Dynamic changes in fermentation profiles and bacterial community composition during sugarcane top silage...

Area of Science:

• Agricultural Science
• Microbiology
• Food Science

Background:

• Sugarcane tops are a potential silage feedstock.
• Ensilage in hot climates presents unique microbial challenges.
• Understanding bacterial dynamics is crucial for silage quality.

Purpose of the Study:

• To investigate bacterial community changes during sugarcane top silage production under hot ambient temperatures (20-35°C).
• To correlate bacterial dynamics with fermentation byproducts.
• To identify factors influencing silage fermentation in warm conditions.

Main Methods:

• Monitoring bacterial community composition over 90 days of ensilage.
• Analyzing fermentation products (acetate, propionate, butyrate, ammonia-N).
• Employing Spearman's correlation to link bacterial abundance and metabolite levels.

Main Results:

• Bacterial fermentation was initially dominated by Leuconostocaceae, followed by Lactobacillaceae, and finally a mix of Lactobacillaceae and Clostridium.
• Lactobacillaceae abundance increased significantly during fermentation.
• Clostridiaceae abundance sharply increased by day 60.
• Lactococcus and Leuconostoc showed negative correlations with fermentation acids and ammonia-N.
• Clostridiaceae and Lactobacillaceae positively correlated with acids and ammonia-N.
• High moisture content (24.31% DM) was associated with butyric acid fermentation.

Conclusions:

• Bacterial succession in sugarcane top silage under hot conditions follows a distinct pattern.
• Lactobacillaceae and Clostridiaceae play significant roles in later fermentation stages.
• High moisture content is a key factor potentially leading to undesirable butyric acid fermentation.