Studies on the Isolation of Aromatic Compounds Assimilating Bacteria and Its Application

• Main Authors: Cheng,Tso-Lin, 鄭作林
• Other Authors: Liu,Wen-Hsiung
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/40873651497290326056

博士 === 國立臺灣大學 === 農業化學系 === 82 === The purpose of this thesis is to investigate the biodegrada- tion kinetics of aromatic compounds and its application. Phenol degrading strain Arthrobacter oxydans 9-1, n- dodecylbenzene de- grading strain Acinetobacter calcoaceticus EBM7, toluene and ethylbenzene degrading strain Pseudomonas putida 39-1 and phen- anthrene degrading strain Cytophaga sp. A1-C, were isolated by enrichment culture from soils. The results, biodegradation kine- tic parameters, indicated that these strains were practical for the treatment of petrochemical wastewater. The metabolic inter- mediates of n-dodecylbenzene in the A.calcoaceticus EBM7 culture were identified by GC-MS as phenylacetic acid, o-hydroxyphenyl- acetic acid, 4-(o-hydroxyphenyl)-butyric acid and 4-phenyl-3- bu- tenoic acid and a metabolic pathway was proposed. Catechol-1,2-dioxygenase of P. putida 39-1 was subjected to DEAE-Sepharose CL-6B,Sephadex G-150 and Phenyl Toyopearl TSK. After these purification steps, the enzyme specific activity was increased 60-fold. This enzyme may consist of two subunits with same molecular weight. The enzyme is able to convert catechol to cis,cis-muconic acid in the presence of EDTA. A catechol accumu- lating mutant, strain MB11-7C, can accumulate catechol about to 2.3 g/L through a fermentation with succinate as co-substrate. An artificial wastewater containing 500-800 ppm phenol and 500 ppm n-dodecylbenzene could be completely degraded by the ac- tivated carbon-alginate immobilized mixed cells within 48 hrs in a sequencing batch reactor system. The variation of the bead was observed by scanning electronic microscope and found that the cells were adsorpted not only on the surface but also in the in- ternal pore structure of the activated carbon-alginate. The bio- regeneration on activated carbon was confirmed by the experiment of phenol shock loading in a packed-bed reactor.