| Establishment of Paenibacillus genus is merely more than a decade before, Study on this genus in application of prevention and control of crop diseases and environment pollution is still in the initial stage, though with a broad developing space. Research shows species such as P. macerans,P. polymyxa and P. azoctoria are often considered dominant rhizosphere micro-organisms which promote plant growth and inhibit diseases.Endophyte Paenibacillus sp. Aloe-11 is an isolated bacterium from a strain of Chinese Aloe. Whole-genome sequencing analysis and Preliminary tests show its resemblance with Paenibacillus polymyxa:it has no pathogenicity to human, animals and plants; some strains produce multiple bioactive substances such as enzymes, antibacterial substances, plant hormones and flocculants et. al. This thesis applied Paenibacillus sp. Aloe-11 to animal samples in order to study its adhesion to the animal intestinal tract (colonization) and cellulose utilization of the animals ingested feed, prokaryotic expression theβ-1,3-1,4 glucanase gene as well as the impact on animal performance and the influence of intestinal flora and antibody titer. Research methods and results are as follows:1. Verificating ability of Paenibacillus sp. Aloe-11 to decompose ingested cellulose and prokaryotic expression theβ-1,3-1,4 glucanase gene. (i) the experimental group was treated with the basal diet and gavage of Paenibacillus sp. Aloe-11 viable cells while the control group is treated with basal diet only. The experimental group was daily fed with 1mL of fermented broth containing 2.2×108/mL viable cells approximately for 14 successive days. The mice were assayed for the cellulose decomposition rate in feces on days 3,7,14, and then ceased to be fed on Paenibacillus sp. Aloe-11 and tested for cellulose decomposition rate in feces on days 3,7,10,14. The result shows through oral administration Paenibacillus sp. Aloe-11 can survive and attach to the surface of the intestinal mucosa in mice and reach to 45.67% cellulose decomposition rate and 38.45% higher than control.The control group cellulose decomposition rate is 7.14%. There is significant difference in experimental group and cotrol group. (ii) Several endoglucanase (β-1,3-1,4 glucanase)genes were cloned to prokaryotic expression system for enzyme activity assay. The results showed low gene expression and enzyme activity ofβ-1,3-1,4 glucanase genes was 79u/mL.2. Determining the colonization site of Paenibacillus sp. Aloe-11 in amimal intestine, (i) Paenibacillus sp. Aloe-11 containing 2.2×108 bacteria/mL viable cells approximately mixed with water by 1:3. (ii) Mice and chicks were fed with Paenibacillus sp. Aloe-11 for 14 days and then detect the number of Paenibacillus sp. Aloe-11 mucosal surface of each intestinal segment on days 7,14, and 3,7,14,21 days after feeding of bacteria was ceased. The result indicates Paenibacillus sp. Aloe-11 can survive and attach to various sites certain percentage on the surface of the in twelve duodenum, jejunum, ileum, colon. Bacteria colonization in cecal more than the duodenum and jejunum. This may be due to the intestine near the stomach, the PH is lower, not suitable for bacterial survival. The results showed that colonization time during 14-21 days.(iii)Impaction of Paenibacillus sp. Aloe-11 on intestinal flora. (i) Mice and chicks were fed with Paenibacillus sp. Aloe-11 mixture for successive days. Mice and chicks were fed with Paenibacillus sp. Aloe-11 for 14 days and then detect the number of Paenibacillus sp. Aloe-11 mucosal surface of each intestinal segment on days 7,14, and 7 days after feeding of bacteria was ceased.then dissected to assay the number of aerobic and anaerobic bacteria, E. coli, Lactobacillus, Bifidobacterium, Enterococcus on intestinal surface and in intestinal contents. Result shows the numbers of aerobic and anaerobic bacteria, E. coli and Enterococcus are relatively lower than control group while the Lactobacillus and Bifidobacterium are higher. Paenibacillus sp. Aloe-11 can regulate the intestinal flora, inhibit harmful bacteria reproductive, promoting probiotics reproductive.3. The effect of Paenibacillus sp. Aloe-11 on animal production. (i) mice and 7-day old chicks were randomLy divided into two groups:groups fed on Paenibacillus sp. Aloe-11 fermentation broth and control groups. (ii) At 8 a.m.7,14,21,28,35,42,49 day-old mice and chickens were weighed without feeding and then calculated for average daily weight gain(ADG) and average weekly weight gain(AWG). The result shows in mice groups the daily gain is not greater when fed with Paenibacillus sp. Aloe-11 than controls, and the end weights show no significant differences. In chick groups both the average daily gain and end weights are greater in experimental group before 35 days and end weights show no significant differences..4. Exploring the effect of Paenibacillus sp. Aloe-11 on antibody titers. (i) the five day old chicks were randomLy divided into five groups:group fed with Paenibacillus sp. Alone-11 fermentation broth alone(group A); group inoculated with Lasota (IV lines) live attenuated vaccine and fed with Paenibacillus sp. Aloe-11 fermentation broth(group B),co-immunization group inoculated with both Paenibacillus sp. Aloe-11 polysaccharide extract and Newcastle disease of Lasota (IV lines) live attenuated vaccine(group C); high-temperature inactivation of the fermentation broth and Newcastle disease of Lasota (IV lines) live attenuated vaccine(group D);group inoculated with Lasota (IV lines) live attenuated vaccine immune(group E, control group); (ii) in co-immunization group Paenibacillus sp. Aloe-11 polysaccharide extract and Newcastle disease of Lasota (IV lines) live attenuated vaccine were mixed in same proportion and then inoculated into7-days chicks. Chicks were subjected to blood collection when given second inoculation 20 days after the first one.20 days after second inoculation, blood was collected for serum separation. The separated serum was treated with indirect hemagglutination inhibition test reaction for the determination of antibody potency. The immunization effect compared between each other. There is significantly different between experimental group.but it indicated no significantly different between the groups measured which is from the factory.This is the good effect of Newcastle disease immunization and Paenibacillus sp. Aloe-11 had no significant effect.Its effet on antibody titers is not clear. |
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