This study aimed to investigate the production of biobased volatile fatty acids (VFAs) from pretreated olive mill solid waste (OMSW). Three hydrothermal pretreatment (HP) conditions (D1: 125 ºC, 53 min; D2: 161 ºC, 62 min; D3: 191 ºC, 83 min) were selected. The pretreated olive mill solid fraction (OMSF), pretreated olive mill liquid fraction (OMLF), and pretreated OMSW were evaluated as potential substrates for acidification in the anaerobic digestion (AD) in liquid (L-AD), semi-solid (Ss-AD), and solid (S-AD) phases. The best acidification efficiency (AE) observed in this study was 65%, for L-AD and HP condition D2 (161 ºC, 62 min). However, the HP condition D2 applied to the Ss-AD provided a VFA concentration of 18218 mg L⁻¹, about 6-fold higher than that observed in the L-AD system. Polyphenols changed the profile of VFAs, increasing the production of longer chain VFAs in the L-AD and S-AD systems. Also, the influence of the typology of the AD system and HP severity on the microbial community was evaluated. Proteobacteria and Firmicutes were the most representative phyla in acidogenic fermentation of OMSW substrates and the genera Enterobacter, Pseudomonas, Achromobacter, Clostridium, Ochrobactrum, and Peptoclostridium played an important role in the pretreated OMSW fermentation and, consequently, in the VFAs production profile.

这项研究旨在调查从预处理的橄榄磨坊固体废物（OMSW）生产生物基挥发性脂肪酸（VFA）的过程。选择了三种水热预处理（HP）条件（D1：125ºC，53分钟； D2：161ºC，62分钟； D3：191ºC，83分钟）。预处理的橄榄研磨机固体部分（OMSF），预处理的橄榄研磨机液体部分（OMLF）和预处理的OMSW被评估为在液体（L-AD），半固体（Ss- （AD）和固相（S-AD）。在L-AD和HP条件D2（161ºC，62分钟）下，本研究中观察到的最佳酸化效率（AE）为65％。但是，应用于Ss-AD的HP条件D2提供的VFA浓度为18218 mg L ^-1大约是L-AD系统中观察到的6倍。多酚改变了VFA的特性，增加了L-AD和S-AD系统中较长链VFA的产量。此外，还评估了AD系统类型和HP严重性对微生物群落的影响。在OMSW底物的产酸发酵中，Proteobacteria和Firmicutes是最有代表性的菌群，肠杆菌属，假单胞菌属，无色杆菌，梭状芽孢杆菌，O盖菌和拟肽菌属在预处理的OMSW发酵中以及VFAs的生产过程中起着重要的作用。