Biotransformation of ethylene glycol to glycolic acid by Yarrowia lipolytica: A route for poly(ethylene terephthalate) (PET) upcycling.

Biological recycling of PET waste has been extensively investigated recently to tackle plastic waste pollution, and ethylene glycol (EG) is one of the main building blocks recovered from this process. Wild-type Yarrowia lipolytica IMUFRJ 50682 can be a biocatalyst to biodepolymerize PET. Herein, we report its ability to perform oxidative biotransformation of EG into glycolic acid (GA): a higher value-added chemical with varied industrial applications. We found that this yeast tolerates high EG concentrations (up to 2 M) based on maximum non-inhibitory concentration (MNIC) tests. Whole-cell biotransformation assays using resting yeast cells showed GA production uncoupled to cell growth metabolism, and 13 C nuclear magnetic resonance (NMR) analysis confirmed GA production. Moreover, higher agitation speed (450 vs. 350 rpm) resulted in a 1.12-fold GA production improvement (from 352 to 429.5 mM) during Y. lipolytica cultivation in bioreactors after 72 h. GA was constantly accumulated in the medium, suggesting that this yeast may also share an incomplete oxidation pathway (i.e., it is not metabolized to carbon dioxide) as seen in acetic acid bacterial group. Additional assays using higher chain-length diols (1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol) revealed that C4 and C6 diols were more cytotoxic, suggesting that they underwent different pathways in the cells. We found that this yeast consumed extensively all these diols, however, 13 C NMR analysis from supernatant identified solely the presence of 4-hydroxybutanoic acid from 1,4-butanediol, along with GA from EG oxidation. Findings reported herein reveal a potential route for PET upcycling to a higher value-added product.

A critical view on the technology readiness level (TRL) of microbial plastics biodegradation.

Accumulation of plastic wastes and their effects on the ecosystem have triggered an alarm regarding environmental damage, which explains the massive investigations over the past few years, aiming technological alternatives for their proper destination and valorization. In this context, biological degradation emerges as a green route for plastic processing and recycling in a circular economy approach. Some of the main polymers produced worldwide are poly(ethylene terephthalate) (PET), polyethylene (PE) and polypropylene (PP), which are among the most recalcitrant materials in the environment. In comparison to other polymers, PET biodegradation has advanced dramatically in recent years concerning microbial and enzymatic mechanisms, being positioned in a higher technology readiness level (TRL). Even more challenging, polyolefins (PE and PP) biodegradation is hindered by their high recalcitrance, which is mainly related to stable carbon-carbon bonds. Potential microbial biocatalysts for this process have been evaluated, but the related mechanisms are still not fully elucidated. This review aims to discuss the latest developments on key microbial biocatalysts for degradation of these polymers, addressing biodegradation monitoring, intellectual property, and TRL analysis of the bioprocessing strategies using biodegradation performance, process time and scale as parameters for the evaluation.

Phytochemical and pharmacological notes of plants indicated to treat tumors in Brazil

The plants used in traditional medicine have been considered an important source of molecules with pharmacological activity, including antitumor. The aim of this study was to present a pharmacological description and the phytochemical components related to antitumor activity of thirty plants commonly cited in Brazil to treat tumors as well as offering an overview of approaches that are necessary for the development of herbal medicines from these resources. In the search for studies with these plants, five database were used (SciELO, Scirus, Scopus, Biological Abstracts and Web of Science), with the following keywords: tumor AND Species AND cancer. We consider all the scientific synonyms of species available in the Tropicos® database (http://www.tropicos.org/). We surveyed papers from the period between 1980 and 2008. Twnety one species (70 percent) have at least one evaluation of a class of molecule or metabolite isolated against a pharmacological model. Most species (60 percent) has in vivo studies. Of the thirty plant species, two stood out for having pharmacological studies in vitro, in vivo and clinical with positive results: Chelidonium majus L., Papaveraceae, and Aloe arborescens Mill., Xanthorrhoeaceae. Although there is generally a good activity of species presented here, there is a need for further studies in order to evaluate the possibility of developing some byproduct.

Medicinal plants used as antitumor agents in Brazil: an ethnobotanical approach.

WE DESCRIBE THE MEDICINAL PLANTS THAT HAVE BEEN REPORTED TO BE ANTITUMOR AGENTS AND THAT HAVE BEEN USED IN ETHNOBOTANIC RESEARCH IN BRAZIL TO ANSWER THE FOLLOWING QUESTIONS: what is the abundance of plants reported to be antitumor in Brazil? Have the plant species used for tumor treatment in traditional Brazilian medicine been sufficiently examined scientifically? Our analysis included papers published between 1980 and 2008. A total of 84 medicinal plant species were reported to be used for cancer and tumor prevention or treatment; 69.05% of these were cited as being used for the treatment of tumors and cancer in general and 30.95% for specific tumors or cancers. The plants that were cited at a higher frequency were Aloe vera, Euphorbia tirucalli, and Tabebuia impetiginosa. At least, one pharmacological study was found for 35.71% of the species. Majority of the studies selected were conducted in rural communities and urban areas and in areas with traditional healers in Brazil. We found the following molecules to be the most studied in vitro and in vivo: silibinin, ß-lapachone, plumbagin and capsaicin. The species addressed here constitute interesting objects for future studies to various professionals in the field of natural products.