Search

White clover (Trifolium repens L.) belongs to the Fabaceae family legume and is cultivated in China for its medicinal properties and ornamental value. White clover is grown around the world for forage, turf , green manure and soil conservation purposes (Zhang el al. 2016). In October 2021, an investigation of a 1,000 m2 plant nursery in Lanzhou, China (36°06'N, 103°83'E) found that 80% of White clover plants were infected, and powdery mildew covered 95% of the leaf area. The disease had seriously destroyed the forage quality and reduced the ornamental value. Initially, thin, radial, irregular white colonies appeared on leaves and gradually spread to stems. The white colonies then expanded and thickened to cover upper surface of the leaf, and microscopic hyphae appeared on the bottom of the leaf. In severe cases, the infection resulted in dieback of the leaf. A small area of sporulating fungus was stripped off from the leaf surface with tape and mounted in sterile water for microscopic examination (Mukhtar et al. 2017). Conidiophores were cylindrical, consisting of a foot cell followed by three to four short cells, measuring 75 to 160 × 7 to 10 μm. Conidiophores had straight, cylindric foot cells ranging from 25 to 40 µm long. Singly produced conidia were hyaline and ranged in shape from oblong to cylindrical. Conidia lacked distinct fibrotic bodies and measured 30 to 45 × 15 to 25 μm in length. Long, unbranched germ tubes formed from the ends of the conidia and nipple-shaped appressoria developed on epiphytic mycelia. Based on these morphological characteristics, the pathogen was initially identified morphologically as Erysiphe polygoni (Braun and Cook 2012). To validate the identity, the internal transcribed spacer (ITS) region of the pathogen (SY77) rDNA was amplified by PCR and sequenced using the ITS1/ITS4 primers (White et al. 1990). The resulting sequences were registered to GenBank (GenBank Accession No.OM280998). The ITS sequence of the SY77 was 100% (640/640) identical to E. polygoni (LC009892) on Polygonum aviculare in the United Kingdom and 99% (638/640) identical to E. polygoni (MK685172) on Antigonon leptopus in Taiwan. MEGA 7.0 was used to conduct the neighbor-joining phylogenetic analysis using the ITS sequences from GenBank. The data indicated that the strain SY77 and E. polygoni clustered together on the same branch. Pathogenicity tests were conducted by gently pressing the infected leaves onto five healthy potted White clover plants, while five non-inoculated plants were used as controls (Michael et al. 2021). The plants were maintained in a growth chamber (25 ℃, 14 h light, and 10 h dark period, RH80%). After 10 days, the inoculated plants developed powdery mildew symptoms, whereas the control plants remained symptom-free. The fungus on the inoculated plants was re-isolated, re-identified, and confirmed as E. polygoni based on morphological observations and molecular identification. There is no previous report on E. polygoni causing powdery mildew on White clover in China. The powdery mildew caused by E. polygoni on Red clover has been reported in China and Bulgaria, respectively (Yuan el al.1991; Galina el al. 2017). To our knowledge, this is the first report of powdery mildew caused by E. polygoni on White clover in China. References: 1. Zheng, L., et al. 2018. Plant Dis. 102:628. 2. Mukhtar, G., et al. 2017. Plant Dis.101:1, 246. 3. Braun, U., and Cook, R. T. A. 2012. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht. 4. Michael, R. F., et al. 2021.Plant Dis. First look.( doi.org/ 10.1094/PDIS-09-21-2060-PDN). 5. Yuan, Q. H., el al.1991. Pratacult Sci.05:59 (in Chinese). 6. Galina, N., et al, 2017. BIOTECHNOL Anim Husb.33.127.

The prosperity and development of tannery industry have brought about rapid economic growth. However, the tannery landfill without anti-seepage measures in the early stage has generated masses of environmental hazards owing to the lack of awareness in environmental protection. Therefore, it is imperative to pay much attention to the understanding of environmental hazards from tannery waste. In this study, solid samples and groundwater samples were collected from a tannery landfill to study the effect of the characteristic pollutants produced by tanning on chromium distribution with other coexisting substances. The results showed that significant correlations were demonstrated between multiple coexisting substances (total organic carbon, total petroleum hydrocarbons, total nitrogen, Cr, F, Ca, Cu and Pb), indicating the possible same source or they coming from the same tannery production stage. The weights of positive effects and negative effects of coexisting substances on total Cr distribution in the profile decreased in the order: total nitrogen > Cu > Ca > Pb > total organic carbon > F > SO42– > Cd, and Ni > Cl > Hg, respectively. Moreover, the simulation of Visual MINTEQ showed that the cations were mainly bound to Cr as CrO42−, while the anions were bound to Cr3+. This study provided a new perspective on the selection of remediation strategies for Cr-contaminated sites to avoid secondary environmental pollution caused by the release of coexisting heavy metals.

