Isolation and identification of a cellulolytic bacterium from the Tibetan pig's intestine and investigation of its cellulase production

Background The Tibetan pig is a pig breed with excellent grazing characteristics indigenous to the Qinghai-Tibet plateau in China. Under conditions of barn feeding, 90% of its diet consists of forage grass, which helps meet its nutritional needs. The present study aimed to isolate and identify a cellulolytic bacterium from the Tibetan pig's intestine and investigate cellulase production by this bacterium. The study purpose is to provide a basic theory for the research and development of herbivore characteristics and to identify a source of probiotics from the Tibetan pig. Results A cellulolytic bacterium was isolated from a Tibetan pig's intestine and identified based on morphological, physiological, and biochemical characteristics as well as 16S rRNA analysis; it was designated Bacillus subtilis BY-2. Examination of its growth characteristics showed that its growth curve entered the logarithmic phase after 8-12 h and the stable growth phase being between 20 and 40 h. The best carbon source for fermentation was 1% corn flour, while 2% peptone and yeast powder compound were the best nitrogen sources. The initial pH during fermentation was 5.5, with 4% inoculum, resulting in a high and stable amount of enzyme in 24-48 h. Conclusions The isolated BY-2 strain rapidly grew and produced cellulase. We believe that BY-2 cellulase can help overcome the shortage of endogenous animal cellulase, improve the utilization rate of roughage, and provide strain sources for research on porcine probiotics.

Polymorphism of four microsatellites and their polymerisation effect on litter size in Boer goats

Background: Finding molecular markers linked to quantitative trait loci is the first step in marker-assisted selection (MAS). Microsatellites are excellent molecular markers because of their large numbers, even distribution in the genome, and high polymorphism. In this study, the polymerisation effect of four microsatellites (OarAE101, BM1329, BM143, and LSCV043) on litter size was analysed using microsatellite markers and pedigrees. Results: The results indicate that the polymerisation effect of four microsatellite loci significantly affected the litter size. E5E10F2F6G1G5H6H11 and E3E8F5F7G1G5H3H9 had the highest and lowest litter sizes in the F2 generation, respectively. The polymerisation effect value (v) of the E5E10 genotype was 3.18% higher than that of the E2E7 genotype. The v of genotype F2F6 was 14.47% higher than that of the F5F7 genotype. The v of genotype G1G5 was 58.99% higher than that of the G2G7 genotype. The v of the H6H11 genotype was 5.60% to 49.74% higher than those of the H4H10 and H1H7 genotypes. The v of the H3H9 genotype was 17.22% higher than that of the H1H7 genotype. Conclusions: The results of the present study are vital to improving the reproductive performance in goat breeds MAS.

A preferable approach to clone hLIF cDNA from the genomic DNA

Complementary DNA (cDNA) is valuable for investigating protein structure and function in the research of life science, but it is difficult to obtain by traditional reverse transcription. In this study, we employed a novel strategy to clone the human leukemia inhibitory factor (hLIF) gene cDNA from genomic DNA directly isolated from the mucous membrane of mouth. The hLIF sequence can be acquired within a few hours by means of amplification of each exon and splicing using overlap-PCR. Thus, the new approach developed in this study is simple, time- and cost-effective, and it is not limited to particular gene expression levels of each tissue.