L-Arginine-Loaded Gold Nanocages Ameliorate Myocardial Ischemia/Reperfusion Injury by Promoting Nitric Oxide Production and Maintaining Mitochondrial Function.

Cardiovascular disease is the leading cause of death worldwide. Reperfusion therapy is vital to patient survival after a heart attack but can cause myocardial ischemia/reperfusion injury (MI/RI). Nitric oxide (NO) can ameliorate MI/RI and is a key molecule for drug development. However, reactive oxygen species (ROS) can easily oxidize NO to peroxynitrite, which causes secondary cardiomyocyte damage. Herein, L-arginine-loaded selenium-coated gold nanocages (AAS) are designed, synthesized, and modified with PCM (WLSEAGPVVTVRALRGTGSW) to obtain AASP, which targets cardiomyocytes, exhibits increased cellular uptake, and improves photoacoustic imaging in vitro and in vivo. AASP significantly inhibits oxygen glucose deprivation/reoxygenation (OGD/R)-induced H9C2 cell cytotoxicity and apoptosis. Mechanistic investigation revealed that AASP improves mitochondrial membrane potential (MMP), restores ATP synthase activity, blocks ROS generation, and prevents NO oxidation, and NO blocks ROS release by regulating the closing of the mitochondrial permeability transition pore (mPTP). AASP administration in vivo improves myocardial function, inhibits myocardial apoptosis and fibrosis, and ultimately attenuates MI/RI in rats by maintaining mitochondrial function and regulating NO signaling. AASP shows good safety and biocompatibility in vivo. This findings confirm the rational design of AASP, which can provide effective treatment for MI/RI.

Light-triggered photosynthetic engineered bacteria for enhanced-photodynamic therapy by relieving tumor hypoxic microenvironment.

Background: Singlet oxygen (1O2) has received considerable research attention in photodynamic therapy (PDT) due to its cytotoxic solid features. However, the inherent hypoxic state of the tumor microenvironment (TME) leads to the meager 1O2 quantum yield of inorganic PDT reagents, and their application in vivo remains elusive. Methods: We developed a novel strategy to fabricate active photosynthetic bacteria/photosensitizer/photothermal agent hybrids for photosynthetic tumor oxygenation and PDT and PTT tumor therapy under different laser irradiation sources. Photosynthetic bacteria combined with Ce6 photosensitizer and Au NPs photothermal agent, the obtained Bac@Au-Ce6 effectively targets tumor tissues and further enhances the tumor accumulation of Au-Ce6. Results: The results showed that the Au-Ce6-loaded engineered bacteria (Bac@Au-Ce6) maintained the photosynthetic properties of Syne. After i.v. injection, Bac@Au-Ce6 efficiently aggregates at tumor sites due to the tumor-targeting ability of active Syne. With 660 nm laser irradiation at the tumor site, the photoautotrophic Syne undergoes sustained photosynthetic O2 release and immediately activates O2 to 1O2 via a loaded photosensitizer. PTT was subsequently imparted by 808 laser irradiations to enhance tumor killing further. Conclusions: This work provides a new platform for engineering bacteria-mediated photosynthesis to promote PDT combined with PTT multi-faceted anti-tumor.

The leucine-responsive regulatory protein SCAB_Lrp modulates thaxtomin biosynthesis, pathogenicity, and morphological development in Streptomyces scabies.

Streptomyces scabies is the best-characterized plant-pathogenic streptomycete, which is a special species among the large genus Streptomyces. The pathogenicity of S. scabies relies on the production of the secondary metabolite thaxtomin A. Little is known about the molecular mechanisms underlying the regulation of thaxtomin biosynthesis in S. scabies beyond the pathway-specific activator TxtR and the cellulose utilization repressor CebR. The leucine-responsive regulatory protein (Lrp) family modulates secondary metabolism in nonpathogenic streptomycetes. However, the regulatory relationship between the Lrp and pathogenic streptomycetes remains unknown. In this study, we demonstrated that SCAB_Lrp (SCAB_77931) from S. scabies significantly affects thaxtomin biosynthesis, pathogenicity, and morphological development. SCAB_Lrp deletion resulted in a dramatic decline in thaxtomin A production and a low-virulence phenotype of S. scabies. An in-depth dissection of the regulatory mechanism of SCAB_Lrp revealed that it positively regulates the transcription of the thaxtomin biosynthetic gene cluster by directly binding to the promoter of the cluster-situated regulator gene txtR. SCAB_Lrp also controls the morphological development of S. scabies by directly activating the transcription of amfC, whiB, and ssgB. SCAB_Lrp directly controls the transcription of its own gene by binding a specific sequence (5'-GGACAGTCGCCGTGCTACG-3'). Moreover, phenylalanine and methionine have been characterized as SCAB_Lrp effectors by strengthening the binding affinity and complex status between SCAB_Lrp and DNA. Our findings characterize a multifunctional regulatory protein, SCAB_Lrp, that controls secondary metabolism, pathogenicity, and sporulation in S. scabies and provide new insights into the complex regulatory network that modulates thaxtomin phytotoxins in pathogenic Streptomyces.

Live bio-nano-sonosensitizer targets malignant tumors in synergistic therapy.

Sonosensitizers that can increase the concentration of reactive oxygen species (ROS) within a tumor microenvironment is a high priority for sonodynamic therapy (SDT). In this study, a functionalized, smart nanosonosensitizer based on Au-RuO2 nanoparticles (NPs) and selenium nanoparticles (Se NPs) that were electrostatically self-assembled onto the surface of Listeria innocua (LI) was used to create Bac@ARS. Au NPs provided the core in which RuO2 was deposited to form Au-RuO2 NPs. Additionally, the underlying properties of the Au NPs and Se NPs were used to optimize the sonosensitivity performance. Compared with pristine RuO2 NPs, Bac@ARS exhibits highly efficient ROS-producing activity. Furthermore, Bac@ARS remodeled the hypoxic tumor microenvironment, enabling overproduction of ROS. Importantly, Bac@ARS exploits the natural tropism of LI to selectively accumulate in tumors, which improved the treatment precision at hypoxic tumor sites after sonodynamic activation. However, the activity of LI was greatly reduced after ultrasound (US) irradiation, ensuring the biosafety of Bac@ARS. Bac@ARS was also used to monitor tumors, in real time, using photoacoustic imaging of the gold-based nanoparticles. Therefore, Bac@ARS is a promising microbial sonosensitizer providing a new platform for the optimization of sonosensitizers for tumor treatment. STATEMENT OF SIGNIFICANCE: A bio-nano-sonosensitizer was designed using a Au nanoparticle (NP) core modified with RuO2 NPs. The Au-RuO2 NPs together with Se-NPs are attached via electrostatic adsorption to a live bacterium Listeria innocua (LI), creating Bac@ARS. The role of the NPs was to optimize the sonosensitivity performance at the target tumor site. Bac@ARS reshaped the tumor microenvironment and overcame tumor hypoxia leading to ROS overproduction. This activated a potent ICD-mediated cellular immunity and anti-tumor activity. Importantly, Bac@ARS exploited the natural tropism of LI to selectively accumulate in tumors, resulting in more precise delivery of the therapeutic effect while exhibiting reduced effects on healthy tissues.

Multiple responses optimization of antioxidative components extracted from Fenugreek seeds using response surface methodology to identify their chemical compositions.

Fenugreek seeds (Trigonella foenum-graecum L.), one kind of traditional Chinese medicine, are reported to be of great potential as a new alternative in terms of their bioactive components. In our present study, an ultrasonic-assisted method was applied in the extraction of antioxidative components from fenugreek seeds. Four factors: ethanol concentration, liquid-solid ratio, sonication time, and sonication power were selected and multiple responses were studied using the response surface methodology (RSM). The effects of factors along with the correlation between all responses (flavonoids content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, OH- assay) were studied. The regression model indicated that all four factors are of significant effect on all responses. The model predicted that the ethanol concentration of 72%, solvent-to-material ratio of 35 ml/g, ultrasonic time of 41 min, and 500 W of power would provide a flavonoid yield of 9.10 mg/g, DPPH clearance of 80.33%, and OH- clearance of 24.28%, respectively. The confirmation test showed the closeness of the predicted results with those of experimental values. And AB-8 resin was successfully used to purify the fenuellus hulusi seed extract, and the flavonoid concentration of 78.14% was obtained. Six flavonoids (Swertisin, Puerarin apioside, Jasminoside B, Astragalin, Apigenin-7-O-beta-D-glucoside, and Apiin) were successfully identified by the liquid chromatography-mass spectrometry (LC-MS) analysis.

A rational design of copper-selenium nanoclusters that cures sepsis by consuming endogenous H2S to trigger photothermal therapy and ROS burst.

The treatment of sepsis caused by bacterial infections is still a huge clinical challenge. As sepsis causes high levels of endogenous H2S in vivo, researchers can design nanomedicines to treat sepsis by in situ sulfurization. Here, we designed and synthesized Cu2O-coated non-metallic core-shell selenium nanoparticles. To cure mice sepsis by ROS burst. Our experimental data displayed that the photothermal effect of Se@Cu9S8 produced by the reaction of Se@Cu2O and endogenous H2S is synergistically antibacterial, and Se@Cu2O has the characteristics of low side effects and high biocompatibility. In summary, our research results verified our design, that copper-selenium nanoclusters may be an efficient strategy to cure sepsis by in situ sulfurization of endogenous H2S, triggering ROS eruptions and photothermal therapy.

Rhizobium cremeum sp. nov., isolated from sewage and capable of acquisition of heavy metal and aromatic compounds resistance genes.

Two strains of Rhizobia isolated from sewage collected from the Chinese Baijiu distillery were characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains W15T and W16 were grouped as a separate clade closely related to Rhizobium daejeonense L61T (98.6%). Multilocus sequence analysis (MLSA) with three housekeeping genes (recA, glnII and rpoA) also showed that strains W15T and W16 belonged to the genus Rhizobium. Average nucleotide identity and digital DNA-DNA hybridization values between genome sequences of strain W15T and the closely related species ranged from 77.0% to 87.8% and from 23.9% to 30.9%. The DNA G + C content of strain W15T was 61.6 mol%. Strain W15T contained Q-10 as the major ubiquinone and the dominant fatty acids were summed feature 8 (C 18:1ω7c and/or C 18:1ω6c; 73.1%) and C18:0 (7.6%). The main polar lipids are phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. On the basis of the evidences presented in this study, strains W15T and W16 represents a novel species of the genus Rhizobium, for which the name Rhizobium cremeum sp. nov. is proposed. The type strain is W15T (= CGMCC 1.18731T = KACC 22344T).

Efficient sterilization system combining flavonoids and hyaluronic acid with metal organic frameworks as carrier.

Bacterial infections can cause many human diseases, which are closely related to people's health. Nowadays, antibiotics are mainly used to treat bacterial infections, but the widespread use of antibiotics can also lead to bacterial resistance. Therefore, effective treatment of bacterial infections is an urgent problem to be solved. In this article, a multifunctional therapeutic material with antibacterial properties was designed and synthesized. First, the porous media material ZIF-8 was synthesized, and applied to load hesperidin. When the load is completed, a layer of hyaluronic acid (HA) is uniformly wrapped on surface of the material. Such materials have high stability and high drug-carrying capacity, and can be slowly released in vivo. The HA coated on surface can also promote penetration of active ingredients into cells and give full play to antibacterial ability. Results of in vitro and in vivo antibacterial tests show that synergy between the materials enhances antibacterial activity which is related to dose. The material achieves high-efficiency antibacterial effects by increasing the permeability of cell membranes and destroying the integrity of bacteria. At same time, the material does not show obvious side effects. Therefore, the material seems to be a promising antibacterial agent with good biocompatibility and strong antibacterial activity.

Lowered Cd toxicity, uptake and expression of metal transporter genes in maize plant by ACC deaminase-producing bacteria Achromobacter sp.

In this study, an ACC deaminase-producing bacterial strain Achromobacter sp. A1 was isolated from maize rhizosphere soil, characterized and evaluated for the effects on cadmium (Cd) immobilization in solution/rhizosphere, physiological characteristics and the tissue Cd contents in maize and the molecular mechanisms involved by hydroponic and pot experiments. ACC deaminase activity of strain A1 was significantly enhanced by Cd addition and Cd concentration decreased (55.54-63.62%) in solution supplemented with various Cd concentrations. Strain A1 significantly increased the maize dry weights (30.77-105%) and chlorophyll content (7.46-14.46%), decreased MDA content (25.16-36.87%) and ethylene production (20.93-35.86%) in hydroponic experiment. Strain A1 significantly reduced the above-ground tissue Cd uptake by 12.64-33.68% and 42-48% in hydroponic and pot experiments, reduced the DTPA-extractable Cd content and elevated invertase, urease and catalase activity in rhizosphere soils. In addition, the expression levels of Cd transporter genes HMA3 and Nramp5 were significantly reduced in root and shoot after strain A1 inoculation. These results indicate that strain A1 has great potential for application as a novel and environmentally friendly inoculant to immobilize Cd and reduce maize Cd uptake in Cd-contaminated environments, and will improve the understanding of the relative molecular mechanisms underlying the response to strain A1 in maize plant.

Crystalline ruthenium polypyridine nanoparticles: a targeted treatment of bacterial infection with multifunctional antibacterial, adhesion and surface-anchoring photosensitizer properties.

Photodynamic antibacterial therapy employs nanocomposites as an alternative to traditional antibiotics for the treatment of bacterial infections. However, many of these antibacterial materials are less effective towards bacteria than traditional drugs, either due to poor specificity or antibacterial activity. This can result in needless and excessive drug use in treatments. This paper describes a multifunctional drug delivery nanoparticle (MDD-NP), Sph-Ru-MMT@PZ, based on the nanostructured-form of [Ru(bpy)2dppz] (PF6)2 (Sph-Ru), which has adhesive properties towards its microbial targets as well as surface-anchoring photosensitizer effects. The design and construction of MDD-NP is based on the adhesive properties of the outer layers of montmorillonite (MMT), which allows Sph-Ru-MMT@PZ to successfully reach its bacterial target; the outer layer of the E. coli. In addition, under 670 nm red irradiation therapy (R-IT), the surface-anchoring properties use the photosensitizer phthalocyanine zinc (PZ) to destroy the bacteria by producing reactive oxygen species (ROS) which causes cell lysis of E. coli. More importantly, Sph-Ru-MMT@PZ has no fluorescence response to live E. coli with intact cell membranes but selectively stained and demonstrated fluorescence during membrane damage of early-stage cells as well as exposure of nuclear materials at late-stage of cell lysis. Sph-Ru-MMT@PZ showed beneficial and synergistic anti-infective effects in vivo by inhibiting the E. coli infection-induced inflammatory response and eventually promoting wound healing in mice. This new strategy for high precision antibacterial therapy towards specific targets, provides an exciting opportunity for the application of multifunctional nanocomposites towards microbial infections.

Joint engineering of SACE_Lrp and its target MarR enhances the biosynthesis and export of erythromycin in Saccharopolyspora erythraea.

The Lrp and MarR families are two groups of transcriptional regulators widely distributed among prokaryotes. However, the hierarchical-regulatory relationship between the Lrp family and the MarR family remains unknown. Our previous study found that an Lrp (SACE_Lrp) from Saccharopolyspora erythraea indirectly repressed the biosynthesis of erythromycin. In this study, we characterized a novel MarR family protein (SACE_6745) from S. erythraea, which is controlled by SACE_Lrp and plays a direct regulatory role in erythromycin biosynthesis and export. SACE_Lrp directly regulated the expression of marR by specifically binding a precise site OM (5'-CTCCGGGAACCATT-3'). Gene disruption of marR increased the production of erythromycin by 45% in S. erythraea A226. We found that MarR has direct DNA-binding activity for the promoter regions of the erythromycin biosynthetic genes, as well as an ABC exporter SACE_2701-2702 which was genetically proved to be responsible for erythromycin efflux. Disruption of SACE_Lrp in industrial S. erythraea WB was an efficient strategy to enhance erythromycin production. Herein, we jointly engineered SACE_Lrp and its target MarR by deleting marR in WBΔSACE_Lrp, resulting in 20% increase in erythromycin yield in mutant WBΔLrpΔmarR compared to WBΔSACE_Lrp, and 39% to WB. Overall, our findings provide new insights into the hierarchical-regulatory relationship of Lrp and MarR proteins and new avenues for coordinating antibiotic biosynthesis and export by joint engineering regulators in actinomycetes. KEY POINTS: • The hierarchical-regulatory relationship between SACE_Lrp and MarR was identified. • MarR directly controlled the expression of erythromycin biosynthesis and export genes. • Joint engineering of SACE_Lrp-MarR regulatory element enhanced erythromycin production.

