Isolation And Identification Of Microbial From Liupao Tea And Study On The Influence Of Superiority Strains Of Tea Compounds

Liupao Tea is one of dark tea,produced from guangxi wuzhou,has the "red,heavy,stale,mellow" quality characteristics,owed to two "pile" and two high temperature steaming processes.The microbial have a vital role in the pile process and storage process of the Liupao Tea.Microbial can produce the enzymes to transformation of chemicals,affecting the quality and health care effect of the tea.But the current study on Liupao Tea microbial is little and not enough.22 strains were isolated from 12 different storage year and different factory of Liupao Tea samples isolated,and seven kinds of superiority strains were selected for liquid fermentation,and artificial inoculated to Liupao Tea for fermentation,the important chemical composition of fermentation tea liquor were determined,aim to explore the advantage bacterium effects on bioconversion of Liupao Tea.Through traditional methods to observe the colony strain morphological characteristics,using the optical microscope observation,combined with the molecular biology level of DNA identification,and through ITS sequence homology search,construct phylogenetic tree.8 genera and 20 species of microbes were obtained and identified,including 7 species of Aspergillus : Aspergillus tubingensi,Aspergillus niger,Aspergillus rube,Aspergillus pseudoglaucus,Aspergillus chevalieri,Aspergillus versicolor,Aspergillus sydowii;3 species of Penicillium: Penicillium jiangxiense,Penicillium griseofulvum,Penicillium sclerotiorum;1 specie of Eurotium: Eurotium amstelodami;3 species of saccharomyces: Rhodotorula mucilaginosa,Jaminaea angkoriensis,Blastobotrys raffinosifermentans;1 specie of Sphingosine: Sphingomonas sp.;3 species of Cladosporium: Cladosporium cladosporioides,Cladosporium uredinicola,Cladosporium oxysporum.1 specie of Cercospora:Cercospora capsicigena;1 specie of Bjerkandera:Bjerkandera adusta.The experiment concluded wuzhou tea factory and China Tea(Wuzhou)factory in the Liupao Tea kinds of microbial are very different,overall analysis,wuzhou factory tea microbial are quantity and variety,the China Tea(Wuzhou)factory is less,and in the store for 3,6,9 years almost separate micro-organisms,This shows that both factories in the processing technology and storage method has the very big difference.Advantage representative microbial were choosed: Eurotium amstelodami,Penicillium jiangxiense,Aspergillus tubingensi,Aspergillus niger,Penicillium griseofulvum,Rhodotorula mucilaginosa,Sphingomonas sp to fermentation liquid,tea polyphenols,flavonoids,amino acids,soluble sugar,tea pigment,caffeine and catechins content of fermented liquid were determined after cultivation of 48 h,96 h,144 h,192 h respectively.Results show that,in the before and after fermentation,Eurotium amstelodami,Penicillium jiangxiense,Aspergillus tubingensi,Aspergillus niger,Penicillium griseofulvum,their penicillium fermentation liquor of content of tea polyphenols,flavonoids,amino acids,soluble sugar content decreased with the extension of fermentation time,both compared with ck,all have significant difference(P < 0.05),content of tea polyphenol decreased by 47.14%,64.35%,59.42%,57.76%,59.42%.Content of theaflavins was increased and then after decreased first,thearubigins is the overall downward trend,theabrownin in the overall is upward trend.In Fermentating process,the mycelium proliferate,secrete a lot of tea polyphenol oxidase,protein hydrolase,starch hydrolysis enzyme etc,make the tea liquor is becoming more and more red;content of catechin fermented by Eurotium amstelodami,Penicillium jiangxiense fermentation liquor is declining,ester type significantly decreased(P < 0.0001),in the late fermentation,EGCG,GCG,ECG almost were undetectable,gallic acid and the non ester type catechins content is a trend of first increased after decreased;Caffeine content showed a trend of decline after rising first,compared with that of CK,has the extremely significant difference(P < 0.0001).Sphingomonas sp fungus compared with ck,the flavonoids content changes with significant difference(P < 0.05),the overall upward trend after fall first,other components changes have no significant difference(P < 0.05);Rhodotorula mucilaginosa during the fermentation process compared with the ck,on the content of soluble sugar,has a significant rise in phase,it has no effect on tea pigment.The results showed that the tested Liupao Tea had microbial diversity,mainly by Aspergillus and Penicillium genus and saccharomyces.Eurotium amstelodami,Penicillium jiangxiense,Aspergillus tubingensi,Aspergillus niger plays an important role of the biological transformation of Liupao Tea.The results will be useful to improve Liupao Tea processing,improve the quality,and to provide a theoretical foundation for the exploring the health care functions of Liupao Tea.