Search Results (108)

The objective of this study was the evaluation of fungal solid-state fermentation (SSF) for the production of alginate lyase and extraction of uronic acids from Sargassum sp. For this purpose, the fungi Trichoderma asperellum, Aspergillus oryzae, and Rhizopus oryzae were applied (alone or combined) to Sargassum sp. biomass through SSF (10⁷ spores g_biomass⁻¹, 30 °C, and 7 days of treatment). In general, individual SSF with all three fungi degraded the biomass, achieving a marked synergy in the production of cellulase, laminarinase, and alginate lyase activities (especially for the last one). Trichoderma was the most efficient species in producing laminarinase, whereas Rhizophus was the best option for producing alginate lyase. However, when dual combinations were tested, the maximal values of alginate lyase activities were reached (13.4 ± 0.2 IU g_biomass⁻¹ for Aspergillus oryzae and Rhizopus oryzae). Remarkably, uronic acids were the main monomeric units from algal biomass solubilization, achieving a maximum yield of 14.4 mg_uronic g_biomass⁻¹, with the A + R condition being a feasible, eco-friendly alternative to chemical extraction of this monomer. Additionally, the application of all the fungal pretreatments drastically decreased the total phenolic content (TPC) in the biomass from 369 mg L⁻¹ to values around 44–84 mg L⁻¹, minimizing the inhibition for possible subsequent biological processes in which the residual solid can be used. Full article

Spent coffee grounds are the most abundant waste generated during the preparation of coffee beverages, amounting to 60 million tons per year worldwide. Excessive food waste production has become a global issue, emphasizing the need for waste valorization through the bioprocess of solid-state fermentation (SSF) for high added-value compounds. This work aims to identify the operational conditions for optimizing the solid-state fermentation process of spent coffee grounds to recover bioactive compounds (as polyphenols). An SSF process was performed using two filamentous fungi (Trichoderma harzianum and Rhizopus oryzae). An exploratory design based on the Hunter & Hunter method was applied to analyze the effects of key parameters such as inoculum size (spores/mL), humidity (%), and temperature (°C). Subsequently, a Box–Behnken experimental design was carried out to recovery of total polyphenols. DPPH, ABTS, and FRAP assays evaluated antioxidant activity. The maximum concentration of polyphenols was observed in treatment T3 (0.279 ± 0.002 TPC mg/g SCG) using T. harzianum, and a similar result was obtained with R. oryzae in the same treatment (0.250 ± 0.011 TPC mg/g SCG). In the Box–Behnken design, the most efficient treatment for T. harzianum was T12 (0.511 ± 0.017 TPC mg/g SCG), and for R. oryzae, T9 (0.636 ± 0.003 TPC mg/g SCG). These extracts could have applications in the food industry to improve preservation and functionality. Full article

Poly(ε-caprolactone) (PCL) is a synthetic plastic known for its excellent physicochemical properties and a wide range of applications in packaging, coatings, foaming, and agriculture. In medicine, its versatility allows it to function as a scaffold for drug delivery, sutures, implants, tissue engineering, and 3D printing. In addition to its biocompatibility, PCL’s most notable characteristic is its biodegradability. However, this property is affected by temperature, microbial activity, and environmental conditions, which means PCL can sometimes remain in nature for long periods. This review shows that various types of microorganisms can efficiently degrade PCL, including different strains of Pseudomonas spp., Streptomyces spp., Alcaligenes faecalis, and fungi like Aspergillus oryzae, Fusarium spp., Rhizopus delemar, and Thermomyces lanuginosus. These microorganisms produce enzymes such as lipases, esterases, and cutinases that break down PCL into smaller molecules that act as substrates. The review also examines the phylogenetic diversity of organisms capable of biodegrading PCL, the biochemical pathways involved in this process, and specific aspects of the genetic framework responsible for the expression of the enzymes that facilitate degradation. Targeted research on microbial PCL biodegradation and its practical applications could significantly aid in reducing and managing plastic waste on a global ecological scale. Full article

