Feitkenhauer Heiko, Fischer Daniel, Fäh Daniel
Laboratory of Chemical Engineering and Industrial Chemistry, ETH-Zürich, Hönggerberg HCI, CH-8093 Zürich, Switzerland.
Biotechnol Prog. 2003 May-Jun;19(3):874-9. doi: 10.1021/bp025790q.
A film of sizing agents protects yarn during weaving. Its removal in a subsequent washing process causes 50% of the organic effluent load of textile finishing processes and requires large amounts of auxiliary chemicals (e.g., surfactants). Microbial desizing is a new bioprocess that uses the acidifying culture of a two-phase anaerobic digestion plant for the removal and partial degradation (acidification) of the sizing agent. Soluble starch is used in this study to characterize the enzymatic properties in the supernatant of the desizing culture and to link them to desizing efficiencies. The supernatant of the culture (grown at 37 degrees C, pH 5.5) displayed the highest enzymatic activity between pH 4 and 5 and in a broad temperature range (20-80 degrees C). Highest metabolization rates were determined with the substrate amylose. Short chain dextrins (average of 5 and 10 glucose units) and amylopectin were converted significantly more slowly. At 37 degrees C the half-life time of the enzymatic activity in the supernatant was 45 h. In a desizing test a decisive reduction of the chain length was found already after 1 h (allowing starch solubilization). A microbial desizing experiment with dyed, native maize starch demonstrated the efficiency of the proposed bioprocess.
在织造过程中，上浆剂形成的薄膜可保护纱线。在后续的洗涤过程中去除上浆剂会产生纺织后整理过程中50%的有机废水负荷，并且需要大量辅助化学品（如表面活性剂）。微生物退浆是一种新的生物工艺，它利用两相厌氧消化装置的酸化培养物来去除和部分降解（酸化）上浆剂。本研究使用可溶性淀粉来表征退浆培养物上清液中的酶特性，并将其与退浆效率联系起来。培养物的上清液（在37℃、pH 5.5条件下生长）在pH 4至5以及较宽的温度范围（20 - 80℃）内表现出最高的酶活性。以直链淀粉为底物时测定的代谢率最高。短链糊精（平均5和10个葡萄糖单位）和支链淀粉的转化明显更慢。在37℃时，上清液中酶活性的半衰期为45小时。在退浆试验中，仅1小时后就发现链长有决定性的缩短（使淀粉溶解）。用染色的天然玉米淀粉进行的微生物退浆实验证明了所提出的生物工艺的效率。
