Production of Value-added High Protein Fungal Biomass (HPFB) and Water Reclamation from Sago Effluent using Rhizopus oligosporus

• Main Author: Fazidah, Binti Junaidi
• Format: Thesis
• Language: English
• Published: Universiti Malaysia Sarawak (UNIMAS) 2019
• Subjects: Q Science (General); QR Microbiology
• Online Access: http://ir.unimas.my/id/eprint/26633/1/Fazidah.pdf; http://ir.unimas.my/id/eprint/26633/
• Institution: Universiti Malaysia Sarawak

The discharge of sago effluent into water bodies without proper treatment has contributed to severe water pollution. This has raised various concerns and biotechnological treatment of sago effluent wastewater is crucial. In the current study, R. oligosporus was grown in sago effluent via submerged fermentation (SmF) as a mean to reduce the organic loads. Three major parameters studied were initial pH, aeration rate and nitrogen concentration; in order to identify the optimum condition for the growth of R. oligosporus. For pH parameter, different initial pH of control (no pH set), 4, 5 and 6 were applied to investigate the optimum pH for the growth of R. oligosporus in sago effluent and to assess the growth kinetics of R. oligosporus under SmF for water treatment. Based on the data obtained, pH 4 is the optimum pH for the growth of R. oligosporus with the highest dry biomass production recorded at 3.80 g/L. Starch concentration reduction was recorded at 98%, while nitrate concentration was reduced from 0.266 to 0.257 g/L, and by nitrite levels declined from 0.040 to 0.029 g/L. The decrease of BOD level at 89.81% and COD level at 78.30% for pH 4 indicated that submerged fermentation of R. oligosporus in sago effluent at the optimal pH would be a strategic solution for water reclamation. For aeration parameter, the growth rates of R. oligosporus at aeration levels of 0.00 vvm, 0.50 vvm, 0.75 vvm and 1.00 vvm were studied. From this study, the optimal aeration rate for maximum growth of R. oligosporus was found to be 1.00 vvm. The highest dry biomass production recorded at 1.00 vvm was 3.750 g/L. This data was supported by the phenol-sulphuric test result where a significant 97.22% decrease in starch content in the sago effluent was recorded. On the other hand, the nitrate concentration was reduced from 0.267 to 0.260 g/L, while the nitrite level dropped from 0.032 to 0.029 g/L. In addition to the production of High Protein Fungal Biomass (HPFB), the reduction in starch, nitrate and nitrite concentrations would potentially benefit the environment. Moreover, the BOD and COD were found to be significantly decreased, with the respective reduction of 88.64% and 78.81%, indicating that submerged fermentation of R. oligosporus in sago effluent at the optimal rate of aeration could be a strategic remedy for water recovery. For nitrogen concentration parameter, 0 mM, 25 mM, 50 mM, and 100 mM of nitrogen, were supplemented to submerged fermentation (SmF) system to reduce organic loads. From this experiment, the optimal nitrogen concentration for maximum growth of R. oligosporus was found to be 100 mM. The highest dry biomass production recorded was 3.783 g/L at 100 mM nitrogen. This finding was supported by the phenol-sulphuric test result where a significant decrease of 97.91% in starch content in the sago effluent was recorded. On the other hand, the nitrate concentration was reduced from 0.493 to 0.473g/L, while the nitrite level dropped from 0.108 to 0.032 g/L. Moreover, the BOD and COD were found to be significantly decreased, with the respective reduction of 88.18% and 77.53%, indicating that submerged fermentation of R. oligosporus in sago effluent at the optimal nitrogen concentration could be a promising application to treat sago effluent via biological processes. The present findings demonstrated the potential of R. oligosporus for the production of HPFB and water reclamation. Keywords: High protein fungal biomass (HPFB), Rhizopus oligosporus, sago effluent, wastewater treatment, pH, aeration, nitrogen concentration.