Fermented Wheat Bran Research Articles

Production of high-value bioproducts enriched with \u03b3-linolenic acid and \u03b2-carotene by filamentous fungi Umbelopsis isabellina using solid-state fermentations

Solid-state fermentation is a useful tool for utilizing different plant-based materials as cultivation substrates in order to produce potentially high-value fermented bioproducts. The aim of the present study was to successfully prepare various types of such bioproducts, using a zygomycetous strain Umbelopsis isabellina CCF2412. Various legume and cereal substrates were utilized effectively, while a few of them were obtained from agricultural waste, which is particularly advantageous from ecological and economic point of view. A common feature of the produced fermented materials was the increased content of different polyunsaturated fatty acids and carotenoid pigments in these bioproducts. Subsequent to the optimization of the solid-state fermentation process using cornmeal as the cultivation substrate, bioproducts enriched with γ-linolenic acid (11.45 mg γ-linolenic acid per gram of bioproduct), β-carotene (50.90 μg β-carotene per gram of bioproduct), and various microbial sterols were obtained. Appropriate n–6/n–3 acid ratio and enrichment of other microbial substances, such as the pigments and sterols mentioned above, in the fermented bioproducts widens the applicability of these bioproducts in different industries. The fermented cereal bioproducts produced in the present study from fermented wheat bran substrate were used for evaluating their application as feed for broiler chicken, and satisfactory results were obtained. Therefore, the present study creates novel opportunities for improving the quality of fermented bioproducts obtained during solid-state fermentation processes, especially for application in the feed industry.

Effect of Prebiotic Complex on Gut Microbiota and Endotoxemia in Female Rats with Modeled Heart Failure.

We studied the levels endotoxin and microbial markers in the blood of female rats with experimental heart failure and the effects of preliminary treatment with a prebiotic complex based on fermented wheat bran and inactivated Saccharomyces cerevisiae culture on these parameters. The concentrations of endotoxin, markers of lactobacilli, and opportunistic microorganisms were found to increase in rats with experimental heart failure and significantly decreased against the background of treatment with prebiotic complex. The dynamics of markers of bifidobacteria, eubacteria, and propionibacteria were reciprocal. The observed effect of the prebiotic complex effect on gut microbiota in rats with experimental heart failure suggests that this complex can be used for the correction of intestinal dysbiosis and endotoxemia in this clinical condition.

A diet containing native or fermented wheat bran does not interfere with natural microbiota of laying hens

Wheat bran (WB) is an important side product of the milling industry and can serve as dietary fiber compound for monogastric animals. The aim of this study was to evaluate the influence of native or fermented WB on the gut physiology and microbiology of laying hens. To accomplish this, 24 laying hens were fed the following diets: conventional diet without WB; 15% native WB in the diet; 15% WB fermented with Pleurotus eryngii; and 15% WB fermented with P. eryngii and a lactic acid bacterial culture. Immediately after slaughtering, digesta samples were taken from the jejunum, ileum and cecum, respectively. Total DNA was extracted and subsequently investigated with 16S DNA amplicon sequencing. Neither native nor fermented WB supplementations negatively affected the feed conversion ratio, laying performance or the relative abundances and alpha-diversity of microbiota in the intestine. Effects of WB-based diets on gut morphology were only recognized in the jejunum (reduced villum height and mucosa thickness). Likewise, WB supplementation decreased the digestibility of DM and starch. Based on these findings, it was demonstrated that different WB variants are applicable without exerting practically negative consequences on performance or on gut microbiota. Fermentation improved the digestibility/retention of dietary fat and phosphorus. However, no further beneficial effects were observed. This study also allowed a more in-depth view on the laying hens’ gut microbiome and its variation within the gut segments.

