Showing papers on "Solid-state fermentation published in 2015"

Role of Fermentation in Improving Nutritional Quality of Soybean Meal - A Review.

Abstract: Soybean meal (SBM), a commonly used protein source for animal feed, contains anti-nutritional factors such as trypsin inhibitor, phytate, oligosaccharides among others, which limit its utilization. Microbial fermentation using bacteria or fungi has the capability to improve nutritional value of SBM by altering the native composition. Both submerged and solid state fermentation processes can be used for this purpose. Bacterial and fungal fermentations result in degradation of various anti-nutritional factors, an increase in amount of small-sized peptides and improved content of both essential and non-essential amino acids. However, the resulting fermented products vary in levels of nutritional components as the two species used for fermentation differ in their metabolic activities. Compared to SBM, feeding non-ruminants with fermented SBM has several beneficial effects including increased average daily gain, improved growth performance, better protein digestibility, decreased immunological reactivity and undesirable morphological changes like absence of granulated pinocytotic vacuoles.

Solid State Fermentation

Abstract: Cheese is a solid state fermentation and, in smear cheeses, the surface microflora a biofilm. Both these modes of growth have been the subject of increasing interest and renewed research. Looking at cheese from these perspectives may offer new tools and new insights. The cheese matrix is a solid state fermentation but it differs from many of the new solid state fermentations which are being developed, often aerobic fungal processes, but it shares many of the same challenges in the measurement of system parameters and spatial heterogeneity. The importance of water availability (aw) and temperature as controlling factors on both the organisms capable of growth and their performance are implicit in the cheese-making process but perhaps not as explicitly controlled and manipulated as in solid state fermentation processes. The study of biofilms is important in pathogenesis, fouling and environmental microbiology and, unlike in the laboratory and many industrial processes, most microorganisms grow in biofilms rather than as planktonic growth in suspended liquid culture. Liquid culture lends itself to sampling and the measurement of the average properties of a population whereas cells in biofilms are spatially heterogeneous and form phenotypically differentiated subpopulations in which it is challenging to measure the properties of individual cells dynamic across spatial and temporal timescales. New technological approaches in this area are making these studies tractable and throwing up surprising complexity and sophistication relevant to understanding the behaviour of microorganism in and on cheese.

From Wastes to High Value Added Products: Novel Aspects of SSF in the Production of Enzymes

Abstract: Solid-state fermentation (SSF), a process that occurs in the absence or near absence of water, has been used for the production of various high value added products such as enzymes and other organic components. This paper reviews the recent studies reported on the use of SSF for the production of enzymes: lipases, proteases, cellulases, hemicellulases, ligninases, glucoamylases, pectinases, and inulinases. The microorganisms used for fermentation are mostly fungi, and substrates are waste materials from the agriculture and food industry. This shows the advantages of SSF from an economical and environmental viewpoint. The paper provides an update on several issues, viz. wastes, microorganisms, and issues of scaling up and controlling the process of fermentation in solid state.

Solid state fermentation (SSF)-derived cellulase for saccharification of the green seaweed Ulva for bioethanol production

Abstract: Cellulase produced from the marine fungus Cladosporium sphaerospermum through solid state fermentation (SSF) was investigated for its saccharification potential of seaweed biomass using the common green seaweed Ulva fasciata . The seaweed substrate, containing inoculated fungus with 60% moisture content, cultured at 25 °C and pH 4 for four days, showed optimum enzyme production. The enzyme, assayed for carboxymethyl cellulase and filter paper assay, showed an activity of 10.20 ± 0.40 U/g and 9.60 ± 0.64 U/g on a dry weight basis, respectively. Further, ionic liquid tolerance of the enzyme was studied in the presence of 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium trifluoromethanesulfonate and 1-butyl-1-methylpyrrolidinium trifluromethanesulfonate. At 10% v/v concentration, the enzyme retained 72.17 to 85.04% activity in all the ionic liquids. The pre-incubation of enzyme in the same ionic liquids for 24 h, the activity got slightly enhanced and ranged between 73.80 and 93.70%. The hydrolysis of U. fasciata feedstock with enzyme (10 U/g) for 24 h at 40 °C and pH 4 gave maximum yield of sugar 112 ± 10 mg/g dry weight. On fermentation, an ethanol yield of 0.47 g/g reducing sugar was obtained, corresponding to 93.81% conversion efficiency. These findings indicate that cellulase produced from a marine fungus can be employed for saccharification of cellulosic feedstock for the production of renewable biofuels from marine macroalgal feedstock. Since bioethanol yields obtained compare very favorably with those from land crops, the strategy employed in this study warrants further exploration.

