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131.
Saxelin ML Nurmiaho-Lassila EL Meriläinen VT Forsén RI 《Applied and environmental microbiology》1986,52(4):771-777
"Viili," a fermented milk product, has a firm but viscous consistency. It is produced with traditional mesophilic mixed-strain starters, which have various stabilities in dairy practice. Thirteen morphologically different types of phages were found in 90 viili samples studied by electron microscopy. Ten of the phage types had isometric heads with long, noncontractile tails, two had elongated heads with long, noncontractile tails, and one had a unique, very long elongated head with a short tail. Further morphological differences were found in the tail size and in the presence or absence of a collar, a baseplate, and a tail fiber. To find hosts for the industrially significant phages, we examined the sensitivities of 500 bacterial isolates from starters of the viili. Seven of the phages attacked Streptococcus cremoris strains, three attacked S. lactis subsp. diacetylactis strains, and four attacked Leuconostoc cremoris strains. Some phages differed only in their host specificity. Hosts were not found for 4 of the 13 morphological types of phages. 相似文献
132.
Summary Two mutants, M36 and M39, of turimycin-producingS.
hygroscopicus JA 6599/PR1 obtained by directed selection in a chemostat displayed altered pattern of amylase and -glucosidase production as revelaed by both constitutive enzyme formation and higher enzyme levels. 相似文献
133.
Bärbel Hahn-Hägerdal Sissi Berner Kerstin Skoog 《Applied microbiology and biotechnology》1986,24(4):287-293
Summary Ethanol was produced from xylose, using the enzyme glucose isomerase (xylose isomerase) and Saccharomyces cerevisiae. The influence of aeration, pH, enzyme concentration, cell mass and the concentration of the respiratory inhibitor sodium azide on the production of ethanol and the formation of by-products was investigated. Anaerobic conditions at pH 6.0, 10 g/l enzyme, 75 g/l dry weight cell mass and 4.6 mM sodium azide were found to be optimal. Under these conditions theoretical yields of ethanol were obtained from 42 g/l xylose within 24 hours.In a fed-batch culture, 62 g/l ethanol was produced from 127 g/l xylose with a yield of 0.49 and a productivity of 1.35 g/l·h. 相似文献
134.
Max Häggblom Juha Apajalahti Mirja Salkinoja-Salonen 《Applied microbiology and biotechnology》1986,24(5):397-404
Summary A polychlorophenol degrader, Rhodococcus chlorophenolicus, was shown to metabolize five different chlorinated guaiacols, namely tetrachloroguaiacol, 3,4,6-trichloroguaiacol, 3,5,6-trichloroguaiacol, 3,5-dichloroguaiacol and 3,6-dichloroguaiacol. Seven different intermediate metabolites, each with three hydroxyl or methoxyl groups, were identified. Four of these metabolites were also dehalogenation products, three carrying one chlorine atom less than the parent compound, and one metabolite from tetrachloroguaiacol where two chlorine atoms had been removed. Tetrachloroguaiacol was shown to undergo reductive dehalogenation. Demethylation of guaiacol to catechol was observed with the dichloroguaiacols, but not with polychloroguaiacols.Abbreviations DCG
dichloroguaiacol
- TCG
trichloroguaiacol
- TeCG
tetrachloroguaiacol
- DCC
dichlorocatechol
- TCC
trichlorocatechol
- TeCC
tetrachlorocatechol
- TCP
trichlorophenol
- TeCP
tetrachlorophenol
- PCP
pentachlorophenol. An example of numeration
- 346-TCG
3,4,6-trichloroguaiacol
- GLC
gas liquid chromatography 相似文献
135.
Johann-Wolfgang Wägele 《Polar Biology》1986,6(3):145-152
Summary The spatial distribution and size-dependence of oxygen consumption (respiration) and production by microplankton in near surface waters of the Canadian Arctic were measured during summer, 1983. High oxygen flux rates (consumption and production) were observed near surface (upper 20–30 m) and were generally associated with high phytoplankton biomass (chlorophyll a) levels. A substantial portion of the respiration (>50%), however, was below the euphotic zone. Integrated oxygen fluxes (0–100 m) were approximately in balance (i.e., net oxygen production 0) at most locations sampled. In general, oxygen fluxes were higher than have been observed in the Southern Ocean but in the same range as found in temperate coastal waters. Size-fractionation studies showed that most (>60%) of the oxygen production and phytoplankton biomass (chlorophyll a) were associated with organisms greater than 35 m. On the other hand, more than 70% of the respiration was associated with organisms less than 35 m; on average, more than 50% of the respiration was associated with organisms less than 1 m. These results are consistent with theoretical studies and with experimental observations from temperate waters. 相似文献
136.
Light-temperature interactions in the control of photosynthesis in Antarctic phytoplankton 总被引:6,自引:4,他引:2
Summary During October/November 1983 photosynthetic responses of natural phytoplankton from the Scotia Sea and Bransfield strait to light and temperature were examined in incubators. Both assimilation numbers at saturating light levels and the slopes of the light-limited portions of the photosynthesis versus irradiance curves were smaller than in algae from lower latitudes. However, both parameters increased significantly with rising temperatures. Light-saturated photosynthesis on the average exhibited a Q10-value of ca. 4.2 between-1.5°C and +2°C. Light-limited photosynthesis between-1.5°C and +5°C rose at a rate corresponding to a Q10-value of roughly 2.6. Above +5°C, temperature enhancement of both light-saturated and light-limited photosynthetic rates was minimal or absent. Our results suggest that under extremely low temperatures light-limited photosynthetic rates become temperature-dependent due to changes in maximum quantum yields. 相似文献
137.
