EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2013
·Vol. 236
·期 5
·817-826
·
IF 1.436
Zhang Hongzhi,Li Wei,Rui Xin,Sun Xingmin,Dong Mingsheng
A novel food-grade strain Lactobacillus plantarum 70810 producing β-galactosidase with high transgalactosylation activity was isolated from Chinese paocai. The galactooligosaccharides (GOS) were synthesized by using this enzyme with a maximum yield of 44.3 % (w/w) from 400 g/L lactose at 45 °C for 10 h. The β-galactosidase from this strain was purified to homogeneity by ammonium sulfate precipitation, anion exchange chromatography and gel filtration chromatography. It was a heterodimer arrangement of approximately 105 kDa composed of two subunits of 35 and 72 kDa. The optimal pH of the purified β-galactosidase was 8.0 for both o -nitrophenyl-β- d -galactopyranoside ( o NPG) and lactose hydrolysis, and optimal temperature was 60 °C and 55 °C, respectively. Its K
m
and V
max values for o NPG and lactose were 0.89 ± 0.05 mM, 194 ± 3.0 μmoL/min/mg protein, and 9.88 ± 0.16 mM, 15.88 ± 0.21 μmoL/min/mg protein, respectively. This enzyme was slightly inhibited by the hydrolysis products, that is, glucose and galactose. Since the β-galactosidase from L. plantarum 70810 exhibited higher transgalactosylation activity, strong affinity for lactose and low end-product inhibition, it was suggested to be a potential candidate for the synthesis of prebiotic GOS.
研究领域:
食品科学
·
微生物学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yun Shao,Ni Gan,Bingbing Gao,Bingfang He
The production of low-lactose and lactose-free milk remains a critical challenge. Novel enzyme immobilization integrated with the flow reactor that could be applied to hydrolyze milk with cost-effectiveness, facilitation, and safety is highly expected. Here, we present a novel continuous-flow bioreactor loaded with β-galactosidase (β-Gal) covalently immobilized 3D-printed scaffolds for the production of lactose-free milk. 3D-printed polylactic acid (PLA) scaffolds modified by self-assembly of polyethyleneimine and sodium hyaluronate layers are rapidly branched with functional groups, followed by covalent immobilization of β-Gal using genipin as the cross-linker. The use of genipin allows efficient and stable immobilization of the enzyme (92.87 % immobilization efficiency), and the immobilized enzyme retains 90.53 % activity after 6th repeated use. Moreover, the 3D-printed scaffolds integrated into the flow reactor perturbed the fluids in the different reactors through directional channels, which improved the internal mass transfer to achieve high catalytic activity (94.20 % lactose hydrolysis efficiency). The lactose residues of milk reacted in the β-Gal flow reactor for 6 and 12 h were 1.87 g dL -1 and 0.38 g dL -1 , which fully met the requirements of the national food safety standards for low-lactose and lactose-free milk. Due to the high efficiency of enzyme immobilization and the stable catalytic activity of the reactor, it has a broad application prospect for the production of low-lactose and lactose-free milk and other biocatalytic fields.
研究领域:
食品科学
·
生物工程
·
酶技术
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DOI
高影响因子
Food & Function
·
2015
·Vol. 6
·期 10
·3291-3295
·
IF 2.791
Hui-da Wan,Yong-mei Xia
Enzymatic hydrolysis and transgalactosylation of stevioside (St) were investigated using a β-galactosidase from Sulfolobus sp. The hydrolysis yielded steviol as the main final product. Under the optimal transgalactosylation conditions, the highest conversion of stevioside was 87.3% with lactose as a donor, several galactosylated products (St-Gals) were obtained. Metal ions such as Na+, K2+, Ca2+, Ba2+, Mn2+ and Mg2+ (2 mM) did not affect the transgalactosylation activity, while Fe2+, Fe3+ and Cu2+ reduced the transgalactosylation activity of β-galactosidase to 64%, 33% and 18%, respectively.
