Screening and identification of fibrinolytic enzyme-producing microbes in fermentation process of Sojae Semen Praeparatum / 中草药

Objective: To screen and identify the dominant strains which produce fibrinolytic enzyme during the processing of Sojae Semen Praeparatum (SSP, Dandouchi in Chinese). Methods: SSP was prepared according to the Chinese Pharmacopoeia (2020 edition), and samples were taken at different time points during the fermenting process of SSP.The casein plate method and fibrin plate method were used to screen the fibrinolytic enzyme-producing microorganisms in samples at different time points. The fibrinolytic enzyme-producing microorganisms were inoculated in the designated liquid medium to obtain single strain fermentation broth, and fibrin plate method was used to measure the fibrinolytic activity of the fermentation broth. The DNA sequences of fibrinolytic enzyme-producing bacteria and fungi were amplified using 16S rDNA and 18S rDNA universal primer by PCR respectively.The amplified products were sequenced, and the sequencing results were identified through NCBI homology comparison. Molecular biological identification was done by phylogenetic tree constructed by MEGA 4.1 software. Results: Three types of fibrinolytic enzyme-producing bacteria were screened out and identified in this study. They were Bacillus subtilis, Stenotrophomonas maltophilia and Micrococcus, respectively. The result of fibrin plate method showed that the fermentation broth of S. maltophilia had the highest fibrinolytic activity, reaching 527.49 IU/mL. Conclusion: There are fibrinolytic enzyme-producing dominant microorganisms existing in the fermenting process of SSP and the thrombolytic effect of SSP is worthy of further study. This study lays the foundation for revealing the formation mechanism of fibrinolytic enzyme in the fermentation process of SSP.

Investigation of microbial community involved in fermentation of Massa Medicata Fermentata / 中国中药杂志

This study aimed to clarify the microbial diversity, dominant species and the change of community structures in the fermentation of Liushenqu(Massa Medicata Fermentata), and explore the material foundation of its pharmacodynamics effect. On the basis of standardizing the fermentation process, Massa Medicata Fermentata was prepared by screening and optimizing the recipes and the standard formula issued by the Ministry. The community structure and growth process of fungi and bacteria in the samples at five time points(0, 17, 41, 48, 65 h) in the fermentation process of Massa Medicata Fermentata were analyzed by using isolation and culture of eight different media and high-throughput DNA sequencing technology. The results indicated that the samples of the two recipes pre-sented high microbial diversity at the initial fermentation stage, with Aspergillus spp. as the dominant species. As the fermentation process goes forward, Saccharomycopsis fibuligera and Rhizopus oryzae soon became dominant species from 17 h after fermentation commencement point to the fermentation end, while the other species were inhibited at a lower level from 17 h. The species diversity of bacteria in the initial fermentation samples was also high, and Enterobacter was the dominant species. Enterobacter cloacae, Pediococcus pentosaceus and Cronobacter sakazakii became dominant bacterial species 17 h after fermentation commencement, while the species diversity was decreased. Our results will be a scientific basis for promoting the fermentation process of Massa Medicata Fermentata by using pure microbial cultures.

Preliminary Research on Dynamic Change of Microbial Population in Fermentation Process of Pinelliae Rhizoma Fermentata / 中国实验方剂学杂志

Objective:To detect the colony number of bacteria, yeasts and molds in fermentation process of Pinelliae Rhizoma Fermentata (PRF), microbial flora species, and quantitatively analyze the dynamic changes of four dominant microorganisms at different fermentation time points of PRF, so as to provide experimental basis for exploring the processing mechanism of PRF. Method:According to Pharmaceutical Standard Preparation of Traditional Chinese Medicine Prescription of Ministry of Health of the People's Republic of China (the 10th volume), PRF was processed. The samples at five different fermentation time points (0, 30, 60, 90, 120 h) of PRF were taken, the culturing, isolation and purification of bacteria, yeasts and molds were carried out with selective media, and the colonies were counted. Fluorescence quantitative polymerase chain reaction (PCR) technique was employed to conduct absolute quantification of Bacillus subtilis, Paecilomyces variotii, Byssochlamys spectabilis and Aspergillus niger. The recombinant plasmids of these 4 microorganisms were used as the standard substances, and the standard curves were prepared after dilution of multiple ratios, quantitative analysis was performed on these 4 microorganisms in five samples at different processing time points (0, 30, 60, 90, 120 h) of PRF. Result:During the fermentation process of PRF, the number of bacteria was low with smooth change, while molds and yeasts grew dramatically at the late stage of fermentation and reached 1×106 CFU·mL-1 at the end of fermentation. At 5 different fermentation time points, the copy numbers of Bacillus subtilis were 3.53×105, 7.56×104, 1.58×105, 1.90×106, 1.85×106 copies·g-1, the copy numbers of Paecilomyces variotii were 0, 0, 0, 3.45×107, 4.15×108 copies·g-1, the copy numbers of Byssochlamys spectabilis were 0, 0, 0, 1.04×108, 2.28×108 copies·g-1, the copy numbers of Aspergillus niger were 0, 0, 9.48×105, 1.47×106, 7.56×106 copies·g-1, respectively. Conclusion:The change trend of microflora in the fermentation process of PRF can be reflected by the dynamic change of four dominant microorganisms, and molds may play an important role in the processing of PRF. Fluorescence quantitative PCR technique has the advantages of rapidity, sensitivity, good repeatability and high specificity, it is suitable for exploring processing mechanism of PRF.

