Search Results (18)

Sourdough fermentation has emerged as a promising biotechnological approach to reducing gluten content and modifying gluten proteins in wheat-based products. This review assesses the current scientific literature on the enzymatic degradation and hydrolysis of gluten during lactic acid bacteria (LAB) sourdough fermentation. It explores implications for individuals with gluten-related disorders, including celiac disease, non-celiac gluten sensitivity and intolerance, as well as irritable bowel syndrome (IBS). In addition, LAB sourdough effect on fermentable oligo-, di-, monosaccharides and polyols (FODMAPs), amylase-trypsin inhibitors (ATIs), and phytate are revised. Selected homo- and heterofermentative LAB are capable of degrading gluten proteins, especially the polypeptides derived from the action of native cereal proteases. Mixed cultures of LAB degrade gluten peptides more effectively than monocultures. However, LAB sourdough is not sufficient to remove the toxic peptides to the minimal level (<20 ppm). This goal is achieved only if sourdough is combined with fungal proteases during sourdough fermentation. LAB sourdough directly contributes to lower FODMAPs but not ATIs and phytate. Phytate is reduced by the endogenous cereal phytases activated at acidic pHs (pH < 5.0), conditions generated during sourdough fermentation. ATIs are also lowered by endogenous cereal proteases instead of LAB proteases/peptidases. Despite LAB sourdough not fully degrading the gluten or directly reducing the ATIs and phytate, it participates through peptidases activity and acidic pH that trigger the action of endogenous cereal proteases and phytases. Full article

In order to meet the ever-growing needs of society, modern agriculture must develop sustainable farming and livestock production. Crops need phosphorus, a macronutrient found in soils, but they are only able to utilize small quantities of it. Chemical phosphate fertilizers are ineffective and environmentally harmful. The use of microorganisms (bacteria, yeast, filamentous fungi, and microalgae) that synthesize phytases is a promising and environmentally friendly alternative to chemical fertilizers. Phytases are also needed as feed additives in animal husbandry to overcome phosphorus deficiency for animal growth and development. Phytases are phosphatases that catalyze the release of phosphorus from phytate by stepwise hydrolysis. The broad substrate specificity, optimal pH range, higher thermal stability, and specific efficiency of fungal phytases make them interesting enzymes for agricultural applications. They improve and stimulate the growth and development of plants and animals by releasing inorganic phosphorus and producing siderophores, organic acids, hydrogen cyanide, ammonia, and phytohormones. Phytases are crucial for enhancing phosphorus use in farming and decreasing phosphorus waste’s environmental effects. This paper addresses key challenges in modern farming, such as the inefficient utilization of phosphorus from soil and the environmental harm caused by chemical fertilizers, and provides a comprehensive overview of recent advances in the research of fungal phytases. Available scientific data have been synthesized to highlight the potential of phytase use in agriculture. This review outlines key areas for future research, including the development of phytase variants with improved functionality. The potential integration of fungal phytases into sustainable agricultural practices is underlined, in contrast to previously published work focused primarily on their biochemical properties. The review offers new insight into the possible applications of micromycete phytases as a critical factor for sustainable agriculture in the future. Full article

The co-product canola meal contains little fat and has been used in swine production as a protein source for several decades. More recently, locally produced canola cake has also become available that contains important quantities of residual oil. Both canola co-products contain a considerable quantity of phosphorus (P) with low availability. Phytase supplementation can increase P digestibility in canola meal but its efficacy remains unclear for canola cake containing high residual oil. To explore whether phytase supplementation can increase digestibility of P and other nutrients in canola cake, four diets containing 500 g of locally produced cold-pressed canola cake or canola meal, with or without supplemental phytase (Ronozyme HiPhos; Aspergillus oryzae origin)/kg, were fed to seven pigs (initial body weight; 55.9 ± 3.8 kg) in four 9-day periods following a 4 × 4 Latin square plus a 4 × 3 Youden square. Phytase supplementation increased phytase activity from below the detection limit to reach a minimum of 1000 phytase units/kg in the canola meal and cake diets; respectively. Phytase supplementation increased (p < 0.05) coefficients of ileal and total tract digestibility of P by 60% and 46% for canola meal and 76% and 57% for canola cake, respectively, but did not affect the digestibility of crude protein or gross energy. Ileal or total tract digestibility of P did not differ between the canola cake and canola meal diets in growing-finishing pigs. In conclusion, fungal phytase is effective in increasing the P digestibility of canola cake similar to in canola meal fed to growing-finishing pigs. The similar ileal or total tract digestibility of P in canola meal and cake diets either with or without phytase supplementation indicated that the residual oil in canola cake did not affect P digestion and did not affect the efficacy of phytase in increasing P digestibility. Full article

