Kinetics ofLactobacillus plantarum44a in the faeces of tilapia (Oreochromis niloticus) after its intake in feed

Abstract

Aims: To study the kinetic passage of Lactobacillus plantarum 44a from feed to faeces of tilapia in order to calculate the number of Lactobacillus excreted. Methods and Results: In a single‐dose experiment, duplicate lots of 26 fish devoid of intestinal lactobacilli were fed with diets containing c. 4·5 × 1011, 6·3 × 108, 6·0 × 105 and 0 CFU of Lact. plantarum 44a per single feed ration. In the multiple‐dose experiment, duplicate lots of 30 fish each were supplied with a diet containing 1 × l011 CFU of Lact. plantarum 44a as follows: 14 times in 14 days, five times in 14 days, once in 14 days and zero times in 14 days. Faeces were periodically collected and analysed for their lactobacilli content by using a selective media. The kinetics of Lactobacillus in the faeces was described as a pulse signal defined by three parameters: θ, Ao and the time. θ, was identified as the time to reach the peak (x axis) and Ao was a constant. Ao divided by e, was identified as the height of the peak (y axis). The area below the curve Aoθ allowed the calculation of the total number of lactobacilli excreted. The ability of the mathematical model to describe the actual values was tested by a linear regression analysis. In most of the cases, the equations showed an intercept close to zero (P > 0·05) and angular coefficients near one. Conclusions: Lactobacillus plantarum 44a was excreted in short pulse signals described by a mathematical model which allowed calculating the area below the curve and consequently the survival rate. Significance and Impact of the Study: This study provides a quantitative method to study the kinetics of excretion of a probiotic bacterium in the faeces.

Probiotics use in intensive fish farming

“…The population level of lactic acid bacteria associated with the gastro intestinal tract of the fish is affected by physiological, nutritional and environmental factors related to age, food habits, season, salinity and stress. Though they are rarely present in juvenile fish reared on artificial feed but may dominate in the intestinal flora if they are supplemented in the feed (Bucio Galindo et al, 2009 (Merrifield et al, 2010c). The advantage of using Bacillus strains as a probiotic in feed is their ability to survive the pelletization process (El-Haroun et al, 2006).…”

“…Choosing a strain will depend on the fish species, rearing conditions and desired outcome of supplementation such as immuno-stimulation, disease prevention, improved growth performance to mention but few (Merrifield et al, 2010c). For successful application of probiotic strains as microbial ingredients in fish, other characteristics seem to be essential, such as high viability during processing, storage and after gastrointestinal transit (Bucio Galindo et al, 2009). Another way of administering probiotic strains could be the use of rotifers as carriers or by inoculating the rearing water with live bacteria, as the sowing of the gut with harmless bacteria may prevent infection by pathogenic bacteria (Ringo and Birkbeck, 1999).…”

“…It must not be pathogenic both to the host and to the aquatic environment and the human consumers (Merrifield et al, 2010c). A good strain must survive passage through the upper gastrointestinal tracts and reach its site of action and it must be able to function in the gut environment (Bucio Galindo et al, 2009;Giorgio et al, 2010). It must be tolerant to gastric juice and bile (Merrifield et al, 2010c;Young-Hyo et al, 2001), adhere to epithelial surfaces, persistent in the Gastro-intestinal tracts and must have immune stimulation.…”

“…Ingestion of specific strains of lactobacilli by farmed fish may have an impact on their immunity which can be a way of reducing pathogenic infections in farmed salmon and to improve health in marine fish (Bucio Galindo et al, 2009). There may however be specific strain effects.…”

“…Administration of strains such as Lactobacillus and other lactic acid bacteria to fish is generally carried out by adding viable micro-organism to the feed (Bucio Galindo et al, 2009). Choosing a strain will depend on the fish species, rearing conditions and desired outcome of supplementation such as immuno-stimulation, disease prevention, improved growth performance to mention but few (Merrifield et al, 2010c).…”