研究领域:
生物化学
·
食品科学
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DOI
高影响因子
FOOD CHEMISTRY
·
2013
·
IF 3.334
Wei Wei,Danping Qi,Hai-zhen Zhao,Zhao-xin Lu,Fengxia Lv,Xiaomei Bie
A study of an enzymatic method for the production of galactosylglycerol is described. The effects of enzyme sources, enzyme amount, reaction temperature, reaction time, substrate ratio of glycerol to galactose, buffer content and pH on galactosylglycerol yield (mg/ml) were investigated. Under the optimum reaction conditions of β-galactosidases from Kluyveromyces lactis 240 U/ml, temperature 40 °C, time 24 h, buffer amount 60% (percent volume of buffer to that of substrates, pH 6.5), and the substrate molar ratio of 10 (glycerol16 mmol:galactose 1.6 mmol), the yield of galactosylglycerol was up to 116.47 mg/ml (galactose conversion 55.88%). The product was purified by activated charcoal and Sephadex G-15 column chromatography, up to 96%. The purified galactosylglycerol was fully characterised by MS and NMR, and identified as a mixture of (2R)- and (2S)- 3-O-β-D-galactopyranosyl-glycerol.
研究领域:
生物化学
·
酶工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Ruyun Lou,Weiting Yu,Yizhe Song,Ying Ren,Huizhen Zheng,Xin Guo,Yunfei Lin,Guoyu Pan,Xiuli Wang,Xiaojun Ma
Galactose moieties are covalently coupled with sodium alginate to enhance liver-specific functions in microcapsules owing to the specific interaction between the galactose moieties and the asialoglycoprotein receptors (ASGPRs) of hepatocytes. In this study, galactosylated alginate (L-NH 2 -OH-alginate) based microcapsules with desirable stability and a suitable 3D microenvironment are designed and fabricated for primary hepatocyte applications. The designed L-NH 2 -OH-alginate is fabricated via the application of ethylenediamine grafted lactobionic acid (L-NH 2 ) onto the hydroxyl groups of sodium alginate so that the negatively charged carboxyl groups intact in L-NH 2 -OH-alginate can effectively bond with Ca 2+ to form a stable three-dimensional gel network; a subsequent reaction with polycations forms a stable membrane of microcapsules. As a result, L-NH 2 -OH-alginate based microcapsules exhibit an excellent mechanical stability. Moreover, with a higher degree of substitution in L-NH 2 -OH-alginate (DS 0.41), the hepatocytes entrapped in L-NH 2 -OH-alginate microcapsules exhibit better viability and well-maintained liver-specific functions.
研究领域:
生物材料学
·
细胞工程
·
肝脏研究
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产品关联
DOI
PubMed
高影响因子
PROCESS BIOCHEMISTRY
·
2020
·
IF 2.952
Jiaying Zhu,Jiaqi Sun,YaJie Tang,Jingli Xie,Dongzhi Wei
A heterodimeric β-galactosidase was discovered in the novel strain Lactobacillus curieae M2011381. The gene encoding the enzyme was expressed in Escherichia coli BL21 (DE3). The specific enzyme activities of the recombinant holoenzyme (LacLM) and large subunit (LacL) measured 11.4 U/mg and 3.8 U/mg, respectively. The k cat /K m values of LacLM and LacL were 740 mM −1 s −1 and 1.40 mM −1 s −1 , respectively. LacLM showed maximum activity at pH 8.0 and 55 °C, and it could maintain its activity at a neutral pH and below 45 °C. LacLM displayed both hydrolysis and transgalactosylation activity on 200 g/L lactose. When LacLM was added to milk, the lactose was hydrolyzed after 6 h without galactooligosaccharide generation. The sequence alignment and homology modeling of the structures of the holoenzyme and subunits revealed that LacL has a catalytic domain with a catalytic dyad, Glu470 and Glu538, and small subunit LacM is a β-sheet domain with a conserved Trp294. The molecular docking of LacLM helped to illustrate the roles of both subunits in the reaction with lactose.