A ten-week trial was conducted to evaluate the enhancement of production performance and nutrient utilization of laying hens through augmenting energy, phosphorous, and calcium deficient diets with fungal phytase (Trichoderma reesei) supplementation. 720 Hy-line Brown hens aged 28 weeks were randomly divided into 5 groups; each group had 8 replicates of 18 hens. Five experimental diets were prepared and fed to corresponding groups. A positive control (PC) diet contained 3.50% of calcium (Ca), 0.32% of non-phytate phosphorus (NPP), and apparent metabolic energy (AME) of 11.29MJ/kg, while a negative control (NC) diet contained 3.30% of Ca, 0.12% of NPP, and lower AME of 300 kJ/kg. The other three diets were supplemented with 250 FTU/kg phytase (PHY-250), 1000 FTU/kg phytase (PHY-1000), and 2000 FTU/kg phytase (PHY-2000) in addition to a regular NC diet. Results indicated that the positive control (PC) diet group had higher body weight gain, egg weight, and average daily feed intake. However, laying rate, egg mass, and FCR were most improved in the PHY-2000 group, followed by the PHY-1000 and PHY-250 groups (p < 0.05). Improved yolk color was most notable in laying hens fed the diet with PHY-1000 as opposed to the PC and NC groups (p < 0.05), but no overall difference was found among all of the phytase treated groups. The apparent availability of dry matter, energy, phosphorus, and phytate P was significantly higher in the PHY-2000 group than in the PC and NC groups (p < 0.05). Compared to the PC group, nitrogen retention was significantly higher in the PHY-1000 group, while calcium availability was higher in the PHY-250 group. The results suggested that the addition of phytase to diets with low P, Ca, and AME improved laying performance and apparent availability of dietary nutrients. Thus, it was concluded that the laying hen diet could be supplemented with 1000–2000 FTU/kg phytase for improving laying production and nutrient availability and mitigating the negative impact of reduced nutrient density in laying hen diets. Full article

Oidiodendron maius G.L. Barron is a recognized fungal species capable of forming ericoid mycorrhiza with various positive effects on host plants; therefore, newly found and previously uncharacterized O. maius strains may be valuable for heather plants’ controlled mycorrhization. Characteristics of the O. maius F3860 strain were studied, i.e., mycelium growth on various nutrient media and the ability to secrete auxins and enzymes. O. maius F3860 grew rapidly on malt extract agar and potato dextrose agar. It was also able to grow on nutrient media suitable for heather plant cultivation. The presence of the flavonoids rutin and quercetin increased the mycelium growth rate compared to the control, starting from the 8th to the 13th days of cultivation. The ability to secrete auxins was confirmed with bioassay and thin-layer chromatography, and their content, as well as phytase activity, was estimated spectrophotometrically. Both in nutrient media with tryptophan and without it, O. maius F3860 secreted about 6 μg IAA/mL growth medium. O. maius F3860 possessed extracellular phytase, protease, and phenol oxidase activities. The investigation indicates O. maius F3860’s promise for heather seedling inoculation as an approach to increase their fitness. Full article

