This investigation aims to study the characteristics and release properties of lutein-loaded polyvinyl alcohol/sodium alginate (PVA/SA) nanofibers prepared by electrospinning. In order to increase PVA/SA nanofibers’ water-resistant ability for potential biomedical applications, the electrospun PVA/SA nanofibers were cross-linked with a mixture of glutaraldehyde and saturated boric acid solution at room temperature. The nanofibers were characterized using scanning electron microscopy (SEM) and X-ray diffractometer (XRD). Disintegration time and contact angle measurements testified the hydrophilicity change of the nanofibers before and after cross-linking. The lutein release from the nanofibers after cross-linking was measured by an ultraviolet absorption spectrophotometer, which showed sustained release up to 48 h and followed anomalous (non-Fickian) release mechanism as indicated by diffusion exponent value obtained from the Korsmeyer–Peppas equation. The results indicated that the prepared lutein-loaded PVA/SA nanofibers have great potential as a controlled release system.

In this study, we investigated a protocatechuate catabolic gene cluster involved in naphthalene degradation in Rhodococcus ruber OA1. Rhodococcus ruber OA1 was isolated from the pharmaceutical wastewater treatment plant of Xinhua Pharmaceutical Co., Ltd. (Zibo, China). Substrate utilization tests showed that OA1 utilizes naphthalene, phenol, benzoate, salicylate, and protocatechuate as the sole carbon and energy sources for growth. A degradation assay revealed that phthalate is an intermediate in naphthalene degradation and that the protocatechuate pathway plays an important role in naphthalene degradation. To determine the genetic basis and regulation of protocatechuate catabolism in OA1, a fosmid genomic library was constructed and a positive clone carrying the protocatechuate degradation gene cluster was isolated. Sequencing and a bioinformatics analysis identified the complete gene cluster, pcaJIGHBARC, responsible for protocatechuate degradation. Based on this gene cluster, the genes pcaGH (encoding the α and β subunits of protocatechuate 3,4-dioxygenase, 3,4-PCD) were coexpressed and the expressed products showed 3,4-PCD activity. This study illustrates a potential pathway of naphthalene degradation and identifies a protocatechuate pathway in Rhodococcus ruber OA1 for the first time, thus extending our understanding of polycyclic aromatic hydrocarbon degradation and the related aromatic compounds degraded in the process.

An aerobic, non-motile, Gram-stain-negative, pink, convex, coccobacilli-shaped, mesophilic bacterium, designated strain BU-1T, was isolated from an urban soil sample from Zibo city, Shandong province, PR China. The strain grew at 20–37 °C (optimum, 30 °C), pH 5–10 (optimum, pH 7) and growth occurred with 0–2 % (w/v) NaCl (optimally with 0.5 %). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that BU-1T was closely related to members of the genus Roseomonas and had highest 16S rRNA gene sequence similarities with Roseomonas frigidaquae JCM 15073T (97.8 %), Roseomonas tokyonensis JCM 14634T (96.9 %), Roseomonas stagni JCM 15034T (96.5 %), and Roseomonas riguiloci JCM 17520T (95.9 %). BU-1T also formed a subcluster with R. frigidaquae JCM 15073T and R. stagni JCM 15034T in phylogenetic trees based on genomic sequences. The genome size of BU-1T was 5.79 Mb and the DNA G+C content was 71.7 %. ANI, dDDH and AAI values between BU-1T and R. frigidaquae JCM 15073T were 84.0, 27.2 and 86.7 %, respectively. Furthermore, the genome of BU-1T contained 5446 predicted protein coding genes and 4945 (90.8%) of them had classifiable functions. BU-1T contained Q-10 as the main ubiquinone. The predominant fatty acids (>10 %) were summed feature 3, summed feature 8 and C16:0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and five unidentified aminolipids. Combined data from phenotypic, phylogenetic and chemotaxonomic studies indicated that strain BU-1T is a representative of a novel species of the genus Roseomonas . Since strain BU-1T can reduce highly toxic selenite [Se(IV)] to low toxicity elemental selenium [Se(0)], the name Roseomonas selenitidurans sp. nov. is proposed. The type strain is BU-1T (=KACC 21750T =GDMCC 1.1776T).

Sodium benzoate (SB), the sodium salt of benzoic acid, is widely used as a preservative in foods and drinks. The toxicity of SB to the human body attracted people’s attention due to the excessive use of preservatives and the increased consumption of processed and fast foods in modern society. The SB can inhibit the growth of bacteria, fungi, and yeast. However, less is known of the effect of SB on host commensal microbial community compositions and their functions. In this study, we investigated the effect of SB on the growth and development of Drosophila melanogaster larvae and whether SB affects the commensal microbial compositions and functions. We also attempted to clarify the interaction between SB, commensal microbiota and host development by detecting the response of commensal microbiota after the intervention. The results show that SB significantly retarded the development of D. melanogaster larvae, shortened the life span, and changed the commensal microbial community. In addition, SB changed the transcription level of endocrine coding genes such as ERR and DmJHAMT. These results indicate that the slow down in D. melanogaster larvae developmental timing and shortened life span of adult flies caused by SB intake may result from the changes in endocrine hormone levels and commensal microbiota. This study provided experimental data that indicate SB could affect host growth and development of D. melanogaster through altering endocrine hormone levels and commensal microbial composition.

Background: Liao ning virus (LNV) is a member of the genus Seadornavirus, family Reoviridae and has been isolated from kinds of vectors in Asia and Australia. However, there are no systematic studies describe the molecular genetic evolution and migration of LNVs. With the development of bioinformatics, viral genetic data combining the information of virus isolation time and locations could be integrated to infer the virus evolution and spread in nature. Methods: Here, a phylogenetic and phylogeographic analysis using Bayesian Markov chain Monte Carlo simulations was conducted on the LNVs isolated from a variety of vectors during 1990-2014 to identify the evolution and migration patterns of LNVs. Results: The results demonstrated that the LNV could be divided into 3 genotypes, of which genotype 1 mainly composed of LNVs isolated from Australia during 1990 to 2014 and the original LNV strain (LNV-NE97-31) isolated from Liaoning province in northern China in 1997, genotype 2 comprised of the isolates all from Xinjiang province in western China and genotype 3 consisted the isolates from Qinghai and Shanxi province of central China. LNVs emerged about 272 years ago and gradually evolved into three lineages in the order genotype 1, genotype 2 and genotype 3. Following phylogeographic analysis, it shows genotype 1 LNVs transmitted from Australia (113°E-153°E, 10°S-42°S) to Liaoning province (118°E-125°E,38°N-43°N) in Northeast Asian continent then further spread across the central part of China to western China (75°E-95°E,35°N-50°N).