Β-mannanase Activity Research Articles

Production of mannooligosaccharides from orange peel waste with β-mannanase expressed in Trichosporonoides oedocephalis

A large quantity of orange peel waste (OPW) is generated per year, yet effective biorefinery methods are lacking. In this study, Trichosporonoides oedocephalis ATCC 16958 was employed for hydrolyzing OPW to produce soluble sugars. Glycosyl hydrolases from Paenibacillussp.LLZ1 which can hydrolyze cellulose and hemicellulose were mined and characterized, with the highest β-mannanase activity of 39.1 U/mg at pH 6.0 and 50 ℃. The enzyme was overexpressed in T. oedocephalis and the sugar production was enhanced by 16 %. The accumulated sugar contains 57 % value-added mannooligosaccharides by the hydrolysis of mannans. The process was intensified by a pretreatment combining H2O2 submergence and steam explosion to remove potential inhibitors. The mannooligosaccharides yield of 6.5 g/L was achieved in flask conversion and increased to 9.7 g/L in a 5-L fermenter. This study improved the effectiveness of orange peel waste processing, and provided a hydrolysis-based methodology for the utilization of fruit wastes.

Production and purification of high activity β-mannanase from Streptomyces rochei and enzymatic hydrolysis of sugar palm fruit for galactomannan oligosaccharide (GMOS) production

The high activity of β-mannanase produced by Streptomyces rochei was achieved by enhancing the activity using a combination of the OFAT and the CCD of RSM method.The activity of β-mannanase produced by Streptomyces rochei was obtained to be 201.63 U/mL using OFAT method. Furthermore, the CCD of RSM optimized several process parameters such as nitrogen, carbon, and (KH2PO4) concentration. The maximum β-mannanase yield was nearly 7.5 times (460 U/mL) higher than the unoptimized condition (61.09 U/mL). The purified β-mannanase had a molecular weight of approximately 35.0 kDa and showed optimal activity at a pH of 6.0 and a temperature of 60 °C. Manannase could hydrolyze galactomannan-rich mannan polymers such as sugar palm fruit and other commercial mannans to create GMOS. For further research, developing a recombinant mannanase, scaling up the production of mannanase and also the study of GMOS activity for the health industrial applications are necessary. Additionally, it is important to conduct in vivo and in vitro assays to examine the activity of GMOS for potential application in the health industry.

Purification And Characterization of Mannanase Enzyme from Lentinula edodes Isolate and Evaluation of Its Activity in Removing Blood Stains from Cotton Fabrics.

Shiitake mushroom is the Japanese common name for the genus Lentinula edodes, and Shiitake is a fungus of medicinal and industrial importance. The enzyme Mannanase was purified from the fungal culture filtrate. It included a series of steps, including precipitation with ammonium sulfate and a saturation rate of 80%, in which the specific activity reached 2 units/mg, and the enzymatic accumulation was 80%. It was followed by enzyme dialysis for a whole day, which caused an increase in the specific activity to 3 units/mg, the number of purification times reached 3 times, and the enzymatic accumulation reached 71%. It is noticed from the ion exchange step using DEAE-cellulose that the specific activity increased to 10 units/mg, the number of purification times reached 10 times, and the enzymatic accumulation reached 53%. Subsequently, the last purification step was carried out using gel filtration chromatography Sephadex G-150, in which the specific activity of the enzyme reached 24 units/mg and the number of purification times reached 24 times, with an enzymatic accumulation of 48%. The molecular weight was determined using electrophoresis in a polyacrylamide gel, and its molecular weight was 58 kilodaltons. The optimum pH for its activity was 6.5, while the pH ranged between (5.5-7) to prove its activity. The optimum temperature for enzyme activity was 60°C, while the thermal stability was between (20-80) °C. Keywords: Lentinula edodes, β-mannanase activity, purifi-cation, DEAE-Sephadex A-150, Characterization, removing and ability of detergents to clean clothes.

