ß-Nicotinamide Mononucleotide Promotes Cell Proliferation and Hair Growth by Reducing Oxidative Stress.

ß-Nicotinamide mononucleotide (NMN) has shown promising effects on intestinal health, and it is extensively applied as an anti-aging and Alzheimer's disease therapeutic, due to its medicinal properties. The effects of NMN on the growth of mouse hair were observed after hair removal. The results indicated that NMN can reverse the state of hair follicle atrophy, hair thinning, and hair sparsity induced by dihydrotestosterone (DHT), compared to that of minoxidil. In addition, the action mechanisms of NMN promoting hair growth in cultured human dermal papilla cells (HDPCs) treated with DHT were investigated in detail. The incubation of HDPCs with DHT led to a decrease in cell viability and the release of inflammatory mediators, including interleukin-6 (IL-6), interleukin-1Beta (IL-1ß) and tumor necrosis factor Alpha (TNF-α). It was found that NMN can significantly lower the release of inflammatory factors induced by DHT in HDPCs. HDPCs cells are protected from oxidative stress damage by NMN, which inhibits the NF-κB p65 inflammatory signaling pathway. Moreover, the levels of androgen receptor (AR), dickkopf-1 (DKK-1), and ß-catenin in the HDPCs were assessed using PCR, indicating that NMN can significantly enhance the expression of VEGF, reduced IL-6 levels and suppress the expression of AR and DKK-1, and notably increase ß-catenin expression in DHT-induced HDPCs.

Diverse Methylmercury (MeHg) Producers and Degraders Inhabit Acid Mine Drainage Sediments, but Few Taxa Correlate with MeHg Accumulation.

Methylmercury (MeHg) is a notorious neurotoxin, and its production and degradation in the environment are mainly driven by microorganisms. A variety of microbial MeHg producers carrying the gene pair hgcAB and degraders carrying the merB gene have been separately reported in recent studies. However, surprisingly little attention has been paid to the simultaneous investigation of the diversities of microbial MeHg producers and degraders in a given habitat, and no studies have been performed to explore to what extent these two contrasting microbial groups correlate with MeHg accumulation in the habitat of interest. Here, we collected 86 acid mine drainage (AMD) sediments from an area spanning approximately 500,000 km2 in southern China and profiled the sediment-borne putative MeHg producers and degraders using genome-resolved metagenomics. 46 metagenome-assembled genomes (MAGs) containing hgcAB and 93 MAGs containing merB were obtained, including those from various taxa without previously known MeHg-metabolizing microorganisms. These diverse MeHg-metabolizing MAGs were formed largely via multiple independent horizontal gene transfer (HGT) events. The putative MeHg producers from Deltaproteobacteria and Firmicutes as well as MeHg degraders from Acidithiobacillia were closely correlated with MeHg accumulation in the sediments. Furthermore, these three taxa, in combination with two abiotic factors, explained over 60% of the variance in MeHg accumulation. Most of the members of these taxa were characterized by their metabolic potential for nitrogen fixation and copper tolerance. Overall, these findings improve our understanding of the ecology of MeHg-metabolizing microorganisms and likely have implications for the development of management strategies for the reduction of MeHg accumulation in the AMD sediments. IMPORTANCE Microorganisms are the main drivers of MeHg production and degradation in the environment. However, little attention has been paid to the simultaneous investigation of the diversities of microbial MeHg producers and degraders in a given habitat. We used genome-resolved metagenomics to reveal the vast phylogenetic and metabolic diversities of putative MeHg producers and degraders in AMD sediments. Our results show that the diversity of MeHg-metabolizing microorganisms (particularly MeHg degraders) in AMD sediments is much higher than was previously recognized. Via multiple linear regression analysis, we identified both microbial and abiotic factors affecting MeHg accumulation in AMD sediments. Despite their great diversity, only a few taxa of MeHg-metabolizing microorganisms were closely correlated with MeHg accumulation. This work underscores the importance of using genome-resolved metagenomics to survey MeHg-metabolizing microorganisms and provides a framework for the illumination of the microbial basis of MeHg accumulation via the characterization of physicochemical properties, MeHg-metabolizing microorganisms, and the correlations between them.

