Macroalgae-A Sustainable Source of Chemical Compounds with Biological Activities.

Nowadays, one of the most important research directions that concerns the scientific world is to exploit the earth's resources in a sustainable way. Considering the increasing interest in finding new sources of bioactive molecules and functional products, many research studies focused their interest on demonstrating the sustainability of exploiting marine macroalgal biomass as feedstock for wastewater treatment and natural fertilizer, conversion into green biofuels, active ingredients in pharmaceutical and nutraceutical products, or even for the production of functional ingredients and integration in the human food chain. The objective of the present paper was to provide an overview on the recent progress in the exploitation of different macroalgae species as a source of bioactive compounds, mainly emphasizing the latter published data regarding their potential bioactivities, health benefits, and industrial applications.

Cerium Oxide Nanoparticles and Their Efficient Antibacterial Application In Vitro against Gram-Positive and Gram-Negative Pathogens.

In this study, the antibacterial activity of cerium oxide nanoparticles on two Gram-negative and three Gram-positive foodborne pathogens was investigated. CeO2 nanoparticles (CeO2 nps) were synthesized by a Wet Chemical Synthesis route, using the precipitation method and the Simultaneous Addition of reactants (WCS-SimAdd). The as-obtained precursor powders were investigated by thermal analysis (TG-DTA), to study their decomposition process and to understand the CeO2 nps formation. The composition, structure, and morphology of the thermally treated sample were investigated by FTIR, Raman spectroscopy, X-ray diffraction, TEM, and DLS. The cubic structure and average particle size ranging between 5 and 15 nm were evidenced. Optical absorption measurements (UV-Vis) reveal that the band gap of CeO2 is 2.61 eV, which is smaller than the band gap of bulk ceria. The antioxidant effect of CeO2 nps was determined, and the antibacterial test was carried out both in liquid and on solid growth media against five pathogenic microorganisms, namely Escherichia coli, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. Cerium oxide nanoparticles showed growth inhibition toward all five pathogens tested with notable results. This paper highlights the perspectives for the synthesis of CeO2 nps with controlled structural and morphological characteristics and enhanced antibacterial properties, using a versatile and low-cost chemical solution method.

Edible Films and Coatings Functionalization by Probiotic Incorporation: A Review.

Edible coatings and films represent an alternative packaging system characterized by being more environment- and customer-friendly than conventional systems of food protection. Research on edible coatings requires multidisciplinary efforts by food engineers, biopolymer specialists and biotechnologists. Entrapment of probiotic cells in edible films or coatings is a favorable approach that may overcome the limitations linked with the use of bioactive compounds in or on food products. The recognition of several health advantages associated with probiotics ingestion is worldwide accepted and well documented. Nevertheless, due to the low stability of probiotics in the food processing steps, in the food matrices and in the gastrointestinal tract, this kind of encapsulation is of high relevance. The development of new and functional edible packaging may lead to new functional foods. This review will focus on edible coatings and films containing probiotic cells (obtaining techniques, materials, characteristics, and applications) and the innovative entrapment techniques use to obtained such packaging.

L (+)-lactic acid production by pellet-form Rhizopus oryzae NRRL 395 on biodiesel crude glycerol.

BACKGROUND: Given its availability and low price, glycerol derived from biodiesel industry has become an ideal feedstock for the production of fuels and chemicals. A solution to reduce the negative environmental problems and the cost of biodiesel is to use crude glycerol as carbon source for microbial growth media in order to produce valuable organic chemicals. In the present paper, crude glycerol was used as carbon substrate for production of L (+)-lactic acid using pelletized fungus R. oryzae NRRL 395 on batch fermentation. More, the experiments were conducted on media supplemented with inorganic nutrients and lucerne green juice. RESULTS: Crude and pure glycerols were first used to produce the highest biomass yield of R. oryzae NRRL 395. An enhanced lactic acid production then followed up using fed-batch fermentation with crude glycerol, inorganic nutrients and lucerne green juice. The optimal crude glycerol concentration for cultivating R. oryzae NRRL 395 was 75 g l(-1), which resulted in a fungal biomass yield of 0.72 g g(-1) in trial without lucerne green juice addition and 0.83 g g(-1) in trial with lucerne green juice. The glycerol consumption rate was 1.04 g l(-1) h(-1) after 48 h in trial with crude glycerol 75 g l(-1) while in trial with crude glycerol 10 g l(-1) the lowest rate of 0.12 g l(-1) h(-1) was registered. The highest L (+)-lactic acid yield (3.72 g g(-1)) was obtained at the crude glycerol concentration of 75 g l(-1) and LGJ 25 g l(-1), and the concentration of lactic acid was approximately 48 g l(-1). CONCLUSIONS: This work introduced sustainable opportunities for L (+)-lactic acid production via R. oryzae NRRL 395 fermentation on biodiesel crude glycerol media. The results showed good fungal growth on crude glycerol at 75 g l(-1) concentration with lucerne green juice supplementation of 25 g l(-1). Lucerne green juice provided a good source of nutrients for crude glycerol fermentation, without needs for supplementation with inorganic nutrients. Crude glycerol and lucerne green juice ratio influence the L (+)-lactic acid production, increasing the lactate productivity with the concentration of crude glycerol.