Effect of <i>Lactobacillus mucosae</i> on <i>In vitro</i> Rumen Fermentation Characteristics of Dried Brewers Grain, Methane Production and Bacterial Diversity

Abstract

The effects of Lactobacillus mucosae (L. mucosae), a potential direct fed microbial previously isolated from the rumen of Korean native goat, on the rumen fermentation profile of brewers grain were evaluated. Fermentation was conducted in serum bottles each containing 1% dry matter (DM) of the test substrate and either no L. mucosae (control), 1% 24 h broth culture of L. mucosae (T1), or 1% inoculation with the cell-free culture supernatant (T2). Each serum bottle was filled anaerobically with 100 mL of buffered rumen fluid and sealed prior to incubation for 0, 6, 12, 24, and 48 h from which fermentation parameters were monitored and the microbial diversity was evaluated. The results revealed that T1 had higher total gas production (65.00 mL) than the control (61.33 mL) and T2 (62.00 mL) (p<0.05) at 48 h. Consequently, T1 had significantly lower pH values (p<0.05) than the other groups at 48 h. Ammonia nitrogen (NH3-N), individual and total volatile fatty acids (VFA) concentration and acetate:propionate ratio were higher in T1 and T2 than the control, but T1 and T2 were comparable for these parameters. Total methane (CH4) production and carbon dioxide (CO2) were highest in T1. The percent DM and organic matter digestibilities were comparable between all groups at all times of incubation. The total bacterial population was significantly higher in T1 (p<0.05) at 24 h, but then decreased to levels comparable to the control and T2 at 48 h. The denaturing gradient gel electrophoresis profile of the total bacterial 16s rRNA showed higher similarity between T1 and T2 at 24 h and between the control and T1 at 48 h. Overall, these results suggest that addition of L. mucosae and cell-free supernatant during the in vitro fermentation of dried brewers grain increases the VFA production, but has no effect on digestibility. The addition of L. mucosae can also increase the total bacterial population, but has no significant effect on the total microbial diversity. However, inoculation of the bacterium may increase CH4 and CO2 in vitro.

Use of Lysozyme as a Feed Additive on In vitro Rumen Fermentation and Methane Emission

“…We found no effect of lysozyme on DM or OM disappearance, irrespective of incubation period is consistent with the findings of Quinn et al (2009) and Zinn et al (1997) where they observed no difference of DM and OM disappearance with the ionophores, antibiotics and sulphur supplementation in their in vitro digestion trial. This non-significant different DM and OM disappearance results are also consistent with the results observed by Soriano et al (2014), where they elicited in vitro DM and OM disappearance with Lactobacillus mucosae on dried brewers grain. The results observed in our experiment tended towards higher DM and OM disappearance, whose ultimate effect on higher in vitro total VFA production supported by Van Dung et al (2014), where they reported higher DM and OM disappearance with concentrate:roughage (8:2) substrate along with higher in vitro total VFA production.…”

Increased propionate concentration inLactobacillus mucosae-fermented wet brewers grains and duringin vitrorumen fermentation

“…The levels of gas production observed in this study were consistent with the findings reported by Soriano et al . (), who found that supplementation of L. mucosae 521129 resulted in a significant increase in the total gas after 48 h. In this study, however, significant increases in total gas production were observed after only 24 h of incubation. Elevated gas production in the grain sample containing L. mucosae 521129 might have been due to the addition of the microbes per se , which would increase the levels of microbial fermentation (Kim et al .…”

“…The increase in NH 3 ‐N concentration observed in the grain containing L. mucosae 521129, compared with that of the control, was consistent with the results obtained by Soriano et al . (). This increase indicates greater catabolism of protein and nonprotein nitrogen (Soriano et al .…”

“…This increase indicates greater catabolism of protein and nonprotein nitrogen (Soriano et al . ) and that greater amounts of nitrogen were available for microbial utilization and protein synthesis (Mamuad et al . ).…”

Survival of Lactobacillus plantarumU40 on the in vitro rumen fermentation quantified with real-time PCR

“…Increased propionic acid proportion lead to decreased methane production in the rumen because of hydrogen was used for propionic acid production. Decreased of methane by LAB inoculation reported by previous studies, with highest reduction up to 60% in cumulative methane (O'Brien et al, 2013;Chang et al, 2014;Soriano et al, 2014;Astuti et al, 2018). Methane produced by ruminant represents an energy loss for the host animal of 2-12% of dietary energy (Moss et al, 2000), therefore decreased methane production will increase energy supply for the animal, followed by increased productivity.…”