Isolation and characterization of Bacillus subtilis CH16 strain from chicken gastrointestinal tracts for use as a feed supplement to promote weight gain in broilers

Lett Appl Microbiol. 2015 Jun;60(6):580-8. doi: 10.1111/lam.12411. Epub 2015 Mar 29.

Abstract

Spore-forming bacterial strains were isolated from chicken gastrointestinal tracts to develop a heat-stable feed supplement that promotes weight gain in broilers. Seven Bacillus strains having more than 90% sporulation were screened from the isolates and identified to be closely related with Bacillus subtilis and Bacillus licheniformis. Of the seven strains, B. subtilis CH16 was selected to develop a feed supplement for broilers, because it formed 100% heat-stable spores, grew rapidly at 42°C and quickly formed a biofilm. In large-scale trials in broilers (n ≥ 1150 per group), the group fed CH16 (3 × 10(6) CFU g(-1) pellet) showed higher average daily gain (ADG = 61·16) and lower food conversion ratio (FCR = 1·696) than did the group fed B. licheniformis CH22 (ADG = 57·10 and FCR = 1·792), the group fed B. subtilis HU58 (ADG = 51·90 and FCR = 1·868), BioPlus group (ADG = 59·32 and FCR = 1·807) and the control group (ADG = 56·02 and FCR = 1·880). In conclusion, CH16 spores significantly increased ADG by 9·17% and reduced FCR by 9·79% in broilers. The result supports the use of B. subtilis CH16 of chicken intestinal origin as a feed supplement that promote weight gain in broilers. Significance and impact of the study: This study reports screening of Bacillus strains isolated from chicken gastrointestinal tracts for development of a feed supplement that promote weight gain in broilers. Of the seven Bacillus isolates with high sporulation efficiency (≥90%), Bacillus subtilis CH16 strain showed the best growth and biofilm formation at body temperature of broilers (42°C). In large-scale trials in broilers (n ≥ 1150 per group), CH16 spores induced a 9·17% increase in daily weight gain (ADG) and a 9·79% reduction in FCR while the commercial BioPlus(®) YC induced only a 5·89% increase in ADG and a 3·88% reduction in FCR.

Keywords: Bacillus spore; broiler; feed supplement; gastrointestinal tract; probiotic; weight gain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed / microbiology
  • Animals
  • Bacillus subtilis / genetics*
  • Bacillus subtilis / growth & development
  • Bacillus subtilis / isolation & purification
  • Base Sequence
  • Biofilms / growth & development
  • Chickens / microbiology*
  • DNA Gyrase / genetics
  • DNA, Bacterial / genetics
  • Dietary Supplements / microbiology
  • Gastrointestinal Tract / microbiology
  • Meat
  • Probiotics / pharmacology*
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Spores, Bacterial / metabolism*
  • Weight Gain / drug effects*

Substances

  • DNA, Bacterial
  • RNA, Ribosomal, 16S
  • DNA Gyrase