An eco-compatible process for the depuration of wastewater from olive mill industry

Olive mill wastewater (OMW) is the by-product of olive oil industrial production. It is characterized by a dark brownish color and a strong odor and is considered one of the most polluted agricultural wastes. In this paper we briefly describe an innovative procedure for the depuration of olive mill wastewater. With this procedure it is also possible to recover valuable substances such as phenolic compounds which have important commercial applications: they can be used in the prevention of cardiovascular disease and as antiviral, antioxidant and antitumor agents. The proposed OMW treatment uses two different packed vegetable matrices which remove most of the pollutant substances by absorption. After filtration of OMW on the matrices the pollutant load of the waste is greatly reduced: the organic content (COD) is reduced more than 80% and the phenol compounds are completely removed

CHAPTER 11: Environmental Factors Affecting Hydrogen Production from Chlamydomonas reinhardtii

Utilization of renewable sources for energy is becoming an increasing necessity, due to the impending depletion of fossil fuels and consequently the search for alternative sources. Special emphasis on sustainability and environmental compatibility is the catalyst motivating today's bioenergy science. In this respect, hydrogen is a potential candidate for development, considering its advantages as an energy carrier and that its production can be accomplished, using chemical and/or biological processes. Keeping the environment in mind as the keystone for future energy routes, biological hydrogen production is a vital topic for research. Compared to the other microorganisms, the ability of some strains of microalgae to produce hydrogen under defined culture conditions is getting more attention, due to the clean and sustainable nature of their biological processes. Among microalgae that one should highlight is Chlamydomonas reinhardtii, which is well studied both under laboratory and outdoor conditions. Reaching the ultimate goal of a commercial system will require understanding the overall biological process, from the single cell to the complex environmental interaction level. Within this context, this chapter discusses step-by-step the hydrogen-production process by microalgae with a specific focus on C. reinhardtii, considering key environmental factors such as light, temperature, pH, and fluid dynamics. © European Society for Photobiology 2018

Genetic Optimization of Microalgae for Biohydrogen Production

Hydrogen is a promising energy carrier that has an important share in the global energy market when produced in conventional ways. Today, most hydrogen production depends on thermochemical processes of fossil sources. The promising search for renewable and sustainable energy to compete with or support fossil fuels has opened a new era for hydrogen production from biological sources. Hydrogen, as an emission-free gas with high gravimetric energy gas, has encouraged studies to investigate new production strategies from living microorganisms. This chapter discusses the scope of the genetic optimization of microalgae for biohydrogen production, using Chlamydomonas reinhardtii as a model organism. © 2015 Elsevier Inc. All rights reserved

Interplay between photochemical activities and pigment composition in an outdoor culture of Haematococcus pluvialis during the shift from the green to red stage

9th International Conference on Applied Algology -- MAY 26-30, 2002 -- AGUADULCE, SPAINWOS: 000183045600007The transfer of laboratory cultures of H. pluvialis to high irradiance outdoors caused a substantial decline in the maximum quantum yield of photosystem II (PSII), from 0.65 in the morning to 0.45 at midday, as measured by the ratio of variable to maximum fluorescence yields (F(v)/F(m)), and a steep rise in non-photochemical quenching (NPQ). Chlorophyll fluorescence induction curves of morning samples showed a clear I-step, reflecting a certain PSII heterogeneity. Single turnover flash measurements on samples taken from the outdoor photobioreactor in the middle of day showed an increase in the reoxidation time constant of the reduced plastoquinone Q(A)(-), i.e., the time required for electron transfer from the primary plastoquinone acceptor of PSII Q(A)(-) to the secondary plastoquinone acceptor Q(B). Photosynthesis rates were almost constant during the day. Along with the increase in non-photochemical quenching, there was a slight increase in zeaxanthin and antheraxanthin contents and decrease in violaxanthin, showing the presence of an operative xanthophyll cycle in this microalga. A marked increase of secondary carotenoids was found at the end of the first day of exposure to sunlight, mainly astaxanthin monoester, which reached 15.5% of the total carotenoid content. Though cells turned reddish during the second day, the decline in the fluorescence parameter F(v)/F(m) in the middle of the day was less than during the first day, and there was no further increase in the value for NPQ. Similar behaviour was observed during the third day when the culture was fully red. After four days of exposure to sunlight, the dry weight reached 800 mg L(-1) and the concentration of secondary carotenoids (81% astaxanthin monoester) reached 4.4% dry weight.Int Soc Appl Phyco

