Departamento de Engenharia e Tecnologia de Alimentos, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista , São José do Rio Preto, SP , Brasil.
Braz J Microbiol. 2012 Oct;43(4):1536-44. doi: 10.1590/S1517-838220120004000038. Epub 2012 Jun 1.
This work is aimed to produce endoglucanase through solid state fermentation in a packed bed bioreactor with the use of the fungus Myceliophtora sp. I-1D3b using a mixture of wheat bran (WB) and sugar cane bagasse (SCB) as culture medium. Preliminary tests were performed in polypropylene plastic bags, controlling the variables temperature (40, 45, and 50°C), initial moisture content (75, 80, and 85%, w.b.), and weight proportion SCB/WB (1:1, 7:3, and 9:1). The highest enzyme activities in plastic bags were obtained using the substrate proportion of 7:3, 50°C temperature, and 80% initial moisture content (878 U/grams of dry solid). High activities of filter-paper cellulase and xylanase were also obtained in plastic bags and some results are reported. For the packed bed experiments, the temperature (45 and 50°C) and the air flow rate (80, 100 and 120L/h) were the controlled variables. Activity of endoglucanase was similar to plastic bag tests. A longitudinal gradient of moisture content, was observed increasing from the bottom to the top of the reactor, even though the longitudinal enzyme activity profile was flat for almost the whole bed. Air flow rate did not affect enzyme activity, while experiments carried out at 50°C showed higher enzyme activities. The maximum temperature peak observed was at about 6°C above the process temperature.
本工作旨在使用真菌 Myceliophtora sp. I-1D3b 通过固态发酵在填充床生物反应器中生产内切葡聚糖酶,使用麦麸(WB)和甘蔗渣(SCB)混合物作为培养基。初步试验在聚丙烯塑料袋中进行,控制变量为温度(40、45 和 50°C)、初始水分含量(75、80 和 85%,w.b.)和 SCB/WB 重量比例(1:1、7:3 和 9:1)。在塑料袋中使用底物比例为 7:3、50°C 温度和 80%初始水分含量(878 U/克干固体)时,可获得最高的酶活。在塑料袋中也获得了滤纸纤维素酶和木聚糖酶的高活性,并且报告了一些结果。对于填充床实验,控制变量为温度(45 和 50°C)和空气流速(80、100 和 120L/h)。内切葡聚糖酶的活性与塑料袋试验相似。即使在整个床层几乎平坦的情况下,也观察到反应器底部到顶部的水分含量呈纵向梯度增加。空气流速对酶活性没有影响,而在 50°C 下进行的实验显示出更高的酶活性。观察到的最高温度峰值约比工艺温度高 6°C。