Asian Journal of Biotechnology and Bioresource Technology

Assessment of PSP Collected from Targha in Morocco Using the Luminescence of Vibrio fischeri

2026-09-21T07:23:14+00:00

Paralytic shellfish poisoning (PSP) is a public health concern caused by paralytic shellfish toxins that can accumulate in shellfish. This study assessed PSP-associated toxicity in Acanthocardia tuberculata collected from Targha on the Mediterranean coast of Morocco using a Vibrio fischeri-based Bioluminescence Inhibition Assay (BIA) and compared the result with the Mouse Bioassay (MBA). Shellfish extracts were evaluated under defined pH and dilution conditions. The influence of pH on bacterial bioluminescence was examined from pH 1 to 14, and saxitoxin (STX) concentrations of 0.16, 0.33, 0.99, and 1.65 µM were used to establish a calibration response. Complete inhibition of bioluminescence occurred at pH 1, 13, and 14, while a progressive reduction was observed at pH 2 and no substantial inhibition occurred between pH 3 and 12. Increasing STX concentrations produced progressively greater inhibition of V. fischeri bioluminescence. The MBA yielded 92.8 ± 0.1 µM STX equivalents, whereas the BIA yielded 0.40 ± 0.40 µM STX equivalents. Serial dilution of the shellfish extract generally reduced bioluminescence inhibition. The marked difference between the MBA and BIA estimates indicates that the two methods are not directly interchangeable under the evaluated conditions. Nevertheless, the BIA showed practical advantages in simplicity, rapidity, relatively low operational requirements, and avoidance of experimental animals, supporting further evaluation as a complementary screening approach for PSP surveillance.

Effect of Different Levels of Tulsi (Ocimum tenuiflorum) Leaf Powder Supplementation on the Productive Performance of Broiler Breeder Hens

2026-10-01T11:41:59+00:00

Phytogenic feed additives are increasingly examined as dietary supplements in poultry, but information on Tulsi supplementation in broiler breeder hens remains limited. This study was conducted to evaluate the effects of different levels of Tulsi (Ocimum tenuiflorum; synonym Ocimum sanctum) leaf powder supplementation on the productive performance of broiler breeder hens. A total of 120 broiler breeder hens at 40 weeks of age were randomly allotted to four treatment groups: T1 (control: basal feed without supplementation), T2 (basal feed + 0.5% Tulsi powder), T3 (basal feed + 1.0% Tulsi powder), and T4 (basal feed + 1.5% Tulsi powder), with three replicates of 10 hens each. The trial lasted six weeks (40–45 weeks of age), and body weight, body weight gain, feed intake, feed conversion ratio (FCR), feed clean-up time, egg production, and livability were recorded. At 45 weeks, T2 had the highest body weight (4646.66 g; p < 0.05), while T3 had higher hen-day egg production (79.52%) and hen-housed egg production (76.82%), lower FCR (1.09), and shorter feed clean-up time (3.22 h) at the end of the trial (p < 0.01). Cumulative livability was highest in T2 (100.00%; p < 0.05). These findings indicate that different Tulsi inclusion levels were associated with different productive responses in broiler breeder hens, with the 0.5% level associated with later body weight and livability and the 1.0% level associated with egg production, FCR, and feed clean-up time. Further studies under different breeder-management conditions are warranted.