Solid State Fermentation Method Research Articles

Lipolytic production from solid-state fermentation of the filamentous fungus Penicillium polonicum and its applicability as biocatalyst in the synthesis of ethyl oleate.

Lipases represent versatile biocatalysts extensively employed in transesterification reactions for ester production. Ethyl oleate holds significance in biodiesel production, serving as a sustainable alternative to petroleum-derived diesel. In this study, our goal was to prospect lipase and assess its efficacy as a biocatalyst for ethyl oleate synthesis. For quantitative analysis, a base medium supplemented with Rhodamine B, olive oil, and Tween 80 was used. Solid-state fermentation utilized crambe seeds of varying particle sizes and humidity levels as substrates. In the synthesis of ethyl oleate, molar ratios of 1:3, 1:6, and 1:9, along with a total enzymatic activity of 60 U in n-heptane, were utilized at temperatures of 30°C, 37°C, and 44°C. Reactions were conducted in a shaker at 200rpm for 60min. As a result, we first identified Penicillium polonicum and employed the method of solid-state fermentation using crambe seeds as a substrate to produce lipase. Our findings revealed heightened lipolytic activity (22.5 Ug-1) after 96h of fermentation using crambe cake as the substrate. Optimal results were achieved with crambe seeds at a granulometry of 0.6mm and a fermentation medium humidity of 60%. Additionally, electron microscopy suggested the immobilization of lipase in the substrate, enabling enzyme reuse for up to 4 cycles with 100% enzymatic activity. Subsequently, we conducted applicability tests of biocatalysts for ethyl oleate synthesis, optimizing parameters such as the acid/alcohol molar ratio, temperature, and reaction time. We attained 100% conversion within 30min at 37°C, and our results indicated that the molar ratio proportion did not significantly influence the outcome. These findings provide a methodological alternative for the utilization of biocatalysts in ethyl oleate synthesis.

Employing soil isolated fungi for production of bioactive phenolic compounds: a fermentative approach

An efficient method of solid-state fermentation (SSF) is reported for producing bioactive phenolic compounds using soil-isolated fungi. Antioxidant activity using a rapid DPPH (1,1-diphenyl-2-picryl hydrazyl), was employed to screen the 120 fungal isolates from soil. Aspergillus terreus 1, Aspergillus fumigatus, Aspergillus terreus 2, Penicillium citrinum, Aspergillus wentii1, Aspergillus wentii 2, Penicillium expansum and Penicillium granulatum were chosen, concerning their antioxidant activity and total phenolic content. These fungal strains were applied on agro residues viz. sugarcane bagasse, corn cob, rice straw, pea pod and wheat straw, to evaluate the release of phenolic compounds. The fermented extracts from various agro-residues showed good antioxidant activity against DPPH, ferric ion, and nitric oxide radicals. The highest antioxidant activity was observed in fermented extracts of sugarcane bagasse, followed by pea pod. Additionally, the total phenolic content in the fermented extracts positively correlated with antioxidant potential. This study highlights the significant potential of solid substrate fermentation using soil-isolated fungi and agro-residues to produce bioactive phenolic compounds with potent antioxidant properties. The utilization of SSF for the extraction of bioactive compounds from natural sources not only offers a clean and sustainable approach but also contributes to the valorization of agro-industrial residues.

Impact of Fermentation on Hyptolide and Phytochemical Composition of Hyptis pectinata (L.) Poit

Solid State Fermentation has been employed for the biotransformation of the herbal plant Hyptis pectinata (L.) Poit is widely distributed in tropical regions of Brazil and is also present in Indonesia. The plant has been used to treat anti-inflammatory, anti-cancer, bacterial infection, and wound healing. This study aims to investigate the effects of using a solid-state fermentation method to ferment the leaves of Hyptis pectinata (L.) Poit towards the composition of phytochemicals and hyptolides. This study was carried out in several stages, including fermentation of Aspergillus niger leaves, sample extraction with methanol, determination of total phenolic and total triterpenoid content, phytochemical screening, and analysis of hyptolide using HPLC. The research results showed the growth of Aspergillus niger on the leaves of Hyptis pectinata (L.) Poit got into the logarithmic phase at 36 hours. Triterpenes and phenolics were present in the phytochemical profile, while alkaloids, tannins, and flavonoids were absent. The total phenolic and triterpenoid content increased by 33.68% and 17.78% respectively. HPLC analysis showed a decrease in hyptolide content in the fermented product. These results indicate the potential of fermented Hyptis pectinata (L.) Poit as an additional cancer therapy.

Preparation of glucoamylase microcapsule beads and application in solid-state fermentation.