Johann-Wolfgang Wägele 《Polar Biology》1986,6(3):127-137
Summary A rich collection of Ceratoserolis trilobitoides from the Antarctic Peninsula and the western and southern Weddell Sea is evaluated to describe the polymorphism and variations of the pigmentation. The species is very variable, though local populations show a relatively homogenous morphology. Transitional forms connect different morphotypes. Presumably the relative immobility of these animals, together with low fecundity and geographical or hydrographical barriers are responsible for the evolution of local races. C. cornuta and the colour-spcies of Cals (1977) are synonymized with C. trilobitoides. 相似文献
138.
Peptide patterns and immunological properties of the cytoplasmic and chloroplastic -1,4-glucan phosphorylase (EC 2.4.1.1) from spinach leaves have been studied and were compared with those of phosphorylases from other sources. The two spinach leaf phosphorylases were immunologically different; a limited cross-reactivity was observed only at high antigen or antibody concentrations. Peptide mapping of the two enzymes resulted in complex patterns composed of more than 20 fragments; but no peptide was electrophoretically identical in both proteins. Approximately 13 to 15 of the fragments exhibited antigeneity but no cross-reactivity of any peptide was observed. Therefore, the two compartment-specific phosphorylase forms from spinach leaves represent isoenzymes possessing different primary structures. Peptide patterns of potato tuber and rabbit muscle phosphorylase were different from those of the two spinach leaf enzymes. Although the potato tuber phosphorylase resides in the plastidic compartment and is kinetically closely related to the chloroplastic spinach enzyme, it reacted more strongly with the anti-cytoplasmic-phosphorylase immunoglobulin G. Similar results were obtained with rabbit muscle phosphorylase. These observations support the assumption that the chloroplast-specific phosphorylase isoenzyme has a higher structural diversity than does the cytoplasmic counterpart.Abbreviations EDTA
ethylenediaminetetraacetic acid
- Hepes
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- PEG
polyethylene glycol (approx. MW 8000)
I=Schächtele and Steup 1986 相似文献
139.
We have analysed the intracellular localisation of phytochrome in oat coleoptile cells by electron microscopy and confirm and extend light-microscopical findings of previous authors. We used indirect immuno-labeling with polyclonal antibodies against 60-KDa phytochrome from etiolated oat seedlings, and a gold-coupled second antibody, on ultrathin sections of LR-white-embedded material. In dark-grown seedlings, phytochrome-labeling is distributed diffusely throughout the cytoplasm. Organelles and membranes are not labeled. After photoconversion of the red-absorbing form of phytochrome to the far-red absorbing form (Pfr) (5-min red light; 660 nm), the label is sequestered uniquely in electron-dense areas within the cytoplasm. These areas are irregularly shaped, are often located in the vicinity of the vacuole, are not surrounded by a membrane, exclude cellular organelles and ribosomes and are not found in dark-grown material; an immediate 5-min farred light pulse after the red light does not cause these structures to disappear. After a dark period of 3–4 h following red-light irradiation, these electron-dense structures disappear together with any specific labeling. We suggest a Pfr-induced aggregation of an unknown, phytochrome-binding protein or proteins.Abbreviations
Pr and Pfr
phytochrome in its red and far-red absorbing form, respectively 相似文献
140.
The cell wall of Cobaea scandens seed hairs developed in a characteristic sequence, with the deposition of a cellulose thread onto a pectic swelling layer was the final event. The cellulose thread was intracellularly accompanied by a band of 10–18 microtubules. During the formation of the swelling layer the microtubules were homogeneously distributed; they ran circumferentially normal to the cell axis. When cellulose-thread formation started, the microtubules became arranged in a helical band. The density of the microtubules varied during the different phases of development. The highest density was observed before cellulosethread formation and ranged from 6–15 m·m-2. The length of the microtubules, 20–30 m, was determined by direct measurements, as well as estimated from the total microtubular length in a given area and the counted free ends. With the indirect immunofluorescence technique the microtubules of the band stained inhomogeneously. Those which were located at the edges of the band fluoresced more intensely than those of the central part. Attempts to visualize actin filaments in the hair cells with rhodaminyl-conjugated phalloidin resulted in a homogeneous staining of the area of the microtubular band, indicating that actin filaments may be present in this region. Though, in thin sections and dry-cleaved cells, filamentous structures were observed between the microtubules, caution is expressed that the observed fluorescence was, indeed, due to actin filaments. The role of the filamentous structures is discussed with respect to formation and maintenance of the microtubular band. Microtubules apparently did not cross coated pits which were visualized in the plasma membrane through the dry-cleaving technique.Abbreviations IFT
indirect immunofluorescence technique
- RP
rhodaminyl-conjugated phalloidin
- SEM
scanning electron microscopy 相似文献