Addition Of Commercial Enzyme Research Articles

Influence of Different Salt Concentrations and Addition of Commercial Enzyme on the Chemical Characteristics of Fish Sauce from Round Scad (Decapterus maruadsi)

The effects of salt concentrations and addition of Flavourzyme on the chemical characteristics of fish sauce were studied. The fermentation mixtures were prepared by mixing fish with salt at one of two levels (25% or 30%) and Flavourzyme supplementation at 0%, 0.1%, 0.3%, and 0.5% based on fish weight, and fermented at the ambient temperature ranging from 25 to 32 °C for three months. The results showed that the fish sauces with 25% salt contained total nitrogen of 17.4 - 25.3 g/L, amino acid nitrogen of 8.1 - 13.5 g/L, and ammonia nitrogen of 1.2 - 1.9 g/L. For fish sauces with 30% salt, these contents were 16.3 - 24.2 g/L, 7.2 - 12.2 g/L and 1.1 - 1.5 g/L, respectively. The fish sauces with 25% salt had amino acid nitrogen contents of 8.1 g/L for sample without Flavourzyme and 10.9 - 13.5 g/L for samples with Flavourzyme. The higher enzyme levels gave higher yield, total nitrogen, and amino acid nitrogen contents but lower ammonia nitrogen and pH values. This study suggested that the fish sauce produced using 25% salt and 0.3% Flavourzyme was appropriate. Flavourzyme could be a potential enzyme applied to improve the chemical properties of fish sauce.

Production of the prolyl endoprotease (PEP) from Aspergillus sp. FSDE 16 by solid-state fermentation (SSF) and use for producing a gluten-free beer.

Beer is a beverage that contains gluten and cannot be consumed by people with celiac disease. In this context, the enzyme prolyl endoprotease (PEP) can be used to reduce the gluten content in beer. The present study aimed to produce the PEP from Aspergillus sp. FSDE 16 using solid-state fermentation with 5 conditions and comparing with a similar commercial enzyme produced from Aspergillus niger in the production of a gluten-free beer. The results of the performed cultures showed that during the culture, the most increased protease activity (54.46U/mL) occurred on the 4th day. In contrast, for PEP, the highest activity (0.0356U/mL) was obtained on the 3rd day of culture in condition. Regarding beer production, cell growth, pH, and total soluble solids showed similar behavior over the 7 days for beers produced without enzyme addition or with the addition of commercial enzyme and with the addition of the enzyme extract produced. The addition of the enzyme and the enzyme extract did not promote changes, and all the beers produced showed similar and satisfactory results, with acid pH between 4 and 5, total soluble solids ranging from 4.80 to 5.05, alcohol content ranging from 2.83% to 3.08%, and all beers having a dark character with deep amber and light copper color. Gluten removal was effectively using the commercial enzyme and the enzyme produced according to condition (v) reaching gluten concentrations equal to 17±5.31 and 21.19±11.28ppm, respectively. In this way, the production of the enzyme by SSF and its application in the removal of gluten in beer was efficient.

β-Glucanase Addition in Brewing Malt Produced by Reduced Time of Germination

Abstract The β-Glucans content has straight influence on the quality of malt and beer, mainly during the filtration step. Barley presenting high β-Glucan content demands longer germination time at malting. The application of commercial β-Glucanase is an alternative to accelerate the process and preserve the quality of malt. This work aimed to evaluate the effect of commercial β-Glucanase addition in malt produced within reduced germination time (64 h). Micro-malting was conducted with BRS-Caue and Elis barley cultivars at germination time 64 h and 96 h. The β-Glucanase concentration applied were 0, 25, 50 and 100 mg.kg-1. Barley, malt and wort samples were analyzed to check their physical-chemical features. Beers were produced with BRS-Caue malt and the physical-chemical and sensory attributes were analyzed. The commercial enzyme addition in BRS-Caue and Elis (64 h), at concentration 25 and 50 mg.kg-1, resulted in wort presenting proper β-Glucan content (≤ 178 mg.L-1). The beer produced with malt germinated for 64 h and added with 50 mg.kg-1 of β-glucanase was the one showing the largest number of physical-chemical and sensory parameters similar to the beer made with malt germinated for 96 h (conventional process). Commercial β-glucanase application in malt allowed accelerating the malting process without affecting the quality of the malt for beer production.

Consolidated bioprocessing for cellulosic ethanol conversion by cellulase–xylanase cell-surfaced yeast consortium

Consolidated bioprocessing (CBP) strategy was developed to construct a cell-surface displayed consortium for heterologously expressing functional lignocellulytic enzymes. The reaction system composed of two engineered yeast strains: Y5/XynII-XylA (co-displaying two types of xylanases) and Y5/EG-CBH-BGL (co-displaying three types of cellulases). The immobilization of recombinant fusion proteins and their cell-surface accessibility of were analyzed by flow cytometry and immunofluorescence. The feasibility of consolidated bioprocessing by using pretreated corn stover (CS) as substrate for direct bioconversion was further investigated, and the synergistic activity and proximity effect between cellulases and xylanases on lignocelluloses degradation were also discussed in this work. Without any commercial enzyme addition, the combined yeast consortium produced 1.61 g/L ethanol which achieved 64.7% of the theoretical ethanol yield during 144 h from steam-exploded CS. The results indicated that the assembly of cellulases and xylanases using a synthetic consortium capable of combined displaying lignocellulytic enzymes is a promising approach for simultaneous saccharification and fermentation to ethanol from lignocellulosic biomass.

