Isolation and characterization of bacteria associated with silkworm gut under antibiotic-treated larval feeding

The impact of antibiotics on growth, cocoon production was assessed in addition to isolation and characterization of bacteria associated with silkworm gut of infected larvae. Larval rearing was maintained at recommended conditions of temperature and humidity. Silkworm larvae showing abnormal symptoms were collected from the control group and dissected for gut collection. Bacteria were isolated from the gut content by spreading on agar plates and incubated at 37 °C for 48 hrs. Bacterial identification and phylogenetic analysis were carried out by 16S rRNA gene sequencing. The isolated bacteria were subjected to antimicrobial susceptibility test (disc diffusion methods) by using Penicillin (10 µg/mL), Tetracycline (30 µg/mL), Amoxicillin (25 µg/mL), Ampicillin (10 µg/mL), and Erythromycin (15 µg/mL). All isolated strains showed positive results for the catalase test. We isolated and identified bacterial strains (n = 06) from the gut of healthy and diseased silkworm larvae. Based on the 16S rRNA gene sequence, isolated bacteria showed close relation with Serratia, Bacillus, and Pseudomonas spp. Notably, 83.3% of strains were resistant to Penicillin, Tetracycline, Amoxicillin, Ampicillin, and Erythromycin but 16.6% showed antibiotic susceptibility to the above-mentioned commonly used antibiotics. Silkworm larvae fed on penicillin-treated leaves showed significant improvement in larval weight, larval length, and cocoon production. Significantly higher larval weight (6.88g), larval length (5.84cm), and cocoon weight (1.33g) were recorded for larvae fed on leaves treated with penicillin as compared to other antibiotics. Isolated bacterial strains showed close relation with Serratia spp., Bacillus spp. and Pseudomonas spp.

Isolation and characterization of bacteria residing in the oral, gut, and fecal samples of different pheasant species

There is a paucity of research conducted on microbial prevalence in pheasants. The microbiota of captive birds has zoonotic significance and must be characterize. Present study is therefore planned to assess the microbiota from oral, fecal and gut content of captive avian species. It will be helpful in characterization of harmful microbes. Different samples taken from oral, gut and feces of ring-necked pheasants (Phasianus colchicus), green pheasants (Phasianus versicolor), golden pheasant (Chrysolophus pictus) and silver pheasant (Lophura nycthemera). Samples were collected, diluted, and inoculated onto different agar plates (MacConkey, SS agar, MSA and nutrient agar) for cultivation of bacterial species. Colonies of E.coli, Staphylococcus spp. Brachyspira spp. and Campylobacter spp were observed based on colony morphology. Colony forming unit showed E. coli as frequently found bacteria in fecal, oral and gut contents of all the above pheasants. The overall significance difference was found among bacterial species of golden pheasants, green pheasant, ring-necked pheasant, and silver pheasants. It was concluded that E.coli is predominant isolated from heathy pheasants followed by Campylobacter, Staphylococcus and Brachyspira.

Revealing the Influence of Secondary Metals on Redox-Active Palladium Complexes

Incorporation of redox-inactive metals into redox-active complexes and catalysts attracts attention for engendering new reactivity modes, but this strategy has not been extensively investigated beyond the first-row of the transition metals. Here, the isolation and characterization of the first series of heterobimetallic complexes of palladium with mono-, di-, and tri-valent redox-inactive metal ions are reported. A Reinhoudt-type heteroditopic ligand with a salen-derived [N2,O2] binding site for Pd and a crown-ether-derived [O6] site has been used to prepare isolable adducts of the Lewis acidic redox-inactive metal ions (Mn+). Comprehensive data from single-crystal X-ray diffraction analysis reveal distinctive trends in the structural properties of the heterobimetallic species, including an uncommon dependence of the Pd•••M distance on Lewis acidity. The reorganization energy associated with reduction of the heterobimetallic species is strongly modulated by Lewis acidity, with the slowest heterogeneous electron transfer kinetics associated with the strongest incorporated Lewis acids. This hitherto unexplored reorganization energy penalty for electron transfer contrasts with prior thermodynamic studies, revealing that kinetic parameters should be considered in studies of reactivity involving heterobimetallic species.

In vitro anticancer and antibacterial potentials of selected medicinal plants and isolation and characterization of a natural compound from Withania coagulans

In the current study, five different plants, Syzygium Cumini, Fagonia cretica, Acacia modesta, Withania coagulans, and Olea europaea aqueous extracts were prepared and applied against the anticancer and antibacterial activities. It was observed that O. Europaea extract shows the highest anticancer activity with cell viability of 21.5%. All the five plants extract was also used against the inhibition of Bacillus subtilis where O. Europaea extract shows a promising inhibitory activity of 3.2 cm followed by W. coagulans. Furthermore, W. coagulans was subjected to the process of column chromatography as a result a withanolide was isolated. The fast atom bombardment mass spectrometry (FAB-MS) and high resolution fast atom bombardment (HRFAB-MS) [M + 1] indicated molecular weight at m/z 453 and molecular formula C28H37O5. The UV–Vis. spectrum shows absorbance at 210 nm suggesting the presence of conjugated system, and Fourier-transform infrared spectroscopy (FTIR) was recorded to explore the functional groups. Similarly, 1D and 2D NMR spectroscopy techniques such as 1H, 13C NMR, correlation spectroscopy (COSY-45°), heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC) and Nuclear Overhauser effect Spectroscopy (NOESY) techniques was carried out to determine the unknown natural product. The collective data of all these techniques established the structure of the unknown compound and recognized as a withanolide.