Engineered Alcaligenes sp. by chemical mutagen produces thermostable and acido-alkalophilic endo-1,4-β-mannanases for improved industrial biocatalyst

This study reported physicochemical properties of purified endo-1,4-β-mannanase from the wild type, Alcaligenes sp. and its most promising chemical mutant. The crude enzymes from fermentation of wild and mutant bacteria were purified by ammonium sulfate precipitation, ion exchange and gel-filtration chromatography followed by an investigation of the physicochemical properties of purified wild and mutant enzymes. β-mannanase from wild and mutant Alcaligenes sp. exhibited 1.75 and 1.6 purification-folds with percentage recoveries of 2.6 and 2.5% and molecular weights of 61.6 and 80 kDa respectively. The wild and mutant β-mannanase were most active at 40 and 50 °C with optimum pH 6.0 for both and were thermostable with very high percentage activity but the wild-type β-mannanase showed better stability over a broad pH activity. The β-mannanase activity from the parent strain was stimulated in the presence of Mn2+, Co2+, Zn2+, Mg2+ and Na+. Vmax and Km for the wild type and its mutant were found to be 0.747 U//mL/min and 5.2 × 10−4 mg/mL, and 0.247 U/mL/min and 2.47 × 10−4 mg/mL, respectively. Changes that occurred in the nucleotide sequences of the most improved mutant may be attributed to its thermo-stability, thermo-tolerant and high substrate affinity- desired properties for improved bioprocesses.

Characterization of a novel GH26 β-mannanase from Paenibacillus polymyxa and its application in the production of mannooligosaccharides

A novel glycoside hydrolase family 26 β-mannanase gene ppman26a was cloned from Paenibacillus polymyxa KF-1. The full-length enzyme PpMan26A and its truncated products CBM35pp (aa 35–328) and PpMan26A-Δ205 (aa 206–656) were overexpressed in Escherichia coli. PpMan26A hydrolyzed locust bean gum, guar gum, konjac gum and ivory nut mannan, with the highest specific activity toward konjac gum. The Km and kcat values for konjac gum were 2.13 mg/mL and 416.66 s–1, respectively. The oligosaccharides fraction obtained from the hydrolysis of konjac gum by PpMan26A was analyzed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometer (MALDI-TOF-MS). The degradation products were mainly mannooligosaccharides with a degree of polymerization of 3–8. CBM35pp exerted strong binding activity toward mannans but without β-mannanase activity. PpMan26A-Δ205, with the deletion of the N-terminal CBM domain, showed lower substrate binding capacity, resulting in reduced enzymatic activity and thermostability. This study complements our understanding of GH26 β-mannanases and expands the potential industrial application of PpMan26A.

Keratinase, Caseinolitic, Cellulase and β-Mananase Activities of Bacteria Isolated from the Black Sea

For a long time, the main interest in the marine environment, considered extreme, was the isolation and identification of natural products with biological properties, and for that, numerous organisms and chemical structures have been studied. Thus, marine bacteria isolated from various substrates, such as sediments, seawater, and mangrove detritus, are producers of enzymes with different activities, i.e., amylase, cellulase, alginate lyase, chitinase, glucosidase, inulinase, keratinase, ligninase, xylanase, and others. Nowadays, researchers are also focusing on the enzymes produced in the marine environment that can present special properties. Therefore, the aim of this study was to investigate the ability of marine strains of microorganisms to exhibit cellulase, β-mannanase, keratinase, and caseinolytic activities. Methods. Enzymatic activities were studied in the culture liquid supernatant. To determine β-mannanase and cellulase activities, guar gum galactomannan and Na-carboxymethylcellulose respectively were used as substrates. Casein and crushed defatted feathers served as substrates for the determination of proteolytic activity. Results. Growing 10 cultures of microorganisms on a nutrient medium containing chicken feathers as the sole source of carbon and nitrogen (nutrient medium 1) did not give positive results. When using medium 2, active growth was observed in four of the studied strains (51, 52, 54, 247) in the supernatant of culture liquid (CLS), the activity of which both to keratin (6.0—16.0 U/mL) and casein (0.025—0.33 U/mL) was found. In the CLS of only six of the 10 studied cultures (7, 20, 51, 52, 50, 247), cellulase and β-mannanase activities were observed. The highest cellulase activity was found in culture 20 (1.8 U/mL). The activity of culture 7 was somewhat lower (1.0 U/mL). An insignificant activity was noted in cultures 54 (0.06 U/mL), 56, and 50 (0.05 U/mL). Trace levels of activity were observed in culture 247. Conclusions. Strains 7, 20, 247, and 51, for the first time isolated from the Black Sea, are promising for further studies as producers of cellulase, β-mannanase, keratinase, and caseinolytic enzymes.