研究领域:
微生物学
·
酶学
·
生物化学
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Zhou Chen,Yanyin Song,Yuhan Yan,Wei Chen,Tong Ren,Aijin Ma,Siting Li,Yingmin Jia
A novel cellobiose 2-epimerase gene ( CsCEase1 ) from Clostridium sp. TW13 was successfully overexpressed. Cs CEase1, with a molecular mass of 45.0 kDa, exhibited a specific activity of 254.75 U/mg and showed optimal activity at 40 °C and pH 7.5. Using Cs CEase1, 44.30 % of lactose was converted into epilactose, yielding a production level of 26.58 g/L. An efficient purification method was developed, incorporating crystallization and β-galactosidase treatment to remove the unconverted lactose, while Saccharomyces cerevisiae was used to consume the produced glucose. Final purification with activated carbon resulted in epilactose with 98 % purity and a recovery rate of 66.47 %. Furthermore, Cs CEase1 was incubated with whey power and expired milk, achieving epilactose conversion rates of 29.65 % and 32.69 %, respectively. These findings highlight the potential of Cs CEase1 for the cost-effective and environmentally sustainable production of epilactose from dairy waste.
研究领域:
生物化学
·
食品科学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Yongmei Lyu,Fengxiang Chen,Wanjie Mao,Zhihan Ge,Yaoyao Zhang,Yue Hu,Wenbin Jin,Jinbin Liu,Jia Chen,Xiaohong Yu,Xiaoyang Zhang
Lactose intolerance has been a significant global health concern, as it is caused by the absence of lactase, leading to the inability of the human body to absorb lactose. This study investigated two genes encoding maltose O -acetyltransferase with β-galactosidase activity from Aeromonas caviae to evaluate their potential application value for lactose degradation in bovine and human milk. The two novel β-galactosidases (AcGal25: 22.0 kDa and AcGal31: 21.3 kDa) were heterologously expressed and biochemically characterized. The optimal pH of both enzymes was 8.0, and the optimal temperature of AcGal25 and AcGal31 were 45 and 42 °C, respectively. Fe 2+ and Mn 2+ significantly promoted the activity of both enzymes. The two enzymes kept over 75 % activity after incubation for 30 days at 45 °C. HPLC results showed that lactose in bovine milk was completely hydrolyzed by AcGal31 when reacted for 6 h, and about 5 % lactose in human milk was left. The docking results showed that AcGal31 has a more vital lactose-binding ability than AcGal25. LYS129 and ARG165 are highly likely catalytic sites of AcGal31. AcGal31 demonstrated excellent commercial value in making lactose-free milk.
研究领域:
生物化学
·
食品科学
·
工业酶学
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产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2018
·
IF 5.089
Shishan Fu,Song Miao,Xiaobin Ma,Tian Ding,Xingqian Ye,Donghong Liu
The stabilization of lactose in the form of amorphous (i.e. non-crystalline form) is the basic requirement to maintain the quality of relevant food and pharmaceutical products. The physiochemical properties of amorphous lactose mixed with galacto-oligosaccharide (GOS) were investigated. Water sorption , glass transition temperature, and crystallisation behaviour of lactose in the present of GOS (1:1 w/w) were measured at various water activity (0.11–0.75 a w , 25 °C) and lactose mutarotation was also evaluated. All of them were compared with the physiochemical properties of trehalose-lactose (1:1 w/w). The addition of GOS to lactose increased the hygroscopicity of the mixture, as well as slightly increased the glass transition temperature compared to lactose alone. The critical water activity (at 0.68 a w ) of lactose crystallisation was increased by the addition of GOS as compared to that of trehalose-lactose (1:1 w/w) (at 0.58 a w ) or lactose alone (at 0.44 a w ). The dramatical inhibition of lactose crystallisation with a lower crystallisation kinetic constant and the alternation of lactose crystal forms in the presence of GOS was observed as compared to the crystallisation behaviour of trehalose-lactose (1:1 w/w) and pure lactose at 0.68 and 0.75 a w , 25 °C. Without affecting its T g , the significantly delayed crystallisation of lactose in GOS-lactose mixture (1:1 w/w) was more likely due to the change of lactose mutarotation. As comparing to trehalose that is an effective inhibitor, GOS has a stronger ability to prevent lactose from crystallisation in hydrous matrices.
