Effect of crystal violet dye on rumen fermentation in vitro

Crystal Violet is considered as a source of water pollution, therefore, An experiment was carried out to determine the effect of adding crystal violet (0, 3, 6, and 9 ppm) with different levels of sodium bentonite or melon peel ash (0, 4, and 8 mg as adsorbent) to a culture medium prepared from rumen fluid of sheep in a 4×2×3 factorial design. The effect of two adsorbents (0, 4, and 8 mg) on the removal of the violet crystal added to water (0, 3, 6, and 9 ppm) at 3 and 24 h incubation was also evaluated. The effective removal of dye was observed for above adsorbents (especially sodium bentonite). The gas production at 12 and 24 h, potential gas production as well as TVFA, NH3-N and all the fermentation parameters estimated from gas production including microbial protein yield, organic matter digestibility, net energy for lactation (NEl) and metabolism energy (ME) was decreased compared to control when the dye was added to media at 6 ppm (p<0.0001). The culture medium pH was not affected by the experimental treatments. By adding adsorbents (especially at 4%), most of gas production parameters and estimated parameters from gas production showed a significant decrease (p<0.0001). The overall results showed that the use of crystal violet even at low levels has a negative effect on fermentation activities of microorganisms in the media. Although two adsorbents led to a dye significant decrease in water, however they could not reduce the negative effects of dye in the media.