Fermented wheat bran by xylanase-producing Bacillus cereus boosts the intestinal microflora of broiler chickens

Wheat bran, while a nutritious and economic feed ingredient, contents high levels of non-starch polysaccharides which entraps nutrients and interferes digestion and absorption. To study the influence of fermented wheat bran by xylanase-producing Bacillus cereus on growth performance and intestinal microflora of broiler chickens, a total of 180 broilers (21-day-old, mixed of male and female) were randomly divided into 3 treatments, with 6 replicates in each treatment and 10 broilers in each replicate: 1) control check (CK), corn-soybean meal-based diet; 2) wheat bran group (WB), 5% of the corn were replaced with wheat bran; and 3) fermented wheat bran group (FWB), 5% of the corn were replaced with fermented wheat bran. Growth performance was determined in the period of 21- to 42-day-old. Intestinal digestive enzyme activities and microbiota diversity were analyzed on day 42. No differences were observed on growth performance among treatments (P > 0.05). The activity of amylase in the duodenum of FWB was 1.56 times higher than CK (P < 0.05). The Chao1 index of microbiota in cecum of FWB increased 24.26% compared with CK (P < 0.01). The amount of Bifidobacteriaceae in cecum of WB was 29.1 times and 15.8 times higher than CK and FWB (P < 0.05) respectively. Principal co-ordinates analysis in cecum revealed the dissimilarity microbiota among treatments. In summary, the use of fermented wheat bran to partially replace corn (5%) in diets had no adverse effect on growth performance and triggered beneficial effects such as increasing duodenal amylase activity and intestinal microflora abundance in broiler chickens. These observations support that solid-state fermentation by xylanase-producing Bacillus cereus is feasible approach to pre-treat wheat bran for feedstuff industry.

Microbial succession during wheat bran fermentation and colonisation by human faecal microbiota as a result of niche diversification

The human gut can be viewed as a flow-through system with a short residence time, a high turnover rate and a spatial gradient of physiological conditions. As a consequence, the gut microbiota is exposed to highly fluctuating environmental determinants presented by the host and diet. Here, we assessed the fermentation and colonisation of insoluble wheat bran by faecal microbiota of three individuals at an unprecedented sampling intensity. Time-resolved 16S rRNA gene amplicon sequencing, revealed a dynamic microbial community, characterised by abrupt shifts in composition, delimiting states with a more constant community, giving rise to a succession of bacterial taxa alternately dominating the community over a 72 h timespan. Early stages were dominated by Enterobacteriaceae and Fusobacterium species, growing on the carbohydrate-low, protein rich medium to which wheat bran was supplemented. The onset of wheat bran fermentation, marked by a spike in short chain fatty acid production with an increasing butyrate proportion and an increased endo-1,4-β-xylanase activity, corresponded to donor-dependent proportional increases of Bacteroides ovatus/stercoris, Prevotella copri and Firmicutes species, which were strongly enriched in the bran-attached community. Literature and database searches provided novel insights into the metabolic and growth characteristics underlying the observed succession and colonisation, illustrating the potency of a time-resolved analysis to increase our understanding of gut microbiota dynamics upon dietary modulations.

Solid state lactic acid fermentation: A strategy to improve wheat bran functionality

Wheat bran, a by-product produced in huge amount during cereal milling, is today largely unexploited because of its poor suitability as food ingredient. Solid-state fermentation (SSF) using a Lactobacillus rhamnosus strain was applied to wheat bran and its influence on bioactive compounds (free and bound phenolic acids) and antioxidant activity were evaluated. Moreover, the phytic acid (PAc) degradation and arabinoxylans (WEAX) solubilization properties were studied: the SSF treatment resulted in an almost 37% decrement and a three times increment of PAc and WEAX, respectively. Finally, in order to get the bigger picture, microbial metabolites and the volatile profile of fermented wheat bran were characterized, showing amino acids and lipids metabolites and a complex aroma profile. Overall, lactic acid fermentation can be considered a valuable pre-treatment for the valorisation of cereal by-products.

Astaxanthin biosynthesis: A two-step optimization approach and model construction with Response Surface Methodology and Artificial Neural Network

The first part of this research is investigating and comparing yield of a synthetic medium submerged three sugars (glucose, fructose and sucrose) at four different concentrations and solid fermentation systems with wheat bran and lentil waste for biosynthesis of astaxanthin (ASX) pigment by Xanthophyllomyces dendrorhous ATCC 24202 and Sporidiobolus salmonicolor ATCC 24259 microorganisms. The second part is modeling and optimizing the most efficient biosynthesis depending on waste, yeast and production variables consisted of moisture content, pH and temperature using a design matrix. The yields produced by X. dendrorhous were 51.88 µg of ASX/g glucose for the submerged medium with the least glucose, and 210.49 µg of ASX/g glucose for the wheat bran fermentation system. It was understood that the yield values of the submerged systems were lower and there was no requirement for the addition of any supplement to the waste systems. It was found that R2=0.9869 was the highest value with the maximum predicted ASX amount of 109.23 µg of ASX/g wheat bran with X. dendrorhous using Artificial Neural Network modeling and the moisture content was the most significant production parameter.

