Preliminary screening of microplastic contamination in different marine fish species of Taif market, Saudi Arabia.

Microplastics (MPs), as a physical anthropogenic contaminant, represent a serious, human health concern due to their toxicity and ability to act as vectors for other pollutants and pathogens. This study aimed to screen for MP contamination in marine fish in Taif market, Saudi Arabia. A total of 22 fish species were used according to their different marine habitats and feedings. We have focused on extracting MPs from gills and muscles using KOH digestion. Nile red dye was used for the MP identification under fluorescence microscopy followed by the Fourier-transform infrared spectroscopy analysis. This study has reported MP contamination in gills and muscles of all the studied fish, in which poly(vinyl butyral) (PVB) was present in epipelagic species, poly(vinylidene fluoride) (PVDF) and poly(2,4,6,-tribromostyrene) (PtBS) were present in pelagic species, and PtBS and chlorosulfonated polyethylene were present in demersal/benthopelagic species. Moreover, benthic fish samples contain PtBS particles; reef-associated species have three different MP particles/fiber PtBS, PVDF, and poly(vinyl formal) and the rest of the studied species samples contain PtBS. The results highlight that the MP pollution increased to reach different species from the pelagic species to the benthic ones. PtBS as a type of polystyrene was the most dominant MP found in most species.

Investigating microplastics and potentially toxic elements contamination in canned Tuna, Salmon, and Sardine fishes from Taif markets, KSA.

Microplastics (MPs) have been documented in different foodstuffs and beverages, that could affect human health due to their ingestion. Furthermore, seafood contamination with MPs puts pillars of food availability and utilization at risk. The present study investigates MPs and toxic elements pollution in commercially canned fishes from Taif governorate markets. Seven different canned fishes' brands were used in the present study from different manufacturer countries and purchased from Taif markets. Tissue samples were digested by 10% of KOH; then, dry filters were analyzed by Fourier-transform infrared spectroscopy to detect MPs. Filtrates were used to detect any potentially toxic elements by inductively coupled plasma. Different MPs were detected in edible tissue, such as canned Tuna contaminated with nylon, 1,2-polybutadiene, and ethylene vinyl alcohol. Sardines contain ethylene vinyl alcohol and poly(vinyl stearate), but Salmon does not have any MPs. Different elements were present in the selected samples in the decreasing order of Al > Se > Zn and traces of As and Sb. Canned fishes were contaminated with MPs and potentially toxic elements. This contamination could be a warning of the potential health risks with the long-term exposure. Therefore, it is recommended to include micro-, meso-, and even nanoplastics in the guidelines of testing food safety management systems.

Micrococcus luteus and Pseudomonas species as probiotics for promoting the growth performance and health of Nile tilapia, Oreochromis niloticus.

Micrococcus luteus and Pseudomonas species were isolated from the gonads and intestine of Nile tilapia, Oreochromis niloticus. M. luteus and Ps. species antagonized Aeromonas hydrophila with inhibition zone of 4 and 9 cm diameter, respectively. Both microorganisms were added to artificial basal diet with 30% crude protein to evaluate their efficacy on the growth-performance and survival rate, besides some blood-parameters and chemistry. Two hundred and forty O. niloticus with average body-weight of 2.35 +/- 0.1 g/fish were equally divided into four treatments of triplet replicates. T(1) was given basal diet (control), T(2) was given basal diet with M. luteus, T(3) was given basal diet with Ps. species, T(4) was given basal diet with both M. luteus and Ps. Species. Fishes were fed twice daily at the rate of 3% of their live body-weight, for six days a week during the experimental periods (90 day). Fish were challenged by A. hydrophila (0.3 x 10(7) cells ml(-1)) via intra-peritoneal injection and kept for 14 more days. The best growth rate, feed utilization and survival rate were noticed with T(2). The erythrocyte-count was significantly higher with T(2) than T(3) than the control T(1). The hematocrit-values (HCT) and hemoglobin-content (Hb) were significantly decreased with T(3) and T(4). The highest glucose-level was recorded with T(3). The challenged fish of T(2) showed 25% mortality, while T(1), T(3) and T(4) showed 80-90% mortality. M. luteus enhanced the fish growth and health. It is recommended to use M. luteus as a probiotic in vivo, while Pseudomonas species showed probiotic effects in vitro only.