Study of water dynamics in the soaking, steaming, and solid-state fermentation of glutinous rice by LF-NMR: a novel monitoring approach.

Abstract: Solid-state fermentation (SSF) of starchy grain is a traditional technique for food and alcoholic beverage production in East Asia. In the present study, low-field nuclear magnetic resonance (LF-NMR) was introduced for the elucidation of water dynamics and microstructure alternations during the soaking, steaming, and SSF of glutinous rice as a rapid real-time monitoring method. Three different proton fractions with different mobilities were identified based on the degree of interaction between biopolymers and water. Soaking and steaming significantly changed the proton distribution of the sample. The different phases of SSF were reflected by the T2 parameters. In addition, the variations in the T2 parameters were explained by the microstructure changes of rice induced by SSF. The fermentation time and T2 parameters were sigmoidally correlated. Thus, LF-NMR may be an effective real-time monitoring method for SSF in starch systems.

Thermophilic fungi as new sources for production of cellulases and xylanases with potential use in sugarcane bagasse saccharification.

Abstract: AIMS To obtain new cellulases and xylanases from thermophilic fungi; evaluate their potential for sugarcane bagasse saccharification. METHODS AND RESULTS Thirty-two heat-tolerant fungi were isolated from the environment, identified (morphological/molecular tools) and the production of the enzymes was evaluated by solid state fermentation using lignocellulosic materials as substrates. Myceliophthora thermophila JCP 1-4 was the best producer of endoglucanase (357·51 U g(-1) ), β-glucosidase (45·42 U g(-1) ), xylanase (931·11 U g(-1) ) and avicelase (3·58 U g(-1) ). These enzymes were most active at 55-70°C and stable at 30-60°C. Using crude enzymatic extract from M. thermophila JCP 1-4 to saccharify sugarcane bagasse pretreated with microwaves and glycerol, glucose and xylose yields obtained were 15·6 and 35·13% (2·2 and 1·95 g l(-1) ), respectively. CONCLUSIONS All isolated fungi have potential to produce the enzymes; M. thermophila JCP 1-4 enzymatic extract have potential to be better explored in saccharification experiments. Pretreatment improved enzymatic saccharification, as sugar yields were much higher than those obtained from in natura bagasse. SIGNIFICANCE AND IMPACT OF THE STUDY Myceliophthora thermophila JCP 1-4 produces avicelase (not commonly found among fungi; important to hydrolyse crystalline cellulose) and a β-glucosidase resistant to glucose inhibition, interesting characteristics for saccharification experiments.

Solid state fermentation of rapeseed cake with Aspergillus niger for degrading glucosinolates and upgrading nutritional value

Abstract: Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances, such as glucosinolates (Gls), phytic acid, tannins etc. In the present study, a solid state fermentation (SSF) using Aspergillus niger was carried out with the purpose of degrading glucosinolates and improving the nutritional quality of rapeseed cake (RSC). The effects of medium composition and incubation conditions on the Gls content in fermented rapeseed cake (FRSC) were investigated, and chemical composition and amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined. After 72 h of incubation at 34°C, a 76.89% decrease in Gls of RSC was obtained in solid medium containing 70% RSC, 30% wheat bran at optimal moisture content 60% (w/w). Compared to unfermented RSC, trichloroacetic acid soluble protein (TCA-SP), crude protein and ether extract contents of the FRSC were increased (P < 0.05) 103.71, 23.02 and 23.54%, respectively. As expected, the contents of NDF and phytic acid declined (P < 0.05) by 9.12 and 44.60%, respectively. Total amino acids (TAA) and essential amino acids (EAA) contents as well as AA in vitro digestibility of FRSC were improved significantly (P < 0.05). Moreover, the enzyme activity of endoglucanase, xylanase, acid protease and phytase were increased (P < 0.05) during SSF. Our results indicate that the solid state fermentation offers an effective approach to improving the quality of proteins sources such as rapeseed cake.

