Identification of bacteria by poly-aromatic hydrocarbons biosensors

Human health is consistently threatened by different species of pathogenic bacteria. To fight the spread of diseases, it is important to develop rapid methods for bacterial identification. Over the years, different kinds of biosensors were developed for this cause. Another environmental risk are polyaromatic hydrocarbons (PAHs) that may be emitted from industrial facilities and pollute environmental water and soil. One of the methods for their purification is conducted by the addition of bacteria that can degrade the PAHs, while the bacteria itself can be filtrated at the end of the process. Although many studies reported monitoring of the PAHs degradation by fluorescence, not much attention was dedicated to studying the influence of the PAHs on the intrinsic fluorescence of the degrading bacteria. In this work, we apply synchronous fluorescence (SF) measurements to study the ability of the 5 PAHs: 9Antracene carboxylic acid (9ACA), Pyrene, Perylene, Pentacene, and Chrysene to interact with bacteria and change its fluorescence spectra. We show that upon incubation of each PAH with the bacterium E.coli only the 2 PAHs 9ACA and Perylene cause an intensity decrease in the emission at λ = 300 – 375 nm, which derives from the emission of Tyrosine and Tryptophane (TT). Also, we show that upon incubation of 9ACA and Perylene with 5 different pathogenic bacteria, the intensity increase or decrease in the TT emission is unique to each bacterial species. Based on this observation, we suggest that the PAHs 9ACA and Perylene can be utilized as biosensors for bacterial identification.

Nematic Mesogen with 1,3,4-Oxadiazole Unit as Stationary Phase in Gas-Liquid Chromatography

This paper is the first that deals with the new synthesis of nematic liquid crystal titled bis-[5-yl-phenylbenzidine-4`-butyloxyphenly-2-yl-1,3,4-oxadiazole] and secondly discusses research on materials that can be used in stationary phase by using (GLC) as a type of chromatography. The usage of bis-[5-yl-phenylbenzidine-4`-butyloxyphenly-2-yl-1,3,4-oxadiazole]nematic phase has resulted in a lot of superb separations of a lot of poly aromatic hydrocarbons. The retention time change in an unusual way with temperature, appearance a significant increase at the normal liquid transmission point; as expected, that impact is reduced with further planar compounds. FT-IR and 1HNMR were used to characterize the synthesized chemical structure, and POM and DSC were used to investigate the liquid crystalline characteristics.

Evaluation of Asa River Water in Ilorin, Kwara State, Nigeria for Available Pollutants and their Effects on Mitosis and Chromosomes Morphology in Allium cepa Cells

T: This study evaluated water samples from Asa River in Kwara state, Nigeria, for cytogenotoxicity at 25.0 %, 50.0 %, 100.0 % following the Allium cepa assay. Onions were grown in the water samples for microscopic and macroscopic screenings. Heavy metals and volatile organic pollutants in the water were elucidated using AAS and GCMS techniques. The Water samples except the sample ‘C’ induced higher mitotic index (MI) than the negative control. Root growth was significantly promoted at 25.0 %, and significantly reduced at 50.0 % and 100.0 % of the sample ‘C’ and 100.0 % of the sample ‘A’. Water sample ‘A’ (100.0%) induced highest percentage chromosomal aberrations (CA) while the water samples ‘B’ and ‘C’ induced higher percentage CA than the negative control. Cadmium was detected at a concentration higher than its permissible limit in drinking water. Poly aromatic hydrocarbons, Aromatic amines, Acridine dye, Phenolic and Polychlorinated compounds were detected in the water sample. The observed proliferative, inhibitory, cytotoxic and genotoxic effects of the water samples on A. cepa cells suggest that Asa river was polluted, having potential to adversely affect humans, animals and plants utilizing it along its course. Keywords: Allium cepa; Asa River; cytogenotoxicity; Nigeria; pollutants

Screening of Asa River water in Ilorin, Kwara State, Nigeria for available pollutants and its effects on mitosis and chromosomes morphology in Allium cepa cells

Improper disposal of wastes as an environmental problem is common in African and other developing countries of the world, and it raises concerns due to its potential threats to the life of organisms in both terrestrial and aquatic ecosystems. In this study, Asa River in Ilorin, Nigeria was evaluated for cytogenotoxicity at 25.0 %, 50.0 %, 100.0 % following the Allium cepa assay. Water samples were collected from three points tagged A, B, C, and each point was 500 m apart from each other. The water samples were used to grow A . cepa for microscopic and macroscopic toxicities screenings. Heavy metals and volatile organic pollutants in the water were elucidated following the Atomic Absorption Spectroscopy and Gas Chromatography-Mass Spectroscopy. The Water samples induced higher mitotic index values, except the sample C which induced smaller mitotic index value than the negative control. Root growth in the exposed A . cepa was significantly promoted at 25.0 % of the water samples, while significant reduction was obtained at 50.0 % and 100.0 % of the sample C, and 100.0 % of the sample A. The absolute water sample A induced highest percentage chromosomal aberrations, as the water samples B and C induced higher percentage chromosomal aberration than the negative control. Cadmium was detected at a concentration higher than its permissible limit in drinking water unlike Zinc, Iron, Manganase. Poly aromatic hydrocarbons, Aromatic amines, Acridine dye, Phenolic and Polychlorinated compounds were detected in the water sample. These pollutants may be responsible for the observed proliferative, inhibitory, cytotoxic and genotoxic effects of the water samples on A . cepa cells. Our results suggest that Asa River is polluted, having potential to inflict different adverse effects on human, animals and plants utilizing it along its course.