Β-galactosidase Production Research Articles

Production and characterization of β-galactosidase from the fungus Thielaviopsis ethacetica Went.

The Journal of the National Science Foundation of Sri Lanka publishes the results of research in all aspects of Science and Technology. The journal also has a website at http://www.nsf.gov.lk/. 2021 Impact Factor: 0.682The JNSF provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.

Screening and characterization of β-galactosidase activity in lactic acid bacteria for the valorization of acid whey

β-Galactosidase is an enzyme produced by some strains of lactic acid bacteria (LAB) commonly found in dairy products; however, industrial demand for these enzymes is still low. Acid whey (AW), a lactose-rich byproduct, has large output from cottage cheese and remains unexploited. The purpose of this study was to understand the production mechanism of β-galactosidase from LAB using AW as a culture medium. First, bioinformatics analysis was conducted on 15 species of LAB. Then, 24 strains were selected and inoculated in de Man, Rogosa, and Sharpe (MRS) broth and in AW medium to compare the bacterial kinetic growth and β-galactosidase production. Bacterial growth and total protein activity were measured using spectrophotometric techniques. β-Galactosidase activity was determined by 2 methods: following the hydrolysis of o-nitrophenyl-β-d-galactopyranoside and of 5-bromo-4-chloro-3-indoyl-β-d-galactopyranoside (X-gal) in tryptic soy agar plates. The relative expression of the β-galactosidase gene was performed using real-time quantitative PCR. Despite generally lower growth in AW, 18 strains showed higher β-galactosidase activity when grown in AW compared with MRS medium. The highest β-galactosidase activity in AW was in Lactobacillus helveticus strain OSU-PECh-4A, which showed almost 5 times higher activity than average. Analysis of 6 selected strains for expression of the bgal-620 gene found higher overexpression in AW than in MRS, regardless of specific β-galactosidase activity. Strains of LAB such as OSU-PECh-4A could valorize AW through the production of β-galactosidase (as an aid to lactose digestion) and production of prebiotic galactooligosaccharides.

Point-of-Care Analyte Quantification and Digital Readout via Lysate-Based Cell-Free Biosensors Interfaced with Personal Glucose Monitors.

Field-deployable diagnostics based on cell-free systems have advanced greatly, but on-site quantification of target analytes remains a challenge. Here we demonstrate that Escherichia coli lysate-based cell-free biosensors coupled to a personal glucose monitor (PGM) can enable on-site analyte quantification, with the potential for straightforward reconfigurability to diverse types of analytes. We show that analyte-responsive regulators of transcription and translation can modulate the production of the reporter enzyme β-galactosidase, which in turn converts lactose into glucose for PGM quantification. Because glycolysis is active in the lysate and would readily deplete converted glucose, we decoupled enzyme production and glucose conversion to increase the end point signal output. However, this lysate metabolism did allow for one-pot removal of glucose present in complex samples (like human serum) without confounding target quantification. Taken together, our results show that integrating lysate-based cell-free biosensors with PGMs enables accessible target detection and quantification at the point of need.

Chlorella sorokiniana cultivation in cheese whey for β-galactosidase production

Biotechnological processes with microalgae with the aim to achieve high biomass yields must choose the appropriate nutrients and physicochemical parameters, taking into account the specific characteristics of each species to determine the basic needs for its growth. In the present study, the better growth condition of Chlorella sorokiniana IPR 7104 was optimized to reach the maximum beta-galactosidase production. The cheese whey concentration (%), temperature (˚C) and pH were factors investigated and a Box-Behnken Design (BBD) approach was implemented using Statistica 7.0 software. We observed that the cultivation condition to Chlorella sorokiniana IPR 7104 was the heterotrophic, which showed the major enzymatic activity, consequently a lower residual lactose content. Under heterotrophic conditions (without light) the β-galactosidase activity increased linearly until the 8th day. Biomass production grew linearly on the 12th day. The microalgae consumed 89.6% of lactose in 3 days, showing a high capacity to metabolize this disaccharide, through β-galactosidase synthesis. The maximum β-galactosidase production by Chlorella sorokiniana IPR 7104, in heterotrophic conditions and using cheese whey as carbon source, is obtained using the following conditions: 30°C temperature, concentration of ethanol at 20% and time of 4 min.

Isolation and characterization of potential probiotic lactic acid bacteria from traditional cheese

A total of 25 traditionally procured white cheese were collected from the Samsun region in Turkey. Selected physicochemical and microbiological characteristics of the cheese were screened via classical analysis and significant differences were detected between cheese samples. In this study, twelve lactic acid bacterial isolates with high antimicrobial activity from these cheeses were selected for further analysis. Isolated strains were identified and characterized by phenotypic and genotypic methods, and their probiotic and industrial properties were studied. Nine of the isolates were identified as enterococci (4 E. durans, 3 E. faecium, 1 E. faecalis and 1 E. gallinarum). Other identified strains included 2 Lactiplantibacillus pentosus, and 1 Loigolactobacillus coryniformis subsp. torquens. A series of established in vitro tests were conducted to determine the probiotic potential of isolates. These tests include bile and gastric juice tolerance, antibiotic resistance, ability to survive at different temperatures, pH ranges, and salt concentrations, acid-producing ability, proteolytic activity, β-galactosidase production, and the ability to produce gas from glucose. The results of the study suggested that the E. faecium S1113, E. durans S104, E. durans S1121, and E. durans S202 isolates have potential use as novel probiotic strains in the food industry.

Rice straw and orange peel wastes as cheap and eco-friendly substrates: A new approach in β-galactosidase (lactase) enzyme production by the new isolate L. paracasei MK852178 to produce low-lactose yogurt for lactose-intolerant people.

Converting wastes to valuable products is the main target for many kinds of research nowadays. Wastes represent an environmental problem and getting rid of it is not easy and causes pollution. Accordingly, this study offers production of the valuable enzyme β-galactosidase using rice straw and orange peel as the main medium constituents. β-galactosidase converts lactose to glucose and galactose which are simple sugars and can be fermented easily by lactose-intolerant people who represent more than 50% of the world's population. It was produced by Lactobacillus paracasei, a series isolated from fermented milk, identified using 16S ribosomal RNA gene partial sequence and had the accession number MK852178. Plackett-Burman (PB) and Central Composite (CCD) Designs optimized the production scoring 1.683(10)6 U/ml with a difference five times higher than the non-optimized medium. The addition of 0.3 or 0.6% of β-galactosidase serves as a good fortification for manufacturing nutritional and therapeutic low-lactose yogurt with no significant differences in total protein, total solids, fat, and ash between control and all treatments. The chemical, rheological and sensory properties of the final produced yogurt were evaluated during storage periods up to 9days at 5°C. In conclusion, L. paracasei MK852178 β-galactosidase is a promising additive in manufacturing low lactose yogurt for lactose-intolerant people since it reduces the lactose content and doesn't influence the chemical and sensory properties.

Characterisation of a potential probiotic strain Paracoccus marcusii KGP and its application in whey bioremediation.

Whey, the main by-product obtained from the manufacture of cheese, which contains a very high organic load (mainly due to the lactose content), is not easily degradable and creates concern over environmental issues. Hydrolysis of lactose present in whey and conversion of whey lactose into valuable products such as bioethanol, sweet syrup, and animal feed offers the possibility of whey bioremediation. The increasing need for bioremediation in the dairy industry has compelled researchers to search for a novel source of β-galactosidase with diverse properties. In the present study, the bacterium Paracoccus marcusii KGP producing β-galactosidase was subjected to morphological, biochemical, and probiotic characterisation. The bacterial isolate was found to be non-pathogenic and resistant to low pH (3 and 4), bile salts (0.2%), salt (10%), pepsin (at pH 3), and pancreatin (at pH 8). Further characterisation revealed that the bacteria have a good auto-aggregation ability (40% at 24h), higher hydrophobicity (chloroform-60%, xylene-50%, and ethyl acetate-40%) and a broad spectrum of antibiotic susceptibility. The highest growth of P. marcusii KGP was achieved at pH 7 and 28°C, and the yeast extract, galactose, and MgSO4 were the best for the growth of the bacterial cells. The bacterium KGP was able to utilise whey as a substrate for its growth with good β-galactosidase production potential. Furthermore, the β-galactosidase extracted from the isolate KGP could hydrolyse 47% whey lactose efficiently at 50°C. The study thus reveals the potential application of β-galactosidase from P. marcusii KGP in whey bioremediation.

A New Extracellular β-Galactosidase Producing Kluyveromyces sp. PCH397 from Yak Milk and Its Applications for Lactose Hydrolysis and Prebiotics Synthesis.

The online version contains supplementary material available at 10.1007/s12088-021-00955-1.