Effect of malting time, mashing temperature and added commercial enzymes on extract recovery from a Nigerian malted yellow sorghum variety

Preliminary microbiological studies carried out on sorghum grains showed that the major microorganisms found were mainly bacteria and that aflatoxin-producing fungi were not found. The effect of added commercial enzyme preparations and different infusion mashing temperatures on extract yield, from sorghum malted at 30 °C, was studied. The infusion mashing method (65 °C) developed for mashing well-modified barley malt produces poor extract yields with sorghum malt. The extract yield from the sorghum malt in this study was very low with infusion mashing at 65 °C, without the addition of commercial enzyme preparations. A higher extract yield was obtained from the sorghum malt, without the commercial enzyme addition, when using infusion mashing at 85 °C. Both infusion mashing temperatures (65 and 85 °C) showed an improved extract yield over the control malt when commercial enzyme preparations were used during mashing of the sorghum malt. The added enzyme preparations resulted in a higher extract yield from the germinated sorghum when infusion mashing was performed at 65 °C over mashing at 85 °C. The use of individual commercial enzymes (α-amylase, β-glucanase, protease, xylanase, saccharifying enzyme and combinations of some hydrolytic enzyme) increased extract yields, when complemented with the enzymes that had developed in the sorghum malt. Copyright © 2016 The Institute of Brewing & Distilling

Consolidated bioprocessing of starchy substrates into ethanol by industrial Saccharomyces cerevisiae strains secreting fungal amylases.

The development of a yeast strain that converts raw starch to ethanol in one step (called Consolidated Bioprocessing, CBP) could significantly reduce the commercial costs of starch-based bioethanol. An efficient amylolytic Saccharomyces cerevisiae strain suitable for industrial bioethanol production was developed in this study. Codon-optimized variants of the Thermomyces lanuginosus glucoamylase (TLG1) and Saccharomycopsis fibuligera α-amylase (SFA1) genes were δ-integrated into two S. cerevisiae yeast with promising industrial traits, i.e., strains M2n and MEL2. The recombinant M2n[TLG1-SFA1] and MEL2[TLG1-SFA1] yeast displayed high enzyme activities on soluble and raw starch (up to 8118 and 4461 nkat/g dry cell weight, respectively) and produced about 64 g/L ethanol from 200 g/L raw corn starch in a bioreactor, corresponding to 55% of the theoretical maximum ethanol yield (g of ethanol/g of available glucose equivalent). Their starch-to-ethanol conversion efficiencies were even higher on natural sorghum and triticale substrates (62 and 73% of the theoretical yield, respectively). This is the first report of direct ethanol production from natural starchy substrates (without any pre-treatment or commercial enzyme addition) using industrial yeast strains co-secreting both a glucoamylase and α-amylase.

Ethanol production via simultaneous saccharification and fermentation of sodium hydroxide treated corn stover using Phanerochaete chrysosporium and Gloeophyllum trabeum

Ethanol was produced via the simultaneous saccharification and fermentation (SSF) of dilute sodium hydroxide treated corn stover. Saccharification was achieved by cultivating either Phanerochaete chrysosporium or Gloeophyllum trabeum on the treated stover, and fermentation was then performed by using either Saccharomyces cerevisiae or Escherichia coli K011. Ethanol production was highest on day 3 for the combination of G. trabeum and E. coli K011 at 6.68 g/100g stover, followed by the combination of P. chrysosporium and E. coli K011 at 5.00 g/100g stover. SSF with S. cerevisiae had lower ethanol yields, ranging between 2.88 g/100g stover at day 3 (P. chrysosporium treated stover) and 3.09 g/100g stover at day 4 (G. trabeum treated stover). The results indicated that mild alkaline pretreatment coupled with fungal saccharification offers a promising bioprocess for ethanol production from corn stover without the addition of commercial enzymes.