β-glucans from filamentous fungi are important for human health. There is limited research on polysaccharides from filamentous fungi, and no reports have been published regarding the optimization of culture media to produce β-glucans from Rhizopus oryzae using liquid waste from potato starch processing. In this regard, the fermentation conditions to produce β-glucans from Rhizopus oryzae M10A1 were optimized using the one variable at a time (OVAT) and response surface methodology (RSM). The β-glucans were chemically characterized by determining moisture, nitrogen, protein, fat, ash, and total carbohydrates. The color, molecular weight, β-glucan content, monosaccharide composition, and structural and conformational characteristics were assessed by colorimetry, gel permeation chromatography, high-performance liquid chromatography, and Fourier transform infrared spectroscopy, respectively. The microbial indicators, mesophilic aerobes, molds, yeasts, and Escherichia coli were quantified following ISO standard protocols. Optimization indicated that supplementation with 0.8% (w/v) glucose and ammonium sulfate enhanced heteroglycan production (3254.56 mg/100 g of biomass). The β-glucans exhibited high purity, a light brown color, a molecular weight of 450 kDa, and a composition predominantly consisting of glucose and galactose. These findings suggest that β-glucans from Rhizopus oryzae M10A1 could be used for food and health applications. Full article

The solid-state fermentation (SSF) of agro-industrial by-products such as okara, pomegranate peel, and cranberry pomace presents a sustainable approach to enhance the release of bioactive compounds. This study investigated the effects of different microbial cultures—Rhizopus oligosporus, Aspergillus oryzae, Streptococcus thermophilus, and a co-culture of R. oligosporus and S. thermophilus—on the bioconversion of bioactive compounds in 100% okara, okara with 2% pomegranate peel, and okara with 1% cranberry pomace. The objective was to assess whether co-culture fermentation with molds and S. thermophilus augments the release of bioactive compounds in okara-based fermentations through synergistic enzymatic activity. Over a period of 72 h, isoflavone transformation (daidzin, daidzein, genistin, and genistein), pH evolution, and water activity were assessed. The co-culture system exhibited improved bioconversion, leading to significant (p < 0.01) increases in daidzein and genistein in pure okara compared to the starting material. The highest polyphenol content (0.908 mg/g) and antioxidant capacity (24.9 mg Trolox eq/g) were recorded in 100% okara. However, pomegranate peel inhibited β-glucosidase activity, delaying the release of isoflavone aglycones. These findings confirm that co-culture fermentation is an effective strategy for enhancing the bioactive properties of okara-based fermentations. This facilitates the release of bioactive aglycones and supports the upcycling of agro-industrial by-products into functional food ingredients. Future research should focus on optimizing fermentation parameters to further enhance the release of bioactive compounds. Full article

In the present study, the strain Rhizopus oryzae EMM was isolated from germinated autochthonous red maize seeds, which were harvested in a region of San Diego-Buenavista, Papalotla, Tlaxcala, Mexico, where cobs with fungal infections have been observed. This fungal strain caused wilting in the maize seedlings. Pseudomonas protegens EMM-1 was tested for its ability to inhibit R. oryzae EMM, both in culture media and in association with maize plantlets. P. protegens EMM-1 inhibited the growth of R. oryzae EMM under all culture media conditions explored. The ability of P. protegens EMM-1 to inhibit the growth of R. oryzae EMM associated with plants was evaluated in both a hydroponic system and in vermiculite. In both systems, P. protegens EMM-1 strongly inhibited the growth of R. oryzae EMM. The dry weight of root plants infected with R. oryzae EMM and inoculated with P. protegens EMM-1 increased to 0.43 g, while that of plants infected only with R. oryzae EMM reached just 0.19 g under hydroponic conditions. However, no differences were observed under vermiculite conditions. The dry weight of the aerial region of plants infected with R. oryzae EMM and inoculated with P. protegens EMM-1 was greater than that of plants infected only with R. oryzae EMM, both under hydroponic and vermiculite conditions. These results indicate that P. protegens EMM-1 inhibits the infection caused by R. oryzae EMM, thereby improving plant growth. Moreover, the genome analysis of P. protegens EMM-1 revealed the presence of several genes that potentially encode for antimicrobial compounds, which could strengthen the potential use of P. protegens EMM-1 as a biocontrol agent in maize plants. Full article

