Twists and turns in the salicylate catabolism of aspergillus terreus, revealing new roles of the 3-hydroxyanthranilate pathway

This work was financially supported by Fundacao para a Ciencia e a Tecnologia (FCT), project MOSTMICRO ITQB with reference no. UIDB/04612/2020 and UIDP/04612/2020, and by project "PinusResina" no. PDR2020-101-031905, funded by PDR2020 through Portugal2020. This research was carried out through a partnership with the RESOLUTION LAB, an infrastructure at NOVA School of Science and Technology. The authors acknowledge and thank the support given by the Portuguese Foundation for Science and Technology (FCT) to CENSE through the strategic project UIDB/04085/2020. T.M. and C.M. are grateful to FCT for the working contract financed by national funds under Norma Transitoria D.L. no. 57/2016 and the fellowship SFRH/BD/118377/2016, respectively.In fungi, salicylate catabolism was believed to proceed only through the catechol branch of the 3-oxoadipate pathway, as shown, e.g., in Aspergillus nidulans. However, the observation of a transient accumulation of gentisate upon the cultivation of Aspergillus terreus in salicylate medium questions this concept. To address this, we have run a comparative analysis of the transcriptome of these two species after growth in salicylate using acetate as a control condition. The results revealed the high complexity of the salicylate metabolism in A. terreus with the concomitant positive regulation of several pathways for the catabolism of aromatic compounds. This included the unexpected joint action of two pathways—3-hydroxyanthranilate and nicotinate—possibly crucial for the catabolism of aromatics in this fungus. Importantly, the 3-hydroxyanthranilate catabolic pathway in fungi is described here for the first time, whereas new genes participating in the nicotinate metabolism are also proposed. The transcriptome analysis showed also for the two species an intimate relationship between salicylate catabolism and secondary metabolism. This study emphasizes that the central pathways for the catabolism of aromatic hydrocarbons in fungi hold many mysteries yet to be discovered. IMPORTANCE Aspergilli are versatile cell factories used in industry for the production of organic acids, enzymes, and pharmaceutical drugs. To date, bio-based production of organic acids relies on food substrates. These processes are currently being challenged to switch to renewable nonfood raw materials—a reality that should inspire the use of lignin-derived aromatic monomers. In this context, aspergilli emerge at the forefront of future bio-based approaches due to their industrial relevance and recognized prolific catabolism of aromatic compounds. Notwithstanding considerable advances in the field, there are still important knowledge gaps in the central catabolism of aromatic hydrocarbons in fungi. Here, we disclose a novel central pathway, 3-hydroxyanthranilate, defying previously established ideas on the central metabolism of the aromatic amino acid tryptophan in Ascomycota. We also observe that the catabolism of the aromatic salicylate greatly activated the secondary metabolism, furthering the significance of using lignin-derived aromatic hydrocarbons as a distinctive biomass source.publishersversionpublishe

Screening of Phaeodactylum tricornutum extracts regarding their bioactive and functional properties

The expanding interest in addressing a more sustainable and eco-friendlier product development regarding the problem of ecological preservation results in a growing community search for bioactive natural-based formulations. Microalgae extracts potential for their interesting bioactive properties has been widely recognized, with antioxidant activity accounting for a major application in cosmetics, pharmaceutics and nutrition fields, due to its health-promoting effects. Moreover, microalgae generally contain large amounts of structural biopolymers, which might possibly display interesting rheological properties. This work was designed to enhance microalgae potential biotechnology exploration by attaining at least two different main fractions, namely with bioactive and texturizing functions. Phaeodactylum tricornutum was used under a biorefinery concept, by performing extractions with several solvent systems with a wide polarity spectrum. Previous work enhanced this microalgae species potential as an antioxidant agent, regardless of the antioxidant quantification method used, when compared to Nannochloropsis oceanica and Chlorella vulgaris extracts. P. tricornutum powdered biomass was extracted (4% dry weight) using water or hydroethanolic mixtures (25-96%) under same conditions of extraction, namely, over one hour at three different temperatures: 40ºC, 60ºC and 80ºC. All extracts were screened for their bioactive potential by three different antioxidant activity measurement assays: FRAP, ABTS and DPPH, as well as chemical characterized regarding their phenolic and pigment content. Lipidic fraction was evaluated for ethanol 25%, 50% and 96% extracts. Rheological properties and emulsifying capacity and stability were determined for water and ethanol 25% extracts, while protein and carbohydrate content were also assessed. Overall, findings from this study suggest that P. tricornutum extracts have a great potential for biotechnology purposes: aqueous extracts were particularly interesting for their functional properties while bioactive properties were more relevant for the ethanolic extracts. These may due to a higher protein and carbohydrate fraction present in more aqueous extracts. On the other hand, extracts with higher concentration of ethanol evidenced a greater amount of pigments, phenolics and lipids. In this manner, further studies should be fulfilled in order to explore their application in natural-based product formulation.This work was supported by the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2020 unit. This study has also received funding from the European Fund for Regional Development (FEDER), COMPETE 2020 – Competitiveness and Internationalization Operational Program (Portugal 2020) and the European Regional Development Fund (Algarve 2020 and Lisboa 2020), under the scope of the project AlgaValor (grant agreement nº POCI-01-0247-FEDER-035234; LISBOA-01-0247-FEDER-035234; ALG-01-0247-FEDER-035234).info:eu-repo/semantics/publishedVersio

