[Nitrogen Metabolism and Flora Characteristics of Bacteria Algae Complex System].

In order to denitrify the urban tail water deeply and control the eutrophication of surface water, the molecular biology methods were used to study the nitrogen metabolism performance of the denitrification complex flora and the algal-bacteria symbiotic system. The results showed that the nitrogen metabolism complex flora was high ammonification and denitrification performance. The removal effect of ammonia nitrogen of group JZ was very well in urban tailwater, and the degradation rate was as high as 95%. The removal effect of total nitrogen of group JZ was better than that of group J in the experimental water distribution. High-throughput sequencing showed that the main dominant flora and proportion of group J were Firmicutes 44.53%, Proteobacteria 43.41%, Actinobacteria 5.37%, Bacteroidetes 3.04%, and Chloroflexi 1.35%. The main dominant bacterial groups in the group JZ were 33.89% Cyanobacteria, 25.34% Chloroflexi, 19.38% Proteobacteria, 10.02% Firmicutes, and 4.20% Acidobacteria. The dominant species in group J were compared with those in group JZ; the proportions were 82% and 18% in Firmicutes, 69% and 31% in Proteobacteria, 1% and 99% in Cyanobacteria, 5.1% and 95% in Chloroflexi, 73% and 27% in Actinobacteria. It was concluded that the removal effect of ammonia nitrogen of group JZ was high in the urban tailwater. With the addition and growth of Micrococcus in group J, the nitrogen metabolism flora in group JZ changed accordingly, so as to adapt to the environment in which the dominant algae formed. It forms a new nitrogen metabolism system of bacteria and algae with Micrococcus. This research provides a theoretical and data basis for the application of algal-bacterial co-metabolism systems.

The impact of utilizing oyster shell soil conditioner on the growth of tomato plants and the composition of inter-root soil bacterial communities in an acidic soil environment.

Introduction: The objective of this study is to examine the impact of various oyster shell soil conditioners, which are primarily composed of oyster shells, on the growth of tomatoes in acidic soil. Moreover, the aim of this investigation is to analyze the variety and structure of soil bacterial populations in close proximity to tomato roots while also contributing to the understanding of the physical, chemical, and biological mechanisms of oyster shell soil conditioners. Methods: Tomato plants were grown in acidic red soil in three groups: a control group and a treatment group that used two types of oyster shell soil conditioners, OS (oyster shell powder) and OSF (oyster shell powder with organic microbial fertilizer). A range of soil physicochemical properties were measured to study differences in inter-soil physicochemical parameters and the growth of tomato plantings. In addition, this study utilized the CTAB (Cetyltrimethylammonium Bromide) technique to extract DNA from the soil in order to investigate the effects of oyster shell soil conditioner on the composition and diversity of bacterial populations. Utilizing high-throughput sequencing technologies and diversity index analysis, the composition and diversity of bacterial populations in the soil adjacent to plant roots were then evaluated. Ultimately, correlation analysis was used in this study to explore the relationship between environmental factors and the relative abundance of soil bacteria in the inter-root zone of tomato plants. Results: The findings indicated that the oyster shell soil conditioners were capable of modifying the physicochemical characteristics of the soil. This was evidenced by significant increases in soil total nitrogen (16.2 and 59.9%), soil total carbon (25.8 and 27.7%), pH (56.9 and 55.8%), and electrical conductivity (377.5 and 311.7%) in the OS and OSF groups, respectively, compared to the control group (p < 0.05). Additionally, data pertaining to tomato seed germination and seedling growth biomass demonstrated that both oyster shell soil conditioners facilitated the germination of tomato seeds and the growth of seedlings in an acidic red clay soil (p < 0.05). On the other hand, the application of two oyster shell soil conditioners resulted in a modest reduction in the diversity of inter-root soil bacteria in tomato plants. Specifically, the group treated with OSF exhibited the most substantial fall in the diversity index, which was 13.6% lower compared to the control group. The investigation carried out on the soil between tomato plant roots yielded findings about the identification of the ten most abundant phyla. These phyla together represented 91.00-97.64% of the overall abundance. In the inter-root soil of tomatoes, a study identified four major phyla, namely Proteobacteria, Bacteroidetes, Acidobacteria, and Actinobacteria, which collectively accounted for up to 85% of the total abundance. At the general level, the relative abundance of Massilia increased by 2.18 and 7.93%, Brevundimonas by 5.43 and 3.01%, and Lysobacter by 3.12 and 7.49% in the OS and OSF groups, respectively, compared to the control group. However, the pathogenic bacteria unidentified_Burkholderiaceae decreased by 5.76 and 5.05%, respectively. The correlation analysis yielded conclusive evidence indicating that, which involved the use of CCA (Canonical Correlation Analysis) graphs and Spearman correlation coefficients, pH exhibited a positive correlation (p < 0.05) with Shewanella and a negative correlation (p < 0.05) with Bradyrhizobium. The relative abundance of Lysobacter and Massilia exhibited a positive correlation with the levels of total soil nitrogen. Discussion: The utilization of oyster shell soil conditioner on acidic red soil resulted in several positive effects. Firstly, it raised the pH level of the inter-root soil of tomato plants, which is typically acidic. This pH adjustment facilitated the germination of tomato seeds and promoted the growth of seedlings. In addition, the application of oyster shell soil conditioner resulted in changes in the structure of the bacterial community in the inter-root soil, leading to an increase in the relative abundance of Proteobacteria and Bacteroidetes and a decrease in the relative abundance of Acidobacteria. Furthermore, this treatment fostered the proliferation of genera of beneficial bacteria like Massilia, Brevundimonas, and Lysobacter, ultimately enhancing the fertility of the red soil.