Human small intestine cancer cell membrane-camouflaged quercetin-melanin for antibacterial and antitumor activity.

E. coli has become an important factor that can lead to cancer because of its ability to cause diverse intestinal changes. Nano-polymer materials provide ideal drug delivery systems for preparing antibacterial and anti-cancer drugs because of their unique structure, easy modification, and high drug loading. The modified natural melanin has the potential to be an excellent nano-carrier. By improving the water-solubility and biocompatibility of the loaded natural drug quercetin, the antibacterial effect of quercetin can be fully played. Here, natural melanin was extracted from frozen squid to synthesize carrier polydopamine (PDA) nanoparticles, and the natural drug quercetin (Q) was modified on the surface of PDA by π-π bond and covalent bond action to produce melanin-quercetin (PDA-Q). We also developed human small intestinal cancer cells (HIC) membrane-camouflaged melanin-Quercetin (PDA-Q) nanoparticles as an anti-cancer platform in vivo. The potential bacteriostatic mechanism was likely driven by the penetration of PDA-Q in E. coli cells, damaging the integrity of the membranes of E. coli and inducing cell death. The mice wound experiment and bacteremia model experiment revealed that C@PDA-Q had a strong inhibitory effect on E. coli in vivo. In addition, the results of the in vitro tumor test also revealed that C@PDA-Q had strong anti-tumor activity against HIC cells of human small intestinal cancer, and the IC50 value was 12.3 ± 0.7 µg/ml, which was slightly better than that for cisplatin. As both melanin nanoparticles and HIC membrane are natural biomaterials, the synthesized C@PDA-Q nano-polymer material shows great potential for use in anti-cancer nano-drug loading.

Enantiomeric selectivity of ruthenium (II) chiral complexes with antitumor activity, in vitro and in vivo.

Different enantiomers of chiral drugs show distinctive activities. Here, a pair of chiral ruthenium Λ-[Ru(phen)2(TPEPIP)]2+ (Λ-Ru), and Δ-[Ru(phen)2(TPEPIP)]2+ (Δ-Ru) (phen = 1,10-phenanthroline; TPEPIP = 2-(4'-(1,2,2-triphenylvinyl)-[1,1'-biphenyl]-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline) compounds have been prepared and characterized. Both have aggregation-induced emission characteristics, although Λ-Ru exhibits much higher activity, towards duplex DNA extracted from SGC-7901 cancer cells. In vitro experiments demonstrate that both Λ-Ru and Δ-Ru can induce the apoptosis of tumor cells with Λ-Ru showing greater activity than Δ-Ru. Λ-Ru aggregates in the cell nucleus of SGC-7901 within 5 h which shows that nucleic acids may be the effective target of Λ-Ru. In vivo experiments with nude mice showed that Λ-Ru can inhibit the growth and proliferation of a tumor, in tumor-bearing mice as well as targeting the tumor site, as demonstrated by fluorescence. These results demonstrate the dual-function of Λ-Ru, which could be used for real-time visualization of a chemotherapeutic agent.

Designing Aptamer-Gold Nanoparticle-Loaded pH-Sensitive Liposomes Encapsulate Morin for Treating Cancer.

