Rhizopus Oligosporus Research Articles

Improved nutritional value of surplus bread and perennial ryegrass via solid-state fermentation with Rhizopus oligosporus.

Solid-state fermentation (SSF) is a sustainable method to convert food waste and plant biomass into novel foods for human consumption. Surplus bread crusts (BC) have the structural capacity to serve as an SSF scaffold, and their nutritional value could be increased in combination with perennial ryegrass (PRG), a biorefining feedstock with high-quality protein but an unpleasant sensory profile. SSF with Rhizopus oligosporus was investigated with these substrates to determine if the overall nutritional value could be increased. The BC-PRG SSFs were conducted for up to 72 h, over which time the starch content had decreased by up to 89.6%, the total amino acid (AA) content increased by up to 141.9%, and the essential amino acid (EAA) content increased by up to 54.5%. The BC-PRG SSF demonstrated that this process could potentially valorise BC and PRG, both widely available but underexplored substrates, for the production of alternative proteins.

Study of decaffeination and business risk feasibility: Arabica and Robusta Arjuno coffee beans by anaerobic fermentation using Rhizopus oligosporus

Indonesia is the fourth largest coffee producer in the world. However, coffee is generally sold in its original form, even though the diversification products of coffee, such as decaffeinated coffee, have a higher selling price. One of the coffee-producing areas in Indonesia is Malang-East Java which has superior coffee commodities and does not yet have diversified products, such as Arjuno coffee (Arabica and Robusta) originating from the Mount Arjuno area. In this work, the decaffeination of Arabica and Robusta Arjuno coffee was conducted through anaerobic fermentation by Rhizopus oligosporus. An analysis of the business feasibility and production risk was also carried out. The results showed that caffeine content in the coffee significantly decreased with fermentation time. The caffeine content in Arabica and Robusta Arjuno coffee beans after 72 hrs of fermentation declined by 19.9% and 57.8% to 2.3% and 1.7%, respectively. Fermentation did not significantly change the physical of the beans but enriched the taste of coffee, where the flavor was strongly affected by the fermentation time. The analysis of the business feasibility and production risk showed that the decaffeinated Arabica and Robusta Arjuno coffee business provides a profit seven times higher than the existing coffee business.

New food ingredient via acid-tolerant Rhizopus oligorporus growth

As the global population grows, the consumption of unsustainably produced proteins increases. Researching sustainable food sources with a positive environmental impact is essential. This research provides valuable insights into the production and application of nutrient rich food sources. The potential of the biomass generated through fermentation with R. oligosporus was evaluated as a new protein source with low environmental impact. A fermentation method has been optimized to maximize the biomass production of R. oligosporus mycelium in solid-state and submerged-state fermentation, yielding 5.9 g dry weight/L and 5 g dry weight/L, respectively. The growth medium for these fungi was adapted to acid-tolerant (pH 4-3) conditions to create a food development environment that is more difficult for pathogens to thrive in, both in solid state and submerged state fermentation. The highest protein content obtained was 38.4 % wet weight by solid state fermentation. Fungal biomass exhibited techno-functional properties relevant to food product development tested both on pH 4 and pH 3, showing high water absorption and emulsifying activity, particularly in submerged fermentation at pH 3. In contrast, solid-state fermentation at pH 4 resulted in higher emulsion stability. This research demonstrates the potential of Rhizopus oligosporus as an acid-tolerant, high-quality protein ingredient with valuable functional properties. Its efficient production using minimal resources makes it a valuable asset for the food industry.