Enhanced extracellular β-mannanase production by overexpressing PrsA lipoprotein in Bacillus subtilis and optimizing culture conditions.

In this study, first, β-mannanase gene man derived from Bacillus amyloliquefaciens CGMCC1.857 was cloned and expressed in Bacillus subtilis 168 to generate B. subtilis M1. However, the extracellular β-mannanase activity of B. subtilis M1 was not very high. To further increase extracellular β-mannanase extracytoplasmic molecular chaperone, PrsA lipoprotein was tandem expressed with man gene in B. subtilis 168 to yield B. subtilis M2. The secretion of β-mannanase of B. subtilis M2 was enhanced by 15.4%, compared with the control B. subtilis M1. Subsequently, process optimization strategies were also developed to enhance β-mannanase production by B. subtilis 168 M2. It was noted that the optimal temperature for β-mannanase production (25°C) was different from the optimal growth temperature (37°C) for B. subtilis. Based on these findings, a two-stage temperature control strategy was proposed where the bacterial culture was maintained at 37°C for the first 12 h to obtain a high rate of cell growth, followed by lowering the temperature to 25°C to enhance β-mannanase production. Using this strategy, the extracellular β-mannanase activity reached 5016 ± 167 U/ml at about 36 h, which was 19.1% greater than the best result obtained using a constant temperature (25°C). The result of this study showed that PrsA lipoprotein overexpression and two-stage temperature control strategy were more efficient for β-mannanase fermentation in B. subtilis.

A novel neutral thermophilic β-mannanase from Malbranchea cinnamomea for controllable production of partially hydrolyzed konjac powder.

Partially hydrolyzed konjac powder (PHKP) can be used to increase the daily intake of dietary fibers of consumers. To produce PHKP by enzymatic hydrolysis, a novel β-mannanase gene (McMan5B) from Malbranchea cinnamomea was expressed in Pichia pastoris. It showed a low identity of less than 52% with other GH family 5 β-mannanases. Through high cell density fermentation, the highest β-mannanase activity of 42200 U mL-1 was obtained. McMan5B showed the maximal activity at pH 7.5 and 75°C, respectively. It exhibited excellent pH stability and thermostability. Due to the different residues (Phe214, Pro253, and His328) in catalytic groove and the change of β2-α2 loop, McMan5B showed unique hydrolysis property as compared to other β-mannanases. The enzyme was employed to hydrolyze konjac powder for controllable production of PHKP with a weight-average molecular weight of 22000Da (average degree of polymerization 136). Furthermore, the influence of PHKP (1.0%-4.0%) on the qualities of steamed bread was evaluated. The steamed bread adding 3.0% PHKP had the maximum specific volume and the minimum hardness, which showed 11.0% increment and 25.4% decrement as compared to the control, respectively. Thus, a suitable β-mannanase for PHKP controllable production and a fiber supplement for steamed bread preparation were provided in this study. KEY POINTS: • A novel β-mannanase gene (McMan5B) was cloned from Malbranchea cinnamomea and expressed in Pichia pastoris at high level. • McMan5B hydrolyzed konjac powder to yield partially hydrolyzed konjac powder (PHKP) instead of manno-oligosaccharides. • PHKP showed more positive effect on the quality of steamed bread than many other dietary fibers including konjac powder.

The response surface optimization of β-mannanase produced by Weissella cibaria F1 and its potential in juice clarification

A β-mannanase-producing lactic acid bacteria (LAB) was identified as Weissella cibaria F1 according to physiological and biochemical properties, morphological observations, partial sequence of 16S rRNA gene and API 50 CHL test. In order to improve the yield of β-mannanase, the response surface methodology (RSM) was originally used to optimize the fermentation conditions. The optimization results showed that when the konjac powder, glucose, and initial pH were 9.46 g/L, 14.47 g/L and 5.67, respectively, the β-mannanase activity increased to 38.81 ± 0.33 U/mL, which was 1.33 times compared to initial yield (29.28 ± 0.26 U/mL). This result was also supported by larger clearance on the konjac powder-MRS agar plate through Congo Red dyeing. The W. cibaria F1 β-mannanase could improve the clarity of five fruits juice, i.e., apple, orange, peach, persimmon and blue honeysuckle. Among these, peach juice was the most obvious, clarity increasing by 12.8%. These results collectively indicated that W. cibaria F1 β-mannanase had an applicable potential in food-level fields.

