Diversity of bacterial community during ensiling and subsequent exposure to air in whole-plant maize silage

Abstract

ObjectiveTo describe in-depth sequencing, the bacterial community diversity and its succession during ensiling of whole-plant maize and subsequent exposure to air.MethodsThe microbial community dynamics of fermented whole-plant maize for 60 days (sampled on day 5, 10, 20, 40, 60) and subsequent aerobic exposure (sampled on day 63 after exposure to air for 3 days) were explored using Illumina Miseq sequence platform.ResultsA total of 227,220 effective reads were obtained. At the genus level, there were 12 genera with relative abundance >1%, Lactobacillus, Klebsiella, Sporolactobacillus, Norank-c-cyanobacteria, Pantoea, Pediococcus, Rahnella, Sphingomonas, Serratia, Chryseobacterium, Sphingobacterium, and Lactococcus. Lactobacillus consistently dominated the bacterial communities with relative abundance from 49.56% to 64.17% during the ensiling process. Klebsiella was also an important succession bacterium with a decrease tendency from 15.20% to 6.41% during the ensiling process. The genus Sporolactobacillus appeared in late-ensiling stages with 7.70% abundance on day 40 and 5.32% on day 60. After aerobic exposure, the Lactobacillus decreased its abundance from 63.2% on day 60 to 45.03% on d 63, and Klebsiella from 5.51% to 5.64%, while Sporolactobacillus greatly increased its abundance to 28.15%. These bacterial genera belong to 5 phyla: Firmicutes (relative abundance: 56.38% to 78.43%) was dominant, others were Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria. The bacterial communities clearly clustered into early-ensiling (d 5), medium-ensiling (d 10, d 20), late-ensiling (d 40, d 60), and aerobic exposure (d 63) clusters, with early- and late-ensiling communities more like each other than to the aerobic exposure communities.ConclusionHigh-throughput sequencing based on 16S rRNA genes proved to be a useful method to explore bacterial communities of silage. The results indicated that the bacterial communities varied during fermentation and more dramatically during aerobic exposure. The study is valuable for understanding the mechanism of population change and the relationship between bacteria and ensilage characteristics.

Trends in designing microbial silage quality by biotechnological methods using lactic acid bacteria inoculants: a minireview

“…dominated during the ensiling process. The results of those papers provided valuable information for the further development and application of bacteria in silage, although the underlying relationship between dynamic patterns of silage microbiota and the outcome of fermentation needs further extensive studies (Zhou et al 2016 ; Hu et al 2018 ; Ogunade et al 2018 ).…”

Silage fermentation—updates focusing on the performance of micro‐organisms

“…Propionic acid bacteria (PAB), enterobacteria and others species found in different silagesHu et al (2018) in young bovines (calves)(Goossens et al 2017) and haemorrhagic bowel syndrome, a disease reported to be high in dairy cows(Elhanafy et al 2013).The main aerobic spore-forming bacteria (ASFB) species in silage belong to the genus Bacillus (B. licheniformis,B. pumilus, B. coagulans, B. sphaericus, B. cereus, B. polymyxa)(Pahlow et al 2003;Driehuis et al 2018) …”

The Bacterial Community Associated with the Amarillo Zamorano Maize (Zea mays) Landrace Silage Process

“…Mainly in AS, members of Lactobacillus genera were dominant in the fermentation process, with a variable RA of other Firmicutes, Proteobacteria, and Bacteroidetes. But in AZS, Enterobacteriaceae OTUs had higher relative abundance during the fermentation process than all the Firmicutes and Bacteroidetes, as was reported in whole-plant maize silage from China [ 36 ]. Although Enterobacteriaceae species were the main competitors of LAB for the sugars in the silage, strains of Citrobacter , Morganella , Plesiomonas , Serratia , Enterobacter , Erwinia , Klebsiella , Morganella , and also from the undefined enterobacteria genera, could play key roles in different stages of the silage process.…”

“…Although several bacterial species have been isolated and characterized by the following method: 16S ribosomal RNA (16S rRNA) gene, massive next-generation sequencing (NGS) studies on the silages of alfalfa, grasses, small grains, maize, maize-sorghum, and soybean have provided a larger view on silage microbial community and dynamics [ 21 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Specifically, in maize silages, NGS studies have also shown the effects of additives or silage size on the bacterial community and silage quality of maize hybrids or corn stover [ 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. However, there are no NGS studies on the composition, diversity, and succession of the bacterial communities associated with Mexican fodder maize landraces.…”