Characterization of phenolic profile and antioxidant activity of the leaves of the forgotten medicinal plant Balsamita major grown in Tuscany, Italy, during the growth cycle

Balsamita major (Asteraceae), known as costmary, is a medicinal plant rich of ethnobotanical interest in particular in Europe and Middle East, known and used since Greek and Roman times. The aim of the present study was to characterize the phenolic pattern of B. major leaves cultivated in Italy, and to measure the overall anti-radical (DPPH) and antioxidant activity (ORAC) during the growth cycle of the plant. Total polyphenols and total hydroxycinnamic acid derivatives were abundant in the leaves collected at all the growth stages, only decreasing in the flowering stage; flavonoids reached the highest content in the very early growth stage. Chlorogenic acid and 3,5-O-dicaffeoylquinic acid resulted to be the main phenolic constituents in all the extracts; their concentrations were highest at the late and early growth stages, respectively. Glycosilated flavonoids were found to be the abundant in all the extracts and quercetin resulted the main flavonoid aglycone, with the highest content in the very early growth stage. Both DPPH and ORAC tests registered good antiradical and antioxidant properties for all the extracts. Thus, B. major is worthy of further investigation, being an interesting source of antioxidant compounds, for pharmaceutical, nutraceutical and cosmetic purposes

Unusual Catalysts from Molasses: Synthesis, Properties and Application in Obtaining Biofuels from Algae

Acid catalysts were prepared by sulfonation of carbon materials obtained from the pyrolysis of sugar beet molasses, a cheap, viscous byproduct in the processing of sugar beets into sugar. Conditions for the pyrolysis of molasses (temperature and time) influenced catalyst performance; the best combination came from pyrolysis at low temperature (420\ub0C) for a relatively long time (8-15a H), which ensured better stability of the final material. The most effective molasses catalyst was highly active in the esterification of fatty acids with methanol (100% yield after 3a H) and more active than common solid acidic catalysts in the transesterification of vegetable oils with 25-75 wt% of acid content (55-96% yield after 8a H). A tandem process using a solid acid molasses catalyst and potassium hydroxide in methanol was developed to de-acidificate and transesterificate algal oils from Chlamydomonas reinhardtii, Nannochloropsis gaditana, and Phaeodactylum tricornutum, which contain high amounts of free fatty acids. The amount of catalyst required for the de-acidification step was influenced by the chemical composition of the algal oil, thus operational conditions were determined not only in relation to free fatty acids content in the oil, but according to the composition of the lipid extract of each algal species

Biohydrogen production from model microalgae Chlamydomonas reinhardtii: A simulation of environmental conditions for outdoor experiments

WOS: 000356549000011Microalgae have remarkable molecular pathways to generate biohydrogen, an environment friendly and sustainable energy source. For this reason, various studies for microalgal biohydrogen production have been carried out. The objective of the present study was to address the effect of environmental factors simulating outdoor conditions using D1 mutant strains and CC124 as control strain. The results showed that, in any cases D1 mutants were effective in terms of hydrogen generation capacity; however among them strain D239-40 has attractive in term of hydrogen output. The results are promising for further developments both in genetic and bioprocess aspect aiming scale up and commercialization for outdoor cultures. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.National Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111M609]; Istituto per lo Studio degli Ecosistemi (CNR) [111M609]The authors would like to thank for National Research Council of Turkey (TUBITAK) and Istituto per lo Studio degli Ecosistemi (CNR) for their financial support (Bilateral Project No: 111M609)

Biohydrogen production using mutant strains of Chlamydomonas reinhardtii: The effects of light intensity and illumination patterns