Sludge foaming has been a persistent ailment in worldwide municipal sewage treatment plants (MSTPs). In particular, this problem frequently occurs and lasts throughout the winter and spring season in the sub-plateau MSTPs. Aims to explore the causes of sludge foaming under sub-plateau circumstance, the correlation between the structural and functional changes in bacterial communities and sewage properties was conducted using Illumina high-throughput sequencing technology. The results from 16S rRNA gene sequencing shown that the relative abundances of Actinobacteria (39.5 % ± 4.8 %) and Firmicutes (10.5 % ± 1.0 %) in the foaming sludge were remarkably higher than that in the non-foaming sludge. The abundances of Candidatus Microthrix parvicella (29.8 % ± 6.9 %), Trichococcus (6.5 % ± 1.0 %), and Ornithinibacter (3.5 % ± 0.6 %) were increased after sludge foaming, and which are considered as the dominated foaming-causative bacterial assemblages by the linear discriminant analysis (LDA). Spearman’s correlation analysis and redundancy analysis (RDA) also agreed that lower temperature and dissolved oxygen (DO) levels, higher lipid and protein contents were significantly correlated with sludge foaming. In addition, the predictive functional profiling indicated that the enzymes and their coding genes of the bacterial communities are mainly involved in the fast proliferation and lipid metabolism, and which abundance are highly upregulated during foaming period. These results suggested that the sludge foaming was strongly linked to the Actinobacteria and Firmicutes communities and higher lipid and protein content in the sewage under sub-plateau circumstance. The findings might be important for developing operating strategies to maintain the desired microbial community pattern and improve the performance of MSTPs.

The tannery industry is an integral part of economic development in many developing countries, and the environmental pollution caused by the tannery industry cannot be ignored. In this study, soil and groundwater samples at different depths were collected from an abandoned tannery to investigate the temporal and spatial distribution of characteristic pollutants produced by tanning. The concentrations of Cr, Cl, F and NH4+–N in the soil from the sludge temporary storage area were higher than those from the liming and unhairing workshop, chrome tanning workshop, wastewater outlet, and around wastewater pond. The concentration of Cr(VI) in all sampling sites was below the detection limit. The main species of Cr in the groundwater were Cr(NH3)6Cl2+ and CrO42− based on the simulation of Visual MINTEQ. The saturation index was negative and changed with time indicating that Cr existed in the dissolved phase. The proportion of Cr(VI) to total Cr was negatively correlated with the saturation index in village 1 and village 3. The simulation results from Visual MODFLOW and MT3DMS showed that the migration of Cr, NH4+–N, Cl− and F− mainly occurred in the Quaternary system. The coverage of the pollution plume of pollutants in villages 1 and 3 was as follows: Cr > NH4+−N > Cl− > F−. Two decay rate calculation methods of pollutants with migration time and distance were put forward to provide a basis for the actual investigation of the pollution migration scope and time determination.

Lycopodium japonicumThunb. has attracted great interests due to its rich alkaloids with significant anticancer activity. However, significant chemical differences often exist in a plant species from different geographic origins and affect its quality and bioactivities. Thus, it is urgent to reveal their chemical and biological distinctions at the molecular level. In this context, a comparative chemical analysis of LAs using HPLC-UV-ESI-MS/MS was firstly conducted and resulted in the detection of 46 LAs, 28 of which were identified, and a series of unique LAs markers, such as peaks2,9,10, and11, were further found to be characteristic LAs and selected as markers from four different origins for their quality control. In parallel, the comparative bioactivity assay revealed that the total LAs from Hubei province exhibited much higher inhibitory rate at 65.95% against HepG2 cells than those at 26.72%, 20.26%, and 33.62% for Kenya, Guangxi province, and Zhejiang province in China, respectively. To this end, significant chemical fingerprinting differences and discrepancies in bioactivity of LAs were explored firstly, which could provide valuable information for quality control and further activity studies on LAs from different sources and promote their better pharmaceutical applications in the future as well.

The present study was designed to determine the taxonomic diversity and metabolic activity of the actinomycetes community, including 13 traditional medicinal plants collected in Sichuan province, China, using multiple approaches such as morphological and molecular identification methods, bioactivity assays, and PCR screening for genes involved in antibiotics biosynthesis. 119 endophytic actinomycetes were recovered; 80 representative strains were chosen for 16S rRNA gene partial sequence analyses, with 66 of them being affiliated to genus Streptomyces and the remaining 14 strains being rare actinomycetes. Antimicrobial tests showed that 12 (15%) of the 80 endophytic actinomycetes displayed inhibitory effects against at least one indicator pathogens, which were all assigned to the genus Streptomyces. In addition, 87.5% and 58.8% of the isolates showed anticancer and anti-diabetic activities, respectively. Meanwhile, the anticancer activities of the isolates negatively correlated with their anti-diabetic activities. Based on the results of PCR screening, five genes, PKS-I, PKS-II, NRPS, ANSA, and oxyB, were detected in 55.0%, 58.8%, 90.0%, 18.8% and 8.8% of the 80 actinomycetes, respectively. In conclusion, the PCR screening method employed in the present study was conducive for screening and selection of potential actinomycetes and predicting potential secondary metabolites, which could overcome the limitations of traditional activity screening models.

Community detection is an important methodology for understanding the intrinsic structure and function of a real-world network. In this paper, we propose an effective and efficient algorithm, called Dominant Label Propagation Algorithm (Abbreviated as DLPA), to detect communities in complex networks. The algorithm simulates a special voting process to detect overlapping and non-overlapping community structure in complex networks simultaneously. Our algorithm is very efficient, since its computational complexity is almost linear to the number of edges in the network. Experimental results on both real-world and synthetic networks show that our algorithm also possesses high accuracies on detecting community structure in networks.