Variation and interaction mechanism between active components in Rheum officinale and rhizosphere soil microorganisms under drought stress / 中国中药杂志

To explore the changes and the reaction mechanisms between soil microecological environment and the content of secon-dary metabolites of plants under water deficit, this study carried out a pot experiment on the 3-leaf stage seedlings of Rheum officinale to analyze their response mechanism under different drought gradients(normal water supply, mild, moderate, and severe drought). The results indicated that the content of flavonoids, phenols, terpenoids, and alkaloids in the root of R. officinale varied greatly under drought stresses. Under mild drought stress, the content of substances mentioned above was comparatively high, and the content of rutin, emodin, gallic acid, and(+)-catechin hydrate in the root significantly increased. The content of rutin, emodin, and gallic acid under severe drought stress was significantly lower than that under normal water supply. The number of species, Shannon diversity index, richness index, and Simpson index of bacteria in the rhizosphere soil were significantly higher than those in blank soil, and the number of microbial species and richness index decreased significantly with the aggravation of drought stresses. In the context of water deficit, Cyanophyta, Firmicutes, Actinobacteria, Chloroflexi, Gemmatimonadetes, Streptomyces, and Actinomyces were the dominant bacteria in the rhizosphere of R. officinale. The relative content of rutin and emodin in the root of R. officinale was positively correlated with the relative abundance of Cyanophyta and Firmicutes, and the relative content of(+)-catechin hydrate and(-)-epicatechin gallate was positively correlated with the relative abundance of Bacteroidetes and Firmicutes. In conclusion, appropriate drought stress can increase the content of secondary metabolites of R. officinale from physiological induction and the increase in the association with beneficial microbe.

Screening and Enzymatic Activity Analysis of Dominant Fermentive Bacteria of Sojae Semen Praeparatum from Different Production Places / 中国药房

OBJECTIVE:To provide reference for the standardized production of Sojae semen praeparatum (SSP). METH-ODS:SSP samples from Heilongjiang,Hebei,Gansu,Shandong,Anhui and Yunnan were respectively collected. The fermentive bacteria were cultured with the selective medium contained artemisiae annuae herba and mori folium. Foline-phenol method,fibrous protein plate method and p-nitrophenol-β-D-glucoside colorimetric method were respectively conducted to determine the activities of protease,plasmin and β-glucosidase of the strains to screen dominant fermentive bacteria. RESULTS:Totally 14 wild strains were separated from SSP samples from 6 production places, including 3 strains of bacteria and 11 strains of molds. 1 strain of rod-shaped bacteria and 1 strain of Mucor sp. were separated from SSP from Heilongjiang;2 strains of Mucor sp. and 1 strain of rod-shaped bacteria were separated from SSP from Hebei;1 strain of Mucor sp.,1 strain of Penicillium sp.,1 strain of Streptococ-cus sp. and 1 strain of Aspergillus sp. were separated from SSP from Gansu;2 strains of Mucor sp. were separated from SSP from Shandong;1 strain of Mucor sp. and 1 strain of Aspergillus sp. were separated from SSP from Anhui;and only 1 strain of Mucor sp. was separated from SSP from Yunnan. According to the strains category and enzyme activities,No.1 bacillus,No.9 Aspergillus sp.,No.11 and No.14 Mucor sp. were preliminary authenticated as dominant fermentation microorganism,total enzyme activities of the 4 strains were 22.77,25.49,41.32,39.13 U/g respectively. CONCLUSIONS:The fermentive bacteria of SSP from different pro-duction places were different,and the dominant one can be screened preliminary through enzyme activity analysis.

Identification and AHLs Detection of Dominant Bacterium of Sea Cucumber (Apostichopus japonic) Infected with the Skin Ulceration Syndrom / 微生物学通报

The skin ulceration syndrome of sea cucumber is a kind of desease induced by bacterium.In order to investigate the bacterium of infected sea cucumber and detect the N-acyl-homoserine lactones(AHLs) se-cretion of the bacterium,7 bacterial strains were isolated from the infected sea cucumber.These strains were identified by physiological-biochemical characteristics and 16S rDNA sequence.Results show that strain C6 belongs to Tenacibaculum,strain 4 belongs to Shewanella putrefaciens group,strain TB belongs to Vibrio,strain BP2,BP3,BP4 and BP6 belong to Pseudoalteromonas,respectively.AHLs were detected with strain Agrobacterium tumefaciens KYC55.Among these bacterial strains,strain C6,4,TB,BP3 and BP4 can se-cret AHLs,while strain BP2 and BP6 can’t.And the AHLs activity differs,from the highest to the lowest are 4,TB,BP4,BP3 and C6.

Study on Biologic-Ecological Restoration for Eutrophication Water / 环境与健康杂志

Objective To find the dominant bacteria in mountain-lake water which can inhibit the alga growth by separation, culture,identification.Methods The samples from the lake in Simian Mountain area,Chongqing were collected.Bacteria- increasing culture,separation and identification were conducted to choice the dominant bacteria.With the dominant bacteria,the ecological restoration was conducted in the eutrophicated water in laboratory,the growth of alga was observed and the water quality was determined.Results Citrobacter freundi,Pseudomonas mendocina,Aeromonas veronii,Achromobaeter xylosoxidans were the dominant bacteria in the lake in Simian Mountain area,Chongqing.Compared with the blank water eontrol,the algae growth speed was slower,COD_(Mn)was 7.1 and 7.4 mg/L respectively,the chroma was both 20 degree in the experimental water samples with Citrobacter freundii and Pseudomonas mendocina.Conclusion The algae inhibitory action of Citrobacter freundii and Pseudomonas mendocina in the mountain lake water is obvious.