| Autor: |
Douwes, A C, Van Der Burg, G J, Schouten, N, Kneepkens, C M F |
| Zdroj: |
Pediatric Research; October 1986, Vol. 20 Issue: 10 p1063-1063, 1p |
| Abstrakt: |
The relationship between hydrogen (H2) and methane (CH4) production by colonic flora remains unclear, though it has been suggested that CH4 is produced at the expense of H2 and carbon dioxyde (CO2). We developed an anaerobic incubation procedure to examine this relationship in vitro. The .system consists of a perspex cylinder to prepare buffered faecal suspensions, and glass tubes for incubation with glucose and lactulose, connected by a closed circuit and freed from air by nitrogen flow. Afte ≥ 1 h incubation H2, CH4 and oxygen (O2) are estimated by gas chromatography. All incubations are performed in duplicate. Numbers of viable bacteria before and after incubation were estimated by standard procedures. Results. In 96 duplicate incubations with faeces from healthy subjects, H2 ranged from 577 to 28,478 ppm (blanks 1-1441 ppm); mean coefficient of variation 9,8%. In 62/69 incubations CH4 was detected ranging from 2 to 4509 ppm (blanks 1-1880 ppm); mean coefficient of variation 13%. O2 was <½% in all samples. Logcounts of viable aerobic and anaerobic bacteria in faeces before and after incubation did not differ after correction for dilution. CH4 appears to be producerd at a slower rate than H2. On prolonged incubation (24 h), H2 concentration decreases while CH4 production continues, and a high molecular gaseous compound appears after 6 h. CH4 production is not enhanced by addition of H2 and CO2. Conclusion: CH4 is not derived from H2. Disappearance of H2 seems to be related to formation of an unknown high molecular compound. |
| Databáze: |
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