Unveiling molecular changes in guabiju during Aspergillus brasiliensis cultivation: insights from untargeted metabolomics

Black aspergilli exhibit remarkable bioconversion potential by transforming plant matrices into bioactive compounds, although their metabolic processes remain underexplored. This study investigated the biotransformation of metabolites during the solid-state cultivation of guabiju (Myrcianthes pungens) by Aspergillus brasiliensis using an LC-MS-based untargeted metabolomics approach, aiming to elucidate dynamic changes in metabolite profiles over 0, 3, 7, 10 and 15 days of cultivation. Key metabolites, such as gallic acid, epigallocatechin, mono- and di- O-galloylquinic acids, quercetin and citric acid, increased during cultivation, with a significant rise in gallic acid release and citric acid production observed after seven days. Fungal metabolites including hexylitaconic acid also increased, indicating potential to produce itaconic acid-derived compounds. Data analysis indicated that most significant metabolic changes occurred within the first seven days, especially for tannin hydrolysis and organic acid production. These findings highlighted the potential of A. brasiliensis to enhance fermented foods through targeted biotransformation.

黑曲霉类群（Black aspergilli）具备将植物基质转化为生物活性化合物的出色生物转化潜力，但其代谢过程仍有待深入探究。本研究采用基于液相色谱-质谱联用（Liquid Chromatography-Mass Spectrometry，LC-MS）的非靶向代谢组学（untargeted metabolomics）方法，探究了巴西曲霉（Aspergillus brasiliensis）固态发酵刺果番樱桃（guabiju，*Myrcianthes pungens*）过程中的代谢物生物转化情况，旨在阐明发酵0、3、7、10和15天时代谢物谱的动态变化。发酵过程中，没食子酸（gallic acid）、表没食子儿茶素（epigallocatechin）、单-O-没食子酰奎宁酸、二-O-没食子酰奎宁酸、槲皮素（quercetin）及柠檬酸（citric acid）等关键代谢物含量均有所上升，其中第7天后没食子酸释放量与柠檬酸产量显著提升。包括己基衣康酸（hexylitaconic acid）在内的真菌代谢物含量也有所上升，表明该菌株具备生产衣康酸（itaconic acid）衍生化合物的潜力。数据分析显示，绝大多数显著代谢变化发生在前7天内，尤其体现在单宁水解与有机酸生成过程中。本研究结果凸显了巴西曲霉（A. brasiliensis）通过定向生物转化优化发酵食品品质的应用潜力。