Phytoremediation for heavy metal‐contaminated soils combined with bioenergy production

In June 2007, a project started in Flanders (Belgium) in which we will apply phytoremediation to clean soils that are diffusely polluted with heavy metals. Uptake ranges of heavy metals by rape seed, maize and wheat will be enhanced by increasing the bioavailability of these heavy metals by the addition of biodegradable physico‐chemical agents and by stimulating the heavy‐metal uptake capacity of the microbial community in and around the plant. In addition, the harvested biomass crops will be converted into bioenergy by using different energy‐recovery‐techniques. The energy and heavy metal mass balances will be compared for four different energy‐recovery techniques (anaerobic digestion, incineration, gasification and production of biodiesel). The overall information obtained will result in an economic evaluation of the use of phytoremediation combined with bioenergy production for the remediation of sites which are diffusely polluted with heavy metals. In the present review we will first explain the most important research steps investigated in our phytoremediation project. Secondly, an overview of literature discussing the phytoremediation capacity of rape seed to clean soils that are contaminated with heavy metals and the possibilities to produce biodiesel from this (heavy metal polluted) rape seed will be discussed in more detail. Fitoremediacijos taikymas sunkiaisiais metalais užterštame dirvožemyje derinant su bioenergijos gamyba Santrauka. 2007 m. birželį Flandrijoje (Belgija) pradėtas vykdyti projektas, kuriame mes pritaikysime fitoremediaciją siekdami išvalyti sunkiuosius metalus iš dirvožemio. Sunkiųjų metalų patekimas į rapsus, kukurūzus ir kviečius bus suintensyvintas didinant šių sunkiųjų metalų biopriimamumą dėl pridedamų biodegraduojančių fizikinių-cheminių priedų bei stimuliuojant mikrobiologinių bendrijų pajėgumą augale ir aplink jį sugerti sunkiuosius metalus. Be to, nuimta javų biomasė bus perdirbta į bioenergiją, taikant įvairias energijos gavybos technologijas. Energijos ir sunkiųjų metalų masės balansas bus palygintas pagal keturias skirtingas energijos gavybos technologijas (anaerobinis kompostavimas, deginimas, dujofikavimas ir biodyzelio gamyba). Visa gauta informacija leis ekonominiu požiūriu įvertinti fitoremediacijos, derinamos su bioenergijos gamyba, taikymą valant sunkiaisiais metalais nevienodai užterštus plotus. Pateikiamoje apžvalgoje pirma aptarsime svarbiausius fitoremediacijos projekto etapus. Antra, detaliau apžvelgsime literatūrą apie rapsų pajėgumą išvalyti dirvožemį, užterštą sunkiaisiais metalais, ir galimybes gaminti biodyzelį iš (sunkiaisiais metalais užterštų) rapsų sėklų. Reikšminiai žodžiai: fitoremediacija, sunkieji metalai, biomasė, energijos gamyba, rapsai, biodyzelis. Применение фиторемедиации в почве, загрязненной тяжелыми металлами и приспосабливаемой для производства биоэнергии Резюме. В июне 2007 г. во Фландере (Бельгия) была начата работа над проектом по фиторемедиации с целью очищения почвы от тяжелых металлов. Процесс поглощения тяжелых металлов рапсом, кукурузой и пшеницей будет более интенсивным благодаря введению биодеградирующих физико-химических добавок и стимуляции способности микробиологических сообществ в растении и вокруг него впитывать тяжелые металлы. Снятая биомасса зерновых с помощью различных технологий по производству энергии будет конвертирована в биоэнергию. Баланс энергии и массы тяжелых металлов будет сравнен с помощью четырех разных технологий по производству энергии (анаэробического компостирования, сжигания, газофикации, производства биотоплива). Полученная информация позволит с экономической точки зрения оценить применение фиторемедиации как для очищения площадей, в разной степени загрязненных тяжелыми металлами, так и для производства биоэнергии. В статье прежде всего проанализированы важнейшие этапы проекта по фиторемедиации. Затем произведен обзор литературы о способности рапса благодаря фиторемедиации очищать почву, загрязненную тяжелыми металлами, и возможностях производства биотоплива из семян рапса, загрязненных тяжелыми металлами. Ключевые слова: фиторемедиация, тяжелые металлы, биомасса, производство энергии, семена рапса, биотопливо. First Published Online: 14 Oct 201

Pectin content and composition from different food waste streams

n/

Interlaboratory exercise for the analysis of carotenoids and related compounds in dried mango fruit (Mangifera indica L.)

An interlaboratory comparison was done for the analysis of carotenoids in freeze-dried mango. The study was performed from July to September 2018. Mango fruit was freeze-dried, homogenized, and packaged under vacuum conditions in portions of 6 g (test sample). Two test samples were sent to the participating laboratories for analysis. Laboratory results were rated using Z-scores in accordance with ISO 13528 and ISO 17043. The standard deviation for proficiency assessment (also called target standard deviation) was determined using a modified Horwitz function and varied between 10% and 25%, depending on the analyte. Out of 14 laboratories from 10 different countries, 9 laboratories (64%) obtained a satisfactory performance (Z ≤ 2) for the analysis of β-carotene. While for 7 laboratories that analyzed α-carotene, (9Z)-β-carotene, β-cryptoxanthin, and zeaxanthin, 4 laboratories (57%) obtained a satisfactory performance. However, only 2 laboratories out of 7 (29%) obtained a satisfactory performance for lutein. Based on the comparability of the analytical results, this study concludes that freeze-dried mango pulp can be used as a reference material for the analysis of α and β-carotene, (9Z)-β-carotene, β-cryptoxanthin, and zeaxanthin by applying different analytical procedures for their extraction and quantification.This work was performed within the frame of the TEAM EC2017TEA442A103 VLIR-UOS project “Improving Ecuadorian child nutrition by using mango by-products as potential sources of bioactive compounds”. JV-Ch wants to acknowledge the quality technical support of Samara Fernández de Souza from VITO. VM-P acknowledges Mayra Anaguano from EPN. AZM acknowledges Fabiane C. Petry for the carotenoid analysis, FAPESP (grant 2018/23752-1) and CNPq (grant 309182/2018-2).Peer reviewe

