Fish Waste Management: Treatment Methods Based on the Use of Microorganisms - Aquaculture Microbiology and Biotechnology - page 224

26 ± 2°C and a pH of 6.5 ± 0.5. Total ammonia nitrogen (TAN) and nitrite
nitrogen concentration decreased to 0.35 mg/l and 0.12 mg/l, respectively
( Fig. 9.1 ) .
The treatment methods based on the use Aspergillus sp. for aquaculture
waste remediation (parameters, quality control and results) are presented
in Table 9.1.

Bacillus sp.
Prawn nursery wastewaters were fi rst fi ltered by sand fi lter, sterilised by
ultraviolet reactor, and spores of Bacillus subtilis were added to the effl uents
under conditions of continuous aeration. The remediated water was then
fi ltered through sand fi lter. Three experiments were conducted; in the fi rst
experiment the degradation of dissolved organic matter (DOM) and TAN
without nutrient addition was investigated; in the second experiment the
effects of four nutrients (glucose, potassium dihydrogen phosphate, micro-
elements solution, and vitamin mixture) on bioremediation performance;
and fi nally in the third experiment the detection of an optimal rationale
of nutrients addition for removing ammonium and avoiding second
contamination during bioremediation. After 48 h, Chemical Oxygen
Demand (COD) removal was up to 57.5 ± 5.5%, and DOM was degraded
directly. From d 2 to d 5 TAN removal was decreased, whereas the addition
of glucose and/or phosphate supported TAN removal (> 85%) ( Fig. 9.1 ) .
The addition of vitamin mixture and/or micro-elements solution did not
affect the TAN removal. The optimal rates of C/N or N/P for wastewater
remediation were 5.4/1 or 5-7/1, respectively. After 5 d of microbial
remediation the wastewater became suitable for reuse (Liu and Han,
2004).
The role of probiotic cell wall hydrophobicity in bioremediation of
aquaculture was examined by Wang and Han (2007). Bacillus sp. YB-
030518 and Bacillus sp. YB-034325 (1% inoculation) with different levels of
cell wall hydrophobicity were added to basal shrimp feed at 30°C for 96
h. The results revealed that there was no signifi cant difference in cell wall
hydrophobicity between the two strains of Bacillus sp . at pH 5.5, 7.0 and
8.5, at 5°C and 20°C. Bioremediation capability (%) at 48 h and 96 h was
signifi cantly higher for YB-034325 compared to YB-030518 ( Table 9.2 ) .

Table 9.2 Bioremediation capability and cell hydrophobicity of Bacillus sp. YB-030518
and -034325 (Wang and Han, 2007)

Bacillus spp.

Bioremediation capability (%) Cell hydrophobicity (%)

48 h 96 h 18 h 96 h

Bacillus sp. YB-030518 55 60 63.3 34.3

Bacillus sp. YB-034325 65 70 71.3 43.3