Overcoming challenges due to enhanced biomedical waste generation during COVID-19 pandemic.

Biomedical wastes (BMWs) are potentially infectious to the environment and health. They are co-dependent and accumulative during the ongoing coronavirus disease-2019(COVID-19) pandemic. In India the standard treatment processes of BMWs are incineration, autoclaving, shredding, and deep burial; however, incineration and autoclaving are the leading techniques applied by many treatment providers. These conventional treatment methods have several drawbacks in terms of energy, cost, and emission. But the actual problem for the treatment providers is the huge and non-uniform flow of the BMWs during the pandemic. The existing treatment methods are lacking flexibility for the non-uniform flow. The Government of India has provisionally approved some new techniques like plasma pyrolysis, sharp/needle blaster, and PIWS-3000 technologies on a trial basis. But they are all found to be inadequate in the pandemic. Therefore, there is an absolute requirement to micromanage the BMWs based on certain parameters for the possible COVID-19 like pandemic in the future. Segregation is a major step of the BMW management. Its guideline may be shuffled as segregation at the entry points followed by collection instead of the existing system of the collection followed by segregation. Other steps like transportation, location of treatment facilities, upgradation of the existing treatment facilities, and new technologies can solve the challenges up to a certain extent. Technologies like microwave treatment, alkaline hydrolysis, steam sterilization, biological treatment, catalytic solar disinfection, and nanotechnology have a lot of scopes for the treatment of BMWs. Hi-tech approaches in handling and transportation are found to be fruitful in the initial steps of BMW management. End products of the treated BMWs can be potentially fabricated for the application in the built environment. Some policies need to be re-evaluated by the health care facilities or government administrations for efficient BMW management.

Evaluation of molybdenum recovery from sulfur removed spent catalyst using leaching and solvent extraction.

In this article a new spent catalyst sample preparation method was implemented for the purpose of molybdenum leaching in a single step. Further molybdenum and vanadium in the leach liquor were separated and their concentrations were enriched using the solvent extraction and stripping techniques. The impervious sulfur (S0) layer of the spent catalyst sample was removed using carbon disulfide (CS2). The advantages of S0removal were evaluated by conducting different sets of the Mo leaching experiments and they were further examined by varying different conditions such as three lixiviants, hydrogen peroxide (H2O2) addition, and three leaching parameters. The leaching rate increased in an order, e.g. acetone washed < acetone-CS2 washed < acetone washed-H2O2 < acetone-CS2 washed-H2O2, for the experimental concentration range of different lixiviants with the maximum of 94.8%(w/w) Mo dissolution in a single step. Optimization of the pulp density was important as the interaction of lixiviant molecules with multiple reacting solid particles decreased the driving force of the chemical reactions. The solvent extraction followed by the stripping technique was found to be excellent as the concentration of vanadium and molybdenum enriched from 0.55 to 1.9 M and 0.0448 to 1.08 M, respectively.

Geochemical Cycle of Radon and its Bioremediation Opportunity from Water Environment: A Review.

BACKGROUND: The waterborne or airborne radon causes carcinogenesis in the human bodies due to the continuous decay of α- and ß- particles. The health risks related to radioactive radon instigate to develop an advanced technology for its removal from the environment. There are two standard techniques, such as aeration and activated carbon filtration, available for its removal. However, both of them face different technological drawbacks resulting in the processes either inefficient or inappropriate for the purpose. CONCLUSION: There are several technologies utilizing either algae or microorganisms that could be useful in the bioremediation of radon. Some of the algae and microorganisms are examined and found to be tolerated and decontaminated various ionization radiations like α-, ß-, and γ- radiations. In a US patent, the microalgae Coccomyxa actinabiotis isolated from a nuclear facility showed the properties of bioremediation towards radionuclides. They overcome the physiological stress in the extreme environment for their growth due to the evolution under the prolonged influence of high energy radiation. Further, they are stimulated by the process of cloning, genetic transformations and adaptations for the purpose of enhancing the tolerance and decontamination power. Therefore, biotechnological researches have lots of prospects to remove radon from the water environment using algae and microorganisms.