Supercritical CO2 Extraction of Nannochloropsis sp.: A Lipidomic Study on the Influence of Pretreatment on Yield and Composition

Algal lipids have gained wide interest in various applications ranging from biofuels to nutraceuticals. Given their complex nature composed of different lipid classes, a deep knowledge between extraction conditions and lipid characteristics is essential. In this paper, we investigated the influence of different pretreatments on lipid extraction with supercritical CO2 by a lipidomic approach. Pretreatment was found to double the total extraction yield, thereby reaching 23.1 wt.% comparable to the 26.9 wt.% obtained with chloroform/methanol. An increase in acylglycerides was concurrently observed, together with a nearly doubling of free fatty acids indicative of partial hydrolysis. Moreover, an alteration in the distribution of glyco- and phospholipids was noted, especially promoting digalactosyldiglycerides and phosphatidylcholine as compared to monogalactosyldiglycerides and phosphatidylglycerol. At optimized conditions, supercritical CO2 extraction provided a lipid extract richer in neutral lipids and poorer in phospholipids as compared to chloroform/methanol, though with a very similar fatty acid distribution within each lipid class

Pectic oligosaccharides from agricultural by-products: production, characterization and health benefits

Pectin containing agricultural by-products are potential sources of a new class of prebiotics known as pectic oligosaccharides (POS). In general, pectin is made up of homogalacturonan (HG, α-1,4-linked galacturonic acid monomers) and rhamnogalacturonan (RG, alternate galacturonic acid and rhamnose backbone with neutral side chains). Controlled hydrolysis of pectin containing agricultural by-products like sugar beet, apple, olive and citrus by chemical, enzymatic and hydrothermal can be used to produce oligo-galacturonides (GalpOS), galacto-oligosaccharides (GalOS), rhamnogalacturonan-oligosaccharides (RGOS), etc. However, extensive research is needed to establish the role of POS, both as a prebiotic as well as therapeutic agent. This review comprehensively covers different facets of POS, including the nature and chemistry of pectin and POS, potential agricultural residual sources of pectin, pre-treatment methods for facilitating selective extraction of pectin, identification and characterization of POS, health benefits and important applications of POS in food and feed. This review has been compiled to establish a platform for future research in the purification and characterization of POS and for in vivo and in vitro studies of important POS, so that they could be commercially exploited

Flow cytometry to estimate the cell disruption yield and biomass release of Chlorella sp. during bead milling

A number of visual, chemical and fluorescence-based methods are generally employed for monitoring of algae cell growth, culture health and biomass concentration. These methods are often time-consuming, demand destructive and high volume sampling. Rapid, efficient, cost-effective and automated methods which facilitate high-throughput and non-destructive sampling would highly benefit microalgae biotechnology. It is known in literature that with flow cytometry it is possible to monitor microalgae growth and microalgae culture health. Flow cytometry, however, has not been used to estimate biomass release and cell disruption yield. In this study with representative cultures of Chlorella sp., flow cytometry data were generated by a long pass filter (> 670 nm) and proved to be a promising technique to rapidly evaluate these parameters during cell disruption by bead milling. Both a laboratory and a commercial culture of Chlorella were bead milled. Prior to and during bead milling, biomass release was evaluated gravimetrically and the cell count was determined via hemocytometer manual counting and 3 flow cytometry methods: 1) direct event count of a certain population, 2) quadrant-upper right event count of a long pass filter (> 670 nm) and 3) a calculation based on the long pass filter data. The data of all methods were compared and correlated to gravimetric biomass release data. Manual counting resulted in an underestimation of the cell disruption yield as one of the Chlorella cultures manual counts did not agree with biomass release data. Good correlations for both cultures were found for cell disruption yield calculations based on flow cytometry data and gravimetric biomass release data. Flow cytometry is therefore an efficient analytical method to rapidly screen disruption yields during cell disruption in microalgae and can be a substitute for the time-consuming direct methods (e.g. gravimetric, manual counting) for estimating biomass release and cell disruption yield

Influence of nitrogen depletion in the growth of N. oleoabundans on the release of cellular components after beadmilling

Cell disruption by bead milling of Neochloris oleoabundans grown under nitrogen repleted (NR) and nitrogen depleted (ND) conditions was evaluated based on the release of biochemicals and biomass to the supernatant. Additionally, energy consumption for cell disruption was calculated per kg of released component. Bead milling of NR cells resulted on average in 34% (w/w) release of biochemicals into the supernatant, with a similar composition as the untreated microalgal biomass. With ND cells, the release was higher and more selective, i.e. 57%, 59%, 68% and 56% (w/w) of respectively biomass, proteins, carbohydrates and lipids whereof 92%, 57% and 46% (w/w) respectively of phospho-, glyco- and neutral lipids.</p