Two novel autoregulators affecting the cyto-differentiation of anthracycline-producing Streptomyces griseus have been isolated from cultures of aerial mycelium-forming progenitor strains and blocked mutants. By spectral (IR, CD, MS, 1H and 13C NMR) methods, the autoregulators are shown to be the diastereomers of 4,5-dihydroxydecanoic acid-4-lactone.
Es wird die Synthese von ω‐[Benzimidazolyl‐(2)]‐propion‐ bzw. ‐buttersäuren beschrieben, die in 5‐Stellung durch eine Stickstofflostgruppe und in 1‐Stellung durch eine Methyl‐, Äthyl‐ oder Phenylgruppe substituiert sind.
The t ur i myc in-p rod uc ing Strep tomy ces hygroscop icus strain J A 6 5 99/ N G 60-9 3 (Tur + Amy+) and strain CC1, which is unable to produce antibiotic and aerial mycelium (Tur-Amy-), were compared with respect to their mycelial enzyme activities and cellular lipid composition. Changed activities of six enzymes of intermediary metabolism during submerged growth of strain CC1 on chemically defined medium attest to alterations of the life cycle. In addition, strain CC1 contained decreased amounts of 12-methyltetradecanoic acid in relation to 14-methylpentadecanoic acid (isopalmitic acid) and displayed a quantitatively altered phospholipid composition.
Five non-streptomycin-producing non-aerial-mycelium-forming mutants (Str-Amy-) of Streptomyces griseus obtained either by spontaneous degenerat,ion or during continuous cultivation of the high-producing aerial-mycelium-forming parent strain HP (Str+Amy+) were checked with regard to t'he composit,ion of mycelial lipid material. All the Str-Amy-derivatives differed from their ancestor strain HP by an increased ratio of 13-methyltetradecanoic acid (aCl5:O) to isopalmitic acid (iC16 :0) during growth on a chemically defined medium lacking branched-chain amino acids. This finding attests alterations in the availability of precursors for t,he biosynthesis of methyl-branched fat,tJy acids. The qualitat'ive composition of phospholipids and other polar lipids in one mutant' group was found to be similar t o the progenitor strain but, addit'ionally, both it yellow pigment and a neutral lipid component were produced in excess. A second type of mutant differed by its incapability to form ornithinolipids even under phosphate limitation. Changes of phospholipid composition were demonstrated in the course of fermentation. Formation of ornithinolipid was suppressed by a n excess of inorga,nic phosphate in the medium, while the portions of phosphatidy1et)hanolamine and cardiolipin increased strongly. Furthermore, the formation of ornithinolipids was influenced by nitrogen sources. These results suggest t)hat the composition of membrane of 8. griseus varies in dependence upon the composition of the medium and the age of the mycelium. Yreeedingly, the non-aerial-m;yceliuin-forming (Amp-) and non-streptomycin-producing (Str-) derivatives LM 1, LM 2, LM 5, LM G and LM 7 of t'he industrial streptomycin-producing st'rain HP of Streptomyces qriseiis (Str+Amy+) were reported to differ froin their genetic ancest,or by very low intra-and extracelliilar levels of the NAD(1')-glycohydrolase (GRAFE et al. 1981). This work was undert'aken in order t'o hiocheniically characterize the Str-Amy-mutants obtained b y spontaneous degeneration (LM 1, JAM 2 ) or during continuous cultivation in a glycerol-limited charnostat (KOTH et al. in preparation). These strains appeared as particularly useful niodcls for studies on t.he biochemical background of the spontaneoiis variability of streptoniycetes whose true causes still await detailed elucidation (CHATER 1979, OKANISHI 1979, POGELL 1979. HOPWOOD 1978. Therefore. the lack of KAD(P)-glycohydrolase production in Str-Amy-strains (GRAFE et ul. 1981) prompted us to investigate the composition of the niycelial lipid fraction since the production of extracelliilar enzymes of Gram-positive bact,t:ria has been shown to depend on the coinposition of the cytoplasniic membrane (RAMALEY 1979). I t was the aim of this work to obtain more inforinat'ion about the differences between the Str-Amyderivatives and their ancestor, because we suppose that the genetic alterations during degeneration of strain HP were relatively small.
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