Treatment of Agro-Food Wastewaters and Valuable Compounds Recovery by Column Sorption Runs

The use of microbial fuel cells (MFCs) is quickly spreading in the fields of bioenergy generation and wastewater treatment, as well as in the biosynthesis of valuable compounds for microbial electrolysis cells (MECs). MFCs and MECs have not been able to penetrate the market as economic feasibility is lost when their performances are boosted by nanomaterials. The nanoparticles used to realize or decorate the components (electrodes or the membrane) have expensive processing, purification, and raw resource costs. In recent decades, many studies have approached the problem of finding green synthesis routes and cheap sources for the most common nanoparticles employed in MFCs and MECs. These nanoparticles are essentially made of carbon, noble metals, and non-noble metals, together with a few other few doping elements. In this review, the most recent findings regarding the sustainable preparation of nanoparticles, in terms of syntheses and sources, are collected, commented, and proposed for applications in MFC and MEC devices. The use of naturally occurring, recycled, and alternative raw materials for nanoparticle synthesis is showcased in detail here. Several examples of how these naturally derived or sustainable nanoparticles have been employed in microbial devices are also examined. The results demonstrate that this approach is valuable and could represent a solid alternative to the expensive use of commercial nanoparticles.

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Impact of Environmental Factors on Stilbene Biosynthesis

Plants ◽

10.3390/plants10010090 ◽

2021 ◽

Vol 10 (1) ◽

pp. 90

Author(s):

Alessio Valletta ◽

Lorenzo Maria Iozia ◽

Francesca Leonelli

Keyword(s):

Environmental Factors ◽

Biosynthetic Pathway ◽

In Planta ◽

Organ Cultures ◽

Related Plant ◽

Valuable Compounds ◽

Stilbene Compounds ◽

Stilbene Biosynthesis ◽

Abiotic Environmental Factors

Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds.

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Synthesis of Biobased Phloretin Analogues: An Access to Antioxidant and Anti-Tyrosinase Compounds for Cosmetic Applications

Antioxidants ◽

10.3390/antiox10040512 ◽

2021 ◽

Vol 10 (4) ◽

pp. 512

Author(s):

Laurène Minsat ◽

Cédric Peyrot ◽

Fanny Brunissen ◽

Jean-Hugues Renault ◽

Florent Allais

Keyword(s):

Natural Products ◽

Consumer Demand ◽

Radical Scavenging ◽

Green Process ◽

Direct Extraction ◽

Low Concentration ◽

Cosmetic Formulations ◽

Valuable Compounds ◽

The Stability

The current cosmetic and nutraceutical markets are characterized by a strong consumer demand for a return to natural products that are less harmful to both the consumers and the environment than current petrosourced products. Phloretin, a natural dihydrochalcone (DHC) found in apple, has been widely studied for many years and identified as a strong antioxidant and anti-tyrosinase ingredient for cosmetic formulations. Its low concentration in apples does not allow it to be obtained by direct extraction from biomass in large quantities to meet market volumes and prices. Moreover, its remarkable structure prevents its synthesis through a green process. To overcome these issues, the synthesis of phloretin analogs appears as an alternative to access valuable compounds that are potentially more active than phloretin itself. Under such considerations, 12 chalcones (CHs) and 12 dihydrochalcones (DHCs) were synthesized through a green Claisen–Schmidt condensation using bio-based reagents. In order to evaluate the potential of these molecules, radical scavenging DPPH and anti-tyrosinase tests have been conducted. Moreover, the UV filtering properties and the stability of these analogs towards UV-radiations have been evaluated. Some molecules showed competitive antioxidant and anti-tyrosinase activities regarding phloretin. Two compounds in particular showed EC50 lower than phloretin, one chalcone and one dihydrochalcone.

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Nectar non-protein amino acids (NPAAs) do not change nectar palatability but enhance learning and memory in honey bees

Scientific Reports ◽

10.1038/s41598-021-90895-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Daniele Carlesso ◽

Stefania Smargiassi ◽

Elisa Pasquini ◽

Giacomo Bertelli ◽

David Baracchi

Keyword(s):

Amino Acids ◽

Learning And Memory ◽

Honey Bees ◽

Feeding Preference ◽

Memory Retention ◽

Floral Nectar ◽

Olfactory Conditioning ◽

Specific Memory ◽

Protein Amino Acids ◽

Valuable Compounds

AbstractFloral nectar is a pivotal element of the intimate relationship between plants and pollinators. Nectars are composed of a plethora of nutritionally valuable compounds but also hundreds of secondary metabolites (SMs) whose function remains elusive. Here we performed a set of behavioural experiments to study whether five ubiquitous nectar non-protein amino acids (NPAAs: β-alanine, GABA, citrulline, ornithine and taurine) interact with gustation, feeding preference, and learning and memory in Apis mellifera. We showed that foragers were unable to discriminate NPAAs from water when only accessing antennal chemo-tactile information and that freely moving bees did not exhibit innate feeding preferences for NPAAs. Also, NPAAs did not alter food consumption or longevity in caged bees over 10 days. Taken together our data suggest that natural concentrations of NPAAs did not alter nectar palatability to bees. Olfactory conditioning assays showed that honey bees were more likely to learn a scent when it signalled a sucrose reward containing either β-alanine or GABA, and that GABA enhanced specific memory retention. Conversely, when ingested two hours prior to conditioning, GABA, β-alanine, and taurine weakened bees’ acquisition performances but not specific memory retention, which was enhanced in the case of β-alanine and taurine. Neither citrulline nor ornithine affected learning and memory. NPAAs in nectars may represent a cooperative strategy adopted by plants to attract beneficial pollinators.

