Effects of Phloroglucinol on In Vitro Methanogenesis, Rumen Fermentation, and Microbial Population Density

Abstract

This study investigated the effect of phloroglucinol (1,3,5-trihydroxybenzene) supplementation alone on methane production, rumen fermentation profiles, and microbial population structure of mixed in vitro cultures. Treatments included a control group containing a substrate with no supplement, and substrates supplemented with 2, 4, 6, 8, or 10 mmol/L of phloroglucinol. The results revealed that phloroglucinol was able to decrease methane production in a dose-dependent manner. The highest decrease was observed with 8 and 10 mmol/L supplementations. The relative quantity of methanogen was not affected by phloroglucinol, whereas genus Coprococcus was increased with increasing concentrations of phloroglucinol (p<0.05). Total gas production, dry matter digestibility (DMD), and NH 3-N were significantly lowered by phloroglucinol (p<0.001). Total short-chain fatty acid (SCFA) concentration was not affected by phloroglucinol. Acetate proportion increased with the addition of phloroglucinol at the expense of propionate (p<0.001). This might indicate the redirection of [H] from methane to acetate, and might be related to methane inhibition.. Our study concluded that supplementation of phloroglucinol alone could decrease methane production by inhibiting nutrient digestibility in the rumen and by possible redirection of rumen fermentation to acetate production. Genus Coprococcus could be an important actor for phloroglucinol metabolism in the rumen.

The effects of heat-moisture treatment on resistant starch levels in cassava and on fermentation, methanogenesis, and microbial populations in ruminants

“…Gas production calculations using equations from López et al . [ 18 ] identified reductions in maximum gas production (B), but gas production rates (k) and time lags (L) were significantly increased (p < 0.05) by HMT. Methane concentrations were affected during initial 12 h incubations (p < 0.01), but gas production at 24 h–48 h showed no significant effects.…”

“…This phenomenon was related to methanogen populations, which were not significantly affected by HMT treatment and increased acetate production. The CH 4 production in the rumen can be affected directly by methanogen population or indirectly by nutrient digestion [ 18 ]. In this study, HMT increase acetate concentration in the rumen.…”

“…The relative quantification method used was comparative 2 −ΔΔCT method according to Schmittgen and Livak [ 17 ]. Specific primers of the target group and the amount used for real-time PCR are listed in Table-1 [ 18 ]. In the calculation of 2 −ΔΔCT value, C T of total bacteria were used as an endogenous control.…”

“…Heatmoisture treatment increased gas production at 2 h, 4 h, and 6 h. HMT2 recorded the highest gas production at 2 h, while HMT1 had the highest gas production at 4 h and 6 h. However, at 24 h-48 h, significant decreases in gas production were recorded (p < 0.05), with the lowest decline at HMT2. Gas production calculations using equations from López et al [18] identified reductions in maximum gas production (B), but gas production rates (k) and time lags (L) were significantly increased (p < 0.05) by HMT. Methane Rumen fermentation profiles were affected by HMT (Table -6).…”

The effect of silkworms (Bombyx mori) chitosan on rumen fermentation, methanogenesis, and microbial population in vitro

“…Chitosan from CHIJC02 exhibited both direct and indirect effects on methanogenesis inhibition, as evidenced in the decrease of methanogen population and the limitation of substrate availability and changes in microbial community composition resulting in reduced CH 4 production [ 49 ]. It was observed that chitosan can reduce the methanogen population in the CHIJC02 treatment.…”