Synergy between microalgae and microbiome in polluted waters.

Microalga-microbiome interactions are central to both health and disease of aquatic environments. Despite impressive advances in deciphering how microorganisms participate in and impact aquatic ecosystems, the evolution and ecological involvement of microalgae and the microbiome in polluted waters are typically studied independently. Here, the phycosphere (i.e., the consortia of microalgae and the related microbiome) is regarded as an independent and integrated life form, and we summarize the survival strategies exhibited by this symbiont when exposed to anthropogenic pollution. We highlight the cellular strategies and discuss the modulation at the transcriptional and population levels, which reciprocally alters community structure or genome composition for medium-term acclimation or long-term adaptation. We propose a 'PollutantBiome' concept to help the understanding of microalga-microbiome interactions and development of beneficial microbial synthetic communities for pollutant remediation.

Optimization for silver remediation from aqueous solution by novel bacterial isolates using response surface methodology: Recovery and characterization of biogenic AgNPs.

Silver is a toxic but precious heavy metal that has been implemented in diverse biomedical and environmental sectors. Extensive use of this metal has provoked severe environmental concerns. Hence there is an increasing demand for the development of a simple, inexpensive and eco-friendly approach for the remediation and recovery of silver. In this study, novel bacterial strains Enterobacter cloacae SMP1, Cupriavidus necator SMP2, and Bacillus megaterium SMP3 were isolated from silver mining site for the sake of silver remediation. Various experimental factors including temperature, pH and inoculum size (I_S) were optimized for silver remediation by SMP1 using central composite design (CCD) based on response surface methodology (RSM). For maximum 100% removal of silver the optimized values of temperature, pH and I_S were 23.5 °C, 7.5 and 2% (v/v) respectively in less than 10 h of incubation. Simultaneously, silver nanoparticles (AgNPs) were harvested through centrifugation (M1) and by applying voltage (M2) to the crude remediation mixture. The AgNPs, characterized by UV-vis spectroscopy, dynamic light scattering (DLS), and cryo-scanning transmission electron microscopy (Cryo-SETM), were spherical shaped and 1.75-8.7 nm in diameter. The average zeta potentials (ZP) of AgNPs isolated by M1, and M2 were -35.8 mV and -45.2 mV respectively.

Enhanced remediation of bispyribac sodium by wheat (Triticum aestivum) and a bispyribac sodium degrading bacterial consortium (BDAM).

The use of plant-bacterial association is a promising approach for the enhanced remediation of pesticides. Generally, both rhizo- and endosphere bacteria assist their host plants to survive in the contaminated environment. In this work, we have studied the individual and combined effects of wheat (Triticum aestivum) and a previously optimized bispyribac sodium (BS) degrading bacterial consortium (BDAM) on the degradation of BS and plant biomass production. Results showed that the bacterial strains of the BDAM have successfully survived in the plant rhizo-as well as endosphere and enhanced degradation of BS and plant biomass. In soil spiked with 2 mg/kg and 5 mg/kg of BS and was planted and inoculated with BDAM (P_I) showed 100% degradation of BS both in rhizosphere soil and endosphere of the plant. However, during the same period (45 days) the degradation of BS was 96 and 90%, and 93 and 84% in inoculated but un-planted (I_UP) and planted but un-inoculated (P_UI) soils spiked with 2 and 5 mg/kg, respectively. Liquid chromatography-mass spectrometry (LC-MS) analysis of the treated samples showed novel degradation products of BS. Based on the results, we concluded that plant-bacterial association is an efficient tool for enhanced remediation of BS contaminated soil and herbicide free crop production.

Application of a novel bacterial consortium BDAM for bioremediation of bispyribac sodium in wheat vegetated soil.