Baijiu brewing adopts the solid-state fermentation method, using starchy raw materials, Jiuqu as saccharifying fermenting agent, and distilled spirits made by digestion, saccharification, fermentation and distillation. In the late stages of solid-state fermentation of Baijiu, the reduced activity of glucoamylase leads to higher residual starch content in the Jiupei, which affects the liquor yield. The direct addition of exogenous glucoamylase leads to problems such as the temperature of the fermentation environment rising too quickly, seriously affecting the growth of microorganisms. To solve the problem of reduced activity of glucoamylase in the late stage of solid-state fermentation of Baijiu, microcapsule beads (M-B) based on microcapsule emulsion were prepared and the effect of M-B on solid-state fermentation of Baijiu was investigated. The results showed that the release of M-B before and after drying was 53.27% and 25.77% in the liquid state (120 h) and 29.84% and 22.62% in the solid state (15 days), respectively. Adding M-B improved the alcohol by 0.33 %vol and reducing sugar content by 0.51%, reduced the residual starch content by 1.21% of the Jiupei, and had an insignificant effect on the moisture and acidity of the Jiupei. M-B have excellent sustained-release properties. The addition of M-B in solid-state fermentation significantly increased the alcohol content, reduced the residual starch content of Jiupei, ultimately improving the starch utilization rate and liquor yield of Baijiu brewing. The preparation of M-B provides methods and approaches for applying other active substances and microorganisms in the brewing of Baijiu. © 2023 Society of Chemical Industry.

Fungal Crude Lipase Enzyme Produced Using the SSF (Solid State Fermentation) Method Increases The Washing Test Performance

Lipase is an enzyme that commonly used in various industries, including the detergent industry to improve washing performance. Two fungal isolates (Al and Cl) has been reported to be highly active on high pH. This research aims to see the potential of those fungi (crude enzyme) in improving washing performance. Enzymes were produced using the SSF (Solid State Fermentation) method with sugarcane bagasse as a medium. To determine how adding enzymes might affect the effectiveness of washing, studies were conducted. The results show that washing performance increases from 52% (detergent only) to 74% in combination with the crude enzyme. It is concluded that Al has a potential to be involved in biodetergent production. Similar assays with concentrated enzymes are suggested for future studies.

Evaluation of fermented soybean meal by Bacillus subtilis as an alternative to fishmeal on the growth, and physiological status of Nile tilapia Oreochromis niloticus fingerlings

A feeding trial was conducted to investigate the effect of fermented soybean meal with Bacillus subtilis bacteria on growth performance, feed utilization, carcass composition, and hematological, and histological section of the liver and intestine of Nile tilapia Oreochromis niloticus fingerlings. Commercial soybean meal (SBM) containing 44% Crude Protein (CP) was fermented using the solid-state fermentation method which depended on autoclaving of SBM, then bacterial treatment injection by Bacillus subtilis, and finally incubation at 40C for 72 h then autoclaved to stop the growth of bacteria. Five isonitrogenous (25% crude protein) and isocaloric (4.4 kcal\\g gross energy) experimental fish meal-free diets were formulated to compare with a common control diet containing fishmeal and unfermented soybean meal. Diets without fish meal contain fermented soybean meal (FSM) as a sole protein, FSM with corn gluten (CG), FSM with free amino acid methionine (Meth), FSM with corn gluten and methionine, and unfermented soybean meal. Eighteen glass aquaria, 80-L net volume, were used to stock 10 fingerlings (10.0 ± 0.1 g/fish) in each aquarium in the replicates group. The feed amount was given three times daily, six days a week throughout the 98 days experimental period. Fish were weighed biweekly and feed amounts were adjusted based on the new fish weight. Bacterial fermentation enhanced the protein content of commercial soybean meals by 6%. The crude protein of fermented soybean meal increased from 43.44% to 50.67%. Used of FSM as a sole dietary protein source resulted in a decrease in growth rate and feed utilization. However, the incorporation of FSM with corn gluten, and/or methionine amino acid led to an improvement in the performance of fish. Finally, the best final body weight, weight gain, specific growth rate, protein efficiency ratio, and protein productive value were recorded by a fish-fed mixed plant protein diet (FSM + CG + Meth). Also, Hematocrit and red blood cells were not significantly affected including the FSM.

