Bacillus licheniformis

Introduction

Bacillus licheniformis is a thermophilic, spore-forming bacterium used to accelerate the breakdown of organic materials during the active, high-temperature phase of composting. It is particularly efficient at degrading proteinaceous and fibrous substrates such as poultry manure, sugar press mud, and kitchen waste. Its heat resistance and enzyme production make it a critical microbe in the first wave of microbial decomposers.

Scientific Description

Bacillus licheniformis is a gram-positive, rod-shaped, facultatively anaerobic bacterium from the family Bacillaceae. It thrives in the thermophilic range (40–60°C) and is known for secreting industrial-grade enzymes such as proteases, amylases, cellulases, and xylanases. It is naturally found in compost heaps, decaying plant matter, soil, and manure-rich environments.

Key characteristics:

• Thermophilic Activity: Functions optimally at 50–55°C, ideal for peak composting conditions.
• High Enzyme Yield: Breaks down complex organic matter into simpler compounds rapidly.
• Spore-Forming: Survives harsh composting conditions (dryness, heat, nutrient fluctuations).
• Pathogen Control: Competes with and suppresses foul-smelling or disease-causing bacteria during decomposition.

Benefits

• Accelerates High-Temperature Decomposition: Works early in composting to break down proteins, carbohydrates, and fibers.
• Controls Putrefaction and Odor: Inhibits anaerobic bacteria responsible for offensive smells.
• Reduces Composting Time: Speeds up thermophilic phase and transitions compost faster to curing.
• Improves Nutrient Availability: Helps convert nitrogen and carbon into more plant-available forms.
• Enhances Microbial Succession: Prepares compost for colonization by curing-stage microbes (e.g., Pseudomonas, Trichoderma).

Uses

• Waste Types: Poultry litter, press mud, food waste, hotel/canteen waste, vegetable market waste, sugarcane trash, banana waste.
• Application Methods:
  • Compost starter inoculant: 1–2 kg (dry) or 1–2 L (liquid) per ton of raw material
  • Layering method: Add during pile formation with alternating green/brown waste layers
  • Moisture control: Functions well at 50–65% moisture — avoid drying during thermophilic phase
• Ideal Composting Conditions: Temperature 45–60°C, well-aerated piles, C:N ratio between 25–30

Trivia

• Used industrially to produce thermostable enzymes, many of which are also applied in detergents and leather processing.
• Its proteolytic enzymes are particularly good at composting high-protein inputs like meat scraps and poultry manure.
• Inoculated compost piles often heat up faster due to its aggressive metabolism.
• When combined with Bacillus subtilis or Phanerochaete, the compost balance improves significantly across protein, cellulose, and lignin degradation.