Effects of Cellulase and Lactic Acid Bacteria on Ensiling Performance and Bacterial Community of Caragana korshinskii Silage

Abstract

The aim of this study was to evaluate the effects of cellulase (CE) and lactic acid bacteria (LAB) on Caragana korshinskii silage by analyzing the fermentation parameters, chemical composition, and bacterial community. The Caragana korshinskii was harvested at the fruiting period and treated with cellulase and LAB alone as a control treatment with no additive (CK). The ensiling performance and bacterial community were determined after 3, 7, 15, 30, and 60 days of fermentation process. Compared with the CK group, the pH, dry matter loss, and ammonia nitrogen content were significantly (p < 0.05) decreased in the LAB and CE treatments. Compared with the CK and LAB group, the contents of acid detergent fiber, neutral detergent fiber, and acid detergent lignin in the CE group decreased significantly (p < 0.05), and the water-soluble carbohydrates, acetic acid, and lactic acid concentrations increased significantly (p < 0.05). At the genus level of microorganisms, the addition of cellulase and LAB significantly reduced the microbial diversity. Compared with the CK group (78.05%), the relative abundance of Lactiplantibacillus in the CE group (90.19%) and LAB group (88.40%) significantly (p < 0.05) increased. The relative abundance of Pediococcus in the CE group (3.66%) and LAB group (2.14%) was significantly (p < 0.05) lower than that in the CK group (14.73%). Predicted functional profiling of 16S rRNA genes revealed that the addition of cellulase and LAB increased the pyruvate metabolic pathway during Caragana korshinskii silage, thereby increasing the accumulation of lactic acid concentration. The addition of cellulase expressed a better advantage in the biosynthetic capacity of lysine. In summary, the addition of cellulase and LAB could adjust the bacterial community to improve the silage quality of Caragana korshinskii, and the addition of cellulase exhibited better results than the LAB additives.

Lactic Acid Bacteria and Cellulase Improve the Fermentation Characteristics, Aerobic Stability and Rumen Degradation of Mixed Silage Prepared with Amaranth and Rice Straw

“…The pH of high-quality silage is below 4.2 [30]. After silage fermentation for 60 d, the pH of all mixed silage was less than 4.2, indicating that the mixed silage was well stored.…”

“…The growth of destructive bacteria that can produce butyric acid is suppressed by the increased production of lactic acid [30]. Feeding silage that has a high content of butyric acid increases the incidence of metabolic diseases (e.g., ketosis) in dairy cows [33].…”

“…The adequate supply of lactic acid bacteria and WSC could explain the reduction in these microbes. During the ensiling process, mixed silage inoculated with lactic acid bacteria and cellulase had the ability to produce adequate lactic acid to decrease the pH and create an acid environment, which then inhibited the reproduction of harmful microorganisms [30]. In the fermentation process of silage, the yeast, mold and coliform bacteria can produce butyric acid by secreting amino acid decarboxylases [39].…”

Enhanced lignin degradation by Irpex lacteus through expanded sterilization further improved the fermentation quality and microbial community during the silage preservation process

“…Pantoea and Methylobacterium are considered undesirable in silage and increase the fermentation and quality losses of silage (Avila and Carvalho 2020 ). Pantoea is a genus separated from Enterobacter and has parthenogenic anaerobic properties, which can compete with LAB for nutrients during silage, resulting in nutrient losses to cause butyric acid accumulation (Bai et al 2023 ; Li et al 2017 ). Methylobacterium are aerobic, Gram-negative, and facultatively methylotrophic bacteria that survive in variable environments (Kato et al 2008 ).…”

Effect of additive cellulase on fermentation quality of whole-plant corn silage ensiling by a Bacillus inoculant and dynamic microbial community analysis

“…Thus, the interaction of cellulase with LAB to improve the quality of silages has been extensively studied, and the advantages in increasing dry matter, crude protein and lactic acid contents, and decreasing acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents have been verified. The silages include fresh rice straw silage ( Sarwono et al, 2021 ), oat silage ( Xu et al, 2022 ), Caragana korshinskii silage ( Bai et al, 2023 ), mulberry leaf silage ( Lactobacillus ) ( He et al, 2019 ), a mixture of amaranth and rice straw ( Lactobacillus plantarum ) ( Mu et al, 2020 ), and mixed silage of whole-plant corn and peanut Vines ( Wang et al, 2022 ).…”