Search

Sustainable waste management for orange peel waste is a global concern that presents a concomitant opportunity. In this study, a combined process was developed to optimize the simultaneous recovery of pectin, essential oils, and sugars from industrial orange peel waste. The sequential recovery process was used as a benchmark, while a one-pot combined process was optimized through the design of the experiments. A multi-objective desirability function was computed to maximize process performance while balancing opposing optimal conditions. The aim was to find a model able to confidently predict yields while reducing the process environmental footprint, potentially giving the necessary multi-product flexibility in modern biorefining. As a result, the combined process under optimal conditions, liquid-to-solid ratio of 2.5, pH value of 3.7, and residence time of 130 min, yielded 0.52% of essential oils and 11% of pectin on a dry basis. The environmental factor 18 is relevant to the fine chemicals industry, which is the target sector of this study. Finally, the process mass balance was calculated, demonstrating the opportunity to further enhance process environmental sustainability and efficiency by upgrading the resulting solid fraction. [ABSTRACT FROM AUTHOR]

The screening of plant-derived compounds with anti-cancer properties is a promising strategy to meet the growing need for new, safe and effective anti-cancer drugs. Justicidin B is a plants secondary metabolite that displays anti-cancer properties in several tumor cells. Therefore, it represents a good candidate. We used the 3R-compliant organism Caenorhabditis elegans to evaluate the safety of justicidin B produced by in vitro-grown adventitious roots of Linum lewisii. We showed that a dose of 100 µg/mL justicidin B does not affect worm vitality in either short-term or chronic administration; in contrast, the 200 µg/mL dose induces a lifespan reduction, but only in short-term daily treatment. We attributed this effect to its accumulation in lipofuscin granules in the pharynx as observed through confocal analysis. HPLC analysis confirmed the higher accumulation justicidin B with a 200 µg/mL dose but also revealed the presence of metabolic derivatives that could be responsible for the toxicity. We also demonstrated that the 100 µg/mL dose does not affect worm fertility or development. Our results highlight the safety of justicidin B, supporting its employment in cancer therapy, and encourage the use of a C. elegans model as an appropriate tool to assess compounds' toxicity before moving to more complex organisms. [ABSTRACT FROM AUTHOR]

Hemp hurds are the main byproduct from hemp fibers supply chain and they could represent valuable feedstock of lignocellulosic biomass for biorefineries. The industrial hemp variety "Carmagnola", is characterized by low amounts of ash and high amount of carbohydrates. Alpha-cellulose (44% w/w), hemicellulose (25%), and lignin (23%) were fractionated using an organosolv pretreatment. The enzymatic hydrolysis of the cellulose fraction yielded up to 60% of glucose, that can easily find application as substrate for industrial fermentations. On the other hand, the black liquor originating from hemicellulose contains mainly xylose and minor amounts of other sugars. In the perspective of finding an application of black liquor, 50 yeasts belonging to 24 ascomycetous species were screened both in aerobiosis and anaerobiosis for the production of ethanol and the sugar alcohols xylitol and arabitol from xylose. Pichia fermentans WC 1507, Wickerhamomyces anomalus WC 1501, and Kluyveromyces bacillosporus WC 1404 were found to consume xylose, yielding xylitol in aerobic conditions. In particular, aerobic flask cultures of P. fermentans WC 1507 containing 120 g/L xylose showed the highest xylitol production values, yielding 63.5 g/L xylitol with a YP/S of 71.5%. Black liquor, exploited as a carbon source, has been successfully utilized by the three selected yeast strains at a concentration of 20 g/L in the culture medium, resulting in comparable or higher yields of biomass and xylitol compared to the medium containing pure xylose. A higher concentration of black liquor in the culture medium (to reach 120 g/l of xylose) has determined an inhibition of the growth of yeasts indicating the need for treatments for the removal of inhibitors. These preliminary results can be considered promising for the microbial valorization of lignocellulosic hemp feedstock toward the production of xylitol. [ABSTRACT FROM AUTHOR]

Active-site models of enzymes are important tools that help researchers in understanding and predicting the stereochemical outcome of enzymatic reactions. In this article, various active-site models for dehydrogenases, hydrolases, oxygenases, and oxynitrilases have been reviewed. Key words: Active-site model, cubic space, enzyme model, dehydrogenases, hydrolases, oxygenases, oxynitrilases.