Direct fungal fermentation of lignocellulosic biomass into itaconic, fumaric, and malic acids: current and future prospects

Abstract: Various economic and environmental sustainability concerns as well as consumer preference for bio-based products from natural sources have paved the way for the development and expansion of biorefining technologies. These involve the conversion of renewable biomass feedstock to fuels and chemicals using biological systems as alternatives to petroleum-based products. Filamentous fungi possess an expansive portfolio of products including the multifunctional organic acids itaconic, fumaric, and malic acids that have wide-ranging current applications and potentially addressable markets as platform chemicals. However, current bioprocessing technologies for the production of these compounds are mostly based on submerged fermentation, which necessitates physicochemical pretreatment and hydrolysis of lignocellulose biomass to soluble fermentable sugars in liquid media. This review will focus on current research work on fungal production of itaconic, fumaric, and malic acids and perspectives on the potential application of solid-state fungal cultivation techniques for the consolidated hydrolysis and organic acid fermentation of lignocellulosic biomass.

Total phenolic contents, antioxidant activities, and lipid fractions from berry pomaces obtained by solid-state fermentation of two Sambucus species with Aspergillus niger.

Abstract: The aim of this study was to investigate the effect of solid-state fermentation (SSF) by Aspergillus niger on phenolic contents and antioxidant activity in Sambucus nigra L. and Sambucus ebulus L. berry pomaces. The effect of fermentation time on the total fats and major lipid classes (neutral and polar) was also investigated. During the SSF, the extractable phenolics increased with 18.82% for S. ebulus L. and 11.11% for S. nigra L. The levels of antioxidant activity of methanolic extracts were also significantly enhanced. The HPLC-MS analysis indicated that the cyanidin 3-sambubioside-5-glucoside is the major phenolic compound in both fermented Sambucus fruit residues. In the early stages of fungal growth, the extracted oils (with TAGs as major lipid fraction) increased with 12% for S. nigra L. and 10.50% for S. ebulus L. The GC-MS analysis showed that the SSF resulted in a slight increase of the linoleic and oleic acids level.

Efficient expression of nattokinase in Bacillus licheniformis: host strain construction and signal peptide optimization

Abstract: Nattokinase (NK) possesses the potential for prevention and treatment of thrombus-related diseases. In this study, high-level expression of nattokinase was achieved in Bacillus licheniformis WX-02 via host strain construction and signal peptides optimization. First, ten genes (mpr, vpr, aprX, epr, bpr, wprA, aprE, bprA, hag, amyl) encoding for eight extracellular proteases, a flagellin and an amylase were deleted to obtain B. licheniformis BL10, which showed no extracellular proteases activity in gelatin zymography. Second, the gene fragments of P43 promoter, Svpr, nattokinase and TamyL were combined into pHY300PLK to form the expression vector pP43SNT. In BL10 (pP43SNT), the fermentation activity and product activity per unit of biomass of nattokinase reached 14.33 FU/mL and 2,187.71 FU/g respectively, which increased by 39 and 156 % compared to WX-02 (pP43SNT). Last, Svpr was replaced with SsacC and SbprA, and the maximum fermentation activity (33.83 FU/mL) was achieved using SsacC, which was 229 % higher than that of WX-02 (pP43SNT). The maximum NK fermentation activity in this study reaches the commercial production level of solid state fermentation, and this study provides a promising engineered strain for industrial production of nattokinase, as well as a potential platform host for expression of other target proteins.

Solid state fermentation with lactic acid bacteria to improve the nutritional quality of lupin and soya bean.

Abstract: BACKGROUND The ability of bacteriocin-like inhibitory substance (BLIS)-producing lactic acid bacteria (LAB) to degrade biogenic amines as well as to produce l(+) and d(−)-lactic acid during solid state fermentation (SSF) of lupin and soya bean was investigated. In addition, the protein digestibility and formation of organic acids during SSF of legume were investigated. RESULTS Protein digestibility of fermented lupin and soya bean was found higher on average by 18.3% and 15.9%, respectively, compared to untreated samples. Tested LAB produced mainly l-lactic acid in soya bean and lupin (d/l ratio 0.38–0.42 and 0.35–0.54, respectively), while spontaneous fermentation gave almost equal amounts of both lactic acid isomers (d/l ratio 0.82–0.98 and 0.92, respectively). Tested LAB strains were able to degrade phenylethylamine, spermine and spermidine, whereas they were able to produce putrescine, histamine and tyramine. CONCLUSIONS SSF improved lupin and soya bean protein digestibility. BLIS-producing LAB in lupin and soya bean medium produced a mixture of d- and l-lactic acid with a major excess of the latter isomer. Most toxic histamine and tyramine in fermented lupin and soya bean were found at levels lower those causing adverse health effects. Selection of biogenic amines non-producing bacteria is essential in the food industry to avoid the risk of amine formation. © 2014 Society of Chemical Industry

Production and characterization of aroma compounds from apple pomace by solid-state fermentation with selected yeasts