Ethanol Production from Seaweed, Enteromorpha intestinalis, by Separate Hydrolysis and Fermentation (SHF) and Simultaneous Saccharification and Fermentation (SSF) with Saccharomyces cerevisiae

Ethanol productions were performed by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes using seaweed, Enteromorpha intestinalis (sea lettuce). Pretreatment conditions were optimized by the performing thermal acid hydrolysis and enzymatic hydrolysis for the increase of ethanol yield. The pretreatment by thermal acid hydrolysis was carried out with different sulfuric acid concentrations in the range of 25 mM to 75 mM <TEX>$H_2SO_4$</TEX>, pretreatment time from 30 to 90 minutes and solid contents of seaweed powder in the range of 10~16% (w/v). Optimal pretreatment conditions were determined as 75 mM <TEX>$H_2SO_4$</TEX> and 13% (w/v) slurry at <TEX>$121^{\circ}C$</TEX> for 60 min. For the further saccharification, enzymatic hydrolysis was performed by the addition of commercial enzymes, Celluclast 1.5 L and Viscozyme L, after the neutralization. A maximum reducing sugar concentration of 40.4 g/L was obtained with 73% of theoretical yield from total carbohydrate. The ethanol concentration of 8.6 g/L of SHF process and 7.6 g/L of SSF process were obtained by the yeast, Saccharomyces cerevisiae KCTC 1126, with the inoculation cell density of 0.2 g dcw/L.

Direct and efficient ethanol production from high-yielding rice using a Saccharomyces cerevisiae strain that express amylases

Efficient ethanol producing yeast Saccharomyces cerevisiae cannot produce ethanol from raw starch directly. Thus the conventional ethanol production required expensive and complex process. In this study, we developed a direct and efficient ethanol production process from high-yielding rice harvested in Japan by using amylase expressing yeast without any pretreatment or addition of enzymes or nutrients. Ethanol productivity from high-yielding brown rice (1.1 g/L/h) was about 5-fold higher than that obtained from purified raw corn starch (0.2 g/L/h) when nutrients were added. Using an inoculum volume equivalent to 10% of the fermentation volume without any nutrient supplementation resulted in ethanol productivity and yield reaching 1.2 g/L/h and 101%, respectively, in a 24-h period. High-yielding rice was demonstrated to be a suitable feedstock for bioethanol production. In addition, our polyploid amylase-expressing yeast was sufficiently robust to produce ethanol efficiently from real biomass. This is first report of direct ethanol production on real biomass using an amylase-expressing yeast strain without any pretreatment or commercial enzyme addition.

The application of triticale variety Odyssey as the substitute for malt in wort production

The objective of this work was to investigate the possibility of triticale application as the partial substitute for malt in wort production. For wort production, two series of experiments were performed in which triticale variety Odyssey, from experimental fields, Rimski Sancevi location (Serbia), was used as the substitute for barley malt in grist with and without the addition of commercial enzyme Ultraflo Max (Novozymes, Denmark). Triticale was added in each of the carried series of experiments as the substitute for malt: 0, 10, 20, 30, 40, 50, 60, 70 and 80% in grist. Experiments were carried out on laboratory scale by the application of infusion procedure for wort production. Regarding extract content, triticale variety Odyssey could be used as the substitute for malt up to 60% without the addition of commercial enzyme Ultraflo Max. With the addition of this enzyme triticale variety Odyssey could be used as a substitute for malt up to 80%, regarding the extract content. With the increase in the content of triticale in the grist, viscosity increased. The addition of commercial enzyme Ultraflo Max significantly reduced wort viscosity. The obtained results indicate that worts produced with the addition of triticale variety Odyssey to grist yielded good analytical quality parameters.

Primary sludge floc degradation is accelerated under biosulphidogenic conditions: Enzymological aspects

The mechanism of enhanced sludge floc fracture due to the action of enzymes hydrolysing important structural components, remains a key element in our understanding of how the floc integrity in systems utilising a sulphate-reducing system is compromised. Commercial β-glucosidase and cellulase as well as proteases were added to methanogenic bioreactor and sulphidogenic bioreactor sludge and the effect of these enzymes on sludge floc size (diameter) distribution was investigated using bright field and differential interference contrast light microscopy. Cellulolytic activity of the enzymes was monitored using standard enzyme assay techniques and Bradford, Somogyi–Nelson, and total carbohydrate assays were performed. Sludge flocs present in the sulphide-rich environment of the sulphidogenic bioreactor were found to be of smaller average diameter (23 μm) than those flocs present in the methanogenic bioreactor (average diameter of 40 μm). The addition of commercially available enzymes resulted in an increased rate of matrix hydrolysis, leading to increased rates of floc fracture and smaller flocs. The presence of β-glucosidase activity and protease, naturally residing within the sludge flocs, was confirmed. The addition of commercial enzymes may be prohibitively costly on a large scale, and ways of increasing the activities of these enzymes naturally residing within the floc matrix were investigated. As the bulk of the extracellular polymeric substances (EPS) was shown to be composed of mainly polysaccharides and protein, it was proposed that, by increasing the activities of the native β-glucosidases and proteases naturally residing within the floc matrix, the process of floc hydrolysis could be enhanced. Sulphide was shown to increase the activity of these key enzymes, and we propose that this is one of the factors contributing to the accelerated rate of sludge solubilisation under sulphate-reducing conditions. It was also confirmed that this effect of sulphide occurred at the enzymatic level.