Nadya Armenova

Ms. Nadya Armenova

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 July 2024 in Foods
Verified
Journal Article
Open access
PDF file
AAAlexander Arsov
Alexander Arsov
Lidia TsigoriynaLidia Tsigoriyna
Lidia Tsigoriyna
Daniela BatovskaDaniela Batovska
Daniela Batovska
NANadya Armenova
Nadya Armenova
WMWanmeng Mu
Wanmeng Mu
Penka PetrovaPenka Petrova
Penka Petrova
Antinutrients, also known as anti-nutritional factors (ANFs), are compounds found in many plant-based foods that can limit the bioavailability of nutrients or can act as precursors to toxic substances. ANFs have controversial effects on human health, depending mainly on their concentration. While the positive effects of these compounds are well documented, the dangers they pose and the approaches to avoid them have not been discussed to the same extent. There is no dispute that many ANFs negatively alter the absorption of vitamins, minerals, and proteins in addition to inhibiting some enzyme activities, thus negatively affecting the bioavailability of nutrients in the human body. This review discusses the chemical properties, plant bioavailability, and deleterious effects of anti-minerals (phytates and oxalates), glycosides (cyanogenic glycosides and saponins), polyphenols (tannins), and proteinaceous ANFs (enzyme inhibitors and lectins). The focus of this study is on the possibility of controlling the amount of ANF in food through fermentation. An overview of the most common biochemical pathways for their microbial reduction is provided, showing the genetic basis of these phenomena, including the active enzymes, the optimal conditions of action, and some data on the regulation of their synthesis.

9 March 2023 in Foods
Verified
Journal Article
Open access
PDF file
NANadya Armenova
Nadya Armenova
Lidia TsigoriynaLidia Tsigoriyna
Lidia Tsigoriyna
AAAlexander Arsov
Alexander Arsov
KPKaloyan Petrov
Kaloyan Petrov
Penka PetrovaPenka Petrova
Penka Petrova
The treatment of agricultural areas with pesticides is an indispensable approach to improve crop yields and cannot be avoided in the coming decades. At the same time, significant amounts of pesticides remain in food and their ingestion causes serious damage such as neurological, gastrointestinal, and allergic reactions; cancer; and even death. However, during the fermentation processing of foods, residual amounts of pesticides are significantly reduced thanks to enzymatic degradation by the starter and accompanying microflora. This review concentrates on foods with the highest levels of pesticide residues, such as milk, yogurt, fermented vegetables (pickles, kimchi, and olives), fruit juices, grains, sourdough, and wines. The focus is on the molecular mechanisms of pesticide degradation due to the presence of specific microbial species. They contain a unique genetic pool that confers an appropriate enzymological profile to act as pesticide detoxifiers. The prospects of developing more effective biodetoxification strategies by engaging probiotic lactic acid bacteria are also discussed.

27 December 2025 in Journal of Fungi
Verified
Journal Article
Open access
PDF file
NANadya Armenova
Nadya Armenova
Lidia TsigoriynaLidia Tsigoriyna
Lidia Tsigoriyna
AAAlexander Arsov
Alexander Arsov
SSStefan Stefanov
Stefan Stefanov
KPKaloyan Petrov
Kaloyan Petrov
Penka PetrovaPenka Petrova
Penka Petrova
Fungal phytopathogens cause significant global crop losses and remain a constant obstacle to sustainable food production. Biological control has become a vital alternative to synthetic fungicides, supported by the wide variety of antifungal molecules produced by bacteria, fungi, yeasts, and plants. This review consolidates current knowledge on the main classes of microbial secondary metabolites—particularly cyclic lipopeptides and polyketides from Bacillus, Pseudomonas, Streptomyces, Trichoderma, and related generа. It emphasizes their structural diversity, biosynthetic pathways, regulatory networks, and antifungal mechanisms. These molecules, including iturins, fengycins, surfactins, syringomycins, candicidins, amphotericin analogs, peptaibols, and epipolythiodioxopiperazines, target fungal membranes, mitochondria, cell walls, and signaling systems, offering broad activity against damaging pathogens such as Fusarium, Botrytis, Magnaporthe, Colletotrichum, Phytophthora, and Rhizoctonia. The plant-derived antifungal metabolites include essential volatile compounds that complement microbial agents and are increasingly important in eco-friendly crop protection. Recent progress in genomics, metabolic engineering, and synthetic biology has accelerated strain improvement and the discovery of new bioactive compounds. At the same time, global market analyses indicate rapid growth in microbial biofungicides driven by regulatory changes and consumer demand.