The enhancement of bioactive peptides, dietary polyphenols and antioxidant activity in Rhizopus Oligosporus fermented soybean tempeh through protein hydrolysis [pdf

The enhancement of bioactive peptides, dietary polyphenols and antioxidant activity in Rhizopus Oligosporus fermented soybean tempeh through protein hydrolysis [pdf

Nutritional Profile Analysis of Red Bean Tempeh Fermented Using <i>Rhizopus Oligosporus </i>at Different Time

Investigation of non-soybean legumes as raw material for making tempeh is very important to be carried out continuously considering soybean production tends to decline from year to year. This study aims to analyse the potential of red bean seeds as raw material for tempeh and changes in their nutritional profile when fermented at different fermentation times. The red beans were soaked in water overnight at room temperature and then boiled for 20 minutes. After boiling, the red beans were drained and then fermented for 36, 48, and 60 hours using a suspension of <i>Rhizopus oligosporus</i> with a weight of 2 g for each 1000 g of red beans. Red bean tempeh was analysed for quality using test parameters including physical appearance (color, texture, and aroma) and nutritional profile (calorie value, ash, water, crude fiber, fat, protein, and carbohydrate content). The physical appearance and nutritional profile of red bean tempeh were compared with those of soybean tempeh, while the quality of tempeh was compared with Indonesian national standards for tempeh. The results showed that the length of fermentation time significantly affected the nutritional profile of tempeh. Red bean tempeh fermented for 48 hours had a nutritional profile including energy, water, ash, protein, fat, carbohydrate, and crude fiber content of 201.59 kcal/100 g tempeh, 61.97%, 1.18%, 16.19%, 10.98%, 8.29%, and 1.13%, respectively. The physical appearance and nutritional profile of red bean tempeh have met the tempeh quality requirements issued by the Indonesian national standard for tempeh. Therefore, red bean seed appears to be as good as raw materials for tempeh production.

Potato peel as substrate for Single Cell Protein in animal feed by submerged fermentation

Single-cell protein (SCP) has gained attention in scientific research as a vital source of protein in animal feed and human food. Taking into account the importance of SCP, an attempt was made in the current research to grow Rhizopus oligosporus and Saccharomyces cerevisiae biomass by selecting potato peel as a substrate. The potato peel was treated with sulfuric acid to form potato peel hydrolysate following acid hydrolysis. In 1.0-L potato peel hydrolysate, 2.5-g/L KH2PO4, 0.5-g/L MgSO4, 0.5-g/L NaCl, and 10 g/L yeast extract were taken to prepare growth media. The moisture content of potato peel was examined by following standard procedure of the Association of Official Agricultural Chemists (AOAC). The Kjeldahl method was used to determine the protein content, and glucose was examined by using the dinitrosalicylic acid (DNS) method. Optimization of SCP yield was accomplished by following the ‘one factor at a time’ method. The effect of each parameter, such as incubation period, temperature and pH on SCP production was analyzed. Bioreactor scale-up production of SCP was performed in a jar fermenter. To enhance SCP, yield co-culture of Saccharomyces cerevisiae and Rhizopus oligosporus was used in a bioreactor that yielded 19 g/L of SCP. Thus, as a nutritional supplement for living organisms, SCP can effectively fulfill protein scarcity globally.

Solid-State Fermentation of Cereal Waste Improves the Bioavailability and Yield of Bacterial Cellulose Production by a Novacetimonas sp. Isolate.

Cereal wastes such as rice bran and cereal dust are valuable yet underutilised by-products of grain processing. This study aimed to bio-convert these wastes into bacterial cellulose (BC), an emerging sustainable and renewable biomaterial, via an inexpensive solid-state fermentation (SSF) pre-treatment using three mould isolates. Medium substitution by directly using untreated rice bran or cereal dust did not significantly increase the yield of bacterial cellulose produced by Novacetimonas sp. (NCBI accession number PP421219) compared to the standard Hestrin-Schramm (HS) medium. In contrast, rice bran fermented with Rhizopus oligosporus yielded the highest bacterial cellulose (1.55 ± 0.6 g/L dry weight) compared to the untreated control (0.45 ± 0.1 g/L dry weight), demonstrating an up to 22% increase in yield. Using the SSF process, the media production costs were reduced by up to 90% compared to the standard HS medium. Physicochemical characterisation using SEM, EDS, FTIR, XPS, XRD, and TGA was performed to gain insights into the internal structure, morphology, and chemical bonding of differently produced BC, which revealed comparable biopolymer properties between BC produced in standard and waste-based media. Hence, our findings demonstrate the effectiveness of fungal SSF for transforming abundant cereal waste into BC, providing a circular economy solution to reduce waste and convert it into by-products to enhance the sustainability of the cereal industry.