Plant-bacterial mutualism has tremendous potential for remediation of herbicide contaminated soils. Generally, bacterial inoculation helps plants to grow well in the contaminated environment. Here, we investigated the impact of bispyribac sodium (BS) degrading bacterial consortium (BDAM) on BS remediation, plant growth promotion and BS accumulation in plant parts. Wheat (Triticum aestivum) was planted in BS spiked soil and inoculated with BDAM. Inoculation showed a beneficial effect on plant biomass production and degradation of BS in the rhizosphere and the rhizosheath. After 40 and 60 days of inoculation, the degradation of BS was more than 96% and approximately 100% respectively in the planted and inoculated soil spiked with 2 and 5 mg kg-1 BS. However, in planted and un-inoculated soil, the degradation of BS was 72% after 60 days of sowing. Furthermore, inoculated bacterial strains colonized both in rhizo- and endosphere of the inoculated plants. In comparison with the un-inoculated soil, significantly less accumulation of BS was found in the roots and shoots of the plants growing in inoculated soil. We report the efficiency of plant-bacterial partnership for enhanced biodegradation of BS and to eliminate the BS residual toxicity to non-target plants.

Iron/iron oxide nanoparticles: advances in microbial fabrication, mechanism study, biomedical, and environmental applications.

Microbially synthesized iron oxide nanoparticles (FeONPs) hold great potential for biomedical, clinical, and environmental applications owing to their several unique features. Biomineralization, a process that exists in almost every living organism playing a significant role in the fabrication of FeONPs through the involvement of 5-100 nm sized protein compartments such as dodecameric (Dps), ferritin, and encapsulin with their diameters 9, 12, and ∼32 nm, respectively. This contribution provides a detailed overview of the green synthesis of FeONPs by microbes and their applications in biomedical and environmental fields. The first part describes our understanding in the biological fabrication of zero-valent FeONPs with special emphasis on ferroxidase (FO) mediated series of steps involving in the translocation, oxidation, nucleation, and storage of iron in Dps, ferritin, and encapsulin protein nano-compartments. Secondly, this review elaborates the significance of biologically synthesized FeONPs in biomedical science for the detection, treatment, and prevention of various diseases. Thirdly, we tried to provide the recent advances of using FeONPs in the environmental process, e.g. detection, degradation, remediation and treatment of toxic pesticides, dyes, metals, and wastewater.

Biological synthesis of metallic nanoparticles (MNPs) by plants and microbes: their cellular uptake, biocompatibility, and biomedical applications.

Metallic nanoparticles (MNPs) with their diverse physical and chemical properties have been applied in various biomedical domains. The increasing demand for MNPs has attracted researchers to develop straightforward, inexpensive, simple, and eco-friendly processes for the enhanced production of MNPs. To discover new biomedical applications first requires knowledge of the interactions of MNPs with target cells. This review focuses on plant and microbial synthesis of biological MNPs, their cellular uptake, biocompatibility, any biological consequences such as cytotoxicity, and biomedical applications. We highlighted the involvement of biomolecules in capping and stabilization of MNPs and the effect of physicochemical parameters particularly the pH on the synthesis of MNPs. Recently achieved milestones to understand the role of synthetic biology (SynBiol) in the synthesis of tailored MNPs are also discussed.

Comparison of Clinical Outcome of Facial Artery Myomucosal Flap and Tongue Flap for Closure of Large Anterior Palatal Fistulas.

Closure of large anterior palatal fistula has high recurrence rate. The objective of this study was to compare the clinical outcome of facial artery myomucosal flap (FAMM flap) and tongue flap used for closure of large anterior palatal fistula. This study was conducted from March 2008 to March 2014. Thirty-nine patients, aged 2 to 40 years, who had anterior palatal fistula 5 to 20 mm in width with associated alveolar cleft and repaired with either a tongue flap or FAMM flap were included. Patients were excluded if they had adequate local palatal tissue for closure, mid, posterior or multiple fistulae, fistula width >20 mm. Closure was performed in 2 layers. Turndown flap of oral mucoperiosteum was used to reconstruct nasal layer and oral layer was reconstructed with FAMM flap in 16 and tongue flap in 23 patients. Mean(SD) pain score was 3(1) and 7(1) in FAMM flap and tongue flap groups respectively with a P value <0.096. All patients in tongue flap group experienced difficulty in speaking and eating whereas in FAMM flap group 2 had eating problem and 2 experienced speech difficulty. Mean(SD) total operative times for FAMM flap and tongue flap were 155(38) and 242(10) minutes, respectively, P value <0.002. There was no difference for other complications and no recurrence at 1 year follow-up in both groups. The authors concluded that FAMM flap should be considered first choice for closure of large anterior palatal fistulas associated with alveolar cleft as it requires less total operative time and has less early postoperative complications.