Screening of Phaeodactylum tricornutum extracts regarding theirbioactive and functional properties

The expanding interest in addressing a more sustainable and eco-friendlier product development regarding the problem of ecological preservation results in a growing community search for bioactive natural-based formulations. Microalgae extracts potential for their interesting bioactive properties has been widely recognized, with antioxidant activity accounting for a major application in cosmetics, pharmaceutics and nutrition fields, due to its health-promoting effects. Moreover, microalgae generally contain large amounts of structural biopolymers, which might possibly display interesting rheological properties. This work was designed to enhance microalgae potential biotechnology exploration by attaining at least two different main fractions, namely with bioactive and texturizing functions. Phaeodactylum tricornutum was used under a biorefinery concept, by performing extractions with several solvent systems with a wide polarity spectrum. Previous work enhanced this microalgae species potential as an antioxidant agent, regardless of the antioxidant quantification method used, when compared to Nannochloropsis oceanica and Chlorella vulgaris extracts. P. tricornutum powdered biomass was extracted (4% dry weight) using water or hydroethanolic mixtures (25-96%) under same conditions of extraction, namely, over one hour at three different temperatures: 40ºC, 60ºC and 80ºC. All extracts were screened for their bioactive potential by three different antioxidant activity measurement assays: FRAP, ABTS and DPPH, as well as chemical characterized regarding their phenolic and pigment content. Lipidic fraction was evaluated for ethanol 25%, 50% and 96% extracts. Rheological properties and emulsifying capacity and stability were determined for water and ethanol 25% extracts, while protein and carbohydrate content were also assessed. Overall, findings from this study suggest that P. tricornutum extracts have a great potential for biotechnology purposes: aqueous extracts were particularly interesting for their functional properties while bioactive properties were more relevant for the ethanolic extracts. These may due to a higher protein and carbohydrate fraction present in more aqueous extracts. On the other hand, extracts with higher concentration of ethanol evidenced a greater amount of pigments, phenolics and lipids. In this manner, further studies should be fulfilled in order to explore their application in natural-based product formulation.This work was supported by the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2020 unit. This study has also received funding from the European Fund for Regional Development (FEDER), COMPETE 2020 – Competitiveness and Internationalization Operational Program (Portugal 2020) and the European Regional Development Fund (Algarve 2020 and Lisboa 2020), under the scope of the project AlgaValor (grant agreement nº POCI-01-0247-FEDER-035234; LISBOA-01-0247-FEDER-035234; ALG-01-0247-FEDER-035234).info:eu-repo/semantics/publishedVersio

Application of bioelectrical impedance analysis in prediction of light kid carcass and muscle chemical composition

Carcass data were collected from 24 kids (average live weight of 12.5±5.5 kg; range 4.5 to 22.4 kg) of Jarmelista Portuguese native breed, to evaluate bioelectrical impedance analysis (BIA) as a technique for prediction of light kid carcass and muscle chemical composition. Resistance (Rs, Ω) and reactance (Xc, Ω), were measured in the cold carcasses with a single frequency bioelectrical impedance analyzer and, together with impedance (Z, Ω), two electrical volume measurements (VolA and VolB, cm2/Ω), carcass cold weight (CCW), carcass compactness and several carcass linear measurements were fitted as independent variables to predict carcass composition by stepwise regression analysis. The amount of variation explained by VolA and VolB only reached a significant level (P<0.01 and P<0.05, respectively) for muscle weight, moisture, protein and fat-free soft tissue content, even so with low accuracy, with VolA providing the best results (0.326⩽R 2⩽0.366). Quite differently, individual BIA parameters (Rs, Xc and Z) explained a very large amount of variation in dissectible carcass fat weight (0.814⩽R 2⩽0.862; P<0.01). These individual BIA parameters also explained a large amount of variation in subcutaneous and intermuscular fat weights (respectively 0.749⩽R 2⩽0.793 and 0.718⩽R 2⩽0.760; P<0.01), and in muscle chemical fat weight (0.663⩽R 2⩽0.684; P<0.01). Still significant but much lower was the variation in muscle, moisture, protein and fat-free soft tissue weights (0.344⩽R 2⩽0.393; P<0.01) explained by BIA parameters. Still, the best models for estimation of muscle, moisture, protein and fat-free soft tissue weights included Rs in addition to CCW, and accounted for 97.1% to 99.8% (P<0.01) of the variation observed, with CCW by itself accounting for 97.0% to 99.6% (P<0.01) of that variation. Resistance was the only independent variable selected for the best model predicting subcutaneous fat weight. It was also selected for the best models predicting carcass fat weight (combined with carcass length, CL; R 2=0.943; P<0.01) and intermuscular fat weight (combined with CCW; R 2=0.945; P<0.01). The best model predicting muscle chemical fat weight combined CCW and Z, explaining 85.6% (P<0.01) of the variation observed. These results indicate BIA as a useful tool for prediction of light kids' carcass composition.This work was supported by the Portuguese Science and Technology Foundation (FCT) under the Project PEst-OE/AGR/UID/CVT/00772/2013.info:eu-repo/semantics/publishedVersio

