Effects of Different Types of LAB on Dynamic Fermentation Quality and Microbial Community of Native Grass Silage during Anaerobic Fermentation and Aerobic Exposure

Jiawei Zhang; Yichao Liu; Zhijun Wang; Jian Bao; Muqier Zhao; Qiang Si; Pengbo Sun; Gentu Ge; Yushan Jia

doi:10.3390/microorganisms11020513

Effects of Different Types of LAB on Dynamic Fermentation Quality and Microbial Community of Native Grass Silage during Anaerobic Fermentation and Aerobic Exposure

Microorganisms. 2023 Feb 17;11(2):513. doi: 10.3390/microorganisms11020513.

Authors

Jiawei Zhang^{1

2

3}, Yichao Liu^{1

2

3}, Zhijun Wang^{1

2

3}, Jian Bao^{1

2

3}, Muqier Zhao^{1

2

3}, Qiang Si^{1

2

3}, Pengbo Sun^{1

2

3}, Gentu Ge^{1

2

3}, Yushan Jia^{1

2

3}

Affiliations

¹ Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization of Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010019, China.
² Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China.
³ College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China.

Abstract

Silage of native grasses can alleviate seasonal forage supply imbalance in pastures and provide additional sources to meet forage demand. The study aimed to investigate the effects of Lactobacillus plantarum (LP), Lactobacillus buchneri (LB), and Lactobacillus plantarum in combination with Lactobacillus buchneri (PB) on the nutritional quality, fermentation quality, and microbial community of native grass silage at 2, 7, 15, and 60 days after ensiling and at 4 and 8 days after aerobic exposure. The results showed that dry matter content, crude protein content, the number of lactic acid bacteria, and lactic acid and acetic acid content increased and pH and ammonia nitrogen content decreased after lactic acid bacteria (LAB) inoculation compared with the control group (CK). LP had the lowest pH and highest lactic acid content but did not have greater aerobic stability. LB maintained a lower pH level and acetic acid remained at a higher level after aerobic exposure; aerobic bacteria, coliform bacteria, yeast, and molds all decreased in number, which effectively improved aerobic stability. The effect of the compound addition of LAB was in between the two other treatments, having higher crude protein content, lactic acid and acetic acid content, lower pH, and ammonia nitrogen content. At the phylum level, the dominant phylum changed from Proteobacteria to Firmicutes after ensiling, and at the genus level, Lactiplantibacillus and Lentilactobacillus were the dominant genera in both LAB added groups, while Limosilactobacillus was the dominant genus in the CK treatment. In conclusion, the addition of LAB can improve native grass silage quality by changing bacterial community structure. LP is beneficial to improve the fermentation quality in the ensiling stage, LB is beneficial to inhibit silage deterioration in the aerobic exposure stage, and compound LAB addition is more beneficial to be applied in native grass silage.

Keywords: aerobic stability; lactic acid bacteria; microbial community; native grass; silage.

Grants and funding

This work was supported by the program for the Technology Project of Inner Mongolia (2020GG0032) and The National Technical System of Forage Industry for Dry Grass Storage, grant number CARS-34.