Solid-State Yeast Fermented Wheat and Oat Bran as A Route for Delivery of Antioxidants.

The purpose of our study was to evaluate the potential of solid-state yeast fermentation (SSYF) in improving the phenolic acid content and composition, and the antioxidant activity of commercial wheat bran (WB) and oat bran (OB). The ultrasound-assisted methanolic extracts were compared for their total phenolic content (TPC), phenolics composition, and in vitro antioxidant activity in order to study the effect of fermentation time on the chemical profile and activity of bioactive compounds. The comparative analysis revealed significant differences (p < 0.05) between days of fermentation (0 through 6). The highest TPCs were obtained on day 3 for WB (0.84 ± 0.05 mg of gallic acid equivalents [GAE]/g dry weight [DW]), and on day 4 for OB (0.45 ± 0.02 mg GAE/g DW). The highest relative percentage increase in the phenolics concentration of WB was also registered on day 3 (ferulic acid +56.6%, vanillic acid +259.3%, dihydroxybenzoic acids +161.2%, apigenin-glucoside +15.3%); for OB, this was observed on day 4 (avenanthramide 2f +48.5%, ferulic acid +21.2%). Enhanced antioxidant activities were significantly correlated with the highest TPCs. Our results suggest that SSYF may be a useful procedure for enrichment of antioxidants in cereal bran, considering the design of different functional foods and nutraceuticals.

English

Cellulases and xylanases are enzymes of industrial significance, particularly in the pulp, paper, textile, and animal feed industries. Moreover, their utilization in the food industry, among them, bakery, brewery, winery and fruit and vegetable juice production, cannot be underestimated. One of the potential sources of enzymes is the filamentous fungi, and hence bio-prospecting of this specific group of microorganisms with the highest levels of cellulase and xylanase secretions is being continuously undertaken. The specific aim of this study was to isolate and characterize cellulase- and xylanase-producing filamentous fungi from termite mounds. Termite mounds have long been established as very good sources of filamentous fungi with the ability to secrete high levels of lignocellulolytic enzymes, and hence an ideal target for the bio-prospecting of cellulases and xylanases. In this study, various groups of filamentous fungi were isolated through enrichment and repeated sub-culturing. This was followed by screening using the Congo red plate-based assay. Cellulase and xylanase activities during the solid-state fermentation of wheat bran were detected and analyzed through spectrophotometry via the 3,5-dinitrosalicylic acid detection system for reducing sugars. The obtained fungal isolates were then finally characterized through zymography, reaction kinetics and morphological studies. Overall, a total of eight different groups of fungi, capable of decomposing cellulose and hemicellulose, were isolated, and their tentative identities established as Fusarium, Didymostible, Penicillium, Phytophthora, Oedocephalum, Aspergillus, Monosporascus and Acremonium. Taken together, findings of this study conceivably showed that termite mounds are a good source of filamentous fungi that in turn are also a good source of cellulases and xylanases that arguably, can be recommended for use in industrial and commercial settings. Key words: Filamentous fungi, lignocellulosic substrates, lignocellulolytic enzymes, cellulases, xylanases, termite mounds, termite nests, fungal combs.

Production of cellulases by Thermomucor indicae-seudaticae: characterization of a thermophilic β-glucosidase

The current study evaluated the production and characterization of β-glucosidase by the thermophilic fungus Thermomucor indicae-seudaticae in solid-state fermentation of wheat bran. Isolated fungi have significant amounts of β-glucosidase, an enzyme that may be applied to different industrial processes, such as the production of fuels, food, and other chemical compounds. Maximal enzyme activity occurred in pH 3.5–4.5 and at 70 °C. The enzyme exhibited high thermostability, for 1 h, up to 60 °C, and good tolerance to glucose (10 mM) and ethanol (10%). The optimization of fermentative parameters on the production of β-glucosidase was carried out by evaluating the best supplementary nutrient source, pH of nutrient solution, initial substrate moisture and fermentation temperature. The optimization of the above fermentation parameters increased enzyme activity by 120.0%. The highest enzymatic activity (164.0 U/g) occurred with wheat bran containing 70% initial moisture, supplemented with 1.0% (NH4)2SO4 solution at pH 5.5–6.0 and fungus incubated at 40 °C. A more detailed study of β-glucosidase suggested that Sulfur is an important component of the main amino acid present in this enzyme. The enhancer of the enzyme activity occurred when the fungus was grown on wheat bran supplemented with a sulfur-containing solution. In fact, increasing the concentration of sulfur in the solution increased its activity.