Enhanced β-mannanase production by Bacillus licheniformis by optimizing carbon source and feeding regimes

Bacillus licheniformis HDYM-04 was isolated in flax retting water and showed β-mannanase activity. Carbon sources for β-mannanase production, as well as the fermentation conditions and feeding strategy, were optimized in shake flasks. When glucose or konjac powder was used as the carbon source, the β-mannanase activity was 288.13 ± 21.59 U/mL and 696.35 ± 23.47 U/mL at 24 h, respectively, which was approximately 4.4- to 10.68-fold higher than the values obtained with wheat powder. When 0.5% (w/v) glucose and 1% (w/v) konjac powder were added together, maximum enzyme activities of 789.07 ± 25.82 U/mL were obtained, an increase of 13.35% compared to the unoptimized cultures with only 1% (w/v) konjac powder. The enzyme activity decreased in the presence of 1% (w/v) konjac powder, but the highest enzyme activity was 1,533.26 ± 33.74 U/mL, a 1.2-fold increase compared with that in nonoptimized cultures; when 0.5% (w/v) glucose was used, the highest enzyme activity was 966.53 ± 27.84 U/mL, an increase in β-mannanase activity of 38.79% compared with control cultures. In this study, by optimizing fed-batch fermentation conditions, the yield of β-mannanase produced by HDYM-04 was increased, laying the foundation for the industrial application and further research of B. licheniformis HDYM-04.

Partial purification and application of β-mannanase for the preparation of low molecular weight galacto and glucomannan

The newly isolated Streptomyces sp. RDA1496 produced high activity of β-mannanase (415.96 IU/mL) when grown on optimized medium conditions. The produced enzyme was purified to partial homogeneity by ammonium sulphate precipitation followed by gel filtration. The β-mannanase was purified 5.12 fold to homogeneity with a specificity of 1118.79 IU/mg. The highly active fraction of β-mannanase from gel filtration, appeared as a protein band on SDS-PAGE gel with a molecular mass of 63.0 ± 2.0 kDa. β-mannanase was applied to prepare low molecular weight guar gum and konjac glucomannan by enzymatic de-polymerization. Gaur gum and konjac glucomannan (1.0% w/v) were hydrolyzed using the dialyzed β-mannanase, 3.0 mg/g of substrate for 24h. Molecular weight of hydrolyzed guar gum and konjac glucomannan were reduced to 40.73 kDa and 44.72 kDa. FTIR spectra of hydrolyzed mannan varied by different intensities of peaks compared to native mannan substrate and observed in vibrational area of O-H associated chemical group, –CH stretching of the –CH2 and –CH3 groups, and highly coupled C-C-O, C-OH and C-O-C of polymer backbone. Mannan substrates with lower molecular weight have great importance in nutrition and health industries, results indicate the hydrolyzed mannan substrates can be utilized as nutritional product for food industries.

Biochemical and structural characterization of a novel thermophilic and acidophilic β-mannanase from Aspergillus calidoustus

β-Mannanases hydrolyze lignocellulosic biomass with the release of mannan oligosaccharides, which are considered as renewable resource in higher plants. Here, we cloned, expressed and characterized a novel endo-β-mannanase (ManAC) from Aspergillus calidoustus. Homology alignment analysis indicated that ManAC belonged to glycosyl hydrolase (GH) 5 family members. The analysis of structural homologous model revealed that five residues, Arg116, Asn231, His305, Tyr307, and Trp370, constituted the active site of ManAC. Glu232 and Glu340, proton donor and nucleophile, formed the catalytic residues of ManAC. The recombinant ManAC exhibited maximal activity at pH 2.5 and 70 °C, and it was acid tolerant at a pH range of 2.0–6.0 and thermostable under 60 °C. Meanwhile, the activity of ManAC was not significantly affected by various metal ions, except for Mg2+ and Ag2+. The recombinant ManAC exhibited the highest β-mannanase activity towards locust bean gum (669.7 U/mg) with the Km and Vmax values of 3.4 mg/mL and 982.4 μmol/min/mg, respectively. These thermophilic and acidophilicc characteristics is better than most extreme β-mannanase. As the first reported mannanse from Aspergillus calidoustus (ManAC), these excellent properties of ManAC strongly promote the synthesis of mannooligosaccharides which have potential for food and feed industrial applications.