The growing aquaculture industry has an increasing demand for novel, sustainably produced protein sources for aquafeed. This study aimed to determine the apparent digestibility (AD%), pellet quality, and protein score of four novel fungal proteins in rainbow trout (Oncorhynchus mykiss), namely, PEKILO^® (PEK) derived from Paecilomyces variotii, Aspergillus oryzae (AO), Rhizopus oligosporus (RO), and Rhizopus delemar (RD). All fungi were grown on various side-streams, such as beet vinasse, thin stillage, and whole stillage. The diets were produced by extrusion technology and consisted of control and test diets with a 30:70 test ingredient/control ratio. Feeding lasted for 39 days. Each tank had 20 fish, with three replicates per dietary treatment. One-way ANOVA was performed to compare the means of the groups with each other. The dry matter (DM) digestibility of PEK was significantly higher than that of AO, RD, and RO, all with similar digestibility. The crude protein AD% for PEK was 86.5%, which is significantly higher than that of the other fungal sources. AO, PEK, RD, and RO had similar crude fat AD% compared to each other, at 83.8%, 87.4%, 90.5%, and 88.5%, respectively. The pellet quality was found to deteriorate with addition of fungal proteins. PEK had high AD% for most of the macronutrients tested and better pellet quality. Full article

Corn, a widely cultivated cereal, is a rich source of several antioxidant compounds, including phenolic compounds. Some of these compounds are bound within the components of the corn cell wall, requiring specific treatments to release them. Solid-state fermentation (SSF) using Rhizopus oryzae enhanced the antioxidant capacity and phenolic content in legumes and grains. However, there is limited information regarding its application in blue corn. This study aimed to evaluate the effect of R. oryzae growth on the phenolic content and antioxidant capacity of blue corn kernels. The results demonstrated that R. oryzae used blue corn kernels for growth, which led to an increase in free phenolic compounds, reaching their highest concentration at 60 h of culture. Compared to the unfermented control (0 h), SSF increased by up to 161% in total phenolic content and a 94% increase in antioxidant capacity. The main phenolic compounds identified in the blue corn extracts at 60 h using RP-HPLC-ESI-MS included caffeic acid 4-O-glucoside, rosmanol, p-coumaroyl tartaric acid glucosidic ester, 5-heptadecylresorcinol, and caffeoyl tartaric acid. The SSF represents an eco-friendly method for enhancing the antioxidant capacity and phenolic compounds of blue corn grain. Full article

Rice (Oryza sativa L.) is a staple food globally, providing a critical food for the majority of the Asian population. However, it exposes risks during post-harvest storage, threatening substantial losses in rice quality and quantity. Hence, this study developed a cinnamon oil–chitosan:gelatin film (CO–C:G film) with the parameters as the chitosan:gelatin ratio (C:G = 1:1 and 1:2), cinnamon oil (CO) contents (0.75, 1.0, 1.25, 2.5, and 5.0%) and thickness film levels (0.165, 0.183, and 0.287 mm) to inhibit three fungal species, Rhizopus oryzae 01, R. microsporus 01, and Syncephalastrum racemosum 01, and control rice weevil infestation on paddy rice at a variety of water activities, such as 0.71 a_w and 0.95 a_w, at room temperature. The results revealed that at 0.95 a_w, the fungal growth rate and rice weevil’s mortality were impacted significantly by all parameters of the CO–C:G film (p < 0.05). Especially, the CO–C:G film with 1.25% CO and C:G = 1:1 at a thickness film of 0.287 mm inhibited all observed fungi and rice weevils better than the CO–C:G film’s other parameters. The inhibition of the CO–C:G film for these fungi ranged from 66% to 72.6%. Likewise, 80–100% of rice weevils were mortal when paddy rice was treated with the CO–C:G film on the 12th or 15th day of treatment depending on the water activity of paddy rice grains. The findings of this study provide insights for researchers, agricultural experts, and the food industry, highlighting the need to establish effective and sustainable strategies for rice preservation. Full article

