摘要:

AbstractThe effect of the photosynthesis‐inhibiting herbicides Goltix, Sencor, Tycor, Arelon, DCMU, paraquat and atrazine on growth and nitrogenase activity of a new isolate of cyanobacteria,NostocG3 was studied.NostocG 3 was cultivated underN2‐fixing photoautotrophic conditions. The used herbicide concentrations were in the range or recommended field rates. In the presence of Goltix (50 mg/l and 100mg/l), Arelon (15 mg/l und 30 mg/l), paraquat (10 mg/l and 20 mg/l) and DCMU (1 μM) the growth and nitrogenase activity ofNostocG3 was almost completely inhibited. The most severe inhibitory effect was observed in the presence of paraquat. Even 1 h treatment of 1 mg/l paraquat caused a total inhibition of growth for 4 weeks. In contrast, the herbicides Sencor (10 mg/l and 20 mg/l) and Tycor (10 mg/l and 50 mg/l) did not cause inhibition of growth and nitrogenase activity. In the presence of atrazine (1 mg/l and 2 mg/l) the nitrogenase activity and the growth were partially inhibited. The results obtained in this study show that cyanobacteria occurring in natural environments are resistant against some of the photosynthesis‐inhibiting herb

ISSN:0233-111X    

DOI:10.1002/jobm.3620280702

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractFour strains ofStreptococcus pyogeneswere propagated at 37 °C in a reduced iron medium supplemented with Fe3+‐citrate to give concentrations of 1 through 11 micrograms per milliliter, in order to observe the effects of iron on growth and on thevitroproduction of Streptolysin S. Both growth and hemolysin production were observed to be influenced by medium iron concentration of which 1.2 μg per ml of iron was critical. Hemolysin was produced during the exponential phase of the growth cycle with maximum yield as the organism entered the stationary phase. Hemolytic activity (which was accepted as the ability of the hemolysin to lyse sheep erythrocytes) fell below detectable levels as the organisms entered fully into the stationary phase (9–10 hours post incubation). Serum (bovine, human, chicken) was observed to have a high stabilizing effect on the hemo

ISSN:0233-111X    

DOI:10.1002/jobm.3620280703

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe group specific polysaccharide of Group B streptococci was isolated either by means of phenol‐water extraction or by Lancefield extraction procedures. Two groups of rabbits were immunized with these substances to induce polyclonal antibodies. The phenol‐water extract induced antisera had a significantly higher titer against B streptococci than against A‐, D‐ and G streptococci in the agglutination reaction. The B‐specific titers in rabbits immunized with phenol‐water extract were significantly higher than those obtained in the rabbits immunized with Lancefield extract.In counter immunoelectrophoresis, only the antisera prepared by immunization with phenol‐water extract reacted with standard antigen from group B streptococci. The serological specificity of the phenolwater extract antigen isolated from B streptococci was confirmed by counterimmunoelectrophoresis. The antigen was a heterologous fraction with a molecular mass of 8 × 104

ISSN:0233-111X    

DOI:10.1002/jobm.3620280704

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe recombinant symbiotic (Sym) plasmids pIJ1008 and pIJ1019 and the natural Sym plasmid pJB5JI ofRhizobium leguminosarumwere transferred to derivatives of theRhizobium melilotistrain Rm41 and to local wild strains ofR. melilotito investigate their transfer frequency and stability. Transfer to the latter strains was only successful through two‐step conjugations, i.e. transfer to a compatibleR. melilotistrain followed by transfer to wild strains. The transferred Sym plasmids and the resident plasmids ofR. melilotiwith a molecular weight up to approximately 300 Md showed instability, resulting in the elimination of the latter, whereas theR. melilotimegaplasmids and their symbiotic properties were maintained. The natural plasmid pJB5JI was stable in free living transconjugants as well as those in symbiosis with alfalfa or pea. The two recombinant Sym plasmids showed deletions or structural changes dependending on the genotype of the recipient and the transferred plasmids. During symbiosis these plasmids may be further deleted or completely eliminated. The consequences for gene transfer programs are discussed in the pape

ISSN:0233-111X    

DOI:10.1002/jobm.3620280705

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280707

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractWhole cell immobilization ofLactobacillussp. cells forD‐glucose isomerase activity was done by taking well washed cell slurries of bacteria, coating them on rough surfaces of glass rods or glass slides, drying them at 50 °C to 55 °C under infra red lamp and finaly treating with polyvinyl alcohol. The immobilized glucose isomerase activity of cells showed remarkable change in pH optimum, thermal stability,KmandVmaxvalues as compared to free enzyme of cells. The immobilized enzyme system was employed in the conversion of glucose to fructose using concentrates of amylase‐treated corn starch and cellulase‐treated bagasse ce

ISSN:0233-111X    

DOI:10.1002/jobm.3620280708

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280710

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe effects of monovalent and divalent cations on the cell viability of an extremely halophilic bacteriaH. mediterraneiwere examined. High magnesium concentrations (≧72 mM) were required for stabilization ofH. mediterraneicells, although calcium ions were more potent than magnesium in preserving viability. On the other hand,H. mediterraneicells are also able to survive in the presence of monovalent cations, such as ammonium and potassium, at least 14 days. The implications for maintaining stability and neutrality of several cell envelope components by monovalent and divalent cations are discusse

ISSN:0233-111X    

DOI:10.1002/jobm.3620280711

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280713

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractA survey of the pSM10 family of streptococcal plasmid cloning vectors is provided. These vectors are derived from a macrolide‐lincosamide‐streptograminBresistance plasmid and include general cloning vectors, shuttle vectors, helper plasmids, expression vectors, gene fusion vectors and phasmids. Besides describing their general properties, this paper also provides their genetic and physical m

ISSN:0233-111X    

DOI:10.1002/jobm.3620280714

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY