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Background: Amylase used in the market is mostly medium-temperature enzyme or high-temperature enzyme and has poor enzyme activity under low-temperature environment. Acid α-amylase can be used to develop digestion additives in the pharmaceutical and healthcare industries. The amino acid sequence and structural differences among α-amylases obtained from various organisms are high enough to confer interesting biochemical diversity to the enzymes. However, low- temperature (0-50°C) amylase, with an optimum temperature and heat sensitivity, has a greater potential value than medium (50-80°C) and high (80-110°C) temperature amylases. Methodology: The gene amy48 from encoding extracellular α-amylase in Bacillus subtilis YX48 was successfully cloned into the pET30a (+) vector and expressed in Escherichia coli BL21 (DE3) for biochemical characterization. Results and Conclusion: The molecular weight of α-amylase was 75 kDa. The activity of α-amylase was not affected by Ca2+, and Amy48 had the best activity at pH 5.0 and 37°C. AMY48 has high stability over a narrow pH and temperature range (5.0-8.0 and 30-45°C). Amylase activity was strongly inhibited by Zn2+, Mn2+, Cu2+, and Fe2+ ions, but Na+, K+, and Co2+ ions stimulate its activity slightly. The purified enzyme showed gradually reduced activity in the presence of detergents. However, it was remarkably stable against EDTA and urea.

Objectives Glioblastoma multiforme (GBM) is a common and fatal brain tumour in the central nervous system with a poor survival rate and a median survival time of 15 months only. The standard treatment is aggressive surgical resection followed by radiotherapy and chemotherapy. However, effective drugs available in chemotherapy are limited. This study was designed to evaluate, for the first time, the potential therapeutic effect of Cissus quadrangularis (CQ) in human glioblastoma cells and to investigate its possible mechanisms of action. Methods In this study, we examined the anticancer activity of CQ in human glioblastoma U87 MG cells by cell viability assay, cell migration assay, immunofluorescence staining and Western blot. Results Our results demonstrated that CQ treatment induced U87 cytotoxicity, cell cycle arrest and cell death. The cytotoxicity of CQ mediates ER stress, autophagy and mitochondrial apoptosis by suppressing pro-survival signalling pathways (extracellular signal-regulated kinase and signal transducer and activator of transcription 3 pathways). Conclusions The findings of this study imply that CQ is a promising anti-cancer candidate for the treatment of GBM.

Genome of Pseudomonas fluorescens W-6, a cold-adapted bacterium isolated from Napahai plateau wetland was sequenced and analyzed. W-6 genome length was 6,109,123 bp with G + C content 59.79%. Gene prediction yielded 5,464 protein coding sequences, 70 tRNAs, 24 gene islands and 2 CRISPR sequences. The isolate was found to contain evidence of horizontal gene transfer events during its evolution. Two prophages were predicted and indicated that W-6 was a lysogen. The cold adaptation of W-6 strain showed psychrophilic rather than psychrotrophic characteristics. Cold-adapted bacterium W-6 had glycogen and trehalose metabolism pathways associated with carbohydrate active enzyme, and it utilized they as sources of energy to adapt and survive in low temperature environment. In addition, the cold-adapted mechanisms of W-6 included membrane fluidity by changing unsaturated fatty acid profile, the two-component regulatory systems, anti-sense transcription, the role played by rpsU genes in the translation process etc. The genome-wide analysis of W-6 provides us with a deeper understanding of the cold-adapted environment. The adaptive mechanism of psychrophilic W-6 strain for survival in cold environment was elucidated, which provides a strong basis for further study on host-phage coevolution.

Hybrid histidine kinases (HHKs) are major sensor proteins for fungi that contribute to stress tolerance. In the present work, we investigated the roles and mechanisms of the HHK HisK2301 in cold-adapted Rhodosporidium kratochvilovae strain YM25235. The HisK2301 deletion strain was constructed by homologous recombination method and arranged for multiple stress tests. We analysed the content of carotenoid using UV-Vis and HPLC. Relative transcript levels of genes phytoene desaturase (RKCrtI) and phytoene synthase and lycopene cyclase (RKCrtYB) were analysed by RT-qPCR. Intracellular reactive oxygen species (ROS) generation was measured using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). Our results clearly indicated that YM25235 produces γ-carotene, torulene, β-carotene and torularhodin, with the latter two components strongly related to adapt to cold. HisK2301 is crucial for YM25235 adaptation to different types of stress such as cold, salt, osmotic and oxidative stress. Growth at low temperature clearly induced oxidative stress in YM25235, as more ROS accumulated at cold. During cold stress, HisK2301 is suggested to sense cold-induced ROS signals and then promote carotenoid production partially by RKCrtI and RKCrtYB to scavenge excessive ROS production. Such an inducible protective system may confer YM25235 fast response and better adaptation to cold stress. To conclude, our findings give the first insight into the effect of HisK2301 on carotenoid biosynthesis and cold-induced oxidative stress in fungi under low temperature and suggest the potential use of the cold-adapted HHK HisK2301 in industrial production of carotenoid.

As a waste resource, waste cooking oil (WCO) has not been widely used. Based on the characteristics of WCO cracking, this study proposed to replace fossil-based reductant with WCO for copper slag cleaning, to solve the problem of carbon neutralization in this process. Copper slag cleaning experiments were carried out in a lab-scale electric furnace. The matte separated behavior from slag and the distribution of matte in slag were studied. The results showed that the Fe3O4 content decreases from 12.9 to 3.5 wt.% by injecting 2.2 mL of WCO into 300 g copper slag at 1250?C. The distribution of copper content in slag is gradient along the vertical direction. In the reduction stage, the excessive Fe3O4 is reduced and the fluidity of slag is improved. When the precipitation time is above 60 minutes, the copper content in the middle and upper slag is reduced to 0.57 wt.%, which realizes the copper slag cleaning by using WCO.

Intracellular Fe3+ amount is one of the critical determinants of human health. The development of simple and effective probes for the quantitative detection of Fe3+in vivo is of great significance for the early diagnosis of disease or disorder associated with iron deficiency or overload. In this study, remarkable carbon dots, which can serve as a biosensor for efficient intracellular Fe3+ detection, were synthesized by hydrothermal carbonization of Fusobacterium nucleatum, an anaerobic bacterium. The achieved F. nucleatum-carbon dots (Fn-CDs) possessed the features of strong fluorescence, high stability and excellent biocompatibility. The obtained Fn-CDs could easily internalize into both plant cells and human cells with excellent ability for cell tracking and biomedical labeling. The fluorescence of Fn-CDs could still remain for another 24 hours after penetrating into cells. Furthermore, the fluorescent Fn-CDs were very sensitive to the presence of Fe3+ ions even in cells, exhibiting great promising applications in in vivo detection of Fe3+ ions. In addition, the Fn-CDs posed no harm to the mice, being circulated and excreted within a short time, making the Fn-CDs an excellent candidate for bioimaging and biosensing in vivo.

Among antibacterial nanomaterials, carbon dots (CDs) have attracted much attention because of their unique physical and chemical properties and good biosafety. In this study, kanamycin sulfate (Kan), a broad-spectrum antibiotic, was used to synthesize novel carbon dots (CDs-Kan) by a one-step hydrothermal method. CDs-Kan showed good inhibitory effects on Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Further, scanning electron microscopy revealed that treatment with CDs-Kan and Kan resulted in the same phenomena. In particular, the morphologies of S. aureus cells treated with CDs-Kan and Kan became smaller and irregular, whereas the surfaces of E. coli cells protruded and formed vesicles. These results indicated that CDs-Kan was shown to retain the good antibacterial activity of Kan as well as its main bactericidal functional groups, namely, the amino sugar and amino cyclic alcohol, We refer to this phenomenon as the “preservation property”. We also found that CDs-Kan has good biocompatibility and nontoxic properties. Moreover, CDs-Kan was successfully applied to the biological imaging of fungi and plant cells. In addition, CDs-Kan could be used as a fluorescent probe for the quick, sensitive, and selective detection of Cr6+. Therefore, CDs-Kan not only retained the good bacteriostatic properties of Kan but also expanded its application in bioimaging and biosensors.