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Evaluation of olive mill waste as substrate for carotenoid production by Rhodotorula mucilaginosa

Bioresources and Bioprocessing ◽

10.1186/s40643-020-00341-7 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Carolina Ghilardi ◽

Paola Sanmartin Negrete ◽

Amalia Antonia Carelli ◽

Virginia Borroni

Keyword(s):

Liquid Fraction ◽

Added Value ◽

Organic Load ◽

Integral Approach ◽

Rhodotorula Mucilaginosa ◽

Total Sugars ◽

Carotenoid Production ◽

Total Sugar Concentration ◽

Valuable Compounds ◽

Olive Mill

Abstract The “alperujo” is a waste from the olive oil industry with great potential for valorization. It has a high organic load, with the presence of valuable compounds such as biophenols and sugars. The use of this waste can be thought of as a biorefinery from which different compounds of high added value can be obtained, whether they are present in the “alperujo” such as biophenols or can be generated from the “alperujo”. Therefore, the production of carotenoids by Rhodotorula mucilaginosa was evaluated using the liquid fraction of ‘alperujo’ (Alperujo Water, AW) or an aqueous extract (AE) of “alperujo” at different concentrations (5, 10, 20 and 30% w/V) as substrates. The AEs had an acidic pH, a total sugar concentration ranging from 1.6 to 7.6 g/L, a polyphenols content from 0.4 to 2.9 g/L and a significant amount of proteins (0.5–3 g/L). AW is similar in composition as 30% AE, but with a higher amount of total sugars. Rh. mucilaginosa was able to grow at the different mediums with consumption of glucose and fructose, a reduction in protein content and alkalinization of the medium. Maximum total carotenoid production (7.3 ± 0.6 mg/L) was achieved at AW, while the specific production was higher when the yeast grew at AW or at 30% AE (0.78 ± 0.06 and 0.73 ± 0.10 mg/g of biomass, respectively). Torulene and torularhodin were the main carotenoids produced. Polyphenol content did not change; thus, it is still possible to recover these compounds after producing carotenoids. These results demonstrate the feasibility of using alperujo-based mediums as cheap substrates to produce torularhodin and torulene and to include this bioprocess as a step in an integral approach for alperujo valorization.

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Genetic and Pre- and Postharvest Factors Influencing the Content of Antioxidants in Cucurbit Crops

Antioxidants ◽

10.3390/antiox10060894 ◽

2021 ◽

Vol 10 (6) ◽

pp. 894

Author(s):

Cecilia Martínez ◽

Juan Luis Valenzuela ◽

Manuel Jamilena

Keyword(s):

Abiotic Stresses ◽

Nutritional Value ◽

Antioxidant Properties ◽

Plant Diseases ◽

Human Diet ◽

Antioxidant Power ◽

Factors Influencing ◽

Cultivated Species ◽

Plant Families ◽

Valuable Compounds

Cucurbitaceae is one of the most economically important plant families, and includes some worldwide cultivated species like cucumber, melons, and squashes, and some regionally cultivated and feral species that contribute to the human diet. For centuries, cucurbits have been appreciated because of their nutritional value and, in traditional medicine, because of their ability to alleviate certain ailments. Several studies have demonstrated the remarkable contents of valuable compounds in cucurbits, including antioxidants such as polyphenols, flavonoids, and carotenoids, but also tannins and terpenoids, which are abundant. This antioxidant power is beneficial for human health, but also in facing plant diseases and abiotic stresses. This review brings together data on the antioxidant properties of cucurbit species, addressing the genetic and pre- and postharvest factors that regulate the antioxidant content in different plant organs. Environmental conditions, management, storage, and pre- and postharvest treatments influencing the biosynthesis and activity of antioxidants, together with the biodiversity of this family, are determinant in improving the antioxidant potential of this group of species. Plant breeding, as well as the development of innovative biotechnological approaches, is also leading to new possibilities for exploiting cucurbits as functional products.

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Waste-Derived NPK Nanofertilizer Enhances Growth and Productivity of Capsicum annuum L.

Plants ◽

10.3390/plants10061144 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1144

Author(s):

Heba M. M. Abdel-Aziz ◽

Magda I. Soliman ◽

Aml M. Abo Al-Saoud ◽

Ghada A. El-Sherbeny

Keyword(s):

Animal Health ◽

Growth Yield ◽

Chemical Fertilizer ◽

Bovine Bone ◽

Effective Management ◽

Waste Generation ◽

Nano Composite ◽

Global Issue ◽

Npk Fertilizer ◽

Valuable Compounds

Waste generation is a global issue that necessitates effective management for both human and animal health as well as environment. There are several ways to reduce waste, but recycling appears to be the best choice. By recycling, not only will the problem of pollution be resolved, but valuable compounds could be generated to be used as nutrients for plants. In this study, eco-friendly methods were established to produce α- and β-chitosan (CS) (as a source of nitrogen) with different degrees of deacetylation from shrimp shells and squid pin waste, phosphorous through degreasing and calcination of bovine bone and potassium from evaporation of banana peels Kolakhar. The waste bulk products were physically characterized and dry-milled into nano-powders. Different concentrations of the produced nano-NPK fertilizer (10%, 25%, 50% and 100%) were foliar-applied to Capsicum annum L. cv. Cordoba plants and compared to commercial chemical fertilizer and untreated control plants. The obtained results revealed that the nano-composite NPK with 25% concentration significantly promoted growth, yield and harvest of C. annuum as compared with the control and chemical fertilizer-treated plants. This study demonstrated that the use of an eco-friendly preparation of waste NPK composites, with a low concentration, could be applied as foliar fertilizer over chemical fertilizer to enhance the growth and productivity of Capsicum.

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