Evaluation of Potential Probiotic Properties of a Strain of Lactobacillus plantarum for Shrimp Farming: From Beneficial Functions to Safety Assessment

Abstract

In recent years the safety of probiotics has received increasing attention due to the possible transfer and spread of virulence factors (VFs) and antibiotic resistance genes (ARGs) among microorganisms. The safety of a strain of Lactobacillus plantarum named W2 was evaluated in phenotype and genotype in the present study. Its probiotic properties were also evaluated both in vivo and in vitro, including adherence properties, antibacterial properties and beneficial effects on the growth and immunity of Pacific white shrimp, Penaeus vannamei. Hemolysis tests, antibiotic resistance tests and whole genome sequence analysis showed that W2 had no significant virulence effects and did not carry high virulence factors. W2 was found to be sensitive to chloramphenicol, clindamycin, gentamicin, kanamycin and tetracycline, and to be resistant to ampicillin and erythromycin. Most ARGs have no transfer risk and a few have transfer risk but no significant enrichment in human-associated environments. The autoaggregation of W2 was 82.6% and the hydrophobicity was 81.0%. Coaggregation rate with Vibrio parahaemolyticus (24.9%) was significantly higher than Vibrio’s autoaggregation rate (17.8%). This suggested that W2 had adhesion potential to mucosal/intestinal surfaces and was able to attenuate the adherence of V. parahaemolyticus. In addition, several adhesion-related protein genes, including 1 S-layer protein, 1 collagen-binding protein and 9 mucus-binding proteins were identified in the W2 genome. W2 had efficiently antagonistic activity against 7 aquatic pathogenic strains. Antagonistic components analysis indicated that active antibacterial substances might be organic acids. W2 can significantly promote the growth of shrimp when supplemented with 1 × 1010 cfu/kg live cells. Levels of 7 serological immune indicators and expression levels of 12 hepatopancreatic immune-related genes were up-regulated, and the mortality of shrimp exposed to V. parahaemolyticus was significantly reduced. Based on the above, L. plantarum W2 can be applied safely as a potential probiotic to enhance the growth performance, immunity capacity and disease resistance of P. vannamei.

Characterization and selection of probiotic lactic acid bacteria from different dietary sources for development of functional foods

“…In present study examining LAB strains for hemolytic activity, 16 strains were found to be non-hemolytic, making them suitable candidates for use as probiotics. These results are consistent with the findings of previous studies by Asadi et al (2022), Das et al (2022), andWei et al (2022), who identified various non-hemolytic Lactobacillus species isolated from different dietary foods and millet-based alcoholic drinks, and Wang et al (2018), who found no evidence of probiotic hemolytic activity in lactic acid bacteria from Chinese naturally fermented non-dairy food items. Many researchers (Asadi et al, 2022;Das et al, 2022;Wei et al, 2022;Chino de la Cruz et al, 2023) have reported similar findings, indicating that probiotics do not possess hemolytic activity, which reduce their safety for use as probiotics.…”

“…Our study showed that, except BM2, all of the LAB strains tested grown at 37 • C after 24 h of incubation. The growth of LAB was limited at both 10 and 42 • C. Similar results were found in a previous investigation (Khusro et al, 2021;Wei et al, 2022;Amin et al, 2023), which supports these findings. In addition, all of our LAB isolates showed remarkable salt tolerance, even when exposed to 2% NaCl.…”

“…The presence of clear zones around colonies indicated α-hemolysis, the presence of green zones around colonies all suggested β-hemolysis and the absence of any zones surrounding colonies on the blood agar plates indicated γ-hemolysis. Strains were deemed safe only if they displayed-hemolysis (Asadi et al, 2022;Wei et al, 2022).…”

The potential role of adherence factors in probiotic function in the gastrointestinal tract of adults and pediatrics: a narrative review of experimental and human studies

“…This probiotic cntains a Cbp in its genome although the study did not attribute the probiotic property solely to the Cbp. 122 …”

Potential dsRNAs can be delivered to aquatic for defense pathogens

“…Thammasorn et al ( Thammasorn et al, 2017 ) modified L. plantarum to produce hairpin RNA by transferring genes targeting YHV specific to this probiotic and were able to enhance resistance to YHV in shrimp consuming the probiotic while retaining the original function of the probiotic, which is to inhibit the development of some diseases. Another probiotic, W2, was found to be non-toxic, containing an active bacteriostatic component, and was able to antagonize seven strains of aquatic pathogens, while also promoting shrimp growth ( Wei et al, 2022 ). W2 appears to be equally useful for RNAi control in the same manner as L. plantarum .…”