Proteomic profiling of L-cysteine induced selenite resistance in Enterobacter sp. YSU

Exploring the microbe-mediated biological processes of BTEX and toxic metal(loid)s in aging petrochemical landfills

Aging petrochemical landfills serve as reservoirs of inorganic and organic contaminants, posing potential risks of contamination to the surrounding environment. Identifying the pollution characteristics and elucidating the translocation/ transformation processes of typical contaminants in aging petrochemical landfills are crucial yet challenging endeavors. In this study, we employed a combination of chemical analysis and microbial metagenomic technologies to investigate the pollution characteristics of benzene, toluene, ethylbenzene, and xylene (BTEX) as well as metal(loid)s in a representative aging landfill, surrounding soils, and underlying groundwater. Furthermore, we aimed to explore their transformations driven by microbial activity. Our findings revealed widespread distribution of metal(loid)s, including Cd, Ni, Cu, As, Mn, Pb, and Zn, in these environmental media, surpassing soil background values and posing potential ecological risks. Additionally, microbial processes were observed to contribute significantly to the degradation of BTEX compounds and the transformation of metal(loid)s in landfills and surrounding soils, with identified microbial communities and functions playing key roles. Notably, co-occurrence network analysis unveiled the coexistence of functional genes associated with BTEX degradation and metal(loid) transformation, driven primarily by As, Ni, and Cd. These results shed light on the co-selection of resistance traits against BTEX and metal(loid) contaminants in soil microbial consortia under co-contamination scenarios, supporting microbial adaptive evolution in aging petrochemical landfills. The insights gained from this study enhance our understanding of characteristic pollutants and microbial transformation processes in aging landfills, thereby facilitating improved landfill management and contamination remediation strategies.

Biosynthesis of selenium nanoparticles and effects of selenite, selenate, and selenomethionine on cell growth and morphology in Rahnella aquatilis HX2

Rahnella aquatilis HX2 (proteobacteria) shows tolerance to selenium (Se). The minimum inhibitory concentrations of selenomethionine (Se-Met), selenite [Se (IV)], and selenate [Se (VI)] to HX2 are 4.0, 85.0, and 590.0 mM, respectively. HX2 shows the ability to reduce Se (IV) and Se (VI) to elemental Se nanoparticles (SeNPs). The maximum production of SeNPs by HX2 strain is 1.99 and 3.85 mM in Luria-Bertani (LB) broth with 5 mM Se (IV) and 10 mM Se (VI), respectively. The morphology of SeNPs and cells were observed by transmission electron microscope, environmental scanning electron microscope, and selected area electric diffraction detector. Spherical SeNPs with amorphous structure were found in the cytoplasm, membrane, and exterior of cells. Morphological variations of the cell membrane were further confirmed by the release of cellular materials absorbed at 260 nm. Flagella were inhibited and cell sizes were 1.8-, 1.6-, and 1.2-fold increases with the Se-Met, Se (VI), and Se (IV) treatments, respectively. The real-time quantitative PCR analysis indicated that some of the genes controlling Se metabolism or cell morphology, including cysA, cysP, rodA, ZntA, and ada, were significantly upregulated, while grxA, fliO, flgE, and fliC genes were significantly downregulated in those Se treatments. This study provided novel valuable information concerning the cell morphology along with biological synthesis process of SeNPs in R. aquatilis and demonstrated that the strain HX2 could be applied in both biosynthesis of SeNPs and in management of environmental Se pollution.

Robotic Total Gastrectomy With Intracorporeal Robot-Sewn Anastomosis: A Novel Approach Adopting the Double-Loop Reconstruction Method

Gastric cancer constitutes a major health problem. Robotic surgery has been progressively developed in this field. Although the feasibility of robotic procedures has been demonstrated, there are unresolved aspects being debated, including the reproducibility of intracorporeal in place of extracorporeal anastomosis.Difficulties of traditional laparoscopy have been described and there are well-known advantages of robotic systems, but few articles in literature describe a full robotic execution of the reconstructive phase while others do not give a thorough explanation how this phase was run.A new reconstructive approach, not yet described in literature, was recently adopted at our Center.Robotic total gastrectomy with D2 lymphadenectomy and a so-called "double-loop" reconstruction method with intracorporeal robot-sewn anastomosis (Parisi's technique) was performed in all reported cases.Preoperative, intraoperative, and postoperative data were collected and a technical note was documented.All tumors were located at the upper third of the stomach, and no conversions or intraoperative complications occurred. Histopathological analysis showed R0 resection obtained in all specimens. Hospital stay was regular in all patients and discharge was recommended starting from the 4th postoperative day. No major postoperative complications or reoperations occurred.Reconstruction of the digestive tract after total gastrectomy is one of the main areas of surgical research in the treatment of gastric cancer and in the field of minimally invasive surgery.The double-loop method is a valid simplification of the traditional technique of construction of the Roux-limb that could increase the feasibility and safety in performing a full hand-sewn intracorporeal reconstruction and it appears to fit the characteristics of the robotic system thus obtaining excellent postoperative clinical outcomes.

Anti-bacterial TeNPs biosynthesized by haloarcheaon Halococcus salifodinae BK3

Microbial synthesis of highly structured metal sulfide and metallic nanoparticles is a benign approach of nanomaterial synthesis. Various microbes have been exploited for nanoparticle synthesis, but nanofabrication using haloarchaea is still in nascent stages. Here, we report the intracellular synthesis of hexagonal needle-shaped tellurium nanoparticles with an aspect ratio of 1:4.4, by the haloarcheon Halococcus salifodinae BK3. The isolate was able to tolerate up to 5.5 mM K2TeO3. The yield of tellurium nanoparticles was highest when the culture was exposed to 3 mM K2TeO3, even though the isolate exhibited slightly decreased growth rate as compared to the culture growing in the absence of K2TeO3. The enzyme tellurite reductase was responsible for tellurite resistance and nanoparticle synthesis in H. salifodinae BK3. These tellurium nanoparticles exhibited anti-bacterial activities against both Gram-positive and Gram-negative bacteria, with higher antibacterial activity towards Gram-negative bacteria. This is the first report on the synthesis of tellurium nanoparticles by Halophilic archaea.