Participation in the European Biotechnology Congress 2021

The European Congress of Biotechnology 2021, despite the complicated epidemiological situation, provided a great opportunity to exchange ideas and create cooperation between successful scientists working in various fields of biotechnology.

The event offered a diverse science program, poster sessions and an attractive social program. The team took part with a poster on the topic: “Antibacterial and antioxidant activity of waste fractions from the essential oil industry” and a presentation presented by Assoc. Prof. Dr. Dimitar Peshev on the topic: “Application of nanomembrane separation for isolation of natural biologically active components”

Abstracts:

Снимка: eurobiotech2021

“Antibacterial and antioxidant activity of waste fractions from the essential oil industry”

Yoana Stoyanova*, N. Georgieva*, N. Lazarova-Zdravkova*, D. Tsanova*, D. Peshev**
*Department of Biotechnology, Faculty of Chemical and System Engineering, UCTM, Sofia, Bulgaria
**Department of Chemical Engineering, UCTM, Sofia, Bulgaria

Tens of millions of tonnes of waste plant mass are generated every year, which in the areas with traditions in the production of essential oils becomes an environmental problem. Due to the presence of volatile organic components and polyphenolic compounds in the waste products, they are expected to exhibit antimicrobial and antioxidant activity and their uncontrolled disposal has an adverse effect on the ecological balance due to pollution of surface and groundwater. Moreover, valuable substances with biological activity are lost.

The aim of the present work is to study the antibacterial and antioxidant activity of waste materials from the production of essential oils. The accurate determination of the wastes biological activity enables their valorisation. Gram-negative Escherichia coli K12 407 and Gram-positive Bacillus subtilis 3562 bacterial strains were used to study the inhibitory ability of the studied samples. The method of micro-dilution in broth was used to test the susceptibility of the bacteria against the waste fractions. Antioxidant activity was determined spectrophotometrically using the DPPH method.

Keywords: antibacterial, antioxidant, waste product, essential oil.

Acknowledgements: This work was supported by the Bulgarian National Science Fund (contract KP-06-H37/14)

e-mail: yoana.d.stoyanova@gmail.com (Y.Stoyanova), neli@uctm.edu (N.Georgieva), d.peshev@uctm.edu (D. Peshev)


“Application of nanomembrane separation for isolation of natural biologically active components.”

Yoana Stoyanova*, N. Lazarova-Zdravkova*, V. Nemska*, N. Georgieva*, D. Peshev**
*Department of Biotechnology, Faculty of Chemical and System Engineering, UCTM, Sofia, Bulgaria
**Department of Chemical Engineering, UCTM, Sofia, Bulgaria

Recent development of new solvent-stable materials has permitted the application of membrane filtration techniques to different processes in organic solvents and solvent mixtures. The biologically active constituents of plants are traditionally isolated trough solid-liquid extraction and further evaporation of the obtained dilute liquid extracts. Due to their susceptibility to thermal degradation and oxidation, traditional thermal separation technologies result in poor product quality. Significant reduction of the specific energy consumption while preserving product activity during the concentration or fractionation of liquid extracts from rosemary or spent coffee grounds, using nanofiltration, is demonstrated via experimental data and process simulations.

Particular attention is drawn on the current results of a project for fundamental research dealing with application of nanofiltration for valorisation of the waste streams from the essential oil industry. The possibility to fractionate hydrosols and extracts (residual waters) from the steam and hydrodistillation of essential oil plants using nanofiltration was investigated. The separation performance of five commercial nanofiltration membranes with respect to key biologically active components of the studied waste aqueous fractions was predicted based on regression models. Membranes of different MWCO, structure and composition were analysed. The model parameters and the distribution of biologically active compounds in the aqueous effluents and waste plant mass were theoretically predicted using the COSMO-RS method, which has the quantum-chemical basis of the Conductor-like Screening Model (COSMO). The results showed that independently on the membrane material, the polymeric membranes exhibit high retention capability against charged solutes such as the contained in the residual waters phenolic acids. Since the pKa of the phenolic compounds, representatives of the flavonoid family is within the range of pH of the aqueous extracts, their retention or permeation could be controlled by slight variations of the pH. The dissolved in the aqueous fractions essential oil components would be easily permeating through the membranes. These results clearly demonstrated the viability of nanofiltration for isolation of refined polyphenolic fractions from the extracts effluents and for recovery of phenethyl alcohol from hydrosols of Rosa damascena.

Acknowledgements: This work was supported by the Bulgarian National Science Fund (contract KP-06-H37/14)

Corresponding author: Dr. DimitarPeshev, Associate Prof., Department of Chemical Engineering, Faculty of Chemical and System Engineering, UCTM, 8 Kliment Ohridski, 1756 Sofia, Bulgaria, tel.: ++359 2 8163287, mobile: ++359 898 266 880; E-mail: d.peshev@uctm.edu

For more information

You can learn more about the event at the following address:

https://uctm.edu/bg/blog/2019-11-13-14-53-57/selebration


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