A Biofloc-Based Aquaculture System Bio-augmented with Probiotic Bacteria Bacillus tequilensis AP BFT3 Improves Culture Environment, Production Performances, and Proteomic Changes in Penaeus vannamei.

Experiments were conducted to evaluate the probiotic effect of bio-augmented Bacillus tequilensis AP BFT3 on improving production, immune response, and proteomic changes of Penaeus vannamei reared in a biofloc system. Penaeus vannamei larvae (PL13) were stocked in 100-L tanks at a rate of 100 no per tank to study the effect of B. tequilensis AP BFT3 with and without biofloc (BFT-PRO and PRO). Control tanks devoid of probiotic strain were maintained in a clear water system. The growth and survival considerably increased in probiotic added biofloc reared shrimp than probiotic added clear water reared ones and control. Water quality significantly improved in probiotic added (PRO) and biofloc-probiotics (BFT-PRO) system than control. Microbiological investigations indicate increased heterotrophic bacterial load in BFT-PRO compared to the PRO and control. The quality of the isolated microbes was analyzed in terms of enzyme production, and an abundance of enzyme-producing bacterial population was observed in BFT-PRO shrimp. Immune-related genes were significantly upregulated in BFT-PRO shrimp, followed by the PRO and control. The proteomic data (2D gel electrophoresis and MALDI-TOF) of muscle tissue from the experimental animals identified 11 differentially expressed proteins. The Daxx OS and Lit v 1 tropomyosin was found upregulated in BFT-PRO shrimps. Downregulation of Na+/K+ATPase was observed in biofloc with probiotic-supplied groups. The findings revealed that the BFT system's efficacy could be improved through the addition of probiotics. The addition of B. tequilensis AP BFT3 as a probiotic in biofloc induced the expression of essential proteins, reducing contracting diseases during culture.

Bioaugmentation of biofloc system with enzymatic bacterial strains for high health and production performance of Penaeus indicus.

The beneficial effects of two probiotic bacterial strains Marinilactibacillus piezotolerans and Novosphingobium sp. during the culture of Indian white shrimp, Penaeus indicus, under biofloc and clear water system were evaluated. The experimental variation were CW1 (M. piezotolerans in clear water), BFT1 (biofloc + M. piezotolerans), CW2 (Novosphingobium sp. in clear water), BFT2 (biofloc + Novosphingobium sp.) and control (without bacterial strains and biofloc). Growth and survival considerably increased in probiotic bio-augmented treatments. Probiotic incorporation significantly improved water quality, especially ammonia reduction. Microbiota analysis from gut samples taken from different treatments revealed varied microbial population structure among clear water culture, biofloc culture and control. Proteobacteria and Firmicutes were the top phyla observed in the treatments which were significantly higher in bio-augmented systems than the control. Vibrio genera were predominantly observed in control and clear water system compared to that of biofloc systems. Immune genes were significantly altered in response to probiotic gut microbial supplementation than the control. Higher gene expression profile of important immune genes was observed in the biofloc reared shrimps. Expression of digestive enzyme related genes such as trypsin, chymotrypsin, cathepsin L, cathepsin B and alpha amylase were also upregulated significantly in probiotic supplementation especially in the biofloc treatments. Proteomic analysis of hepatopancreas of shrimps from different treatments was carried out by using 2D gel electrophoresis and MALDI-TOF analysis. The proteins were mostly related to growth and stress tolerance. Eukaryotic initiation factor 4E binding protein was expressed in all the groups and it was high in biofloc treated animals followed by animals treated solely with probiotics compared to those of control groups. The results concludes that biofloc already proved as an effective culture method for healthy shrimp production and supplementation of probiotic bacterial strains registered additional benefit for growth, survival, microbial, immunological status of P, indicus culture.

Media preparation using tuna-processing wastes for improved lipase production by shrimp gut isolate Staphylococcus epidermidis CMST Pi 2.

Extracellular lipase production by Staphylococcus epidermidis CMST Pi 2 isolated from the intestine of shrimp Penaeus indicus has been investigated in shake-flask experiment using different preparations of tuna-processing waste such as raw fish meat, defatted fish meat, alkali hydrolysate, and acid hydrolysate as nitrogen source. Among the tested tuna preparations, defatted fish meat supported the maximum lipase production, and 2.5% concentration of the same was found to be optimum for maximizing the lipase production. The effect of carbon sources on lipase production revealed that glucose aided the higher lipase production than any other tested carbon source and a concentration of 2% glucose registered as optimum to enhance the lipase production. The halotolerancy of S. epidermidis CMST Pi 2 for lipase production indicated that 4% of sodium chloride was optimum to yield maximum lipase. Among the surfactants tested, lipase production was high in Tween 20 added medium when compared to other surfactants, and its optimum concentration recorded was 0.8%. Partial characterization of crude enzyme revealed that pH 7 and 55 degrees C temperature were optimum for maximum lipase activity.