Research On The Diversity And Carbohydrate Metabolism Characteristics Of Lactic Acid Bacteria In Bee Intestines

There are a large number of microbes inhabiting the bee guts.Among them,lactic acid bacteria are the most abundant bacterial community.They form a complex symbiotic relationship with the host,which can help the host digest food,provide essential nutrients,decompose toxic components,and resist disease.Bacteria can also regulate the growth and development of the host and play an important role in the health of the host.During honey brewing,the flora in the gut of bees also affects the flora in the honey.As an important bee product,honey has many benefits to the human body.Studies have shown that honey can promote the growth of beneficial bacteria in the intestines,confirming the potential of honey as a prebiotic food.Honey is rich in a variety of beneficial components to the human body.Many of these beneficial components are produced by the lactic acid bacteria symbionts in honey.Therefore,research on the lactic acid bacteria in the intestines of bees and honey can provide a theoretical basis for the probiotic effects of honey.At the same time,it provides a preliminary research foundation for the development of lactic acid bacteria and its application in food.This study took the microbes in the bee guts and honey as the object.First,the microorganisms in different parts of the worker bee guts were separated and identified using traditional culture methods,and the diversity and function of the intestinal flora of bees were analyzed by metagenomic sequencing.Secondly,use the third-generation sequencing technology to analyze the diversity of the flora in honey,and explore the relationship between the diversity of the flora in the bees intestine and honey.Finally,the sugar metabolism analysis and metabolites determination of lactic acid bacteria coexisting in bee intestines and honey were carried out,and the influence on beneficial components in honey was explored,so as to provide theoretical reference for further exploring the function of lactic acid bacteria in bee intestines and honey and its potential application in the food industry.The results were as follows:(1)The dominant bacteria that can cultivate microorganisms in bee intestines and honey are lactic acid bacteria.207 colonies were obtained through cultivation,which can be divided into 3phyla,11 genera and 28 species.Among them,Lactobacillus(36.26%)and Lactobacillus plantarum(14.04%)were the dominant genus and species in bee guts.Lactobacillus(77.78%)and Lactobacillus kunkeei(50.00%)were the dominant genus and species in honey.(2)The overall dominant phyla,genera,and species of the intestinal tract were Proteobacteria(38.5%),Lactobacillus(34.9%)and Gillianella apicola(23.9%).The results of diversity analysis showed that there were differences in the flora of different parts of the intestine.Among them,the lactic acid bacteria were mainly concentrated in the crop and hindgut.The diversity of lactic acid bacteria in the hindgut was significantly higher than that of the crop.(3)Based on the KEGG protein functional annotation analysis of the function of the intestinal flora of bees,the intestinal flora of bees is mainly involved in host metabolism,genetic information processing and environmenta l information processing.Among them,carbohydrate metabolism in the metabolic process is annotated to the most proteins.The glycoside hydrolase was further studied.It was found that its main activity was hydrolysis of complex polysaccharides such as cellulose and peptidoglycan.At the same time,it was found that the hindgut samples with a large number of lactic acid bacteria enriched the most carbohydrate metabolic pathways.(4)The flora distribution characteristics of different honey samples were different.The flora diversity of dilute honey sample was low,and L.kunkeei was the dominant species.The flora diversity of dilute honey sample in colony 2 was higher than that in colony 1.The diversity of lactic acid bacteria in the mature honey samples was higher than that in the dilute honey samples,but the relative abundance of lactic acid bacteria was lower.(5)The six strains of lactic acid bacteria in bee intestines and honey samples had certain ability of sugar metabolism and antibiotic sensitivity.The results of polysaccharide metabolism in honey showed that the six strains of lactic acid bacteria had strong ability to utilize sucrose,trehalose and fructose,but weak or unable to utilize maltose and lactose.The organic acids produced by the strain with honey as carbon source mainly include lactic acid,acetic acid and citric acid,which have probiotic effect on human body.The results of antibiotic sensitivity evaluation showed that except some strains had inherent resistance to antibiotics,others were sensitive to antibiotics,which preliminarily verified the safety of the strains.(6)Carbohydrate metabolism of lactic acid bacteria was further analyzed through gene function annotation.Six bacteria have annotated more genes in amino sugar and riboside sugar metabolism,galactose metabolism,glycolytic gluconeogenesis,and pyruvate metabolism.This result proves from the genetic level that lactic acid bacteria can use carbohydrates in honey to produce beneficial components,which has application value.