Microbial and nutritional characteristics of fermented wheat bran in traditional Romanian borş production

Microbial and nutritional characteristics of fermented wheat bran in traditional Romanian borş production

Isolation of wheat bran-colonizing and metabolizing species from the human fecal microbiota.

Undigestible, insoluble food particles, such as wheat bran, are important dietary constituents that serve as a fermentation substrate for the human gut microbiota. The first step in wheat bran fermentation involves the poorly studied solubilization of fibers from the complex insoluble wheat bran structure. Attachment of bacteria has been suggested to promote the efficient hydrolysis of insoluble substrates, but the mechanisms and drivers of this microbial attachment and colonization, as well as subsequent fermentation remain to be elucidated. We have previously shown that an individually dependent subset of gut bacteria is able to colonize the wheat bran residue. Here, we isolated these bran-attached microorganisms, which can then be used to gain mechanistic insights in future pure culture experiments. Four healthy fecal donors were screened to account for inter-individual differences in gut microbiota composition. A combination of a direct plating and enrichment method resulted in the isolation of a phylogenetically diverse set of species, belonging to the Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria phyla. A comparison with 16S rRNA gene sequences that were found enriched on wheat bran particles in previous studies, however, showed that the isolates do not yet cover the entire diversity of wheat-bran colonizing species, comprising among others a broad range of Prevotella, Bacteroides and Clostridium cluster XIVa species. We, therefore, suggest several modifications to the experiment set-up to further expand the array of isolated species.

Effect of adding formaldehyde treated protein alone and with Saccharomyces cerevisiae in diet on plane of nutrition, growth performance, rumen fermentation and microbial protein synthesis of finisher lambs

Thirty nine (three months old) lambs were randomly divided into three treatment groups, each having thirteen lambs who were reared up to six months of age on ad libitum finisher ration (concentrates and cowpea hay). The three treatments were control (T1) that offered finisher ration consisting of untreated protein concentrates and the other two test groups T2 and T3 were offered finisher ration with formaldehyde treated (12 g formaldehyde/Kg CP) soy flakes (7%) and groundnut cake (5%). Additionally, T3 was supplemented with probiotics (Saccharomyces cerevisiae) in the form of fermented wheat bran. Plane of nutrition revealed higher (P < 0.05) intake of concentrate, dry matter (DM), metabolizable energy (ME) and digestible crude protein (CP) in T2 and T3 as compared to T1. This supported higher body weight gain and average daily gain with improved feed conversion ratio in T2 and T3 while the effect of probiotic supplementation was not significant (P > 0.05). There was also improvement in digestibility of CP and N retained in body in T2 and T3 as compared to T1. A decreased rumen ammonia with increased excretion of purine derivatives and microbial protein synthesis was observed in T2 and T3 compared to T1. The T2 and T3 groups recorded lower serum cholesterol compared to T1. It may thus be concluded that supplementation of formaldehyde treated protein concentrate in the ration of lambs during post-weaning period could support higher plane of nutrition with improved protein digestibility, N retained and utilization leading to increased live weight gain with a better feed conversion efficiency. Although, additional benefit of feeding probiotic to lambs on a high concentrate diet was not evident, fermented wheat bran with S. cerevisae could be a practical way of feeding probiotics to ruminants.

