Papers by Cecilia Faraloni
Abstract The current need for alternative source of green energy have brought the interest on the... more Abstract The current need for alternative source of green energy have brought the interest on the biological hydrogen production. Molecular H2 can be produced by different biological processes based on the utilization of light energy, carried out by some photosynthetic microorganisms, like microalgae, able to switch their metabolism from oxygenic photosynthesis to H2 evolution. Interestingly, microalgae, as Chlamydomonas reinhardtii, are able to utilize their internal substrate, as carbohydrates and proteins, to drive the H2 production process. They also possess the capability to utilize external source of organic compounds present in wastewaters, both for their growth and as substrate for H2 production, as C. reinhardtii and Chlorella. In this respect, the microalgal H2 production can be considered a very current topic well fitting in the frame of the concept of a bioeconomy, considering both the renewable energy production idea and recovery of waste material to be converted into fuel.
Lecture notes in networks and systems, 2023
Almond beverages are gaining ever-increasing consumer preference in the growing market of non-alc... more Almond beverages are gaining ever-increasing consumer preference in the growing market of non-alcoholic vegetable beverages, ranking in first place among oilseed-based drinks, mainly due to the perceived healthy benefits. However, the high cost of the raw material, time and energy consuming pre-treatments such as soaking, blanching and peeling, and post-treatments such as thermal sterilization, leading also to the loss of valuable macronutrients and micronutrients, hinder the sustainability, affordability and spread of almond beverages. Hydrodynamic cavitation processes were applied, as a single-unit operation, to the extraction in water of almond skinless kernels in the form of flour and fine grains, and to whole almond seeds in the form of coarse grains, up to high concentrations. The results showed full compliance with a high-end commercial product and with the expected levels based on the properties of the raw materials. The concentrated extract obtained from whole almond seeds showed a comparatively much higher antiradical activity, likely due to the contribution of the almond kernel skin. In conclusion, hydrodynamic cavitation could represent a convenient alternative processing route to the production of conventional and new integral almond beverages, avoiding multiple and costly technological steps, while affording fast production cycles of potentially healthier beverages.
Elsevier eBooks, 2017
Abstract Two biological methods for hydrogen production involving microalgae are revised. In one ... more Abstract Two biological methods for hydrogen production involving microalgae are revised. In one method, microalgae use the light energy to produce hydrogen from water. In the second one, bacteria capable of fermenting the carbohydrates (either structural or stored in the microalgal cell wall) are utilized to produce hydrogen. Different approaches for using direct and indirect biophotolysis and strategies for using microalgae as feedstock for dark fermentation are presented and discussed. Finally, a life cycle assessment on hydrogen production by these two methods is used to identify the technological bottlenecks, detecting the weaknesses and focusing the research efforts needed.
Springer eBooks, Oct 5, 2018
Photochemical and Photobiological Sciences, Apr 10, 2023
Phycobiliproteins, carotenoids and fucoxanthin are photosynthetic pigments extracted from microal... more Phycobiliproteins, carotenoids and fucoxanthin are photosynthetic pigments extracted from microalgae and cyanobacteria with great potential biotechnological applications, as healthy food colorants and cosmetics. Phycocyanin possesses a brilliant blue color, with fluorescent properties making it useful as a reagent for immunological essays. The most important source of phycocyanin is the cyanobacterium Arthrospira platensis, however, recently, the Rhodophyta Galdieria sulphuraria has also been identified as such. The main obstacle to the commercialization of phycocyanin is represented by its chemical instability, strongly reducing its shelf-life. Moreover, the high level of purity needed for pharmaceutical applications requires several steps which increase both the production time and cost. Microalgae (Chlorella, Dunaliella, Nannochloropsis, Scenedesmus) produce several light harvesting carotenoids, and are able to manage with oxidative stress, due to their free radical scavenging properties, which makes them suitable for use as source of natural antioxidants. Many studies focused on the selection of the most promising strains producing valuable carotenoids and on their extraction and purification. Among carotenoids produced by marine microalgae, fucoxanthin is the most abundant, representing more than 10% of total carotenoids. Despite the abundance and diversity of fucoxanthin producing microalgae only a few species have been studied for commercial production, the most relevant being Phaeodactylum tricornutum. Due to its antioxidant activity, fucoxanthin can bring various potential benefits to the prevention and treatment of lifestyle-related diseases. In this review, we update the main results achieved in the production, extraction, purification, and commercialization of these important pigments, motivating the cultivation of microalgae as a source of natural pigments.
