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1.
Further studies on the role of cell-wall-degrading enzymes in cell-wall loosening in oat coleoptiles
A fungal endo-ß-l,3-glucanase was compared with afungal exo-ß-1,3-glucanase with respect to their effectson elongation and cell-wall extensibility in oat coleoptilesegments. The exo-enzyme enhanced elongation and extensibilityof the cell wall. Its effect was not additive to the effectof indole-3-acetic acid when given together with the latter,at least during 3 hr of incubation. Endo-glucanase showed nosignificant effect on elongation and no interaction with theexo-enzyme. Auxin and exo-glucanase increased extensibilityof the cell wall. The exo-glucanase was separated by isoelectricfocusing. The two fractions which were separated and showedglucanase activity induced elongation and cell wall loosening. (Received March 16, 1970; ) 相似文献
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The activities of green cell-free extracts of spinach leavesin performing photochemical transphosphorylation, photosyntheticphosphorylation, the HILL reaction and the light-induced formationof the endogenous reducing substance (ascorbic acid) were followedin parallel during the growth process of the plant. There wasa certain parallelism between the development of the activitiesof photochemical transphosphorylation, of photo-synthetic phosphorylationand of the HILL reaction, activities being low in the earlierstage of growth, reaching a maximum just before efflorescence,and showing thereafter a more or less sharp decline. The activityin the light-induced formation of endogenous reducing substancewas undetectable for the first 35 day-period of growth, reacheda maximum about one week earlier than the other three activities,and again disappeared after 60 days of growth. (Received September 9, 1960; ) 相似文献
3.
Bakunina I. Yu. Nedashkovskaya O. I. Alekseeva S. A. Ivanova E. P. Romanenko L. A. Gorshkova N. M. Isakov V. V. Zvyagintseva T. N. Mikhailov V. V. 《Microbiology》2002,71(1):41-47
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°C. The endo-type hydrolysis of fucoidan resulted in the formation of sulfated -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. 相似文献
4.
Occurrence and diversity of mesophilic Shewanella strains isolated from the North-West Pacific Ocean 总被引:1,自引:0,他引:1
Ivanova EP Sawabe T Zhukova NV Gorshkova NM Nedashkovskaya OI Hayashi K Frolova GM Sergeev AF Pavel KG Mikhailov VV Nicolau DV 《Systematic and applied microbiology》2003,26(2):293-301
Although bacteria of the genus Shewanella belong to one of the readily cultivable groups of "Gammaproteobacteria", little is known about the occurrence and abundance of these microorganisms in the marine ecosystem. Studies revealed that of 654 isolates obtained from marine invertebrates (ophiuroid Amphiopholis kochii, sipuncula Phascolosoma japonicum, and holothurian Apostichopus japonicus, Cucumaria japonica), seawater and sediments of the North-West Pacific Ocean (i.e. the Sea of Japan and Iturup Is, Kurile Islands), 10.7% belonged to the genus Shewanella. The proportion of viable Shewanella species varied from 4% to 20% depending on the source of isolation. From the isolation study, representative strains of different phenotypes (from seventy presumptive Shewanella strains) were selected for detailed characterization using phenotypic, chemotaxonomic, and phylogenetic testing. 16S rDNA sequence-based phylogenetic analysis confirmed the results of tentative identification and placed the majority of these strains within only a few species of the genus Shewanella with 98-99% of 16S rDNA sequences identity mainly with S. japonica and S. colwelliana, suggesting that the strains studied might belong to these species. Numerically dominant strains of S. japonica were metabolically active and produced proteinases (gelatinases, caseinases), lipases, amylases, agarases, and alginases. Shewanella strains studied demonstrated weak antimicrobial and antifungal activities that might be an indication of their passive role in the colonization on living and non-living surfaces. 相似文献
5.
A. M. Urvantseva I. Yu. Bakunina O. I. Nedashkovskaya S. B. Kim T. N. Zvyagintseva 《Applied Biochemistry and Microbiology》2006,42(5):484-491
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 3909T (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. 相似文献
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7.
