Nowadays, Fisheries is considered one of the most important resources. By increasing the population over the world, aquaculture is one of the very important ways to provide food for humans. Aquaculture includes Litopenaeus vannamei farming by biofloc technology in presence of organic carbon sources with consideration the heavy metals and other wastes pollution. In this experiment, L. vannamei is cultured using sugarcane bagasse (T1) and rice bran (T2) as carbon sources with following up of the growth of heterotrophic bacteria (THB) and Vibrio bacteria (TVC) as an indicator for pathogenic bacteria and their impacts on metals level in water resulting from aquaculture process.
Over 120 days, the number of total heterotrophic bacteria and Vibrio bacteria in the control was lower than the other treatments (T1 & T2). As for the effect of carbon sources, the number of bacteria in the sugarcane bagasse (T1) was greater than rice bran (T2). The highest number of total heterotrophic bacteria was at the end of the experiment (Figure 1).
Looking at the metal results, it was found that the mean values of control samples in the first of study were (0.8503, 5293, 0.4035, 0.2313, 0.1071, 0.0279 and 0.0765 µg L–1) while at the end of the study these values were (0.8632, 0.4675, 0.3764, 0.2242, 0.0930, 0.0237 and 0.0795 µg L–1) for Cu, Zn, Pb, Cd, Ni, Co and Mn, respectively. In the same order of metals it was found that the percentage of metal removal were {(85, 76); (71, 66.5); (93, 89); (83, 75); (84.1, 76.1); (78.4, 59.5) and (81.8, 69.5){for sugarcane bagasse and rice ban, respectively (Figure 2).
Acknowledgements: The research was performed within the "EGY-DRAFT" project (Development and Research Application of bioFloc Technology for increasing shrimp production in Egypt), funded by the Science, Technology & Innovation Funding Authority (STDF), Egypt. Agreement No.: 25305/Reintegration Grants (STDF-RG)/STDF-Youth. The authors are grateful for all the support.