Fish Waste Management Methods Based on Microorganisms 225
Two bacteria, Bacillus subtilis and Bacillus megaterium, were added to
the recirculating-water systems of the grow-out facilities of red-parrot fi sh
(male Cichlasoma citrinellum × female Cichlasoma synspilum). The results
indicated that total ammonia nitrogen concentrations were held below 5.4
mg/l, while COD remained below 40.8 mg/l or less, the transparency of
the recirculated aquarium water remained at 30-50 cm, and the survival
rate and quality of fi sh were signifi cantly improved (Chen and Chen,
2001).
In another study, a procedure for the extraction of protein and
production of peptides by enzymic hydrolysis from bone and skin wastes
containing collagen was fully developed. Fat and inorganic components
were fi rst removed in a pretreatment step and a high molecular weight
protein extracted under acidic conditions (pH 3) using a 1 h reaction time
at 60°C. The extract was shown to have a high water retention capacity,
was benefi cial for repair of rough skin, had no odour problem and was
demonstrated to be safe in skin patch tests. It was thereby considered
acceptable for use in cosmetic materials. Pretreated fi sh bone and pig skin
were hydrolysed with a commercial enzyme. The hydrolysates had a high
anti-radical activity (IPO X 50, 0.18 and 0.45 mg/ml) and a high potential
for decreasing blood pressure (IC50, 0.16 and 0.41 mg/ml), proposing the
hydrolysates could be potentially useful as additives in food materials
(Morimura et al., 2002).
In recent years, there has been growing interest in biocontrol of microbial
pathogens in aquaculture using antagonistic microorganisms (Westerdahl
et al., 1991; Maeda, 1994; Chapter 1 and 2 in this Volume). The microbial
species composition in hatchery tanks or large aquaculture ponds can be
changed by adding selected bacterial species to displace deleterious normal
bacteria. Abundance of luminous Vibrio strains decreased in shrimp ponds
and hatchery tanks waters where specially selected, probiotic strains of
Bacillus species were added. When the probiotic bacteria were used, no
disease was experienced and indeed shrimp survival was extremely high
(80-100%), even in the presence of luminous Vibrio species in all ponds
treated with probiotics (Moriarty, 1999).
The treatment methods based on the use of Bacillus sp. for fi sh waste
remediation (parameters, quality control and results) are shown in
Table 9.3.
Lactobacillus sp.
Fish wastes were mixed with 15% molasses, inoculated with 5% starter
culture of Lactobacillus plantarum, incubated at 22 ± 2°C for 20 d, and
then stored for 20 d. The obtained product was incorporated with bran
and ground barley to make different formulas and then fed to broilers. A
signifi cant pH decrease (initial value 6.13-6.75) in the fermenting product
Two bacteria, Bacillus subtilis and Bacillus megaterium, were added to
the recirculating-water systems of the grow-out facilities of red-parrot fi sh
(male Cichlasoma citrinellum × female Cichlasoma synspilum). The results
indicated that total ammonia nitrogen concentrations were held below 5.4
mg/l, while COD remained below 40.8 mg/l or less, the transparency of
the recirculated aquarium water remained at 30-50 cm, and the survival
rate and quality of fi sh were signifi cantly improved (Chen and Chen,
2001).
In another study, a procedure for the extraction of protein and
production of peptides by enzymic hydrolysis from bone and skin wastes
containing collagen was fully developed. Fat and inorganic components
were fi rst removed in a pretreatment step and a high molecular weight
protein extracted under acidic conditions (pH 3) using a 1 h reaction time
at 60°C. The extract was shown to have a high water retention capacity,
was benefi cial for repair of rough skin, had no odour problem and was
demonstrated to be safe in skin patch tests. It was thereby considered
acceptable for use in cosmetic materials. Pretreated fi sh bone and pig skin
were hydrolysed with a commercial enzyme. The hydrolysates had a high
anti-radical activity (IPO X 50, 0.18 and 0.45 mg/ml) and a high potential
for decreasing blood pressure (IC50, 0.16 and 0.41 mg/ml), proposing the
hydrolysates could be potentially useful as additives in food materials
(Morimura et al., 2002).
In recent years, there has been growing interest in biocontrol of microbial
pathogens in aquaculture using antagonistic microorganisms (Westerdahl
et al., 1991; Maeda, 1994; Chapter 1 and 2 in this Volume). The microbial
species composition in hatchery tanks or large aquaculture ponds can be
changed by adding selected bacterial species to displace deleterious normal
bacteria. Abundance of luminous Vibrio strains decreased in shrimp ponds
and hatchery tanks waters where specially selected, probiotic strains of
Bacillus species were added. When the probiotic bacteria were used, no
disease was experienced and indeed shrimp survival was extremely high
(80-100%), even in the presence of luminous Vibrio species in all ponds
treated with probiotics (Moriarty, 1999).
The treatment methods based on the use of Bacillus sp. for fi sh waste
remediation (parameters, quality control and results) are shown in
Table 9.3.
Lactobacillus sp.
Fish wastes were mixed with 15% molasses, inoculated with 5% starter
culture of Lactobacillus plantarum, incubated at 22 ± 2°C for 20 d, and
then stored for 20 d. The obtained product was incorporated with bran
and ground barley to make different formulas and then fed to broilers. A
signifi cant pH decrease (initial value 6.13-6.75) in the fermenting product