Effects of Acremonium cellulase and heat-resistant lactic acid bacteria on lignocellulose degradation, fermentation quality, and microbial community structure of hybrid elephant grass silage in humid and hot areas

Abstract

To better evaluate the effects of Acremonium cellulase (AC) and previously screened heat-resistant Lactobacillus plantarum 149 (LP149) on lignocellulose degradation, fermentation quality, and microbial community during ensiling in humid and hot areas, this study used a small-scale fermentation system to prepare hybrid elephant grass silage at 30 and 45°C, respectively. Compared to control and commercial inoculant Lactobacillus plantarum (LP), the addition of AC or strain LP149 decreased the contents of neutral detergent fiber, acid detergent fiber, and cellulose and increased the contents of glucose, fructose, and sucrose during fermentation. Furthermore, AC and LP149 treatments altered the microbial communities' structure during ensiling. AC treatment provided more substrate for microbial fermentation, resulting in an increase in bacterial alpha diversity. LP149 treatment increased the Lactobacillus abundance and optimized the bacterial community compositions. In addition, AC and LP149 treatments had higher (P < 0.05) lactic acid and acetic acid contents and lower (P < 0.05) pH, butyric acid, and NH3-N levels compared to the control. These results indicated that AC and strain LP149 are promising silage additives that can promote lignocellulose degradation and improve the fermentation quality of hybrid elephant grass in humid and hot areas.

Influence of Genotype and Anaerobic Fermentation on In Vitro Rumen Fermentation Characteristics and Greenhouse Gas Production of Whole-Plant Maize

“…However, due to the structural complexity of the fibrous carbohydrates of the fresh WPM, the rate of total gas (TG) production was lower compared to the fermented WPM. Other studies have indicated that during the aerobic fermentation of WPM, the complexity of fibrous carbohydrates decreases due to the changes that occur in their structure [33], which favors the adhesion and colonization of the feed by ruminal microbes [34] and allows us to assume that it was the reason why the rate of TG production was higher in the fermented WPM. In addition, the TG production also indirectly reflects the degradability of the feed and is dependent on the chemical composition, especially carbohydrates and proteins [35,36].…”