Monensin and Nisin Affect Rumen Fermentation and Microbiota Differently In Vitro

Abstract

Nisin, a bacteriocin, is a potential alternative to antibiotics to modulate rumen fermentation. However, little is known about its impacts on rumen microbes. This study evaluated the effects of nisin (1 and 5 μM) on in vitro rumen fermentation characteristics, microbiota, and select groups of rumen microbes in comparison with monensin (5 μM), one of the most commonly used ionophores in ruminants. Nisin had greater effects than monensin in inhibiting methane production and decreasing acetate/propionate ratio. Unlike monensin, nisin had no adverse effect on dry matter digestibility. Real-time PCR analysis showed that both monensin and nisin reduced the populations of total bacteria, fungi, and methanogens, while the population of protozoa was reduced only by monensin. Principal component analysis of bacterial 16S rRNA gene amplicons showed a clear separation between the microbiota shaped by monensin and by nisin. Comparative analysis also revealed a significant difference in relative abundance of some bacteria in different taxa between monensin and nisin. The different effects of monensin and nisin on microbial populations and bacterial communities are probably responsible for the discrepancy in their effects on rumen fermentation. Nisin may have advantages over monensin in modulating ruminal microbial ecology and reducing ruminant methane production without adversely affecting feed digestion, and thus it may be used as a potential alternative to monensin fed to ruminants.

Evaluation of the Effect of Four Essential Oils as Potential Alternatives for Monensin on Rumen Fermentation Characteristics and Nutrient Degradability

“…Compared with the negative control, monensin significantly enhanced propionate (P=0.001) but not acetate production. These results are in agreement with those of earlier in vitro trials (Callaway et al, 1997;Shen et al, 2017). In the rumen, propionate is generated by the succinate or acrylate pathway, and the succinate pathway is the predominant pathway (Jeyanathan et al, 2014).…”

“…A significant reduction in truly degraded organic matter (TDOM) and GP, expressed as mL/g dry matter (DM) (P=0.001) and mL/g TDOM (P=0.039), was obvious following the addition of monensin compared to that following the addition of the negative control. These results are in agreement with those of earlier in vitro trials (Callaway et al, 1997;Shen et al, 2017). The reduction in GP following monensin treatment is highly linked to its lipophilic nature, which causes a disturbance in the intracellular K + and Na + balance, which is injurious to Grampositive bacteria that produce higher amounts of hydrogen and lactate (Russell and Strobel, 1988).…”

Peer Review #2 of "Yak rumen microbial diversity at different forage growth stages of an alpine meadow on the Qinghai-Tibet Plateau (v0.1)"

“…Consistent with this, the large relative abundance of Prevotellaceae in the rumen of yak in this study indicated that these family related to the high potential carbohydrate degradation ability. Two recent studies reported that Christensenellaceae, Ruminococcaceae, Rikenellaceae, and Prevotellaceae may play important roles in forage degradation in the rumen since these groups tightly adhere to forage grass after incubation in the rumen (Liu et al 2016;Shen et al 2017). In addition, it has been reported that the abundance of Christensenellaceae is associated with changes in rumen pH (De et al 2016).…”

Distinct Effects of Bovicin HC5 and Virginiamycin on in vitro Ruminal Fermentation and Microbial Community Composition

“…Bacteriocins have been traditionally studied as potentially useful biological tools in the food industry (Deegan et al, 2006), but studies demonstrated that these antimicrobials are also effective in controlling animal pathogens (Twomey et al, 2000;Wu et al, 2007). These peptides also show synergistic interactions with antibiotics (Todorov, 2010), and could be useful to manipulate rumen fermentation (Lima et al, 2009;Shen et al, 2017 for the treatments with the addition of bovicin HC5, and might be related with changes in structure and function of the microbial community.…”

“…For decades, ruminant nutritionists have used chemical additives in rations of dairy and beef cattle to decrease dietary losses and increase useful end-products of ruminal fermentation, thus enhancing the efficiency of feed utilization (Callaway et al, 1997;Shen et al, 2017). Ionophore antibiotics are the most commonly used feed additives for manipulation of rumen fermentation in cattle (Patra, 2012).…”