1. Complementarity of core functions
Water quality control
Bacillus subtilis: It can strongly decompose residual bait and feces by secreting proteases, amylases, etc., significantly reducing ammonia nitrogen (reduction of more than 50%) and nitrite (reduction of more than 60%), especially suitable for high dissolved oxygen water bodies.
Bacillus licheniformis: It is good at degrading toxic substances such as hydrogen sulfide, and has outstanding effects on the restoration of eutrophic water bodies such as old water and black water. It is also adapted to low oxygen environments and is more effective in improving bottom silt.
Disease prevention and control
Bacillus subtilis: It inhibits Vibrio and Aeromonas by secreting antimicrobial peptides such as subtilisin, while stimulating the expression of intestinal immune genes to enhance the disease resistance of shrimp.
Bacillus licheniformis: It inhibits the colonization of pathogenic bacteria by competitively occupying the intestinal mucosa, and produces substances such as butyrate to enhance the intestinal barrier function, focusing on maintaining the balance of intestinal microecology.
Growth promotion
Bacillus subtilis: It secretes highly active digestive enzymes (such as proteases and lipases), directly improving feed conversion rate, and the feed coefficient can be reduced by 18%.
Bacillus licheniformis: synthesizes B vitamins and growth factors, promotes mineral absorption, and indirectly improves shrimp meat quality and body color.
2. Synergistic application value
The combination of the two can achieve the green farming goal of "stable water quality, fewer diseases, and fast growth":
Environmental synergy: Bacillus subtilis purifies water, Bacillus licheniformis repairs the bottom, and comprehensively improves the farming environment.
Health synergy: Bacillus subtilis inhibits water pathogens, Bacillus licheniformis maintains intestinal health and reduces the incidence of diseases.
Energy synergy: combined use can further increase production (increase production by 15%~20% in white shrimp farming).
3. Precautions for use
Bacillus subtilis requires high dissolved oxygen (>5mg/L), and it is recommended to be applied in the morning on sunny days; Bacillus licheniformis tolerates low oxygen and can also be used on rainy days.
Contraindications: Bacillus subtilis is prohibited from being applied 48 hours after antibiotics; Bacillus licheniformis can be used in combination with lactic acid bacteria (with an interval of 12 hours).
Overdose risk: Bacillus subtilis is prone to hypoxia when dissolved oxygen is insufficient; Bacillus licheniformis may cause short-term fluctuations in intestinal flora.
Summary
Bacillus subtilis is the core bacteria for water purification and antibacterial and disease prevention, suitable for water adjustment in the early stage of aquaculture; Bacillus licheniformis focuses on intestinal health and bottom repair, suitable for water stabilization and intestinal protection in the middle and late stages. The alternating or combined use of the two can maximize ecological and economic benefits.