Microalgae have well-established health benefits for farmed fish. Thus, this study aims to explore the potential protective effects of Spirulina platensis, Chlorella vulgaris, and Moringa oleifera against pyrogallol-induced hematological, hepatic, and renal biomarkers in African catfish (Clarias gariepinus), as well as the histopathological changes in the liver and kidney. Fish weighing 200 ± 25 g were divided into several groups: group 1 served as the control, group 2 was exposed to 10 mg/L of pyrogallol, and groups 3, 4, and 5 were exposed to the same concentration of pyrogallol, supplemented with S. platensis at 20 g/kg diet, C. vulgaris at 50 g/kg diet, and M. oleifera at 5 g/kg diet, respectively, for 15 days. Exposure to pyrogallol led to decreased packed cell volume (PCV) and lymphocyte count, but these effects were alleviated by microalgae interventions. C. vulgaris and M. oleifera equally restored PCV and increased lymphocyte counts. Supplementation with C. vulgaris and M. oleifera successfully normalized both neutrophil and eosinophil counts. Pyrogallol intoxication engenders an increase in glycemic status, but C. vulgaris and M. oleifera effectively mitigated this rise. Pyrogallol-exposed fish exhibited signs of renal dysfunction, with increased serum creatinine and total cholesterol levels. A significant decrease in both erythrocytic cellular and nuclear abnormalities was observed following supplementation with microalgae. C. vulgaris and M. oleifera showed promise in decreasing serum glucose and creatinine levels, and improving hematological parameters, while S. platensis exhibited limited efficacy in this regard. Exposure to pyrogallol led to a notable decrease in serum superoxide dismutase activity and total antioxidant capacity (TAC), accompanied by an increase in serum malondialdehyde (MDA) levels. Diets enriched with C. vulgaris and M. oleifera effectively restored these parameters to normal levels, whereas S. platensis did not induce significant changes. None of the microalgae improved TAC except for M. oleifera, which significantly enhanced it. MDA levels returned to control levels equally and significantly across all groups. Interleukin-6 levels did not exhibit significant differences between any of the groups. Collectively, the histopathological changes induced by pyrogallol were most prominently alleviated in the pyrogallol + C. vulgaris and pyrogallol + M. oleifera groups, and to a limited degree in the pyrogallol + S. platensis group. While the tested microalgae did not cause hepatic or renal dysfunction, they did lead to metabolic abnormalities. The incorporation of microalgae into the diet holds significant importance in mitigating the metabolic and histological toxicity of pyrogallol and should be considered in the formulation of fish feed

Endophytic fungi are a significant group of fungi found in various ecosystems, producing significant secondary metabolites with economic applications. The study aims to extract gibberellic acid from endophytic fungi, optimize its production using low-cost agriculture residues, and apply it to plants. Endophytic fungi were isolated from onion leaves, screened for gibberellic acid production, and the highest producer was identified by morphological and molecular tools. The production was optimized using three levels Box–Behnken design, and the hormone was applied to maize seeds at concentrations of 0, 50, and 100 ppm. Fusarium solani, F. oxysporum, F. incarnatum, and F. camptoceras produced gibberellic acid at concentrations from 3.04 to 36.33 mg/l, with the highest production by F. incarnatum-ASU19 (MK387876). The optimal parameters increased the production significantly (R² 0.9974) to 166.81 mg/l using 20 g/l sugarcane bagasse, 35 °C incubation temperature, and seven days of incubation. Increased gibberellic acid concentrations induced morphological characteristics, chlorophyll, flavonoids, and total antioxidants in maize compared to controls without GA₃ addition. In conclusion, the endophytic fungus Fusarium incarnatum demonstrates significant potential for gibberellic acid production from low-cost agricultural residues. This bioprocess not only promotes a cleaner environment but also enhances plant tolerance to abiotic stress and positively influences agricultural productivity.