Introduction
Effective microbial control in hatcheries is essential for achieving predictable and consistent outcomes. In production facilities, proactive microbial management, robust biosecurity measures, and thorough cleaning and disinfection protocols create a controlled environment that minimizes the risks of opportunistic bacteria entering or dominating the system.
Our study focuses on microbial management in the live food sector using EG SEP-Art® D-FENSE and a CIP (clean-in-place) agent to enhance biosecurity in the Artemia sector. The CIP agent is used initially to remove bacterial biofilm, reducing the microbial population in the tank. This step aids D-FENSE technology in controlling bacterial growth in the hatching and enrichment tank, ensuring consistent production of high-quality live food both nutritionally and microbially.
Materials and methods
Artemia cysts were hatched for 20 hours at a temperature of 28±1°C , and a salinity of 38ppt . The pH of the hatching medium was maintained above 8.2 during the complete hatching cycle using 120ppm of NaOH (30%) as needed . Two treatments were tested:
After hatching, Artemia nauplii were harvested, rinsed, and restocked for 22-hour enrichment using Easy DRY SELCO (INVE Aquaculture, Belgium) in two 360 ppm doses, one at the start and another after 10 hours. Temperature was maintained at 27±1°C, pH above 7.5 with 0.5 g.L-1 bicarbonate initially and 120 ppm NaOH as needed. Dissolved oxygen was kept above 100% using pure oxygen . Three treatments were tested:
The microbial quality of the hatching and enrichment medium was assessed using traditional plating methods on TSA (1.5% salt) and TCBS agar. Water samples were filtered to remove nauplii. The treatment’s effect on the enrichment process was evaluated by FAME (Fatty Acid Methyl Ester) analysis of the nauplii at the trial’s end.
Results
Using EG SEP-Art® D-FENSE cysts significantly enhances the efficient production of high-quality live food. Results showed a 3-log reduction in total bacterial load and a 4-log reduction in Vibrio load in the hatching medium 24 hours post-hatching.
The use of EG SEP-Art® D-FENSE cysts during hatching, combined with the application of the CIP agent during traditional enrichment practices (Tr B) , resulted in a 3-log reduction in both Vibrio and total bacterial load compared to the control treatment (Tr A).
In the all-in-one enrichment procedure, bacterial levels remained similar to Tr B, indicating that EG SEP-Art® D-FENSE with the CIP agent effectively controls microbial development (Figure 1). This method eliminates the labor-intensive step of harvesting and cleaning from traditional practices.
Enhancing water quality with the CIP agent significantly improved enriched Artemia nauplii. HUFA content increased by 60% in Tr B and 30% in Tr C compared to Tr A (Figure 2). Lower bacterial levels likely reduce HUFA utilization and conversion. Improved water quality correlates with increased vitality, better water filtration, and enhanced nutrient uptake, thereby enhancing nutritional value.
Conclusions
These results demonstrate the effectiveness of combining EG SEP-Art® D-FENSE with the selected CIP agent in improving the microbiological and nutritional quality of Artemia. The study highlights the importance of strong biosecurity measures to enhance and standardize live food production.
Using EG SEP-Art® D-FENSE cysts with CIP agents (all-in-one treatment) streamlines hatchery operations by eliminating the intermediate harvest and rinsing step, reducing labor while maintaining high nutritional and microbial quality standards.