Effect of Treating Acid Sulfate Soils with Phosphate Solubilizing Bacteria on Germination and Growth of Tomato (Lycopersicon esculentum L.).

Acid sulfate soils contain sulfide minerals that have adverse environmental effects because they can lead to acidic drainage and prevent the establishment of vegetation. The current study examined the effect of a novel method for the restoration of these soils and the promotion of germination and plant growth. Thus, we isolated two strains of phosphate solubilizing bacteria, Methylobacterium sp. PS and Caballeronia sp. EK, characterized their properties, and examined their effects in promoting the growth of tomato plants (Lycopersicon esculentum L.) in acid sulfate soil. Compared with untreated control soil, treatment of acid sulfate soils with these bacterial strains led to increased seed germination, growth of plants with more leaves, and plants with greater levels of total-adenosine tri-phosphate (tATP). Relative to the untreated control soil, the addition of Caballeronia sp. EK led to a 60% increase in seed germination after 52 days, growth of plants with more than 3 times as many leaves, and a 45.2% increase in tATP after 50 days. This strain has potential for use as a plant biofertilizer that promotes vegetation growth in acid sulfate soils by improving the absorption of phosphorous.

Synthesis of nickel/biochar composite from pyrolysis of Microcystis aeruginosa and its practical use for syngas production.

This study proposes a sustainable waste-to-energy/biochar platform using a toxic microalgal biomass waste. In particular, CO2-feeding pyrolysis of Microcystis aeruginosa (M. aeruginosa) waste was investigated, focusing on the analysis of gaseous pyrolysates and properties of biochar with a construction of mass balance. Also, the catalytic capability of biochar produced from M. aeruginosa was explored to reinforce the mechanistic impact of CO2 on the pyrolysis process within the overall process level. Ni impregnated biochar composite was further synthesized and used as a catalyst to promote syngas formation in the CO2-feeding pyrolysis process of M. aeruginosa.

Interaction of Sb(III) with iron sulfide under anoxic conditions: Similarities and differences compared to As(III) interactions.

This study examined the reaction mechanism of arsenite, As(III), and antimonite, Sb(III), with iron sulfide and compared their pH-dependent reaction behaviors under strictly anoxic environments. The comparison of Sb(III) with As(III), based on their chemical similarity, may provide useful insight into understanding the geochemical behavior of the less studied Sb(III). The pH-dependent batch sorption studies revealed that As(III) and Sb(III) displayed similar removal trends with pH in terms of the removal efficiency. However, the aqueous As(III) species transformed to thioarsenite species, while aqueous Sb(III) species remained inert under the highly sulfidic anoxic system. An X-ray absorption spectroscopy study demonstrated the reaction of As(III) and Sb(III) at acidic pH was closely related to the precipitation of sulfide minerals As2S3 and Sb2S3, respectively, as a consequence of the reaction with sulfide produced through mackinawite dissolution. Meanwhile, the removal at basic pH was inferred as a surface reaction, possibly through surface complexation, surface-precipitation, or both. In this study, the pH-dependent Sb(III) uptake mechanisms proved to be similar to the corresponding mechanisms for As(III) uptake, with mackinawite demonstrating a superior capacity to scavenge Sb(III) in ferrous and sulfide-rich reducing environments.

A Human Antibody That Binds to the Sixth Ig-Like Domain of VCAM-1 Blocks Lung Cancer Cell Migration In Vitro.

Vascular cell adhesion molecule-1 (VCAM-1) is closely associated with tumor progression and metastasis. However, the relevance and role of VCAM-1 in lung cancer have not been clearly elucidated. In this study, we found that VCAM-1 was highly overexpressed in lung cancer tissue compared with that of normal lung tissue, and high VCAM-1 expression correlated with poor survival in lung cancer patients. VCAM-1 knockdown reduced migration of A549 human lung cancer cells into Matrigel, and competitive blocking experiments targeting the Ig-like domain 6 of VCAM-1 (VCAM-1-D6) demonstrated that the VCAM-1-D6 domain was critical for VCAM-1 mediated A549 cell migration into Matrigel. Next, we developed a human monoclonal antibody specific to human and mouse VCAM-1-D6 (VCAM-1-D6 huMab), which was isolated from a human synthetic antibody library using phage display technology. Finally, we showed that VCAM-1-D6 huMab had a nanomolar affinity for VCAM-1-D6 and that it potently suppressed the migration of A549 and NCI-H1299 lung cancer cell lines into Matrigel. Taken together, these results suggest that VCAM-1-D6 is a key domain for regulating VCAM-1-mediated lung cancer invasion and that our newly developed VCAM-1-D6 huMab will be a useful tool for inhibiting VCAM-1-expressing lung cancer cell invasion.