We present the case of a 60-year-old immunocompromised man who presented with two pruritic pink–red indurated nodules with overlying scale and focal areas of ulceration on his left dorsal and left medial forearm, which evolved over a 2-month period. The pathology showed numerous fungal hyphae present that were pauci-septate with various branched angles and variable hyphal thickness. Fungal cultures grew Rhizopus species and a universal fungal PCR detected the Rhizopus oryzae complex. Based on the clinicopathologic correlation, the diagnosis of cutaneous mucormycosis was made. Cutaneous mucormycosis is an aggressive fungal infection of the Mucorales family occurring after the inoculation of fungal spores in disrupted skin. It usually presents as a necrotic eschar but can also present as cellulitis that evolves into a necrotic ulcer. A prompt diagnosis is critical for the effective management of cutaneous mucormycosis. The treatment includes an immediate systemic treatment with amphotericin B and a surgical debridement of the necrotic regions. Given the wide range of presenting symptoms, clinical suspicion for this emergent condition must remain high in immunocompromised and diabetic patients. Full article

Triacylglycerols containing medium-chain fatty acids at the sn-1,3 positions and a long-chain fatty acid at the sn-2 position (MLM-TAG) are of nutritional interest. However, they are scarce in common food sources and are usually synthesized by chemical or enzymatic methods. In this work, the enzymatic synthesis of MLM-TAG was attempted using sn-2 monoacylglycerols (sn-2 MAG) from the ethanolysis of an arachidonic acid-rich fraction from ARASCO and fatty acid ethyl esters from the ethanolysis of coconut oil as substrates. The highest yield of sn-2 MAG (23.3 mol%) was obtained after 1 h of ethanolysis with Novozym 435 lipase at 25 °C, and the best profile of the ethanolysis products of coconut oil was obtained after 24 h of reaction catalyzed by the lipase from Thermomyces lanuginosus. Regarding the enzymatic synthesis of structured TAG, the lipase from Rhizopus oryzae gave better results than those from Thermomyces lanuginosus and Rhizomucor miehei, with the sn-2 position mainly esterified with arachidonic acid (34.8%) and the sn-1,3 positions mainly esterified with capric and lauric acids (35.1%). This work focuses on a simple process for the enzymatic production of structured TAG without prior purification of the sn-2 MAG. Full article

Solid-state fermentation (SSF) has emerged as an effective method for wheat bran valorization, providing advantages like cost reduction, decreased water usage, and enhanced product quality. In this study, wheat bran was fermented using Rhizopus oryzae to evaluate the extraction yield of soluble dietary fiber, the activities of protease and amylase, and the physicochemical characteristics of wheat bran during SSF. The findings demonstrated that the maximum yield of soluble dietary fiber was achieved after 120 h of fermentation at a moisture content of 55%. Simultaneously, protease activity peaked at 45% moisture content after 120 h, while amylase activity was maximized at 55% moisture content after 96 h. The microstructure result indicated that most of the starch granules degraded after 144 h of fermentation at a moisture content of 55%, exhibiting a smooth outer layer of wheat bran. Furthermore, fermented bran showed a significant rise in total phenols, peaking at 96 h at a moisture content of 55%. Flavonoid content also reached its maximum after 72 h of fermentation at 55% moisture content. The content of alkylresorcinols in fermented wheat bran changed slightly under different moisture content and fermentation time conditions, which was consistent with the change in pH value. The DPPH radical scavenging rate was optimal when the moisture content was 55% after 96 h. The ABTS radical scavenging rate, hydroxyl radical scavenging rate, and reducing ability were optimal at 55% moisture content after 120 h. These findings demonstrate that the optimal conditions for the SSF of wheat bran using Rhizopus oryzae involve maintaining the moisture at 55%, suggesting that this method is effective for enhancing the value of wheat bran. Full article

