scholarly journals Properties of a new fungal b-galactosidase with potential application in the dairy industry

1999 ◽  
Vol 30 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Rubens Cruz ◽  
Vinícius D'Arcádia Cruz ◽  
Juliana Gisele Belote ◽  
Marcelo de Oliveira Khenayfes ◽  
Claudia Dorta ◽  
...  

<FONT FACE="Symbol">b</font>-Galactosidase or <FONT FACE="Symbol">b</font>-D-galactoside-galactohydrolase (EC. 3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for the synthesis of transgalactosylated oligosaccharides (TOS) that act as functional foods, with several beneficial effects on consumers. Penicillium simplicissimum, a strain isolated from soil, when grown in semi-solid medium showed good productivity of <FONT FACE="Symbol">b</font>-galactosidase with galactosyltransferase activity. The optimum pH for hydrolysis was in the 4.04.6 range and the optimum pH for galactosyltransferase activity was in the 6.07.0 range. The optimum temperature for hydrolysis and transferase activity was 55-60°C and 50°C, respectively, and the enzyme showed high thermostability for the hydrolytic activity. The enzyme showed a potential for several industrial applications such as removal of 67% of the lactose from milk and 84% of the lactose from milk whey when incubated at their original pH (4.5 and 6.34, respectively) under optimum temperature conditions. When incubated with a 40% lactose solution in 150 mM McIlvaine buffer, pH 4.5, at 55°C the enzyme converted 86.5% of the lactose to its component monosaccharides. When incubated with a 60% lactose solution in the same buffer but at pH 6.5 and 50°C, the enzyme can synthetize up to 30.5% TOS, with 39.5% lactose and 30% monosaccharides remaining in the preparation.

1977 ◽  
Vol 75 (2) ◽  
pp. 235-243 ◽  
Author(s):  
J. P. RENSTON ◽  
T. J. IHRIG ◽  
R. H. RENSTON ◽  
B. GONDOS ◽  
R. J. MORIN

The characteristics and localization of a cholesterol ester hydrolase enzyme in homogenates of whole testis and in isolated seminiferous tubules and interstitial cells of mature rats have been investigated. Hydrolysis of cholesteryl [1-14C]oleate occurred at an optimum pH of 7·0 was linearly related to time up to 5–6 h of incubation and increased linearly up to 0·25 mg protein/incubation. Hydrolytic activity was inhibited by increasing the incubation temperature from 29 to 41 °C and by sonication. Cholesterol ester hydrolase activity/mg protein was three times greater in homogenates of seminiferous tubules than in interstitial cells. Cholesterol ester hydrolase may function to provide precursors for use in seminiferous tubular steroid hormone biosynthesis or germ cell maturation.


2017 ◽  
Vol 18 (02) ◽  
pp. 103-108
Author(s):  
Vivitri Dewi Prasasty ◽  
Vinella Winata ◽  
Muhammad Hanafi

Lipases are known as glycerol ester hydrolases that catalyze the hydrolysis of triglycerides into free fatty acids and glycerol. Lipases are found in human, animal, plant, and microorganisms. The aim of this research is to identify lipase producers and characterize bacterial lipase from West Java plateau soil. Plateau soil bacteria samples were isolated on lipase screening medium containing Rhodamine B. Olive oil was used as a substrate in screening and production medium bacterial lipases. From 16 bacterial isolate of lipase producers, 14 were identified as Bacillus sp. and the others were identified as Pseudomonas alcaligenes. All isolates were taken into production step to determine their lipase activities. Moreover, top 3 lipase activities out of 16 lipase activities were chosen to find the optimum pH and temperature. Both characterizations showed pH optimum and temperature optimum from each lipase. These optimum condition were used in heat stability characterization for each lipase samples. The result showed that lipase from isolate COK 2 in optimum pH 4 and temperature 50oC was the most stable lipase due to this sample has good and stable activity for 1 to 5 hours incubation time. Lipase sample from isolate COK 2 has good efficiency for lipase productivity in acid condition and high temperature. Results of this investigation could encourage utilization of these activity enhancers for various industrial applications.


