Effects of kelp residues fermented with probiotics on the culture of sea cucumber,Apostichopus japonicus

Abstract

The kelp aquaculture production in China is the largest in the world, and a large amount of kelp residue is produced by kelp processing. Kelp residues contain substantial quantities of crude fibre, protein, and residual alginic acid, and may be used as feedstuff for aquaculture animals. In this study, we used probiotics to ferment kelp residues to improve kelp nutrient content and then fed the fermented kelp to the sea cucumber, Apostichopus japonicus. To study the effect of fermented feed on sea cucumber, its growth performance, digestive enzyme activity, diversity of intestinal microbiota and water quality of the sea cucumber culture water were determined. Growth performance of sea cucumber fed with fermented feed significantly (p < .01) increased when compared with sea cucumber fed with formulated feed. Amylase, cellulose and alginase activities were significantly (p < .01) higher in the fermented feed group when compared with the formulated feed group. The total number and diversity of intestinal microbiota showed a significant increase in sea cucumbers fed with the fermented feed. The water quality of the fermented feed group showed much lower ammonia and nitrite (<0.050 mg/L) levels when compared with the formulated feed group. These results suggest that kelp residues fermented with probiotics enhance the growth, digestive enzyme activities and intestinal microbiota of sea cucumbers and improve the culture water quality. Fermented kelp residues are a new supplementary nutrient source for sea cucumbers and may be applicable to other animal aquacultures.

Effects of Lactobacillus acidophilus and tussah immunoreactive substances on disease resistance of sea cucumber ( Apostichopus japonicus ) against Vibrio splendidus

“…It is well known that assessment of the levels of digestive enzyme activity, such as amylase, trypsin and lipase, may be used as a comparative indicator of the food uptake, digestive capacity and growth performance of sea cucumbers (Wang et al, 2020). In this study, the LT group showed higher activities of trypsin and lipase relative to other groups after the feeding trial.…”

Appetite in captivity - feeding studies of the red sea cucumber Parastichopus tremulus

“…For instance, nutrient absorption in A. japonicus was improved when macroalgal diets were supplied with benthic microalgae (Gao et al, 2011), andYuan et al (2006) found that growth of juvenile A. japonicus was improved when powdered fermented algae diets were supplemented with dried bivalve faeces. Fermentation of macroalgal residues with probiotic bacteria also improved growth rates, digestive enzyme activities and intestinal microbiota in A. japonicus (Wang et al, 2020). The addition of aquaculture sludge (with a higher lipid content and higher omega-3/omega-6 fatty acid ratios) to sea cucumber feed formulations could help make up for some of the nutritional deficiencies of macroalgae.…”

“…Studies on other sea cucumber species such as Holothuria scabra has shown that aquaculture waste products can be used as feed in integrated sea cucumber aquaculture systems (Robinson et al, 2019). To fully evaluate the prospects of P. tremulus as an IMTA candidate species for Norway, it would be necessary to evaluate further the performance and growth when fed different feed sources, and also investigate the possibility of further improvement of sludge by microbiological pre-processing to achieve increased digestibility and/or probiotic function (Bao et al, 2017;Wang et al, 2020).…”

Effects of feed supplemented with probiotics on the culture of sea cucumber Apostichopus japonicus

“…All diets were mixed with sea mud at a weight ratio of 1:2 before feeding (Xie et al, 2016). The remaining uneaten feed and faeces were syphoned before changing the water, one-third of water was exchanged with sand-filtered seawater in the afternoon every day, and seawater was exchanged fully every 7 days (Wang et al, 2020). During the experiment, the levels of dissolved oxygen in water were maintained above 5.0 mg L −1 , the temperature of culture was maintained at 20 ± 2°C, pH was maintained at 7.5-8.0, and water salinity was maintained at 25-30‰.…”