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81.
Cellulose- and xylan-degrading enzymes of Trichoderma reesei QM 9414 induced by, sophorose, xylobiose, cellulose and xylan were analyzed by isoelectric focusing. The sophorose-induced enzyme system contained two types of endo-1,4--glucanases (EC 3.2.1.4), one specific for cellulose and the other non-specific, hydrolyzing both cellulose and xylan, and exo-1,4--glucanases (cellobiohydrolases I, EC 3.2.1.91), i.e. all types of glucanases that are produced during growth on cellulose. Specific endo-1,4--xylanases (EC 3.2.1.8) present in the cellulose-containing medium were less abundant in the sophorose-induced enzyme system. Xylobiose and xylan induced only specific endo-1,4--xylanases. It is concluded that syntheses of cellulases and -xylanases in T. reesei QM 9414 are under separate control and that the non-specific endo-1,4--glucanases are constituents of the cellulose-degrading enzyme system. 相似文献
82.
Incomplete ischemia of the spinal cord was produced in dogs by 40 min occlusion of the abdominal aorta that was followed by 5–40 min of recirculation. Amino acid incorporation into ribosomes in vitro in the presence of venous blood sera was estimated. The most significant reduction in incorporation was produced by sera of the dogs following a short recirculation period (5–10 min). No significant changes were observed at the end of the ischemic period nor at longer periods of recirculation. The decrease in incorporation might be the consequence of inactivation or absence of a substance stimulating polypeptide synthesis in vitro, normally present in blood sera of intact dogs, that temporarily loses its activity during recirculation. 相似文献
83.
Agrobacterium radiobacter, strain B6 (a strain isolated in this laboratory, which limited the occurrence of damping-off of sugar beet and influenced growth of plants in hot-house and field experiments) was found to produce an acidic exopolysaccharide in a mineral medium with various carbon sources. Hydrolyzates of the polysaccharide contained glucose, galactose, glycerol, succinic acid and pyruvic acid, whose quantitative content varied according to the carbon source used. The polysaccharide isolated from the medium containing glucose exhibited the highest physiological activity. Seeds germinated best and sugar beet roots were found to grow most rapidly in a medium containing 0.2 % (W/W) of the polysaccharide. The roots exposed for 3 d in this medium grew 2.7-fold as compared with non-treated plants. Higher sumbers of microorganisms were detected on the surface of roots treated with the polysaccharide. Growth of roots was also stimulated when immersing the seeds (30 min) in a 0.2 –0.4 % solution of this polysaccharide. After a two-fold treatment the roots were less damaged by the fungusPythium ultimum. Plants from seeds treated with the polysaccharide grew in the field soil more rapidly than the non-treated plants but worse than after bacterization of the seeds byA. radiobacter B6 and were only partially protected against the damping-off of sugar beet. 相似文献
84.
Labuctril 25 (3,5-dibromo-4-hydroxybenzonitrile, LAB) at concentrations up to 100μg/mL inhibits effectively growth, morphology, and pigmentation of most soil streptomycete isolates grown under laboratory conditions. Oxytril CM (OXT), Basagran (BAS) and Faneron 50 WP (FAN) applied at the same concentrations had no detectable effect on growth of substrate mycelium but suppressed both aerial mycelium and pigment formation, the effectivity decreasing in the order OXT—BAS—FAN. The LAB-sensitivity of mutant strains was markedly higher as compared with that of the soil isolates. A wild strain resistant to 100–400μg of LAB per mL (depending on the medium composition) was isolated. It was capable of supporting the growth and development of sensitive strains on the LAB-containing medium. A stimulatory effect of low doses of LAB (10–20μg/mL) on the antibiotic activity of streptomycetes was observed. 相似文献
85.
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Jana Pospíšilová Jiřina Slavíkovà J. Tupý Ingrid Tiohá T. Gichner 《Biologia Plantarum》1983,25(3):237-240
88.
Preferential association of kappa IIIb light chains with monoclonal human IgM kappa autoantibodies 总被引:21,自引:0,他引:21
D K Ledford F Go?i M Pizzolato E C Franklin A Solomon B Frangione 《Journal of immunology (Baltimore, Md. : 1950)》1983,131(3):1322-1325
The predominance of the relatively uncommon V region subgroup isotype kappa III among the light chains of human monoclonal (IgM kappa) anti-IgG antibodies, (i.e., rheumatoid factors), was further documented through sequence analyses of ten such autoantibodies isolated from IgM-anti-IgG cold-insoluble immune complexes (mixed cryoglobulins). The amino-terminal sequence of all ten kappa-chains was characteristic for kappa III proteins and virtually identical to that of a prototype kappa III light chain. Similar sequence identity was found for kappa-chains isolated from three IgM kappa autoantibodies that formed cold-insoluble immune complexes with low-density lipoprotein (LDL). The thirteen light chains were found to be virtually identical in sequence for the first framework region (FR); ten of these proteins sequenced through the first complementarity-determining region (CDR) and into the second FR were markedly similar. The second CDR of five proteins was almost identical in sequence to that of the prototype kappa III-chain. Concordance was also demonstrated between the structural classification of the light chains as kappa III and their immunochemical classification as members of this V region subgroup. Serologic analyses of light chains isolated from seven IgM kappa autoantibodies (six anti-IgG, one anti-LDL) and of one intact IgM kappa anti-LDL antibody showed that each had antigenic determinants common to kappa II proteins. These light chains also expressed the antigenic determinant(s) of a V-region sub-subgroup of kappa III proteins designated kappa IIIb. Our studies confirm the preferential association of kappa III (and kappa IIIb) light chains with IgM kappa anti-IgG antibodies and demonstrate a similar association for IgM kappa anti-LDL antibodies. The finding that these and other types of IgM kappa autoantibodies, e.g., cold agglutinins, have remarkably similar light chains suggests an inherent restriction in the immune response to self-antigens. 相似文献
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90.