Li, Qilin2013-09-162013-09-162013-09-162013-09-162013-052013-09-16May 2013Li, Xuening. "The Impact of D-amino acids on Formation and Integrity of Biofilm – Effect of Growth Condition and Bacteria Type." (2013) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/71991">https://hdl.handle.net/1911/71991</a>.https://hdl.handle.net/1911/71991Biofouling is a major issue in applying nanofiltration and reverse osmosis technologies for wastewater treatment. Biofilm formed on the surface of membranes will severely decline the flux and cause energy waste. In this study, a novel biofouling control method that applies D-amino acids to inhibit biofilm formation was investigated. The D-amino acids previously reported to inhibit biofilm formation and disrupt existing biofilm – D-tyrosine and the mixture of D-tyrosine, D-tryptophan, D-leucine and D-methionine were tested. Pseudomonas aeruginosa and Bacillus subtilis were used as model Gram-negative and Gram-positive bacteria, respectively. D-amino acids have little effect and some effect on inhibition of biofilm formation and disruption of exiting biofilm to Pseudomonas aeruginosa, but have good effect to Bacillus subtilis. A commonly used microtiter plate assay for quantitative biofilm measurement was systematically evaluated and optimized for screening biofilm control agents. The effect of D-tyrosine on inhibition of organic fouling and P. aeruginosa biofouling on NF90 membrane surface in bench scale dead end filtration experiment was examined, which shows that D-tyrosine can effectively inhibit organic fouling and P. aeruginosa biofouling on NF90 membrane surface.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.Anti-biofoulingNF/RO membraneD-amino acidsMicrotiter plate assayThesis2013-09-16123456789/ETD-2013-05-519