研究领域:
食品科学
·
药学
·
物理化学
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DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2024
·
IF 6
Shuxian Zhang,Xiaofei Wang,Xiaoxuan Fan,Keshuai Liu,Gidion Wilson,Xueqin Ma,Guoning Chen
Lactose can cause health problems in patients with lactose intolerance. β-Galactosidase is commonly used to catalyze the hydrolysis of lactose, thereby producing low-lactose or lactose-free products. However, most existing methods employ free enzymes, which significantly increases the economic cost. In this study, the polyurethane sponge (PUS) was selected as the carrier, and the cross-linked enzyme aggregates (CLEAs) were loaded onto the carrier after the sponge was modified. The reaction products were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier infrared transform spectroscopy, and simultaneous thermal analysis, respectively. The loading amount of β-galactosidase under the optimal conditions was 63 U/g support . The prepared PUS@β-galactosidase-CLEAs was successfully used for the hydrolysis of lactose in milk and could hydrolyze 228–304 μg of lactose in 30 min with good stability (RSD = 4.4%) and reusability. The method proposed in this study effectively combined the advantages of sponge and cross-linking enzyme aggregates, successfully achieving the decomposition of lactose in milk and rapid separation of the product. It is worth mentioning that this study provided a more effective and convenient industrial option for the production of lactose-free milk.
研究领域:
食品科学
·
生物工程
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产品关联
DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2022
·
IF 3.705
Shi-Wei Zhao,Qian Zhou,Neng-Bing Long,Rui-Feng Zhang
A novel polymer support was prepared by curing of epoxy resin in ethanol solution in the macropores of a melamine sponge. The produced polymer gel could uniformly deposit on the surface of melamine in either porous or nonporous morphology. The composite sponge with porous coating can be used as a large-sized and well-mass transferred support for the immobilization of β-galactosidase from Bacillus circulans through method of adsorption and crosslinking, and a column reactor was made for the preparation of N-acetyllactosamine in a sealed circulation way. The porosity and specific surface area of the support were 91.6 % and 46 m 2 /g, respectively. The loading amount and the specific activity of immobilized β-galactosidase under the optimal immobilization conditions were 41.2 mg/g support and 16.5 U/mg protein , respectively. In the biosynthesis of N-acetyllactosamine lactose and N-acetylglucosamine were used as donor and acceptor, respectively. Under optimized conditions the N-acetyllactosamine yield reached 54 % within 150 min at 50 °C. After 10 cycles, the immobilized β-galactosidase retained 70 % of the original activity.
研究领域:
生物化学
·
酶工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Lu Zhao,Youzhi Zhou,Song Qin,Panpan Qin,Jianlin Chu,Bingfang He
β-Galactosidases can catalyze the hydrolysis of lactose and the synthesis of galacto-oligosaccharides (GOS) from lactose. The catalytic activity of β-galactosidases is usually inhibited by galactose and glucose, which hampers the complete hydrolysis of lactose in food products. In this report, a β-galactosidase (denoted as BMG) from Bacillus megaterium YZ08 without the inhibition by galactose and glucose is the first to our knowledge reported. Efficient secretory expression of BMG was successfully achieved in Bacillus subtilis WB800. With the increasing of galactose and glucose, the activity of BMG dramatically enhanced. With addition of 0.6 M galactose or 1 M glucose, the initial activity to o NPG hydrolysis was increased by 2.1-fold and 4.3-fold, respectively. Moreover, the synthetic rate of galacto-oligosaccharides was enhanced by 1.1-fold and 1.9-fold with the addition of 0.7 M galactose or glucose, respectively. The GOS (278 g/L) from 600 g/L lactose by BMG were efficiently produced within 12 h, and the substrate lactose was completely used up. These results suggest that BMG shows a potential application in the food industry.
研究领域:
生物化学
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生物技术
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）