spore suspension was prepared to a final concentration of 5 10mL1 in sterile water. A 200-mL spore suspension was transferred into a 15-mL conical flask containing 5 mL DCWB medium. The flasks were incubated on a shaker at 28C, 180 rpm for 4 d. Extraction was carried out at 50C for 30 min with preconditioned PA fiber (85mM, polyacrylate) in the headspace.