An infrared balance (Denver Instrument, IR 35) was adopted to rapidly measure the biomass concentration. Five milliliters of broth was centrifuged at 7000 rpm for 10 min. After removing the supernatant, about an equal volume of distilled water was added to eliminate impurities. This washing procedure was performed several times, and the final liquor was dried using the infrared balance at 150 °C to evaporate the water content