Statistical optimization for lipase production from solid waste of vegetable oil industry.

The production of biofuel using thermostable bacterial lipase from hot spring bacteria out of low-cost agricultural residue olive oil cake is reported in the present paper. Using a lipase enzyme from Bacillus licheniformis, a 66.5% yield of methyl esters was obtained. Optimum parameters were determined, with maximum production of lipase at a pH of 8.2, temperature 50.8°C, moisture content of 55.7%, and biosurfactant content of 1.693 mg. The contour plots and 3D surface responses depict the significant interaction of pH and moisture content with biosurfactant during lipase production. Chromatographic analysis of the lipase transesterification product was methyl esters, from kitchen waste oil under optimized conditions, generated methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate.

Bioprospecting hot spring metagenome: lipase for the production of biodiesel.

Screening of metagenomic library from Taptapani Hot Spring (Odisha) yielded a positive lipase clone (pUC-lip479). Sequence analysis showed an ORF (RK-lip479) of 416 amino acid residues which was overexpressed in Escherichia coli BL21 (DE3). Optimum pH and temperature of purified lipase RK-lip479 were 8.0 and 65 °C, respectively, and found to be stable over a pH range of 7.0-9.0 and temperatures 55-75 °C. RK-lip479 could hydrolyse a wide range of 4-nitrophenyl esters (4-nitrophenyoctanoate, 4-nitrophenyldodecanoate, 4-nitrophenylpalmitate, 4-nitrophenylmyristate and 4-nitrophenylstearate), and maximum activity was observed with 4-nitrophenyldodecanoate. RK-lip479 was resistant to many organic solvents, especially isopropanol, DMSO, methanol, DMF, ethanol, dichloromethane, acetone, glycerol and ethyl acetate. RK-lip479 also showed activity in the presence of monovalent (Na+ and K+), divalent (Mg2+, Mn2+, Ca2+, Hg2+, Cu2+, Co2+, Zn2+ and Ag2+ ) and trivalent cations (Fe3+ and Al3+). Yield of biodiesel production was in the range of 40-76% using various waste oils with RK-Lip479 under optimized conditions.

Microalga Scenedesmus sp.: A potential low-cost green machine for silver nanoparticle synthesis.

Bionanotechnology has revolutionized nanomaterial synthesis by providing a green synthetic platform using biological systems. Among such biological systems, microalgae have tremendous potential to take up metal ions and produce nanoparticles by a detoxification process. The present study explores the intracellular and extracellular biogenic syntheses of silver nanoparticles (SNPs) using the unicellular green microalga Scenedesmus sp. Biosynthesized SNPs were characterized by AAS, UV-Vis spectroscopy, TEM, XRD, FTIR, DLS, and TGA studies and finally checked for antibacterial activity. Intracellular nanoparticle biosynthesis was initiated by a high rate of Ag(+) ion accumulation in the microalgal biomass and subsequent formation of spherical crystalline SNPs (average size, 15-20 nm) due to the biochemical reduction of Ag(+) ions. The synthesized nanoparticles were intracellular, as confirmed by the UV-Vis spectra of the outside medium. Furthermore, extracellular synthesis using boiled extract showed the formation of well scattered, highly stable, spherical SNPs with an average size of 5-10 nm. The size and morphology of the nanoparticles were confirmed by TEM. The crystalline nature of the SNPs was evident from the diffraction peaks of XRD and bright circular ring pattern of SAED. FTIR and UV-Vis spectra showed that biomolecules, proteins and peptides, are mainly responsible for the formation and stabilization of SNPs. Furthermore, the synthesized nanoparticles exhibited high antimicrobial activity against pathogenic gram-negative and gram-positive bacteria. Use of such a microalgal system provides a simple, cost-effective alternative template for the biosynthesis of nanomaterials in a large-scale system that could be of great use in biomedical applications.

Application of lipopeptide biosurfactant isolated from a halophile: Bacillus tequilensis CH for inhibition of biofilm.

