Chemical,Microbial And Metabolic Composition And Bioactivity Of TaiSui Cultured In Honey Solution

Tai Sui,shaped like meat or jelly,is a complex of myxomycetes,bacteria and fungi.Recently, with the further study of Tai Sui,its bioactivity is revealed and it can now be artificially cultured.In order to evaluate the characteristic and safety of artificially cultured Tai Sui(ac TS),and develop it into fermented food,functional food or oral liquid,the chemical components,microbial community,extracellular metabolites,anti-oxidant and anti-tumor of ac TS have been investigated in this study.Results showed that:(1)The concentrations of total carbohydrates,protein,fat,total ash and moisture of wet ac TS were 2.13±0.02 g/100 g,0.13±0.01 g/100 g,0.07±0.00 g/100 g,0.04±0.00 g/100 g and92.51±0.60 g/100 g,respectively.The concentrations of top three trace elements——K,Ca and P,are 1424.92±13.72 mg/kg,159.96±4.21 mg/kg and 67.89±0.15 mg/kg,respectively.The macroscopic morphology,microscopic structure and chemical structure of ac TS were similar to that of bacterial cellulose membrane.(2)The results of high-throughput sequencing showed that groups U(group upper),L(group lower)and M(group medium)of ac TS all contained bacteria,archaea and fungi.The species richness,diversity and community structure of bacteria and archaea in three groups were similar.The species richness and diversity of fungi in group L were significantly higher than those in the other two groups.And the community structure of fungi in group L was different from that in the other two groups.Proteobacteria,Euryarchaeota and Ascomycota were the dominant phyla of bacteria,archaea and fungi,respectively.Alcaligenes,Ochrobactrum and Lactobacillus were the dominant genera of bacteria;Methanosaeta,Methanosphaera and Natronomonas,the dominant genera of archaea;Zygosaccharomyces,Mortierella and Fusarium,the dominant genera of fungi.Four strains were obtained by plate purification,which were identified as Paenibacillus chibensis,Sphingomonas pseudosanguinis strain JGTA-S6,Gluconacetobacter intermedius and Zygosac-charomyces bisporus.And G.intermedius could produce bacterial cellulose.(3)After culturing in honey solution,the concentrations of 311 metabolites,such as amino acids and nucleotides,were increased,among which the most varied was citric acid(256.01±39.57times),and the least was kahamol(2.20±0.12 times).The increased metabolites involved most KEGG pathways and were mainly related to 5 pathways such as environmental information processing,metabolism and organismal systems.Most of the metabolites were beneficial to human beings,playing an important role in improving the color and flavor of food,preventing food spoilage,strengthening nutrition,anti-tumor,anti-oxidation and other aspects.Some metabolites were correlated with microorganisms,such as Lactobacillus and D-glucuronate-1,5-lactone were significantly(p<0.05)positively correlated,Aspergillus and desthiobiotin were significantly(p<0.05).(4)The culture of ac TS had high DPPH scavenging ability and reducing ability,medium·O^2- scavenging ability and weak·OH scavenging ability.The culture of ac TS had a strong inhibition effect on Hela cells and Hep G2 cells under the original p H condition,and a weak inhibition effect under the condition of p H 7.0.The culture of ac TS had a strong effect to protect Hela cells and Hep G2 cells from oxidative damage caused by 10 mmol/L H₂O₂.Under the original p H condition,the culture of ac TS had an inhibition effect on macrophages RAW264.7,and had a weak effect on the proliferation of macrophages under the condition of p H 7.0.The culture of ac TS had the ability to protect macrophages from oxidative damage caused by 10 mmol/L H₂O₂.Under these two p H conditions,the culture of ac TS could not effectively improve the phagocytic capacity of macrophages.In conclusion,ac TS is not a good source of macro nutrients and trace elements,whilst the chemical structure of ac TS and the safety of some microorganisms in ac TS is also unknown.Nevertheless,it is a good source of cellulose-producing strains,and it provides some probiotics and beneficial metabolites for human,and it has certain antioxidant capacity.So,it is possible to develop ac TS into functional food when the safety of ac TS is proved.