Post-Inoculation Drying and Storage Effects on HAB Viability and Nutrient Retention in Biochar

Area of Science:

• Environmental Science
• Microbiology
• Soil Science

Background:

• The impact of thermal drying on microorganisms within biochar is not well understood.
• Investigating the effects on beneficial microbes and nutrient retention is crucial for biochar applications.

Purpose of the Study:

• To determine how drying temperature affects hyper-ammonia-producing bacteria (HAB) survival in biochar.
• To assess the influence of storage on microbial recovery and nutrient stability after drying.

Main Methods:

• Biochar inoculated with HAB was dried at 40-60 °C.
• Microbial revival was assessed via reculturing after 30 days of storage.
• FTIR spectroscopy analyzed surface functional groups; nitrogen content evaluated nutrient retention.

Main Results:

• Increased drying temperatures reduced immediate microbial revival.
• Microbes showed enhanced revival after 30 days of storage.
• Drying temperature altered surface functional groups; nitrogen retention was minimally affected below 55 °C.

Conclusions:

• Drying temperature significantly influences short-term microbial survival and long-term recovery in biochar.
• Elevated temperatures may temporarily inhibit microbial activity, but recovery is possible.
• Optimizing drying is key to balancing microbial viability and nutrient retention in biochar products.