Analyzing the effect of storage conditions on anammox recovery performance from the perspectives of time, temperature and biomass form.

In this study, the effects of different storage conditions, such as temperature, storage time and biomass form, on the properties of anaerobic ammonia oxidation (anammox) were investigated along with the identification of the process mechanism. The results showed that the influence of storage time on anammox properties was stronger than that of storage temperature and biomass form. Also, the anammox recovery activity at 15 °C was better than that at 4 °C, and the anammox recovery activity of immobilized filler was better than that of anammox granular sludge (AnGS). Although cryogenic storage severely damaged anammox activity, lower loss of extracellular polymeric substances maintained the AnGS structure. The maximum recovery of specific anammox activity at 15 °C for the immobilized filler was observed to be 109%. In addition, intermittent substrate supplementation weakened the adverse effect of long-term storage on anammox activity, and was conducive to maintaining stable flora composition and promoting regeneration of anammox bacteria (AnAOB). High-throughput sequencing analysis showed that starvation resulted in increased community diversity, and the functional bacteria Candidatus Brocadia was observed to be more tolerant to starvation than Candidatus Kuenenia. Finally, principal component analysis was used to explain the complex relationship between process performance and preservation conditions. Based on the results of this work, it is recommended to preserve AnAOB in the form of immobilized filler at 15 °C and supplement substrate intermittently during long term storage. This study provides an economical and robust strategy for the short-term and long-term preservation of AnAOB.

Effects of sludge morphology on the anammox process: Analysis from the perspectives of performance, structure, and microbial community.

The nitrogen removal characteristics, physicochemical properties, and microbial community composition of four different anaerobic ammonium oxidation (anammox) sludge morphologies were investigated. The morphologies considered in this study, namely suspended sludge (Rs), biofilm (Rm), granular sludge (Rg), and encapsulated biomass (Re), were prepared from floc sludge. The results show that Re exhibited the maximum anammox activity, followed by Rg, Rm, and Rs. Additionally, the anammox contribution rate was higher in Rg and Re. The higher extracellular polymer content in Rg promoted sludge accumulation, and tryptophan was observed in Rm and Rg, which was replaced by humic acids in Rs. Re showed the largest specific surface area, hydrophobicity and strength, and its good structure ensured enrichment of anammox bacteria (AnAOB). In terms of the microbial community, the functional bacterium Candidatus Kuenenia accounted for the highest proportion in Rm (39.27%), but the presence of both anaerobic and aerobic regions led to increased community complexity with more nitrifying bacteria. In contrast, Rg and Re had a more specific microbial community. In addition, denitrifying bacteria tended to grow in Rs, while nitrifying bacteria were retained in Rm. The AnAOB were more likely to be enriched in sludge aggregates (both Rm and Rg) and carriers (Re). Through correlation analysis, the potential relationship involving bacterial flora evolution of each sample was clarified. Finally, the structural models of different morphologies of sludge were proposed. This study deepens the understanding of various anammox sludge morphologies as well as provides useful information for the cultivation of AnAOB and further application of anammox.

Ruminal Microbes Exhibit a Robust Circadian Rhythm and Are Sensitive to Melatonin.