This study proposes the synthesis of a type of anticancer nanoparticle, aptamers and Au nanoparticle (Apt-Au)-modified Morin pH-sensitive liposome (MSL), which exhibits targeting properties. Tumors are difficult to cure because their microenvironment varies from that of normal tissue; its pH is lower than that of normal tissue, which generally impedes the effectiveness of drugs. Thus, pH-responsive drugs have attracted extensive attention. Gold nanoparticles (AuNPs) show potential as drug carriers because of their small size, good biocompatibility, easy surface modification, and strong cell penetration. Apt-Au@MSL exhibits excellent monodispersity and tumor-targeting properties and can be released in partly acidic environment via dialysis. We screened our model cancer cell by MTT assay and found that SGC-7901 cells can effectively suppress proliferation. In vivo results demonstrate that the administration of Apt-Au@MSL could inhibit tumor growth in xenograft mouse models. H&E staining and TUNEL assay further confirmed that Apt-Au@MSL can promote tumor apoptosis. Apt-Au@MSL may induce apoptosis by triggering overproduction of reactive oxygen species (ROS) and regulating multiple signal crosstalk. Both blood biochemistry tests and H&E staining suggested that these materials exhibit negligible acute toxicity and good biocompatibility in vivo. With its powerful function, Apt-Au@MSL can be used as a target-based anticancer material for future clinical cancer treatment.

Antibacterial activity of chlorogenic acid-loaded SiO2 nanoparticles caused by accumulation of reactive oxygen species.

Diseases caused by pathogenic bacilli pose an increasing threat to human health. A common feature of these bacteria is a complete cell wall; therefore, drugs that can penetrate this protective barrier could be used as a novel approach for treating these infections. Here we present a simple method for synthesizing a silica mesoporous material loaded with cadmium selenide (CdSe) and chlorogenic acid. Using UV-visible, fluorescence, and infrared imaging in combination with transmission electron microscopy, it was shown that CdSe and chlorogenic acid could be successfully embedded in the mesopores of silica nanoparticles (CSC NPs), and these NPs presented with a strong fluorescence, uniform size, and good dispersion. Additionally, the results of these analyses indicated that the fluorescence of the CSC NPs was localized within the cells of Escherichia coli and Bacillus subtilis, signifying that these NPs could breach the cell wall and enter the cells of these two bacilli. Additional assessments found that these CSC NPs inhibited the proliferation of the bacteria by disrupting the cell wall, and this was most likely due to the overproduction of reactive oxygen species induced by chlorogenic acid. Importantly, histopathology analysis indicated that the CSC NPs had limited side effects and high biocompatibility.

Chitosan-catechin coating as an antifungal and preservable agent for postharvest satsuma oranges.

The antifungal properties of chitosan-catechin coating and the effect of fruit preservation were studied. We used catechin to modify chitosan to prepare a coating. The purpose of the study was to use chitosan-catechin coating to prolong the preservation time of satsuma oranges. In vitro experiments, the results showed that the antifungal activity of chitosan-catechin increased with increasing concentration, and the results are also significantly effect of comparing to chitosan and catechin alone (*p < 0.05). In vivo studies, chitosan-catechin coating treatment significantly reduced rot caused by Penicillium Citrinum and Aspergillus niger. The physiological and biochemical indexes of the chitosan-catechin coating treatment group were significantly higher than those of the control group (*p ≤ 0.05). In the toxicity test, mice injected with chitosan-catechin solution showed no significant difference compared to the control group. These results indicate that this chitosan-catechin coating may be useful as an antifungal and preserving agent for satsuma oranges. PRACTICAL APPLICATIONS: The fruit after harvest every year is a large loss due to improper storage, and the preservation of fruits is an effective way to reduce losses. The traditional fruit wrap is not degradable, and the preservation effect is relatively general. The chitosan film is a new type of edible fruit wrap, which has the advantages of being edible and easily degradable, and can effectively reduce environmental pollution. Adding catechin to the preparation process of chitosan film can better improve the fresh-keeping effect and prolong the preservation time of the fruit.

Massilia atriviolacea sp. nov., a dark purple-pigmented bacterium isolated from soil.