2013 ◽  
pp. 63-69
Author(s):  
Thi Minh Thu Ngo ◽  
Gao-Wei Zheng ◽  
Jian-He Xu

Background: Because of pleasant flavor and aroma as well as cooling-anesthetic effect, menthol and mint oils are widely used in the flavor industry and biocatalytic processes for production of l-menthol are more interested nowadays. Herein, we attempted to develop a biocatalytic process for production of l-menthol through enantioselective hydrolysis of dl-menthyl benzoate using a strain newly isolated from soil. Methods: From soil samples, we were isolated one strain exhibited the best hydrolytic activity and excellent enantioselectivity as compared to others. So, it was selected as the best enzyme producer and subsequently identified as Acinetobacter sp. based on the 99% similarity of its 16S rDNA sequence, and named Acinetobacter sp. ECU2040. The fermentation process was studied and the fermentation gave about 130 g wet cell, which was equivalent to 18 g dry cell. The catalytic properties of Acinetobacter sp. ECU2040 were also studied. The results showed that the optimum pH and temperature of reaction were 7.5 and 37ºC, respectively. Results and conclusion: The strain Acinetobacter sp. ECU2040 strain exhibited the production of l-menthol ability with the best hydrolytic activity and excellent enantioselectivity. Key words: l-menthol, enantioselective, isolated strain


1969 ◽  
Vol 115 (4) ◽  
pp. 733-739 ◽  
Author(s):  
M. Cole

1. A method is given for the preparation of penicillin acylase by using Escherichia coli N.C.I.B. 8743 and a strain selected for higher yield. The enzyme is associated with the bacterial cells and removes the side chains of penicillins to give 6-amino-penicillanic acid and a carboxylic acid. 2. The rates of penicillin deacylation indicated that p-hydroxybenzylpenicillin was the best substrate, followed in diminishing order by benzyl-, dl-α-hydroxybenzyl-, 2-furylmethyl-, 2-thienylmethyl-, d-α-aminobenzyl-, n-propoxymethyl- and isobutoxymethyl-penicillin. Phenylpenicillin and dl-α-carboxybenzylpenicillin were not substrates and phenoxymethyl-penicillin was very poor. 3. Amides and esters of the above penicillins were also substrates for the deacylation reaction, as were cephalosporins with a thienylmethyl side chain. 4. For the deacylation of 2-furylmethylpenicillin at 21° the optimum pH was 8·2. The optimum temperature was 60° at pH7. 5. By using selection A of N.C.I.B. 8743 and determining reaction velocities by assaying yields of 6-amino-penicillanic acid in a 10min. reaction at 50° and pH8·2, the Km for benzylpenicillin was found to be about 30mm and the Km for 2-furylmethylpenicillin, about 10mm. The Vmax. values were 0·6 and 0·24μmole/min./mg. of bacterial cells respectively.


2011 ◽  
Vol 236-238 ◽  
pp. 1793-1798 ◽  
Author(s):  
Hua Zheng Liang ◽  
He Chen ◽  
Jian Feng Wang ◽  
Yu Lan He

Co-immobilize enzyme by cross-linking and embedding, optimize conditions for immobilizing, determinate the enzymatic properties of co-immobilized enzyme and study the methods for preparation of genipin using co-immobilized enzyme to hydrolyze geniposide. Optimized immobilizing conditions include glutaraldehyde concentration being 0.15%, cross-linking temperature being 20°C, cross-linking time being 2 hours, the activity of co-immobilized β-glucosidase and cell reaches to 65.33U/mg and the enzyme activity recovery being 52.63%. Enzymatic properties of co-immobilized enzyme are following: optimum temperature is 55°C and optimum pH is 5.0. The transformation experiments are carried out with co-immobilized enzyme. The results show that half-life of co-immobilized enzyme reaches around 40 days, higher than the normal immobilized enzyme. The conversion rate of geniposide is above 95% after 8 hours. The genipin is isolated, purified and recrystallized to reach more than 98% of purity by High Performance Liquid Chromatography. Advantages to prepare genipin using co-immobilized enzyme include low cost, high yield, environmental friendly and easy to manufacturing.


