Removal of synthetic dyes from wastewaters: a review.

A variety of synthetic dyestuffs released by the textile industry pose a threat to environmental safety. Azo dyes account for the majority of all dyestuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics and pharmaceutical industries. Existing effluent treatment procedures are unable to remove recalcitrant azo dyes completely from effluents because of their color fastness, stability and resistance to degradation. Bacterial decolorization and degradation of azo dyes under certain environmental conditions has gained momentum as a method of treatment, as these are inexpensive, eco-friendly and can be applied to wide range of such dyes. This review mainly focuses on the different mechanisms of decolorization and discusses the effect of various physicochemical parameters on the dye removal efficiency of different bacteria. The enzymatic mechanisms involved in the bacterial degradation of azo dyes, the identification of metabolites by using various analytical techniques, and the nature of their toxicity has been investigated. This review provides an overview of bacterial decolorization/degradation of azo dyes and emphasizes the application of these processes for the treatment of azo dye-containing wastewaters.

Bacterial decolorization and degradation of azo dyes: a review.

Bacterial Decolorization and Degradation of Azo Dyes

https://link.springer.com/content/pdf/10.1007%2Fs10156-009-0669-9.pdf

Loop-mediated isothermal amplification (LAMP): a rapid, accurate, and cost-effective diagnostic method for infectious diseases

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EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on Scientific Opinion on risk based control of biogenic amine formation in fermented foods

Molecular cloning and characterization of the gene coding for azoreductase from Bacillus sp. OY1-2 isolated from soil.

Histamine fish poisoning is caused by histamine-producing bacteria (HPB). Klebsiella pneumoniae and Klebsiella oxytoca are the best-known HPB in fish. However, 22 strains of HPB from fish first identified as K. pneumoniae or K. oxytoca by commercialized systems were later correctly identified as Raoultella planticola (formerly Klebsiella planticola) by additional tests. Similarly, five strains of Raoultella ornithinolytica (formerly Klebsiella ornithinolytica) were isolated from fish as new HPB. R. planticola and R. ornithinolytica strains were equal in their histamine-producing capabilities and were determined to possess the hdc genes, encoding histidine decarboxylase. On the other hand, a collection of 61 strains of K. pneumoniae and 18 strains of K. oxytoca produced no histamine.

Klebsiella pneumoniae produces no histamine: Raoultella planticola and Raoultella ornithinolytica strains are histamine producers.

A number of nucleic acid amplification assays (NAAs) have been employed to detect tubercle bacilli in clinical specimens for tuberculosis (TB) diagnosis. Among these, loop-mediated isothermal amplification (LAMP) is an NAA possessing superior isothermal reaction characteristics. In the present study, a set of six specific primers targeting the Mycobacterium tuberculosis 16S rRNA gene with high sensitivity was selected and a LAMP system (MTB-LAMP) was developed. Using this system, a total of 200 sputum samples from Nepalese patients were investigated. The sensitivity of MTB-LAMP in culture-positive samples was 100 % (96/96), and the specificity in culture-negative samples was 94.2 % (98/104, 95 % confidence interval 90.5-97.9 %). The positive and negative predictive values of MTB-LAMP were 94.1 and 100 %, respectively. These results indicate that this MTB-LAMP method may prove to be a powerful tool for the early diagnosis of TB.

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Development of an in-house loop-mediated isothermal amplification (LAMP) assay for detection of Mycobacterium tuberculosis and evaluation in sputum samples of Nepalese patients.

Photobacterium phosphoreum caused a histamine fish poisoning incident.

Histamine-producing bacteria (HPB) such as Photobacterium phosphoreum and Raoultella planticola possess histidine decarboxylase (HDC), which converts histidine into histamine. Histamine fish poisoning (HFP) is attributable to the ingestion of fish containing high levels of histamine produced by HPB. Because freezing greatly decreases the histamine-producing ability of HPB, especially of P. phosphoreum, it has been speculated that HFP is caused by HDC itself from HPB cells autolyzing during frozen storage, even when HPB survive frozen storage. Here we constructed recombinant HDCs of P. phosphoreum, Photobacterium damselae, R. planticola, and Morganella morganii and investigated the ability of HDCs to produce sufficient histamine to cause HFP. To elucidate the character of these HDCs, we examined the specific activity of each recombinant HDC at various temperatures, pH levels, and NaCl concentrations. Further, we also investigated the stability of each HDC under different conditions (in reaction buffer, tuna, and dried saury) at various temperatures. P. damselae HDC readily produced sufficient histamine to cause HFP in fish samples. We consider that if HDC is implicated as an independent cause of HFP in frozen-thawed fish, the most likely causative agent is HDC of P. damselae.

Tomoko Yoda

Papers

Molecular cloning and characterization of the gene coding for azoreductase from Bacillus sp. OY1-2 isolated from soil.

Klebsiella pneumoniae produces no histamine: Raoultella planticola and Raoultella ornithinolytica strains are histamine producers.

Development of an in-house loop-mediated isothermal amplification (LAMP) assay for detection of Mycobacterium tuberculosis and evaluation in sputum samples of Nepalese patients.

Photobacterium phosphoreum caused a histamine fish poisoning incident.

Histidine decarboxylases and their role in accumulation of histamine in tuna and dried saury.