Biochemical characteristic of non‐streptomycin‐producing mutants of Streptomyces griseus. II. Lipids and fatty acid composition of vegetative mycelia

Abstract

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.

Maintenance of the recombinant plasmid pIJ2 in chemostat cultures of Streptomyces lividans 66 (pIJ2)

“…Although different culture conditions were used clones altered in differentiation as observed in investigations under similar conditions with S. hygroscopicus , ROTH et al 1982a, GRXFE et aZ. 1982a) and S. griseus (ROTH et al 1982b, GRXFE et al 1981, 1982b) did not appear. All colonies growing from mycelium withdrawn from the continuous cultures formed aerial mycelium and spores as well as the red pigment.…”

“…Beside the neomycin resistance we monitored the stability of S. liuidans 66-PM1 with respect to aerial mycelium and pigment formation in the course of the experiments. Although different culture conditions were used clones altered in differentiation as observed in investigations under similar conditions with S. hygroscopicus , ROTH et al 1982a, GRXFE et aZ. 1982a) and S. griseus (ROTH et al 1982b, GRXFE et al 1981, 1982b) did not appear.…”

The transglutaminase activating metalloprotease inhibitor from Streptomyces mobaraensis is a glutamine and lysine donor substrate of the intrinsic transglutaminase

“…In this context, it may be of some interest that actinomycetes form lipoamino acids, when essential phosphates are exhausted [26,27]. During bacterial life, phosphate deficiency may trigger sporulation [28], suggesting, formation of LS‐like surfactants could induce or, at least, support TGase cross‐linking in the cell wall of aerial mycelium.…”

Effect of the autoregulator from Streptomyces griseus JA 5142 on surface cultures of blocked mutant ZIMET 43682

“…When the autoregulator was present in cultures of Table 1 Mycelial fatty acids from surface cultures of S. griseus JA 5142 (P: parental strain), blocked mutant ZIMET 43682 (C: control) and ZIMET 43682 + autoregulator (F: factor added). Abbreviations: i14:1, 12-methyltridecanoic acid; 14:O. tetradecanoic acid; a15:0, 12-methyltetradecanoic acid; i16:0, isopalmitic acid; 16:0, palmitic acid; 16: 1, palmitoleic acid; a17 :0, 14-methylhexadecanoic acid; 18:0, stearic acid (GRAFE et al 1982b) suggesting that alterations of membrane structure and function may take place during the cell cycle of streptoniycetes. But from the differences found in cytochrome spectra and lipid coniposition of mutant ZIMET 43682 after addition of autoregulator it should not be concluded that this endogenous effector initially interferes with cellular systems accomplishing the synthesis of components of the cytoplasmic membrane.…”