In an era of rising population density and industrialization, the environment confronts growing challenges. Soil, agricultural land, and water bodies are becoming increasingly polluted by petroleum waste and hydrocarbons. While hydrocarbons are naturally present in crude oil, refining processes compound the complexity and toxicity of hydrocarbons. This is particularly evident in polycyclic aromatic hydrocarbons (PAHs) found in the air and soil, known for their carcinogenic, mutagenic, and teratogenic properties. In response, biodegradation emerges as an eco-friendly, cost-effective solution, especially in petroleum-contaminated settings. Biodiverse microbial communities play a pivotal role in managing hydrocarbon contamination, contingent on location, toxicity, and microbial activity. To optimize biodegradation, understanding its mechanisms is essential. This review delves into varied bioremediation techniques, degradation pathways, and the contributions of microbial activities to efficiently removing hydrocarbon pollutants. Recent research spotlights specific microorganisms like bacteria, microalgae, and fungi adept at hydrocarbon degradation, offering a contemporary perspective on petroleum hydrocarbon pollutant bioremediation. These microorganisms efficiently break down petroleum hydrocarbons, with enzymatic catalysis markedly accelerating pollutant breakdown compared to conventional methods. Given the intricate nature of hydrocarbon contamination, cooperative bacterial consortia are instrumental in effective cleanup, driven by specific genes guiding bacterial metabolism. For cost-effective and efficient removal from compromised environments, it is advisable to adopt an integrated approach that combines biostimulation and bioaugmentation.

This research examined the role of nano curcumin (NC) on growth performances, body composition, and blood parameters of red tilapia (Oreochromis sp.) challenged with Aspergillus flavus. Fish (5.0 g ± 0.30) were randomly distributed in four equal groups (20 fish per pond in triplicates) and fed various concentrations of NC fortified with 0 (Control), 40 mg/kg (NC1), 50 mg/kg (NC2), and 60 mg/kg diet (NC3) of nano curcumin. After eight weeks of the feeding trial, the fish were challenged with A. flavus for 15 days, and the cumulative mortality was recorded. Fish fed with different concentrations of NC improved significantly (p < 0.05) the growth performances, feed utilization, and survival rate. There was no significant (p > 0.05) difference between NC2 and NC3 treatments. However, NC3 exhibited higher performances. Fish feed supplemented with NC decreased the mortality rate when challenged with A. flavus. Hence, dietary supplementation of NC enhanced the growth and health status of Oreochromis sp. and protected it from A. flavus infection. This study suggests the optimum inclusion level of NC is a 50–60 mg/kg diet.

The present study investigated the effect of Chlorella vulgaris on growth performance, feed consumption, body composition, and immune response of white shrimp (Litopenaeus vannamei) against Vibrio parahaemolyticus infection. Shrimps (4.00 ± 0.04 g) were divided into five groups (3 replicates/20 each) in 15 hapa (1 m³) and cultured for 56 days with five C. vulgaris experimented diets at five different concentrations (0, 15, 20, 25, and 30 g/kg feed). Growth performance, feed utilization, biomass, and body composition (protein, lipid, and ash) were analyzed and revealed significant increase (P < 0.05) in shrimp fed the high C. vulgaris diet. Additionally, the survival rate of shrimp in all experimental feeds was improved, but was not significant. Shrimp fed with C. vulgaris at different concentrations showed significantly (P < 0.05) higher antioxidant activity. The study showed that shrimp fed with a concentration of 30 g/kg C. vulgaris in the diet showed significantly (P < 0.05) highest disease resistance against the pathogen tested. Hence, dietary C. vulgaris might be used to improve growth performance, feed utilization, body composition, and immune biomarker responses, leading to disease resistance in cultured shrimp.

