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Microbial Valorization of Food Industry Wastes for Production of Nutraceutical Molecules
Published in Jitendra Kumar Saini, Surender Singh, Lata Nain, Sustainable Microbial Technologies for Valorization of Agro-Industrial Wastes, 2023
K. Ranjitha, Vijay Rakesh Reddy, Harinder Singh Oberoi
Galactooligosaccharides (GOS) are important prebiotics synthesized conventionally from lactose by a special enzyme called β-galactosidase (EC 3.2.1.23). β-galactosidases are very commonly produced enzymes across microbial groups. This enzyme hydrolytically splits the lactose as well as catalyzes transgalactosylation to produce galactooligosaccharides (Prenosil et al., 1987). Instead of using pure enzymes, GOS production through microbial cell factories is explored. Recently, GOS production from dairy effluents using mixed cultures of Bacillus singularis and Saccharomyces sp. was patented in the USA (US9139856B2—process for the production of galactooligosaccharides [GOS], Google Patents). The system is claimed to have more economic advantage by making possible the repeated use of cell biomass and by obtaining pure GOS without interference from galactose.
Lactulose: A High Food Value-Added Compound and Its Industrial Application in Food
Published in Deepak Kumar Verma, Ami R. Patel, Sudhanshu Billoria, Geetanjali Kaushik, Maninder Kaur, Microbial Biotechnology in Food Processing and Health, 2023
Enzymatic-based lactulose production is receiving more attention regarding to the synthesis feasibility and environmental considerations in comparison to chemical lactose to lactulose isomerization (Schuster-Wolff-Bühring et al., 2010). Additionally, the pure substrates are not required for lactulose synthesis through enzymatic route, and whey/whey permeates can be applied as lactose sources. A well, the mild reaction conditions and good selectivity result in a manifestly lower downstream operation costs (Guer-rero and Wilson, 2016). β-galactosidase and glycosidase are commonly employed for lactulose production, and β-galactosidase is a well-docu-mented catalyst for trans-galactosylation reaction (Panesar and Kumari, 2011). In enzymatic-mediated lactulose synthesis and through a rapid trans-galactosylation mechanism, β-galactosidase leads to lactose hydrolysis to glucose and galactose in order to form a galactosyl-β-galactosidase intermediate complex. In the final stage, the galactosyl moiety is transferred to one fructose molecule, as an acceptor, and yields bioactive lactulose (Figure 6.5) (Wang et al., 2013).
Natural enzymes used to convert feedstock to substrate
Published in Ruben Michael Ceballos, Bioethanol and Natural Resources, 2017
Galactosidases are glycoside hydrolases that catalyze the hydrolysis of galactosides into monosaccharides. There are two types of galactosidases. AGLs (e.g., EC 3.2.1.22), which belong to GH4, 27, 31, 36, 57, 97, and 110 families, release α-linked d-galactose residues from hemicellulose (i.e., xylan or galactomannan) by acting at the nonreducing terminal ends (Ademark et al., 2001; Lombard et al., 2014; CAZy, 2015). LACs (e.g., EC 3.2.1.23), belong to GH1, 2, 35, 42, and 59 families (Lombard et al., 2014; CAZy, 2015). LACs hydrolyze the nonreducing ends of β-d-galactose residues from hemicellulose (i.e., xylan, xyloglucan, or galactoglucomannan) (Sims et al., 1997). The βGs (EC 3.2.1.21) are also exotype enzymes that remove the 1,4-β-d-glucopyranose units from the nonreducing ends of oligosaccharides from the breakdown of glucomannan and galactoglucomannan by MAN (Moreira and Filho, 2008).
Production, purification, characterization, and applications of α-galactosidase from Bacillus flexus JS27 isolated from Manikaran hot springs
Published in Preparative Biochemistry & Biotechnology, 2023
Sonu Bhatia, Navneet Batra, Jagtar Singh
α-Galactosidase has been isolated and characterized from the microbial, plant, and animal sources. Bacterial sources include Bacteroides ovatus, Bifidobacterium breve, Lactobacillus acidophilus, Pontibacter sp., Streptococcus pneumoniae, etc., while, Aspergillus niger, Aspergillus satoi, Candida albicans, Penicillium chrysogenum, etc. are significant fungal sources. The enzyme has also been isolated from plants including Ceretonia siliqua, Cicer arietinum, Coffea arabica, Nicotiana tabacum, Vicia faba whereas humans, pigs, rats, rabbit, etc. are major animal sources.[2,3] Most commercialized microorganisms include strains of Lactobacillus and Aspergillus.
The effect of mass transfer on reaction rates during immobilized β-galactosidase-catalyzed conversion of lactose in hollow fiber membrane
Published in Chemical Engineering Communications, 2019
Fadzil Noor Gonawan, Mohamad Zailani Abu Bakar, Khairiah Abd Karim, Azlina Harun Kamaruddin
Lactose can be converted to valuable galacto-oligosaccharides (GOS) by β-galactosidase in two step reactions of hydrolysis and transgalactosylation (Figure 1). The inhibition of β-galactosidase (β-gal) by galactose and a hydrolysis side reaction always reduced the GOS yield. A continuous system of enzymatic membrane reactor (EMR) has been proposed to solve these drawbacks (Czermak et al., 2004; Chockchaisawasdee et al., 2005; Engel et al., 2007; Splechtna et al., 2007; Gonzalez et al., 2009; Das et al., 2010; Nath et al., 2013; Pocedičová et al., 2010; Sen et al., 2011; Ren et al., 2015; ). The EMR system is preferable for β-gal-catalyzed synthesis of GOS due to its separation mechanism. The concept of simultaneous catalytic reaction and separation has been a point of interest in the utilization of the membrane reactor for various enzymatic synthesis (Giorno and Drioli, 2000). This bi-operational mechanism is expected to improve bio-catalytic performance by the removal of the undesirable by-product (inhibitor) and the recovery of the main product from the reaction media. As such, longer bio-catalytic activity is attained, preventing any further side reaction on the main product (GOS).
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.