Unlocking the strength of inducible promoters in Gram-negative bacteria.

Inducible bacterial promoters are ubiquitous biotechnology tools that have a consistent architecture including two key elements: the operator region recognized by the transcriptional regulatory proteins, and the -10 and -35 consensus sequences required to recruit the sigma (σ) 70 subunits of RNA polymerase to initiate transcription. Despite their widespread use, leaky transcription in the OFF state remains a challenge. We have updated the architecture of the lac and tet promoters to improve their strength, control and portability by the adaptation of the consensus -10 and -35 sequence boxes strongly targeted by σ , incorporation of a strong ribosome binding site recognized broadly by Gram-negative bacteria, and independent control of the transcriptional regulators by constitutive promoters.

Multiple copies of the oxytetracycline gene cluster in selected Streptomyces rimosus strains can provide significantly increased titers.

Background: Natural products are a valuable source of biologically active compounds that have applications in medicine and agriculture. One disadvantage with natural products is the slow, time-consuming strain improvement regimes that are necessary to ensure sufficient quantities of target compounds for commercial production. Although great efforts have been invested in strain selection methods, many of these technologies have not been improved in decades, which might pose a serious threat to the economic and industrial viability of such important bioprocesses.

Extracellular production of the engineered thermostable protease pernisine from Aeropyrum pernix K1 in Streptomyces rimosus.

Background: The thermostable serine protease pernisine originates from the hyperthermophilic Archaeaon Aeropyrum pernix and has valuable industrial applications. Due to its properties, A. pernix cannot be cultivated in standard industrial fermentation facilities.

Screening and Heterologous Expression of a Polyethylene Terephthalate Hydrolase (PETase)-Like Enzyme (SM14est) With Polycaprolactone (PCL)-Degrading Activity, From the Marine Sponge-Derived Strain sp. SM14.

Plastics, such as the polyethylene terephthalate (PET), are widely used for various industrial applications, due to their physicochemical properties which are particularly useful in the packaging industry. However, due to improper plastic waste management and difficulties in recycling, post-consumer plastic waste has become a pressing issue for both the environment and for human health. Hence, novel technologies and methods of processing plastic waste are required to address these issues.

Corrigendum: Comparative Genomics of Marine Sponge-Derived spp. Isolates SM17 and SM18 With Their Closest Terrestrial Relatives Provides Novel Insights Into Environmental Niche Adaptations and Secondary Metabolite Biosynthesis Potential.

[This corrects the article DOI: 10.3389/fmicb.2019.

Genome Mining Coupled with OSMAC-Based Cultivation Reveal Differential Production of Surugamide A by the Marine Sponge Isolate sp. SM17 When Compared to Its Terrestrial Relative J1074.

Much recent interest has arisen in investigating isolates derived from the marine environment in the search for new bioactive compounds, particularly those found in association with marine invertebrates, such as sponges. Among these new compounds recently identified from marine isolates are the octapeptidic surugamides, which have been shown to possess anticancer and antifungal activities. By employing genome mining followed by an one strain many compounds (OSMAC)-based approach, we have identified the previously unreported capability of a marine sponge-derived isolate, namely sp.

Comparative Genomics of Marine Sponge-Derived spp. Isolates SM17 and SM18 With Their Closest Terrestrial Relatives Provides Novel Insights Into Environmental Niche Adaptations and Secondary Metabolite Biosynthesis Potential.

The emergence of antibiotic resistant microorganisms has led to an increased need for the discovery and development of novel antimicrobial compounds. Frequent rediscovery of the same natural products (NPs) continues to decrease the likelihood of the discovery of new compounds from soil bacteria. Thus, efforts have shifted toward investigating microorganisms and their secondary metabolite biosynthesis potential, from diverse niche environments, such as those isolated from marine sponges.

Production of extracellular heterologous proteins in Streptomyces rimosus, producer of the antibiotic oxytetracycline.

Among the Streptomyces species, Streptomyces lividans has often been used for the production of heterologous proteins as it can secrete target proteins directly into the culture medium. Streptomyces rimosus, on the other hand, has for long been used at an industrial scale for oxytetracycline production, and it holds 'Generally Recognised As Safe' status. There are a number of properties of S.