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Omics Approaches for the Production of the Microbial Enzymes and Applications
Published in Pankaj Bhatt, Industrial Applications of Microbial Enzymes, 2023
Heena Parveen, Anuj Chaudhary, Parul Chaudhary, Rabiya Sultana, Govind Kumar, Priyanka Khati, Meenakshi Rana, Pankaj Bhatt
Dehydrogenases are oxidoreductases that can be found in bacteria, yeast, plants, and animals [30–34]. Dehydrogenases use a coenzyme like NAD+/NADP+ as an electron acceptor to catalyze the oxidation-reduction reaction. Alcohol dehydrogenase enzymes convert alcohol into aldehydes or ketones. Other aromatic dehydrogenases reported include naphthalene dihydrodiol dehydrogenase, polyethylene glycol dehydrogenase, benzyl alcohol dehydrogenase, and others [35]. Previously, bacterial cell-free extracts digest the industrially generated xenobiotics of various molecular weights, and the polyethylene glycol dehydrogenase activity was detected [36]. Similarly, another dehydrogenase, dye-linked polypropene glycol dehydrogenase in the periplasm or membrane of Stenotrophomonas maltophilia, is energetic in high-molecular-weight PPG degradation, whereas a cytoplasm-located enzyme was found to be active in hydrolyzing low-molecular-weight composite [37]. In a recent study, a novel dehydrogenase, 17β-hydroxysteroid dehydrogenase (17β-HSDx) present in Rhodococcus sp. P14, showed better activity in steroid bioremediation [38]. In previous studies, Rhodococcus sp. was originally involved in the degradation of various polycyclic aromatic hydrocarbons.
Bioprospecting Extremophiles for Sustainable Biobased Industry
Published in Pratibha Dheeran, Sachin Kumar, Extremophiles, 2022
Neha Basotra, rashika Raheja, Gaurav Sharma, Kumud Ashish Singh, Diksha Sharma, Rohit Rai, Bhupinder Singh Chadha
A thermostable nucleoside phosphorylase has been characterized from hyperthermophilic aerobic crenarchaeon Aeropyrum pernix K1 and has been used for the synthesis of nucleoside analogues used in antiviral therapies as an alternative to chemical synthesis (Zhu et al. 2013). Other thermozymes also include proteases like thermolysin used in the synthesis of dipeptides, pretaq protease used to clean DNA prior to PCR amplification, and starch-processing and DNA-processing enzymes (Jayakumar et al. 2012). In addition to the above mentioned extremozymes, other enzymes are also suitable for use in further industrial processes. For example, alcohol dehydrogenases can be used to synthesize building blocks for the chemical industry, such as optically active alcohols, or to synthesize cofactors such as NAD and NADP. Meanwhile, nitrile-degrading enzymes are of interest for the transformation of nitriles and carbon-carbon bond forming enzymes like aldolases, transketolases and hydroxynitrile lyases are useful in organic synthesis (Resch et al. 2011, Demiriian et al. 2001).
Biotransformation of Xenobiotics in Living Systems—Metabolism of Drugs: Partnership of Liver and Gut Microflora
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2020
The primary site of alcohol metabolism is the liver. The main pathway of ethanol metabolism involves its conversion to acetaldehyde, an oxidative reaction that is catalyzed by enzymes known as alcohol dehydrogenases. In a second reaction mediated by aldehyde dehydrogenase, acetaldehyde is oxidized to acetate (Fig. 6.7). Other enzymes, such as cytochrome P450 (e.g., CYP2E1), metabolize a small fraction of the ingested ethanol (Edenberg, 2007). Some drugs may inhibit the activity of aldehyde dehydrogenase leading to the accumulation of acetaldehyde during ethanol ingestion, which is associated with flushing, nausea and vomiting, palpitations and dyspnea. The well-known interaction is between disulfiram and ethanol. Because of its ability to cause these extremely unpleasant symptoms, disulfiram may be used to effectively treat alcohol dependence (Kitson, 1977). Other drugs that can cause disulfiram-like effects when administered concurrently with ethanol include chloramphenicol, furazolidone (Karamanakos et al., 2007) and some of cephalosporin antibiotics (Ren et al., 2014).
Overview of biological mechanisms of human carcinogens
Published in Journal of Toxicology and Environmental Health, Part B, 2019
Nicholas Birkett, Mustafa Al-Zoughool, Michael Bird, Robert A. Baan, Jan Zielinski, Daniel Krewski
Ethanol is metabolized to acetaldehyde by three major pathways: the alcohol dehydrogenase (ADH) pathway, the microsomal ethanol oxidizing cytochrome P450 (CYP) pathway, and the catalase-H2O2 system. Acetaldehyde, to which many deleterious effects of ethanol can be attributed, is oxidized to acetate primarily by aldehyde dehydrogenases (ALDHs). Over the past decade, epidemiological evidence of enhanced cancer risks among heterozygous carriers of the inactive ALDH enzyme has become much stronger, in particular for esophageal cancer: practically all studies conducted in East-Asian populations who consumed alcoholic beverages show significantly increased odds ratios for carriers of the inactive ALDH allele. In addition, several studies have demonstrated associations between the polymorphism of ADH1B and upper aero-digestive tract cancers, which have been explained either by more active ADH producing more acetaldehyde or by less active ALDH causing prolonged exposure to lower levels of ethanol-derived acetaldehyde. These data imply that acetaldehyde is the key compound in the development of cancers of the esophagus and other upper aero-digestive tract cancers associated with alcoholic beverage consumption
Temperature-induced recovery of a bioactive enzyme using polyglycerol dendrimers: correlation between bound water and protein interaction
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Tooru Ooya, Takaya Ogawa, Toshifumi Takeuchi
Alcohol dehydrogenase (ADH) is a widely studied enzyme for biotechnology applications. Supporting materials are required to recover ADH because free ADH cannot be reused due to its lack of long term stability under processing conditions and that it is difficult to recover from the reaction mixture. When ADH is dissolved in aqueous solution, its thermal and chemical denaturation occurs because the folded structure is lost. Many researchers have used additives and preservatives, including poloxamer [8], trehalose [9,10], and glycerol [11–15], to prevent protein unfolding and obstruction of the active sites upon recovery and reuse.