Xiao Zhizhuang, Bergeron Hélène, Lau Peter C K
Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montreal, QC, H4P 2R2, Canada.
Antonie Van Leeuwenhoek. 2012 May;101(4):837-44. doi: 10.1007/s10482-012-9700-8. Epub 2012 Jan 28.
This study describes the release of antioxidant ferulic acid from wheat and triticale brans by mixtures of extracellular enzymes produced in culture by a strain FC007 of Alternaria alternata, a dark mold originally isolated from Canadian wood log. The genus of the mold was confirmed as Alternaria by 18S ribosomal DNA characterization. Enzyme activities for feruloyl esterase (FAE) and polysaccharide hydrolyzing enzymes were measured, and conditions for release of ferulic acid and reducing sugars from the mentioned brans were evaluated. The highest level of FAE activity (89 ± 7 mU ml(-1) fermentation culture) was obtained on the fifth day of fermentation on wheat bran as growth substrate. Depending on biomass and processing condition, up to 91.2 or 72.3% of the ferulic acid was released from wheat bran and triticale bran, respectively, indicating the proficiency of A. alternata extracellular enzymes in plant cell wall deconstruction. The apparent high extraction of ferulic acid from wheat and triticale brans represents a potential advantage of using a whole fungal cell enzyme complement over yields reported previously through an artificial assembly of cloned FAE with a particular xylanase in a cocktail format.
本研究描述了链格孢菌FC007菌株（最初从加拿大原木中分离出的一种暗色霉菌）在培养过程中产生的细胞外酶混合物从小麦麸皮和小黑麦麸皮中释放抗氧化剂阿魏酸的情况。通过18S核糖体DNA表征确定该霉菌的属为链格孢属。测定了阿魏酸酯酶（FAE）和多糖水解酶的酶活性，并评估了从小麦麸皮和小黑麦麸皮中释放阿魏酸和还原糖的条件。以麦麸为生长底物，在发酵的第五天获得了最高水平的FAE活性（89±7 mU ml(-1)发酵培养液）。根据生物量和加工条件，分别从小麦麸皮和小黑麦麸皮中释放出高达91.2%或72.3%的阿魏酸，这表明链格孢菌的细胞外酶在植物细胞壁解构方面具有高效性。从小麦麸皮和小黑麦麸皮中明显高提取率的阿魏酸代表了使用完整真菌细胞酶组合相对于先前通过将克隆的FAE与特定木聚糖酶以鸡尾酒形式人工组装所报道的产量的潜在优势。
