Speakers

Biography

Nedyalka Valcheva is working on the dissertation on " Physical, chemical, and microbiological characteristics of mineral, mountain, and spring waters from Bulgaria, and biological properties of identified microorganisms” at the Institute of Cryobiology and Food Technologies, Agricultural Academy, town Sofia, Bulgaria, with a DSc. Master’s degree program in "Technology of vegetable, food and flavor products" in University of Food Technologies, town Plovdiv, Bulgaria in 1990.

Abstract

Many mineral, healing, and spring waters in Bulgaria are not subject to physicochemical and microbiological control but are used for the drinking needs of the population. Similar water sources are located in almost all regions in the country. Microorganisms with valuable properties and biologically active substances have been found in many minerals, hyperthermal, thermal, and non-thermal spring waters worldwide and in our country. This opens up a new opportunity for researchers to isolate and identify new microorganisms that may apply to people's lives. The investigation aimed to study the physical, chemical, and microbiological characterization of mineral, mountain, and spring waters from Bulgaria and the biochemical analysis of the microorganisms identified. Physical, chemical, and microbiological characterization of 90 mineral, mountain, and spring waters from 11 regions in the country – Haskovo, Stara Zagora, Yambol, Sliven, Burgas, Varna, Plovdiv, Pazardzhik, Sofia, Lovech, and Blagoevgrad – was carried out. Molecular genetic identification of 91 isolated microorganisms from 90 mineral, mountain, and spring waters from 11 regions of the country was carried out for the first time. They belong to the following eight genera: Bacillus, Brevibacillus, Geobacillus, Aeromonas, Klebsiella, Pseudomonas, Staphylococcus, and Stenotrophomonas. The enzyme (amylolytic, proteolytic, and lipolytic) and antimicrobial activities against saprophytic and pathogenic microorganisms of the identified microorganisms were determined. The adhesive ability to human epithelial cells was determined for the first time. With the most significant anti-inflammatory, immunomodulatory properties, i.e., with the most substantial inhibition of the production of the cytokine IL-8 (pg/mL) and induction of the synthesis of transforming growth factor beta TGF-beta (pg/mL) are strains Bacillus subtilis 0-2 and B. thuringiensis B62. These two strains are potentially promising as probiotics alone or in combination with lactic acid bacteria to enhance probiotic activity and anti-inflammatory properties and to be used in biotechnological production.