Cucumber is one of the most commonly produced vegetable crops. The greatest economic losses in the yields of these crops have resulted from fungal infections—powdery mildew and downy mildew. The action of fungicides not only affects the fungi, but can also lead to metabolic disorders in plants. However, some fungicides have been reported to have positive physiological effects. Our research focused on the action of two commercially available fungicides, Scorpion 325 SC and Magnicur Finito 687,5 SC, on plant metabolism. Two approaches were used to check the effect of the fungicides at the early stage of plant development when metabolic changes occur most dynamically: spraying on the leaves of cucumber seedlings and presowing seed treatment. The application of the fungicide formulation as a presowing seed treatment caused perturbations in the phytase activity, leading to disorders in the energetic status of the germinating seeds. In addition, the tested preparations changed the morphology of the germinating seeds, limiting the growth of the stem. Furthermore, the application of the tested fungicides on seedlings also showed a disruption in the energetic status and in the antioxidative system. Therefore, the use of pesticides as agents causes a “green effect” and requires a much deeper understanding of plant metabolism. Full article

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been responsible for approximately 6.8 million deaths worldwide, threatening more than 753 million individuals. People with severe coronavirus disease-2019 (COVID-19) infection often exhibit an immunosuppression condition, resulting in greater chances of developing co-infections with bacteria and fungi, including opportunistic yeasts belonging to the Saccharomyces and Candida genera. In the present work, we have reported the case of a 75-year-old woman admitted at a Brazilian university hospital with an arterial ulcer in the left foot, which was being prepared for surgical amputation. The patient presented other underlying diseases and presented positive tests for COVID-19 prior to hospitalization. She received antimicrobial treatment, but her general condition worsened quickly, leading to death by septic shock after 4 days of hospitalization. Blood samples collected on the day she died were positive for yeast-like organisms, which were later identified as Saccharomyces cerevisiae by both biochemical and molecular methods. The fungal strain exhibited low minimal inhibitory concentration values for the antifungal agents tested (amphotericin B, 5-flucytosine, caspofungin, fluconazole and voriconazole), and it was able to produce important virulence factors, such as extracellular bioactive molecules (e.g., aspartic peptidase, phospholipase, esterase, phytase, catalase, hemolysin and siderophore) and biofilm. Despite the activity against planktonic cells, the antifungals were not able to impact the mature biofilm parameters (biomass and viability). Additionally, the S. cerevisiae strain caused the death of Tenebrio molitor larvae, depending on the fungal inoculum, and larvae immunosuppression with corticosteroids increased the larvae mortality rate. In conclusion, the present study highlighted the emergence of S. cerevisiae as an opportunistic fungal pathogen in immunosuppressed patients presenting several severe comorbidities, including COVID-19 infection. Full article

Plants’ mineral nutrition in acidic soils can be facilitated by phosphate solubilizing fungi inhabiting the root systems of these plants. We attempt to find dark septate endophyte (DSE) isolates in the roots of wild-heather plants, which are capable of improving plants’ phosphorus nutrition levels. Bright-field and confocal laser scanning microscopy were used for the visualization of endophytes. A model system of co-cultivation with Vaccinium macrocarpon Ait. was used to study a fungal isolate’s ability to supply plants with phosphorus. Fungal phytase activity and phosphorus content in plants were estimated spectrophotometrically. In V. vitis-idaea L. roots, we obtained a Phialocephala fortinii Wang, Wilcox DSE2 isolate with acid phytase activity (maximum 6.91 ± 0.17 U on 21st day of cultivation on potato-dextrose broth medium) and the ability to accumulate polyphosphates in hyphae cells. The ability of the isolate to increase both phosphorus accumulation and biomass in V. macrocarpon is also shown. The data obtained for the same isolate, as puzzle pieces put together, indicate the possible mediation of P. fortinii DSE2 isolate in the process of phosphorus intake from inorganic soil reserves to plants. Full article

