47 research outputs found
Lying down with protective setae as an alternative antipredator defence in a non-webbing spider mite
Establishment of cell suspension culture in Marchantia linearis Lehm & Lindenb. for the optimum production of flavonoids
Polymerization of 4-Hydroxyphenyl .ALPHA.-Glucoside and 4-Hydroxyphenyl .BETA.-Glucoside Catalyzed by Horseradish Peroxidase
Dual effects of N-acetyl-l-cysteine dependent on NQO1 activity: Suppressive or promotive of 9,10-phenanthrenequinone-induced toxicity
A typical antioxidant, N-acetyl-L-cysteine (NAC) generally protects cells from oxidative damage induced by reactive oxygen species (ROS). 9,10-Phenanthrenequinone (9,10-PQ), a major quinone in diesel exhaust particles, produces ROS in redox cycling following two-electron reduction by NAD(P)H:quinone oxidoreductase 1 (NQO1), which has been considered as a cause of its cyto- and genotoxicity. In this study, we show that NAC unexpectedly augments the toxicity of 9,10-PQ in cells with low NQO1 activity. In four human skin cell lines, the expression and the activity of NQO1 were lower than in human adenocarcinoma cell lines, A549 and MCF7. In the skin cells, the cytotoxicity of 9,10-PQ was significantly enhanced by addition of NAC. The formation of DNA double strand breaks accompanying phosphorylation of histone H2AX, was also remarkably augmented. On the other hand, the cyto- and genotoxicity were suppressed by addition of NAC in the adenocarcinoma cells. Two contrasting experiments: overexpression of NQO1 in CHO-K1 cells which originally expressed low NQO1 levels, and knock-down of NQO1 in the adenocarcinoma cell line A549 by transfection of RNAi, also showed that NAC suppressed 9,10-PQ-induced toxicity in cell lines expressing high NQO1 activity and enhanced it in cell lines with low NQO1 activity. The results suggested that dual effects of NAC on the cyto- and genotoxicity of 9,10-PQ were dependent on tissue-specific NQO1 activity
Polyunsaturated fatty acids production by solid-state fermentation on polyurethane foam by Mortierella alpina
Polyunsaturated fatty acids (PUFAs) are essential in healthy diets and their production is extremely important. Natural sources of PUFAs includes animal and aquatic products such as marine fish oil, however there are several limitations such as the decrease of fish stocks throughout the world. Thus, microbial oils are a preferable source of PUFAs. Herein, it was studied the production of PUFAs by Mortierella alpina under solidstate fermentation (SSF) using polyurethane foam as inert substrate and synthetic medium or lignocellulosic hydrolysate as source of C, N and other nutrients. Several parameters of fermentation conditions were evaluated as carbon source, inductors addition, ratio C/N and temperature.
The highest amount of total PUFAs per mass of solid (535.41 ±24.12 mg/g), linoleic acid (129.66 ±5.84 mg/g) and linoleic acid (401.93 ±18.10 mg/g) were produced when the culture medium contained 20 g/L glucose, 10% (w/v) linseed oil, the C/N ratio was adjusted to 25 and the incubation temperature was 25 °C for 3days decreasing to 16 °C on the remaining 4days of fermentation. In addition, a hemicellulosic hydrolysate can be used as lowcost substrate to produce PUFAs, although the production was lower than the achieved with synthetic medium. SSF showed an interesting technology for microbial PUFAs production.José Manuel Salgado was supported by grant CEB/N2020— INV/01/2016 from Project “BIOTECNORTE—Underpinning Biotechnology to foster the north of Portugal bioeconomy” (NORTE 01-0145-FEDER-000004). This work was supported by the R&D&I project “Development of innovative sustainable protein and omega-3
rich feedstuffs for aquafeeds, from local agro-industrial by-products”, reference POCI-01-0145-FEDER-030377, funded by European Regional Development Fund (ERDF). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTec-Norte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio
358 MICROINSEMINATION USING MALE GERM CELLS FROM EPIDIDYMIDES AND TESTES STORED IN FREEZERS WITHOUT CRYOPROTECTANT
Calcification responses of symbiotic and aposymbiotic corals to near-future levels of ocean acidification
Increasing the acidity of ocean waters will directly threaten calcifying marine organisms such as
reef-building scleractinian corals, and the myriad of species that rely on corals for protection
and sustenance. Ocean pH has already decreased by around 0.1 pH units since the beginning of
the industrial revolution, and is expected to decrease by another 0.2–0.4 pH units by 2100. This
study mimicked the pre-industrial, present, and near-future levels of <i>p</i>CO<sub>2</sub> using a precise
control system (± 5% <i>p</i>CO<sub>2</sub>), to assess the impact of ocean acidification on the calcification of
recently settled primary polyps of <i>Acropora digitifera</i>, both with and without symbionts, and
adult fragments with symbionts. The increase in <i>p</i>CO<sub>2</sub> of ~100 μatm between the pre-industrial
period and the present had more effect on the calcification rate of adult <i>A. digitifera</i> than the
anticipated future increases of several hundreds of micro-atmospheres of <i>p</i>CO<sub>2</sub>. The primary
polyps with symbionts showed higher calcification rates than primary polyps without symbionts,
suggesting that: (i) primary polyps housing symbionts are more tolerant to near-future ocean
acidification than organisms without symbionts, and (ii) corals acquiring symbionts from the
environment (i.e., broadcasting species) will be more vulnerable to ocean acidification than
corals that maternally acquire symbionts