Carbon dots (CDs) have excellent application prospects in various fields such as fluorescent dyes, but expanding their application, especially in bioimaging and the detection of organic pollutants, is still a major research objective. In this study, fluorescent CDs were successfully synthesized via the hydrothermal method using Serratia marcescens KMR-3. The platform based on CDs-KMR3 exhibited excellent stability, good biocompatibility, and low biotoxicity, and can be effectively applied to the imaging of bacteria, fungi, plant cells, protozoa and mammalian cells, and can specifically stain the membranes of all tested cells. In this study, for the first time, bacteria-derived CDs were used to image the representative species of organisms ranging from lower-order to higher-order organisms, thereby proving the feasibility of the application of CDs in the fluorescence imaging of Paramecium caudatum. Additionally, CDs-KMR3 can rapidly diffuse into all the parts of the leaf through diffusion into the veins and intercellular interstitium in response to the induction of transpiration. Moreover, the data illustrate that CDs-KMR3 are likely to enter the digestive tracts of microworms by ingestion through the oral cavity and pharynx, and spread to the pseudocoelom and somatic cells, and finally to be excreted from microworms through the anus. Furthermore, this platform can be utilized as fluorescent probes for the rapid and highly selective detection of p-nitrophenol (p-NP). Moreover, this study contributed to the increased application of bacteria-derived CDs in bioimaging and detection of p-NP.

Carbon dots (CDs) and photoluminescent carbon dots (Pn-CDs) are promising nanomaterials due to their bioimaging applications and have attracted considerable attention because of their excellent stability, good biocompatibility, and low biotoxicity. Here, the Pn-CDs and highly fluorescent nitrogen-doped CDs (Pn N-CDs) derived from Panax notoginseng were successfully synthesized by a simple hydrothermal method. Pn N-CDs exhibit optical properties and stability superior to those of Pn-CDs and can be better used as fluorescent dyes and probes in biological imaging. The obtained Pn N-CDs can be effectively applied to the imaging of bacteria, fungi, plant cells, and protozoa. In addition, Pn N-CDs can perform specific staining on the membranes of all tested cells. The in vivo imaging of mice revealed that Pn N-CDs exhibit nontoxicity and good biocompatibility and biodistribution. Furthermore, Pn N-CDs can be utilized as fluorescent probes for the rapid and highly selective detection of Cr6+. Hence, a simple, cost-effective, scalable, and green synthetic approach based on traditional Chinese medicine-derived CDs can be used to develop biolabeling, membrane targeting, and optical sensing probes.

In this study, for the first time, Porphyromonas gingivalis, an anaerobic bacterium, was selected to synthesize carbon dots. The achieved P. gingivalis-carbon dots (Pg-CDs) exhibited strong fluorescence and high stability with capability for dual function as Fe3+ sensor and intracellular imaging agent. The detection limit for Fe3+ was as low as 1.85 µm. On the other hand, the prepared Pg-CDs were an excellent candidate for biosensor with high biocompatibility.

Although bacteriophages are more numerous and have smaller genomes than their bacterial hosts, relatively few have their genomes sequenced. Here, we isolated the Pseudomonas fluorescens bacteriophage from Napahai plateau wetland and performed de novo genome sequencing. Based on the previous biological characteristics and bioinformatics analysis, it was determined that VW-6B was a linear double-stranded DNA (dsDNA) phage with 35,306 bp, with 56.76% G+C content and 197 bp tandem repeats. The VW-6B genome contained 46 open-reading frames (ORFs), and no tRNA genes were found. Based on phage genome structure, sequence comparison, and collinear analysis, VW-6B should be classified into the family Siphoviridae and be considered as a member of a new species in the Mu-like phage. The newly isolated bacteriophage can specifically infect P. fluorescens, which further enriches the diversity of known bacteriophages and provides a basis for the subsequent research and application of bacteriophages.

Enterococcus faecalis is a common pathogen causing refractory periapical periodontitis and secondary intraradicular infections. In this study, E. faecalis YN771 isolated from a re-treated root canal at a stomatology department was used as the host bacterium and was co-cultured with wastewater from the same department and patient samples to isolate a phage that lyses E. faecalis. We studied the biological and genomic characteristics of this phage. Transmission electron microscopy showed that this phage’s head is icosahedral in structure, with a head diameter of around 98.4 nm, and a contractile tail of around 228.5 nm in length and a diameter of 17.3 nm. The phage was identified as a member of the Myoviridae family and named PEf771. It is sensitive to proteinase K but resistant to chloroform and Triton X-100. Its lytic cycle is 45 min, burst size is 78, optimal multiplicity of infection is 0.1, lysis spectrum is narrow, and host strain specificity is strong. Its optimal growth temperature is 37 °C, most suitable pH is 6.0, and is sensitive to ultraviolet radiation. Whole-genome sequencing of PEf771 indicated it has a genome size of 151 052 bp, with a GC content of 36.97%, and encodes 197 proteins plus 26 tRNAs. PEf771 is most closely related to E. faecalis phage EFDG1. Phage PEf771 has strong host specificity and lytic ability, so it is important to further characterize this phage and its interaction with E. faecalis.

Phages are considered the most abundant and diverse biological entities on Earth. Although many phages have been isolated, most of this diversity remains completely unexplored. Recent advances in genome sequencing, however, have provided unprecedented glimpses into the virosphere. The lytic cold-active Siphoviridae bacteriophage VW6S, infecting the host Pseudomonas fluorescens W-6, was isolated from the Napahai plateau wetland in China. The newly sequenced phage VW6S contained double-stranded DNA with a genome size of 37,917 bp, an overall GC content of 56.90% and 52 open reading frames (ORFs). The genome was organized into several modules containing genes for packaging, structural proteins, replication/transcription, and cell lysis. The sequence contained 16 transcription terminators, no tRNAs. The lysis cassette of VW6S consisted of 4 proteins (holin protein, lysin protein and 2 putative spanins). This is the first report on cold-active SiphoviridaePseudomonas fluorescens bacteriophage genome sequencing.

Prodigiosin (2-methyl-3-pentyl-6-methoxyprodiginine), a red-colored microbial pigment, is produced in large quantities by Serratia marcescens KMR-3. This bacterium can grow in a medium with a Cd

Heavy metal contamination is a global issue, with cadmium (Cd

Hexavalent chromium (Cr[Formula: see text]), a heavy metal ion, is widely used in a variety of industries, but it is an environmental pollutant and a recognized human carcinogen. Highly selective quantitative detection of Cr[Formula: see text] is important for environmental pollution monitoring and early disease prevention in humans. In this study, nitrogen-containing carbon quantum dots (N-CQDs) were synthesized by hydrothermal carbonization of Pseudomonas aeruginosa and were found to be efficient detectors of Cr[Formula: see text], with a detection limit (LOD) of 0.23 nmol L[Formula: see text](nM). N-CQDs were detectable in plant leaves and onion cells and successfully stained cell membranes and nuclei. Multi-colored images revealed that in Caenorhabditis elegans, N-CQDs entered the digestive tract through ingestion, spared rapidly throughout the body, and were excreted though the anus within 40 min. Synthesis of fluorescent N-CQDs can be exploited to increase the use and a range of applications of bacterial resources. The study methods and results also provide theoretical guidance for future research into the development of bacterial resources.

Due to the special geographical location and the complex ecosystem types, plateau wetlands play important ecological roles in water supply, greenhouse gas regulation and biodiversity preservation. Napahai plateau wetland is a special wetland type with low latitude and high altitude, and its microbial diversity was rarely studied. The diversity of microbial communities in the Napahai plateau wetland was analyzed using metagenomics method. Among the microbes detected, 184 phyla, 3 262 genera and 24 260 species belong to the bacterial domain, 13 phyla and 32 genera belong to the archaeal domain, and 13 phyla and 47 genera belong to the fungal domain. Significant differences in species diversity between soil and water were observed. Acidobacteria, Proteobacteria and Actinobacteria were dominant phyla in soil, while Proteobacteria and Bacteroides were dominant phyla in water. Since the carbon and nitrogen metabolism genes were abundant, the pathways of carbon fixation and nitrogen metabolism were analyzed. Calvin cycle, reductive tricarboxylic acid cycle and 3-hydroxypropionic acid cycle were the main carbon fixation pathways, while Proteobacteria, Chloroflexi, and Crenarchaeota were the main carbon-fixing bacteria group. As for the nitrogen cycle, nitrogen fixation and dissimilatory nitrate reduction were dominant in water, while nitrification and denitrification were dominant in soil. Proteobacteria, Nitrospirae, Verrucomicrobia, Actinobacteria, Thaumarchaeota and Euryarchaeota contributed to the nitrogen cycle. The study on microbial diversity of Napahai plateau wetlands provides new knowledge for the comprehensive management and protection of wetland environment in China.

Large-scale intensive cultivation has made continuous cropping soil sickness more serious for

A phage PEf771 that specifically infects and lyses pathogenic Enterococcus faecalis YN771 in patients with refractory periapical periodontitis was used to investigate resistance against E. faecalis infection in vitro and in vivo. PEf771 completely lysed YN771 within 3 h, with a multiplicity of infection of 1. Compared with ten routinely used clinical antibiotics, PEf771 demonstrated the highest bacteriostatic effect within 72 h. The antibacterial effect of PEf771 on extracted teeth within 72 h was better than that of conventional root canal disinfectants such as camphorated phenol, formaldehyde cresol solution, and Ca(OH)

In response to the restriction of nutrients and predation by natural enemies, bacteria have evolved complex coping strategies to ensure the reproduction and survival of individual species. Quorum sensing (QS) is involved in the bacterial response to phage predation and regulation of cellular metabolism. However, to date, no clear evidence exists regarding the involvement of autoinducer-2 (AI-2)-mediated QS systems in Escherichia coli in response to the challenges of nutrient restriction and phage infection. In this study, the role of the AI-2-mediated QS system in resisting T4 phage infection and regulating cell mechanisms in E. coli was revealed for the first time. This effect of the AI-2-mediated QS was achieved by simultaneously downregulating the T4 absorption site and carbon and glucose metabolism. Additionally, we found that lsrB, a metabolic brake, participates in AI-2-mediated regulation and maintenance of the normal metabolic balance of cells. The novel phage defense strategy and regulation and maintenance of cellular metabolism effectively limited the expansion of the phage population.

Contamination of waters, soils, sediments and other environmental media by steroid estrogens is an emerging health issue because estrogens exhibit toxic effects on fishes and animals. Levels of steroid estrogens vary widely, ranging from below the detection limit to hundreds of nanograms per liter. Estrogens alter hormone levels and the homeostasis system of living organisms, they increase the risk of cardiovascular diseases, prostate cancer and breast cancer in humans and they may induce reproductive disorders, fetal malformations and feminization of males. Here, we review detection methods of steroid estrogens in water samples. Methods mainly include chemical analysis, immunoassays and bioassays. Advanced sensors increase the selectivity and sensitivity of electrochemical assays. For instance, graphene-based sensors can decrease the detection limit to 50 fM, though estrogen analogues may interfere. Immunoassays such as ELISA have the advantages of high sensitivity, fast analysis speed and wide applicability from 2 to 4000 ng/L, though it is susceptible to cross-reactivity.

Novel fluorescent nitrogen and phosphorus-doped carbon dots (Aa N,P-CDs) derived from Auricularia auricula were successfully prepared via a simple hydrothermal method. The Aa N,P-CDs showed high selectivity and sensitivity in detection of 4-nitrophenol (4-NP) and Ag(I) and good linear ranges of 4-NP (0–37.5 μM, R2 = 0.9967) and Ag(I) (0–25 μM, R2 = 0.9934). The low detection limits were 198 nM and 74.35 nM, respectively. This showed that static quenching dominated in Ag(I) quenching of the Aa N,P-CD fluorescence, while that of 4-NP was the inner filter effect. The Aa N,P-CDs were successfully used to detect 4-NP and Ag(I) in real water and soil samples. Cell imaging indicated that Aa N,P-CDs showed low biotoxicity and good biocompatibility, which provided a new insight into bioimaging application and environmental pollutant detection.

Carbon dots (CDs) have broad prospective applications in various fields, and expanding the applications of fluorescent CDs, especially for CDs derived from bacteria, is a major research goal. In this study, novel CDs derived from Escherichia coli BW25113 (WT) were successfully synthesized via a one-step hydrothermal method. Unlike previously developed CDs-E. coli, CDs-WT can be used for microbial imaging of both live and dead cells. We demonstrated the biocompatibility, excellent penetrability, and nontoxic characteristics of CDs-WT for use as fluorescent probes for bioimaging both in vitro and in vivo. Importantly, we provide the first demonstration of CDs-WT distribution in various organs of mice, including the ability to cross the blood-brain barrier and the potential for rapid excretion through the intestines. Additionally, CDs-WT can be instantly utilized as a fluorescent probe for the highly selective and rapid detection of p-nitrophenol (p-NP) by the inner filter effect, with a limit of detection for p-NP of 11 nM, the lowest value reported to date. Hence, our results demonstrate the feasibility of p-NP detection and extend the bio-imaging applications of CDs prepared from bacteria.

Lovastatin, a secondary metabolite isolated from fungi, is often used as a representative drug to reduce blood lipid concentration and treat hypercholesterolemia. Its structure is similar to that of HMG-CoA. Lovastatin inhibits the binding of the substrate to HMG-CoA reductase, and strongly competes with HMG-CoA reductase (HMGR), thereby exerting a hypolipidemic effect. Further, its safety has been confirmed in vivo and in vitro. Lovastatin also has anti-inflammatory, anti-cancer, and neuroprotective effects. Therefore, the biological activity of lovastatin, especially its anti-cancer effect, has garnered research attention. Several in vitro studies have confirmed that lovastatin has a significant inhibitory effect on cancer cell viability in a variety of cancers (such as breast, liver, cervical, lung, and colon cancer). At the same time, lovastatin can also increase the sensitivity of some types of cancer cells to chemotherapeutic drugs and strengthen their therapeutic effect. Lovastatin inhibits cell proliferation and regulates cancer cell signaling pathways, thereby inducing apoptosis and cell cycle arrest. This article reviews the structure, biosynthetic pathways, and applications of lovastatin, focusing on the anti-cancer effects and mechanisms of action.

As the most abundant biological entities on earth, bacteriophages (phages) were considered as the antagonists of bacteria. With the rapid development of genomics and molecular biology technologies, a subtle and complex relationship between phages and their host bacteria has been uncovered. Prophage refers to an intracellular form of a bacteriophage, which is usually integrated into the hereditary material of the host. Prophage is ubiquitously distributed in bacterial genomes. It reproduces when the host does and can affect important biological properties of their bacterial hosts, such as virulence, biofilm formation and host immunity. Interestingly, prophages were also involved in regulating the lysogeny-lytic state by "monitoring" the quorum sensing of bacteria. Recently, anti-CRISPR proteins encoded by prophages were found, which attracts a lot of attention. In this review, we summarized the prediction, distribution, classification and functions of prophages to lay a foundation for further studying interactions between phages and bacteria.噬菌体是地球上最多的生物实体,一直被认为是细菌的天敌。然而随着基因组学和分子生物学等技术的快速发展,人们发现噬菌体与宿主之间存在微妙而复杂的关系。前噬菌体是指溶原性细菌内存在的整套噬菌体DNA基因组,广泛分布在细菌基因组中,对调节细菌宿主生理具有重要作用,如参与调节宿主的毒力、影响生物膜形成、赋予宿主免疫力等。有趣的是,前噬菌体可以通过“监听”细菌的群体感应来调节自身的溶原-裂解状态。近年来,一些细菌中由前噬菌体编码的抗CRISPR蛋白的发现引起了人们对前噬菌体研究的关注。因此,对前噬菌体的研究可以为改造宿主和前噬菌体提供基础理论参考。本文对前噬菌体的预测、分布、分类及功能进行了综述,以期为进一步研究噬菌体与宿主间的关系提供基础。.

Among antibacterial nanomaterials, carbon dots (CDs) have attracted much attention because of their unique physical and chemical properties and good biosafety. In this study, kanamycin sulfate (Kan), a broad-spectrum antibiotic, was used to synthesize novel carbon dots (CDs-Kan) by a one-step hydrothermal method. CDs-Kan showed good inhibitory effects on Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Further, scanning electron microscopy revealed that treatment with CDs-Kan and Kan resulted in the same phenomena. In particular, the morphologies of S. aureus cells treated with CDs-Kan and Kan became smaller and irregular, whereas the surfaces of E. coli cells protruded and formed vesicles. These results indicated that CDs-Kan was shown to retain the good antibacterial activity of Kan as well as its main bactericidal functional groups, namely, the amino sugar and amino cyclic alcohol, We refer to this phenomenon as the "preservation property". We also found that CDs-Kan has good biocompatibility and nontoxic properties. Moreover, CDs-Kan was successfully applied to the biological imaging of fungi and plant cells. In addition, CDs-Kan could be used as a fluorescent probe for the quick, sensitive, and selective detection of Cr

Carbon dots (CDs) and photoluminescent carbon dots (Pn-CDs) are promising nanomaterials due to their bioimaging applications and have attracted considerable attention because of their excellent stability, good biocompatibility, and low biotoxicity. Here, the Pn-CDs and highly fluorescent nitrogen-doped CDs (Pn N-CDs) derived from Panax notoginseng were successfully synthesized by a simple hydrothermal method. Pn N-CDs exhibit optical properties and stability superior to those of Pn-CDs and can be better used as fluorescent dyes and probes in biological imaging. The obtained Pn N-CDs can be effectively applied to the imaging of bacteria, fungi, plant cells, and protozoa. In addition, Pn N-CDs can perform specific staining on the membranes of all tested cells. The in vivo imaging of mice revealed that Pn N-CDs exhibit nontoxicity and good biocompatibility and biodistribution. Furthermore, Pn N-CDs can be utilized as fluorescent probes for the rapid and highly selective detection of Cr

p-Nitrophenol (p-NP) pollutants are widely present in soil and aquatic environments and can seriously impair the health of living beings. Hence, a rapid, sensitive, and selective method for p-NP detection is urgently needed. Herein, for the first time, we successfully synthesized fluorescent carbon dots (CDs) from Bacillus cereus (BC) via a one-step hydrothermal process. The obtained CDs-BC can be applied as a rapid, highly selective, and sensitive sensor for p-NP detection. The fluorescence quenching efficiency of the CD-BC sensor exhibited excellent linear responses with p-NP concentrations at both 0.3-6.5 μM and 6.5-30 μM, with a detection limit of 0.11 μM. The mechanism of p-NP detection is based on the inner filter effect (IFE). Preliminary bacteria, cell, and animal studies showed that the as-prepared CDs-BC possess high photostability, excellent biocompatibility, low or no biotoxicity, and multicolor fluorescence emission properties; furthermore, they can be rapidly excreted from the body of mice, which suggests their potential for applications in the biomedical field.

Carbon dots (CDs) possess properties appropriate for application in various fields, especially in environmental pollution detection and biological imaging. With the unprecedented worsening of environmental quality, rapid identification and real-time monitoring of toxic compounds are very important. We successfully synthesized fluorescent CDs doped with tryptone and yeast extract via a hydrothermal process. The readily procured CDs-TY possess good photostability and can be applied as a probe for highly selective, rapid, and facile detection of both p-nitrophenol (p-NP) and Ni2+. The prepared CDs-TY display an excellent linear response to the concentrations of p-NP and Ni2+ in the range of 0.03–20 μM and 0.1–32 μM, respectively. The limit of detection (LOD) for p-NP was as low as 12 nM, which is lower than most reported values thus far. Additionally, HeLa cells and microbial cells were employed to explore the application of CDs-TY in bioimaging in vitro. CDs-TY exhibit excellent biocompatibility, and can be employed as fluorescent imaging dyes for the visualization of microbial (both live and dead) and HeLa cells. Interestingly, we also clearly observed that CDs-TY had no adverse effect on the growth and reproduction of microbes, which provides strong evidence regarding the biosafety of CDs-TY.

The human purinergic P2Y1 receptor (P2Y1R) belongs to the family of G-protein coupled receptors (GPCRs). Two stable cell lines, hP2Y1R-tGFP/U2OS and hP2Y1R-β-AR2-tGFP/U2OS, were generated with steady expression of fluorescent tGFP tagged P2Y1R or tGFP tagged β-arrestin2. The High Content Screening (HCS) technique was used to investigate P2Y1R mediated signal transduction processes based on the distribution of fluorescent receptors or the β-arrestin2/receptor complex. All procedures including aggregation, endolysis and resensitization that were involved in the interaction between the P2Y1 receptor and its ligand can be visualized using the tGFP labeled receptor combined with HCS technology in this study. ADP activated P2Y1R to induce a distinguished pattern of fluorescent vesicle formation inside both cell types. These two cell lines produced different peak fluorescence signals when activated by ADP at 100 μM, and the time to form the maximal vesicles was detected as 15 and 20 min respectively. The EC50 values of the concentration–response curves of ADP induced formation of fluorescent vesicles were 35.7 nM and 71.8 nM respectively. The ADP effects could be blocked by a P2Y1R specific antagonist MRS2179. The P2Y1R are coupled to Gq protein to activate PLC first, PLC cleave PIP2 into IP3 and DAG. And then DAG and Ca2+ activate PKC pathway, and finally the phospholipase D initiates β-arrestin2 mediated signal pathway. It took 30 and 45 min to complete P2Y1R re-sensitization in these two constructs respectively. Our results demonstrated that P2Y1R triggered downstream responses not only via heterotrimeric Gq proteins but also through β-arrestin2.

There is still no satisfying method to treat colorectal cancer (CRC) currently. Inspired by cocktail therapy, the combination of 465 nm blue LED irradiation and two multi-target anticancer agents AT406 and Rocaglamide has been investigated as an innovative way to treat colorectal cancer cells in vitro. It showed a strong inhibitory effect on colorectal cancer cells, and its side effects on human normal cells are negligible. When applied to HCT116 cells, it can achieve an apoptotic rate up to 95%. It is also seen to significantly inhibit proliferation of HT29 cells. Furthermore, little to no cell inhibition or damage of normal MRC-5 cells were seen after treatment. The combination of blue LED irradiation and two anti-cancer drugs causes apoptosis of colorectal cancer cells by activating the apoptotic pathway, inhibiting autophagy and proliferation pathways as well as the production of reactive oxygen species (ROS).

The Mingyong Glacier is located in the northwest of Yunnan Province, China. The area, including the cold temperate zone, the middle temperate zone, and the warm temperate zone, is a typical vertical climate zone. To explore new classification and identification methods for cold-adapted bacteria in this area, the Sherlock automated microbial identification system (MIDI, Inc., Newark, DE, United States) and 16S rRNA gene sequencing was used. Phylogenetic analysis showed that for cold-adapted bacteria the analysis by unsaturated fatty acids in membranes provided more precise taxonomic information than 16S rRNA gene analysis, which is sensitive enough to distinguish cold-adapted bacteria at the same genus level. The results also demonstrated that the proportion of unsaturated fatty acids in those cold-adapted bacterial cell membranes was inversely proportional to temperature. Although most of the unsaturated fatty acid composition was similar to other reported cold-adapted bacteria, the fatty acid composition of some of the cold-adapted bacteria was not the same, which warrants further study.

Summary Endophytic fungal communities of Dysphania ambrosioides, a hyperaccumulator growing at two Pb‐Zn‐contaminated sites, were investigated through culture‐dependent and culture‐independent approaches. A total of 237 culturable endophytic fungi (EF) were isolated from 368 tissue (shoot and roots) segments, and the colonization rate (CR) ranged from 9.64% to 65.98%. The isolates were identified to 43 taxa based on morphological characteristics and rDNA ITS sequence analysis. Among them, 13 taxa (30.23%) were common in plant tissues from both sites; however, dominant EF were dissimilar. In culture‐dependent study, 1989 OTUs were obtained through Illumina Miseq sequencing, and dominant EF were almost same in plant tissues from both sites. However, some culturable EF were not observed in total endophytic communities. We suggest that combination of both culture‐dependent and culture‐independent methods will provide more chances for the precise estimation of endophytic fungal community than using either of them. The tissue had more influence on the culturable fungal community structure, whereas the location had more influence on the total fungal community structure (including culturable and unculturable). Both culture‐dependent and culture‐independent studies illustrated that endophytic fungal communities of D. ambrosioides varied across the sites, which suggested that HM concentration of the soil may have some influence on endophytic fungal diversity.

Curcumin, a phytochemical derived from the rhizome of turmeric (Curcuma longa L.), has a broad group of substances with antibacterial, anti-inflammatory, anti-oxidant, anticancer activities. The anticancer activity of curcumin and its derivatives are mainly related to its regulation of signal transduction pathways. However, due to the low oral availability of curcumin, fast metabolism and other pharmacokinetic properties limit the application of curcumin in the treatment of cancer. Evidence suggests that curcumin combined with photodynamic therapy can overcome the limitation of curcumin's low bioavailability by acting on apoptosis pathways, such as B-cell lymphoma 2 (Bcl-2) and caspase family, and affecting cell cycle. This paper reviews the structure and pharmacokinetics of curcumin, focusing on the anticancer activity of curcumin combined with photodynamic therapy and the effects on cancer-related signal pathways.