| Objective:This study was aimed to isolate and identify Acetobacter from Drosophila,and to investigate their roles in promoting the growth and Development of hosts.Methods:We Isolated of Acetobacter from Drosophila by selective culture medium,identified strains by Gram staining and 16 S rRNA gene alignment,observated the use of 4 kinds of carbon sources in the case of Acetobacter within 12 hours,and detected the fermentation characteristics in vitro.The number of bacteria in the intestinal tract of Drosophila was counted by the coated plate.The flies were randomly divided into three groups: convention rear(CR),germ free(GF)and Acetobacter orientalis.The effect of the bacteria on the development of Drosophila was determined by counting the average time of pupae and adults formation.The changes of surface area were detected by observing eggs after 0 days from the time of their formation in Drosophila to detect the growth rate of Drosophila.We dissected the gut of three groups of Drosophila,and counted the number of intestinal cells by PH3 staining.Extracted of the above three groups of Drosophila RNA,performed RT-PCR and detected the effect of strain in Drosophila hormone secretion.Results:1.The strain was identified as Acetobacter orientalis and gram negative which belonged to the Acetobacter.2.The growth rate of Acetobacter orientalis in 12 hours was as high as 1.25,and pH decreased to 3.8.3.The colonization number of intestinal in the different growth stages of Drosophila was as high as 104 and 105.The experimental results showed that the Acetobacter orientalis could clone in the intestinal of next generation of Drosophila,and the number of clone has reached 103.4.The group of Acetobacter orientalis was under the rich conditions(2% yeast),and the time of pupae and adult formation was 6.2 d and 10.1 d and there was no statistically significant comparison to CR groups(P > 0.05);There was statistically significant(P < 0.05)comparison to GF groups(7.8 d and 12.1 d).In the condition of lack of nutrition(0.25% yeast)case,The time of pupae and adult formation of the group of Acetobacter orientalis was 9 d and 13.3 d,and there was not statistically significant(P > 0.05)compared with CR;and compared with GF group(7.8 d and 22 d),the difference was statistically significant(P < 0.001),and the Acetobacter orientalis shorten the developmental period of Drosophila significantly,and even could replace the role of CR.The growth rate of the group was significantly higher than GF,and similar to CR.5.The PH3 staining experiments showed that the group of Acetobacter orientalis could promote intestinal cell proliferation of Drosophila than GF group,especially in the midgut of Drosophila(P < 0.001),the number of intestinal cell proliferation was more than that of CR group,which was statistically significant compared with CR group(P < 0.05).6.Prothoracicotropic hormone of Drosophila of Acetobacter orientalis secreted in earlier time,and the amount of secretion was higher compared with the GF group,the difference of high peak secretion between two groups was statistically significant(P < 0.01),and results were similar compared with CR group.7.The expression of insulin of Acetobacter orientalis was in the earlier stage and higher compared with the GF group.The different was statistically significant(P < 0.001),and the results were similar to the CR group(P < 0.01).Conclusion:In this study,the Acetobacter orientalis was isolated from the intestine of Drosophila.The Acetobacter orientalis was a kind of probiotics and symbiotic bacteria.Acetobacter orientalis could increase the growth rate and shorten the developmental period in Drosophila at the histological level and promoted intestinal cell proliferation at the cellular level.What's more,it could activate the insulin signaling pathway at the hormone level,which maintained the stable blood glucose level and promoted the metamorphosis during the key physiological period(from Drosophila larva to pupa).Finally,it can promote the growth and development of Drosophila. |
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