Thermophilic Fungi with Glucosidase and Proteolytic Activities

The directed search for extremophilic producers in order to obtain hydrolytic enzymes with increased thermal stability has an unconditional practical potential for use in the food and feed industry to improve the quality of the final product. The aim of the work was to study the ability of collection strains of thermophilic fungi to show α-L-rhamnosidase, α-galactosidase, cellulase, β-mannanase, keratinase and caseinolytic activity. Methods. Micromycetes were grown under submerged conditions in test tubes at 42°C for 8–14 days. Enzymatic activities were studied in the culture liquid supernatant. p-Nitrophenyl-α-D-galactopyranoside, naringin, guar gum galactomannan and Na-carboxymethylcellulose were used as substrates to determine α-galactosidase, α-L-rhamnosidase, β-mannanase and cellulase activities, respectively. Casein and crushed defatted feathers were served as substrates for the determination of proteolytic activity. Results. The enzymatic activity of 50 strains of micromycetes belonging to 17 species was investigated. The studied group showed high activity: 94% of the strains had at least one, 34% – two, 26% – from three to five enzyme activities. The most active keratinase producers were Thielavia terrestris 1920 and 62, Rhizomucor tauricus 1909, Chrysosporium thermophilum 2050, Thermoascus thermophilus 92 and Thermoascus aurantiаcus 2052 (10–26 U/mL). The highest α-L-rhamnosidase activity was observed in T. terrestris 62 (0.35 U/mL), and carboxymethylcellulase activity −in Thermomyces lanuginosus 2046. Six strains showed α-galactosidase (0.05–0.2 U/mL) and four strains − β-mannanase (5–130 U/mL) activity. Conclusions. As a result new strains producing proteolytic and glycolytic enzymes were isolated among thermophilic micromycetes. Soil thermophilic micromycetes can be used as producers of proteolytic and glycolytic enzymes. Of particular interest are the cultures of Acremonium thermophilum 1963, Corynascus thermophilum 2050, C. sepedonium 1899 and 65068, T. thermophilus 1946, which are capable of producing complexes of proteases and glycosidases in the culture liquid. This indicates that these strains are promising for use as destructors in various technologies processing of complex raw materials.

Production of mannooligosaccharides producing β-Mannanase by newly isolated Penicillium aculeatum APS1 using oil seed residues under solid state fermentation

The present investigation was focused on the production of extracellular β-mannanase from newly isolated Penicillium aculeatum APS1 using palm kernel cake and soyabean meal which are the residual by-products of oil extraction industry, under solid state fermentation. On supplementing palm kernel cake with 20% soyabean meal, yield of β-mannanase production was reached to 2807 U/g. Response surface methodology was used for statistical optimization of β-mannanase production. Two independent variables, namely moisture level and incubation time, were found to be significantly contributing for the production process. Under optimized condition of moisture level (52.25%) and incubation time (130 h), the yield of β-mannanase was improved by 1.6 fold and maximum activity of β-mannanase was 4696 U/g. The optimum temperature and pH for crude β-mannanase were 65 °C and 6.0, respectively. Crude and partially purified β-mannanase was found to be effective in release of mannooligosachharides by hydrolysis of mannan rich substrates viz. locust bean gum, guar gum and konjac glucomannan. Qualitative and quantitative analysis of MOS was carried out by TLC and ion chromatography. β-Mannanase from Penicillium aculeatum APS1 was found to have properties suitable for applications in feed/food industry.