Phytic acid is an organic phosphorus source naturally produced by plants as phosphorus stock and can be an alternative to rock phosphate, which is a dwindling resource globally. However, phytic acid is insoluble, owing to its binding to divalent metals and is, thus, not readily bioavailable for plants and monogastric livestock. Therefore, the enzyme phytase is indispensable for hydrolyzing phytic acid to liberate free phosphates for nutritional availability, making the screening of novel phytase-producing microbes an attractive research focus to agriculture and animal feed industries. In the present study, a soil-extract-based culture medium was supplemented with phytic acid as the sole phosphorus source and oligotrophic phytase-producing strains, which had not been previously studied, were isolated. Four fungal strains with phytic acid, assimilation activities were isolated. They were found to produce phytase in the culture supernatants and phylogenetic analysis identified three strains as basidiomycetous yeasts (Saitozyma, Leucosporidium, and Malassezia) and one strain as an ascomycetous fungus (Chaetocapnodium). The optimal pH for phytase activity of the strains was 6.0–7.0, suggesting that they are suitable for industrial applications as feed supplements or fertilizer additives for farmland. Full article

Biological-based conversion of agricultural residues into bioactive compounds may be considered to be the basis for various vital industries. However, finding a suitable microorganism is a challenge in the bioconversion process. Therefore, this study was conducted to find local fungal isolates able to convert a combination of plant biomass residues into organic acids (OAs). Based on their cellulase and phytase activities and rock phosphate (RP) solubilization potential, an efficient 15 fungal isolates (named F1 to F15) were selected and identified by both morphological and molecular methods using the 18S rRNA sequencing technique. The best fungal isolate (F15) was identified as Aspergillus japonicus. After 4 weeks of incubation below solid-state fermentation (SSF) with a mix of sugarcane bagasse and faba bean straw (3:7), with 7.5% (v/w) fungal inoculum to the growth medium, the biodegradation process by the fungus reached its peak, i.e., maximum cellulolytic activity and RP solubilization ability. Under such fermentation conditions, seven organic acids were detected using HPLC, in the following order: ascorbic acid > oxalic acid > formic acid > malic acid > succinic acid > lactic acid > citric acid. Based on the results, Aspergillus japonicus (F15) could produce OAs and cellulose enzymes, and could be considered a new single-step bio-converter of sugarcane bagasse and faba bean straw residues into OAs. Furthermore, this fungus could be a new source of fungal cellulose, and could present a practical approach to reducing environmental contamination. Additional work is encouraged for more optimization of fermentation conditions. Full article

Although considered rare, the emergent Candida haemulonii species complex, formed by C. haemulonii sensu stricto (Ch), C. duobushaemulonii (Cd) and C. haemulonii var. vulnera (Chv), is highlighted due to its profile of increased resistance to the available antifungal drugs. In the present work, 25 clinical isolates, recovered from human infections during 2011–2020 and biochemically identified by automated system as C. haemulonii, were initially assessed by molecular methods (amplification and sequencing of ITS1-5.8S-ITS2 gene) for precise species identification. Subsequently, the antifungal susceptibility of planktonic cells, biofilm formation and susceptibility of biofilms to antifungal drugs and the secretion of key molecules, such as hydrolytic enzymes, hemolysins and siderophores, were evaluated by classical methodologies. Our results revealed that 7 (28%) isolates were molecularly identified as Ch, 7 (28%) as Chv and 11 (44%) as Cd. Sixteen (64%) fungal isolates were recovered from blood. Regarding the antifungal susceptibility test, the planktonic cells were resistant to (i) fluconazole (100% of Ch and Chv, and 72.7% of Cd isolates), itraconazole and voriconazole (85.7% of Ch and Chv, and 72.7% of Cd isolates); (ii) no breakpoints were defined for posaconazole, but high MICs were observed for 85.7% of Ch and Chv, and 72.7% of Cd isolates; (iii) all isolates were resistant to amphotericin B; and (iv) all isolates were susceptible to echinocandins (except for one isolate of Cd) and to flucytosine (except for two isolates of Cd). Biofilm is a well-known virulence and resistant structure in Candida species, including the C. haemulonii complex. Herein, we showed that all isolates were able to form viable biofilms over a polystyrene surface. Moreover, the mature biofilms formed by the C. haemulonii species complex presented a higher antifungal-resistant profile than their planktonic counterparts. Secreted molecules associated with virulence were also detected in our fungal collection: 100% of the isolates yielded aspartic proteases, hemolysins and siderophores as well as phospholipase (92%), esterase (80%), phytase (80%), and caseinase (76%) activities. Our results reinforce the multidrug resistance profile of the C. haemulonii species complex, including Brazilian clinical isolates, as well as their ability to produce important virulence attributes such as biofilms and different classes of hydrolytic enzymes, hemolysins and siderophores, which typically present a strain-dependent profile. Full article