Exploring the Impact of Solid-State Fermentation on Fava Bean Flour: A Comparative Study of Aspergillus oryzae and Rhizopus oligosporus.

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.

Potato and dairy industry side streams as feedstock for fungal and plant cell cultures

Utilization of industrial side streams as nutrient source for cellular agriculture is a promising option to improve the sustainability of the production processes. The aim of the study was to evaluate usability of two liquid food industry side streams, potato cell fluid and acid whey, as nutrient source for production of food ingredients with plant cell cultures (arctic bramble (Rubus arcticus L.) and tobacco BY-2 (Nicotiana tabacum L.)) and filamentous fungi (Paecilomyces variotii, Rhizopus oligosporus and Trichoderma reesei). The side streams were found to contain various sugars and other potential nutrients suitable for the studied organisms. The side streams were used as a sole nutrient source (fungi) or as a replacement of selected nutrients in the growth media (fungi and plant cells) in flask scale cultivations. Acid whey was successfully used as a growth medium for filamentous fungi, but it inhibited plant cell growth presumably due to high organic acid content (14 g/l). Potato side stream was found suitable as a fungal and plant cell growth media supplement, and it was used together with glucose for filamentous fungi, or as a partial replacer of macronutrients for plant cells, in bioreactor cultivations yielding high fungal (up to 36 g/l dry weight) and good plant cell (9.5 g/l dry weight) biomass production. Analyses of the produced biomasses revealed good nutritional value in terms of amino acid (17–27 % of dry matter) and dietary fiber (23–30 % of dry matter) contents, giving good premises for utilization in human nutrition.

Assessment of Biochemical Potential of Rhizopus oligosporus as Starter Culture to Enhance the Nutritional Value of Palm Kernel Cake for Animal Feed Formulation

The objective of this study was to assess the biochemical potential of Rhizopus oligosporus as a starter culture to enhance the nutritional value of palm kernel cake (PKC) for animal feed formulation using appropriate standard methods. Among the experimental groups, the batch of birds fed with solid-state fermented PKC as a 50% maize replacement showed a noteworthy weight gain (p < 0.05) in relation to the control group, while the other experimental groups exhibited a weight loss. Serum levels of ALT, AST, ALP, creatinine, and blood urea did not show a notable difference from the reference group and those on the experimental diets. These findings collectively suggest that the pre-treatment of PKC using R. oligosporus holds the potential to elevate its nutritional quality for utilization in animal feed applications.

In vitro protein digestibility and mineral accessibility of edible filamentous Fungi cultivated in oat flour

Edible filamentous fungi, a source of mycoprotein, are one of the sustainable alternative protein. This study compares protein digestibility (DH%) and amino acid and mineral accessibility in Rhizopus oligosporus cultivated in oat flour (OatRO) or glucose media (GluRO) by using the INFOGEST in vitro digestion protocol. Fungal total amino acids was higher in GluRO (39.0 ± 1.1 % dw) than OatRO (21.8 ± 1.3 % dw) which was also the case for calcium and magnesium content. After completed gastrointestinal digestion, there were no significant differences between GluRO and OatRO regarding DH% (27.21 ± 10.4 % and 29.4 ± 0.5 %), however, GluRO provided significantly higher amino acid accessibility compared to OatRO (64.3 ± 1.6 % and 55.1 ± 3.1 %). Mineral accessibility of GluRO was for Ca: 37.9 ± 1.8 %, Zn: 9.3 ± 0.4 %, Fe: 38.2 ± 1.9 %, Mg: 66.5 ± 1.4 % and Cu: 24.7 ± 1.3 % and for OatRO; Ca: −40.2 ± 2.4 %, Zn: −4.13 ± 0.15 %, Fe:14.6 ± 1.6 %, Mg: 74.5 ± 3.1 %, and Cu: 55.95 ± 0.8 %. Despite the low phytic acid content, OatRO thus showed antinutrient properties with respect to calcium, and zinc, suggesting that oat-derived fungi had antinutrients other than phytic acid. This study hereby revealed that the cultivation substrate affect amino acid and mineral accessibility of filamentous fungi and calls for deeper evaluations of antinutrients in oat-derived fungi.