Abstract: Volatile aroma profiles generated during apple pomace fermentation were characterized. The apple pomace was fermented with 4 yeast strains, using three strains of indigenous cider yeasts ( Saccharomyces cerevisiae , Hanseniaspora valbyensis and Hanseniaspora uvarum ) and a commercial S. cerevisiae combined with an enzymatic preparation as inocula. In all cases, the initial sugar content decreased until depletion within 21 days or less, yielding similar ethanol contents at the end of the alcoholic fermentation. Chromatographic analysis of the apple pomaces allowed the identification of 132 volatile compounds belonging to different chemical families. Quantitatively, the production of aromas was strongly strain-dependent. The apple pomaces inoculated with Saccharomyces strains accumulated higher levels of fatty acids and their corresponding ethyl esters, increasing throughout the period of study (28 days). On the other hand, the volatile profiles from experimental units fermented with Hanseniaspora genus yeasts were characterized by higher levels of acetic acid esters with a maximum at 7–14 days of fermentation. A significant decrease in the concentration of unsaturated carbonyls was also detected between 21 and 28 days in apple pomaces fermented with Hanseniaspora strains.

Fungal Lipase Production by Solid-State Fermentation

Abstract: Lipases are one of the most promising enzymes in the chemical and biopharmaceutical industries. Numerous applications have been reported including fine chemistry, detergents formulation and biodiesel synthesis. Lipases are commonly produced by a wide variety of yeasts and filamentous fungi in submerged fermentation or solid-state fermentation. Filamentous fungi and yeasts usually behave more efficiently in solid-state fermentation and show greater productivities when compared to submerged fermentation. Although filamentous fungi adequately growth in solid-state fermentation, there are some limitations for cultivating them by this process. Here, a review is made about lipase production in solid-state fermentation. This includes the analysis of solid-state fermentation as a promising technology, characterization of growth media and ambient factors such as moisture, pH and temperature.

Statistical Optimization of Laccase Production and Delignification of Sugarcane Bagasse by Pleurotus ostreatus in Solid-State Fermentation.

Abstract: Laccases are oxidative enzymes related to the degradation of phenolic compounds, including lignin units, with concomitant reduction of oxygen to water. Delignification is a necessary pretreatment step in the process of converting plant biomass into fermentable sugars. The objective of this work was to optimize the production of laccases and to evaluate the delignification of sugarcane bagasse by Pleurotus ostreatus in solid-state fermentation. Among eight variables (pH, water activity, temperature, and concentrations of CuSO4, (NH4)2SO4, KH2PO4, asparagine, and yeast extract), copper sulfate and ammonium sulfate concentrations were demonstrated to significantly influence laccase production. The replacement of ammonium sulfate by yeast extract and the addition of ferulic acid as inducer provided increases of 5.7- and 2.0-fold, respectively, in laccase activity. Optimization of laccase production as a function of yeast extract, copper sulfate, and ferulic acid concentrations was performed by response surface methodology and optimal concentrations were 6.4 g/L, 172.6 μM, and 1.86 mM, respectively. Experimentally, the maximum laccase activity of 151.6 U/g was produced at the 5th day of solid-state fermentation. Lignin content in sugarcane bagasse was reduced from 31.89% to 26.36% after 5 days and to 20.79% after 15 days by the biological treatment of solid-state fermentation.

Effect of solid-state fermentation with Cordyceps militaris SN-18 on physicochemical and functional properties of chickpea (Cicer arietinum L.) flour

Abstract: In the present study, Cordyceps militaris SN-18, a medicinal and edible mushroom generally recognized as safe (GRAS) filamentous fungus was used to ferment chickpeas by solid state fermentation (SSF). The main objective of this study was conducted to investigate the effects of SSF on protein composition of chickpea flour, as well as the subsequent effect on proximate composition, physicochemical and functional properties. Results showed that SSF increased the contents of the crude protein, true protein and essential amino acids, and SDS-PAGE demonstrated that proteins of fermented chickpeas were mainly composed of molecules of lower molecular mass compared to the non-fermented chickpeas. Fermented chickpea flours showed higher water absorption index, in vitro protein digestibility, and SSF improved water holding capacity, fat absorption capacity and emulsifying properties of chickpea flours. Additionally, fermented chickpea extracts demonstrated significant angiotensin I-converting enzyme (ACE) inhibitory activity. Thus, the study indicated that C. militaris fermentation improved the physicochemical and functional properties of chickpeas and it has great potential to design new nutritious food products and food formulations using C. militaris fermented chickpeas.