A bacterial strain, designated SODT, with Gram-stain-negative and motile rod-shaped cells, was isolated from soil in Hefei, PR China, and was characterized using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SODT belonged to the genus Massilia and showed the highest similarities to Massilia violaceinigra B2T (99.3 %), followed by Massilia glaciei B448-2T (98.7 %), Massilia eurypsychrophila CGMCC 1.12828T (98.6 %) and Rugamonas rubra CCM3730T (97.8 %). Average nucleotide identity and digital DNA-DNA hybridization values between genome sequences of strain SODT and the closely related species ranged from 77.1 to 89.3% and from 22.2 to 34.7 %. The DNA G+C content of strain SODT was 65.4 mol%. Strain SODT contained Q-8 as the major ubiquinone and the dominant fatty acids were summed feature 3 (C16 : 1ω7c and/or C15 : 0iso 2-OH; 58.5 %), C16 : 0 (26.8 %) and C18 : 1ω7c (5.0 %). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. On the basis of the evidence presented in this study, strain SODT represents a novel species of the genus Massilia, for which the name Massiliaatriviolacea sp. nov. is proposed. The type strain is SODT (=KCTC 62720T=LMG 30840T).

Characterization and engineering of the Lrp/AsnC family regulator SACE_5717 for erythromycin overproduction in Saccharopolyspora erythraea.

In this work, we found that the Lrp/AsnC family protein SACE_5717 negatively regulated erythromycin biosynthesis in S. erythraea. Disruption of SACE_5717 led to a 27% improvement in the yield of erythromycin in S. erythraea A226. SACE_5717 directly repressed its own gene expression, as well as that of the adjacent gene SACE_5716 by binding to the target sequence 5'-GAACGTTCGCCGTCACGCC-3'. The predicted LysE superfamily protein SACE_5716 directly influenced the export of lysine, histidine, threonine and glycine in S. erythraea. Arginine, tyrosine and tryptophan were characterized as the effectors of SACE_5717 by weakening the binding affinity of SACE_5717. In the industrial S. erythraea WB strain, deletion of SACE_5717 (WBΔSACE_5717) increased erythromycin yield by 20%, and by 36% when SACE_5716 was overexpressed in WBΔSACE_5717 (WBΔSACE_5717/5716). In large-scale 5-L fermentation experiment, erythromycin yield in the engineered strain WBΔSACE_5717/5716 reached 4686 mg/L, a 41% enhancement over 3323 mg/L of the parent WB strain.

Self-assembled thermal gold nanorod-loaded thermosensitive liposome-encapsulated ganoderic acid for antibacterial and cancer photochemotherapy.

A novel nanoparticle (Au-LTSL-GA.A) uses the thermosensitive liposome (LTSL) to encapsulate ganoderic acid A (GA.A), which successfully transforms the polarity of GA.A and has excellent water solubility. The multifunctional Au-LTSL-GA.A, a self-assembled thermal nanomaterial, was used in antibacterial and anticancer applications in combination with near-infrared (NIR) irradiation. The designed Au-LTSL-GA.A nanoparticle was used as a nano-photosensitizer to achieve synergistic photochemotherapy based on the phototherapy sensitization property of Au nanorods (NRs) and antitumour activity of GA.A. In the antibacterial experiments, the Au-LTSL-GA.A + NIR irradiation had a broad-spectrum antibacterial effect, exhibiting a strong antibacterial activity against drug-resistant Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) compared with the raw GA.A and LTSL-GA.A. In the anticancer experiments, Au-LTSL-GA.A + NIR irradiation, which combined phototherapy sensitization property of Au NRs with antitumour activity of GA.A, exhibited high anticancer activity against MCF-7 cells. The IC50 value of Au-LTSL-GA.A + NIR irradiation (12.1 ± 1.3 µg/mL) was almost similar to cisplatin in MCF-7 cells. The evaluation of the potential in vivo toxicity of Au-LTSL-GA.A revealed no toxicity in mice. The results of this study suggest that Au-LTSL-GA.A has a wide range of potential industrial and clinical applications, such as in antibacterial treatment and cancer photochemotherapy.