The catalyst was removed by filtration through Celite, and concentration of the filtrate gave 23 (171 mg, 91%).
Microspheres were isolated from the mixture by filtration through a 0.45-µm PTFE filter (4555, Pall Corporation, Russia).
Culture supernatants containing the autoinducer were collected and sterilized by filtration through 0.22-μm pore-sized filters.
Any additional cell debris was removed from the medium by filtration through 0.22-μm PES membrane filters (Thermo Fisher Scientific).
After homogenization, the extracted materials were obtained by filtration through filter paper (Whatman no. 1).
The extracts were separated from the material residue by filtration through Whatman No. 1 filter paper.
Juice was obtained by a juicer (HR1861, Philips Co. Beijing, China), followed by filtration through cheesecloth.
Particles were sterilized by filtration through a 0.22 μm polyethersulfone filter.
All stock solutions were autoclaved, except for the vitamin solution, which was sterilized by filtration through 0.22 μm filter membranes.
The reaction mixture was sterilized by filtration through a 0.22-μm Millex GV filter (Merck Millipore, Billerica, MA, USA).
Stabilizer solution with enzymes was sterilized by filtration through 0.22 μm membrane filter (Millex, Millipore, Co Cork, Ireland).