A fungus-based soil improvement using Rhizopus oryzae inoculum

This study demonstrates the efficacy of employing Rhizopus oryzae fungus inoculum as a potential solution to improve soil erodibility in coastal environments. A set of unconfined compression tests is conducted on Miami Beach sand treated with a R. oryzae inoculum. Our findings suggest that the R. oryzae fungus inoculum effectively improves the stability of sand by acting as a natural binding agent. This finding aligns with previous studies that utilized different Rhizopus species, such as Rhizopus oligosporus, to improve sand properties. However, a notable difference is observed; the R. oryzae-treated sand exhibits remarkable durability, maintaining significant strength over an extended period without water or dietary supply. The durability is likely attributable to the morphological characteristics of R. oryzae that extensively branches its mycelial network. This paper shares the new discovery to the bio-geotechnics research community, potentially allowing for the customization of soil improvement process by choosing between the fast-acting R. oligosporus and the longer-lasting R. oryzae.

Microbiological, sensory, and chemical properties of high-quality tempeh made with instant Mosaccha tempeh inoculum powder.

The combination of Saccharomyces cerevisiae and Rhizopus oligosporus liquid inoculum has been successfully used to ferment soybeans into tempeh that contains β-glucan. However, using the liquid inoculum of these two microbes as a starter is impractical; so, developing an instant tempeh dry inoculum in powdered form, called the Mosaccha inoculum powder, for ease of use is necessary. This study aimed to determine the best concentration of instant Mosaccha inoculum powder to produce high-quality Mosaccha tempeh. The study used a Complete Randomized Block Design with seven different levels of instant Mosaccha inoculum powder percentage, ranging from 0.3% to 1.8% (w/w). A commercial tempeh inoculum, RAPRIMA, amounting to 0.2%, was used as control. Then, the microbiological (total mold and total yeast) and sensory (color, aroma, texture, and taste) properties were evaluated. The data obtained was analyzed statistically using analysis of variance (ANOVA) and Honestly Significant Difference (HSD) tests at the 5% level. The results showed that the percentage of instant Mosaccha inoculum powder significantly affected the microbiological and sensory properties of Mosaccha tempeh. A concentration of Mosaccha inoculum powder between 0.6% to 1.8% could produce good quality Mosaccha tempeh, but the best Mosaccha tempeh was produced with 1.5% instant Mosaccha inoculum powder, which met the Indonesian National Standards (SNI) 3144:2015, had a very favorable taste, and contained 0.49% β-glucan. Therefore, Mosaccha inoculum in powdered form can be developed and used as a starter in making high-quality tempeh that contains β-glucan.

Solid-State Fermentation of Quinoa Flour: An In-Depth Analysis of Ingredient Characteristics

Plant protein ingredients are gaining attention for human nutrition, yet they differ significantly from animal proteins in functionality and nutrition. Fungal solid-state fermentation (SSF) can modulate the composition and functionality, increasing their applicability in foods. Quinoa flour (QF) served as a substrate for Aspergillus oryzae and Rhizopus oligosporus, resulting in two fermented ingredients (QFA and QFR) with different nutritional, functional, and aroma characteristics. A higher increase in protein (+35%) and nitrogen (+24%) was observed in the QFA, while fat was predominantly increased in the QFR (+78%). Fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) decreased in the QFR but increased in the QFA due to polyol production. Metabolomic analysis revealed higher lactic acid concentrations in the QFA, and higher citric, malic, and fumaric acid contents in the QFR. The SSF reduced most antinutrients, while R. oligosporus produced saponins. Olfactometry showed the development of fruity ester compounds and a decrease in metallic and cardboard aromas. Both ingredients showed an enhanced water-holding capacity, with the QFA also demonstrating an increased oil-holding capacity. Complex formation increased the particle size, reduced the solubility, and decreased the foaming properties. Mycelium production darkened the ingredients, with the QFR having a higher differential colour index. This study highlights the potential of SSF to produce ingredients with improved nutritional, sensory, and functional properties.

