猪粪便细菌群作用下3-甲基吲哚(粪臭素)和吲哚形成的研究

Effect of Mixed Population of Pig Fecal Bacteria on 3-Methylindole (skatole) and Indole Production

本试验研究了猪粪便菌群作用下粪臭素 (3 甲基吲哚 )和吲哚的形成途径以及pH对色氨酸降解成粪臭素和吲哚相对产量的影响。试验结果表明 ,在猪大肠菌群作用下L 色氨酸既能直接降解形成吲哚 ,又能经吲哚 3 乙酸再形成粪臭素。pH对色氨酸降解成粪臭素和吲哚相对产量有明显影响。pH =6 .5时 ,约 4 2 %色氨酸转化为粪臭素 ,5 8%色氨酸转化为吲哚 ;pH =8.0时 ,约 78%色氨酸转化粪自素 ,2 2 %氨酸转化为吲哚 ;pH =5 .0时 ,只有 16 %色氨酸转化为粪臭素 ,而 84 %色氨酸转化为为吲哚。本试验结果提示 ,通过改变环境的pH可以使色氨酸降解成粪臭素和吲哚相对产量发生变化 ,高pH环境有利于粪臭素的产生 ,而低pH环境有利于吲哚的产生。

An in vitro study was conducted to investigate the formation of indole and 3 methylindole(skatole) by a mixed bacterial populations from the large intestine of pigs and to study the effects of pH on the relative production of indole and skatole. Pig fecal slurries converted added L tryptophan either to indole without detectable intermediate or to 3 methylindole(skatole) via indole 3 acetate. The pH had dramatic effects on the relative production of skatole and indole. At pH 6.5,42% of the L tryptophan was converted to skatole and 58% was converted to indole after 24 h of incubation. At pH8.0, 78% of the added L tryptophan was converted to skatole and 22% was converted to indole. While at pH 5.0, only 16% of the added L tryptophan was converted to skatole and 84% was converted to indole. Our results show that the relative amounts of the two end products can be altered by changing the environmental conditions. High pH values favor the production of skatole, while low pH values favor the production of indole.