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Rapid, Automated and Online Detection of Indicator Bacteria in Water
Published in Maximilian Lackner, Philipp Stadler, Wilhelm Grabow, Handbook of Online and Near-real-time Methods in Microbiology, 2017
Trude Movig, Henrik Braathen, Helene Stenersen
The methods are easy to use and are in general based on the detection of a visual end-product. The analysis time for drinking water samples is still between 14–24 hours (Tryland et al. 2015). Reduction in analysis time may be achieved by use of sensitive instrumentation to detect released chemiluminescence (Van Poucke and Nelis 1995), colored (Apte et al. 1995) or fluorescent end-products (Tryland et al. 2001). These are incorporated into substrates usually based on galactosides, including lactose (Fig. 2). The substrates with a chemiluminescent end-product are typically 3-(4-methoxyspiro)-1,2-dioxetane-3,2′-tricyclo[3.3.1.1]decan-(4-yl)phenyl- β-d-galactopyranoside (AMPGD). The substrates with a colored end- product are usually 2-nitrophenyl β-D-galactopyranoside (OPNG) and substrates with fluorescent end-product are usually 4-methylumbelliferone β-D-galactopyranoside (MU-Gal). The detectable end-product is released after reaction by the bacterial enzymes which cleave the glycosidic bond between galactose and the end-product. Similar glucuronide-based substrates are also available for specific E.coli glucuronidase activity.
Extremophilic Microbes and their Extremozymes for Industry and Allied Sectors
Published in Ajar Nath Yadav, Ali Asghar Rastegari, Neelam Yadav, Microbiomes of Extreme Environments, 2021
Hiran Kanti Santra, Debdulal Banerjee
β-D-Galactosidase (EC 3.2.1.23) with the systematic name of β-D-galactoside galactohydrolase is an exoglycosidase that hydrolysizes the terminal non reducing β-D-galactoside residue in β-D-galactosides (Wanarska and Kur 2005). The common β-D-galactoside is a lactose made up of D-glucose and D-galactose. In high lactose concentration glucosyl transferase activity is also exhibited (Cruz et al. 1999). Onishi and Tanaka (1996) reported β-D-glucosidase, β-D-fucosidase and α-L-arabinosidase activity of β-D-galactosidase of Rhodotorula minuta IFO897.
Microbial enzymes and potential use in algal polysaccharide modifications
Published in Antonio Trincone, Enzymatic Technologies for Marine Polysaccharides, 2019
Daniela de Borba Gurpilhares, Lara Durães Sette, Adalberto Pessoa
A great diversity of enzyme has successfully been applied in food (animal and human) and beverage industries. Pectin is a complex structural heteropolysaccharide commonly found in juice, wine, and beer. Numerous pectinolytic enzymes are required for complete degradation of pectin, and their use may improve the clarification process of such products (Ramya and Pulicherla 2015). Acidophilic pectinases have extensive applications in the extraction and clarification of fruit juices and wine, while alkaline pectinases can be used in coffee and tea fermentations. Pectinases in a cocktail also containing glucanases, xylanases, proteases, and amylases promote increase in nutrients absorption and reduction of feces during animal and poultry feed (Hoondal et al. 2002). Pectinases or polygalacturonases (PGases) are the enzymes that depolymerize pectin by cleavage of glycosidic bonds (Ramya and Pulicherla 2015). β-Galactosidase (β-d-galactoside–galactohydrolase, EC 3.2.1.23) hydrolyzes lactose to glucose and galactose, and lactose hydrolysis is becoming a promising process in the food industry for the development of lactose-free products (Song et al. 2010a). Yeasts such as Kluyveromyces lactis, Kluyveromyces marxianus, and Candida kefyr, have been considered as the predominant microbial β-galactosidase source for food applications (Song et al. 2010b). As an example, β-galactosidase from Kluyveromyces lactis have been evaluated for the removal of residual lactose in crude galactooligosaccharides (GOS), one of the few non-digestible oligosaccharides considered as prebiotics (Santibáñez et al. 2016). β-Galactosidase not only cleaves lactose but also involves a transgalactosylation reaction to produce galactooligosaccharides (Kamran et al. 2016). In another way, α-galactosidase (α-d-galactoside galactohydrolase, EC 3.2.1.22) catalyzes the hydrolysis of terminal α-1,6-linked d-galactose residues present in galactooligosaccharides of the raffinose family sugars and galactomannan polysaccharides. This enzyme has potential use for processing legume-based food products, since it reduces the amount of antinutritional compounds (Viana et al. 2007).
A β-galactosidase-expressing E. coli culture as an alternative test to identify skin sensitizers and non-sensitizers
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Mahesh Raj Nepal, Youra Kang, Mi Jeong Kang, Doo Hyun Nam, Tae Cheon Jeong
The production of β-galactosidase enzyme by LacZ gene expression is one of the widely used tools that has been applied to assess the toxicity produced by chemicals, particularly by monitoring the efficiency of intracellular gene expression (Bitton and Koopman 1992; Li et al. 2012). The enzyme β-galactosidase, a product of LacZ gene, catalyzes hydrolysis of β-D-galactosides into their monosaccharide units including galactose and glucose from lactose (Juers, Matthews, and Huber 2012). When lactose or its analogue, isopropyl β-D-1-thiogalactopyranoside (IPTG), stimulates gene expression of LacZ, Hamilton and Lo (1978) found that production of β-galactosidase enzyme was markedly enhanced. Li et al. (2012) took advantage of enzyme substrate specificity by synthesizing O-nitrophenyl galactopyranoside (ONPG) which might be hydrolyzed by β-galactosidase to the spectrophotometrically measurable product, o-nitrophenol.
Production and partial purification by PEG/citrate ATPS of a β-galactosidase from the new promising isolate Cladosporium tenuissimum URM 7803
Published in Preparative Biochemistry & Biotechnology, 2021
Anderson José Paulo, Maria Carolina de Albuquerque Wanderley, Rafael José Vilela de Oliveira, Willie Anderson dos Santos Vieira, Luiz Carlos Alves, Daniela de Araújo Viana Marques, Attilio Converti, Ana Lúcia Figueiredo Porto
β-galactosidases (EC3.2.1.23) are hydrolases capable of hydrolyzing the β-galactopyranosyl terminal residue of lactose (Galβ1-4Glc) to form glucose and galactose as well as the reverse reaction, i.e., sugar condensation to galacto-oligosaccharides (GOS). Therefore, they are able to split β-galactosyl bonds in glycoproteins, polysaccharides, disaccharides and other compounds such as o- and p-nitrophenyl-β-D-galactosides used to determine β-galactosidase activity. Also known as lactases, they are among the most studied enzymes.[1]