Indigenous fungi present in agricultural soils could have synchronized their inherent potentials to the local climatic conditions. Therefore, the fungi resident in the untreated wastewater irrigated agricultural field might develop their potential for producing various enzymes to handle the induced full organic load from domestic wastewater and toxic chemicals from the textile industry. Around 53 various fungal isolates were grown and separated from the soil samples from these sites through soil dilution, soil-culture plate, and soil-culture plate methods. All the purified fungi were subjected to a phosphatase production test, and only 13 fungal strains were selected as phosphatase producers. Among them, only five fungi identified as Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium purourogenum, and Mucor rouxii based on morphological similarities, showing higher phosphate solubilizing indices, were utilized for eco-cultural fine-tuning to harness their full production potential under shake flask (SF) method. Among various media, orchestral tuning, 200 µM sodium phytate as substrate with 1.5 mL of inoculum size of the fungi, pH 7, temperature 30 °C, glucose, and ammonium nitrate as carbon and nitrogen additive with seven days of incubation were found to be the most appropriate cultural conditions to harness the phytase production potential of the selected fungi. Aspergillus niger and Aspergillus flavus showed initial phytase activity (5.2 Units/mL, 4.8 Units/mL) and phytase specific activity (2.85, 2.65 Units/mL per mg protein) during screening to be enhanced up to 17 ± 0.033 (Units/mL), 16 ± 0.033 (Units/mL) and (13 ± 0.012), 10 ± 0.066 (Units/mL per mg protein), respectively, with the above-mentioned conditions. The phytase enzyme produced from these fungi were found to be almost stable for a wide range of pH (4–8); temperature (20–60 °C); insensitive to Ca²⁺ and Mg²⁺ ions, and EDTA, Ni²⁺, and Ba²⁺ inhibitors but highly sensitive to Mn²⁺, Cu²⁺, and Zn²⁺ ions, and Co²⁺, Cr³⁺, Al³⁺, Fe²⁺ and Ag¹⁺ inhibitors. It was suggested that both phytase-producing strains of A. niger and A. flavus or their crude phytase enzymes might be good candidates for application in soils to release phosphates from phytate and a possible valuable substitute of phosphate fertilizers. Full article

Phytate represents an organic pool of phosphorus in soil that requires hydrolysis by phytase enzymes produced by microorganisms prior to its bioavailability by plants. We tested the ability of a microbial suspension made from an old growth maple forest’s undisturbed soil to mineralize phytate in a greenhouse trial on soybean plants inoculated or non-inoculated with the suspension. MiSeq Amplicon sequencing targeting bacterial 16S rRNA gene and fungal ITS was performed to assess microbial community changes following treatments. Our results showed that soybean nodulation and shoot dry weight biomass increased when phytate was applied to the nutrient-poor substrate mixture. Bacterial and fungal diversities of the root and rhizosphere biotopes were relatively resilient following inoculation by microbial suspension; however, bacterial community structure was significantly influenced. Interestingly, four arbuscular mycorrhizal fungi (AMF) were identified as indicator species, including Glomus sp., Claroideoglomus etunicatum, Funneliformis mosseae and an unidentified AMF taxon. We also observed that an ericoid mycorrhizal taxon Sebacina sp. and three Trichoderma spp. were among indicator species. Non-pathogenic Planctobacteria members highly dominated the bacterial community as core and hub taxa for over 80% of all bacterial datasets in root and rhizosphere biotopes. Overall, our study documented that inoculation with a microbial suspension and phytate amendment improved soybean plant growth. Full article