2020 ◽  
Vol 13 (2) ◽  
pp. 228-241
Author(s):  
Ika Rahmatul Layly ◽  
Erma Widyasti ◽  
Deden Rosid Waltam ◽  
Ayi Mufti ◽  
Nita Wiguna ◽  
...  

AbstrakLipase adalah kelompok enzim yang mengkatalisis hidrolisis rantai panjang trigliserida, lemak, dan minyak menjadi gliserol dan asam lemak dengan adanya air. Sumber lipase untuk industri kebanyakan berasal dari mikroorganisme. Penggunaan lipase pada industri makin meningkat setiap tahunnya meliputi aplikasinya pada industri makanan, pakan, farmasi, pulp, dan kertas, biodiesel, dan industri tekstil. Dalam usaha mendapatkan isolat potensial penghasil lipase untuk hHidrofilisasi serat poliester, pada penelitian ini dilakukan skrining dan isolasi mikroorganisme yang dapat menghasilkan lipase dari limbah pengolahan minyak kelapa sawit di Malinping, Lebak, Banten. Sebanyak 20 isolat bakteri dan 5 isolat jamur yang diperoleh kemudian diuji aktivitas lipasenya menggunakan metode titrasi. Empat isolat bakteri terpilih (Kondensat, Lumpur-Got, Hasil-Buangan, dan Tangki-Crude-Oil) serta lima isolat jamur (Nut-A, Nut-B, Nut-C, Kernel-B, dan Kernel-C) dikarakterisasi pH dan suhu optimum enzimnya. Hasil karakterisasi pH menunjukkan bahwa isolat bakteri Kondensat, Lumpur-Got, Hasil-Buangan, dan Tangki-Crude-Oil mempunyai aktivitas enzim lipase tertinggi pada pH 6. Suhu optimal aktivitas enzim lipase isolat Lumpur-Got-B, Hasil Buangan-B, dan Tangki-Crude-Oil B  pada 40 °°C, sedangkan isolat bakteri-Kondensat-B optimal pada suhu 30 °°C. Aktivitas lipase kelima isolat jamur optimal pada pH 6. Suhu optimal aktivitas lipase isolat jamur Nut-A adalah 40 °°C, sedangkan isolat Nut-B, Nut-C, Kernel-B, dan Kernel-C aktivitasnya optimal pada 50 °°C.Abstract Lipase are enzymes that catalyzed the hydrolysis of triglyceride, fats and oils into glycerol and fatty acids in the presence of water. Industrial Lipase source mostly derived from microbes. Each year, the lipase utilization in industry increased, such as application for foods, feeds, pharmacys, pulp and papers, biodiesel, and textile industries. On this study, a total of 20 bacteria and 5 fungi lipase potential producer were screened and isolated from oil palm processing waste in Malinping, Lebak, Banten, which then tested for its activity using titration method. Selected isolates then were characterized for its enzyme optimum pH and temperature. The optimum pH for isolate Kondensat, Lumpur-Got, Hasil-Buangan and Crude-Oil-Tank lipases are at pH 6, whilst the optimum temperature of isolates Lumpur-Got B, Hasil-Buangan B and Crude-Oil-Tank B were at 40 °°C and bakteri-Kondensat B isolate optimum at 30 °°C. The five fungi characterization shown optimum pH at 6 and 50 °°C except for isolate Nut-A that optimum at 30 °°C.


2021 ◽  
Vol 226 ◽  
pp. 00042
Author(s):  
Sri Sugiwati ◽  
Suaidah Suaidah ◽  
Eka Triwahyuni ◽  
Muryanto Muryanto ◽  
Yosie Andriani ◽  
...  