Anticoagulant activity of partially purified chitinase produced by Citrobacter freundii str. nov. haritD11 by fermentation of wheat bran coupled with fish scales

Solid phase fermentation of wheat bran coupled with powdered fish scales could yield chitinase using a novel Citrobacter strain. The fermentation conditions are optimized conventionally (84.14 U/gds) and statistically (94.3 U/gds). The partially purified chitinase had a specific activity of 53.41 U/mg with optimal activity at pH 8.5 and 50 °C, it was stable at 7.5–10 pH range for 24 h with more than 80% stability at 45–60 °C, and the Km value of chitinase with swollen chitin (substrate) is 8.11 mg/ml with a Vmax of 2.43 mmol h−1 ml−1. The partially purified enzyme was halotolerant showing maximum activity and stability up to 10% of Nacl, also possessing potential anticoagulant activity. This is the first report to date elucidating the production of halotolerant chitinase from wheat bran supplemented with fish scales using Citrobacter freundii haritD11 and its application as an anticoagulant agent and notable tolerance to heavy metal ions.

Potential of in situ SSF laccase produced from Ganoderma lucidum RCK 2011 in biobleaching of paper pulp.

Production of laccase from Ganoderma lucidum RCK 2011 under solid-state fermentation (SSF) conditions was optimized using response surface methodology, resulting in an approximate eightfold increase compared to that in the unoptimized media. Further, the enzyme produced under SSF as whole fermented substrate (in situ SSF laccase) was found to be more stable than the in vitro enzyme (harvested by downstreaming processing of fermented wheat bran). Interestingly, the biobleaching potentials of both in situ and in vitro SSF laccases were comparable, saving 25% chlorine dioxide for achieving similar pulp brightness as obtained in the pulp treated chemically. The reduction in the demand of chlorine dioxide in the pulp bleaching sequence subsequently decreased the levels of adsorbable organic halogen (AOX) in the resulting effluents of the process by 20% compared to the effluents obtained from chemical bleaching sequence. Therefore, direct application of in situ SSF laccase in pulp biobleaching will be environmentally friendly as well as economical and viable for implementation in paper mills.

Effects of Fermented Wheat Bran on Flour, Dough, and Steamed Bread Characteristics

Wheat bran is rich in dietary fiber, which improves the flour nutritional content and also endows the flour with a richer flavor. However, a high content of insoluble dietary bran fiber can easily and significantly reduce the processing and edible quality of flour products. This study was conducted to explore ways to decrease the negative effects of adding bran to dough. Basidiomycete strain BS-01 was used to ferment the wheat bran. The surface structure of the bran was examined by scanning electron microscopy, and the fermented bran was incorporated into the wheat flour at various concentrations. The mixed flour farinographic and extensographic characteristics, dough rheological properties, and the specific volume, color, and textural properties of the steamed bread were determined and analyzed. The results suggested that adding an appropriate quantity of fermented bran improves the characteristics of the dough and the quality of the steamed bread compared to those with unfermented bran. The fermented bran effectively decreased the negative impacts exerted on the farinographic and extensographic characteristics of the mixed flour and exerted a positive influence on the dough viscoelasticity and bread specific volume.

Investigation on “spontaneous fermentation” and the productivity of microbial exopolysaccharides by Lactobacillus plantarum and Pediococcus pentosaceus isolated from wheat bran sourdough

Spontaneously fermented wheat bran sourdough (WBS) is a source of lactic acid bacteria (LAB) and metabolites with potential applications as functional ingredients. In this study, dominant LAB isolated from the spontaneous fermentation of WBS were analyzed for their exopolysaccharide (EPS) production capacities. Biochemical and molecular tests led to the identification of Lactobacillus plantarum and Pediococcus pentosaceus as the dominant isolates. Compositional analysis of microbial EPSs revealed the presence of 71.44 and 94.64% total carbohydrate content, 1.56 and 3.48% total protein content, and 0.23 and 0.49% w/w of phosphorus content for L. plantarum and P. pentosaceus, respectively. The molecular weight of EPS isolated from L. plantarum (5.36 × 105 Da) was greater than that of P. pentosaceus (4.65 × 105 Da). DPPH radical scavenging capacity, ABTS, and reducing power (FRAP) of the EPSs were significantly different (P < 0.05). FT-IR spectroscopy analysis demonstrated that the EPSs were complex polysaccharides containing different functional groups represented by stretching vibrations related to alcoholic, carboxylic acid and aromatic groups. In the context of their importance in sourdough fermentation, the EPSs demonstrated potential antioxidant properties.

Soluble Dietary Fiber Reduces Trimethylamine Metabolism via Gut Microbiota and Co-Regulates Host AMPK Pathways.

