2.6. Fermentation experiments
Batch culture experiments were carried out in pH-controlled 500 ml fleakers with a working volume of 350 ml under semianaerobic conditions essentially as described previously . Rice hull hydrolyzate was used as substrate. The medium was prepared by dissolving 10 g tryptone and 5 g yeast extract in the diluted hydrolyzate (per l) and autoclaving at 121 ◦C for 15 min. A 4M KOH solutionwas used for pH control. Samples were withdrawn periodically to determine cell density, residual sugars, and ethanol and stored at −20 ◦C prior to analysis. Base consumption and pH were also recorded. For SHF experiments, the fermentation was performed at pH 6.5, 35 ◦C and 130 rpm using the liquid portion of the enzymatically saccharified rice hull hydrolyzate. For SSF experiments, 2 l fermenters (Biostat B, B. Braun Biotech International, Allentown, PA) with working volumes of 1.5 l were used at pH 6.0 and 35 ◦C at the agitation rate of 150 rpm. The alkaline peroxide pretreated whole rice hull hydrolyzate was added to the fermenter as substrate after diluting three times and adjusting the pH to 6.0 with concentrated HCl before adding enzymes and inoculum. Inoculum size was 5% (v/v) in both cases.
- 1 0 年前最佳解答
2.6. 發酵實驗批文化實驗如所描述早先根本上被執行了在酸鹼度受控500 機器語言fleakers 以350 機器語言的工作容量在semianaerobic 情況下[ 15 ] 。米船身hydrolyzate 被使用了作為基體。媒介由溶化準備了10 g tryptone 和5 g 酵母抽提物在被稀釋的hydrolyzate (每l) 和真空加熱在121?C 15 分鐘。4M KOH solutionwas 被使用為酸鹼度控制。樣品階段性地被撤出確定細胞密度、殘餘的糖, 和對氨基苯甲酸二和被存放了在?20?C 在分析之前。基本的消耗量和酸鹼度並且被記錄了。為SHF 實驗, 發酵進行了在酸鹼度6.5, 35?C 和130 轉每分鐘使用enzymatically 糖化的米船身hydrolyzate 的液體部份。為SSF 實驗, 2 升發酵桶(Biostat B, B. Braun Biotech 國際, Allentown, PA) 以1.5 升的工作容量被使用了在酸鹼度6.0 和35?C 以150 轉每分鐘的鼓動率。鹼性過氧化物被預處理的整體米船身hydrolyzate 增加了來發酵桶作為基體在稀釋三次和調整酸鹼度以後到6.0 與被集中的HCl 在增加酵素和接種物之前。接種物大小是5% (v/v) 在兩個案件。
- 3 年前