Bioresource Technology Reports, Jun 1, 2022
Authorea (Authorea), May 21, 2021
This a preprint and has not been peer reviewed. Data may be preliminary.
Biotechnology and Bioengineering, Aug 6, 2021
In situ chlorophyll a fluorescence measurements were applied to monitor changes in the photochemi... more In situ chlorophyll a fluorescence measurements were applied to monitor changes in the photochemical variables of Nannochloropsis oceanica cultures under nitrogen‐deplete and nitrogen‐replete (control) conditions. In addition, growth, lipid, fatty acid, and pigment contents were also followed. In the control culture, growth was promoted along with pigment content, electron transport rate (ETR), and polyunsaturated fatty acids, while total lipid content and fatty acid saturation level diminished. Under nitrogen‐deplete conditions, the culture showed a higher de‐epoxidation state of the xanthophyll cycle pigments. Fast transients revealed a poor processing efficiency for electron transfer beyond QA, which was in line with the low ETR due to nitrogen depletion. Lipid content and the de‐epoxidation state were the first biochemical variables triggered by the change in nutrient status, which coincided with a 20% drop in the in situ effective quantum yield of PSII (ΔF’/Fm'), and a raise in the Vj measurements. A good correlation was found between the changes in ΔF’/Fm' and lipid content (r = −0.96, p < 0.01). The results confirm the reliability and applicability of in situ fluorescence measurements to monitor lipid induction in N. oceanica.
Almond beverages are gaining ever-increasing consumer preference in the growing market of non-alc... more Almond beverages are gaining ever-increasing consumer preference in the growing market of non-alcoholic vegetable beverages, ranking in first place among oilseed-based drinks, mainly due to the perceived healthy benefits. However, the high cost of the raw material, time and energy consuming pre-treatments such as soaking, blanching and peeling, and post-treatments such as thermal sterilization, leading also to the loss of valuable macronutrients and micronutrients, hinder the sustainability, affordability and spread of almond beverages. Hydrodynamic cavitation processes were applied, as a single-unit operation, to the extraction in water of almond skinless kernels in the form of flour and fine grains, and to whole almond seeds in the form of coarse grains, up to high concentrations. The results showed full compliance with a high-end commercial product and with the expected levels based on the properties of the raw materials. The concentrated extract obtained from whole almond seeds ...
Antioxidants, 2022
The genus Iris from the Iridaceae family consists of more than 262 recognized species. It is an o... more The genus Iris from the Iridaceae family consists of more than 262 recognized species. It is an ornamental and medicinal plant widely distributed in the Northern Hemisphere. Iris species convey a long history as valuable traditional drugs with a wide variety of applications in various cultures, having been recorded since medieval times. Currently, Iris spp. still find application in numerous fields, including cosmetics, pharmaceutics and the food industry. Moreover, many of their empirical uses have been validated by in vitro and in vivo studies, showing that Iris spp. exhibit potent antioxidant, anticancer, anti-inflammatory, hepatoprotective, neuroprotective and anti-microbial properties. Phytochemicals investigations have revealed that the plant extracts are rich in phenolic compounds, especially flavonoids and phenolic acids. As such, they constitute a promising lead for seeking new drugs with high susceptibilities towards various health issues, particularly oxidative-stress-rel...