Occurrence and prevalence of seven bee viruses in Apis mellifera and Apis cerana apiaries in China.

Populations of Apis mellifera and Apis cerana in China were surveyed for seven bee viruses: acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Kashmir bee virus (KBV), sacbrood virus (SBV), and Isreal acute paralysis virus (IAPV). No KBV was detected from any samples of the two species. In A. mellifera, DWV was the most prevalent virus, but in A. cerana, SBV was the dominant. Simultaneous multiple infections of viruses were common in both species. This is the first report of detection of IAPV and CBPV in A. cerana.

Patterns and ecological drivers of viral communities in acid mine drainage sediments across Southern China.

Recent advances in environmental genomics have provided unprecedented opportunities for the investigation of viruses in natural settings. Yet, our knowledge of viral biogeographic patterns and the corresponding drivers is still limited. Here, we perform metagenomic deep sequencing on 90 acid mine drainage (AMD) sediments sampled across Southern China and examine the biogeography of viruses in this extreme environment. The results demonstrate that prokaryotic communities dictate viral taxonomic and functional diversity, abundance and structure, whereas other factors especially latitude and mean annual temperature also impact viral populations and functions. In silico predictions highlight lineage-specific virus-host abundance ratios and richness-dependent virus-host interaction structure. Further functional analyses reveal important roles of environmental conditions and horizontal gene transfers in shaping viral auxiliary metabolic genes potentially involved in phosphorus assimilation. Our findings underscore the importance of both abiotic and biotic factors in predicting the taxonomic and functional biogeographic dynamics of viruses in the AMD sediments.

Microbial biogeography of acid mine drainage sediments at a regional scale across southern China.

Investigations of microbial biogeography in extreme environments provide unique opportunities to disentangle the roles of environment and space in microbial community assembly. Here, we reported a comprehensive microbial biogeographic survey of 90 acid mine drainage (AMD) sediment samples from 18 mining sites of various mineral types across southern China. We found that environmental selection was strong in determining the AMD habitat species pool. However, microbial alpha diversity was primarily explained by mining sites rather than environmental factors, and microbial beta diversity correlated more strongly with geographic than environmental distance at both large and small spatial scales. Particularly, the presence/absence of widespread AMD habitat generalists was only correlated with geographic distance and independent of environmental variation. These distance-decay patterns suggested that spatial processes played a more important role in determining microbial compositional variation across space; which could be explained by the reinforced impacts of dispersal limitation in less fluid, spatially structured sediment habitat with diverse pre-existing communities. In summary, our findings suggested that the deterministic assembling and spatial constraints interact to shape microbial biogeography in AMD sediments; and provided implications that spatial processes should be considered when predicting microbial dynamics in response to severe environmental change across large spatial scales.

Globally distributed mining-impacted environments are underexplored hotspots of multidrug resistance genes.

Mining is among the human activities with widest environmental impacts, and mining-impacted environments are characterized by high levels of metals that can co-select for antibiotic resistance genes (ARGs) in microorganisms. However, ARGs in mining-impacted environments are still poorly understood. Here, we conducted a comprehensive study of ARGs in such environments worldwide, taking advantage of 272 metagenomes generated from a global-scale data collection and two national sampling efforts in China. The average total abundance of the ARGs in globally distributed studied mine sites was 1572 times per gigabase, being rivaling that of urban sewage but much higher than that of freshwater sediments. Multidrug resistance genes accounted for 40% of the total ARG abundance, tended to co-occur with multimetal resistance genes, and were highly mobile (e.g. on average 16% occurring on plasmids). Among the 1848 high-quality metagenome-assembled genomes (MAGs), 85% carried at least one multidrug resistance gene plus one multimetal resistance gene. These high-quality ARG-carrying MAGs considerably expanded the phylogenetic diversity of ARG hosts, providing the first representatives of ARG-carrying MAGs for the Archaea domain and three bacterial phyla. Moreover, 54 high-quality ARG-carrying MAGs were identified as potential pathogens. Our findings suggest that mining-impacted environments worldwide are underexplored hotspots of multidrug resistance genes.

