2017, Vol. 81 No. 2
Stały URI dla kolekcjihttp://hdl.handle.net/11652/5432
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Pozycja Safety of workers exposed to harmful airborne bioaerosols – legal status and innovations(Wydawnictwo Politechniki Łódzkiej, 2017) Majchrzycka, Katarzyna; Okrasa, Małgorzata; Szulc, Justyna; Gutarowska, BeataFiltering respiratory protective equipment is commonly used for protection against bioaerosols in industrial workplaces. However, the EU legislation does not specify the requirements for its antimicrobial properties. The result is that in the market there is no equipment available that would ensure complete safety of workers exposed to inhalation of harmful bioaerosols. This is particularly important in the case of equipment intended for multiple and long-term use. The aim of this study was to develop an innovative filtering half mask for the protection of respiratory tract that would have confirmed antimicrobial properties. The half mask was tested for compliance with EN 149:2001+A1:2009, and the survival rate of microorganisms in nonwovens was determined (E. coli bacteria and A. niger moulds). The reduction in the number of E. coli bacteria was 98.69% and the reduction in the number of A. niger moulds was 67.68% after 32 h of storage under conditions simulating the conditions of use of the equipment. It was found that the biocidal activity of the half mask is sufficient to ensure a significant reduction in the number of microorganisms during its long-term use in the workplace. This in turn means that continuous disinfection of respiratory protective equipment would be maintained even without employees’ intervention, which is not possible in case of standard respiratory protective equipment.Pozycja Production of co-immobilized dextransucrase and dextranase preparations and their application in isomalto-oligosaccharides synthesis(Wydawnictwo Politechniki Łódzkiej, 2017) Sikora, Barbara; Kubik, Celina; Bielecki, StanisławDextransucrase (DS) from Leuconostoc mesenteroides and dextranase (DN) from Penicillium funiculosum were co-immobilized by entrapment in calcium alginate and used to produce isomaltooligosaccharides (IMOs) from sucrose. DS convert sucrose into dextran, which is the substrate for DN, so that IMOs are products of dextran hydrolysis. Before the co-immobilization DS was cross-linked with glutardialdehyde (GA), while DN was adsorbed on hydroxyapatite (HAp). Cross-linking was essential for the stability of DS and pre-immobilization of DN to prevent enzyme from leaking out of the alginate beads. Operational stability of co-immobilized preparations of DS and DN was estimated based on amounts of isomaltose and isomaltotriose formed during successive 24h processes of IMOs synthesis, carried out at 30oC, pH 5.4 and 200 rpm in 10% (w/v) sucrose solutions. Preparation characterized by the initial DS/DN activities ratio of 1/14 was found to maintain these activities at least 100 h of IMOs synthesis (5 repeated batch reaction).Pozycja A comparison of two enzymatic methods of clinical dextran production(Wydawnictwo Politechniki Łódzkiej, 2017) Sikora, Barbara; Kubik, Celina; Bielecki, StanisławThe aim of this study was to evaluate and compare of the two enzymatic methods of clinical dextran production were compared. The reactions were performed at 30°C and pH 5.4 in solutions containing different amounts of sucrose, using dextransucrase (DS, in the presence of dextranase (D) (method 1) or acceptor dextrans (method 2). The activity of Leuconostoc mesenteroides L dextransucrase (DS), which converts sucrose to dextran, was 0.4 U ml-1 in both the methods. As much as 53-56% of clinical dextran fractions were obtained for 28 h from 10% sucrose solutions, which contained 1.5% or 2.5% acceptor dextrans with molecular mass of 10 and 15 kDa, respectively. Approximately 50% of these fractions was obtained (also in 28 h) from 10% sucrose solutions by using 0.004 U ml-1 of DN, added to reaction mixtures 5 h later than Our experiments indicate that the clinical dextran can be efficiently produced by using both the compared methods, which employ either acceptor dextrans with definite molecular mass, or the dextranase. Because consumption of the latter enzyme is rather small, and it is easily available, thus this method should be attractive for clinical dextran manufacturers.Pozycja Zinc and nano-ZnO – influence on living organisms(Lodz University of Technology Press, 2017) Mielcarz-Skalska, Lidia; Smolińska, BeataThe use of zinc is very common in many industries. The multitude of advantages, and capabilities make use of different forms of penetration of zinc into the environment. Due to its ability to migrate, zinc is also accumulated in living organisms. Zn is an essential trace element but both the deficiency or excess are extremely dangerous for living organisms. Nowadays nanozinc has been increasingly used. Nanozinc is a component of daily used products, like plastics, ceramics, glass, cement, rubber, foods and many others. This leads to spreading nanozinc the environment with the possibility of its penetration into living organisms. This article is a review of the impact of zinc and zinc nanoparticles on a variety of organisms: ranging from microorganisms through plants and animals, to people.Pozycja In vitro anti-adherence effect of probiotic Lactobacillus strains on human enteropathogens(Lodz University of Technology Press, 2017) Nowak, Adriana; Motyl, IlonaProbiotic bacteria possess great potential for producing antimicrobial substances that inhibit and control pathogenic bacteria in the human gastrointestinal tract. The aim of this study was to determine the anti-adherence properties of the probiotic Lactobacillus strains Lb. rhamnosus ŁOCK 0900, Lb. rhamnosus ŁOCK 0908, and Lb. casei ŁOCK 0919 (individually and in a 1:1:2 mixture) against the reference pathogens Clostridium difficile (ATCC 9689), Enterococcus faecalis (ATCC 29212), Listeria monocytogenes (ATCC 19115), and Staphylococcus aureus (ATCC 6538) using the Caco-2 human colon adenocarcinoma cell line. The mixture of probiotic strains inhibited the adherence of all pathogens, from 10.2% for E. faecalis ATCC 29212 to 97.2% for L. monocytogenes ATCC 19115. Of all the tested probiotic strains, Lb. casei ŁOCK 0919 reduced the adherence of S. aureus ATCC 6538 to the greatest extent (by 45.9%). These results suggest that adherence inhibition may involve competition for eukaryotic cell receptors and probiotic bacteria could protect the host cells from pathogen colonization and disease.