Ligand-mediated Changes in the Tryptophan Synthase Indole Tunnel Probed by Nile Red Fluorescence with Wild Type, Mutant, and Chemically Modified Enzymes

In the wake of global warming and rapid fossil fuel depletion, microalgae emerge as promising feedstocks for sustainable biofuel production. Nile red staining acts as a rapid diagnostic tool to measure the amount of biodiesel-convertible lipid that the cells accumulate. There is a need for the development of a more uniform staining procedure. In its first phase, this study examined the dependence of microalgal Nile red fluorescence (Tetraselmis suecica) in terms of its most pertinent staining variables. A quadratic surface model that successfully described the Nile red fluorescence intensity as a composite function of its variables was generated (r2=0.86). Cell concentration was shown to have a significant effect on the fluorescence intensity. Up to a certain threshold, fluorescence intensity was shown to increase with Nile red dye concentration. In its second phase, the study reviewed findings from previous Nile red studies to elucidate some of the fundamental mechanism underlying the diffusion of Nile red dye molecules into the microalgal cells and their subsequent interaction with intracellular lipids. Through the review process, we were able to develop a simple framework that provided a set of guidelines for the standardization of the Nile red staining procedure across different microalgal species.

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UV Mutagenesis as a Strategy to Enhance Growth and Lipid Productivity of Chlorella sp. 042

Journal of Tropical Biodiversity and Biotechnology ◽

10.22146/jtbb.56862 ◽

2020 ◽

Vol 5 (3) ◽

pp. 218

Author(s):

Rike Rachmayati ◽

Eva Agustriana ◽

Delicia Yunita Rahman

Keyword(s):

Nile Red ◽

Lipid Productivity ◽

Biodiesel Production ◽

Wild Type ◽

Uv Mutagenesis ◽

Chlorella Sp ◽

Uv Mutation ◽

High Lipid ◽

Nile Red Fluorescence ◽

Alternative Feedstock

Microalgae appeared to be an alternative feedstock for renewable biodiesel production due to their capability to accumulate considerable amounts of lipids. In this study, mutagenesis using UVC light with different periods was applied to Chlorella sp. 042 to produce a microalgae strain with high lipid productivity of 45, 60, and 75 min. The Nile red fluorescence method was conducted to select a Chlorella sp. mutant with high neutral lipid and generated one mutant from every UV mutation period, M45-06, M60-02, and M75-21. All of the mutants have higher growth rates than the wild type. Chlorella sp. 042 M60-02 achieved the highest lipid productivity, with 34 mg L-1 day-1. Furthermore, as other major biochemical components, carbohydrate and protein contents were determined. Our results showed that all the mutants enhance their carbohydrate and protein contents compared to the wild type. However, mutations for more than 60 min do not intensely change the protein content of mutant microalgae. Gas chromatography-mass spectrophotometry analysis revealed that M60-02 mutant has similar FAME profiles with the wild type, which contain palmitic acid (C16:0), stearic acid (C 18:0), oleic acid (C18:1), and linoleic acid (C18:2). These results demonstrate that the UV mutation of Chlorella sp. 042 for 60 min is suitable as a source of biodiesel production.

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Nile Red – contrasting colour cyanoacrylate

Issues of Forensic Science ◽

10.34836/pk.2015.290.7 ◽

2015 ◽

Vol 290 ◽

pp. 115-120

Author(s):

Ewa Rogoża ◽

◽

Katarzyna Drzewiecka ◽

Keyword(s):

Spectral Analysis ◽

Fluorescent Dyes ◽

Nile Red ◽

Laboratory Practice ◽

Excitation Light ◽

Red Fluorescence ◽

Yellow Orange ◽

Nile Red Fluorescence ◽

Filter Selection

Fingerprints disclosed by cyanoacrylate on non-absorbent substrates, in order to improve readabiIity, require additional contrasting fluorescent dyes. Nile Red is one of them. Its effectiveness was tested under conditions similar to those of daily laboratory practice. The highest Nile Red fluorescence occurred in an excitation light of blue-green and a wavelength of 505nm. Spectral analysis showed that the emission of light oscillates in the wavelength of about 630nm. In order to cut off the light, longpass edge filters of the colours yellow, orange or red can be used. Filter selection depends on the characteristics of the substrate and can be chosen empirically. Nile Red fluorescence does not change over a longer period of time, which allows for the registration of fingerprints to be performed within a time convenient for the testing, without fear of losing their quality. Nile Red may be an alternative to other fluorescent dyes used for visualization in fingerprint testing.

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