The Increase of Incomplete Degradation Products of Galactomannan Production by Synergetic Hydrolysis of β-Mannanase and α-Galactosidase

An integrated process to increase the yield of incomplete degradation products of galactomannan (GalM) especially for galactomanno-oligosaccharides (GalMOS) was suggested. Trichoderma reesei employed Avicel or GalMOS as a carbon source to produce β-mannanase or α-galactosidase independently, with a result of 3.78 ± 0.12U/mL of β-mannanase activity and 2.45 ± 0.06U/mL of α-galactosidase activity which were obtained, respectively. GalM in Sesbania seed was hydrolyzed simultaneously by a mixture of crude enzyme with β-mannanase and α-galactosidase at a dosage of 20U/g GalM and 15U/g GalM, respectively; the yields of incomplete degradation products of GalM (IDP-GalM) and GalMOS were 78.84% ± 3.14% and 30.94% ± 0.38%, respectively, which was beneficial to improve the biological activity of the incomplete degradation products. The role of α-galactosidase addition in mixture enzymes is to remove the galactose substituents from mannan backbone of GalM and alleviate the steric hindrance of β-mannanase hydrolysis.

Enhancement of β-Mannanase Production by Bacillus subtilis ATCC11774 through Optimization of Medium Composition

Palm kernel cake (PKC) has been largely produced in Malaysia as one of the cheap and abundant agro-waste by-products from the palm oil industry and it contains high fiber (mannan) content. The present study aimed to produce β-mannanase by Bacillus subtilis ATCC11774 via optimization of the medium composition using palm kernel cake as substrate in semi-solid fermentation. The fermentation nutrients such as PKC, peptone, yeast extract, sodium chloride, magnesium sulphate (MgSO2), initial culture pH and temperature were screened using a Plackett-Burman design. The three most significant factors identified, PKC, peptone and NaCl, were further optimized using central composite design (CCD), a response surface methodology (RSM) approach, where yeast extract and MgSO2 were fixed as a constant factor. The maximum β-mannanase activity predicted by CCD under the optimum medium composition of 16.50 g/L PKC, 19.59 g/L peptone, 3.00 g/L yeast extract, 2.72 g/L NaCl and 0.2 g/L MgSO2 was 799 U/mL. The validated β-mannanase activity was 805.12 U/mL, which was close to the predicted β-mannanas activity. As a comparison, commercial media such as nutrient broth, M9 and Luria bertani were used for the production of β-mannanase with activities achieved at 204.16 ± 9.21 U/mL, 50.32 U/mL and 88.90 U/mL, respectively. The optimized PKC fermentation medium was four times higher than nutrient broth. Hence, it could be a potential fermentation substrate for the production of β-mannanase activity by Bacillus subtilis ATCC11774.

Solid‐state fermentation for the production of a recombinant β‐mannanase from Aspergillus fumigatus expressed in Aspergillus sojae grown on renewable resources

In this study, not only beta (β)-mannanase fabrication by recombinant Aspergillus sojae AsT3 in solid-state fermentation (SSF), but also the mannooligosaccharide (MOS) production was investigated. Barley husk, wheat bran, rye bran, oat husk, and spent coffee grounds were used as substrates. Plackett–Burman design was used to optimize SSF conditions (temperature, time, inoculation rate, and pH) based on enzyme activity and MOS results. While the highest β-mannanase activity was found to be 983.53 U/mg in rye bran samples, it was found to be 582.59 U/mg, 55.59 U/mg, and 413.50 U/mg for the barley husk, wheat bran, and oat husk, respectively. The highest enzyme activity and MOS production were found to be 255.82 U/mg and 1,079.785 ppm with 7% inoculation rate, 30°C, 7 days and pH 7. Results showed that SSF is suitable for β-mannanase and MOS production due to the evaluation of wastes, lower energy requirement, and suitable environment for growth. Practical applications Evaluation of all kinds of agricultural products and waste is an economical alternative source for biotechnological applications. The β-mannanase enzyme is widely used in many fields, from the coffee industry to the paper industry, from cleaning products to animal feed production. Mannooligosaccharides (MOS) are water-soluble dietary fibers and are not digested by humans. Members of this group are used by the intestinal microflora as nutrients and create useful substances for human health. When mannans are partially disintegrated by the enzyme β-mannanase, MOS that can be used as a substrate by microorganisms is produced. Therefore, the production of MOSs is one of the usage areas of the β-mannanase enzyme. In this study, β-mannanase production was carried out by using the SSF process. This process was successful to produce the enzyme and MOS. Besides, as no pretreatment is made to the carbon sources used in enzyme production, time and energy are saved.

