| In order to elucidate the interaction mechanism of solid state fermentation of astragalus by Lactobacillus plantarum and study its application effect on broilers,this study used solid state fermentation of Astragalus by Lactobacillus plantarum.Search Engine Marketing(SEM)was used to observe the effects of Lactobacillus plantarum on the apparent structure of Astragalus.Molecular weight changes of astragalus protein after fermentation were analyzed.The influence of astragalus on galactose gene expression in Lactobacillus plantarum was detected by Fluorescence quantitative PCR(Fluorescence quantitative pcr)and the reasons were analyzed.The content changes of astragalus polysaccharide after fermentation by Lactobacillus plantarum were detected,and the causes of such changes were analyzed.Based on High Performance Liquid Chromatography(SEM)technology,the changes in the main active components of Astragalus membranaceus after fermentation were determined by calycoisoflavones and formononetin,and the reasons for the changes were analyzed.In addition,solid fermented astragalus preparation was applied to broilers to observe the application effect on the production of broilers,observe the growth performance indexes of broilers,analyze the serum antioxidant indexes and immune indexes of broilers,observe the changes of intestinal villus height and crypt depth by paraffin section,and analyze the changes of intestinal short-chain fatty acids by using biogenic technology.The main results are as follows:(1)Solid state fermentation of Astragalus by Lactobacillus plantarum: The surface of unfermented Astragalus was found to be complete and sterile.After fermentation for 3 days,a small amount of Lactobacillus plantarum attached to the surface of astragalus,and the surface wooden structure was broken.Electrophoresis of Sodium Dodecyl Sulfate Poly Acrylamide Gel Electrophoresis,sodium dodecyl sulfate polyacrylamide gel electrophoresis,sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE found that after fermentation,the macromolecular protein in astragalus was degraded into small molecular protein and maintained at15 k Da.Fluorescence quantitative PCR showed that galactosidase in Lactobacillus plantarum was significantly increased after fermentation compared with before fermentation(P < 0.05).The changes of 13 polysaccharides in Astragalus were detected by gas chromatography-tandem mass spectrometry.Trehalose,lactose,L-fucose,inositol,L-rhamnose-d-sorbitol and xylitol were stable before and after fermentation.Maltose fermentation decreased to 0.79μg/m L.D-arabinose increased by 96.7% compared with that before fermentation;D-fructose increased gradually and reached 61.18μg/m L after fermentation for 3 days,then decreased and remained at 56.73μg/m L.Glucose peaked at 64.49μg/m L on the third day and then decreased gradually.The maximum value of D-galactose was 3.07μg/m L on the seventh day of fermentation.It was found by HPLC that the content of calycoflavone and formononetin in astragalus gradually increased under the action of bioenzyme in Lactobacillus plantarum,which increased by 45.23% and 38.36%,respectively,compared with that before fermentation.Based on the above results,the interaction between Lactobacillus plantarum and astragalus membranaceus was observed during solid fermentation.(2)Application of solid State Fermentation of Astragalus in broilers: A total of 120 3-day-old broilers were randomly divided into 4 groups.The control group was fed a basal diet,the astragalus group was fed 3% astragalus on the basis of the control group,the fermented astragalus group was fed 3% astragalus on the basis of the control group,and the probiotic group was fed 3%Lactobacillus plantarum on the basis of the control group.Compared with the control group,the astragalus group and the probiotics group,the growth performance of the fermented astragalus group increased by 24% compared with the control group;compared with the astragalus group,the growth performance of the fermented astragalus group increased by 16%;compared with the probiotics group,the growth performance of the broilers increased by 11%.It is proved that adding fermented astragalus in the diet can improve the growth performance of broilers.In terms of serum antioxidant indices,the serum TAOC activity in fermented Astragalus group was5.16nmol/m L,which was significantly higher than that in control group,Astragalus group and probiotics group(P<0.05).MDA content was 0.52 nmol/m L,which was significantly lower than that of control group,Astragalus group and bacterial solution group(P<0.05).The activities of SOD,GSH-Px and T-AOC in serum of chickens in fermented Astragalus group were335.33nmol/m L,19.93nmol/m L and 13.89nmol/m L,respectively.Compared with the other three groups,it was significantly higher(P<0.05);In terms of immune factors,Ig A content in fermentation group was 105.4μg/m L,which was significantly different from that in control group and probiotic group(P<0.05),but had no significant difference from that in astragalus group(P>0.05).Ig M in fermentation group was significantly increased compared with control group(P<0.05),but had no significant difference with astragalus group and probiotic group(P>0.05).Compared with the other three groups,Ig G fermentation group increased by 41.3%,45.5% and48.6%,respectively,with significant differences(P<0.05).There was no significant difference in IFN-γ between the fermentation group and the other three groups(P>0.05).There was no significant difference in IL-12 between the fermentation group and the other three groups(P>0.05).The IL-6 fermentation group was 19.9μg/m L,which was significantly different from the other three groups(P<0.05).In conclusion,Lactobacillus planplanum fermentation of Astragalus could increase Ig M and Ig G of chickens and reduce the content of serum IL-6 immune factors.By paraffin section,it was found that the villus height of the fermentation group was 16.28%,13.84%and 14.28% higher than that of the other three groups(P<0.05),and the crypt depth of the fermentation group was decreased by 30.86% and 25.87%,with significant differences(P<0.05),but there was no significant difference between the fermentation group and the bacterial liquid group(P>0.05).V/C was higher by 45.89%,38.73% and 31.28%,respectively(P<0.05).Targeted metabolomics analysis showed that propionic acid content of short-chain fatty acids in fermentation group was increased by 70.5%,54.7% and 74.3% compared with control group,Astragalus group and probiotic group,with significant differences(P<0.05).Acetic acid was increased by 53.2%,49.3% and 60.6% compared with the other three groups,and there were significant differences(P<0.05).Butyric acid was increased by 20.83%,29.2% and 18.6%,respectively,with significant difference(P<0.05).There was no significant difference between isobutyric acid and isovalerate acid(P>0.05).Compared with the other three groups,valerate control group was decreased by 25.8%,32.4% and 37.6%,respectively(P<0.05).Compared with the other three groups,acetic acid probiotics group decreased by 18.8%,23.3% and 28.3%,respectively,with significant difference(P<0.05).In conclusion,adding fermented Astragalus in the diet can improve the growth performance,improve the body’s immunity,and enhance the production of intestinal metabolites.The results showed that the cellulose and pectin on the surface of astragalus were decomposed effectively by solid fermentation with Lactobacillus plantarum,and the macromolecular proteins were degraded into small molecules.Astragalus could increase the galactosidase content in Lactobacillus plantarum.Solid fermentation increased the content of functional polysaccharides,calycoflavone and formononetin in astragalus.Fermented astragalus preparation could significantly improve performance,antioxidant and immune indices,intestinal morphology and short-chain fatty acid content of broilers.This study explored the interaction mechanism of Lactobacillus plantarum fermentation of astragalus,promoted the theoretical basis of traditional Chinese medicine fermentation,and provided a theoretical basis for promoting and applying the fermentation of Astragalus in broilers.. |
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