Incorporation of native lactic acid bacteria as probiotics in the white shrimp culture Litopenaeus vannamei (Boone 1931) in the shrimp farm “Las Ánimas”, El Salvador

Abstract

The research was carried out in the Las Ánimas shrimp farm located in Canton Ánimas Abajo, Zacatecoluca, La Paz, El Salvador, from August 2016 to September 2017. The fundamental objective was the search for alternatives that generate a reduction of costs in the production of shrimp, as well as the improvement of environmental conditions in the study area in an efficient manner. It was carried out in two phases, the first laboratory phase, began with the collection of shrimp samples from four ponds of said farm, with the purpose of isolating native strains of Lactobacillus, obtaining 40 strains, of these four were selected, performing tests of probiotic feasibility, achieving at the end two strains that fulfilled all the requirements as probiotics, being these the lactic acid bacteria Lactobacillus paracasei (E91) and Lactococcus lactis (E33). The second was a field phase, where the probiotic was evaluated based on native lactic acid bacteria isolated against a commercial probiotic EPICIN® G2. Four treatments were configured, of which two contained the native bacteria plus the EPICIN® PST bioremediator and two with the commercial probiotic plus the EPICIN® PST, the results of the treatments formed by lactic acid bacteria plus EPICIN® PST presented a lower deterioration of water parameters, Although the waters were classified as poor according to the ICA (Water Quality Index), the native probiotics showed little variability between their constants, this data was concordant with the analysis of the Trophic Status Index (TRIX for its acronym in English), that the waters of the estuary according to this index are classified as Hypertrophic. In the productive parameters the treatments with lactic acid bacteria generated greater efficiency, since the survival for the treatments T3 and T4 is of 47.56% and 45.68%, surpassing the control treatments T1 and T2 with 44.57% and 38.97%, as well as In the survival of the ponds with native bacteria, there was greater efficiency in terms of production yield, since the T3 and T4 showed a yield of 6,806.36 kg and 5,414.55 kg, while T1 and T2 recorded a yield of 5,544.09 kg and 5,387.27 kg. At the same time, a cost benefit analysis was carried out which showed that when using the lactic acid bacteria as probiotics, a reduction in operating costs is produced, since the T3 and T4 produce an outflow of $ 62,614.63 and $ 55,481.78 against the outflows of the T1 and T2 which was $ 94,105.33 and $ 74,456.95; indicating that for T3 and T4 a return of $ 1.39 was made and $ 1.25 for each dollar invested, while the T1 and T2 were made a rebound of $ 1.10 and $ 1.15 for each dollar invested. Therefore, it is concluded that Lactococcus lactis and Lactobacillus paracasei isolated from the digestive tract of farmed shrimps are among the list of bacteria that can be used as probiotics in shrimp culture in ponds and this methodology is recommended to improve the production of shrimp farms in harmony with the environment