scholarly journals A Novel Neutral and Mesophilic β-Glucosidase from Coral Microorganisms for Efficient Preparation of Gentiooligosaccharides

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2985
Author(s):  
Hongfei Su ◽  
Qi Zhang ◽  
Kefu Yu ◽  
Chunrong Lu ◽  
Zhenlun Xiao ◽  
...  

β-glucosidases can produce gentiooligosaccharides that are lucrative and promising for the prebiotic and alternative food industries. However, the commercial production of gentiooligosaccharides using β-glucosidase is challenging, as this process is limited by the need for high thermal energy and increasing demand for the enzyme. Here, a putative β-glucosidase gene, selected from the coral microbial metagenome, was expressed in Escherichia coli. Reverse hydrolysis of glucose by Blg163 at pH 7.0 and 40 °C achieved a gentiooligosaccharide yield of 43.02 ± 3.20 g·L−1 at a conversion rate of 5.38 ± 0.40%. Transglycosylation of mixed substrates, glucose and cellobiose, by Blg163 consumed 21.6 U/0.5 g glucose/g cellobiose, achieving a gentiooligosaccharide yield of 70.34 ± 2.20 g·L−1 at a conversion rate of 15.63%, which is close to the highest yield reported in previous findings. Blg163-mediated synthesis of gentiooligosaccharides is the mildest reaction and the lowest β-glucosidase consumption reported to date.

Biologia ◽  
2009 ◽  
Vol 64 (6) ◽  
Author(s):  
Yue-Hong Wang ◽  
Yu Jiang ◽  
Zuo-Ying Duan ◽  
Wei-Lan Shao ◽  
Hua-Zhong Li

AbstractIn this study, a new α-glucosidase gene from Thermoanaerobacter ethanolicus JW200 was cloned and expressed in Escherichia coli by a novel heat-shock vector pHsh. The recombinant α-glucosidase exhibited its maximum hydrolytic activity at 70°C and pH 5.0∼5.5. With p-nitrophenyl-α-D-glucoside as a substrate and under the optimal condition (70°C, pH 5.5), K m and V max of the enzyme was 1.72 mM and 39 U/mg, respectively. The purified α-glucosidase could hydrolyze oligosaccharides with both α-1,4 and α-1,6 linkages. The enzyme also had strong transglycosylation activity when maltose was used as sugar donor. The transglucosylation products towards maltose are isomaltose, maltotriose, panose, isomaltotriose and tetrasaccharides. The enzyme could convert 400 g/L maltose to oligosaccharides with a conversion rate of 52%, and 83% of the oligosaccharides formed were prebiotic isomaltooligosaccharides (containing isomaltose, panose and isomaltotriose).


2012 ◽  
Vol 550-553 ◽  
pp. 1177-1181
Author(s):  
Fei Zhang ◽  
Yin Liu ◽  
Pei Xin He

γ-L-glutamyl alkylamines have potential medicinal value. In this research, five different γ-L-glutamyl alkylamines were synthesized. The result showed that substrate specificity of alkylamines, from high to low, is methylamine, ethylamine, n-propylamine, isopropylamine and n-butylamine. The reaction was optimal at pH 9.5 and 45°C, and the optimal substrate mole ratio of L-glutamine to alkylamine was 1:3 (mol/mol).Under these conditions, conversion rate of L-glutamine is about 90% (mol/mol).


2001 ◽  
Vol 45 (9) ◽  
pp. 2598-2603 ◽  
Author(s):  
Laurent Poirel ◽  
Gerhard F. Weldhagen ◽  
Thierry Naas ◽  
Christophe De Champs ◽  
Michael G. Dove ◽  
...  

ABSTRACT Pseudomonas aeruginosa GW-1 was isolated in 2000 in South Africa from blood cultures of a 38-year-old female who developed nosocomial pneumonia. This isolate harbored a self-transferable ca. 100-kb plasmid that conferred an expanded-spectrum cephalosporin resistance profile associated with an intermediate susceptibility to imipenem. A β-lactamase gene, bla GES-2, was cloned from whole-cell DNA of P. aeruginosa GW-1 and expressed in Escherichia coli. GES-2, with a pI value of 5.8, hydrolyzed expanded-spectrum cephalosporins, and its substrate profile was extended to include imipenem compared to that of GES-1, identified previously in Klebsiella pneumoniae. GES-2 activity was less inhibited by clavulanic acid, tazobactam and imipenem than GES-1. The GES-2 amino acid sequence differs from that of GES-1 by a glycine-to-asparagine substitution in position 170 located in the omega loop of Ambler class A enzymes. This amino acid change may explain the extension of the substrate profile of the plasmid-encoded β-lactamase GES-2.


