Selective fractionation of free glucose and starch from microalgae using aqueous two-phase systems

Microalgae are a promising source of lipids, pigments, proteins and carbohydrates, which are valuable compounds for many industries. However, optimal fractionation and valorization of all produced compounds is necessary to improve the economic viability of microalgae production. This paper aims to understand the fractionation of microalgae carbohydrates (free glucose and starch) in aqueous two-phase systems. Three aqueous two-phase systems were investigated to efficiently and mildly separate carbohydrates from disrupted Neochloris oleoabundans. This strain contains 16 w/w% of proteins, 48 w/w% total fatty acids and 27 w/w% carbohydrates when cultivated under saline water and nitrogen depletion conditions. The protein content decreases and the amount of fatty acids and carbohydrates increases notably under stress conditions and glucose becomes the main carbohydrate in this microalgae. Glucose is present in the disrupted microalgae as part of polymeric carbohydrates (starch) or in monomeric form (free glucose). With the aqueous two-phase system Polyethylene Glycol 400 - Cholinium dihydrogen phosphate (PEG400-ChDHp) microalgal free glucose is fractionated up to a recovery of 99% to the most hydrated bottom phase in a single step. Simultaneously, a recovery of 70% is reached for microalgal starch in the interface after two additional liquid-liquid extractions with PEG400-ChDHp. The final fractions obtained were free of pigments.publishedVersionPaid Open Acces

Comparison of bio-oils derived from crop digestate treated through conventional and microwave pyrolysis as an alternative route for further waste valorization

A total of 120,000 tonnes per year of crop waste from contaminated land has been used as a feedstock for anaerobic digestion (AD). This produces only around 20% of biogas from the total crop and results in a large amount of digestate with heavy metal content. This crop digestate was analyzed across a calendar year to identify the variation in composition, and any potential high-value components that could be targeted for recovery. The chemical characterization revealed that approximately 65% of this residual waste is lignocellulosic material (20% hemicellulose, 24% cellulose, 24% lignin) and about 10% is ash, with no observable difference across the seasons. Three different pyrolysis technologies were studied with the same crop digestate as alternative route to maximize the value of this solid residue by transforming this lignocellulosic material into further bio-based products. Slow pyrolysis at operating temperatures between 355 and 530 °C resulted in bio-oil yields of 35–46% wt, fast pyrolysis at 460–560 °C produced 36–40% wt, and microwave pyrolysis using a power input of 500 and 700 W generated 8–27% wt from the digestate. Chemical compounds found in these bio-oils were categorized into seven chemical groups: acids, aldehydes and ketones, alcohols, furans, sugars, phenolics, and others. This analytical study opens other scenarios to explore the upgrading of these pyrolytic bio-oils for green product generation from the same waste

Correction to: Comparison of bio-oils derived from crop digestate treated through conventional and microwave pyrolysis as an alternative route for further waste valorization

In this article the Table 3 with SD± was not properly adjusted. The original article has been corrected

MAB2.0 project: Integrating algae production into wastewater treatment

Different species of microalgae are highly efficient in removing nutrients from wastewater streams and are able to grow using flue gas as a CO2 source. These features indicate that application of microalgae has a promising outlook in wastewater treatment. However, practical aspects and process of integration of algae cultivation into an existing wastewater treatment line have not been investigated. The Climate-KIC co-funded Microalgae Biorefinery 2.0 project developed and demonstrated this integration process through a case study. The purpose of this paper is to introduce this process by phases and protocols, as well as report on the challenges and bottlenecks identified in the case study. These standardized technical protocols detailed in the paper help to assess different aspects of integration including biological aspects such as strain selection, as well as economic and environmental impacts. This process is necessary to guide wastewater treatment plants through the integration of algae cultivation, as unfavourable parameters of the different wastewater related feedstock streams need specific attention and management. In order to obtain compelling designs, more emphasis needs to be put on the engineering aspects of integration. Well-designed integration can lead to operational cost saving and proper feedstock treatment enabling algae growth

Chitin and Chitosan : Properties and Applications

Offers a comprehensive guide to the isolation, properties and applications of chitin and chitosan Chitin and Chitosan: Properties and Applications presents a comprehensive review of the isolation, properties and applications of chitin and chitosan. These promising biomaterials have the potential to be broadly applied and there is a growing market for these biopolymers in areas such as medical and pharmaceutical, packaging, agricultural, textile, cosmetics, nanoparticles and more.The authors – noted experts in the field – explore the isolation, characterization and the physical and chemical properties of chitin and chitosan. They also examine their properties such as hydrogels, immunomodulation and biotechnology, antimicrobial activity and chemical enzymatic modifications. The book offers an analysis of the myriad medical and pharmaceutical applications as well as a review of applications in other areas. In addition, the authors discuss regulations, markets and perspectives for the use of chitin and chitosan. This important book: Offers a thorough review of the isolation, properties and applications of chitin and chitosan. Contains information on the wide-ranging applications and growing market demand for chitin and chitosan Includes a discussion of current regulations and the outlook for the futureWritten for Researchers in academia and industry who are working in the fields of chitin and chitosan, Chitin and Chitosan: Properties and Applications offers a review of these promising biomaterials that have great potential due to their material properties and biological functionalities

Potential Protein Production from Lignocellulosic Materials Using Edible Mushroom Forming Fungi

There is a need for new protein sources to feed the world in a sustainable way. Converting non-food-grade “woody” side streams into food containing proteins will contribute to this mission. Mushroom forming fungi are unique in their capability to convert lignocellulosic substances into edible biomass containing protein. Especially if substrate mycelium can be used instead of mushrooms, this technology could be a serious contribution to addressing the protein challenge. In this Perspective, we discuss challenges toward production, purification, and market introduction of mushroom mycelium based foods

The effect of me-substituents of 1,4-butanediol analogues on the thermal properties of biobased polyesters

Biobased 1,4‐butanediol analogues are used to tune the glass transition temperature and crystallization in a series of polyesters, and allow for the formation of stereocomplexes

Nitrogen-to-Protein Conversion Factors for Three Edible Insects : Tenebrio molitor, Alphitobius diaperinus, and Hermetia illucens

Insects are considered a nutritionally valuable source of alternative proteins, and their efficient protein extraction is a prerequisite for large-scale use. The protein content is usually calculated from total nitrogen using the nitrogen-to-protein conversion factor (Kp) of 6.25. This factor overestimates the protein content, due to the presence of nonprotein nitrogen in insects. In this paper, a specific Kp of 4.76 ± 0.09 was calculated for larvae from Tenebrio molitor, Alphitobius diaperinus, and Hermetia illucens, using amino acid analysis. After protein extraction and purification, a Kp factor of 5.60 ± 0.39 was found for the larvae of three insect species studied. We propose to adopt these Kp values for determining protein content of insects to avoid overestimation of the protein content.</p

Correction to : Comparison of bio-oils derived from crop digestate treated through conventional and microwave pyrolysis as an alternative route for further waste valorization

In this article the Table 3 with SD± was not properly adjusted. The original article has been corrected