Along with the development of technology and the increasing consumption of polymeric materials, which have become an integral part of man’s everyday life, problems related to their disposal are arising. The presented research concentrates on the studies on the enzymatic degradation of selected epoxy-polyurethane materials filled with 2 or 5 wt.% of waste unmodified or chemically modified through mercerization wood flour. Composites, subjected to the degradation process, contained up to 60% of raw materials of natural origin. The enzymatic degradation was carried out for 28 days, in three environmental conditions, differing in the type of applied buffer, pH, process temperature, the amount, and the type of applied enzyme. In this study, the influence of two lipases was tested (specifically: lipase of microbiological origin—Rhizopus Oryzae Lipase, and one of animal origin—Porcine Pancreas Lipase). There were seven compositions tested, based on the polyaddition product of epoxidized soybean oil with bisphenol A, differing in the amount of filler and the type of modification to which wood flour was subjected before the application in the polymer composite. After enzymatic degradation, the greatest progress of biodegradation was observed at T = 30 °C, in a complex phosphate buffer with pH = 6.8, in the presence of the Porcine Pancreas enzyme. Under these conditions, a slightly smaller effect was also observed in the presence of the Rhizopus Oryzae enzyme. At the same time, the compositions containing mercerized wood flour turned out to be the most susceptible to biodegradation with the above-mentioned enzymes. After conducting the process in the full 4-week cycle numerous changes were noticed within the tested sample, such as (1) 7.0 %wt. of the overall weight loss of samples, (2) reducing the value of the static contact angle (e.g., from 116.7° before degradation to 27.2° at the end of the study), and (3) morphological appearance of the sample (sample’s surface had suffered erosion noticed as smoothest roughnesses and numerous empty holes throughout its entire volume), concerning sample’s condition before enzymatic degradation. Full article

Fava bean (Vicia faba L.) is a protein-rich pulse with high nutritional value, but its functional and sensory characteristics limit its application in foods. Solid-state fermentation (SSF) can modify the composition of plant proteins, modulate its functionality, and enhance the sensory aspects. In this study, fava bean flour (FB) was fermented with Aspergillus oryzae and Rhizopus oligosporus to produce FBA and FBR, respectively, ingredients with distinct nutritional, functional, and aroma characteristics. The protein content increased by 20% in FBA and 8% in FBR, while fat levels rose more significantly in FBR (+40%). The overall content of fermentable oligo-, di-, mono-saccharides, and polyols (FODMAPs) decreased by 47% (FBA) and 57% (FBR), although polyol production by A. oryzae was observed. SSF improved the nutritional profile of FBA and FBR, with a notable increase in the concentration of essential amino acids observed, and a reduction in most antinutrients, with the exception of trypsin inhibitors. SSF resulted in the formation of aggregates, which increased the particle size and reduced protein solubility. Emulsions prepared with the fermented ingredients separated faster, and the foaming capacity of both FBA and FBR was decreased, but an increase in water-holding capacity was observed. SSF resulted in the production of predominantly savoury-associated aroma compounds, with compounds characteristic of metallic and mouldy aromas reduced. These results indicate the potential of SSF to transform FB with enhanced nutritional value and improved sensory and functional properties. Full article

Grain processing produces many by-products, including wheat bran, wheat germ and rice bran, which are rich in carbohydrates, proteins and trace elements. In this study, these grain-derived by-products were used as raw materials to conduct solid-state fermentation using mixed strains of Aspergillus kawachii and Rhizopus oryzae, and the potential immunomodulatory and anti-allergic properties of fermented product were evaluated. Solid-state fermentation of a grain by-product mixture, consisting of rice bran, wheat bran, and wheat germ in a 2:1:1 weight ratio, using both A. kawachii L1 and R. oryzae L1 at 26 °C for 5 days, significantly increased the total phenolic, flavonoid, and amino acid contents. The anti-allergic activity of aqueous extract of the fermented product was evaluated in murine models of food allergy and delayed-type hypersensitivity. Oral administration of the fermented product extract (100–200 mg/kg) notably alleviated allergic symptoms such as diarrhea and histopathological changes in the intestines. Moreover, the extract effectively reduced allergen-specific serum antibodies, suppressed splenic cytokine secretion, and mitigated tissue edema and inflammation induced by allergens. Importantly, the extract induced the production of IL-10 and TGF-β, which are well-known cytokines primarily secreted by regulatory T cells. These results underscore the promising immunomodulatory effects of A. kawachii and R. oryzae fermented grain product, suggesting their potential as functional foods or additives for managing allergic disorders, with implications for future therapeutic and dietary applications. Full article