RESULTS: Relationships between concentrations of ethanol (EtOH), acetaldehyde (AcDH) and ascorbic acid (AA), activities of peroxidase (POX) and polyphenoloxidase (PPO) and IBD incidence were established. The partial least square (PLS) model using the most promising markers, EtOH and AcDH, explained 89% of the variance in IBD incidence, whereas the univariate models based on the same markers explained between 89 and 94%. In contrast, the models based on AA levels and AA depletion rate only explained 57 and 82% of the variance in IBD incidence respectively. Model validation confirmed the robustness of EtOH for the prediction (R-2 = 0.91, RMSE= 11.1) and allowed proposing a threshold level of 30 mu L EtOH L-1 above which IBD may occur. Using this threshold value, the storage time limit associated with the occurrence of the first IBD symptoms was predicted with an acceptable RMSE of 9 days. CONCLUSION: Thiswork clearly identifies biochemical IBDmarkers for ` Rocha' pear and shows that dynamic changes in ethanol concentration during the beginning of storagemay be used to predict IBD development. Therefore the results presented herein represent a major step forward in the prediction of IBD in 'Rocha' pear.
- Characterization of spent yeast streams from precision fermentations driven by genetically engineered yeasts: valorization potential for a circular bioeconomyPublication . Deuchande, Teresa; Fundo, Joana F.; Rodrigues, Daniela; Pintado, Manuela E.; Amaro, Ana L.Currently, valuable biomolecules are sustainably produced through fermentation using genetically modified microorganisms. However, this industry also generates several waste streams, such as spent yeast (SY). To close the sustainability loop in bioproduction, it is essential to define valorization strategies for such waste streams. Hence, this study aimed to investigate the compositional differences among these novel SYs, intending to pave the way for devising highly effective and beneficial valorization strategies for these streams. In this work, SYs derived from the production of beer (SBY) and six biomolecules [β-farnesene (Fene), rebaudioside M (Reb M), manool (MN), patchouli (PAT), sandalwood (SDW), and sclareol (SCL)] through fermentations driven by engineered yeasts were characterized. The results showed that SY from Fene, MN, and PAT production have similar concentrations of protein (35.9–44% dw), minerals, and amino acids, being compatible with bulking and use as nitrogen sources. Those derived from Reb M production showed significantly higher levels of lipids (21 ± 2.6% dw) compared to all the other SYs (1.7–10.8% dw), whereas the ones derived from SCL production showed significantly higher levels of inorganic matter (45%) compared with those found in the other SYs (1.2–11.3% dw). The results showed that assessing the extent of compositional variation among different SYs derived from precision fermentations represents a primary step toward developing efficient valorization or biorefining strategies.
- Combined effect of elevated CO2 and Fe deficiency on common bean metabolism and mineral profilePublication . Deuchande, Teresa; Vasconcelos, MartaAims: Elevated atmospheric CO2 (eCO2) and restricted iron (Fe) supply are known to impact plant growth and nutritional quality of food crops. However, studies aimed at understanding how eCO2 will interact with Fe deficiency are scarce. Changes in the nutritional status of the common bean (Phaseolus vulgaris L.) may significantly impact the nutritional status of populations that rely heavily on this crop. Methods: To understand the combined effects of eCO2 and Fe deficiency on mechanisms relevant to plant nutrient uptake and accumulation, common bean plants were grown under Fe sufficiency (Fe+, 20 mM Fe-EDDHA) and Fe deficiency (Fe-, 0 mM Fe-EDDHA) combined with eCO2 (800 ppm) or ambient CO2 (aCO2, 400 ppm) in hydroponics until maturity. Results: Elevated CO2, besides stimulating photosynthesis and stomatal closure, highly affected plant Fe metabolism: stimulated root ferric chelate reductase (FCR) activity by 6-fold and downregulated the expression of root FRO1 and IRT1 expressions by about 4-fold. In leaves, citrate and oxalate increased, but ferritin expression decreased by 9-fold. Such changes may have determined the differences on mineral accumulation patterns particularly the lower levels of Fe in roots (62%), leaves (38%) and seeds (50%). The combination of Fe deficiency and eCO2 doubled the effect of a single factor on FCR up-regulation, balanced the internal pH of Fe deficient plants, and resulted in the lowest Fe accumulation in all plant parts. Conclusions: These results suggest that eCO2 directly affects the Fe uptake mechanism of common bean plants, decreasing plant Fe content.
