Effect of branched-chain amino acids, valine, isoleucine and leucine on the biosythesis of bitespiramycin 4"-O-acylspiramycins

Abstract

Bitespiramycin, a group of 4"-O-acylated spiramycins with 4"-O-isovalerylspiramycins as the major components, was produced by recombinant spiramycin-producing strain Streptomyces spiramyceticus harboring a 4"-O-acyltransferase gene. The experiment was initially performed in synthetic medium with 0.5 g l-1 Valine, Isoleucine or Leucine feeding at 36 h cultivation. When valine was fed, the biological titer of bitespiramycin was 45.3% higher than that of the control group, but the relative content of total isovalerylspiramycin components decreased by 22.5%. In the case of ilecine, the biological titer of bitespiramycin and the total isovalerylspiramycins alone were 85% and 72.1% of the control group, respectively. In contrast, the relative content of other acylated spiramycins increased by 54.41%. However, leucine feeding increased the relative content of total isovalerylspiramycins by 41.9% while the biological titer of bitespiramycin was nearly equal to that of the control group. The improvement effect of leucine on the biosynthesis of isovalerylspiramycins was further confirmed by feeding of 2.0 g l-1 leucine to the culture with complex medium. After batch feeding with a total amount of 2.0 g l-1 leucine to the culture from 70 h to 90 h, the biological titer of bitespiramycin was almost unreduced, and the final relative content of total isovalerylspiramycins increased from 31.1% to 46.9%.

Cowpea NAC Transcription Factors Positively Regulate Cellular Stress Response and Balance Energy Metabolism in Yeast via Reprogramming of Biosynthetic Pathways

“…Phosphoserine, an intermediate in serine and cysteine biosynthesis, branched amino acids such as threonine and isoleucine, which also aid in the fermentation process, were piled up. 47 Further, we found a significant accumulation of methionine and sulfate ions, a marker for amino acid sufficiency. 48 This explained the prolongation of the logarithmic phase of transgenic strains, probably via inhibition of autophagy signaling.…”

“…Glycine, the starting ingredient of thiamine and other amino acids, seemed to be exhausted. Phosphoserine, an intermediate in serine and cysteine biosynthesis, branched amino acids such as threonine and isoleucine, which also aid in the fermentation process, were piled up . Further, we found a significant accumulation of methionine and sulfate ions, a marker for amino acid sufficiency .…”

Quorum sensing activity in Ophiostoma ulmi: effects of fusel oils and branched chain amino acids on yeast-mycelial dimorphism

“…Our study also revealed the effect of branched‐chain amino acids on the morphology of O. ulmi (Table 2), possibly associated with their acting as precursors for fusel alcohols, fusel acids or other similar secondary metabolites. Furthermore, some amino acids such as valine (Val), isoleucine (Ile) or leucine (Leu) are precursors for other secondary metabolites (Li et al. 2009).…”