13 December 2024 in Fermentation
Verified
Journal Article
Open access
PDF file
Lidia TsigoriynaLidia Tsigoriyna
Lidia Tsigoriyna
SSStefan Stefanov
Stefan Stefanov
NANadya Armenova
Nadya Armenova
Penka PetrovaPenka Petrova
Penka Petrova
KPKaloyan Petrov
Kaloyan Petrov
The global transition to a sustainable bioeconomy requires the engagement of renewable and cost-effective substrates to obtain valuable bio-based products. Inulin-rich plant materials have promising applications in white biotechnology. This review evaluates the potential of converting inulin through an integrated biorefinery into high-value products by microbial fermentation. It describes the methods for raw biomass and inulin pretreatment, the possibilities of simultaneous saccharification and fermentation (SSF), and the use of wild-type and genetically modified microbial strains. The bioconversion of inulin enables the efficient synthesis of biofuels such as ethanol, butanol, and 2,3-butanediol and biochemicals such as lactic, citric, and poly-γ-glutamic acid. By analyzing the advances in inulin hydrolysis methods, microbial engineering, and bioprocess optimization approaches, this review highlights the broad applicability of inulin in the biorefinery context as a multifunctional, sustainable substrate, which contributes to the development of the circular economy.

9 January 2024 in Fermentation
Verified
Journal Article
Open access
PDF file
AAAlexander Arsov
Alexander Arsov
NANadya Armenova
Nadya Armenova
EGEmanoel Iliev Gergov
Emanoel Iliev Gergov
KPKaloyan Petrov
Kaloyan Petrov
Penka PetrovaPenka Petrova
Penka Petrova
Representatives of the genus Bacillus have been established as one of the most important industrial microorganisms in the last few decades. Genetically modified B. subtilis and, to a lesser extent, B. licheniformis, B. amyloliquefaciens, and B. megaterium have been used for the heterologous expression of numerous proteins (enzymes, vaccine components, growth factors), platform chemicals, and other organic compounds of industrial importance. Vectors designed to work in Bacillus spp. have dramatically increased in number and complexity. Today, they provide opportunities for genetic manipulation on every level, from point mutations to systems biology, that were impossible even ten years ago. The present review aims to describe concisely the latest developments in the shuttle, integrative, and CRISPR-Cas9 vectors in Bacillus spp. as well as their application for large-scale bioengineering with the prospect of producing valuable compounds on an industrial scale. Genetic manipulations of promoters and vectors, together with their impact on secretory and metabolic pathways, are discussed in detail.

Verified
Journal Article
Open access
PDF file
AAAlexander Arsov
Alexander Arsov
Penka PetrovaPenka Petrova
Penka Petrova
MGMaria Gerginova Gerginova
Maria Gerginova Gerginova
Lidia TsigoriynaLidia Tsigoriyna
Lidia Tsigoriyna
NANadya Armenova
Nadya Armenova
KPKaloyan Petrov
Kaloyan Petrov
The unique fuel characteristics of butanol and the possibility of its microbial production make it one of the most desirable environmentally friendly substitutes for petroleum fuels. However, the highly toxic nature of 1-butanol to the bacterial strains makes it unprofitable for commercial production. By comparison, 2-butanol has similar fuel qualities, and despite the difficulties in its microbial synthesis, it holds promise because it may be less toxic. This paper is the first comprehensive study to compare bacterial tolerance to different butanol isomers by examining the growth of 31 bacterial strains under 1-butanol and 2-butanol stress conditions. The presented results reveal that all tested strains showed a higher tolerance to 2-butanol than to 1-butanol at each solvent concentration (1%, 2%, and 3% v/v). Moreover, with an increased solvent concentration, bacterial cells lost their resistance to 1-butanol more rapidly than to 2-butanol. A comparison of the transcriptome profiles of the reference strains Bacillus subtilis ATCC 168 and E. coli ATCC 25922 disclosed a specific response to butanol stress. Most notably, in the presence of 2-butanol E. coli ATCC 25922 showed a reduced expression of genes for chaperones, efflux pumps, and the flagellar apparatus, as well as an enhancement of membrane and electron transport. B. subtilis, with 2-butanol, did not perform emergency sporulation or escape, as some global transcriptional stress response regulators were downregulated. The overexpression of ribosomal RNAs, pyrimidine biosynthesis genes, and DNA- and RNA-binding proteins such as pcrA and tnpB was crucial in the response.