Improvement of fermentation quality and cellulose convertibility of Napier grass silage by inoculation of cellulolytic bacteria from Tibetan yak ( Bos grunniens )

Abstract

Aims To isolate and identify cellulolytic bacteria from yak rumen and further evaluate the effects of the isolates on the silage quality, structural carbohydrates degradation and cellulose convertibility of Napier grass silage. Methods and Results Two out of 218 strains were selected based on their most extensive transparent zone and the highest filter paper disintegration rate. The two isolates (JFL12 and JF85) could grow normally at 15–55°C, pH 3·0–7·0 and NaCl (3·0, 6·5%), and were identified as Enterococcus casseliflavus and Enterococcus faecalis by 16S rDNA sequence analysis, respectively. Napier grass was ensiled with no additive control (C), Lactobacillus plantarum (Lp), JFL12, JF85, JFL12 + Lp and JF85 + Lp for 3, 5, 7, 14, 30 and 60 days. All inoculated silages had higher lactic acid content, lower pH, ammonia nitrogen (NH3‐N) and lignocellulose contents than the control silage. Silages treated with JFL12 + Lp and JF85 + Lp had the lowest pH and NH3‐N contents, the highest lactic acid content and lignocellulose degradation among all treatments. The isolates with or without Lp significantly (P < 0·01) increased water soluble carbohydrates (WSC), glucose, fructose and sucrose contents as compared with the control silage. Silages treated with JFL12 + Lp and JF85 + Lp had higher glucose yield and cellulose convertibility than the other silages. Conclusions Therefore, the application of isolates (JFL12 and JF85) with Lp had synergistic effects on accelerating the degradation of structural carbohydrates and improving the silage quality. Significance and Impact of the Study Napier grass presents difficulty to ensiling due to its low WSC and high structural carbohydrates contents. The screened cellulolytic bacteria could be a candidate strain in improving fermentation quality and structural carbohydrates degradability of ensiled forages.

Effect of storage time on the silage quality and microbial community of mixed maize and faba bean in the Qinghai-Tibet Plateau

“…According to Yan et al (2019) , 20 g samples were evenly mixed in 180 mL reverse osmosis water, filtered with 4 layers of gauze, and the filtrate pH was determined using a glass electrode pH meter. The ammonia nitrogen (NH 3 -N) content was analyzed by the phenol-hypochlorite method ( Li et al, 2021 ). Part of the filtrate from samples was centrifuged at 12,000 rpm for 10 min and passed 0.22 μm filter before lactic acid (LA), acetic acid (AA), propionic acid (PA) and butyric acid (BA) were analyzed by high phase liquid chromatography (HPLC, KC-811, Shimadzu Co., Kyoto, Japan).…”

Dynamic changes in community structure and degradation performance of a bacterial consortium MMBC-1 during the subculturing revival reveal the potential decomposers of lignocellulose

“…Among them, the OTU18 (genus Lachnospira ), OTU54 (genus Bacillus ) and OTU43 (genus Haloimpatiens ) were also the most enriched bacteria as mentioned above. Genus Enterococcus (OTU49), which is common in the bacterial consortia from intestinal tracts of herbivores, was perceived as the promoter of lignocellulose degradation (Jin et al 2021 ; Li et al 2021 ), and the bacteria belonging to family Lachnospiraceae (OTU40) were also representative decomposers of lignocellulose (Suksong et al 2019 ), suggesting that they may be conducive to the degradation activity of MMBC-1.…”

Effects of different cutting height and nitrogen levels on the forage yield and quality of giant kinggrass (Pennisetum hybridum)

“…Bir başka ifadeyle, yemin HP oranı düşük, suda çözünebilir karbonhidrat miktarı ne kadar yüksekse, yemin pH'ı da o kadar düşük olmakta ve yemin sağlanabilirliği uzamaktadır (İptaş vd., 2009). Bunlara rağmen çalışmamızda ölçülen pH seviyeleri pek çok araştırıcı tarafından ifade edilen güvenli sınırlar içinde kalmaktadır (Geren vd., 2020;Li et al, 2020).…”