Evidence from animal experiments and clinical medicine suggests that high dietary fiber intake, followed by gut microbiota-mediated fermentation, decreases trimethylamine (TMA) metabolism, the mechanism of which, however, remains unclear. The objective of this analysis was to evaluate, using mice fed with red meat, the effects of soluble dietary fiber (SDF) intervention on TMA metabolism. Low- or high-dose soluble dietary fiber (SDF) from natural wheat bran (LN and HN, low- and high-dose natural SDF), fermented wheat bran (LF and HF, low- and high-dose fermented SDF), and steam-exploded wheat bran (LE and HE, low- and high-dose exploded SDF groups) were used to examine whether SDF interventions in mice fed with red meat can alter TMA and trimethylamine N-oxide (TMAO) metabolism by gut microbial communities in a diet-specific manner. Results demonstrated that SDF-diets could reduce TMA and trimethylamine N-oxide (TMAO) metabolism by 40.6 and 62.6%, respectively. DF feeding, particularly fermented SDF, reshaped gut microbial ecology and promoted the growth of certain beneficial microflora species. SDF-diet decreased energy intake, weight gain, intestinal pH values, and serum lipid and cholesterol levels. SDF-diet also enhanced the production of short chain fatty acids with activation of the intestinal epithelial adenosine monophosphate-activated protein kinase (AMPK). These findings suggest a central mechanism via which SDF-diet may control TMA metabolism by gut microflora and co-regulate the AMPK pathways of the host.

Comparison of releasing bound phenolic acids from wheat bran by fermentation of three Aspergillus species

SummaryWheat bran was fermented at 28 °C for 7 days under 70% humidity by Aspergillus niger, Aspergillus oryzae and Aspergillus awamori. Total phenolic content (TPC) of the unfermented sample was 1531.5 μg g−1 wheat bran. After the fermentation of Aspergillus awamori, Aspergillus oryzae and Aspergillus niger, TPC reached 5362.1, 7462.6 and 10 707.5 μg g−1, respectively. The antioxidant activity in the extractions of fermented wheat bran also increased significantly compared with the unfermented sample (P &lt; 0.05). Aspergillus niger showed the greatest capacity to release bound ferulic acid (416.6 μg g−1). Aspergillus oryzae and Aspergillus awamori had the advantages of releasing more chlorogenic acid (84.0 μg g−1) and syringic acid (142.3 μg g−1), respectively. The destructive effect of Aspergillus niger on wheat bran structure was the strongest, followed by that of Aspergillus oryzae. This effect of Aspergillus niger may be due to its higher cellulase, xylanase, arabinofuranosidase and β‐xylosidase activities. Besides, Aspergillus oryzae possessed higher β‐glucosidase activity, and Aspergillus awamori had higher α‐amylase and feruloyl esterase activities. Aspergillus niger may be the best to release bound phenolic acids in the three Aspergillus species. These will provide the helpful information for understanding mechanism of the fermentation by Aspergillus species releasing bound phenolic in wheat bran.

Enzymatic saccharification of seaweeds into fermentable sugars by xylanase from marine Bacillus sp. strain BT21.

Enzymatic hydrolysis of seaweed biomass was studied using xylanase produced from marine bacteria Bacillus sp. strain BT21 through solid-state fermentation of wheat bran. Three types of seaweeds, Ahnfeltia plicata, Padina tetrastromatica and Ulva lactuca, were selected as representatives of red, brown, and green seaweeds, respectively. Seaweed biomass was pretreated with hot water. The efficiency of pretreated biomass to release reducing sugar by the action of xylanase as well as the type of monosaccharide released during enzyme saccharification of seaweed biomass was studied. It was seen that pretreated biomass of seaweed A. plicata, U. lactuca, and P. tetrastroma, at 121°C for 45min, followed by incubation with 50IU xylanase released reducing sugars of 233±5.3, 100±6.1 and 73.3±4.1µg/mg of seaweed biomass, respectively. Gas chromatography analysis illustrated the release of xylose, glucose, and mannose during the treatment process. Hot water pre-treatment process enhanced enzymatic conversion of biomass into sugars. This study revealed the important role of xylanase in saccharification of seaweed, a promising feedstock for third-generation bioethanol production.