Development of an animal-derived component-free medium for Spodoptera frugiperda (Sf9) cells using response surface methodology.

OBJECTIVES: To develop an animal-derived component-free medium for Spodoptera frugiperda (Sf9) growth and green fluorescent protein (GFP) expression. RESULTS: OSF9-ADCFM contained optimum concentrations of CDLC, YE and ST at 0.5% (v/v), 11.0 g/L, and 3.0 g/L, respectively. A mean viable cell concentration of 1.71 ± 0.14 × 105 cells/mL was obtained from 5 passages (P1-P5). The use of both peptones after 10 kDa ultrafiltration had a significant effect on Sf9 cell growth. Grace's insect medium with 10% FBS gave higher un-infected cell number than SF-900II and OSF9-ADCFM for 4.29 and 5.38 times, respectively. The average cell number of un-infected cells and GFP-fluorescent cells of SF-900II were higher than OSF9-ADCFM 1.25 and 7 times, respectively. CONCLUSION: In-house OSF9-ADCFM could support growth and GFP expression in Sf9 less than commercial SF-900II. However, it could lower the production cost at least 50% comparing to commercial SF-900II. The development of in- house OSF9-ADCFM would be continued to increase both cell numbers and protein expression in the next step.

Determination of bioactive compounds, antimicrobial activity, and the phytochemistry of the organic banana peel in Thailand

Banana fruit is enriched with phytonutrients, minerals, and its peel, which is mostly discarded as waste. This research aimed to study its bioactive compound properties, antimicrobial activity, and identify and characterize the constituents of organic banana peel extract (BPE), composed of six species (i.e., Kluai Homthong, Kluai Namwa, Kluai Kai, Kluai Hukmook, Kluai Lebmuernang, and Kluai Homtaiwan). Total phenolic content (TPC), antioxidant content, and ferric-reducing antioxidant power (FRAP) were important in BPE of Kluai Kai. BPE of Kluai Hukmook could inhibit Aeromonas hydrophila and Staphylococcus aureus. The Fourier-transform infrared spectroscopy (FTIR) spectrum exposed diverse compounds of primary and secondary phytochemicals. Four main constituents, including acetic acid, formic acid, 1,2-benzenediol,3-methyl-, and 4-hydroxy-2-methylacetophone derived from gas chromatography-mass spectroscopy (GC-MS), demonstrated their antioxidant properties and antimicrobial activity. This result suggests that organic banana peel can both be applied as an antioxidant and antimicrobial substance. BPE increases the value of banana peels (BPs) and reduces the burden of its waste disposal in the environment.