Microparticles enhance the formation of seven major classes of natural products in native and metabolically engineered actinobacteria through accelerated morphological development

Abstract

Actinobacteria provide a rich spectrum of bioactive natural products and therefore display an invaluable source towards commercially valuable pharmaceuticals and agrochemicals. Here, we studied the use of inorganic talc microparticles (hydrous magnesium silicate, 3MgO•4SiO 2 •H 2 O, 10 µm) as a general supplement to enhance natural product formation in this important class of bacteria. Added to cultures of recombinant Streptomyces lividans, talc enhanced production of the macrocyclic peptide antibiotic bottromycin A2 and its methylated derivative Met-bottromycin A2 up to 109 mg L −1 , the highest titer reported so far. Hereby, the microparticles fundamentally affected metabolism. With 10 g L −1 talc, S. lividans grew to 40% smaller pellets and, using RNA sequencing, revealed accelerated morphogenesis and aging, indicated by early upregulation of developmental regulator genes such as ssgA, ssgB, wblA, sigN, and bldN. Furthermore, the microparticles re-balanced the expression of individual bottromycin cluster genes, resulting in a higher macrocyclization efficiency at the level of BotAH and correspondingly lower levels of noncyclized shunt by-products, driving the production of mature bottromycin. Testing a variety of Streptomyces species, talc addition resulted in up to 13-fold higher titers for the RiPPs bottromycin and cinnamycin, the alkaloid undecylprodigiosin, the polyketide pamamycin, the tetracycline-type oxytetracycline, and the anthramycinanalogs usabamycins. Moreover, talc addition boosted production in other actinobacteria, outside of the genus of Streptomyces: vancomycin (Amycolatopsis japonicum DSM 44213), teicoplanin (Actinoplanes teichomyceticus ATCC 31121), and the angucyclinone-type antibiotic simocyclinone (Kitasatospora sp.). For teicoplanin, the microparticles were even crucial to activate production. Taken together, the use of talc was beneficial in 75% of all tested cases and optimized natural and heterologous hosts forming the substance of interest with clusters under native and This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Co-cultivation of filamentous microorganisms in the presence of aluminum oxide microparticles

“…6b ). It should be noted that Kuhl et al ( 2021 ) applied a different medium, a different type of microparticles (talc), and, finally, cultivated S. rimosus under the conditions that were not equivalent to the ones applied here. It proves once again that the application of microparticles to enhance product titers should not be perceived as a ready-to-use solution but rather as a promising basis for further process optimization efforts, as was mentioned above with regard to lovastatin formation.…”

“…One of the key factors to consider is the concentration of microparticles. It was shown in the same work of Kuhl et al ( 2021 ) that the presence of talc can lead either to the increase or decrease of oxytetracycline levels depending on its concentration in the medium. In many other studies focused on MPEC, the concentration of microparticles was found to be an important factor in the context of stimulating the production of metabolites and enzymes (Antecka et al 2016b ; Coban and Demirci 2016 ; Driouch et al 2010a , 2012 ; Kaup et al 2008 ; Gonciarz and Bizukojc 2014 ; Yatmaz et al 2016 ).…”

“…The production of oxytetracycline by S. rimosus was recently shown to be enhanced by the addition of mineral microparticles (Kuhl et al 2021 ). Here, AO failed to stimulate oxytetracycline biosynthesis (Fig.…”

Effect of Microparticles on Fungal Fermentation for Fermentation-Based Product Productions

“…For example, talc could be one of the preferable microparticle owing to its price in the range of 10 EUR cents per kg. Moreover, it could be evaluated in feed additives and fertilizers by co-harvested with biomass after fermentation process [77].…”

Properties of Spontaneous rpsL Mutant of Streptomyces albus KO-1297

“…The improvement of biotechnological potential of S. albus J1074 was an important direction of studies, in the course of which new derivatives of this strain, plasmids for the expression of global regulators of the secondary metabolism were constructed, and different cultivation techniques providing a maximal productivity of this platform were worked out (Lopatniuk et al, 2017;Gummerlich et al, 2021;Kuhl et al, 2021). The selection of highly productive variants among streptomycin-resistant (Str R ) Streptomyces mutants is one of the historically first approaches to obtaining overproducers of antibiotics; most frequently, such mutations occur in the rpsL gene encoding the ribosomal protein S12 (Shima et al, 1996).…”