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Elena Efremenko

Bio: Elena Efremenko is an academic researcher from Moscow State University. The author has contributed to research in topics: Chemistry & Medicine. The author has an hindex of 23, co-authored 124 publications receiving 1594 citations. Previous affiliations of Elena Efremenko include Edgewood Chemical Biological Center & Russian Academy of Sciences.


Papers
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Journal ArticleDOI
TL;DR: Immobilized Clostridium cells were demonstrated to be suitable for multiple reuses (for a minimum of five cycles) in ABE fermentation for producing biofuels from pretreated microalgal biomass.

147 citations

Journal ArticleDOI
TL;DR: This review summarizes current information on enzymes of different classes to convert various mycotoxins and the importance of multifunctional enzyme combinations for detoxification of mycot oxins is posed.
Abstract: Mycotoxins are highly dangerous natural compounds produced by various fungi. Enzymatic transformation seems to be the most promising method for detoxification of mycotoxins. This review summarizes current information on enzymes of different classes to convert various mycotoxins. An in-depth analysis of 11 key enzyme mechanisms towards dozens of major mycotoxins was realized. Additionally, molecular docking of mycotoxins to enzymes' active centers was carried out to clarify some of these catalytic mechanisms. Analyzing protein homologues from various organisms (plants, animals, fungi, and bacteria), the prevalence and availability of natural sources of active biocatalysts with a high practical potential is discussed. The importance of multifunctional enzyme combinations for detoxification of mycotoxins is posed.

84 citations

Journal ArticleDOI
TL;DR: N nano‐OPH is bioavailable after intramuscular (im), intraperitoneal (ip) and even transbuccal (tb) administration, and has shown ability to protect animals from exposure to a pesticide, paraoxon and a warfare agent, VX.

72 citations

Journal ArticleDOI
TL;DR: A higher OA productivity was reached via simultaneous enzymatic saccharification and microbial fermentation (SSF) of same raw materials as compared to their separate enzyme-based hydrolysis and fermentation of accumulated reducing sugars (SHF).

66 citations

Journal ArticleDOI
TL;DR: Comparative analysis of purification using Co2+-IDA–PAA and Ni-nitrilotriacetic acid–agarose showed obvious advantages of the former in process time, specific activity of purified enzyme, and simplicity of adsorbent regeneration.
Abstract: Organophosphate hydrolase containing hexahistidine tag at the N-terminus of recombinant protein (His6-OPH) and expressed in Escherichia coli cells was purified using supermacroporous polyacrylamide-based monolith columns with immobilized metal affinity matrices [Me2+-iminodiacetic acid (IDA)–polyacrylamide cryogel (PAA) and Me2+-N,N,N’-tris (carboxymethyl) ethylendiamine (TED)–PAA]. Enzyme preparation with 50% purity was obtained by direct chromatography of nonclarified cell homogenate, whereas the combination of addition of 10 mM imidazole to buffers for cell sonication and sample loading, the use of precolumn with IDA–PAA matrix noncharged with metal ions, and the application of high flow rate provided the 99% purity of enzyme isolated directly from crude cell homogenate. Co2+-IDA–PAA provided the highest level of selectivity for His6-OPH. Comparative analysis of purification using Co2+-IDA–PAA and Ni-nitrilotriacetic acid–agarose showed obvious advantages of the former in process time, specific activity of purified enzyme, and simplicity of adsorbent regeneration.

64 citations


Cited by
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Reference EntryDOI
31 Oct 2001
TL;DR: The American Society for Testing and Materials (ASTM) as mentioned in this paper is an independent organization devoted to the development of standards for testing and materials, and is a member of IEEE 802.11.
Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

3,792 citations

Journal ArticleDOI
TL;DR: This review systematically introduces the classification, catalytic mechanism, activity regulation as well as recent research progress of nanozymes in the field of biosensing, environmental protection, and disease treatments, etc. in the past years.
Abstract: Because of the high catalytic activities and substrate specificity, natural enzymes have been widely used in industrial, medical, and biological fields, etc. Although promising, they often suffer from intrinsic shortcomings such as high cost, low operational stability, and difficulties of recycling. To overcome these shortcomings, researchers have been devoted to the exploration of artificial enzyme mimics for a long time. Since the discovery of ferromagnetic nanoparticles with intrinsic horseradish peroxidase-like activity in 2007, a large amount of studies on nanozymes have been constantly emerging in the next decade. Nanozymes are one kind of nanomaterials with enzymatic catalytic properties. Compared with natural enzymes, nanozymes have the advantages such as low cost, high stability and durability, which have been widely used in industrial, medical, and biological fields. A thorough understanding of the possible catalytic mechanisms will contribute to the development of novel and high-efficient nanozymes, and the rational regulations of the activities of nanozymes are of great significance. In this review, we systematically introduce the classification, catalytic mechanism, activity regulation as well as recent research progress of nanozymes in the field of biosensing, environmental protection, and disease treatments, etc. in the past years. We also propose the current challenges of nanozymes as well as their future research focus. We anticipate this review may be of significance for the field to understand the properties of nanozymes and the development of novel nanomaterials with enzyme mimicking activities.

1,549 citations

Journal ArticleDOI
TL;DR: Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are discussed, and pathways for degradation of some organophosphorus compounds by microorganisms are proposed.
Abstract: Synthetic organophosphorus compounds are used as pesticides, plasticizers, air fuel ingredients and chemical warfare agents. Organophosphorus compounds are the most widely used insecticides, accounting for an estimated 34% of world-wide insecticide sales. Contamination of soil from pesticides as a result of their bulk handling at the farmyard or following application in the field or accidental release may lead occasionally to contamination of surface and ground water. Several reports suggest that a wide range of water and terrestrial ecosystems may be contaminated with organophosphorus compounds. These compounds possess high mammalian toxicity and it is therefore essential to remove them from the environments. In addition, about 200 000 metric tons of nerve (chemical warfare) agents have to be destroyed world-wide under Chemical Weapons Convention (1993). Bioremediation can offer an efficient and cheap option for decontamination of polluted ecosystems and destruction of nerve agents. The first micro-organism that could degrade organophosphorus compounds was isolated in 1973 and identified as Flavobacterium sp. Since then several bacterial and a few fungal species have been isolated which can degrade a wide range of organophosphorus compounds in liquid cultures and soil systems. The biochemistry of organophosphorus compound degradation by most of the bacteria seems to be identical, in which a structurally similar enzyme called organophosphate hydrolase or phosphotriesterase catalyzes the first step of the degradation. organophosphate hydrolase encoding gene opd (organophosphate degrading) gene has been isolated from geographically different regions and taxonomically different species. This gene has been sequenced, cloned in different organisms, and altered for better activity and stability. Recently, genes with similar function but different sequences have also been isolated and characterized. Engineered microorganisms have been tested for their ability to degrade different organophosphorus pollutants, including nerve agents. In this article, we review and propose pathways for degradation of some organophosphorus compounds by microorganisms. Isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation are discussed. The major achievements and technological advancements towards bioremediation of organophosphorus compounds, limitations of available technologies and future challenge are also discussed.

954 citations

Journal ArticleDOI
TL;DR: This review will discuss lactic acid producers with relation to their fermentation characteristics and metabolism, and introduces inexpensive fermentative substrates, such as dairy products, food and agro-industrial wastes, glycerol, and algal biomass alternatives to costly pure sugars and food crops.

762 citations