Effects of yeast variations and fermentation time on the physicochemical characteristics and sensory quality of sorghum soy sauce

Abstract Soy sauce is a traditional salty liquid condiment produced by fermenting soybeans. However, the increasingly high price of soybeans on the market has led to the need for alternative substitutes to the raw material for making soy sauce. Sorghum (Sorghum bicolor (L.) Moench.) is a cereal crop that is widely grown in Indonesia and has high carbohydrate and protein content but has yet to be utilized optimally, so sorghum has the potential to be used as a functional. The sensory quality of soy sauce is affected by the fermentation process. This research aims to analyze the effect of adding yeast variations and fermentation time on the physicochemical and sensory quality characteristics of sorghum soy sauce. The research method used a wholly randomized factorial design with three repetitions. The first factor is yeast variations, which use two levels, Rhizopus oligosporus and Saccharomyces cerevisiae. The second factor is the fermentation time, with four levels, namely 7, 11, 15, and 19 days. The resulting soy sauce is then analyzed for protein content, acidity, viscosity, and sensory analysis using the attributes of taste, color, and flavor. The data obtained was processed with SPSS software using two-way ANOVA and Least Significant Difference (LSD) if the results obtained had a significant effect. The research results showed that the use of various types of yeast has a substantial impact on the protein content, viscosity, and flavor attributes of sorghum soy sauce. Meanwhile, fermentation time treatment had a significant effect on acidity and color. Overall, the best treatment was obtained by adding Saccharomyces cerevisiae with a fermentation time of 11 days, resulting in a protein content of 1.32%, acidity of 4.60, and viscosity of 3.11 cp. Sensory analysis showed that the best treatment was soy sauce fermentation using Rhizopus oligosporus for 11 days, which obtained a taste attribute value of 3.24, flavor value of 2.21, and color value of 3.96.

Investigation of Rhizopus oligosporus Metabolites in Fermented Wheat Bran and Its Bio Function in Alleviating Colitis in Mice Model.

Wheat bran (WB) is a low-value by-product of the wheat milling industry. Solid-state fermentation with Rhizopus oligosporus is performed to improve WB's nutritional quality (RH). Twenty-five mice (11-week-old C57BL/6N male mice) were divided into three groups. The first group was fed a control diet (n = 8), the second group a 10% WB-supplemented diet (n = 8), and the last group had a 10% RH-supplemented diet (n = 9). The diet treatment was administered for 4 days before dextran sodium sulfate (DSS, 3% in drinking water) was administered for 9 days. RH supplementation prevented bodyweight loss and reduced the disease activity index in mice. An increase in the level of SCFAs in mouse intestines was detected post-RH supplementation, suggesting that SCFAs might have contributed to its anti-colitis effect. Metabolome analysis was conducted to explore other bioactive compounds in RH. R. oligosporus fermentation significantly increased the amounts of ergothioneine, arginine, branched-chain amino acids, and adenosine in wheat bran. All of these compounds are known to have antioxidant and anti-inflammatory capacities. These bioactive compounds might also have contributed to the RH's ability to ameliorate DSS-induced colitis.