Physiological and biochemical characteristics of four dominant microbes and content of yellow pigment in fermentation process of Pinelliae Rhizoma Fermentata / 中草药

Objective: To study the physiological and biochemical characteristics of four dominant microorganisms and the yellow pigment content of Pinelliae Rhizoma Fermentata (PRF), and provide basis for exploring the mechanism of PRF processing. Methods: The optimum growth temperature and pH value of the four dominant microorganisms Bacillus subtilis, Paecilomyces variotii, Byssochlamys spectabilis, and Aspergillus niger were studied. The ability of producing acidase, amylase, protease, and yellow pigment were determined. The yellow pigment content of each sample at different fermentation time points in process of PRF was determined. Results: The most suitable growth temperatures for B. subtilis, P. variotii, B. spectabilis, and A. niger were 35 ℃, 29 ℃, 29-31 ℃, and 39 ℃; And the optimum pH were 7.0, 7.0, 7.5, and 7.0, respectively. Four kinds of microorganisms had the ability to produce amylase and protease. P. variotii and B. spectabilis had the ability to produce yellow pigment. The content of yellow pigment were 69.875, 69.875, 71.750, 119.500, and 137.875 μg/g in the samples at different time points. Conclusion: Four kinds of dominant microorganisms may play an important role in fermentation process of PRF.

Screening and identification of GABA-producing microbes in fermentation process of Sojae Semen Praeparatum / 中国中药杂志

A high-content GABA was found in Sojae Semen Praeparatum(SSP), which is a famous traditional Chinese medicine and officially listed in Chinese Pharmacopoeia. To screen out and identify GABA-producing microbes from samples at different time points during the fermenting process of SSP, traditional microbiological methods combined with molecular biological methods were used to study the predominant GABA-producing microorganisms existing in the fermenting process of SSP. This study would lay a foundation for further studying the processing mechanism of SSP. The fermenting process of SSP was based on Chinese Pharmacopoeia(2010 edition), and samples were taken at different time points during the fermenting process of SSP. The bacteria and fungi from samples at different time points in the fermenting process of SSP were cultured, isolated and purified by selective medium, and dominant strains were selected. The dominant bacteria were cultured in the designated liquid medium to prepare the fermentation broths, and GABA in the fermentation broth was qualitatively screened out by thin-layer chromatography. The microbial fermentation broth with GABA spots in the primary screening was quantitatively detected by online pre-column derivatization and high performance liquid chromatography established in our laboratory. GABA-producing microorganisms were screened out from predominant strains, and their GABA contents in fermentation broth were determined. The DNA sequences of GABA-producing bacteria and fungi were amplified using 16S rDNA and 18S rDNA sequences by PCR respectively. The amplified products were sequenced, and the sequencing results were identified through NCBI homology comparison. Molecular biological identification was made by phylogenetic tree constructed by MEGA 7.0 software. Through the homology comparison of NCBI and the construction of phylogenetic tree by MEGA 7.0 software, nine GABA-producing microorganisms were screened out and identified in this study. They were Bacillus subtilis, Enterococcus faecium, E. avium, Aspergillus tamarii, A. flavus, A. niger, Cladosporium tenuissimum, Penicillium citrinum and Phanerochaete sordida respectively. For the first time, nine GABA-producing microorganisms were screened out and identified in the samples at different time points during the fermenting process of SSP in this study. The results indicated that multiple predominant GABA-producing microorganisms exist in the fermenting process of SSP and may play an important role in the formation of GABA.