The Response of a 16S Ribosomal RNA Gene Fragment Amplified Community to Lead, Zinc, and Copper Pollution in a Shanghai Field Trial.

Industrial and agricultural activities have caused extensive metal contamination of land throughout China and across the globe. The pervasive nature of metal pollution can be harmful to human health and can potentially cause substantial negative impact to the biosphere. To investigate the impact of anthropogenic metal pollution found in high concentrations in industrial, agricultural, and urban environments, 16S ribosomal RNA gene amplicon sequencing was used to track change in the amplified microbial community after metal contamination in a large-scale field experiment in Shanghai. A total of 1,566 operational taxonomic units (OTUs) identified from 448,108 sequences gathered from 20 plots treated as controls or with lead, zinc, copper, or all three metals. Constrained Analysis of Principal Coordinates ordination did not separate control and lead treatment but could separate control/lead, zinc, copper, and three metal treatment. DESeq2 was applied to identify 93 significantly differentially abundant OTUs varying in 211 pairwise instances between the treatments. Differentially abundant OTUs representing genera or species belonging to the phyla Chloroflexi, Cyanobacteria, Firmicutes, Latescibacteria, and Planctomycetes were almost universally reduced in abundance due to zinc, copper, or three metal treatment; with three metal treatment abolishing the detection of some OTUs, such as Leptolyngbya, Desmonostoc muscorum, and Microcoleus steenstrupii. The greatest increases due to metal treatment were observed in Bacteroidetes, Actinobacteria, Chlamydiae, Nitrospirae, and Proteobacteria (α, ß, δ, and γ); the most (relative) abundant being uncharacterized species within the genera Methylobacillus, Solirubrobacter, and Ohtaekwangia. Three metal treatment alone resulted in identification of 22 OTUs (genera or species) which were not detected in control soil, notably including Yonghaparkia alkaliphila, Pedobacter steynii, Pseudolabrys taiwanensis, Methylophilus methylotrophus, Nitrosospira, and Lysobacter mobilis. The capacity to track alterations of an amplified microbial community at high taxonomic resolution using modern bioinformatic approaches, as well as identifying where that resolution is lost for technical or biological reasons, provides an insight into the complexity of the microbial world resisting anthropogenic pollution. While functional assessment of uncharacterized organisms within environmental samples is technically challenging, an important step is observing those organisms able to tolerate extreme stress and to recognize the extent to which important amplifiable community members still require characterization.

Bioremediation of phenol in soil through using a mobile plant-endophyte system.

Plant-endophyte remediation of volatile pollutants in soil is an emerging technology. For more efficient application, plant-endophyte systems were formed through stimulation of transfer of degradative plasmids in plant tissue by co-inoculation of corn, wheat or tomato seedlings with Pseudomonas fluorescens TP13 carrying a self-transmissible degradative plasmid, and P. fluorescens streptomycin-resistant P13 strain. The corn-TP13-P13 (CTP) system had higher degradation activity than other plant-endophyte systems. Transplanting the CTP, from loam to sandy clay loam soil, from greenhouse to field trials, almost completely removed phenol from contaminated soils in 15 d. Intact transplantation of the CTP to contaminated soils was more efficient than co-transplanting of phenol-degrading bacteria and plant in detoxification of phenol. After the experiments the harvested CPT still exhibited remarkable bioremediation activity. The number of degradative plasmid-carrying endophytic bacteria in the CTP system was just slightly more than in the corn seedlings inoculated with TP13 alone, but the former substantially surpassed the latter in phenol-degrading activity, probably due to stimulation of transfer of the degradative plasmids among endophytic bacteria in plant tissues. More degradative plasmid-carrying bacteria colonized bioremediating soil and plant tissues, and higher plasmid transfer frequency and C23O activity of transconjugant were found in soils for the CTP system compared with other treatments. These results showed that the CTP system is a valuable tool to degrade volatile organic pollutants and transfer of degradative plasmids in plant tissues is important for construction of a mobile plant-endophyte system applied in bioremediation of volatile pollutants.

A Review of Flavonoids from Cassia Species and their Biological Activity.

Cassia is a large tropical genus with about 600 species that have been widely used as folk medicines in China and India. This genus has been known to possess various biological activities, e.g. antimicrobial, anti-inflammatory, antioxidant, anti-malarial, anti-mutagenic activity, and anti-fertility etc. Flavonoids, for its broad spectrum of pharmacological activity and low toxicity, have attracted more interest in the development and utilization of natural medicines. The structure and biological activity research of flavonoids extracted from Cassia genus is the first step in the search for new drugs from those plants. This review summarizes the isolation and characterization of flavonoids from various Cassia species, such as Cassia absus, Cassia alata, Cassia fistula, etc. Flavonoids can be extracted from different parts of the plants, such as seed, leaf, stem and pod. Chemical structure research of these flavonoids in extracts has revealed many different types of compounds, which show the complication of the metabolism of Cassia genus. The antidiabetic activities can be found in many Cassia species. The efficiency of extraction method and action mode have been widely investigated. The extract not only can reduce the blood glucose level, but also improve glycogen content. Research show that the methanolic extract is effective in inducing hypoglycemic effects in both type I and II diabetes. Because flavonoids have complex structures, various function points, and unknown pertinence and selectivity for different health conditions, there are still many research areas waiting to be explored, such as to reveal the metabolic pathways of flavonoids in the Cassia genus, and to illustrate the structure-activity relationship between flavonoids and protein. That above-mentioned research will provide the basis for further medicinal development on this genus.

Characterization of the C-terminal sequence of NS5A necessary for the assembly and production of classical swine fever virus infectious particles.

Recent studies show that classical swine fever virus (CSFV) NS5A is an essential replicase component, but it is not known how NS5A participates in viral particle production. In this study, deletion and substitution mutations were introduced into the C-terminus of CSFV NS5A. The efficiency of Core protein release and extracellular and intracellular infectivity levels were assessed and NS5A-Core interaction was investigated. These results suggested that CSFV NS5A was a key factor for the assembly of infectious CSFV particles. The C-terminal sequence from amino acids 478 to 487 and amino acids S481 and T482 were necessary for CSFV assembly and production. The effect of NS5A on CSFV assembly and production might be related to NS5A-Core interaction. T482 was found to be conserved in the C-terminus of NS5A proteins of pestiviruses and hepatitis C virus (HCV), therefore suggesting that it might be important for these virus assembly and production.