Isolation and Characterization of a Yellow Xanthophyll Pigment-Producing Marine Bacterium, Erythrobacter sp. SDW2 Strain, in Coastal Seawater

Xanthophylls, a yellow pigment belonging to the carotenoid family, have attracted much attention for industrial applications due to their versatile nature. We report the isolation of a homo xanthophyll pigment-producing marine bacterium, identified as the Erythrobacter sp. SDW2 strain, from coastal seawater. The isolated Erythrobacter sp. SDW2 strain can produce 263 ± 12.9 mg/L (89.7 ± 5.4 mg/g dry cell weight) of yellow xanthophyll pigment from 5 g/L of glucose. Moreover, the xanthophyll pigment produced by the SDW2 strain exhibits remarkable antioxidative activities, confirmed by the DPPH (73.4 ± 1.4%) and ABTS (84.9 ± 0.7%) assays. These results suggest that the yellow xanthophyll pigment-producing Erythrobacter sp. SDW2 strain could be a promising industrial microorganism for producing marine-derived bioactive compounds with potential for foods, cosmetics, and pharmaceuticals.

Isolation and Characterization of Primary Retinal Microglia From the Human Post-mortem Eyes for Future Studies of Ocular Diseases

Microglia, the primary resident immunocytes in the retina, continuously function as immune system supervisors in sustaining intraocular homeostasis. Microglia relate to many diseases, such as diabetic retinopathy, glaucoma, and optic nerve injury. To further investigate their morphology and functions in vitro, a reliable culture procedure of primary human retinal microglia is necessary. However, the culture condition of microglia from the adult retina is unclear. Researchers created several protocols, but most of them were carried out on rodents and newborns. This study describes a protocol to isolate and characterize human primary retinal microglia from human post-mortem eyes. The whole procedure started with removing the retinal vessels, mechanical separation and enzymatic dissociation, filtration, and centrifugation. Then, we cultured the cell suspensions on a T-75 flask for 18 days and then shook retinal microglia from other retinal cells. We found numerous retinal microglia grow and attach to Müller cells 10 days after seeding and increase rapidly on days 14–18. Iba1 and P2RY12 were used to qualify microglia through immunofluorescence. Moreover, CD11b and P2RY12 were positive in flow cytometry, which helps to discriminate microglia from other cells and macrophages. We also observed a robust response of retinal microglia in lipopolysaccharide (LPS) treatment with proinflammatory cytokines. In conclusion, this study provides an effective way to isolate and culture retinal microglia from adult human eyes, which may be critical for future functional investigations.

Automated light-induced synthesis of 89Zr-radiolabeled antibodies for immuno-positron emission tomography

Clinical production of 89Zr-radiolabeled antibodies (89Zr-mAbs) for positron emission tomography imaging relies on the pre-conjugation of desferrioxamine B (DFO) to the purified protein, followed by isolation and characterization of the functionalized intermediate, and then manual radiosynthesis. Although highly successful, this route exposes radiochemists to a potentially large radiation dose and entails several technological and economic hurdles that limit access of 89Zr-mAbs to just a specialist few Nuclear Medicine facilities worldwide. Here, we introduce a fully automated synthesis box that can produce individual doses of 89Zr-mAbs formulated in sterile solution in < 25 min starting from [89Zr(C2O4)4]4– (89Zr-oxalate), our good laboratory practice-compliant photoactivatable desferrioxamine-based chelate (DFO-PEG3-ArN3), and clinical-grade antibodies without the need for pre-purification of protein. The automated steps include neutralization of the 89Zr-oxalate stock, chelate radiolabeling, and light-induced protein conjugation, followed by 89Zr-mAb purification, formulation, and sterile filtration. As proof-of-principle, 89ZrDFO-PEG3-azepin-trastuzumab was synthesized directly from Herceptin in < 25 min with an overall decay-corrected radiochemical yield of 20.1 ± 2.4% (n = 3), a radiochemical purity > 99%, and chemical purity > 99%. The synthesis unit can also produce 89Zr-mAbs via the conventional radiolabeling routes from pre-functionalized DFO-mAbs that are currently used in the clinic. This automated method will improve access to state-of-the-art 89Zr-mAbs at the many Nuclear Medicine and research institutions that require automated devices for radiotracer production.