Effect of L‐valine and L‐isoleucine on fatty acid composition of Streptomyces hygroscopicus and S. griseus

Abstract

The effects of L-valine and L-isoleucine on the composition of mycelial fatty acids were investigated during growth of differentiating parent strains of Streptomyces hygroscopicus and Streptomyces griseus as well as their non-differentiating derivatives (Amy-strains) on a synthetic medium. Both in the Amy+ and Amy-strains, in the presence of t-valine, the portion of the isopalmitic acid (iC16:O) increased, but the addition of L-isoleucine led to an elevated level of the 12-methyltetradecanoic acid (aC15 :O). The results suggest that the genetically determined alterations in the ratio of both fatty acids in the non-differentiating derivatives may be due to specific changes in the biosynthetic pathways of both amino acid precursors rather than due to changes of their catabolism.Lipids from streptomycetes are known to contain methyl-branched is0 and anteiso fatty acids (BATRAKOV and BERGELSON 1978) whose ratio appears to play a crucial role in the regulation of membrane-associated functions (ARIMA et al. 1973, OKAZAKI et al. 1973,1974. Alterations in the composition of fatty acids may be due not only to changes of the environment (KOVALTCHUR et aZ. 1973) but may be caused also by genetic changes. Thus, the non-differentiating derivative CCl (Amy-Tur-) of the turimycin-producing and aerial-mycelium-forming Streptomyces hygroscopicus J A -6599 NGBO-93 (Amy+Tur+) has been reported to differ from the parent strain by the reduced portion of mycelial 12-methyltetradecanoic acid (aC15: 0) during growth on a synthetic medium (GRAFE et al. 1982a). Otherwise, the ratio of the 12-methyltetradecanoic acid (aC15:O) to isopalmitic acid (iC16: 0) was elevated in the non-differentiating and non-streptomycin-producing derivatives (Amy-Str-) of Streptomyces griseus HP (Amy+Str+) as compared with their ancestor (GRAFE et d. 1982b). These results suggested that differentiation in streptoriiycetes requires as a prerequisite that the cells are capable of exactly regulating the composition of the above niycelial fatty acids even under partial nutrient limitation, e. g. in the absence of particular precursors of the fatty acids in the medium.Although both fatty acids (aC15:O and iC16:O) are known to originate from isoleucine via 2-methylbutyryl coenzyme A and, respectively, from isobutyryl coenzyme A via valine, it seemed not clear from the above publications whether the biosynthesis of the amino acid precursors or their catabolisni has been subject to genetic changes. If the degradation of both amino acids would play a major role in the regulation of fatty acid composition, it could be expected that Amy+ or Amy-strains would display a different response to feeding with L-valine and L-isoleucine. On the other hand, if changes in the biosynthesis of both amino acids would be responsible for the altered

Relationship between the fatty acid composition and the type of antibiotics produced by Streptomyces lasaliensis

“…As found by GRAFE et at. (1982b) in strains of Streptomyces hygroscopicus (a turimycin producer) and S. griseus, both differentiating (Amy') and nondifferentiating (Amy-), the relative proportion of isopalmitic acid (i-16:O) increased in the presence of valine.…”

Fatty Acid Composition of Streptomyces fulvoviolaceus 818, A Producer of Antibiotic Complex

“…The presence of positional isomers of octadecenoic acid in S. fulvoviolaceus 818 is not surpricing because similar isomers were detected in S. cinnamonensis (Rezanka et al,1984) and S. aureofaciens (Behal et al, 1969). In S. hygroscopicus JA 6595, producer of turirnycin 16:0 acid was 15.7 percent (Grafe et al, 1982), while S. virginiae contained only 10.6 percent (Rezanka et al, 1992). S. fulvoviolaceus 818 synthesizes very long chain fatty acids containing from 20 to 27 carbon atoms.…”

“…Thus, some of authors have detected the cell fatty acid composition of different species an additional taxonomical criterion (Ballio and Barcellona, 1968;Rezanka et al, 1984Rezanka et al, , 1992Brondz and Olsen, 1986;Asselineau and Asselineau, 1990). Others investigators have studied fatty acid content of strains producing antibiotics and searched the closed relationhip between fatty acid formation and secondary metabolite synthesis (Kurylowicz et al, 1971;Arima et al, 1973;Grafe et al, 1982;Vancura et al, 1987;David et al, 1992;Adamidis and Sherman, 1995;Gesheva et al, 1997;Mouslim et al, 1997). Streptomyccs fulvoviolaceus 818 produces a new antibiotic complex active aga inst Gram-positive, Gram-negative bacteria, yeast and fungi (Tewfike et al,1 994).…”

“…Some authors as Arima et al (1973), Grafe et al (1982), Vancura et al (1987) and David et al (1992) concluded that the biosynthesis of antibiotics in Streptomycetes is closely associated with permeability of cell membrane which is determined by fatty acid composition. It is known that isoand anteiso-branched fatty acids play an important role in regulation of membrane functions.…”

Isolation and characterization of bioactive secondary metabolites from selected Streptomyces strains

“…Slabo antibiotsko delovanje izokiselina je očekivano, s obzirom da je pokazano da one pomažu u preživljavanju stresa kod bakterija (Kaneda 1991). Sinteza izopalmitinske kiseline počinje od startnog gradivnog bloka izobutirila, koji je detivat valina te bi s toga egzogeno dodavanje L-Val moglo da bude način povećanja prinosa izopalmitinske kiseline (Grafe, Roth et al 1982). Takođe bi bilo značajno klonirati i sekvencirati fabH gen kod soja Streptomyces sp.…”