The amounts of volatile substances responsible for the malodor of human waste (feces and urine) obtained from the storage tank of a community waste-water treatment plant were determined. Thus far, there has been little systematic research on malodor-causing substances of human waste. These substances were collected using Tenax-TA, and their concentrations were determined by the usual thermal-desorption coldtrap injector/gas chromatography/mass spectrometry (TCT/GC/MS). About 90% of the malodor-causing substances were fatty acids: acetic acid, propionic acid and butyric acid. The proportion of ammonia was 6.5%. Other malodor-causing and minor substances detected were indole, skatole, pyridine, pyrrole, hydrogen sulfide, and methyl mercaptan. In addition, a small amount of paradichlorobenzene used as a deodorizer in household toilets was also recognized.
A keratinolytic alkaline proteae (NAPase) from Nocardiopsis sp. TOA-1 degraded a scrapie prion without any chemical or physical treatment. Optimal temperature and pH were 60 degrees C and above pH 10.0. The scrapie prion was completely degraded within 3 min under optimal conditions.
Various malodorous substances generated from human feces were analyzed immediately after the use of a Western-style toilet by 50 subjects. The types and amounts of these malodorous components varied slightly between individuals, depending on the food that they had eaten and their state of health. Hydrogen sulfide was detected at concentrations of 5-26 ppb, methyl mercaptan at 2-15 ppb, ammonia at less than 100 ppb, propylaldehyde, fatty acids, and pyridine at about 10 ppb, and trimethylamine at around trace levels. When subjects had diarrhea, the amounts of fatty acids, particularly acetic acid, in feces were more than 100000-fold higher than in feces of those in normal health.
A novel alkaliphilic Nocardiopsis sp., strain TOA-1, was isolated from a tile-joint of a bathroom. Strain TOA-1 produced a variety of alkaline hydrolytic enzymes. An alkaline protease, designated NAPase, was puriˆed and characterized. NAPase had a very high keratinolytic activity and high stability under acidic conditions.
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