Heterologous expression of oxytetracycline biosynthetic gene cluster in Streptomyces venezuelae WVR2006 to improve production level and to alter fermentation process

Abstract

Heterologous expression is an important strategy to activate biosynthetic gene clusters of secondary metabolites. Here, it is employed to activate and manipulate the oxytetracycline (OTC) gene cluster and to alter OTC fermentation process. To achieve these goals, a fast-growing heterologous host Streptomyces venezuelae WVR2006 was rationally selected among several potential hosts. It shows rapid and dispersed growth and intrinsic high resistance to OTC. By manipulating the expression of two cluster-situated regulators (CSR) OtcR and OtrR and precursor supply, the OTC production level was significantly increased in this heterologous host from 75 to 431 mg/l only in 48 h, a level comparable to the native producer Streptomyces rimosus M4018 in 8 days. This work shows that S. venezuelae WVR2006 is a promising chassis for the production of secondary metabolites, and the engineered heterologous OTC producer has the potential to completely alter the fermentation process of OTC production.

Streptomycetes: Surrogate hosts for the genetic manipulation of biosynthetic gene clusters and production of natural products

“…The production of oxytetracycline (oct) was increased from 75 to 431 mg/L in only 48 h by the expression of two pathway-specific regulators OctR and OtrR along with precursor supply in S. venezuelae WVR2006, a level comparable to 8 days in its native producer S. rimosus M4018. (Yin et al, 2016). The 40-kb DNA region containing five PKS genes from the tylosin pathway was cloned under the control of the strong ermE* promoter in two plasmids and introduced into S. venezuelae DHS2001, which led to the production of about 0.5 mg/L of the 16-membered tylactone and 5- O -mycaminosyl tylactone (Figure 6A) (Jung et al, 2007).…”

Leveraging synthetic biology for producing bioactive polyketides and non-ribosomal peptides in bacterial heterologous hosts

“…132 Oxytetracycline is a precursor for the semi-synthesis of tetracycline-based antibiotics. 133 Tetracycline and its derivatives interfere with the association of aminoacyl-tRNAs with the ribosome in bacteria thereby inhibiting protein synthesis. 134 The BGCs producing neoantimycins from Streptomyces conglobatus and Streptomyces orinoci were recently characterized through heterologous expression of the clusters in S. albus.…”

Identification and Antimicrobial Properties of Malaysian Mangrove Actinomycetes

“…The antimicrobial production from marine-derived actinomycetes has been reported by [15], [16], [18]. In addition, bioactive compounds act as antibacterial and antifungal from marine actinomycetes have been elucidated, such as erythromycin [35] isolated from Saccharopolyspora erythrae, oxytetracycline [36] obtained from Streptomyces rimosus, rapamycin [37] as antifungal from Streptomyces hygroscopicus and many more. Among actinomycetes, Streptomyces are known as the most valuable genera in producing active compounds [38] and recently there has been increasing number of novel metabolites possessing potent bioactivity isolated from marine-derived Streptomyces [39], [40].…”