2004 ◽  
Vol 27 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Shu-Chuan Jao ◽  
Li-Fang Huang ◽  
Ying Shin Tao ◽  
Wen-Shan Li

1967 ◽  
Vol 5 (4) ◽  
pp. 13-15

Many hospitals are currently having difficulties in obtaining adequate supplies of i. v. fluids. Staff shortages and increased demand for special sterile bottled solutions for other purposes, for example in operating theatres, for peritoneal dialysis and for haemodialysis, have compelled many hospital pharmacy departments to reduce their output of i. v. fluids. Commercial production of i.v. fluids has not kept pace with the rapidly increasing demand. The quality of i.v. fluids varies considerably:1 pharmacopoeial standards are often not stringently applied, and some of them need revision.


2021 ◽  
Vol 2 (2) ◽  
pp. 100-104
Author(s):  
Arnanda Dhafin Rizky ◽  
Sutrisno Sutrisno ◽  
Parlan Parlan

Saponification tamarind seed oil used potassium hydroxide and acidification with hydrochloric acid is produced fatty acid in the form of soft white solid, has melting point 50-55 degrees celcius. The result of this hydrolysis positive test of unsaturation. It has an acid number of 115.36, saponification number of 114.80, and iodine number of 53.34. The success of hydrolysis of oil into fatty acid is characterized by identification of IR spectra showing O-H vibration with moderate intensity and widening, C=O vibration of carboxylic acid with strong intensity. Fatty acids of tamarind seed have the potential as antibacterial to test bacteria Staphylococcus aureus and Escherichia coli with diameter respectively 7.31 mm and 7.58 mm. Minyak biji asam jawa yang disaponifikasi menggunakan kalium hidroksida dan pengasaman dengan asam klorida dihasilkan asam lemak berupa padatan lunak berwana putih, memiliki titik lebur 50-55 derajat celcius. hasil hidrolisis ini positif uji ketidakjenuhan, bilangan asam 115,36, bilangan penyabunan 114,80, dan bilangan iod 53,34. Keberhasilan hidrolisis minyak menjadi asam lemak ditandai dari identifikasi spektrum IR yang menunjukkan vibrasi ulur O-H dengan intensitas sedang dan melebar serta vibrasi ulur C=O asam karboksilat dengan intensitas kuat. Asam lemak biji asam jawa berpotensi sebagai antibakteri terhadap bakteri uji Staphylococcus aureus dan Escherichia coli dengan zona hambat masing-masing 7,31 mm dan 7,58 mm.


Author(s):  
Irwandi Jaswir ◽  
Hassan Abdullah Al-Kahtani ◽  
Fitri Octavianti ◽  
Widya Lestari ◽  
Nurlina Yusof

Gelatin is an important protein produced through partial hydrolysis of collagen from animal parts and byproducts such as cartilage, bones, tendons, and hides. The ability of gelatin to form a thermo-reversible gel at normal body temperature and high water content make it an exceptional food ingredient. A good quality gelatin is translucent, brittle, colorless (sometimes slightly yellow), bland in taste, and odorless. Gelatin has been found useful as stabilizer and filler in dairy products and other food industries. Recently, the global gelatin production net over 300,000 metric tons: 46% were from pigskin, 29.4% from bovine hides, 23.1% from bones, and 1.5% from other parts. Although camels have been recognized as source of meat and milk, utilization of camel bones and skins for gelatin production has not been fully explored. This chapter will discuss the processing of camel gelatin extraction.


2015 ◽  
Vol 59 (12) ◽  
pp. 7894-7898 ◽  
Author(s):  
S. D. Kotsakis ◽  
V. Miriagou ◽  
E. E. Vetouli ◽  
E. Bozavoutoglou ◽  
E. Lebessi ◽  
...  

ABSTRACTThe cephalosporinase CMY-107, a Tyr199Cys mutant form of CMY-2 encoded by an IncI self-transferable plasmid carried by anEscherichia coliclinical strain, was characterized. The enzyme hydrolyzed oximino-cephalosporins and aztreonam more efficiently than CMY-2 did.


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