The effects of allelopathy and the potential harm of several isolated allelochemicals have been studied in detail. Microorganisms in the phycosphere play an important role in algal growth, decay and nutrient cycling. However, it is unknown and often neglected whether allelochemicals affect the phycosphere. The present study selected a phenolic acid protocatechuic acid (PA) – previously shown to be an allelochemical. We studied PA at a half maximal effective concentration of 0.20 mM (30 mg L⁻¹) against Scrippsiella trochoidea to assess the effect of PA on its phycosphere in an acute time period (48 h). The results showed that: 1) OTUs (operational taxonomic units) in the treatment groups (31.4 ± 0.55) exceeded those of the control groups (28.2 ± 1.30) and the Shannon and Simpson indices were lower than the control groups (3.31 ± 0.08 and 0.84 ± 0.02, 3.45 ± 0.09 and 0.88 ± 0.01); 2) Gammaproteobacteria predominated in the treatment groups (44.71 ± 2.13 %) while Alphaproteobacteria dominated in the controls (67.17 ± 3.87 %); 3) Gammaproteobacteria and Alphaproteobacteria were important biomarkers in the treatment and control groups respectively (LDA > 4.0). PA improved the relative abundance of Alteromonas significantly and decreased the one of Rhodobacteraceae. PICRUSt analysis showed that the decrease of Rhodobacterceae was closely related with the decline of most functional genes in metabolism such as amino acid, carbohydrate, xenobiotics, cofactors and vitamins metabolism after PA-treated.

已详细研究了化感作用的影响以及几种分离的化感物质的潜在危害。藻圈中的微生物在藻类生长，腐烂和养分循环中起重要作用。然而，未知化感物质是否会影响藻圈。本研究选择了酚酸原儿茶酸（PA）–先前已证明是一种变构化学物质​​。我们研究了对草根癣菌最大有效浓度为0.20 mM（30 mg L ^-1）的一半的PA以评估PA在急性期（48小时）对其藻圈的影响。结果表明：1）治疗组的OTU（操作分类单位）（31.4±0.55）超过了对照组（28.2±1.30），并且Shannon和Simpson指数低于对照组（3.31±0.08和0.84±0.02、3.45±0.09和0.88±0.01）；2）丙种杆菌在治疗组中占主要地位（44.71±2.13％），而丙种杆菌在对照组中占主要地位（67.17±3.87％）；3）丙种细菌和丙种细菌分别是治疗组和对照组的重要生物标志物（LDA> 4.0）。PA改善了Alteromonas的相对丰度显着降低了红细菌科之一。PICRUSt分析表明，PA处理后，红细菌的减少与代谢中大多数功能基因的减少密切相关，例如氨基酸，碳水化合物，异种生物，辅因子和维生素的代谢。