The Bacteria Involved In The Metabolism Of TMAO

which was involved in the metabolism of TMAO was obtained from the epidermis and viscera of Cod. After culture of mixed flora for144 hours, the TMAO metabolism ability of the mixed flora was detected through uninhibited ion chromatography after 14h culture. The results suggested that the mixed flora from the epidermis and viscera of Cod could utilize TMAO and produced large amount of NH₄⁺ and Trimethylamine (TMA). The details for TMAO metabolism were different for the mixed floras the epidermis and viscera. For the visceral mixed flora, the concentration of TMAO, HN₄⁺ and TMA was showed as a mobile balance during the last period of fermentation, while the amount of TMAO deceased and disappeared during the fermentation for the epidermal mixed flora, and the amount of TMA inceased firstly and then decreased, and the amount of NH₄⁺ showed increasing for the whole period of fermentation. It demonstrated that there were different strain structure in epidermis and viscera of Cod. There was the bacteria which can metabolize TMA reduced from TMAO in the mixed flora from body epidermis, while for the epidermal mixed flora, there was not any kind of bacterial which could metabolize TMA.14 strains of bacteria were obtained after isolating and purifying the mixed floras from epidermis and viscera. After detecting the TMAO metabolic ability, the possible metabolic pathway for these mixed floras was analyzed in the TMAO metabolism process. For the isolated 14 strains, five strains which could metabolize TMAO were identified by 16SrDNA sequence , two strains which could metabolize TMAO stably after repeated culture and named as BP-1-1 and NZ-2. The two bacteria were identified as Stenotrophomonas maltophilia and Providencia rettgeri, by Biolog method again, which were never reported as the TMAO metabolism bacteriaThe results of TMAO utilization of BP-1-1 and NZ-2 suggested that the two strains could not utilize TMAO as the unique carbon resource or nitrogen resource. It was corresponding with the present reports. TMAO was possiblely the terminal electron receptor of electron transportation during the energy metabolism of the two strains.BP-1-1 and NZ-2 were cultured aerobicly and anaerobicly, respectively. After detecting the amount of TMAO and its metabolic products in the fermentation fluid, the results showed that TMAO reducing were not inhibited by oxygen during the growth of BP-1-1 and NZ-2. The two strains could reduce much more TMAO under the aerobic culture condition than those of anaerobic culture condition. It demonstrated that TMAO reductase in the two strains were different possibly from those from E. Coli in the previous reports. This enzyme showed higher ability under the present of oxygen, and the way of electron transportation was different from that in E.Coli in which cytochrome was used as intermediate.TMAO utilization and bacterial growth of BP-1-1 and NZ-2 under aerobic and anaerobic culture condition in 24h were analyzed and the period of TMAO reducing was identified as growth logarithmic period of BP-1-1 and NZ-2, which is consistent with the present reports.In addition, the suitable amount of BP-1-1 and NZ-2 suspension was added into the meat of fresh Cod and cultured at 4℃and room temperature constantly, respectively, while the fresh Cod meat added sterile physiological saline as control. Through sensory observation and platecount method, we found that the meat with BP-1-1 and NZ-2 suspension rotted rapidly which resulted from large of bacteria fertilization under room temperature.Comparing the results of TMAO and its metabolic products detection in the Cod meat with the control, we found that TMAO was reduced to TMA rapidly when the fish meat was infected by bacteria and the TMAOase was activated quickly in fish meat. DMA can be detected in 18h and the amount increased during the meat was spoiled. It suggested that the Cod meat could provide a good growth conditions for BP-1-1 and NZ-2. After being added into Cod meat, BP-1-1 and NZ-2 grew rapidly and resulted the meat tissues into softening and hydrolyzation, which accelerated the spoilage of fish meat. The process improved the release and activation of TMAOase from Cod tissues and the amount of DMA and FA increased rapidly in the fish tissues as a result.