Integrated Utilization of Dairy Whey in Probiotic β-Galactosidase Production and Enzymatic Synthesis of Galacto-Oligosaccharides

This work established an integrated utilization of dairy whey in β-galactosidase production from Lactobacillus bulgaricus and prebiotics synthesis by the probiotic enzyme. A cost-effective whey-based medium was newly developed for culturing Lactobacillus bulgaricus to produce β-galactosidase. The medium was optimized through response surface methodology (RSM) involving a series of statistical designs, such as the Plackett–Burman design, steepest ascent experiment, and central composite design. Under the optimized medium, the β-galactosidase activity of L. bulgaricus reached 2034 U/L, which was twice that produced from the traditional MRS medium. The cells of L. bulgaricus harvested from the whey-based medium were subsequently treated with lysozyme. The resulting crude enzyme was used as an efficient catalyst, which catalyzed the synthesis of the prebiotic galacto-oligosaccharides (GOS) in a high yield of 44.7% by using whey (200 g/L) as the substrate. The sugar mixture was further purified by activated charcoal adsorption, thereby yielding a high-purity level of 77.6% GOS.

Optimizing the growth-associated β-galactosidase production by probiotic <i>Lactobacillus reuteri</i> B-14171: experimental design, culture medium volume increase, and cell growth modeling

This study reports an optimized culture medium in submerged cultivation to produce β-galactosidase by Lactobacillus reuteri. Four culture medium parameters were optimized (pH, lactose, casein, and inactive beer yeast), and the effect of different volumes of the optimized culture medium on the bioprocess was evaluated regarding β-galactosidase production. Different kinetic models were applied to predict enzymatic production as a function of biomass and substrate. It is the first time that both the effect of increasing the culture medium volume and mathematical modeling on the β-galactosidase production by L. reuteri have been studied. Besides, different bioprocess parameters were calculated based on the experimental data to verify the feasibility of enzymatic production. The achieved enzymatic activity for the optimized culture medium (12.75 g L-1 lactose; 1.88 g L-1 casein; 1.65 g L-1 inactive beer yeast and pH 5.61) resulted in an increase of 4.74-fold compared to the initial activity. Three culture medium volumes (200, 800, and 3,200 mL) were evaluated, and no significant difference was observed on maximum and total productivities (Pm and Pp), as well as on the product formation yield on biomass (YP/X). The Logistic model resulted in a good fit to the experimental data for all tested volumes, and the modified Luedeking-Piret model provided a satisfactory prediction of the enzymatic activity. The optimized culture medium reported in this work is an outstanding alternative to produce β-galactosidase by L. reuteri, which is microbial growth-associated, and the production was not affected by increasing the culture medium volume.

β‐Galactosidase: From its source and applications to its recombinant form

Carbohydrate-active enzymes are a group of important enzymes playing a critical role in the degradation and synthesis of carbohydrates. Glycosidases can hydrolyze glycosides into oligosaccharides, polysaccharides, and glycoconjugates via a cost-effective approach. Lactase is an important member of β-glycosidases found in higher plants, animals, and microorganisms. β-Galactosidases can be used to degrade the milk lactose for making lactose-free milk, which is sweeter than regular milk and is suitable for lactose-intolerant people. β-Galactosidase is employed by many food industries to degrade lactose and improve the digestibility, sweetness, solubility, and flavor of dairy products. β-Galactosidase enzymes have various families and are applied in the food-processing industries such as hydrolyzed-milk products, whey, and galactooligosaccharides. Thus, this enzyme is a valuable protein which is now produced by recombinant technology. In this review, origins, structure, recombinant production, and critical modifications of β-galactosidase for improving the production process are discussed. Since β-galactosidase is a valuable enzyme in industry and health care, a study of its various aspects is important in industrial biotechnology and applied biochemistry.

Comprehensive Substrate-Based Exploration of Probiotics From Undistilled Traditional Fermented Alcoholic Beverage 'Lugri'.

