Optimization of cytotoxic activity of Nocardia sp culture broths using a design of experiments

Abstract

In the context of research for new cytotoxic compounds, obtaining bioactive molecules from renewable sources remain a big challenge. Microorganisms and more specifically Actinobacteria from original sources are well known for their biotechnological potential and are hotspots for the discovery of new bioactive compounds. The strain DP94 studied here had shown an interesting cytotoxic activity of its culture broth (HaCaT: IC 50 = 8.0 ± 1.5 μg/mL; B16: IC 50 = 4.6 ± 1.8 μg/mL), which could not been explained by the compounds isolated in a previous work. The increase of the cytotoxic activity of extracts was investigated, based on a Taguchi L9 orthogonal array design, after DP94 culture in TY medium using two different vessels (bioreactor or Erlenmeyer flasks). Various culture parameters such as temperature, pH and inoculum ratio (%) were studied. For experiments conducted in a bioreactor, stirring speed was included as an additional parameter. Significant differences in the cytotoxic activities of different extracts on B16 melanoma cancer cell lines, highlighted the influence of culture temperature on the production of cytotoxic compound(s) using a bioreactor. A culture in Erlenmeyer flasks was also performed and afforded an increase of the production of the active compounds. The best conditions for the highest cytotoxicity (IC 50 on B16: 6 ± 0.5 μg/mL) and the highest yield (202.0 mg/L) were identified as: pH 6, temperature 37˚C and 5% inoculum.

Using Taguchi Method to Determine the Optimum Conditions for Synthesizing Parapyruvate

“…The Taguchi method is an efficient approach for the multifactor optimizing conditions with low cost and low time consumption, and has been widely applied to different areas [ 16 , 17 , 18 , 19 , 20 , 21 ]. This method uses a special design of orthogonal arrays to dispense the control factors in a balanced manner for exploring the entire control factors through a small number of experimental trials, and converts the value obtained in the experimental results into a signal-to-noise ratio (S/N) to investigate the most optimal conditions [ 22 ].…”

Antibacterial Activities and Toxicity of Streptosporangium sp. SM1P

“…PB-52 and Nocardia sp. produce antimicrobial and cytotoxic compounds, respectively (Sharma, Priyanka, Kalita, & Thakur, 2016;Noël, van Soen, Rouaud, Hitti, & Tomasi, 2020). Salinospora tropica produces various secondary metabolites with antimicrobial, anti-tumour and cytotoxic activities (Fu et al, 2020).…”