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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1983-2-25
pubmed:abstractText
The spontaneous mutant 18a derived from Streptomyces kasugaensis MB273 exhibited pleiotropic effect such as loss of aerial mycelium formation, aureothricin (AT) production, and of citrullin biosynthesis, as well as changes in plasmid; the mutant required cystine for production of aureothricin. An improved method of protoplast regeneration was applied to S. kasugaensis MB 273-18a and a regeneration efficiency of 90% or more was obtained. Sixty to ninety percent of the colonies regenerated from the 18a protoplasts exhibited reversion of the pleiotropic mutation in 18a. Moreover, of 13 regenerated strains which showed these drastic phenotypic variations, it was found that their plasmid types varied. These types could be divided into two groups; the RI type (5 strains) which contained a large amount of pSK2, a small amount of pSK3 and no pSK1, and the RII type (8 strains) in which no closed-circular DNA was detected. From these results, the following conclusions were obtained. First, plasmid curing in RII type strains and also the variation of plasmid copy in the RI type strains occurred as the result of protoplast regeneration. Second, the structural genes for biosynthesis of AT probably exist on chromosome. Third, regeneration of 18a protoplasts causes the reversion of pleiotropic mutation with high frequency. A working hypothesis was proposed to explain these complex phenomena.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-8820
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1367-73
pubmed:dateRevised
2006-5-1
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Function of plasmids in the production of aureothricin. I. Elimination of plasmids and alteration of phenotypes caused by protoplast regeneration in Streptomyces kasugaensis.
pubmed:publicationType
Journal Article