Cereal-based traditional fermented beverages (TFBs) are prevalent among India’s ethnic community, and lugri is one such TFB popular among the tribal people of the Lahaul valley in North-Western Himalaya. Previous studies have reported that lugri harbors probiotics and contains amino acids and vitamins but comprehensive substrate-specific exploration of lugri for probiotic attributes is unexplored. The present study selected three substrate-based lugri (wheat, rice, and barley) to study their biochemical properties and explore potential probiotics. This study screened the best probiotic strains for antioxidant studies and the fermentative process. A biochemical analysis determined that rice-based lugri had a higher alcohol content, electric conductivity, crude protein, and lower pH than barley and wheat-based lugri. A total of 134 distinct morphotypes were screened, and 43 strains were selected based on their qualitatively superior acid and bile tolerance. Rice-based undistilled lugri harbored the most probiotics, with 22 out of 43 strains isolated. All 43 bacterial isolates exhibited properties like cell surface hydrophobicity, cell-auto aggregation, β-galactosidase, and exopolysaccharide production, supporting them as possible probiotics. Based on antibiotic susceptibility, hemolytic activity, and biofilm formation, all the bacterial strains were found to be non-pathogenic. Taxonomically, they ranged among eight distinct genera and 10 different species. Statistically, 12 isolates were found to be the most promising probiotic, and eight strains were isolated from rice-based undistilled lugri. Furthermore, the antioxidant activity of the promising isolates was tested, based on free-radical scavenging ability toward 2,2-diphenyl-1-picrylhydrazyl (4.39–16.41%) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (15.29–57.74%). The strain Lacticaseibacillus paracasei LUL:01 showed the best antioxidant activity and probiotic attributes, and hence was used for the production of fermented milk. The strain LUL:01 fermented the sterile milk within 18 h, and the viable count remained above the legal requirement of 6 log10 CFU/ml during 28 days storage at 4°C. The strain represents a suitable candidate for applying probiotic functional food formulation with several health benefits.

Production and immobilization of β-galactosidase isolated from Enterobacter aerogenes KCTC2190 by entrapment method using agar-agar organic matrix.

In the present study, Enterobacter aerogenes KCTC2190 was isolated from soil around a cattle shed area, which was capable of producing intracellular β-galactosidase. Partially purified β-galactosidase was immobilized by entrapment method in agar-agar gel matrix. Agar-agar entrapped beads were prepared by dropping the enzyme-agar solution to ice-cooled toluene-chloroform ((3:1 (v/v)). 45.88±0.11% activity of partially purified β-galactosidase was retained after immobilization (bead shape). Maximum immobilization yield was observed in the presence of 2.5% agar-agar concentration. After immobilization, optimum temperature required for the enzyme-substrate reaction was shifted from 50 to 60 °C and the optimum reaction time was shifted from 15 to 25 min. The optimum pH for both free and immobilized β-galactosidase was pH 7. Free enzyme showed lower activation energy in comparison with the immobilized one. For free as well as immobilized β-galactosidase thermal deactivation, rate constant (kd) increased with increasing temperature while the values of decimal reduction time (D-values) and half-lives (t1/2) decreased. Immobilization process increased the t1/2 and D-values of β-galactosidase while it decreased the kd. Thermostability of immobilized β-galactosidase was higher as they showed higherenthalpy (ΔΗ0) and Gibb's free energy (ΔG0)value than those of the free β-galactosidase. The negative entropy (ΔS0) of free and immobilized β-galactosidase established that both were in a more ordered state within the temperature range (50 to 70 °C) studied. Immobilized β-galactosidase was able to retain 51.65±1.61% of its initial activity after 7 batches of enzyme-substrate reaction. Immobilized β-galactosidase showed 78.09±3.69% of its initial activity even after 40 days of storage at 4 °C.

Porungo cheese whey: β-galactosidase production, characterization and lactose hydrolysis

Abstract This study evaluated the lactose hydrolysis by immobilized β-galactosidase, which was produced by Kluyveromyces marxianus using porungo cheese whey as substrate. Initially, the yeast was cultivated in porungo cheese medium at 30 °C and 200 rpm, showing a maximal β-galactosidase production of 14.19 U mL-1. The crude extract obtained was used to evaluate the enzymatic hydrolysis in lactose solution. The optimal pH and temperature of the free and immobilized enzyme was investigated, whereas the lactose hydrolysis was carried out using two enzyme solutions (total activities of 2 U and 6 U) for both forms of the biocatalyst. Ca-alginate immobilization of β-galactosidase increased optimal temperature range to 40 °C, compared to the value for the free enzyme, which was 37 °C. The optimal pH was also increased by immobilization to 7.0, from pH 6.5 observed for the free enzyme. The highest lactose hydrolysis conversion was 15.82% using 6 U of free enzyme and 13.77% for 2 U of immobilized enzyme. Although, free enzyme showed higher conversion rates in the initial reaction time, the immobilized enzyme kept operational stability throughout reaction time, suggesting the advantage of using this technology. The use of porungo cheese whey allowed to aggregate value to this agro-industrial by-product, with the concomitant production of β-galactosidase to be used in the food industry chain itself.

