H T Ngo1, T T N Nguyen1, Q M Nguyen2, A V Tran2, H T V Do3, A H Nguyen4, T-N Phan1, A T V Nguyen5. 1. Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam. 2. High School for Gifted Students, VNU University of Science, Hanoi, Vietnam. 3. Faculty of Chemistry, VNU University of Science, Hanoi, Vietnam. 4. ANABIO Research & Development JSC, Hanoi, Vietnam. 5. Key Laboratory of Enzyme and Protein Technology, VNU University of Science, Hanoi, Vietnam. vananhbiolab@gmail.com.
Abstract
AIMS: To develop a novel feed supplement for shrimp using pigmented spore-forming bacterial strains isolated from their gastrointestinal tracts. METHODS AND RESULTS: Eight pigmented Bacillus strains were selected from the isolates based on high production of heat-stable spores, typical UV-Vis spectra of produced carotenoids (400-550 nm), and free radical scavenging activity of their extracts. Of the eight strains, the red-orange pigmented Bacillus aquimaris SH6 was selected because it showed the highest abundance in shrimp guts (70% population). Whiteleg shrimp (n = 30 per group) fed with SH6 spores, at >3 × 106 CFU g-1 pellet for 4 weeks had redder colour (score of 21-23 vs 20-22), 2·7-fold higher astaxanthin level (0·69 vs 0·25 μg g-1 shrimp), 34% higher weight gain (7·18 vs 5·32 g shrimp-1 ), and 85% higher phenoloxidase activity (OD490 = 0·265 vs 0·143) than shrimp in the control group. CONCLUSIONS: The result supports the potential use of B. aquimaris SH6 as a feed supplement for promoting the colourization and weight gain, and for enhancing innate immunity of whiteleg shrimp. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that carotenoids produced by B. aquimaris SH6 can be successfully absorbed and converted to astaxanthin in whiteleg shrimp.
AIMS: To develop a novel feed supplement for shrimp using pigmented spore-forming bacterial strains isolated from their gastrointestinal tracts. METHODS AND RESULTS: Eight pigmented Bacillus strains were selected from the isolates based on high production of heat-stable spores, typical UV-Vis spectra of produced carotenoids (400-550 nm), and free radical scavenging activity of their extracts. Of the eight strains, the red-orange pigmented Bacillus aquimaris SH6 was selected because it showed the highest abundance in shrimp guts (70% population). Whiteleg shrimp (n = 30 per group) fed with SH6 spores, at >3 × 106 CFU g-1 pellet for 4 weeks had redder colour (score of 21-23 vs 20-22), 2·7-fold higher astaxanthin level (0·69 vs 0·25 μg g-1 shrimp), 34% higher weight gain (7·18 vs 5·32 g shrimp-1 ), and 85% higher phenoloxidase activity (OD490 = 0·265 vs 0·143) than shrimp in the control group. CONCLUSIONS: The result supports the potential use of B. aquimaris SH6 as a feed supplement for promoting the colourization and weight gain, and for enhancing innate immunity of whiteleg shrimp. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that carotenoids produced by B. aquimaris SH6 can be successfully absorbed and converted to astaxanthin in whiteleg shrimp.
Authors: Huong Thi Nguyen; Tham Thi Nguyen; Huong Thi Thu Pham; Que Thi Ngoc Nguyen; My Thi Tran; Anh Hoa Nguyen; Tuan Nghia Phan; Ha Thi Viet Bui; Hien Thi Thanh Dao; Anh Thi Van Nguyen Journal: PLoS One Date: 2018-12-21 Impact factor: 3.240