cee200: Environmental and Water Resources Engineering Seminar

UCLA Civil & Environmental Engineering Department
Response and Recovery of Microbial Communities Subjected to Oxidative Treatment Train of 1,4-Dioxane Contaminant Mixtures

Yu (Rain) Miao
Doctoral Candidate

Civil and Environmental Engineering Department, UCLA
The effects of novel combined oxidation and biodegradation strategies on soil microbial community was studied, of a mixture with different levels of 1,4-dioxane and chlorinated volatile organic compounds (CVOCs). Oxidation by hydrogen peroxide (H2O2) produced ~80% elimination of 1,4-dioxane regardless of the initial concentrations, while was inhibited partly by the high level of CVOCs, and bioaugmented Pseudonocardia dioxanivoransCB1190 (CB1190)made the significant function in biodegradation phase. The microbial populations were affected negatively during oxidation phase, with a sign of diminution in biodiversity, richness and biomarker genes, while the recovery of the cultivable microbiomes and a more diverse community were obtained during the post-oxidation biodegradation phase. The Illumina Miseq platform and bioinformatics analysis were used to find out a general oxidative tolerant genus Ralstonia, and genera Cupriavidus, Pseudolabrys, Sphingomonas were identified as dominance after biodegradation. The bioaugmented CB1190 was outcompeted with the community evolution, and only found co-occurred with a few genera (i.e., Cupriavidus).The multidimensional analysis elucidated the separation of microbial populations along with time under all conditions, suggesting the chronical succession as determining factor that independent to 1,4-dioxane and CVOCs mixtures. The network analysis highlighted the interspecies competition and dynamics of microbiomes during the biodegradation phase, in line with the shift of predominant genera along with the treatment train. Combined, this study revealed promising 1,4-dioxane removals by using bioaugmentation in the combined oxidation-biodegradation treatment train, and enhanced our understanding of microbial mechanisms behind the treatment train, that may help practitioners who implement this technology to predict the microbial community state after achieving removal goals.

Where: 4275 Boelter Hall
When: 11am – 12pm, Thursday, April 19

Yu (Rain) Miao is a PhD student in Dr. Shaily Mahendra’s laboratory at UCLA. He earned his MS degree from Nanjing University, China. His research interests include next-generation sequencing and molecular biotechnologies in diverse environments. He has published five papers as first-author focused on microbial community analysis of water and soil treatment processes.