Oxidizing capacity of periodate activated with iron-based bimetallic nanoparticles.

Nanosized zerovalent iron (nFe0) loaded with a secondary metal such as Ni or Cu on its surface was demonstrated to effectively activate periodate (IO4-) and degrade selected organic compounds at neutral pH. The degradation was accompanied by a stoichiometric conversion of IO4- to iodate (IO3-). nFe0 without bimetallic loading led to similar IO4- reduction but no organic degradation, suggesting the production of reactive iodine intermediate only when IO4- is activated by bimetallic nFe0 (e.g., nFe0-Ni and nFe0-Cu). The organic degradation kinetics in the nFe0-Ni(or Cu)/IO4- system was substrate dependent: 4-chlorophenol, phenol, and bisphenol A were effectively degraded, whereas little or no degradation was observed with benzoic acid, carbamazepine, and 2,4,6-trichlorophenol. The substrate specificity, further confirmed by little kinetic inhibition with background organic matter, implies the selective nature of oxidant in the nFe0-Ni(or Cu)/IO4- system. The comparison with the photoactivated IO4- system, in which iodyl radical (IO3•) is a predominant oxidant in the presence of methanol, suggests IO3• also as primary oxidant in the nFe0-Ni(or Cu)/IO4- system.

The effect of granular ferric hydroxide amendment on the reduction of nitrate in groundwater by zero-valent iron.

The feasibility of using granular ferric hydroxide (GFH) with zero-valent iron (Fe(0)) for its potential utility in enhancing nitrate reduction was investigated. The addition of 10gL(-1) GFH to 25gL(-1) Fe(0) significantly enhanced nitrate removal, resulting in 93% removal of 52.2mg-NL(-1) in 36-h as compared to 23% removal with Fe(0) alone. Surface analyses of the reacted Fe(0)/GFH revealed the presence of magnetite on the Fe(0) surface, which probably served as an electron mediator for nitrate reduction. Addition of GFH to Fe(0) also resulted in lower solution pH compared to Fe(0). The rate enhancing effect of GFH on nitrate reduction was attributed to the combined effects of magnetite formation and pH buffering by GFH. GFH amendment (100gL(-1)) significantly increased reduction capacity and longevity of Fe(0) to complete several nitrate reduction cycles before inactivation, giving a total nitrate removal of 205mg-NL(-1), while unamended Fe(0) gave only 20mg-NL(-1) before inactivation during the first reduction cycle. The overall result demonstrated the potential utility of Fe(0)/GFH system that may be developed into a viable technology for removal of nitrate from groundwater.

Biodegradation of diphenyl ether and transformation of selected brominated congeners by Sphingomonas sp. PH-07.

Polybrominated diphenyl ethers (PBDEs) are common flame-retardant chemicals that are used in diverse commercial products such as textiles, circuit boards, and plastics. Because of the widespread production and improper disposal of materials that contain PBDEs, there has been an increasing accumulation of these compounds in the environment. The toxicity and bioavailability of PBDEs are variable for different congeners, with some congeners showing dioxin-like activities and estrogenicity. The diphenyl ether-utilizing bacterium Sphingomonas sp. PH-07 was enriched from activated sludge of a wastewater treatment plant. In liquid cultures, this strain mineralized 1 g of diphenyl ether per liter completely within 6 days. The metabolites detected and identified by gas chromatography/mass spectrometry (MS) and electrospray ionization/MS analysis corresponded with a feasible degradative pathway. However, the strain PH-07 even catabolized several brominated congeners such as mono-, di-, and tribrominated diphenyl ethers thereby producing the corresponding metabolites.