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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.

Root border cells (RBCs) originate from the root tip epidermis and surround the root apices. In this study, we evaluated the developmental characteristics and the roles of RBCs in protection of root apices of cucumber and figleaf gourd seedlings from CA toxicity. The formation of RBCs and the emergence of the root tip occurred almost simultaneously in root apices of cucumber and figleaf gourd seedlings. CA ranging from 0 to 0.25 mol L−1 inhibited root elongation and decreased root cell viability in the root tip, moreover the inhibitory effects of CA were more significant in the CA-sensitive cucumber than in the CA-tolerant figleaf gourd. Removal of RBCs from root tips led to more severe CA induced inhibition of root elongation and decline in root cell viability. Increasing CA levels and treatment time decreased the relative viability of attached and detached RBCs. CA also induced a thicker mucilage layer surrounding attached RBCs of both species. Additionally, a significantly higher relative cell viability of attached RBCs and thicker mucilage layers were observed in figleaf gourd. These results suggest that RBCs play an important role in protecting root tips from CA toxicity.

Rapamycin produced by Streptomyces hygroscopicus displays immunosuppressive, antifungal, anti-tumor, anti-inflammatory and neuro-regenerative properties. To enhance production of rapamycin, aveR, a stimulator in Streptomyces avermitilis, was integrated into the chromosome of S. hygroscopicus TYQ0915. This resulted in a 274.9% increase of rapamycin production in an exconjugant S. hygroscopicus AVH1124. Introduction of aveR acts pleiotropically by affecting growth and sporulation of S. hygroscopicus AVH1124, although aveR is verified to be a pathway-specific regulator in S. avermitilis. This study proved that introduction of a homologous regulatory gene from the same protein family enhanced rapamycin production.

Three new phytane-type diterpene-γ-lactone shaliuin I (2), shaliuin II (3) and shaliuin III (4) were isolated along with thirteen known compounds from twigs of Salix cheilophila omitted (Chinese name "Shaliu", Salicaceae). The structures of three new compounds have been established on the basis of spectroscopic methods and 2D NMR techniques.

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.

Nocardia, Rhodococcus and Streptomyces, all members of the actinomycetes family, are Gram-positive eubacteria with high G+C content and able to form mycelium. We report here a newly identified plasmid pXT107 of Nocardia sp. 107, one of the smallest circular plasmids found in Nocardia. The complete nucleotide sequence of pXT107 consisted of 4335 bp with 65% G+C content, and encoded one replication extragenic palindromic (Rep) and six hypothetical proteins. The Rep, double-strand origin and single-strand origin of pXT107 resembled those of typical rolling-circle-replication plasmids, such as pNI100 of Nocardia, pRE8424 of Rhodococcus and pIJ101 of Streptomyces. The Escherichia coli-Nocardia shuttle plasmid pHAQ22, containing the rep gene of pXT107, is able to propagate in Nocardia but not in Streptomyces.