The use of phytobiotic as functional feed additives is a promising inducer for growth performance and immune response in the Pacific whiteleg shrimp (Litopenaeus vannamei). It can be also commercially applied in combination with chemotherapeutic agents and vaccines. This study was carried out to evaluate the use of a commercial phytobiotic feed additive, Sanacore® GM, containing vegetable fatty acids and inactivated Saccharomyces cerevisiae with herbal extracts, on growth, body composition, non-specific immune response, antioxidant index, intestinal microflora count, and fungal resistance to Fusarium solani challenge in Pacific white shrimp, Litopenaeus vannamei. Shrimp juveniles (5.00 ± 0.1 g) were randomly distributed into 12 hapas (1 m³) in triplicates at a stocking density of 20 shrimp per hapa and fed increasing levels of Sanacore® (0, 0.1, 0.2, and 0.3%) for 63 days. At the end of the feeding trial, the experimental shrimp were infected with F. solani, and mortality was recorded for 15 days. Results revealed that growth performance, feed utilization, and whole-body protein deposition were improved with increasing dietary sanacore levels. A significant improvement was reported in cellular (hemocyte counts, phagocytosis, phagocytic index, respiratory burst activity) and humoral (lysozyme and phenoloxidase) immune responses with higher dietary sanacore levels. Superoxide dismutase, catalase, and glutathione peroxidase were notably improved in shrimp-fed sanacore-supplemented diets. Meanwhile, malondialdehyde level was significantly decreased in all sanacore-supplemented shrimp. Furthermore, the dietary sanacore consistently increased probiotic bacterial counts and decreased enteric and Clostridium sp. counts in the intestine. Juveniles fed with Sanacore exhibited significantly lower mortality rates when challenged with F. solani. In conclusion, dietary sanacore could exhibit a profitable effect on the growth performance, antioxidant capacity, immunity, intestinal microbial, and the health condition of L. vannamei. Thus, sanacore can be used as an attractive feed supplement in the L. vannamei diet (0.2–0.3%), providing more insights into its application in aquaculture as a functional immunostimulant feed additive.

Shrimp culture is quite important and popular across the world. This study aimed to evaluate the growth-promoting potential of synthesized selenium nanoparticles from Spirulina platensis extract (SP-SeNPs) as a food source for Pacific whiteleg shrimp (Litopenaeus vannamei). However, pollution is considered a significant element affecting shrimp health and development. The effectiveness of SP-SeNPs in alleviating the negative effects of cadmium toxicity was also evaluated. Firstly, the shrimps (about 120 individuals with 6.0 ± 0.12 g of initial weight) were divided randomly into four groups in triplicates (30 shrimps/ treatment). The control group (SP-SeNPs—0 mg/kg diet) and three treatments were fed dietary SP-SeNPs (0.250, 0.50, and 1.0 mg/kg diet) for 56 days. Growth performance, digestive enzymes activities (protease, amylase, and lipase), and other biochemical components (total protein, lipid, amino acids, and carbohydrate) were evaluated. After 56 days of growth, another 150 adult shrimps were used under laboratory conditions to determine median lethal concentration of cadmium (96 h LC₅₀), and 30 individuals were treated with cadmium (1/2 of LC₅₀, 0.2 mg L⁻¹) for 10 days only. Tissue samples were collected for measuring catalase (CAT), total antioxidant capacity (TAC), superoxide dismutase (SOD), malondialdehyde (MDA) levels, cadmium bioaccumulation, and histopathological investigation. The results illustrated that the application of SP-SeNPs as feed additives at varying levels significantly improved growth performance (high weight gain, specific growth rate, and low feed conversion rates) relative to the control group. Furthermore, dietary SP-SeNPs enhanced digestive enzyme activities and the concentrations of biochemical components more than the control group. Upon concurrent exposure to cadmium, the antioxidative status was significantly enhanced, and histopathological alterations were mitigated. In conclusion, this study recommended supplementation of SP-SeNPs at 0.50 mg/kg diet to enhance optimal growth rate, digestive enzyme activities, levels of antioxidants in Litopenaeus vannamei, and mitigate the pathological alternations induced with Cd toxicity.