Screening of endogenous strong promoters of Leuconostoc citreum EFEL2700 based on transcriptome analysis and its application for food-grade production of β-galactosidase

Leuconostoc citreum is a heterofermentative lactic acid bacterium frequently found in the various fermented foods. L. citreum EFEL2700 isolated from Korean kimchi has been used as a host strain for biotechnological applications. For the use as a food-grade host to over-produce food ingredients or enzymes, strong endogenous promoters guarantying high expression levels of target genes are necessary. In this study, transcriptomic analysis of L. citreum EFEL2700 was performed using RNA-Seq and three promoters of the most highly expressed genes were selected: glyceraldehyde 3-phosphate dehydrogenase (G3PD), 6-phosphogluconate dehydrogenase (6PGD), and phosphoketolase (PPK). Thereafter, they were used as promoters to express β-galactosidase gene from Lactobacillus plantarum WCFS1 in L. citreum EFEL2700 and the levels were compared with the control promoter P710 from L. mesenteroides ATCC 8293. As results, the β-galactosidase activities of the transformants were 2.73, 0.27, 37.43, and 9.25 units/mg under the P710, G3PD, 6PGD, and PPK promoters, respectively. The expression level of endogenous promoter 6PGD was superior to the heterologous P710 promoter previously used in a Leuconostoc-Escherichia coli shuttle vector. The 6PGD developed in this study can be used as the most suitable promoter for β-galactosidase expression in L. citreum EFEL2700.

Activation of LacZ gene in Escherichia coli DH5α via α-complementation mechanism for β-galactosidase production and its biochemical characterizations

BackgroundPlasmid propagation in recombination strains such as Escherichia coli DH5α is regarded as a beneficial instrument for stable amplification of the DNA materials. Here, we show trans-conjugation of pGEM-T cloning vector (modified Promega PCR product cloning vector with tra genes, transposable element (Tn5)) and M13 sequence via α-complementation mechanism in order to activate β-d-galactosidase gene in DH5α strain (non-lactose-fermenting host). ResultsTrans-conjugation with pGEM-T allows correction of LacZ gene deletion through Tn5, and successful trans-conjugants in DH5α host cells can be able to produce active enzyme, thus described as lactose fermenting strain. The intracellular β-galactosidase was subjected to precipitation by ammonium sulfate and subsequently gel filtration, and the purified enzyme showed a molecular weight of approximately 72-kDa sodium dodecyl sulfate-polyacrylamid gel electrophoresis. The purified enzyme activity showed an optimal pH and temperature of 7.5 and 40 °C, respectively; it had a high stability within pH 6–8.5 and moderate thermal stability up to 50 °C. ConclusionTrans-conjugant of E. coli DH5α- lacZ∆M15 was successfully implemented. UV mutagenesis of the potent trans-conjugant isolate provides an improvement of the enzyme productivity. The enzymatic competitive inhibition by d-galactose and hydrolysis of lactose at ambient temperatures could make this enzyme a promising candidate for use in the dairy industry.

Microalgae Grown in Cheese Whey and β-galactosidase Production

O soro de queijo é o principal subproduto da indústria de laticínios e a alta demanda biológica e química de oxigênio (DBO e DQO) pode causar vários problemas ambientais. Estudos recentes apontam os potenciais usos biotecnológicos do soro de queijo, como o meio de fermentação, para a produção de β-galactosidase. A enzima é muito importante para hidrólise da lactose em galactose e glicose, monossacarídeos mais digeríveis pelo organismo humano. As microalgas podem produzir a β-galactosidase através de processos fermentativos. O objetivo da presente revisão é descrever sucintamente o progresso recente sobre o uso de microalgas na produção de β-galactosidase. No geral, o artigo resume o estado atual do conhecimento sobre microalgas, beta-galactosidase e soro de queijo como fonte de carbono para o crescimento de microalgas e dentro do conceito de economia circular. No entanto, ainda são necessários estudos adicionais sobre as melhores condições de cultivo de microalgas com o objetivo de produzir a enzima em questão.
 
 Palavras-chave: Indústria de lacticínio. Biotecnologia. Economia Circular. Valor Agregado.
 
