Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milano, Italy.
Pirelli Labs S.p.A., Via Piero e Alberto Pirelli 25, 20126, Milano, Italy.
Appl Microbiol Biotechnol. 2016 Oct;100(20):8931-42. doi: 10.1007/s00253-016-7691-5. Epub 2016 Jul 1.
Due to the rapid increase of waste vulcanized rubber products, the development of low-cost, efficient, and selective devulcanization processes is needed. In this paper, the devulcanization ability of Gordonia desulfuricans DSM 44462(T) was evaluated by a design of experiments. The aim of the experimental design was to investigate the importance of parameters influencing the bacterial growth, such as the glucose concentration (C), dibenzothiophene concentration (DBT), and initial biomass (optical density, OD) in biodevulcanization process. The complex viscosity (η*) was chosen as experimental response for the experimental design. A multiple linear regression was used to model the relationship between the response and the process variables. In addition, the crosslink density and gel fraction were measured. Furthermore, the automated ribosomal intergenic spacer analysis (ARISA) as a microbiological method was performed to assess the persistence of the inoculated strain during the experiments. Reduced regression models were obtained considering only the significant variables and interactions. The glucose concentration C and OD variables and C-DBT and DBT-OD interactions resulted to the relevant parameters for the process. The fingerprinting showed the persistence of G. desulfuricans DSM 44462(T), despite the presence of other bacterial population after the VGNR sterilization. These results highlight the importance to support the physics analysis with microbiological analyses to evaluate the bacterial persistence during the treatment.
由于废硫化橡胶制品的迅速增加，需要开发低成本、高效和选择性的脱硫工艺。本文通过实验设计评估了脱硫戈登氏菌 DSM 44462(T)的脱硫能力。实验设计的目的是研究影响细菌生长的参数的重要性，如生物脱硫过程中的葡萄糖浓度 (C)、二苯并噻吩浓度 (DBT)和初始生物量 (光密度，OD)。选择复合粘度 (η*)作为实验设计的实验响应。使用多元线性回归来模拟响应与过程变量之间的关系。此外，还测量了交联密度和凝胶分数。此外，还进行了自动核糖体基因间间隔分析 (ARISA) 作为微生物学方法，以评估接种菌株在实验过程中的持久性。考虑到仅显著变量和相互作用，获得了简化的回归模型。葡萄糖浓度 C 和 OD 变量以及 C-DBT 和 DBT-OD 相互作用是该过程的相关参数。指纹图谱显示，尽管在 VGNR 灭菌后存在其他细菌种群，但脱硫戈登氏菌 DSM 44462(T)仍然存在。这些结果强调了在处理过程中用微生物分析支持物理分析来评估细菌持久性的重要性。