Gut hormones are not only able to regulate digestive, absorptive, and immune mechanisms of the intestine through biological rhythms, but impact the host through their interactions with intestinal microorganisms. Whether hormones in ruminal fluid have an association with the ruminal ecology is unknown. Objectives of the study were to examine relationships between the diurnal change in ruminal hormones and microbiota in lactating cows, and their associations in vivo and in vitro. For the in vivo study, six cows of similar weight (566.8 ± 19.6 kg), parity (3.0 ± 0.0), and milk performance (8,398.7 ± 1,392.9 kg/y) were used. They were adapted to natural light for 2 weeks before sampling and fed twice daily at 07:00 a.m. and 14:00 p.m. Serum, saliva, and ruminal fluid samples were collected at 02:00, 10:00, and 18:00 on the first day and 06:00, 14:00, and 22:00 on the second day of the experimental period. The concentrations of melatonin (MLT), growth hormone (GH), and prolactin (PRL) were measured via radioimmunoassay, whereas amplicon sequencing data were used to analyze relative abundance of microbiota in ruminal fluid. JTK_CYCLE analysis was performed to analyze circadian rhythms of hormone concentrations as well as the relative abundance of microbiota. For the in vitro study, exogenous MLT (9 ng) was added into ruminal fluid incubations to investigate the impacts of MLT on ruminal microbiota. The results not only showed that rumen fluid contains MLT, but the diurnal variation of MLT and the relative abundance of 9% of total rumen bacterial operational taxonomic units (OTUs) follow a circadian rhythm. Although GH and PRL were also detected in ruminal fluid, there was no obvious circadian rhythm in their concentrations. Ruminal MLT was closely associated with Muribaculaceae, Succinivibrionaceae, Veillonellaceae, and Prevotellaceae families in vivo. In vitro, these families were significantly influenced by melatonin treatment, as melatonin treatment increased the relative abundance of families Prevotellaceae, Muribaculaceae while it reduced the relative abundance of Succinivibrionaceae, Veillonellaceae. Collectively, ruminal microbes appear to maintain a circadian rhythm that is associated with the profiles of melatonin. As such, data suggest that secretion of melatonin into the rumen could play a role in host-microbe interactions in ruminants.

Effect of Gegen Qinliantang on Structure of Intestinal Flora in Dysbacterial Diarrhea Rats Based on 16S rRNA Sequencing / 中国实验方剂学杂志

Objective:To study the effect of Gegen Qinliantang （GQT） on the structure of intestinal flora in dysbacterial diarrhea rats by 16S rRNA sequencing. Method:Sixty healthy SD rats were randomly and equally divided into a control group， a model group， high-， medium-， and low-dose GQT groups， and a Bifidobiogen group. The rat model was induced in the five groups except the control group by administration of mixed antibiotics （178.6 mg·kg^-1 cefradine and 31.25 mg·kg^-1gentamicin sulfate） according to the dose. Drug intervention was carried out in each group （7.02， 3.51， and 1.755 g·kg^-1 GQT for the high-， medium-， and low-dose GQT groups， 0.125 g·kg^-1 bifidobacterium capsules for the Bifidobiogen group， and sterile distilled water for the control and model groups） with a volume of 10 mL·kg^-1 for seven days. Colon contents of rats were obtained under anesthesia. The extracted fecal DNA underwent 16S rRNA high-throughput sequencing and the results were analyzed. Result:GQT was proved capable of adjusting the species number and Alpha and Beta diversity， improving the biological richness and diversity of the flora， and positively regulating three differential phyla （Firmicutes， Proteobacteria， and Bacteroidetes） and 14 differential genera （<italic>Bacteroides</italic>，<italic> Parabacteroides</italic>，<italic> Blautia</italic>， etc.） in rat model of dysbacterial diarrhea. Conclusion:The present study confirmed the regulatory effect of GQT on intestinal flora of dysbacterial diarrhea rats， and revealed the physiological and pathological mechanism between intestinal flora and dysbacterial diarrhea.

Diversity of microbiota composition of traditional Chinese medicine of Faeces Trogopterori from Shangluo, Shanxi province by sequence of the bacterial 16S rRNA gene / 药学学报

To obtain the microbial composition of traditional Chinese medicine of Faeces Trogopterori, ten samples were collected from the imitate wildness farmland in Shangluo City, Shaanxi Province. In this study, 16S rRNA gene was used as molecular marker to explore the microbiome and the sequences were analyzed by Usearch analysis platform. The COG and KEGG database is used to predict and analyze the function of the flora. A great number of 285 218 high quality clean reads with a length of 400-450 bp were obtained from 10 samples. Bacterial species detected in these samples covered 8 phyla, 25 families, 75 genera and 120 species. The dominant phylum microbial communities in these samples were Firmicutes (87.68% ± 2.68%) and the Bacteroidetes (7.62% ± 3.74%), all samples showed a high microbial diversity, the predicted functional metagenome was heavily involved in energy metabolism. This study provided that the beneficial bacteria in Faeces Trogopterori may be one of its active ingredients, and no pathogens are detected in the sample.

