Environment: Wastewater. 細胞を高圧ジェットで破壊、原子間力顕微鏡で分析




詳しくはChemical Engineering Journalをご覧ください。(文責:学部4年MI)


Excess activated sludge from biological wastewater treatment units is an issue of serious concern.Bacterial cells that are major components of activated sludge can be disintegrated with several technologies, based on chemical, physical or biological methods, such as ozonation , ultrasonication , and thermophilic anaerobic sludge digestion .However, these conventional technologies face certain challenges: chemical and physical methods are costly, while biological methods have low throughput and efficiency.Hence, a technology that enables highly efficient sludge reduction accompanied by low energy consumption would be desirable.Given this challenge, a high-pressure jet device (HPJD) is a promising alternative sludge reduction technology. Our department elucidated the mechanism of bacterial cell disruption by high-pressure jet device. Escherichia coli and Bacillus subtilis, representative Gram-negative and Gram-positive bacteria respectively, were subjected to HPJD treatment followed by observation of the damaged cells with epifluorescence microscopy and atomic force microscopy (AFM), as well as spectrophotometric quantification of the released intracellular polymeric compounds.The results demonstrated that the degree of cell damage inflicted by HPJD treatment is dependent on the cell wall and membrane structure of the bacterial species.The combined methodology of AFM and spectrophotometric measurement of released polymeric substances provides a powerful approach for elucidating the cell disruption mechanisms of treatments such as HPJD, and may similarly be applied to the fields of food science and sanitary engineering where bactericidal efficiency needs to be improved.

Further reading:Chemical Engineering Journal