- Dynamic controlled atmosphere for prevention of internal browning disorders in ‘Rocha’ pearPublication . Deuchande, Teresa; Carvalho, Susana; Guterres, Umbelina; Fidalgo, Fernanda; Isidoro, Nelson; Larrigaudière, Christian; Vasconcelos, Marta W.This study aimed to evaluate the potential of two dynamic controlled atmospheres, DCA-CF (chlorophyll fluorescence sensor) and DCA-EtOH (ethanol sensor) when compared to controlled atmosphere (CA), in the prevention of internal browning disorders (IBD) in ‘Rocha’ pear stored under commercial conditions. Pears harvested at optimal maturity were stored for 145 days at 0.5 C and 95% relative humidity, under three atmospheres: (1) CA (3 kPa O2 þ 0.5 kPa CO2), (2) DCA-CF and (3) DCA-EtOH. At the end of storage, fruits in DCA-CF did not develop IBD while fruits in DCA-EtOH had an IBD incidence of 15 and 20% after 125 and 145 days of storage, respectively. The higher incidence of IBD under DCA-EtOH may be related to the higher levels of fermentative metabolites and to the lower ascorbate content. In contrast, the higher levels of ascorbate in DCA-CF showed that this technology contributes to maintaining the fruit's antioxidant potential. Collectively our results suggest that DCA-CF is an effective strategy to prevent IBD in ‘Rocha’ pear. On the contrary, the DCA-EtOH is not suitable to prevent the induction of fermentation and IBD development. The results also suggest that the IBD development in ‘Rocha’ pear is related to fermentative metabolism.
- Growth and nutritional responses of bean and soybean genotypes to elevated CO2 in a controlled environmentPublication . Soares, José; Deuchande, Teresa; Valente, Luísa M. P.; Pintado, Manuela; Vasconcelos, Marta W.In the current situation of a constant increase in the atmospheric CO2 concentration, there is a potential risk of decreased nutritional value and food crop quality. Therefore, selecting strong-responsive varieties to elevated CO2 (eCO2) conditions in terms of yield and nutritional quality is an important decision for improving crop productivity under future CO2 conditions. Using bean and soybean varieties of contrasting responses to eCO2 and different origins, we assessed the effects of eCO2 (800 ppm) in a controlled environment on the yield performance and the concentration of protein, fat, and mineral elements in seeds. The range of seed yield responses to eCO2 was −11.0 to 32.7% (average change of 5%) in beans and −23.8 to 39.6% (average change of 7.1%) in soybeans. There was a significant correlation between seed yield enhancement and aboveground biomass, seed number, and pod number per plant. At maturity, eCO2 increased seed protein concentration in beans, while it did not affect soybean. Lipid concentration was not affected by eCO2 in either legume species. Compared with ambient CO2 (aCO2), the concentrations of manganese (Mn), iron (Fe), and potassium (K) decreased significantly, magnesium (Mg) increased, while zinc (Zn), phosphorus (P), and calcium (Ca) were not changed under eCO2 in bean seeds. However, in soybean, Mn and K concentrations decreased significantly, Ca increased, and Zn, Fe, P, and Mg concentrations were not significantly affected by eCO2 conditions. Our results suggest that intraspecific variation in seed yield improvement and reduced sensitivity to mineral losses might be suitable parameters for breeders to begin selecting lines that maximize yield and nutrition under eCO2.
- Impact of climate change on plant nutritionPublication . Vasconcelos, Marta W.; Deuchande, Teresa; Soares, João; Nunes, F.; Pintado, M. E.
- Impact of elevated CO2 and restricted iron supply on soybean (Glycine max) and common bean (Phaseolus vulgaris) growth and nutritionPublication . Deuchande, Teresa; Soares, Jose; Nunes, Fabio; Pinto, Elisabete; Vasconcelos, Marta