Journal of Plant Biochemistry and Biotechnology, 2021
The green alga Haematococcus pluvialis is able to produce and accumulate large amounts of astaxan... more The green alga Haematococcus pluvialis is able to produce and accumulate large amounts of astaxanthin under stress conditions. In this study H. pluvialis was exposed to different concentrations of cyanide (0, 6, 9 and 12 µM), in two-time periods (treatmenton = 14 days and pre-treatment = 7 days) to compare the changes on growth and biochemical parameters in green and red stages. In green stage, cyanide treatment had not significant effect on dry weight, chlorophyll a and protein content, but increased the amount of chlorophyll b, carotenoid and carbohydrate. In addition, an increase in carbohydrate and carotenoid content was observed in cyanide treatment. Cyanide pre-treatment at low concentration increased and at higher concentrations declined all measured parameters in the green and red stage. Cyanide treatment had better performance in increasing the amount of carotenoids in red cell. The amount of astaxanthin significantly increased in treated and pre-treated algae with cyanide. Pre-treatment with cyanide due to increase in growth, had better influence in enhancing astaxanthin content. These results show that H. pluvialis offer potential to phytoremediation of cyanide and in low concentrations, it can induce astaxanthin accumulation in H. pluvialis.
International Journal of Hydrogen Energy, 2015
Biological hydrogen production is being evaluated for use as fuel, since it is a promising substi... more Biological hydrogen production is being evaluated for use as fuel, since it is a promising substitute for carbonaceous fuels owing to its high conversion efficiency and high specific energy content. The microalga Chlamydomonas reinhardtii when grown under sulfur-deprived conditions, switches the metabolism toward the production of hydrogen. A better understandings of physiological and biochemical changes occurring during each phases of the process, represents a prerequisite to enhance the hydrogen output. The aim of this work was to study whether the activation of enzymes of the antioxidant defense system, such as catalase (CAT), ascorbate peroxidase (APOX) and guaiacol peroxidase (GPOX), takes place during the entire process of hydrogen production by C. reinhardtii CC 124. Kinase activities present in the crude protein extract and the mitotic specific ones associated with CKS1 protein were assayed to determine how the conditions leading to hydrogen production affected the activities of mitotic and growth associated kinases. We present evidences that oxidative stress enzymes are active during the entire hydrogen production process, besides their activities are higher in the anoxic phase. Stress condition during hydrogen photoproduction provoked at least partial cell cycle arrest leading to block of mitosis and cell division. These findings are in line with the known down-regulation or block of cell cycle related processes in stressed or starved cells.
Tannins, extracted from various plant sources, are worldwide commodities used in several differen... more Tannins, extracted from various plant sources, are worldwide commodities used in several different fields, including leather manufacturing and the production of bio-based adhesives, with emerging use in technical, environmental, food and feed sectors, pharmacology. Due to increasing market demand, few emerging techniques were proposed besides the usual hot water extraction usually performed under pressurized conditions. For the first time, hydrodynamic cavitation, an emerging and straightforwardly scalable green extraction technique, was applied to the extraction of tannins from chestnut wood waste in water only and at room pressure, without any pretreatment of the raw material. Promising performances were shown based on tests carried out from room temperature up to 100°C. Extraction rates close to 300 mg of tannin per gram of chestnut wood material (dry basis) were observed, as well as high levels of the antioxidant activity of the obtained extract (IC50 about 10 µg of chestnut woo...
Water
This study aimed to investigate the potential use of the microalgae Chlorella sorokiniana and Sce... more This study aimed to investigate the potential use of the microalgae Chlorella sorokiniana and Scenedesmus quadricauda for the bioremediation of olive mill wastewater (OMW), which is a major environmental issue and a waste product of olive oil production. The study investigated the effects of different dilutions (10% and 50%) of OMW on the growth of the microalgae and their ability to remove the phenolic component hydroxytyrosol (OH-Tyr) and enhance their antioxidant properties. The results indicated that, although the growth on OMW was not enhanced, both microalgae strains were able to remove OH-Tyr from OMW, with Chlorella sorokiniana showing higher removal efficiency than Scenedesmus quadricauda. Moreover, the antioxidant activity of the microalgal extracts increased after 96 h of exposure to OMW. These findings suggest that microalgae-based treatment of OMW could be a promising approach for the bioremediation of this waste product and the production of value-added products. Overa...
Frontiers in Pharmacology, Apr 20, 2023
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Papers by Cecilia Faraloni