Freezone plus 6 liter cascade console freeze dry system

The concentrated neutral and acidic samples were fractionated using size exclusion chromatography (FPLC Amersham-Biosciences, Akta system 890) with an XK 260 × 1000 mm column (GE Healthcare) packed with P2 gel (200–400 mesh, separation range of 100–1800 MW, Biorad Laboratories, Hercules, CA, USA). The instrument was equipped with both Ultra-Violet and conductivity detectors (GE Healthcare). Water was used as eluent solvent. A flow rate of 1.0 mL/min was used and a 5-mL sample was injected for each run. 5 mL of concentrated neutral fractions (containing 670 mg oligosaccharides) and acidic fractions (containing 140 mg oligosaccharides) were injected into the SEC column after a 500-mL void volume. 90 fractions (A1-12, B1-12, C1-12, D1-12, E1-12, F1-12, G1-12, H1-6, 10 mL in each tube) were collected. Fractions in the same row were pooled and lyophilized into dry sample A–H by a freeze-dryer (FreeZone Plus 6 Liter Cascade Console Freeze Dry System, LABCONCO).

To assess the shelf-life of bacterial cells as an organic adsorbent, heat-inactivated cells were collected by the freeze-drying technique using the FreeZone Plus 6 Liter Cascade Console Freeze Dry System (Labconco, Kansus City, MO, USA). Freeze-dried cells were stored at room temperature in a desiccator before testing for ZEA removal. The bacterial cells were used to check the ZEA binding activity after being kept for 0, 5, 10, 30, 60, and 90 days of storage.

WSC were extracted from the crude lignin stream produced during EA pretreatment process. Distilled water was added and vortex-mixed with the lignin stream in a 10:1 (volume to mass) ratio. Water extraction was conducted in shake flask by incubating the samples in an incubator maintained at 50 °C for 2 h at 250 rpm. After the 2 h washing and extraction, the slurry was cooled to 4°C, and was then centrifuged and filtered through glass fiber filter (pore size 10 um). The filtrate was collected as WSC and lyophilized using a freeze dryer (Free Zone plus 6 Liter Cascade Console Freeze Dry System, LABCONCO). The WSC was further used for composition analysis, ethyl acetate extraction, and yeast fermentation.