Olga I. Nedashkovskaya Larissa A. Balabanova Natalia V. Zhukova So-Jeong Kim Irina Y. Bakunina Sung-Keun Rhee 《Archives of microbiology》2014,196(10):745-752
A Gram-negative, aerobic, rod-shaped, motile by gliding and yellow-pigmented bacterium, designated strain 10Alg 130T, that displayed the ability to destroy polysaccharides of red and brown algae, was isolated from the red alga Ahnfeltia tobuchiensis. The phylogenetic analysis based on 16S rRNA gene sequence placed the novel strain within the genus Flavobacterium, the type genus of the family Flavobacteriaceae, the phylum Bacteroidetes, with sequence similarities of 96.2 and 95.7 % to Flavobacterium jumunjiense KCTC 23618T and Flavobacterium ponti CCUG 58402T, and 95.3–92.5 % to other recognized Flavobacterium species. The prevalent fatty acids of strain 10Alg 130T were iso-C15:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C15:0 and iso-C17:1ω9c. The polar lipid profile consisted of phosphatidylethanolamine, two unknown aminolipids and three unknown lipids. The DNA G+C content of the type strain was 34.3 mol%. The new isolate and the type strains of recognized species of the genus Flavobacterium could strongly be distinguished by a number of phenotypic characteristics. A combination of the genotypic and phenotypic data showed that the algal isolate represents a novel species of the genus Flavobacterium, for which the name Flavobacterium ahnfeltiae sp. nov. is proposed. The type strain is 10Alg 130T (=KCTC 32467T = KMM 6686T). 相似文献
8.
Background
The agriculturally important pasture grass tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh.) is an outbreeding allohexaploid, that may be more accurately described as a species complex consisting of three major (Continental, Mediterranean and rhizomatous) morphotypes. Observation of hybrid infertility in some crossing combinations between morphotypes suggests the possibility of independent origins from different diploid progenitors. This study aims to clarify the evolutionary relationships between each tall fescue morphotype through phylogenetic analysis using two low-copy nuclear genes (encoding plastid acetyl-CoA carboxylase [Acc1] and centroradialis [CEN]), the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) and the chloroplast DNA (cpDNA) genome-located matK gene. Other taxa within the closely related Lolium-Festuca species complex were also included in the study, to increase understanding of evolutionary processes in a taxonomic group characterised by multiple inter-specific hybridisation events. 相似文献9.
Melanie L Hand Noel OI Cogan Timothy I Sawbridge German C Spangenberg John W Forster 《BMC plant biology》2010,10(1):94
Background
White clover (Trifolium repens L.) is an outbreeding allotetraploid species and an important forage legume in temperate grassland agriculture. Comparison of sub-genome architecture and study of nucleotide sequence diversity within allopolyploids provides insight into evolutionary divergence mechanisms, and is also necessary for the development of whole-genome sequencing strategies. This study aimed to evaluate the degree of divergence between the O and P' sub-genomes of white clover through sequencing of BAC clones containing paired homoeoloci. The microsyntenic relationships between the genomes of white clover and the model legumes Lotus japonicus and Medicago truncatula as well as Arabidopsis thaliana were also characterised. 相似文献10.
E. V. Vorobeva I. N. Krasikova A. S. Dmitrenok P. S. Dmitrenok V. V. Isakov O. I. Nedashkovskaya T. F. Solov’eva 《Russian Journal of Bioorganic Chemistry》2006,32(5):485-491
The hydrolysis of defatted cells of the marine bacterium Chryseobacterium scophtalmum CIP 104199T with 10% acetic acid (3 h, 100°C) led to an unusual lipid A (LA) (yield 0.6%), obtained for the first time. Using chemical analysis, FAB MS, and NMR spectroscopy, it was shown to be D-glucosamine 1-phosphate acylated with (R)-3-hydroxy-15-methylhexadecanoic and (R)-3-hydroxy-13-methyltetroadecanoic acids at the C2 and C3 atoms, respectively. It is similar to the monosaccharide biosynthetic precursor of lipopolysaccharide (LPS), so-called lipid X (LX). Unlike LX, LA can be isolated by the treatment of bacteria with organic solvents only after the preliminary acidic hydrolysis of the cells, which suggests that LA might be strongly, probably chemically, linked to other components of the outer membrane. However, LPS cannot be such a component, because extraction with phenol-water or phenol-chloroform-petroleum ether mixtures in high yields (5.34% and 0.5%, respectively) leads to preparations that do not contain 3-deoxy-D-manno-oct-2-ulopyranosonic acid, 3-hydroxyalkanoic acids, or LA. 相似文献