Utilization of bioelectrical impedance to predict intramuscular fat and physicochemical traits of the beef longissimus thoracis et lumborum muscle

The bioelectrical impedance analysis (BIA) is a non-destructive technique that has been successfully used to assess the body and carcass composition of farm species. This study aimed to predict intramuscular fat (IMF) and physicochemical traits in the longissimus thoracis et lumborum muscle (LM) of beef, using BIA. These traits were evaluated in LM samples of 52 crossbred heifer carcasses. The BIA was performed in LM, using a 50 Hz frequency high precision impedance converter system. A correlation analysis of the studied variables was performed. Then a stepwise with a k-folds cross validation procedure was used to modelling the prediction of IMF and physicochemical traits from BIA parameters (24.5%CV47.3%). Wide variation was found for IMF and BIA parameters. In general, correlations of BIA parameters with IMF and physicochemical traits were moderate to high and were similar for all BIA parameters (ô0.50r0.50 only for total pigments, a∗ and pH48). It was possible to predict IMF and physicochemical traits from BIA. The best fit explained 79.3% of the variation in IMF, while for physicochemical traits the best fits were for sarcomere length and shear force (64.4% and 60.5%, respectively). The results confirmed the potential of BIA for objective measurement of meat quality.This work was supported by the project UIDB/CVT/00772/2020 funded by the Fundação para a Ciência e Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

Prediction of apparent digestibility of hays from natural pastures of the Northeast region of Portugal

In the Northeast region of Portugal hays from natural pastures are traditionally used as the main feed during the period of drought and the evaluation of its nutritive value is essential. The aim of this study was to predict the apparent organic matter digestibility (OMD) of 21 hays from natural pastures based on chemical composition, pepsin-cellulase solubility of organic matter (OMS) and in vitro organic matter digestibility. Chemical composition of hays showed a wide range of values and acid detergent lignin (ADL) was the component that presented the highest variation (CV = 18.4%). The OMD varied between 516 and 658 g/kg OM. The best single OMD predictor was OMS (RSD = 2.8%, R2 = 0.52, P<0.001). Using multiple regression to predict OMD, the variables included in the model were OMS and ADL (OMD = 21.51 + 0.94 OMS – 0.83 ADL; RSD = 2.75%; R2 = 0.54; P<0.0001). According to principal component analysis (PCA) hays were divided in 3 groups and the multiple regression established for the larger group of hays (n=10) was: OMD = 4.13 + 0.85 OMS – 1.03 ADL; RSD = 2.13%, R2 = 0.77, P<0.0001. The OMS method was superior to chemical composition and to the in vitro rumen fluid method in predicting OMD of hays from natural pastures. Results from PCA suggested that it may be useful to group these hays according to its chemical composition to accurately predict OMD

Biological and chemical valorization potential of portuguese seaweeds: Ulva rigida, Gracilaria sp. and Fucus vesiculosus

info:eu-repo/semantics/publishedVersio

Sheep whole body composition predicted by in vivo real time ultrasound measurements

Accurate measurement of changes in body composition and in the energy content of live animals is crucial to understand the responses to the intake of nutrients. Despite the accuracy of the serial slaughter technique in determining body composition, it is very expensive and comparisons within an animal became impossible thus the need for an accurate method to predict body composition in the live animal is obvious for the biological efficiency studies. This work aimed to establish equations to estimate in vivo whole empty body chemical composition of sheep using real time ultrasound CRTU) measurements