China
Africa
Explore chapters and articles related to this topic
Distribution and Biological Functions of Pyruvate Carboxylase in Nature
Published in D. B. Keech, J. C. Wallace, Pyruvate Carboxylase, 2018
Pyruvate carboxylase is, however, notably absent from the Enterobacteriaceae,31 from Salmonella spp.,866 from some Arthrobacter species,480 and from various methane-oxidizing organisms (viz., Methylosinus trichosporium, Methylomonas methanica, Methylobacter chroococcum, Hyphomicrobium vulgare, and Pseudomonas methylica), though present in others.508
Biosensors for the detection of mycotoxins
Published in Toxin Reviews, 2022
Akansha Shrivastava, Rakesh Kumar Sharma
Microbes as a whole-cell have some advantages as a biological recognition element in biosensors. They can be present all over the surface and effectively metabolize a wide range of chemical compounds. Microorganisms possess an immense capacity to adapt to adverse conditions and the ability to degrade new and different molecules with time. Whole cells can be used either in viable or non-viable forms (D’Souza 2001, Xu and Ying 2011). High cell viability is generally achieved by trapping the microbial cells into the pores of synthetic or biological (cellulose) membranes. A sensitive and convenient biosensor based on E. coli as a biorecognition element was developed for the first time to detect aflatoxin (AFB1) and ZEN. It was hypothetically derived from the findings that AFB1 and ZEN affect the morphology of E. coli similarly to penicillin (an antibiotic from fungi). The reactive groups including hydroxyl and ester of the AFB1 and ZEN bind to membrane proteins to destroy the integrity of the reticulocyte wall of E. coli. Some other factors including the efficiency of bio-transformative pathways, mycotoxin-induced oxidative stress, or the presence of some specific mycotoxin receptors may also influence the toxicity response of mycotoxins. Since much has not been explored yet in this section, a detailed mechanism of other toxins and microbes is still needed for further consideration (Chen et al. 2020). Biorecognition element in the form of the bacterial cell (Photobacterium phosphoreum) immobilization in cryogel was developed for the detection of different mycotoxins under discrete and flow-through analyses. These immobilized bioluminescent cells could be used for the quantification of mycotoxins such as ochratoxin A, sterigmatocystin, ZEN, and deoxynivalenol (DON) (Senko et al. 2019). Apart from whole-cell biosensors for mycotoxin detection, different microbes including Sarcina flava, Azotobacter vinelandii, Methylomonas flagelatis, Enterobacter agglomerans, and Bacterium cadaveris have also been explored for the amino acid sensor in fermentation industry, pharmaceutical industry, healthcare, and food industry (Sharma et al. 2014).