Effect of an Indigenous Isolates (Aspergillus niger and Pseudomonas fluorescence) on Nutrient Content of Distillery Spent Wash (DSW)

Abstract

An experiment was conducted during 2024-25 at the Soil and Water Management Research Unit, NAU, Navsari to evaluate the efficacy of microbes for degradation of DSW using FCRD with three treatments (M0-without inoculation, M1-Aspergillus niger at 1 g/L and M2-Pseudomonas fluorescens at 10 ml/L) and five replications. Microbial inoculation significantly influenced nutrient composition and heavy metal content. Pseudomonas fluorescens (M₂) was the most effective in reducing nitrogen (32.16% reduction) and phosphorus (97.39 mg/L) with the greatest effect observed on the 10th day of incubation (M₂D₁). Sulphate content was also reduced under M₂D₁ (5,218.00 mg/L). In contrast, Aspergillus niger (M₁) efficiently reduced potassium (5,483 mg/L), sodium (407.6 mg/L), calcium (998.9 mg/L), magnesium (1,206.9 mg/L) and heavy metals, including iron, manganese, zinc and copper, particularly during early incubation (M₁D₁). The maximum reduction was observed on 10th day reflects peak microbial activity due to enhanced enzymatic action and metal biosorption. Overall, the findings indicated that these indigenous microbial isolates (Aspergillus niger and Pseudomonas fluorescens) can effectively reduce major nutrients and heavy metals in DSW.