Chlorella vulgaris phycoremediation at low Cu+2 contents: Proteomic profiling of microalgal metabolism related to fatty acids and CO2 fixation.

The aim of this work was to correlate metabolic changes with copper ions (Cu+2) bioremediation by microalgae C. vulgaris 097 CCMA-UFSCar at low Cu+2 content. The metabolic effects include proteome changes related to fatty acid biosynthesis (value-added product) and carbon fixation (climate change mitigation). Cu+2, even at low concentration, showed a significant negative impact on C. vulgaris growth. The microalgal bioremediation reached 100, 74, 38 and 26% for Cu+2 content at 0.1; 0.3; 0.6 and 0.9 mg L-1, respectively. Regarding proteomics, the numbers of proteins reduced (≈37%) from 581 proteins (control) to 369 proteins (0.9 mg of Cu+2 L-1) compared to control. The microalgal CO2 fixation is strictly related to the Calvin cycle, particularly phase 1, in which ribulose bisphosphate carboxylase large chain (RuBisCO) produces two phosphoglycerate molecules from CO2 and ribulose 1,5-bisphosphate. Then, phosphoglycerate can be metabolically reduced into glucose. When compared to control, the RuBisCO was underexpressed (≈50%). Similar changes in proteomic profiling of metabolism-related to fatty acid biosynthesis was observed. Nevertheless, no protein was found for the cultivation at 0.9 mg of Cu+2 L-1. Thus, the analysis of C. vulgaris proteomic data indicated that even at low concentration, Cu+2 lead to drastic metabolic changes.

Influence of rye flour enzymatic biotransformation on the antioxidant capacity and transepithelial transport of phenolic acids.

Phenolic acids have been reported to play a role on the antioxidant activity and other important biological activities. However, as most polyphenolics in food products are either bound to cellular matrices or present as free polymeric forms, the way they are absorbed has not been totally clear until now. Hydrolytic enzymes may act to increase functionalities in polyphenolic-rich foods, enhancing the bioaccessibility of phenolic compounds and minerals from whole grains. The aim of this study was to evaluate the action of tannin acyl hydrolase (tannase) on the total phenols, phenolic acid profile, antioxidant capacity and in vitro bioaccessibility of phenolic acids found in whole rye flour (RF). Besides increasing total phenols and the antioxidant capacity, tannase treatment increased the amounts of ferulic, sinapic and vanillic acids identified in RF, evidencing a new type of feruloyl esterase catalytic action of tannase. Vanillic and sinapic acids in tannase-treated whole rye flour (RFT) were higher than RF after in vitro gastrointestinal digestion, and higher amounts of transported vanillic acid through the Caco-2 monolayer were detected in RFT. However, the bioaccessibility and the transport efficiency of RF phenolic acids were higher than RFT. Underutilized crops like rye and rye-derived products may be an important source of phenolic acids. The tannase biotransformation, even influencing the total phenolics and antioxidant capacity of RF, did not increase the bioaccessibility of phenolic acids under the experimental conditions of this study.

Chemical inhibition of the contaminant Lactobacillus fermentum from distilleries producing fuel bioethanol

The purpose of this study was to determine the Minimum Inhibitory Concentration (MIC) of pure or mixed chemicals for Saccharomyces cerevisiae and Lactobacillus fermentum in the samples isolated from distilleries with serious bacterial contamination problems. The biocides, which showed the best results were: 3,4,4' trichlorocarbanilide (TCC), tested at pH 4.0 (MIC = 3.12 mg/l), TCC with benzethonium chloride (CBe) at pH 6.0 (MIC = 3.12 mg/l) and TCC mixed with benzalkonium chloride (CBa) at pH 6.0 (MIC = 1.53 mg /l). If CBa was used in sugar cane milling in 1:1 ratio with TCC, a 8 times reduction of CBa was possible. This formulation also should be tested in fermentation steps since it was more difficult for the bacterium to develop resistance to biocide. There was no inhibition of S. cerevisiae and there were only antibiotics as an option to bacterial control of fuel ethanol fermentation by S. cerevisiae.

Effect of annatto seed and coriander leaves as natural antioxidants in fish meatballs during frozen storage.

UNLABELLED: The effects of annatto (0.1 g/100g) and coriander (0.5 g/100g) were assessed against lipid oxidation in white hake meatballs cooked in boiling water (95 ± 1 °C) for 30 min and stored at -18 °C for 120 d. The fatty acids (FA) and the nutritional quality, cholesterol, cholesterol oxides, thiobarbituric acid reactive substances (TBARS) values, and conjugated dienes were analyzed to follow the course of oxidation. Annatto and coriander were efficient in the control of lipid oxidation, also preserving the essential FA. At 120 d of storage, the eicosapentaenoic acid (EPA) concentration decreased respectively by 43%, 32%, 12%, and 9% in the control, coriander, annatto, and annatto + coriander patties. For docosahexaenoic acid (DHA), these concentrations decreased, respectively, 44%, 30%, 11%, and 7%, revealing a probable synergistic effect among the antioxidant compounds present in both spices. On the other hand, annatto and coriander were not able to act protecting the meatballs against lipid oxidation when they were cooked, also not exerted any effect in the cholesterol oxidation. PRACTICAL APPLICATION: Spices, especially coriander and annatto, can be an alternative to substitute synthetic additives with antioxidants to prevent loss of important unsaturated fatty acids (UFA) in fish meatballs during frozen storage for 120 d. The maximum effect was observed when 0.5% coriander and 0.1% annatto were used in combination. Cooking did not induce the formation of cholesterol oxides, compounds that can cause more health damages than cholesterol itself; however, during storage the cholesterol oxides levels presented a little increase regardless of spice addition.