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Biomimetic Designed Surfaces for Growth Suppression of Biofilm-Inspired Sharkskin Denticles
Published in Akihiro Miyauchi, Masatsugu Shimomura, Biomimetics, 2023
Mariko Miyazaki, Akihiro Miyauchi
To quantify the bacteria covering rate of the test samples, the samples taken out after culturing for five days were gram stained and observed with an optical microscope. Gram staining is a method for dyeing bacteria with pigments [37]. In this study, crystal violet was used as a staining solution. The test samples were immersed in a crystal violet solution for one minute and then stained by rinsing them with purified water. The covering rate of the bacteria was quantified by processing the optical microscope images obtained after dyeing. If more bacteria are attached to the test samples, more stains are observed, and the image appears darker. To quantify the covering ratio of bacteria, each pixel of the image was binarized in which black and white pixels represent areas where bacteria is and is not adhered, respectively and the covering of the bacteria is defined the following formula. Covering ratio of bacteria = Area of black area Total area of image ×100(%)
Microbiological drinking water parameters
Published in Frank R. Spellman, The Drinking Water Handbook, 2017
The Gram staining procedure was developed in the 1880s by Hans Christian Gram, a Danish bacteriologist. Gram discovered that microbes could be distinguished from surrounding tissue and observed that some bacterial cells exhibit an unusual resistance to decolorization. He used this observation as the basis for a differential staining technique. Gram differentiation is based on the application of a series of four chemical reagents: primary stain, mordant, decolorizer, and counterstain. The purpose of the primary stain, crystal violet, is to impart a blue or purple color to all organisms regardless of their Gram reaction. This is followed by the application of Gram’s iodine, which acts as a mordant (fixer) that enhances the union between the crystal violet stain and its substrate by forming a complex. The decolorizing solution of 95% ethanol extracts the complex from certain cells more readily than others. In the final step, a counterstain (safranin) is applied to reveal organisms previously decolorized by removal of the complex. Those organisms retaining the complex are Gram positive (blue or purple), whereas those losing the complex are Gram negative (red or pink).
Electrospinning of Nanofibers
Published in Yubing Xie, The Nanobiotechnology Handbook, 2012
Laccase is a copper-containing oxidase that is capable of catalyzing one-electron oxidation of various compounds (Lettera et al. 2010). These compounds include phenols, chlorinated phenols, aromatic substrates, pesticides, endocrine disrupters, and various dyes, to name a few (Dai et al. 2010, Majeau et al. 2010). One important application of laccase is biodegradation and biotransformation of pollutants, such as for wastewater treatment (Auriol et al. 2008, Garcia et al. 2011). The issue with using this enzyme in free form is that it loses its activity quickly in aqueous solutions (Shin-ya et al. 2005). Thus, there is a need for immobilizing laccase in order to increase its stability. Core-shell electrospinning has also been used to incorporate laccase into poly(n,l-lactide) (PDLLA)/PEO-PPO-PEO (F108) electrospun microfibers (Dai et al. 2010). PEO-PPO-PEO (F108) is a triblock copolymer that can be purchased in this form. In this case, the laccase and polymer solution were made into an emulsion prior to electrospinning so that laccase could be immobilized in situ. Dai et al. decided to observe how this construct affected the degradation of a crystal violet dye, which can bind to DNA. This degradation can be toxic to human health by causing moderate eye irritation, permanent injury to the cornea and conjunctiva, and, if exposed long term, cancer (Crystal Violet MSDS 2011). Crystal violet is a synthetic dye that is used in the textile, paper, printing, cosmetics, and pharmaceutical industries (Dai et al. 2010). Thus, exposure is quite common. The activity of immobilized laccase was found to be about 67% of that of free laccase, which is considerable since the enzyme was immobilized and encapsulated.
Adsorptive removal of hazardous crystal violet dye onto banana peel powder: equilibrium, kinetic and thermodynamic studies
Published in Journal of Dispersion Science and Technology, 2022
Muhammad Azhar-ul-Haq, Tariq Javed, Muhammad Amin Abid, Hafiz Tariq Masood, Nafeesa Muslim
Crystal violet is a member of the basic/cationic class of dyes. It is also named as gentian violet or methyl violet. It is a cationic triarylmethane dye having molecular formula C25H30N3Cl and molar weight 407.979 Structural formulae of crystal violet dye is shown in Figure 1. Crystal violet dye is applied in a number of industries such as textile dyeing, biological staining, printing and manufacturing of paint. Crystal violet also finds its applications as an antiseptic, an antimicrobial agent and a disinfectant. It is non-biodegradable and possesses carcinogenic effects. Continuous contact to CV can lead to eye and skin irritation, respiratory allergy, cornea injury and kidney failures.[6,7] It may cause coughing, dizziness, chest tightness, disorientation, vertigo and mild skin irritation. It may also trigger off systemic injury with harmful consequences if it enters into the blood through cuts, scratches or wounds.[8] Hence removal of crystal violet from wastewater is very crucial.
A novel, eco-friendly bio-nanocomposite (Alg-Cst/Kal) for the adsorptive removal of crystal violet dye from its aqueous solutions
Published in International Journal of Phytoremediation, 2021
Jyoti Mittal, Rais Ahmad, Mohammad Osama Ejaz, Asna Mariyam, Alok Mittal
The intense urbanization and industrialization have accentuated environmental pollution problems and lead to degrading the water quality day by day. We are deteriorating our natural water resources as if there is no tomorrow (Goel 2006). Hence, improving the quality of water to make it usable for the society is a critical issue and seriously addressed by the researchers (Goel 2006; Laws 2018). Amongst various chemicals polluting the water, dyes are the most complex and easily detectable toxic substances. Dyes are usually discharged from various common industries like paper, pulp, dyeing, textiles, plastics, leather, cosmetics, food etc. The emission from these manufacturing/processing units as effluent is major cause for their abundant availability in wastewater. Dyes are stable and non-biodegradable due to their complex bulky aromatic structures (Reife and Freeman 1996). They are toxic, carcinogenic and may cause acute chronic effects on humans and other living beings (Reife and Freeman 1996; Lellis et al.2019) . Crystal Violet (CV) is a cationic triarylmethane dye, which is potentially toxic, mutagenic and carcinogenic (Thomas and MacPhee 1984). It imparts various eye-related problems like irritation, conjunctiva and cornea injury. On prolonged exposure, it can cause respiratory ailment, kidney failure, permanent blindness and cancer (Jones et al.2003). This dye is a potential biohazard due to its mitotic poisoning property (Saji et al.1995). Therefore, the removal of the CV from water is highly desirable.
Paddle cactus (Tacinga palmadora) as potential low-cost adsorbent to treat textile effluents containing crystal violet
Published in Chemical Engineering Communications, 2020
Jordana Georgin, Dison S. P. Franco, Fernanda C. Drumm, Patrícia Grassi, Matias Schadeck Netto, Daniel Allasia, Guilherme L. Dotto
The textile, paper, leather, cosmetics, and printing sectors are well known concerning the use and discharge of organic compounds like dyes in the environment. The presence of dyes into water bodies generates several problems, such as undesirable color and reduction of sunlight penetration (Machado et al., 2012). The crystal violet (CV) dye is normally used by the textile and paper industries, and also in biological stain (Zhang et al., 2014). Removal of this dye from nature is important because it is harmful to human health, and may favor the appearance of cancer cells in the body. Because it fits into the class of triarylmethane dyes, its chemical structure is highly diversified and complex, making it a dye of great durability and of difficult degradation in the environment (Haik et al., 2010).