Aims: The objective of this study was to investigate the effect of temperature (5-25°C) on epiphytic lactic acid bacteria (LAB) populations during 60 days of fermentation of whole-plant corn silage.
Methods and results: Vacuum bag mini-silos of chopped whole-plant corn were incubated at five different temperatures (5, 10, 15, 20 and 25°C), according to a completely randomized design with four repetitions. The silos were opened and sampled on day 0, 1, 2, 3, 7, 28 and 60. At 20 and 25°C, Lactobacillus plantarum- and Pediococcus pentosaceus-related operational taxonomic units (OTU) dominated the fermentation within 1 day. After 7 days, the OTU related to the heterofermentative species Lactobacillus buchneri began to appear and it eventually dominated silages incubated at these temperatures. Population dynamic of LAB at 5 and 10°C was different. At these temperatures, Leuconostoc citreum OTU was identified at the beginning of the fermentation. Thereafter, Lactobacillus sakei- and Lactobacillus curvatus-related OTU appeared and quickly prevailed. Corn silage at 15°C acted as a transition between 20-25°C and 5-10°C, in terms of LAB diversity and succession.
Conclusion: The conditions of silage incubation temperature affect species diversity of LAB population with notable difference along the temperature gradient. Colder temperature conditions (5 and 10°C) have led to the identification of LAB species never observed in corn silage.
Significance and impact of the study: This study demonstrated the impact of temperature gradient on the diversity and some important population shift of lactic acid bacteria communities during fermentation of corn silage.
Keywords: cold climate; denaturing gradient gel electrophoresis; inoculant; lactic acid bacteria; microbial succession; temperature gradient.
© 2016 The Society for Applied Microbiology.