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Item type:Publication, Access status: with files , Biodegradation of polyhydroxyalkanoates: current state and future prospects(Frontiers Media S.A., 2025); ;Tadevosyan, Mane; ; Polyhydroxyalkanoates (PHAs) are biobased and biodegradable polymers that offer a sustainable alternative to conventional plastics, addressing the escalating concerns over plastic pollution. While their environmental advantages are well-documented, the efficient degradation of PHAs in natural and engineered environments remains a critical component of their lifecycle. This review provides a comprehensive overview of PHA-degrading bacteria isolated from diverse ecosystems and highlights the pivotal role of PHA depolymerases in achieving PHA circularity. Microbial adaptation to diverse environmental conditions, such as extreme temperatures, salinity, and pH, significantly influences enzymes properties, including the stability, activity, and substrate specificity of PHA-degrading enzymes. These adaptations often enhance enzyme, performance, enabling functionality under challenging conditions. Consequently, extremophilic microorganisms are invaluable resources for discovering and engineering robust PHA depolymerases for industrial and environmental applications. This review underscores the urgent need for further research to improve the ecological and economic sustainability of PHA waste management.Publicationtype: Review Article6 14 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Detergent-resistant α-amylase derived from Anoxybacillus karvacharensis K1 and its production based on whey(Nature Publishing Group, 2024-12-01) ;Ghevondyan, Diana ;Soghomonyan, Tigran ;Hovhannisyan, Pargev; In the field of biotechnology, the utilization of agro-industrial waste for generating high-value products, such as microbial biomass and enzymes, holds significant importance. This study aimed to produce recombinant α-amylase from Anoxybacillus karvacharensis strain K1, utilizing whey as an useful growth medium. The purified hexahistidine-tagged α-amylase exhibited remarkable homogeneity, boasting a specific activity of 1069.2 U mg−1. The enzyme displayed its peak activity at 55 °C and pH 6.5, retaining approximately 70% of its activity even after 3 h of incubation at 55 °C. Its molecular weight, as determined via SDS-PAGE, was approximately 69 kDa. The α-amylase demonstrated high activity against wheat starch (1648.8 ± 16.8 U mg−1) while exhibiting comparatively lower activity towards cyclodextrins and amylose (≤ 200.2 ± 16.2 U mg−1). It exhibited exceptional tolerance to salt, withstanding concentrations of up to 2.5 M. Interestingly, metal ions and detergents such as sodium dodecyl sulfate (SDS), Triton 100, Triton 40, and Tween 80, 5,5ʹ-dithio-bis-[2-nitrobenzoic acid (DNTB), β-mercaptoethanol (ME), and dithiothreitol (DTT) had no significant inhibitory effect on the enzyme’s activity, and the presence of CaCl2 (2 mM) even led to a slight activation of the recombinant enzyme (1.4 times). The Michaelis constant (Km) and maximum reaction rate (Vmax), were determined using soluble starch as a substrate, yielding values of 1.2 ± 0.19 mg mL−1 and 1580.3 ± 183.7 μmol mg−1 protein min−1, respectively. Notably, the most favorable conditions for biomass and recombinant α-amylase production were achieved through the treatment of acid whey with β-glucosidase for 24 h.Publicationtype: Journal Article9 120 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Mining thermophiles for biotechnologically relevant enzymes: evaluating the potential of European and Caucasian hot springs(Springer, 2024-04); ; ; ; The development of sustainable and environmentally friendly industrial processes is becoming very crucial and demanding for the rapid implementation of innovative bio-based technologies. Natural extreme environments harbor the potential for discovering and utilizing highly specific and efficient biocatalysts that are adapted to harsh conditions. This review focuses on extremophilic microorganisms and their enzymes (extremozymes) from various hot springs, shallow marine vents, and other geothermal habitats in Europe and the Caucasus region. These hot environments have been partially investigated and analyzed for microbial diversity and enzymology. Hotspots like Iceland, Italy, and the Azores harbor unique microorganisms, including bacteria and archaea. The latest results demonstrate a great potential for the discovery of new microbial species and unique enzymes that can be explored for the development of Circular Bioeconomy. Different screening approaches have been used to discover enzymes that are active at extremes of temperature (up 120 °C), pH (0.1 to 11), high salt concentration (up to 30%) as well as activity in the presence of solvents (up to 99%). The majority of published enzymes were revealed from bacterial or archaeal isolates by traditional activity-based screening techniques. However, the latest developments in molecular biology, bioinformatics, and genomics have revolutionized life science technologies. Post-genomic era has contributed to the discovery of millions of sequences coding for a huge number of biocatalysts. Both strategies, activity- and sequence-based screening approaches, are complementary and contribute to the discovery of unique enzymes that have not been extensively utilized so far.Publicationtype: Review ArticleScopus© Citations 1 54 81