Complex marine natural products as potential epigenetic and production regulators of antibiotics from a marine Pseudomonas aeruginosa

Abstract

Marine microbes are capable of producing secondary metabolites for defense and competition. Factors exerting an impact on secondary metabolite production of microbial communities included bioactive natural products and co-culturing. These external influences may have practical applications such as increased yields or the generation of new metabolites from otherwise silent genes in addition to reducing or limiting the production of undesirable metabolites. In this paper, we discuss the metabolic profiles of a marine Pseudomonas aeruginosa in the presence of a number of potential chemical epigenetic regulators, adjusting carbon sources and co-culturing with other microbes to induce a competitive response. As a result of these stressors certain groups of antibiotics or antimalarial agents were increased most notably when treating P. aeruginosa with sceptrin and co-culturing with another Pseudomonas sp. An interesting cross-talking event between these two Pseudomonas species when cultured together and exposed to sceptrin was observed.

Fig. 1

Structures of antibiotics isolated from P. aeruginosa

Fig. 2

Antimicrobial activities of YPD1C extracts with different treatments *: P<0.05; **: P<0.01 as the results of Dunnett's test.

Fig. 3

Antimalarial activity of YPD1C extracts with different treatments ND: IC₅₀ was not tested due to less than 10% of inhibition in the primary assay *: P<0.05; **: P<0.01 as the results of Dunnett's test.

Fig. 4

TIC comparison of T7–T9

Fig. 5

TIC comparison of T1, T5–T6

Fig. 6

Quinolones EIC comparison of T1, T5–T6

Fig. 7

Rhamnolipids EIC comparison of T1, T5–T6