Fungi as a Sustainable Solution for Heavy Metal Removal in Wastewater Treatment

This study investigates the ability of non-living fungal biomass from Aspergillus terreus, Rhizopus oligosporus, and Rhizopus arrhizus to reduce heavy metal concentrations in wastewater. Using non-living fungal blocks, the experiment targeted the removal of lead (0.70 ppm), cadmium (0.110 ppm), and copper (0.80 ppm) from wastewater at the Al-Dur district sewage treatment station. Conducted under controlled conditions (25 degrees Celsius, pH 6.5-7.6) over a 24-hour period, the results demonstrated significant reductions in metal concentrations, with statistical significance at P<0.01. These findings suggest that non-living fungal biomass could be a cost-effective and environmentally friendly alternative for heavy metal remediation in wastewater treatment. Highlights: Fungal biomass effectively reduces lead, cadmium, copper quickly. Results statistically significant, demonstrating reliability. Sustainable, cost-effective alternative to chemical treatments. Keywords: Heavy Elements, Aspergillus Terries, Rhizopus Oligosporium, Fungal Biosorption, Non-Living Biomass

Tempeh source of vegetable protein: nutritional composition and health benefits

Tempeh is a food native to Indonesia obtained from the controlled fermentation of soybeans by the fungus Rhizopus oligosporus. This Southeast Asian food is increasingly becoming an inexpensive substitute for meat due to its excellent nutritional profile. This review presents the most relevant aspects of the history of tempeh, the current regulation and explains the changes in soybeans' nutritional composition after the enzymatic action of the fungus. The review describes the nutritional composition and the health benefits derived from its consumption.

In vitro protein digestion and carbohydrate colon fermentation of microbial biomass samples from bacterial, filamentous fungus and yeast sources

This study evaluated the nutritional quality of different microbial biomass samples by assessing their protein digestibility and carbohydrate fermentability in the colon using in vitro methods. Four microbial samples were produced: one hydrogen-oxidizing bacterial strain (Nocardioides nitrophenolicus KGS-27), two strains of filamentous fungi (Rhizopus oligosporus and Paecilomyces variotii), and one yeast strain (Rhodotorula babjevae). The microorganisms were grown in bioreactors, harvested and dried before analysis. The commercial fungal product Quorn was used as a reference. The protein digestibility of the microbial samples was analysed using the INFOGEST in vitro model, followed by quantification of N-terminal amine groups. An in vitro faecal fermentation experiment was also performed to evaluate the degradation of carbohydrates in microbial biomass samples and formation of short-chain fatty acids (SCFA). The fungal biomass samples had higher protein hydrolysis (60–75 %) than the bacterial sample (12 %) and Quorn (45 %), while the yeast biomass had the highest protein digestibility (85 %). Heat-treatment of the biomass significantly reduced its protein digestibility. Total dietary fibre (DF) content of fungal biomass was 31 – 43 %(DW), mostly insoluble, whereas the bacterial biomass contained mainly soluble DF (total DF: 25.7 %, of which 23.5 % were soluble and 2.2 % insoluble). After 24 h of colonic in vitro fermentation, SCFA production from the biomass of Paecilomyces, Quorn and Rhodotorula was similar to that of wheat bran, while 17 % and 32 % less SCFA were produced from the biomass of Rhizopus and the bacterial strain, respectively. Further studies are needed to clarify the reasons for the observed differences in protein digestibility and DF fermentability, especially regarding the cell wall structures and role of post-processing.

Enhancement of the bioactive compounds and biological activities of maca (Lepidium meyenii) via solid-state fermentation with Rhizopus oligosporus

Maca (Lepidium meyenii Walp) is renowned for its phytochemicals, including amino acids, saponins, and macamides, confer nutritional and medicinal benefits. This study analyzed the bioactive constituents of maca via solid-state fermentation with Rhizopus oligosporus for 0–15 days. After fermentation, the l-carnitine content reached 157.3 μg/g. A 93% increase in macamide B was recorded after 7-day fermentation. Total flavonoid and saponin contents increased by 88.2% and 110.3%, respectively. The fermentation process significantly enhanced the physicochemical attributes of maca; in particular, its water retention and cholesterol-binding capacities increased by 1.73- and 4.30-fold, respectively, compared with the non-fermented maca. Moreover, fermented maca exhibited stronger antioxidant and α-glucosidase-inhibiting effects than non-fermented maca. Finally, the neuroprotective effect of maca on HT-22 cells increased by 23% after 5-day fermentation. These findings demonstrate the potential of fermented maca as a novel ingredient for foods, beverages, and pharmaceuticals.