Abstract

This research aimed to study gallic acid production by the activity of tannase secreted by Aspergillus niger ATCC 16888 under solid-state fermentation using Triphala waste. Gallic acid is commonly extracted from Triphala using hot water. The residue contains a high number of hydrolyzable tannins. The parameters for the SSF were studied which included a nitrogen supplementary with an aeration supply. Results indicated that Triphala waste (TW) was a good substrate for valorization with tannase and gallic acid production by A. niger. When the fermentation was supplemented with 0.75% sodium nitrate that combination provided the highest biomass, tannase and gallic acid concentrations of 254.2 ± 15.4 mg g⁻¹_DS, 49.4 ± 2.0 U g⁻¹_DS and 13.3 mg g⁻¹_DS, respectively, while the aeration at 0.3 vvm (0.75% sodium nitrate supplementary) provided the highest biomass tannase and gallic productions of 445.0 ± 43.0 mg g⁻¹_DS, 53.3 ± 5.3 U g⁻¹_DS and 168.5 ± 5.0 mg g⁻¹_DS, respectively. The results indicated that the number of nitrogen atoms and the rate of aeration had significant parameters for tannase production. The carbon/nitrogen (C/N) ratio of the substrate correlated with tannase production of A. niger. The optimum C/N ratio of the substrate for tannase production was approximately 20.

摘要

本研究旨在研究黑曲霉ATCC 16888 分泌的鞣酸酶活性在利用三果菌废物进行固态发酵的情况下生产没食子酸。没食子酸通常是用热水从三果果中提取的。残留物含有大量可水解单宁。研究了 SSF 的参数，其中包括具有曝气供应的氮气补充。结果表明，三果菌废物 (TW) 是黑曲霉鞣酸酶和没食子酸生产增值的良好底物。当发酵过程中补充 0.75% 硝酸钠时，该组合提供了最高的生物量、鞣酸酶和没食子酸浓度，分别为 254.2  ± 15.4 mg g ⁻¹ _DS、 49.4 ± 2.0 U g ⁻¹_分别为DS和 13.3 mg g ⁻¹ _DS，而 0.3 vvm（补充 0.75% 硝酸钠）的曝气提供了最高的生物量鞣酸酶和没食子产量，分别为 445.0 ± 43.0 mg g ⁻¹ _DS、 53.3 ± 5.3 U g ⁻¹ _DS和 168.5 ± 5.0 mg g ^-1 _DS，分别。结果表明，氮原子数和通气速率对于鞣酸酶的生产具有重要参数。底物的碳/氮（C/N）比与黑曲霉鞣酸酶的产生相关。用于鞣酸酶生产的底物的最佳C/N比约为20。