摘要:

AbstractThe present study focuses on the effects of different kinds of visible light, the intensities of white light, temperature and pH on akinete germination in the green algaPithophora oedogonia(Mont.) Wittrock. In addition, it was studied how different kinds of visible light applied during akinete formation influenced the subsequent germination in white light. Akinetes initiated to germinate 3 days earlier in blue and green light than in yellow, red and white light. The green light was most favourable to akinete germination, while red light had a poor effect. No photoreversible effect of red and green light was observed. Akinetes formed under green, blue and yellow light germinated quickly and showed a higher percentage of germination than those formed under red light. Germination of akinetes was initiated even when kept in total darkness. Germination of akinetes was favoured in white light at intensities between 0.50 and 1.5 Klux. Maximum germination of akinetes occurred at 25 °C, while progressively higher and lower temperature suppressed germination of akinetes at different levels. Initiation of akinete germination was delayed at a pH of 7 and 8. No germination of akinetes was observed at a pH of 9 and 10

ISSN:0233-111X    

DOI:10.1002/jobm.3620260402

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620260404

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

摘要:

AbstractThe monosaccharide composition of the LPS from 5Campylobacter jejunistrains and 7Campylobacter colistrains has been studied. All LPS's contained KDO, heptose, glucosamine, glucose, and (with one exception) galactose. AllC. jejuniand 3C. coliLPS contained>1% galactosamine. 3‐Amino‐3.6‐dideoxyglucose was present in all but oneC. coliLPS and in only oneC. jeju

ISSN:0233-111X    

DOI:10.1002/jobm.3620260405

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

摘要:

AbstractBalance equations for some representatives of the main biogenetic groups of secondary metabolites were formulated which provide the known and probable reactions within the biosynthetic routes. The calculated yieldsYmaxp/swith respect to the usual substrate glucose range between 0.37 and 0.9 and, obviously, they agree well with the theoretical yields of biochemically related parts of cell dry mass. The sugar derivatives correspond to carbohydrates, the β‐lactams and shikimate derivatives to proteins, and finally, the polyketides and mevalonate derivatives to lipids. From this stoichiometric point of view the secondary metabolism thus seems to possess the same biosynthetic efficiency as adequate parts of primary metabolism under the conditions of retarded growth.The introduction of theYmaxp/svalues into an equation for substrate consumption regarding the growth, maintenance and product formation (van der Beek and Roels 1984) delivered yields which demonstrated that more than 70% of the glucose flowed into byproducts or waste metabolites, respective

ISSN:0233-111X    

DOI:10.1002/jobm.3620260406

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620260407

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

摘要:

AbstractMembrane‐attached nucleoids were isolated fromE. coliand separated from proteins by 2 m NaCl. Desintegration of such nucleoids by ultrasound and subsequent centrifugation resulted in the formation of two fractions: a sediment (fraction I) and a supernatant (fraction II). The protein:DNA ratio of fraction I was equal to 27 and was different from that to fraction II (2.6). More than 70% of the proteins not dissociating at 2 m NaCl and bound to DNA of both fractions were polypeptides with molecular weights (Mw) of 31,000–23,000 daltons (31–23 Kdal).After pulse labelling of the cells with [3H]‐thymidine, the specific radioactivity of newly synthesized DNA associated with fraction I was shown to be considerably higher than that of fraction II. The analysis of DNA‐synthesizing activities in fractions I and II showed that both nucleoid fractions contained DNA polymerase I.After dissolving the two fractions in 8 m urea – 0.15% sodium dodecylsulphate (SDS) they were chromatographed on hydroxyapatite. DNA‐protein complexes were obtained that did not dissociate at 4 m guanidine. HCI – 5 m urea and 1% SDS. The main protein of the complexes was a 31 Kdal polypeptide tight

ISSN:0233-111X    

DOI:10.1002/jobm.3620260408

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

摘要:

AbstractDuring exponential growth mycelia ofStreptomyces granaticolor and Streptomyces hygroscopicuswere pulse‐labelled with3H‐thymidine for different times. The distribution of silver grains was analyzed in the autoradiograms by using the unit cell‐concept, according to which a unit cell corresponds to the hyphal length containing one nucleoid, i. e. one genome equivalent.All nucleoids of the mycelia were labelled, if the pulse extended for more than 50% of the doubling time. Thus, in young mycelia there were no nucleoids in which had stopped replication at all. However, the mycelia showed an increasing fraction of non‐replicating nucleoids, if the pulse was shortened. This fact indicated that nucleoids transiently lacked replication.The fraction of non‐replicating nucleoids as determined from the latter samples allowed to calculate the replication timeCof the individual nucleoids. TheCperiod occupied about 54% of the doubling time in mycelia growing with a generation time of 96 to 415 min.Replication of neighboured nucleoids was not sy

ISSN:0233-111X    

DOI:10.1002/jobm.3620260409

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620260410

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

摘要:

AbstractTwo mutants ofNocardia restrictabreakdown androst‐4‐ene‐3,17‐dione into 3aα‐H‐4α‐(3′‐propionic acid)‐5α‐hydroxy‐7aβ‐methylhexahydro‐l‐indanone‐δ‐lactone. The metabolic intermediates formed are very different in each mutant. One uses certain aromatic compounds very slowly. A degradation pathway for steroids

ISSN:0233-111X    

DOI:10.1002/jobm.3620260411

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY

摘要:

AbstractA nourscothricin‐producingStreptomyces nourseistrain was continuously cultivated in a chemostat equipped with a stirrer for mechanical fractionation of the mycelium. Different cultivation conditions allowed the selection of six types of differentiation mutants after the culture had reached a population genetically stationary state. The mutants showed an altered control pattern of sporulation as well as altered antibiotic biosynthesis and antibiotic resistance. In addition, the stability of the recombinant plasmid pIJ385 in several differentiation type mutants as host strains was tested. The results suggest that there exists a strong correlation between the cultivation conditions employed and the type of differentiation mutants selecte

ISSN:0233-111X    

DOI:10.1002/jobm.3620260412

出版商:Wiley‐VCH    

年代:1986

数据来源: WILEY