Comparative Proteomic Analysis of saccharopolyspora spinosa SP06081 and PR2 strains reveals the differentially expressed proteins correlated with the increase of spinosad yield

Abstract

BackgroundSaccharopolyspora spinosa produces the environment-friendly biopesticide spinosad, a mixture of two polyketide-derived macrolide active ingredients called spinosyns A and D. Therefore considerable interest is in the improvement of spinosad production because of its low yield in wild-type S. spinosa. Recently, a spinosad-hyperproducing PR2 strain with stable heredity was obtained from protoplast regeneration of the wild-type S. spinosa SP06081 strain. A comparative proteomic analysis was performed on the two strains during the first rapid growth phase (RG1) in seed medium (SM) by using label-free quantitative proteomics to investigate the underlying mechanism leading to the enhancement of spinosad yield.ResultsIn total, 224 proteins from the SP06081 strain and 204 proteins from the PR2 strain were unambiguously identified by liquid chromatography-tandem mass spectrometry analysis, sharing 140 proteins. A total of 12 proteins directly related to spinosad biosynthesis were identified from the two strains in RG1. Comparative analysis of the shared proteins revealed that approximately 31% of them changed their abundance significantly and fell in all of the functional groups, such as tricarboxylic acid cycles, glycolysis, biosynthetic processes, catabolic processes, transcription, translation, oxidation and reduction. Several key enzymes involved in the synthesis of primary metabolic intermediates used as precursors for spinosad production, energy supply, polyketide chain assembly, deoxysugar methylation, and antioxidative stress were differentially expressed in the same pattern of facilitating spinosad production by the PR2 strain. Real-time reverse transcriptase polymerase chain reaction analysis revealed that four of five selected genes showed a positive correlation between changes at the translational and transcriptional expression level, which further confirmed the proteomic analysis.ConclusionsThe present study is the first comprehensive and comparative proteome analysis of S. spinosa strains. Our results highlight the differentially expressed proteins between the two S. spinosa strains and provide some clues to understand the molecular and metabolic mechanisms that could lead to the increased spinosad production yield.

Promotion of spinosad biosynthesis by chromosomal integration of the Vitreoscilla hemoglobin gene in Saccharopolyspora spinosa

“…The positive correlation between the potency against hypoxia and spinosad production was also observed during the traditional genetic improvement of the SP06081 strain. Moreover, differential proteomic analysis of S. spinosa SP06081 and the spinosad-hyperproducing PR2 strain, which was obtained from its protoplast regeneration, demonstrated that a group of proteins involved in anti-oxidant stress was significantly up-regulated in the PR2 strain [37]. For the aforementioned reasons, further investigations on the improvement of oxygen uptake properties of the SP06081 strain were conducted to promote spinosad biosynthesis.…”

Strategies for Enhancing the Yield of the Potent Insecticide Spinosad in Actinomycetes

“…The first comprehensive and comparative proteomic analysis of Sa. spinosa strains using label‐free methods was presented by Luo et al in 2011. Twelve proteins directly related to spinosad biosynthesis were identified from the wild‐type Sa.…”

“…These results provided clues that these differentially expressed proteins may contribute to the improvement of spinosad production. The Luo et al study indicated that proteomics can provide information for understanding the molecular and metabolic mechanisms that may lead to the improvement of spinosad production; furthermore, it can be used to provide information about the regulatory network in Sa. spinosa .…”

High Level of Spinosad Production in the Heterologous Host Saccharopolyspora erythraea

“…Although a great number of attempts have been made for metabolic engineering of spinosad biosynthesis, there are only a few reports concerning the regulation of the expression of the spinosad gene cluster (31)(32)(33). In fact, there is as yet no report of yield improvement through manipulation of regulatory genes.…”