To evaluate in possible use of phytases for improving the utilization of low protein and energy diets, 420, one-day-old chicks were distributed among 7 groups (5 replicates of 12 chicks/group). During the starter (1–35 day), grower (37–56 day), and finisher (57–64 day) periods, the control group fed diets containing 21.2% crude protein (CP)-2947 Kcal/kg metabolizable energy (ME), 19.6 CP-3023 ME and 18.0 CP-3100 ME, respectively. The three low-CP groups received diets isocaloric but with −1% CP than the control, while the three low-CPME groups fed diets with −1% CP and −100 Kcal than the control. In addition, the low-CP and low-CPME groups were supplemented with 0 (low-CP_uns and low-CPME_uns), 500 U/kg of an Aspergillus niger (low-CP_AP and low-CPME_AP) or 500 FTU/kg of an Escherichia coli phytase (low-CP_EP and low-CPME_EP), respectively. Low-CP and low-CPME diets decreased (p < 0.01) the intake of feed as well as the protein and metabolizable energy conversion ratios in comparison to the control group. In general, phytases lowered (p < 0.01) the intake of feed, protein, and energy, but bacterial phytase showed a higher (p < 0.01) effect than A. niger one. The diets with low-CP and low-CPME levels decreased (p < 0.01) the amount of the excreta nitrogen. The supplementation of phytases had similar effects on digestibility of nutrients, carcass traits, bone mineralization and blood biochemistry. The supplementation of A. niger increased abdominal fat deposition of compared low-CPME diet compared to low-CPME_uns diet. All diets showed similar production index allowing the use of low-CPME diet when phytases was supplemented. Full article

Agricultural wastes are lignocellulosic biomasses that contain high mineral and nutrient contents. This waste can be used as a raw material in industrial enzyme production by microbial fermentation. Phytase is an important enzyme used in animal feed to enhance the amount of phosphorus available for the growth and overall health improvement of monogastric animals. Fungi offer high potential as an effective source in the production of various extracellular enzymes. In this study, the production of lignocellulolytic enzymes (endoglucanase and xylanase) and phytase by a thermophilic fungus, namely Thermoascus aurantiacus strain SL16W, was evaluated using sixteen different Thai agricultural forms of waste under conditions of high temperature (45 °C). Semi-solid state fermentation was used in the production experiments. The results of this study reveal that the highest phytase activity (58.6 U/g substrate) was found in rice bran, whereas the highest degrees of activity of endoglucanase and xylanase were observed in wheat bran and red tea leaves at 19 and 162 U/g substrate, respectively. Consequently, the optimal conditions for phytase production of this fungus using rice bran were investigated. The results indicate that the highest phytase yield (58.6 to 84.1 U/g substrate) was observed in rice bran containing 0.5% ammonium sulfate as a nitrogen source with 10 discs of inoculum size at a cultivation period of 9 days at 45 °C and moisture content of 95%. Notably, the phytase yield increased by 1.71-fold, while endoglucanase and xylanase were also increased by 1.69- and 1.12-fold, respectively. Furthermore, the crude enzyme obtained from the optimal condition was extracted. The crude enzyme extract was then separately added to red tea leaves, rice straw, corncobs, palm residue, and peanut husks. Subsequently, total reducing sugar and phosphorus contents were determined. The results indicate that the highest level of reducing sugar (122.6 mg/L) and phosphorus content (452.6 mg/L) (p < 0.05) were obtained in palm residue at 36 and 48 h, respectively, after the addition of the crude enzyme extract. This study has provided valuable information on a potentially eco-friendly way to valorize agricultural waste into value-added products as industrial enzymes. Full article