How to culture bitoXibacillin for spider mite control? - briefly
Cultivate bitoXibacillin in a sterile liquid nutrient broth at 28 °C with agitation (≈150 rpm) for 24–48 hours until the culture reaches an optical density of ~0.8, then dilute to 10⁶ CFU ml⁻¹ and spray onto spider‑mite‑infested foliage.
How to culture bitoXibacillin for spider mite control? - in detail
Cultivating bitoXibacillin for spider‑mite management requires a sterile environment, defined medium composition, and precise incubation parameters. Begin by preparing a liquid broth containing glucose (20 g L⁻¹), yeast extract (5 g L⁻¹), peptone (10 g L⁻¹), and a phosphate buffer adjusted to pH 6.8. Autoclave the mixture at 121 °C for 15 minutes, then cool to room temperature under laminar flow.
Inoculate the sterile broth with a pure colony of bitoXibacillin derived from a glycerol stock (10 % v/v). Incubate the culture in a shaking incubator at 28 °C with an agitation speed of 150 rpm. Monitor optical density at 600 nm; target a value of 0.8–1.0, which corresponds to the late exponential phase optimal for metabolite production.
Once the desired growth stage is reached, transfer the culture to a fermenter for scale‑up. Maintain dissolved oxygen above 30 % saturation by adjusting airflow to 1 L min⁻¹ and increasing agitation to 300 rpm. Keep temperature constant at 28 °C and pH stable at 6.8 using automatic NaOH/HCl dosing. Ferment for 48 hours, sampling every 12 hours to assess bitoXibacillin concentration via high‑performance liquid chromatography.
After fermentation, separate cells by centrifugation at 5 000 g for 10 minutes. Filter the supernatant through a 0.22 µm membrane to remove residual debris. Concentrate the filtrate using rotary evaporation at 40 °C, then spray‑dry the concentrate with an inlet temperature of 180 °C and an outlet temperature of 80 °C. The resulting powder should be stored at –20 °C in airtight containers until application.
For field deployment, dissolve the powder in water to a concentration of 1 g L⁻¹. Add a non‑ionic surfactant (0.1 % v/v) to improve leaf coverage. Apply the solution to infested crops using a calibrated sprayer, ensuring thorough wetting of foliage. Repeat applications at 7‑day intervals during peak mite activity, monitoring population levels to adjust dosage as needed.