Establishment, Identification, Quantification of Methanogenic Archaea in Chicken Ceca and Methanogenesis Inhibition in in Vitr

Establishment, Identification, Quantification of Methanogenic Archaea in Chicken Ceca and Methanogenesis Inhibition in in vitro Chicken Ceca by Using Nitrocompounds. (May 2006) Suwat Saengkerdsub, B.S., Chulalongkorn University; M.S., Chulalongkorn University Co-Chairs of Advisory Committee: Dr. Steven C. Ricke Dr. Jimmy T. Keeton In the first phase of this study, the diversity of methanogenic bacteria in avian ceca was found to be minimal. Based on 16S rDNA clone libraries, a common phylotype, designated CH101, ranged between 92.86 to 100 % of the total clones whereas less than 1% of the other phylotypes were found. On the basis of the sequence identity, all of the sequences, except sequence CH1270, are related from 98.97 to 99.45% to 16S rDNA Methanobrevibacter woesei GS. Sequence CH1270 is 97.62% homologous to the sequence identified to uncultured archaeon clone ConP1-11F. Clearly, the predominant methanogen found to reside in the chicken ceca was M. woesei. By using a MPN enumeration method, methanogen counts were found to be in the range of 6.38 to 8.23 log10 organisms per gram wet weight. The 16S rDNA copy number per gram wet weight in the samples was between log10 5.50 and 7.19. The second phase of the study was conducted to observe the effects of selected nitrocompounds and two different feedstuffs on in vitro methane production in chicken