Oil palm empty fruit bunch (OPEFB) constitutes a great source of lignocellulosic biomass, mainly comprising of 66.97 % of holocellulose (cellulose and hemicellulose) and 24.45 % of lignin. This present work aimed to hydrolyze cellulose present in OPEFB to form glucose with the aid of Aspergillus niger. A. niger is a type of filamentous fungi able to produce cellulase, a multi-enzyme complex consisting of an endoglucanase, exoglucanase, and β-glucosidase, able to converting cellulose into glucose. The glucose produced is then fermented to produce bioethanol. The present study compared hydrolytic activity of cellulose between OPEFB with pretreatment using NaOH 10 % and OPEFB without pretreatment, concerning temperature, pH, and hydrolysis time. The concentration of reducing sugar derived from cellulosic hydrolysis was determined by using a glucose assay of 3.5-dinitrosalicylic acid. The results showed that the optimum temperature for hydrolysis of cellulose OPEFB (pretreated and untreated) was at 40 °C and the optimum pH was 5.0 for OPEFB-untreated and 5.5 for OPEFB-pretreated. Hydrolysis of cellulose at 40 °C and 3 d yielded reducing sugar 13.01 mg mL−1 and 1.16 mg mL−1 for OPEFB-untreated and OPEFB-pretreated, respectively.


2016 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Omar M. Atrooz

<p>β-galactosidase (EC 3.2.1.23) was extracted from <em>Cuminum cyminum </em>and<em> Curcuma longa</em>. The crude extracts of these plants were then characterized in term of pH, temperature, and enzyme kinetic. The crude extracts were also used in hydrolysis of lactose in milk and whey. The enzyme activity was measured by its ability to hydrolyze the substrate o-nitrophenyl β -D-galactopyranoside (ONPG).</p><p>It was found that β-galactosidase in the crude extracts of <em>Cuminum cyminum </em>exhibited maximum activity at pH 8.0 and optimum temperature at 60 °C. While, β-galactosidase in the crude extracts of <em>Curcuma longa</em> have optimum pH at 5.0 and 7.0 and optimum temperature at 50 °C.The K<sub>m</sub> and V<sub>max</sub> values of the β-galactosidase in the crude extracts of <em>Cuminum cyminum</em> and <em>Curcuma longa </em>were 4.16 mM and 0.087 μmol/min, and 2.63 mM and 0.333μmol/min, respectively.</p><p>The results showed that 96.84-97.08% of lactose was hydrolyzed in cow’s milk and whey when treated with crude extracts of <em>Cuminum cyminum</em> and 90-98.6% when treated with crude extracts of <em>Curcuma longa</em>.</p>


1977 ◽  
Vol 40 (6) ◽  
pp. 375-377 ◽  
Author(s):  
AZZA A. ISMAIL ◽  
N. S. AHMED ◽  
M. A. KHORSHID

A procedure was developed for isolation and identification of ribonuclease from buffalo milk whey. Ribonuclease was precipitated with (NH4)2SO4 between 65 and 90% saturation. The precipitate was dissolved, dialyzed, and fractionated on DEAE-cellulose. Two ribonuclease-rich fractions were collected, i.e. ribonuclease A and B. Ribonuclease A had an optimum pH of 7 .0, and ribonuclease B had an optimum pH of 8.6. Both had an optimum temperature at 38 C. The ribonucleases in the purified state were unstable to heat and their activity decreased as the time of exposure increased. Both enzyme fractions were sensitive to inhibitors. NaCl and NaN3 were stimulatory for ribonuclease A, while ribonuclease B was stimulated only by NaCl.


2021 ◽  
Author(s):  
Karolline Christiny Szeremeta da Silva ◽  
Yuri Carvalho ◽  
Eduardo Falabella Sousa-Aguiar

Abstract β-glucosidase was used as catalyst for the hydrolysis of cellobiose, immobilized on different supports, including two silicas (MSNS and MCM-41) and three carbon supports (GAC, BDH and Norit). It was observed that mesoporous nanoparticles are better candidates as supports for the β-glucosidase, and that silica has a better performance, probably due to the presence of silanol groups. The MSNS showed better recovered activity compared to other supports, showing an optimum temperature at 70 0 C and an optimum pH of 5. The enzyme immobilized in MSNS showed results 80% to 98% better than those immobilized on other supports. However, for the recycling test, from the second cycle onwards, the MSNS showed a performance drop of around 40%, reaching a relative activity of 41.9% for both the fourth and the final cycle. MCM-41, on the other hand, did not show as much discrepancy in the recycling test. However, its relative activity in the first cycle was 20% of the activity achieved by MSNS, at its optimum temperature of 60 0 C. Such results indicate that the smaller particle size favours enzymatic activity. Notwithstanding, a larger available intra-pore surface area protects the enzyme from denaturation.


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