Microbial biomass production using sugarcane industrial by-products and their application to Nile tilapia aquaculture

Abstract

The sugarcane industrial wastewater is considered as one of the main sources of River Nile pollution. Here we study the possibility of using sugarcane wastewater effluent amended with molasses and clay factory as a culture medium for growth and biomass production of Chlamydomonas reinhardtii and Azotobacter chroococcum and the possibility of using this biomass for Oreochromis niloticus aquaculture. Results of this study indicated that some physico-chemical analyses of waste water are non-compliant with Law 48/1982 such as decreasing values of dissolved oxygen (0.77 mg/1), increasing temperature (40-50°C) and increasing values of chemical oxygen demand (31.5 mgO2/l). These pollutants were dealt for growth and biomass production of Azotobacter chroococcum and Chlamydomonas reinhardtii after amendment with molasses and industrial clay (press mud). Results showed that the wastewater amended with 1% press mud, 1% molasses and 0.5g/l CaCO3 was the best for A. chroococcum. In addition, high growth of Chlamydomonas was obtained in the sugarcane wastewater amended with 1% molasses with 0.5% press mud. Moreover, addition of Azotobacter had positive effect on growth of Chlamydomonas especially when added after 24 hours of Chlamydomonas growth. Biomass of both C. reinhardtii and A. chroococcum (which was grown on sugar can industrial by-products) has high potential for Oreochromis niloticus aquaculture, where highest weight gain and specific growth rate of fish were recorded. Further research work is needed to confirm the safety and viability of this microbial biomass produced from industrial sugar cane by-products in Nile tilapia aquaculture.