 Abstract
 Cheese whey is the main by-product of dairy industry and due to high biological and chemical oxygen demands (BOD and COD) can cause several environmental problems. Recent studies have pointed the biotechnological potential uses of cheese whey such as fermentation medium to the β-galactosidase production. The enzyme is very important to breakdown the lactose into galactose and glucose, monosaccharide sugars more digestible than lactose. Microalgae can produce β-galactosidase through fermentative processes. The purpose of the current mini-review is to succinctly describe recent progress about the use of microalgae to β-galactosidase production. Overall, the paper summarizes the current state of knowledge about microalgae, beta-galactosidase and cheese whey as carbon source to growing of microalgae and within circular economy concept. However, there is still a need for further studies regarding the best microalgae cultivation conditions with the objective of producing the enzyme in question.
 
 Keywords: Dairy industry. Biotechnology. Circular Economy. Added Value.
 

Optimization by response surface methodology for production of β-galactosidase from Enterococcus faecium using recycled medium

In this study, recycled medium from three photosynthetic microorganisms (Chlorella vulgaris, Dunaliella tertiolecta and Arthrospira platensis) was evaluated for use in producing β-galactosidase, an enzyme traditionally used to degrade lactose in dairy products. Recycled medium from Chlorella vulgaris was selected to optimize culture medium to be used to produce β-galactosidase by Enterococcus faecium in submerged fermentation. Response Surface Methodology (RSM) was used to optimize the levels of the variables: temperature (30-40°C), lactose concentration (0-5%), fermentation time (12-24h), pH (6-8) and their interaction. All variables studied had a statistically significant effect on the production of β-galactosidase. The optimal conditions for producing the enzyme were achieved: temperature of 31ºC, lactose concentration of 5.34%, fermentation time of 12h and pH of 8.0. Under these conditions, the β-galactosidase activity was 29.85 U/mL which was quite close to the predicted value (30.83 U/mL). Finally, it can be concluded that recycled medium from optimized C. vulgaris supernatant may well be important for the biotechnology industry as it is an abundant low-cost source for producing β-galactosidase by Enterococcus faecium.

Production and partial purification by PEG/citrate ATPS of a β-galactosidase from the new promising isolate Cladosporium tenuissimum URM 7803

β-Galactosidase production, partial purification and characterization by a new fungal were investigated. Partial purification was performed by aqueous two-phase system (ATPS) using polyethylene glycol (PEG) molar mass, PEG concentration, citrate concentration and pH as the independent variables. Purification factor (PF), partition coefficient (K) and yield (Y) were the responses. After identification by rDNA sequencing and classification as Cladosporium tenuissimum URM 7803, this isolate achieved a maximum cell concentration and β-galactosidase activity of 0.48 g/L and 462.1 U/mL, respectively. β-Galactosidase partitioned preferentially for bottom salt-rich phase likely due to hydrophobicity and volume exclusion effect caused in the top phase by the high PEG concentration and molar mass. The highest value of PF (12.94) was obtained using 24% (w/w) PEG 8000 g/mol and 15% (w/w) citrate, while that of Y (79.76%) using 20% (w/w) PEG 400 g/mol and 25% (w/w) citrate, both at pH 6. The enzyme exhibited optimum temperature in crude and ATPS extracts in the ranges 35–50 °C and 40–55 °C, respectively, and optimum pH in the range 3.0–4.5, with a fall of enzyme activity under alkaline conditions. Some metal ions and detergents inhibited, while others stimulated enzyme activity. Finally, C. tenuissimum URM 7803 β-galactosidase showed a profile suitable for prebiotics production.

Production of β‐galactosidase by Trichoderma sp. through solid‐state fermentation targeting the recovery of galactooligosaccharides from whey cheese

Optimization of β-galactosidase production by Trichoderma sp. under solid-state fermentation using wheat bran as solid substrate through an experimental design and its application targeting the recovery of galactooligosaccharides (GOS) from whey cheese. The β-galactosidase production by Trichoderma sp. increased 2·3-fold (2·67Ug-1 of substrate) culturing the fungus at 30°C for 187h, at an inoculum of 105 spores per ml, and a 1:1·65 (w/v) ratio of wheat bran to tap water. The best enzyme activity was obtained at 55°C and pH 4·5. The catalytic activity was maintained for up to 180min incubating at 35-45°C, and above 50% at acidic or alkaline pH for up to 24h. It also presented resistance to chemical compounds. β-galactosidase catalysed the hydrolysis of the lactose and the transgalactosylation reaction leading to the production of GOS. Trichoderma sp. produced β-galactosidase with transgalactosylation activity that may be used to recover GOS, products with high added value, from whey cheese. β-galactosidases are used in different industrial sectors. Therefore, the Trichoderma β-galactosidase is a promising alternative for the production of GOS as prebiotic from the dairy effluents, contributing to the reduction in the environmental impact.