Biosurfactants are amphiphilic molecules having hydrophobic and hydrophilic moieties produced by various microorganisms. These molecules trigger the reduction of surface tension or interfacial tension in liquids. A biosurfactant-producing halophile was isolated from Lake Chilika, a brackish water lake of Odisha, India (19°41'39″N, 85°18'24″E). The halophile was identified as Bacillus tequilensis CH by biochemical tests and 16S rRNA gene sequencing and assigned accession no. KC851857 by GenBank. The biosurfactant produced by B. tequilensis CH was partially characterized as a lipopeptide using thin-layer chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance techniques. The minimum effective concentration of a biosurfactant for inhibition of pathogenic biofilm (Escherichia coli and Streptococcus mutans) on hydrophilic and hydrophobic surfaces was found to be 50 µg ml(-1). This finding has potential for a variety of applications.

Extraction and characterization of biocompatible hydroxyapatite from fresh water fish scales for tissue engineering scaffold.

In bone tissue engineering, porous hydroxyapatite (HAp) is used as filling material for bone defects, augmentation, artificial bone graft and scaffold material. The present paper compares the preparation and characterization of HAp from fish scale (FS) and synthetic body fluid (SBF) solution. Thermo gravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and particle size analysis of the samples have been performed. The analysis indicates that synthesized HAp consists of sub-micron HAp particle with Ca/P ratio corresponding to FS and SBF 1.62 and 1.71, respectively. MTT assay and quantitative DNA analysis show growth and proliferation of cells over the HA scaffold with the increase in time. The shape and size (morphology) of mesenchymal stem cells after 3 days show a transition from rounded shape to elongated and flattened shape expressing its spreading behavior. These results confirm that HAp bio-materials from fish scale are physico-chemically and biologically equivalent to the chemically synthesized HAp from SBF. Biological HAp, thus, possesses a great potential for conversion of industrial by-product into highly valuable compounds using simple effective and novel processes.

Inhibition of pathogenic bacterial biofilm by biosurfactant produced by Lysinibacillus fusiformis S9.

A biosurfactant producing microbe isolated from a river bank was identified as Lysinibacillus fusiformis S9. It was identified with help of biochemical tests and 16S rRNA gene phylogenetic analysis. The biosurfactant S9BS produced was purified and characterized as glycolipid. The biosurfactant showed remarkable inhibition of biofilm formation by pathogenic bacteria like Escherichia coli and Streptococcus mutans. It was interesting to note that at concentration of 40 µg ml(-1) the biosurfactant did not show any bactericidal activity but restricted the biofilm formation completely. L. fusiformis is reported for the first time to produce a glycolipid type of biosurfactant capable of inhibiting biofilm formation by pathogenic bacteria. The biosurfactant inhibited bacterial attachment and biofilm formation equally well on hydrophilic as well as hydrophobic surfaces like glass and catheter tubing. This property is significant in many biomedical applications where the molecule should help in preventing biofouling of surfaces without being toxic to biotic system.

Extraction of Copper from Malanjkhand Low-Grade Ore by Bacillus stearothermophilus.

Thermophilic bacteria are actively prevalent in hot water springs. Their potential to grow and sustain at higher temperatures makes them exceptional compare to other microorganism. The present study was initiated to isolate, identify and determine the feasibility of extraction of copper using thermophilic heterotrophic bacterial strain. Bacillus stearothermophilus is a thermophilic heterotrophic bacterium isolated from hot water spring, Atri, Orissa, India. This bacterium was adapted to low-grade chalcopyrite ore and its efficiency to solubilize copper from Malanjkhand low-grade ore was determined. The low-grade copper ore contains 0.27% Cu, in which the major copper-bearing mineral is chalcopyrite associated with other minerals present as minor phase. Variation in parameters such as pulp-density and temperatures were studied. After 30 days of incubation, it was found that Bacillus stearothermophilus solubilize copper up to 81.25% at pH 6.8 at 60°C.