Growth and survival of rohu, Labeo rohita (Hamilton) spawn fed diets fermented with intestinal bacterium, Bacillus circulans

Abstract

Background. Because of the advancement of multiple spawning of carps, the importance of a quality larval diet is increasing day by day. The larval fish do not have the necessary enzyme or the amount of digestive enzymes to digest feed at optimum level. Therefore, fermentation of feed ingredients and/or formulated diets by bacterial enzymes to produce simpler forms of nutrients may be beneficial for them. Materials and methods. Five isocaloric (4.38 kcal•g-1) and isonitrogenous (35% crude protein approximately) experimental diets (D1-D5) containing 32% fish meal, 34% mustard oil cake, 30% rice bran, and 2% cod liver oil, were fermented in vitro with Bacillus circulans cells (at the rate of 10 8 bacterial cells per g) at 37°C for 1-5 day duration (1 day: D1, 2 days: D2, 3days: D3, 4 days: D4, and 5 days: D5). The bacterial strain [extracellular enzyme producer Bacillus circulans (Lr 1.1)] used for fermentation was isolated from the intestine of rohu, Labeo rohita fingerlings. The reference diet (RD), containing same ingredients, was not fermented with bacterial cells. Rohu spawn (av. wt. 0.35 ± 0.01 mg) were fed ad libitum for 21 days in the laboratory condition at 30 minutes interval starting from 0900 h to 1600 h. Results. Fermentation of diets resulted in an increase in crude protein and free amino acid contents and decrease in crude fibre content. Diets D4 and D5 resulted in best growth and survival (98% and 98.33%, respectively) of rohu spawn compared to those fed with the reference diet (RD) and other experimental groups. A significant positive correlation was obtained between RNA : DNA ratio and specific growth rate (SGR) of 18 dietary groups (6 groups in triplicate). Conclusion. Fermentation of feed ingredients may be practiced as a tool for starter diet formulation to obtain better growth and survival of rohu spawn. The enzymeproducing strain, Bacillus circulans could be used to ferment diets for 4 to 5 days to increase the bioavailability of nutrients.

Study on Bacillus Isolated from Intestine of Persian Sturgeon (<i>Acipenser persicus</i>) Comparing with Commercial Probiotics

“…Also, commercial lactobacillus supplemented at level 7.2 log colony unit in each gram, had better performance. Similar results were obtained by Ghosh et al in 2004 about supplementation of diets fed to Rohita fish larvae at level equal to 10 8 CFU/g feed, so that special growth rate was increased from 10.89 to 17.79 [21]. Corresponding to these results, Jafaryan et al in 2009 showed that special growth rate of Persian sturgeon larvae fed by rations supplements with spore bacillus formis and bacillus laterosporus at concentration of 4 10 7 in each gram feed, was increased from 5.84 to 6.41, of body weight.…”

“…The best result was derived through supplementation rations with bacillus isolated from intestine of sturgeon fish in concentration of 6.1 log colony unit in each gram feed. Similar to these results, Ghosh et al in 2004 confirmed that bacillus cerculance isolated from intestine of fish species, Labeo rohita, at the level equal to 2  10 8 CFU feed, Changed the weight of fry from 3.45 to 4.61g [21]. According to these results, Ghosh et al in 2002 showed that bacillus isolated from intestine of labeo rohita fish has more effect on increased weight of larvae of this fish than commercial bacillus [12,13].…”

Dietary supplementation of probiotics improves survival and growth of Rohu (Labeo rohita Ham.) hatchlings and fry in outdoor tanks

“…Early juveniles lack necessary digestive enzymes to digest feed to its maximum extent (Ghosh et al, 2004). Several efforts have been made to develop artificial feed including microencapsulated diet for better rearing of fish larvae (Ghosh et al, 2004). In addition to feed quality, bacterial infection causes mass mortality (Rigos and Troisi, 2005;Salah et al, 2008;Vadstein et al, 2012).…”

“…Poor survival of fish larva is mostly due to pathogen and unavailability of suitable diet (Edwards, 2013;Little et al, 2002). Early juveniles lack necessary digestive enzymes to digest feed to its maximum extent (Ghosh et al, 2004). Several efforts have been made to develop artificial feed including microencapsulated diet for better rearing of fish larvae (Ghosh et al, 2004).…”

Distribution of extracellular enzyme-producing bacteria in the digestive tracts of 4 brackish water fish species

“…The use of beneficial bacteria as probiotics has a long tradition in animal husbandry (Stavric and Kornegay, 1995). Beneficial bacteria could be introduced in commercial aquaculture by incorporating them into formulated fish diets, or in the form of bacteria biofilm to achieve colonization in the GI tract to a higher degree (Bairagi et al, 2002(Bairagi et al, , 2004Ghosh et al, 2002bGhosh et al, , 2003Ghosh et al, , 2004aGhosh et al, , 2004bRamachandran et al, 2005;Ramachandran and Ray, 2007;Askarian et al, 2011;Saha and Ray, 2011). It has been suggested that beneficial gut bacteria are continuously competing with pathogens through competitive exclusion (Ray et al, 2012).…”