Combined treatment with α-amylase and Saccharomyces cerevisiae culture for nutrient removal and biomass production in effluent from rice parboilization

• Published in: Desalination and water treatment Vol. 243; pp. 200 - 205
• Main Authors: Fehrenbach, Gustavo W., Leite, Fábio P.L., Santos, Diego G.L.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-12-2021
• Subjects: Bioproducts; Bioremediation; Effluent treatment; Enzymatic treatment; Parboiling process; Parboiling process; Enzymatic treatment; Bioproducts; Effluent treatment; Bioremediation
• ISSN: 1944-3986; 1944-3986
• DOI: 10.5004/dwt.2021.27886

In this study, we report a non-supplemented and biomass productive treatment for parboiled rice effluent (PE) combining a pre-treatment with α-amylase followed by Saccharomyces cerevisiae culture. PE with amylase (PEA) was pre-treated with 5 mg L–1 of α-amylase for 12.5 min at 50°C – a non-enzymatic culture with PE was used as the negative control. Both cultures were inoculated with 10% v/v of S. cerevisiae at a concentration of 1.2 × 103 CFU mL–1 for 48 h. The highest level of glucose was 1.75 g L–1 and obtained in PEA culture, 40% higher than in the control PE. CFU and biomass followed the glucose levels and were 73% and 62.9% higher than in PE, with a maximum of 3.35 × 108 CFU mL–1 and 2 g L–1, respectively. The highest removals were obtained in PEA for phosphorus (40.68%), PE for organic matter (70%), and 100% of removal for total nitrogen in both cultures. The low cost of the method (0.45$ per m3), nutrient removals (40.68% P, 100% TKN, 62% COD), cell viability (3.35 × 108 CFU mL–1) and biomass (2 g L–1) suggests that α-amylase improves the bioremediation potential of S. cerevisiae cultured in PE and can provide a widely marketable biomass as by-product.