Dynamic social interactions and keystone species shape the diversity and stability of mixed-species biofilms – an example from dairy isolates - Dataset

We previously reported a bacterial four-species biofilm model comprising Stenotrophomonas rhizophila (SR), Bacillus licheniformis (BL), Microbacterium lacticum (ML), and Calidifontibacter indicus (CI) that were isolated from the surface of a dairy pasteuriser after cleaning and disinfection. These bacteria produced 3.13-fold more biofilm mass compared to the sum of biofilm masses in monoculture (https://doi.org/10.3389/fmicb.2023.1159434). In a subsequent experiment we confirmed that the observed community synergy resulted from dynamic social interactions among various species pairs, encompassing commensalism, exploitation, and amensalism. M. lacticum appeared to be the keystone species as it increased the growth of all other species that led to the synergy in biofilm mass. Interactions among the other three species (in the absence of M. lacticum) also contributed towards the synergy in biofilm mass. Bacterial cell-free-supernatants were also investigated to assess the nature of the observed synergy. The first four sheets of the Excel file contain raw cell count data for the four species (SR, BL, ML, and CI), recorded every 4 h over a 24 h period on the surface of stainless steel (SS) in the presence of brain-heart-infusion (BHI) medium and skim-milk (SM). Data related to individual bacterial cell counts in various mixed-species biofilms are also presented. These biofilms were developed on SS in BHI for h.  Data related to bacterial biofilm masses in different mixed-species biofilm combinations are also presented, showcasing the effect of replacing one strain with its CFS. Species written in red indicate that their CFS was used, not their viable form.

本课题组此前报道了一种四菌种细菌生物被膜模型，包含嗜根寡养单胞菌（Stenotrophomonas rhizophila, SR）、地衣芽孢杆菌（Bacillus licheniformis, BL）、乳酸微杆菌（Microbacterium lacticum, ML）以及印度卡利丰杆菌（Calidifontibacter indicus, CI），上述菌株均分离自清洁消毒后的乳品巴氏杀菌机表面。与单菌种培养的生物被膜总质量相比，该四菌种模型的生物被膜质量高出3.13倍（参考文献：https://doi.org/10.3389/fmicb.2023.1159434）。

后续实验证实，该群落的协同效应源于不同菌种对间的动态种间互作，涵盖偏利共生、掠夺互作及偏害共生三种类型。乳酸微杆菌（ML）似乎是该群落的关键物种，其可促进其余所有菌种的生长，进而驱动生物被膜质量的协同提升。在剔除乳酸微杆菌的前提下，其余三个菌种间的互作同样对生物被膜质量的协同效应具有贡献。

本研究同时通过细菌无细胞上清液（cell-free-supernatant, CFS）探究了该协同效应的本质。Excel文件的前四个工作表包含四菌种（SR、BL、ML、CI）的原始细胞计数数据：实验于不锈钢（SS）表面开展，以脑心浸液（brain-heart-infusion, BHI）培养基与脱脂乳（skim-milk, SM）为培养体系，每4小时记录一次细胞计数，持续时长为24小时。

数据集同时收录了多种混合菌种生物被膜中各单菌种的细胞计数相关数据。该类生物被膜于不锈钢表面的脑心浸液培养基中培养[原文此处时长标注缺失]。数据集还收录了不同混合菌种生物被膜组合的细菌生物被膜质量相关数据，用以展示用菌株的无细胞上清液替换该菌株本身的实验效应。标注为红色的菌种代表实验中使用了其无细胞上清液，而非活菌形式。