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Ultrason Sonochem ; 60: 104788, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31550644


To prevent possible spread of nosocomial infections - HAI (Healthcare Acquired Infections) in healthcare facilities, Antibacterial textiles are developed. This carried out study has been conducted to assess the feasibility of the method of obtaining antibacterial coatings on textile materials. Specifically, the sol-gel method for synthesis of titanium dioxide nanoparticles in combination with zinc oxide nanoparticles from titanyl sulphate and zinc nitrate hexahydrate has been investigated. During the synthesis of titanium dioxide nanoparticles in combination with the zinc oxide nanoparticles, the coated textile material showed stable antibacterial properties with a suppression level ofEscherichia coliof more than 99.99%. The method has been tested on a semi-industrial scale in roll-to-roll experimentby applying homogenous coatings at a speed of 1,5 m per minute.

Probiotics Antimicrob Proteins ; 12(3): 1139-1148, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31650413


Research of human microbiome demonstrates that in order to develop next generation of probiotic agents, it is necessary to choose bacterial strains featured by special properties, such as the ability of the cells to attach to intestinal walls, resistance to bile and acids, bacteriocin synthesis, antioxidative and antipathogenic activity, and survivability in intestines. Thirty-three strains of lactic acid bacteria of Lactobacillus and Lactococcus genera from the Lomonosov Moscow State University Collection of Microorganisms (CM MSU) have been tested for important probiotic properties which assist these bacteria to settle effectively in intestines: cell adhesion, ability to form biofilms, agglutination with lectin (concanavalin A), and antimicrobial activity. The results of experiments clearly demonstrate that all these properties can be classified as strain characteristics and differ even within the same species. Besides the cultures of Lactobacillus with good agglutination ability with concanavalin A (Lact. caucasicus CM MSU 155, Lact. brevis CM MSU 521), we also discovered strains with high adhesion properties (Lact. acidophilus CM MSU 146-89% affinity for hexadecane; Lact. paracasei CM MSU 527-85%; Lact. plantarum CM MSU 508-78%; Lact. caucasicus CM MSU 155-70%; and Lact. delbrueckii CM MSU 571-57%), biofilm formation ability with a hydrophobic carrier (Lact. plantarum CM MSU 588-OD590 of crystal violet extracts = 1.336; Lact. brevis CM MSU 521-OD590 = 1.207; and Lact. brevis CM MSU 535-OD590 = 1.151), and with high antimicrobial activity specially to Staphylococcus aureus. Lact. brevis CM MSU 521 possesses the best property combination, which makes it potentially applicable as a very good lactic acid probiotic strain.

Antibiose , Lactobacillus/metabolismo , Probióticos , Aderência Bacteriana , Biofilmes , Probióticos/metabolismo , Staphylococcus aureus
Adv Exp Med Biol ; 897: 103-11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26566644


103 strains of lactic acid bacteria of Lactobacillus genus were isolated from natural sources and identified for genus and species level with API tests and 16S rRNA sequencing. However, only 27 strains from isolated cultures demonstrated a high stability to gastric stress and from that - only 15 strains were highly resistant to intestinal stress. Results indicated that only some isolated cultures of lactobacilli possessed potential probiotical properties and could serve as new probiotics for dairy industry with high resistance to gastro-intestinal stresses.

Lactobacillus , Probióticos , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Estresse Fisiológico , Animais , Indústria de Laticínios , Microbiologia de Alimentos , Humanos , Lactobacillus/classificação , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/isolamento & purificação , Probióticos/classificação , Probióticos/isolamento & purificação
Arch Microbiol ; 188(6): 655-64, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17687544


Germination of orchid seeds is a complex process. In this paper we focus on interactions between the host-plant and its bacterial partners via indole-3-acetic acid (IAA). Originally isolated from the roots of the epiphytic orchid Dendrobium moschatum, the strains of Rhizobium, Microbacterium, Sphingomonas, and Mycobacterium genera were among the most active IAA producers. Addition of exogenous tryptophan significantly enhanced auxin formation both in mineral and complex media. The presence of IAA and indole-3-acetaldehyde was confirmed by HPLC. Indole-3-pyruvic and indole-3-lactic acids were also detected in supernatants of culture filtrates of Sphingomonas sp., Rhizobium sp., and Microbacterium sp., while indole-3-acetamide was identified only in Mycobacterium sp. Some concentration- and strain-dependent effects of exogenous IAA on bacterial development were also established. Treatment of the cultures with 10 and 100 microg/ml of auxin resulted in an increase in microbial yield. None of the investigated strains was able to utilize IAA as a source of carbon and energy. Furthermore, inoculation of D. moschatum seeds with Sphingomonas sp. and Mycobacterium sp. resulted in considerable enhancement of orchid seeds germination. This growth-promoting activity was observed in the absence of any plant growth stimulators or mycorrhizal fungi, usually required for orchid germination.

Bactérias/metabolismo , Dendrobium/microbiologia , Ácidos Indolacéticos/metabolismo , Sementes/microbiologia , Bactérias/genética , Cromatografia Líquida de Alta Pressão/métodos , Contagem de Colônia Microbiana , Dendrobium/fisiologia , Germinação , Reguladores de Crescimento de Plantas/metabolismo , RNA Ribossômico 16S/genética , Sementes/fisiologia , Simbiose
Microbiol Res ; 162(1): 69-76, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17140781


Associative bacteria of terrestrial (Paphiopedilum appletonianum) and epiphytic (Pholidota articulata) tropical orchids were investigated. Microbial community of epiphytic plant differed from that of the terrestrial one. Streptomyces, Bacillus, Pseudomonas, Burkholderia, Erwinia and Nocardia strains populated Paphiopedilum roots, whereas Pseudomonas, Flavobacterium, Stenotrophomonas, Pantoea, Chryseobacterium, Bacillus, Agrobacterium, Erwinia, Burkholderia and Paracoccus strains colonized Pholidota roots. Endophytic bacteria populations were represented with less diversity: Streptomyces, Bacillus, Erwinia and Pseudomonas genera were isolated from P. appletonianum, and Pseudomonas, Bacillus, and Flavobacterium genera were isolated from Ph. articulata. Microorganisms produced indole-3-acetic acid (IAA). Variations in its biosynthesis among the strains of the same genus were also observed. The highest auxin level was detected during the stationary growth phase. Biological activity of microbial IAA was proved by treatment of kidney bean cuttings with bacterial supernatants, revealing considerable stimulation of root formation and growth.

Bactérias/classificação , Bactérias/isolamento & purificação , Ácidos Indolacéticos/metabolismo , Orchidaceae/microbiologia , Raízes de Plantas/microbiologia , Bactérias/genética , Bactérias/metabolismo , Biodiversidade , DNA Bacteriano/química , DNA Bacteriano/genética , Genes de RNAr , Ácidos Indolacéticos/farmacologia , Dados de Sequência Molecular , Phaseolus/efeitos dos fármacos , Phaseolus/crescimento & desenvolvimento , Filogenia , Reguladores de Crescimento de Plantas/farmacologia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico