Safe utilization of bioresources in gentamicin mycelial residues by thermal treatment: Antibiotic degradation, resistance gene inactivation and available nutrients promotion.

Gentamicin mycelium residues (GMRs) abundant in organic substances were generated during the production of gentamicin. Inappropriate handling techniques not only waste valuable resources, they could also result in residual gentamicin into the natural environment, leading to the generation of antibiotic resistance genes (ARGs), which would cause a significant threat to ecological system and human health. In the present work, the effects of thermal treatment on the removal of residual gentamicin in GMRs, as well as the changes of associated ARGs abundance, antimicrobial activity and bioresources properties were investigated. The results indicated that the hazards of GMRs was significantly reduced through thermal treatment. The degradation rate of residual gentamicin in GMRs reached 100 %, the total abundance of gentamicin resistance genes declined from 8.20 to 1.14 × 10-5 and the antibacterial activity of the decomposition products of GMRs on Vibrio fischeri was markedly reduced at 200 °C for 120 min. Additionally, the thermal treatment remarkably influenced the bioresource properties of GMRs-decomposition products. The release of soluble organic matters including soluble carbohydrates and soluble proteins have been enhanced in GMRs, while excessively high temperatures could lead to a reduction of nutrient substances. Generally, thermal treatment technology was a promising strategy for synergistic reducing hazards and utilizing bioresources of GMRs.

Haplotype-resolved genome of diploid ginger (Zingiber officinale) and its unique gingerol biosynthetic pathway.

Ginger (Zingiber officinale), the type species of Zingiberaceae, is one of the most widespread medicinal plants and spices. Here, we report a high-quality, chromosome-scale reference genome of ginger 'Zhugen', a traditionally cultivated ginger in Southwest China used as a fresh vegetable, assembled from PacBio long reads, Illumina short reads, and high-throughput chromosome conformation capture (Hi-C) reads. The ginger genome was phased into two haplotypes, haplotype 1 (1.53 Gb with a contig N50 of 4.68 M) and haplotype 0 (1.51 Gb with a contig N50 of 5.28 M). Homologous ginger chromosomes maintained excellent gene pair collinearity. In 17,226 pairs of allelic genes, 11.9% exhibited differential expression between alleles. Based on the results of ginger genome sequencing, transcriptome analysis, and metabolomic analysis, we proposed a backbone biosynthetic pathway of gingerol analogs, which consists of 12 enzymatic gene families, PAL, C4H, 4CL, CST, C3'H, C3OMT, CCOMT, CSE, PKS, AOR, DHN, and DHT. These analyses also identified the likely transcription factor networks that regulate the synthesis of gingerol analogs. Overall, this study serves as an excellent resource for further research on ginger biology and breeding, lays a foundation for a better understanding of ginger evolution, and presents an intact biosynthetic pathway for species-specific gingerol biosynthesis.

Musk Ketone Induces Neural Stem Cell Proliferation and Differentiation in Cerebral Ischemia via Activation of the PI3K/Akt Signaling Pathway.

Traditional Chinese medicine has been reported to influence the proliferation and differentiation of neural stem cells (NSCs) that may be protective against nervous system diseases. Recent evidence indicates the importance of musk ketone in nerve recovery and preventing secondary damage after cerebral ischemic injury. A middle cerebral artery occlusion (MCAO) rat model was established by a transient filament model, and rats were treated with musk ketone (0.9 or 1.8 µM). Next, an in vitro oxygen-glucose deprivation (OGD) cell model was established to study the effect of musk ketone on the proliferation and differentiation of NSCs. To determine the potential mechanisms of musk ketone involved in activities of NSCs, the effect of musk ketone on the PI3K/Akt signaling pathway activation was assessed. Furthermore, NSCs were treated with musk ketone in the presence of PI3K/Akt inhibitor Akti-1/2 to examine their roles on NSC proliferation and differentiation. Musk ketone reduced cerebral ischemic injury in a dose-dependent manner in rats. In addition, NSCs treated with musk ketone showed enhanced proliferation and differentiation along with increased PI3K/Akt signaling pathway activation. The effects of muck ketone were reversed by Akti-1/2. Altogether, musk ketone promoted NSC proliferation and differentiation and protected against cerebral ischemia by activating the PI3K/Akt signaling pathway, highlighting the potential of musk ketone as a physiologically validated approach for the treatment of cerebral ischemia.

Draft genome sequence of the Tibetan medicinal herb Rhodiola crenulata.

Rhodiola crenulata, a well-known medicinal Tibetan herb, is mainly grown in high-altitude regions of the Tibet, Yunnan, and Sichuan provinces in China. In the past few years, increasing numbers of studies have been published on the potential pharmacological activities of R. crenulata, strengthening our understanding into its putitive active ingredient composition, pharmacological activity, and mechanism of action. These findings also provide strong evidence supporting the important medicinal and economical value of R. crenulata. Consequently, some Rhodiola species are becoming endangered because of overexploitation and environmental destruction. However, little is known about the genetic and genomic information of any Rhodiola species. Here we report the first draft assembly ofthe R. crenulata genome, which was 344.5 Mb (25.7 Mb Ns), accounting for 82% of the estimated genome size, with a scaffold N50 length of 144.7 kb and a contig N50 length of 25.4 kb. The R. crenulata genome is not only highly heterozygous but also highly repetitive, with ratios of 1.12% and 66.15%, respectively, based on the k-mer analysis. Furthermore, 226.6 Mb of transposable elements were detected, of which 77.03% were long terminal repeats. In total, 31 517 protein-coding genes were identified, capturing 86.72% of expected plant genes in BUSCO. Additionally, 79.73% of protein-coding genes were functionally annotated. R. crenulata is an important medicinal plant and also a potentially interesting model species for studying the adaptability of Rhodiola species to extreme environments. The genomic sequences of R. crenulata will be useful for understanding the evolutionary mechanism of the stress resistance gene and the biosynthesis pathways of the different medicinal ingredients, for example, salidroside in R. crenulata.

Transcriptome analysis of leaves, roots and flowers of Panax notoginseng identifies genes involved in ginsenoside and alkaloid biosynthesis.

BACKGROUND: Panax notoginseng (Burk.) F.H. Chen is one of the most highly valued medicinal plants in the world. The major bioactive molecules are triterpene saponins, which are also known as ginsenosides. However, its large genome size has hindered the assembly of a draft genome by whole genome sequencing. Hence, genomic and transcriptomic details about P. notoginseng, especially its biosynthetic pathways and gene expression in different parts of the plant, have remained largely unknown until now. RESULTS: In this study, RNA sequencing of three different P. notoginseng tissues was performed using next generation DNA sequencing. After assembling the high quality sequencing reads into 107,340 unigenes, biochemical pathways were predicted and 9,908 unigenes were assigned to 135 KEGG pathways. Among them, 270 unigenes were identified to be involved in triterpene saponin biosynthesis. In addition, 350 and 342 unigenes were predicted to encode cytochrome P450s and glycosyltransferases, respectively, based on the annotation results, some of which encode enzymes responsible for the conversion of the triterpene saponin backbone into different ginsenosides. In particular, one unigene predominantly expressed in the root was annotated as CYP716A53v2, which probably participates in the formation of protopanaxatriol from protopanaxadiol in P. notoginseng. The differential expression of this gene was further confirmed by real-time PCR. CONCLUSIONS: We have established a global transcriptome dataset for P. notoginseng and provided additional genetic information for further genome-wide research and analyses. Candidate genes involved in ginsenoside biosynthesis, including putative cytochrome P450s and glycosyltransferases were obtained. The transcriptomes in different plant tissues also provide invaluable resources for future study of the differences in physiological processes and secondary metabolites in different parts of P. notoginseng.

Investigating the mechanisms of biochar's removal of lead from solution.

The objective of this study was to investigate the relationship between Pb(2+) adsorption and physicochemical properties of biochars produced at different pyrolytic temperatures. Ten biochars were prepared from peanut shell (PS) and Chinese medicine material residue (MR) at 300-600°C. Adsorption kinetics and isotherms were determined, and the untreated and Pb(2+)-loaded biochars were analyzed by FTIR, SEM-EDX and XRD. Functional groups complexation, Pb(2+)-π interaction and precipitation with minerals jointly contributed to Pb(2+) adsorption on these biochars. New mineral precipitates (e.g., Pb2(SO4)O and Pb4(CO3)2(SO4)(OH)2) formed during Pb(2+) sorption. For high-temperature biochars (⩾500°C), Pb(2+) sorption via complexation reduced, but the contribution of Pb(2+)-π interaction was enhanced. Dramatic reduction of Pb(2+) sorption on demineralized biochars indicated the dominant role of minerals. These results are useful for screening effective biochars as engineered sorbents to remove or immobilize Pb(2+) in polluted water and soil.

The complex jujube genome provides insights into fruit tree biology.

The jujube (Ziziphus jujuba Mill.), a member of family Rhamnaceae, is a major dry fruit and a traditional herbal medicine for more than one billion people. Here we present a high-quality sequence for the complex jujube genome, the first genome sequence of Rhamnaceae, using an integrated strategy. The final assembly spans 437.65 Mb (98.6% of the estimated) with 321.45 Mb anchored to the 12 pseudo-chromosomes and contains 32,808 genes. The jujube genome has undergone frequent inter-chromosome fusions and segmental duplications, but no recent whole-genome duplication. Further analyses of the jujube-specific genes and transcriptome data from 15 tissues reveal the molecular mechanisms underlying some specific properties of the jujube. Its high vitamin C content can be attributed to a unique high level expression of genes involved in both biosynthesis and regeneration. Our study provides insights into jujube-specific biology and valuable genomic resources for the improvement of Rhamnaceae plants and other fruit trees.