A novel strategy to maintain the long-term viscosity stability of konjac glucomannan hydrosol by using zinc ion

The viscosity of konjac glucomannan (KGM) hydrosol dropped sharply after a period of approximately 12 h. This is a well-known problem which producers are trying to solve. Several salts were added to KGM hydrosols to attempt to improve the long-term viscosity stability of KGM hydrosol. Compared with native KGM hydrosol and KGM hydrosol with Ca2+ and Mg2+, the initial apparent viscosity of KGM hydrosol with Zn2+, in the form of zinc chloride was higher, and the long-term viscosity stability was also significantly increased. This was attributed to Zn2+ preventing the degradation of KGM induced by microbial growth. Bacillus and Paenibacillus were “culprits” in the viscosity reduction of KGM hydrosol. Zn2+ maintained the long-term viscosity stability of the hydrosol by inhibiting microbial growth and enzyme activity of β-mannanase. Zinc sulfate, zinc acetate, and zinc gluconate being edible salts were also used as a source of zinc ions and showed a similar long-term stabilization effect on the viscosity of the KGM hydrosol. These provided a realistic strategy to replace non-edible additives with edible zinc salts for food industry applications.

Enhancing β-mannanase production by controlling fungal morphology in the bioreactor with microparticle addition

Beta (β)-mannanase is an industrial enzyme that has a wide range of uses in industry. Chemically, β-mannanase mainly influences the β-1,4-mannose linkages of galactomannans. Many microbes, particularly Aspergillus species, can be utilized to produce mannanases. On the other hand, excessive filamentous clumps of Aspergillus species in bioreactors are difficult to control. Therefore, this study sought to limit the clumps resulted from the excessive fungal growth by adding microparticles into the fermentation medium. Fed-batch fermentations were performed with and without microparticles (control). As a microparticle agent, aluminum oxide (Al2O3) and talc (Mg3Si4O10(OH)2)) were evaluated as to their effect on fermentation performance. The highest β-mannanase activities were 744.35 and 356.79 U/mL for 5 g/L of Al2O3 and talc, which were 14.16- and 6.80-fold greater, respectively than in the control fermentation. Most of the treatments improved the performance of the fermentation process as the microparticles appeared to disturb the initial phase of spore aggregation. The most effective microparticle type and concentration for production of β-mannanase in a stirred tank bioreactor with a glucose-based medium were determined to be 5 g/L of Al2O3. These results indicate that the use of microparticles improve β-mannanase fermentation conditions by controlling excessive fungal growth.

The production of β-mannanase from Kitasatospora sp. strain using submerged fermentation: Purification, characterization and its potential in mannooligosaccharides production

Abstract Actinomycetes have been identified as one of the most diverse groups of microorganisms that play a vital role in the production of enzymes and nutraceuticals. In addition, prior studies on the wild type strain of Kitasatospora sp. emphasized on its ability to exhibit high β-mannanase activity. This study aimed to purify, characterize and evaluate the potential of this strain in the production of mannooligosaccharides using mannan polymer. The enzyme was produced by submerged fermentation of a medium contains locus bean gum as a carbon source. The crude mannanase was subjected to polyethylene glycol precipitation and ion exchange chromatography. The completion of the purification process was confirmed by SDS-PAGE and purified of enzyme characterization were investigated, analysis hydrolysis product was conducted by TLC. The enzymes exhibited the activity of 37.0 U/mL. A purification factor of 1.4-fold was achieved with specific activity of 6.3 U/mg. An increase of activity was recorded from 15.0 U/mL and 4.4 U/mL to 19.3 U/mL and 6.3 U/mL. In addition, the total protein decreased from 338.5 mg/mL to 45.7 mg/mL. The purified β-mannanase has the molecular weight was approximately 37.0 kDa with optimal activity at pH 6.0 and 60 °C and relatively stability at a pH variety of 6.0–9.0, retaining > 90% activity. This product was capable of hydrolysing various mannan polymers (porang potato, palm sugar fruit, coconut cake, palm cernel cake) and other commercial mannan (LBG, β-mannan, konjac, ivory nut), subsequently producing various sizes of mannoligosaccharides and mannose potential for food and feed industry.