Analysis of Bacterial Flora Structure of Patients with Cerebral Hemorrhage Due to Hyperactivity of Liver-Yang by 16S rRNA Gene Sequencing Technique / 中国实验方剂学杂志

Objective: To explore the difference of intestinal flora between the patients with acute cerebral hemorrhage due to hyperactivity of liver-Yang and the healthy population. Method: The fecal samples of 9 patients with acute cerebral hemorrhage due to hyperactivity of liver-Yang from the first affiliated hospital of Guangzhou university of traditional Chinese medicine in 2018 were selected as observation group,and 6 stool samples from healthy subjects were selected as the control group.The total bacterial DNA was extracted from the two groups of samples,amplified according to the 16S rRNA V4 region,and paired-end sequencing was performed on the Illumina MiSeq platform.The sequencing results were analyzed by bioinformatics analysis software.The flora composition and structure of the samples from two groups were compared. Result:Venn analysis of operational taxonomic units(OTU) showed significant difference in OTU numbers between the observation group and control group.Partial least squares-discriminant analysis(PLS-DA) showed that there was a significant difference in the composition of intestinal flora between patients with acute cerebral hemorrhage and healthy subjects.On the analysis of species and abundance,at the classification level of phylum,compared with the control group,the ratio of relative abundance values of Firmicutes and Bacteroidetes(F/B) in the observation group was significantly increased,and the relative abundance of Verrucomicrobia was significantly decreased(PPrevotella,Bacteroides,Akkermansia,Blautia and Acidaminococcus(PPBacteroides and Prevotella(B/P) in the observation group was significantly higher than that of the control group;at the classification level of species,there were significant differences between the two groups in P. copri,A. muciniphila,B. ovatus,B. fragilis and Ruminococcus callidus(PPConclusion:Acute cerebral hemorrhage due to hyperactivity of liver-Yang is associated with structural disorder of intestinal flora,which is closely related to the decrease in relative abundance of P. copri and A. muciniphila.

Characterization of rhizospheric microbial flora of Hunyuan Astragali Mongolici Radix by ARISA fingerprinting / 中草药

Objective: To characterize rhizospheric microbial flora of Hunyuan Astragali Mongolici Radix (HAMR) and to provide scientific evidence for understanding quality formation of the herb. Methods: The soil microbial flora were fingerprinted by automated ribosomal intergenic-spacer analysis (ARISA). The raw data were processed and analyzed by GeneMarker and PAST, respectively. Results: Compared with non-rhizospheric soil flora, the rhizospheric flora from 2-and 3-year-old herbs shifted obviously, and the similarities were decreased but diversities increased. Meanwhile, the flora from 5-year-old herbs had no significant similarity difference to non-rhizospheric ones and their sample rare fraction curves were more consistent with each other. When compared to the ones from other production areas, the flora from HAMR had relatively lower core OTUs but had significantly higher abundance of core OTUs shared by all areas. Conclusion: The structure of rhizospheric microbial flora of HAMR is associated with the herb's age and is quite different from thoes from other areas.

The Comparative Analysis of Microorganism Diversity in Two Kinds of Packaged Chilled Beef on Sale / 微生物学通报

This research is for the purpose of comparative analysis of the microbial flora structure in the chilled beef with no packing and cling film, which under the same terms of sale. It was used the V3 area fragment of 16S rDNA to carry on PCR-DGGE, Meanwhile used the 16S rDNA sequence to analysis the microbial flora structure of the two samples, according to the technology of clone .The research discovered that the flora structure displays a biggish difference; there was 6 OTU in the chilled beef with cling film, mainly was that Lactococcus(28%), Lactobacillus (26%), Carnobacterium(18%) and Brochothrix (10%); but there was 18 OTU in the chilled beef with no packing, mainly was that Lactococcus(28%), Brchothrix(18%), Acinetobacter (11%). The result indicates that cling film played a certain inhibitory action regarding the Staphylococcus as well as the cold pole bacteria and such bacterium. And it can provide a certain theory ba-sis for the meat processing in the department of microorganism’s control.