Mata-Gómez Marco A, Heerd Doreen, Oyanguren-García Iñigo, Barbero Francis, Rito-Palomares Marco, Fernández-Lahore Marcelo
Downstream Bioprocessing Laboratory, School of Engineering and Science, Jacobs University, D-28759, Bremen, Germany; Centro de Biotecnología-FEMSA, Tecnológico de Monterrey, Monterrey, NL, 64849, Mexico.
J Sci Food Agric. 2015 May;95(7):1554-61. doi: 10.1002/jsfa.6864. Epub 2014 Sep 2.
In the food industry, the use of pectinase preparations with high pectin esterase (PE) activity leads to the release of methanol, which is strictly regulated in food products. Herein, a pectin-degrading enzyme (PDE) complex exhibiting low PE activity of three Aspergillus sojae ATCC 20235 mutants (M3, DH56 and Guserbiot 2.230) was investigated. Production of exo-/endo-polygalacturonase (PG), exo-polymethylgalacturonase (PMG) and pectin lyase (PL) by mutant M3 and A. sojae using two different carbon sources was evaluated in solid-state fermentation. Finally, experimental preparations obtained from the mutants and commercial pectinases standardized to the same potency were screened for PDEs.
Mutant M3 grown on sugar beet was found to be the best producer of exo-PG, endo-PG, exo-PMG and PL, with maximum yields of 1111, 449, 130 and 123 U g(-1), respectively. All experimental preparations exhibited low PE activity, at least 21.5 times less than commercial pectinases, and higher endo-PG (40 U mL(-1)).
Mutant M3 was the best PDE producer using sugar beet. Mutant strains presented a PDE complex featuring high endo-PG and very low PE activities. This novel complex with low de-esterifying activity can be exploited in the food industry to degrade pectin without releasing methanol.
在食品工业中，使用具有高果胶酯酶（PE）活性的果胶酶制剂会导致甲醇的释放，而甲醇在食品中的含量受到严格监管。在此，对三种酱油曲霉ATCC 20235突变体（M3、DH56和Guserbiot 2.230）所产生的具有低PE活性的果胶降解酶（PDE）复合物进行了研究。在固态发酵中，评估了突变体M3和酱油曲霉利用两种不同碳源生产外切/内切聚半乳糖醛酸酶（PG）、外切聚甲基半乳糖醛酸酶（PMG）和果胶裂解酶（PL）的情况。最后，对从突变体获得的实验制剂和标准化至相同效力的商业果胶酶进行了PDE筛选。
发现在甜菜上生长的突变体M3是外切PG、内切PG、外切PMG和PL的最佳生产者，最大产量分别为1111、449、130和123 U g(-1)。所有实验制剂的PE活性均较低，至少比商业果胶酶低21.5倍，且内切PG活性较高（40 U mL(-1)）。
突变体M3是使用甜菜的最佳PDE生产者。突变菌株呈现出一种具有高内切PG活性和极低PE活性的PDE复合物。这种具有低脱酯活性的新型复合物可用于食品工业中降解果胶而不释放甲醇。
