Probiotic activity of Bacillus subtilis in juvenile freshwater prawn, Macrobrachium rosenbergii (de Man) at different methods of administration to the feed

Abstract

This experiment was carried out to investigate the potential probiotic properties of Bacillus subtilis and suitable methods of administration to the commercial feed in juvenile Macrobrachium rosenbergii (de Man) from 25 August to 25 November 2008. Putative Bacillus subtilis bacterium isolated from juvenile M. rosenbergii intestine was added to commercial prawn feed as a probiotic. Five types of diets were prepared by mixing B. subtilis at level of 108 cells g -1 with commercial feed using different methods consisting mixing, soaking, spraying and bathing. After 60 days, the prawns fed diets at soaking method treated group, showed a higher mean weight gain (2.09) or 328.84% increase in growth over control. There were significant differences (P \ 0.05) in weight gain, feed intake and FCR among soaking method and other treated and control groups. There was significant difference (P \ 0.05) in survival among treated and control groups, but no significant difference (P [ 0.05) in water quality and biochemical composition among treated and control groups. Clearly, B. subtilis-treated diets appeared to enhance growth and survival of juveniles M. rosenbergii. It was concluded that the tested strain may be a promising probiotic for M. rosenbergii under soaking method of administration to the prawn commercial feed.

Effect of Bacillus subtilis on Aeromonas hydrophila infection resistance in juvenile freshwater prawn, Macrobrachium rosenbergii (de Man)

“…After 60 days of feeding, total bacterial count in water from each culture tank was 10 10 cells mL -1 , regardless of treatment. The same result was reported by Keysami et al (2012). The B. subtilis concentration increased to 10 8 -10 10 cells mL -1 in all treated tanks through the first 60 days, but was not found in the control tanks.…”

“…The recent reports on the use of Bacillus spp. (Balcazar et al 2004;Salinas et al 2005;Keysami et al 2012) also demonstrated the beneficial effects of stimulating the growth improvements and gut immune system in the fish and prawn (Abraham et al 2008). After 60 days of feeding, total bacterial count in water from each culture tank was 10 10 cells mL -1 , regardless of treatment.…”

“…The B. subtilis-treated diet was prepared according to Keysami et al (2012) by soaking commercially available M. rosenbergii pellet feed (Havorash, Bushehr, IRI) with normal saline (NSS; Nacl 8.5 g L -1 ) containing the B. subtilis fresh cells. Bacterium was grown for 48-72 h at 30°C in Trypton Soy broth (Difco, CO, USA) and harvested by centrifugation 4,000g for 15 min.…”

“…The cells were re-suspended in original volume of saline to 5 9 10 13 cells mL -1 . This suspension was then applied to unsoaked diet to achieve a counted viable dose approximately equivalent to 5 9 10 8 cells g -1 of feed after absorbing whole bacteria suspension during 1 h. This level of B. subtilis (10 8 cells g -1 ) was chosen based on earlier works of researchers (Meunpol et al 2003;Keysami et al 2012). The control diet also was prepared by soaking the same basis pellet feed with normal saline without the B. subtilis fresh cells.…”

“…Probiotics are live micro-organisms that when consumed in adequate amount confer a health benefit for the host (FAO/WHO 2001). Appropriate probiotics applications were shown to improve intestinal microbial balance, thus leading to improved feed utilization (FAO 2007;Keysami et al 2012) and reduced pathogenic problems in the gastrointestinal tract (Scan 2003). In the aquaculture industry, several probiotics species have been used, including Lactobacillus sp.…”