Effect of a diet enriched with sodium propionate on growth performance, antioxidant property, innate-adaptive immune response, and growth-related genes expression in critically endangered beluga sturgeon (Huso huso).

Organic acids are active substances required for improving the productivity and wellbeing of aquatic animals. Herein, the study investigated the effects of sodium propionate on growth performance, antioxidative and immune responses, and growth-related genes expression in beluga sturgeon (Huso huso). For eight weeks, fish fed sodium propionate at 0, 1.2, 2.5, and 5 g kg-1. The final weight, weight gain, and SGR were substantially increased while FCR decreased by dietary sodium propionate at 2.5 and 5 g kg-1 (P < 0.05). The expression of Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) was markedly upregulated (P < 0.05) by dietary sodium propionate in the gills and livers of beluga. The highest mRNA level of GH and IGF-1 has been observed in fish fed a 2.5 g sodium propionate/kg diet. The red blood cells count, and hemoglobin level were meaningfully increased (P < 0.05) by 2.5 and 5 g sodium propionate/kg diet compared with 0 and 1.2 g kg-1 levels. Further, the hematocrit level was increased (P < 0.05) by a dietary 5 g sodium propionate/kg diet. The total protein level and lysozyme activity were meaningfully increased (P < 0.05) by 2.5 and 5 g sodium propionate/kg diet compared with 0 and 1.2 g kg-1 levels. The highest superoxide dismutase was observed in fish fed 2.5 g sodium propionate/kg diet. Catalase activity was significantly higher in fish fed 5 g kg-1 than 1.2 g kg-1. The glutathione peroxidase activity was markedly higher in fish fed 2.5, and 5 g kg-1 than fish fed control diet. The lowest malondialdehyde levels were observed in fish fed 1.2, and 2.5 g sodium propionate/kg diets. Moreover, the highest mucosal total protein, total immunoglobulin and lysozyme were recorded in fish fed 2.5, and 5 g sodium propionate/kg diets. The obtained results indicate that dietary sodium propionate is recommended at 2.5-5 g kg-1 to improve beluga sturgeon's growth performance, feed utilization, and wellbeing.

Bioremediation of Crude Oil Using Bacterium from the Coastal Sediments of Kish Island, Iran.

BACKGROUND: Much of the environment is affected by petroleum contamination. It imposes serious health problems for humans as well as serious environmental impact. Bioremediation is an important consideration for removing environmental pollutants because, compared with other technologies, it incurrs lower costs and is environmentally compatible. METHODS: Crude oil degrading bacteria were isolated using serial dilutions of a bacterial consortium. The Taguchi experimental design L16 (4(5)) was used to optimize the biodegradation process of crude oil by the isolated strain. This investigation applied the parameters of temperature, salinity, pH, NH4Cl and FeSO4.7H2O. Modeling the kinetics of crude oil biodegradation included five batch cultivation experiments (2.5 ml/L to 40 ml/L) using crude oil as a single limiting substrate. RESULTS: Halomonas sp. MS1 was identified using identification tests. Maximum biodegradation efficiency was predicted to occur at pH=9, temperature=30 °C, salinity=2%, NH4Cl concentration=0.4 g/L and FeSO4.7H2O=0.04 g/L. After optimization, biodagradation was significantly (P<0.05) higher (i.e. 90.65%) than it results under the original conditions. Furthermore, growth kinetics modelling of bacteria in various concentrations of crude oil showed a positive correlation between increased concentration, up to 10 ml/L and bacterial growth, but this was not evident at higher concentrations (20-40 mL/L). CONCLUSION: Overall, bacteria in surface sediment samples from Kish Island have been determined as having good potential for application in oil biodegradation. Optimum amounts of the studied factors were determined successfully by applying the Taguchi experimental design and the models of Teissier and Haldane are suggested as kinetic models to describe the batch crude oil degradation behavior of MS1.