WOS: 000344825400009Biohydrogen production from microalgae still remains to be discussed and examined more specifically, given that it is one of the most important energy carriers possessing environmental-friendly and sustainable characteristics. Although microalgae species capable of biohydrogen production do exist, Chlamydomonas reinhardtii is considered to be one of the most promising eukaryotic H-2 producers, and can serve as a model organism for such studies. Unfortunately, even if the metabolic basis and environmental conditions for this process are well defined, the sustainability of biohydrogen production is not straightforward. At this point, genetic engineering tools must be efficacious in order to enable mutant strains to reach desired amounts of biohydrogen. In this study, different light intensities, illumination patterns and Chlamydomonas strains such as CC124 and D1 protein mutant strains (D240, D239-40, D240-41) were investigated for the production of biohydrogen. The results showed that an increase in the light intensity shortened the lag phase of hydrogen production. With some minor differences, biohydrogen production was also found to be affected by the illumination pattern. On the other hand, maximum biohydrogen production was reached with a double-deletion mutant strain of D239-40, which attained a total production of 490 +/- 10 mL L-1 hydrogen and was followed by the other double-deletion mutant D240-41 that attained a total production of 388 +/- 10 mL L-1. (C) 2014 Elsevier B.V. All rights reserved.Scientific and Technological Resarch Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); National Research Council of Italy (CNR)Italian National Research Council [111M609]The authors would like to thank the Scientific and Technological Resarch Council of Turkey (TUBITAK) and the National Research Council of Italy (CNR) (111M609) for their financial support

Antioxidant Defences and Oxidative Damage in Salt-treated Olive Plants under Contrasting Sunlight Irradiance

The interactive effects of root-zone salinity and sunlight on leaf biochemistry, with special emphasis on antioxidant defences, were analysed in Olea europaea L. cv. Allora, during the summer period. Plants were grown outside under 15% (shade plants) or 100% sunlight (sun plants) and supplied with 0 or 125 mM NaCl. The following measurements were performed: (1) the contribution of ions and soluble carbohydrates to osmotic potentials; (2) the photosystem II (PSII) photochemistry and the photosynthetic pigment concentration; (3) the concentration and the tissue-specific distribution of leaf flavonoids; (4) the activity of antioxidant enzymes; and (5) the leaf oxidative damage. The concentrations of Na+ and Cl- were significantly greater in sun than in shade leaves, as also observed for the concentration of the ‘antioxidant’ sugar–alcohol mannitol. The de-epoxidation state of violaxanthin-cycle pigments increased in response to salinity stress in sun leaves. This finding agrees with a greater maximal PSII photochemistry (Fv/Fm) at midday, detected in salt-treated than in control plants, growing in full sunshine. By contrast, salt-treated plants in the shade suffered from midday depression in Fv/Fm to a greater degree than that observed in control plants. The high concentration of violaxanthin-cycle pigments in sun leaves suggests that zeaxanthin may protect the chloroplast from photo-oxidative damage, rather than dissipating excess excitation energy via non-photochemical quenching mechanisms. epidermal cells, in response to high sunlight. The activity of antioxidant enzymes varied little because of sunlight irradiance, but declined sharply in response to high salinity in shade leaves. Interestingly, control and particularly salt-treated plants in the shade underwent greater oxidative damage than their sunny counterparts. These findings, which conform to the evolution of O. europaea in sunny environments, suggest that under partial shading, the antioxidant defence system may be ineffective to counter salt-induced oxidative damage Dihydroxy B-ring-substituted flavonoid glycosides accumulate greatly in the mesophyll, not only in the epidermal cells, in response to high sunlight. The activity of antioxidant enzymes varied little because of sunlight irradiance, but declined sharply in response to high salinity in shade leaves. Interestingly, control and particularly salt-treated plants in the shade underwent greater oxidative damage than their sunny counterparts. These findings, which conform to the evolution of O. europaea in sunny environments, suggest that under partial shading, the antioxidant defence system may be ineffective to counter salt-induced oxidative damage