[Inhibition of adherence of Corynebacterium diphtheriae to human buccal epithelium by glycoside hydrolases from marine hydrobiontes].

A possibility of adhesion inhibition of Corynebacterium diphtheriae to human buccal epithelium by glycoside hydrolases of marine hydrobiontes was investigated using alpha-galactosidase from marine bacterium Pseudoalteromonas sp. KMM 701, total enzyme preparation and beta-1,3-glucanase from marine fungi Chaetomium, total enzyme preparation and beta-1,3-glucanase from marine mollusk Littorina kurila, and total enzyme preparation from crystalline style of marine mollusk Spisula sachalinensis were used. The enzymes were added to test-tubes containing buccal epithelial cells and/or the toxigenic bacterial strain C. diphtheriae No 1129, v. gravis. All the investigated enzymes were able to abort C. diphtheriae adherence, to human buccal epithelocytes. Inhibition of adhesion was more pronounced in the case of treatment of epithelocytes with highly purified enzymes of marine hydrobiontes in comparison with total enzyme preparations. The significant inhibition of C. diphtheriae adhesion was observed when the enzymes were added to the epithelocytes with the attached microorganisms. The results obtained show that glycoside hydrolases of marine hydrobiontes degrade any carbohydrates expressed on cell surface of bacterium or human buccal epithelocytes, impair unique lectin-carbohydrate interaction and prevent the adhesion.

[Distribution of intracellular fucoidan hydrolases among marine bacteria of the family Flavobacteriaceae].

A search for fucoidan-degrading enzymes and other O-glycosylhydrolases has been performed among 51 strains of marine bacteria of the family Flavobacteriaceae isolated from red, green, and brown algae, as well as from the sea urchin Strongylocentrotus intermedius and the holothurian Apostichopus japonicus. Over 40% of the studied strains synthesized fucoidanases. The marine bacteria Mesonia algae KMM 3909(T) (an isolate from green alga Acrosiphonia sonderi), as well as Maribacter sp. KMM 6211 and Gramella sp. KMM 6054 (associants of the sea urchin S. intermedius), were the best producers of fucoidanases. Xylose effectively induced the biosynthesis of fucoidanases in these strains. None of the 15 strains of marine bacteria belonging to the genus Arenibacter produced polysaccharide hydrolases.

[Characterization of marine bacteria Pseudoalteromonas citrea degradating fucoidan]. / Kharakteristika morskikh bakterii Pseudoalteromonas citrea degradiruiushchikh fukoidan.

Two strains KMM 3296 and KMM 3298, isolated from the surface of brown algae Chorda filum and Fucus evanescens thalli and strain KMM 3297, isolated from celomic fluid of holoturian Apostichopus japonicus, were identified as Pseudoalteromonas citrea on the basis of pheno-, geno- and phylotypic features. The studied bacteria were different from other bacteria of the species as to their ability to destruct sulphated polysaccharides of brown algae, fucoidans.

[Degradation of fucoidan by the marine proteobacterium Pseudoalteromonas citrea]. / Osobennosti degradatsii fukoidana morskimi proteobakteriiami Pseudoalteromonas citrea.

It was found that Pseudoalteromonas citrea strains KMM 3296 and KMM 3298 isolated from the brown algae Fucus evanescens and Chorda filum, respectively, and strain 3297 isolated from the sea cucumber Apostichopus japonicus are able to degrade fucoidans. The fucoidanases of these strains efficiently degraded the fucoidan of brown algae at pH 6.5-7.0 and remained active at 40-50 degrees C. The endo-type hydrolysis of fucoidan resulted in the formation of sulfated alpha-L-fucooligosaccharides. The other nine strains of P. citrea studied (including the type strain of this species), which were isolated from other habitats, were not able to degrade fucoidan.

[Screening of marine bacteria for fucoidan hydrolases]. / Poisk fukoidan-gidrolaz sredi morskikh mikroorganizmov.

Twenty-five strains of epiphytic marine bacteria isolated from the brown algae Fucus evanescens and Chorda filum and fifty-three bacteria isolated from the sea cucumber Apostichopus japonicus were screened for fucoidanases using fucoidans prepared from the brown algae F. evanescens, Laminaria cichorioides, and L. japonica. Eighteen bacterial epiphytes and thirty-eight bacterial isolates from the sea cucumber were found to contain fucoidanases, which were able to hydrolyze either all of the fucoidans studied or some of them. Bacteria of the genera Cytophaga and Alteromonas/Pseudoalteromonas exhibited the highest fucoidanase activities, which, however, did not exceed the activity of fucoidanases from the already known sources.

[Determination and identification of beta-1,3;1,6-glycooligosaccharides in laminarioligosaccharide mixtures by means of enzymologic transglycosylation. Oligosaccharides with degree of polymerization of 5 and 6]. / Fermentativnoe transglikozilirovanie kak sposob obnaruzheniia i identifikatsii beta-1,3;1,6-gliukooligosakharidov v smesi laminarioligosakharidov. Oligosakharidy so stepen'iu polimerizatsii 5 i 6.

1-->3; 1-->6-beta-D-Glucooligosaccharides with polymerization degree of 5-6 were obtained from laminaran and analyzed by the previously developed method [1] by using them as donors and p-nitrophenyl beta-D-glucoside as the acceptor in the transglycosylation reaction catalysed by endo-1-->3-beta-D-glucanase LIV. The resulting homologous p-nitrophenyl beta-1,3-laminarioligosides with polymerization degree of 2-6 and the corresponding derivatives of mixed beta-1,3; 1,6-glucooligosaccharides with the same polymerization degree were analyzed by HPLC. The latter compounds exhibited higher retention times than the former with the same polymerization degree. Isomeric tetra-, penta-, and hexameric compounds were detected, and some of them were structurally characterized by means of NMR. The suggested method of analysis of oligosaccharide mixtures is simple, informative, and consumes a minimal quantity of sample.

[Distribution of alpha-N-acetylgalactosaminidases in marine and freshwater microorganisms]. / Rasprostranenie alpha-N-atsetilgalaktozaminidaz sredi morskikh i presnovodnykh mikroorganizmov.

The distribution of the alpha-N-acetylgalactosidases producers among 856 marine bacteria isolated from sea water, sediments and associated with sponges, mollusks, echinoderms inhabited in different area of the Pacific Ocean and 423 Baikalian microorganisms from fresh water and sponges have been studied. About 24% as marine as Baikalian strains produced this enzyme. The most number of alpha-N-Ac-galactosidase producers were found for marine bacteria genera Aeromonas, Alteromonas and Vibrio (71% and by 60%, respectively) and Baikalian microorganisms genera Aeromonas and Bacillus (40% and 31%, respectively). alpha-N-Acetyl-galactosidase was not found for marine arthrobacters, Flexibacter-Cytophaga and baikalian Micrococcus and Rhodococcus. The promising sources of the alpha-N-Ac-galactosidases were found among Alteromonas and Bacillus.