Department of Biology, Georgia State University, Atlanta, GA 30303, USA.
Appl Microbiol Biotechnol. 2010 May;86(6):1941-6. doi: 10.1007/s00253-010-2473-y. Epub 2010 Feb 24.
Rationally-assembled multispecies biofilms could benefit applied processes including mixed waste biodegradation and drug biosynthesis by combining complementary metabolic pathways into single functional communities. We hypothesized that the cellular composition of mature multispecies biofilms could be manipulated by controlling the number of each cell type present on newly colonized surfaces. To test this idea, we developed a method for attaching specific numbers of bacteria to a flow cell by recirculating cell suspensions. Initial work revealed a nonlinear relationship between suspension cell density and areal density when two strains of Escherichia coli were simultaneously recirculated; in contrast, sequential recirculation resulted in a predictable deposition of cell numbers. Quantitative analysis of cell distributions in 48-h biofilms comprised of the E. coli strains demonstrated a strong relationship between their distribution at the substratum and their presence in mature biofilms. Sequentially depositing E. coli with either Pseudomonas aeruginosa or Bacillus subtilis determined small but reproducible differences in the areal density of the second microorganism recirculated relative to its areal density when recirculated alone. Overall, the presented method offers a simple and reproducible way to construct multispecies biofilms with defined compositions for biocatalytic processes.
理性组装的多物种生物膜可以通过将互补的代谢途径组合到单个功能群落中，从而有益于应用过程，包括混合废物生物降解和药物生物合成。我们假设，通过控制新定植表面上每种细胞类型的数量，可以操纵成熟多物种生物膜的细胞组成。为了验证这一想法，我们开发了一种通过循环细胞悬浮液将特定数量的细菌附着到流动池的方法。初步研究表明，当同时循环两种大肠杆菌菌株时，悬浮细胞密度与比表面积密度之间存在非线性关系；相比之下，顺序循环导致细胞数量的可预测沉积。由大肠杆菌菌株组成的 48 小时生物膜的细胞分布的定量分析表明，它们在基质上的分布与成熟生物膜中的存在之间存在很强的关系。顺序沉积大肠杆菌，然后是铜绿假单胞菌或枯草芽孢杆菌，相对于单独循环时，可循环的第二种微生物的比表面积密度存在微小但可重复的差异。总的来说，所提出的方法为具有定义组成的生物催化过程构建多物种生物膜提供了一种简单且可重复的方法。
