Purification capability of tobacco transformed with enzymes from a methylotrophic bacterium for formaldehyde.

Plants have the ability to remediate environmental pollution. Especially, they have a high purification capability for airpollution. We have measured the purification characteristics of foliage plants for indoor airpollutants--for example, formaldehyde (HCHO), toluene, and xylene--using a tin oxide gas sensor. HCHO is an important intermediate for biological fixation of C1 compounds in methylotrophs. The ribulose monophosphate pathway of HCHO fixation is inherent in many methylotrophic bacteria, which can grow on Cl compounds. Two genes for the key enzymes, HPS and PHI, from the methylotrophic bacterium Mycobacterium gastri MB19 were introduced into tobacco. In this article, the HCHO-removal characteristic of the transformant was examined by using the gas sensor in order to evaluate quantitatively. The purification characteristics of the transformant for toluene, xylene, and styrene were also measured. The results confirmed an increase of 20% in the HCHO-removal capability. The differences of the purification capabilities for toluene, xylene, and styrene were not recognized.

Purification characteristics of golden pothos for atmospheric gasoline.

Previous studies have shown that plants have the ability to purify various atmospheric chemicals. Gasoline is one of the more serious pollutants. Soil and atmospheric pollution caused by gasoline is increasing due to the widespread use of automobiles. In this article, the purification characteristic of the pothos plant for atmospheric gasoline is investigated using a tin oxide gas sensor. The purification rate (Pr), defined as the purification ability per hour as described by a differential coefficient, has a maximum value at longer time intervals as the pollutant concentration becomes higher. Pr can be represented by an exponential function of lapsed time and its characteristic in soil is similar. A golden pothos plant growing in a 30-cm diameter pot of was placed in a 300-I experimental chamber to examine its purification ability. Pr had a maximum value 40 h after a 0.04-ml injection of gasoline into the chamber. The total purification ability (Pa) is also used in this study and is derived using the peak value (h) and the full width (tw) at half maximum of the tin oxide gas-sensor characteristic, namely Pa = h/tw x 100. The Pa of the pothos for gasoline was about 7, with the value decreasing as the pollutant concentration increased.