Immobilization of ß-CD on a Hyper-Crosslinked Polymer for the Enhanced Removal of Amines from Aqueous Solutions.

In this paper, we adopted a simple and efficient strategy to prepare a ß-cyclodextrin (ß-CD)-modified hyper-crosslinked polymer (CDM-HCP). The structures and physicochemical properties of the as-synthesized polymer were also evaluated. It was applied to the removal of anilines from aqueous solutions. The introduction of ß-CD into the hyper-crosslinked polymer significantly enhanced adsorption properties for the removal of various amines. The adsorption kinetics agreed with the pseudo-second-order mode very well. The adsorption isotherm data of p-methylaniline (p-MA) and p-aminobenzoic acid (p-ABC) were in agreement with the Langmuir isotherm, whereas aniline and p-chloroaniline (p-CA) were fitted best with the Freundlich model. The maximum adsorption capacities (qmax) determined by adsorption isotherms were 148.97 mg/g for aniline, 198.45 mg/g for p-MA, 293.71 mg/g for p-CA, and 622.91 mg/g for p-ABC, respectively. It had higher adsorption capacities than those of some commercial polymeric resins, such as XAD-4, PA66, and AB-8. The interaction mechanism was investigated by FTIR, XPS, and the ONIOM2 method. A CDM-HCP can be regenerated efficiently and used repeatedly, indicating its potential technological applications in removing organic pollutants from actual industrial effluents.

Improved welan gum production by Alcaligenes sp. ATCC31555 from pretreated cane molasses.

Welan gum production by Alcaligenes sp. ATCC31555 from cane molasses was studied in batch fermentation to reduce production costs and enhance gum production. The pretreatment of cane molasses, agitation speed and the addition of supplements were investigated to optimize the process. Sulfuric acid hydrolysis was found to be the optimal pretreatment, resulting in a maximum gum concentration of 33.5 g/L, which is 50.0% higher than those obtained from the molasses' mother liquor. Agitation at 600 rpm at 30°C and addition of 10% n-dodecane following fermentation for 36 h increased the maximum gum production up to 41.0 ± 1.41 g/L, which is 49.1% higher than the greatest welan gum concentration in the literature so far. The welan gum product showed an acceptable molecular weight, similar rheological properties and better thermal stability to that obtained from glucose. These results indicate that cane molasses may be a suitable and inexpensive substrate for cost-effective industrial-scale welan gum production.

Draft Genome Sequence of an Anaerobic, Thermophilic Bacterium, Thermoanaerobacterium aotearoense SCUT27, Isolated from a Hot Spring in China.

Thermoanaerobacterium aotearoense SCUT27, isolated from a hot spring in China, is a strictly anaerobic, thermophilic bacterium capable of degrading xylan and converting both pentose and hexose to ethanol with high yields. Here, we report the draft genome sequence of SCUT27, which reveals insights into the mechanisms of carbon source coutilization and xylan degradation in this thermophilic microorganism.

Enhanced butanol production by coculture of Clostridium beijerinckii and Clostridium tyrobutyricum.

Cocultures of Clostridium beijerinckii and Clostridium tyrobutyricum in free-cell and immobilized-cell fermentation modes were investigated as a means of enhancing butanol production. The immobilized fermentation was performed in a fibrous-bed bioreactor (FBB). The results demonstrated that two-strain coculture significantly enhanced butanol production, yield and volumetric productivity compared with those in pure culture with or without butyric acid. Further, continuous immobilized-cell cocultures in two FBBs using glucose, cassava starch, or cane molasses were conducted at a dilution rate of 0.144 h(-1). The butanol production (6.66 g/L), yield (0.18 g/g), and productivity (0.96 g/L/h) were obtained with cassava starch as the substrate. Meanwhile, the acetone-butanol-ethanol (ABE) yield (0.36 g/g) was the highest among all processes investigated, suggesting that this continuous coculture mode may be suitable for industrial ABE production with no need for repeated sterilization and inoculation.