Fibrinolytic Protease Activity of Crude Enzyme from Fermented Sunflower (Helianthus annuus) and Common Bean (Phaseolus vulgaris) seeds by Rhizopus microsporus var. oligosporus FNCC 6010 in Solid State Fermentation

In the entire world, cardiovascular diseases (CVDs) are the main cause of death. For the treatment of CVDs, microbial fibrinolytic enzymes are highly regarded as novel therapeutic candidates. This study was purposed to determine the fibrinolytic protease activity produced by fungus source, which is Rhizopus microsporus var. oligosporus FNCC 6010 in fermented sunflower (Helianthus annuus) seed and common bean (Phaseolus vulgaris) seed. Fermentation was carried out by solid-state fermentation method at an initial pH of 5, incubation temperature of 33±1°C, and incubation time of 24 hours. The fermented seed was extracted to obtain supernatant as the crude enzyme. The proteolytic activity assay was done by the skimmed milk agar (SMA) plate method to obtain the proteolytic index, and the fibrinolytic activity assay was conducted by the fibrin-agarose plate method to get the fibrinolytic index. The results show that crude enzymes from fermented H. annuus and P. vulgaris seeds by R. microsporus have fibrinolytic protease activity with proteolytic index 2.64 ± 0.01 and 2.23 ± 0.04, respectively. The fibrinolytic index is 2.40 ± 0.06 and 1.64 ± 0.06, respectively. Therefore, the crude enzyme has the potential to be further researched as a candidate for thrombolytic agents. The purification, characterization, and in-depth research are needed to develop enzymes into preparations for preventing and treating CVDs.

Encapsulation of Pineapple Peel Extracts by Ionotropic Gelation Using Corn Starch, Weissella confusa Exopolysaccharide, and Sodium Alginate as Wall Materials.

Phenolic compounds that are present in pineapple by-products offer many health benefits to the consumer; however, they are unstable to many environmental factors. For this reason, encapsulation is ideal for preserving their beneficial effects. In this work, extracts were obtained by the combined method of solid-state fermentation with Rhizopus oryzae and ultrasound. After this process, the encapsulation process was performed by ionotropic gelation using corn starch, sodium alginate, and Weissella confusa exopolysaccharide as wall material. The encapsulates produced presented a moisture content between 7.10 and 10.45% (w.b), a solubility of 53.06 ± 0.54%, and a wettability of 31.46 ± 2.02 s. The total phenolic content (TPC), antioxidant capacity of DPPH, and ABTS of the encapsulates were also determined, finding 232.55 ± 2.07 mg GAE/g d.m for TPC, 45.64 ± 0.9 µm Trolox/mg GAE for DPPH, and 51.69 ± 1.08 µm Trolox/mg GAE for ABTS. Additionally, ultrahigh performance liquid chromatography (UHPLC) analysis allowed us to identify and quantify six bioactive compounds: rosmarinic acid, caffeic acid, p-coumaric acid, ferulic acid, gallic acid, and quercetin. According to the above, using ionotropic gelation, it was possible to obtain microencapsulates containing bioactive compounds from pineapple peel extracts, which may have applications in the development of functional foods.

Optimization of Esterase Production in Solid-State Fermentation of Agricultural Digestate

The continuous increase in biogas production poses the need for innovative applications for its by-products. Solid-state fermentation (SSF) has regained attention in the development of several products because of the possibility to use low-cost and easily available substrates, such as organic wastes. SSF represents a valuable process for agricultural digestate valorization in terms of enzyme production. In the present study, cellulase and esterase were produced by Trichoderma asperellum R on a digestate-based substrate in SSF, with esterase as the highest obtained activity. After assessing the effect of light on it, the esterase production in SSF was optimized using response surface methodology. The influence of substrate composition, temperature and humidity on the enzyme production was evaluated on two sets of data generated based on digestate concentration (50% and 70% w/w). The statistical analyses revealed that these parameters affected esterase production only when Trichoderma asperellum grew on substrate containing 50% w/w of digestate. The best esterase activity (264.6 mU/mg total protein) was achieved with the following optimized SSF parameters: 50% digestate, 50% fruits, 10% sawdust, 30 °C. The current finding of esterase production on digestate-based substrates makes the SSF method presented here a sustainable and completely circular technology.

Production, Optimization and Characterization of Amylase Using Solid State Fermentation Method

Amylases are enzymes produced by a wide range of organisms. The applications of these biomolecules cut across different industries such as detergent, brewing and food industries. <i>Aspergillus flavus</i> has been well documented as one the microbes capable of degrading starch-based agricultural waste materials. This study aimed at optimizing and characterizing amylase produced using agro-waste (potato peels) as a sole carbon source. <i>A. flavus</i> was obtained from the Department of Microbiology laboratory, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria. The fungus was preserved on PDA and stored at 4°C throughout the study period. This was followed by characterization and purification. Preliminary screening result showed that <i>A. flavus</i> had a clear zone of 13.33 mm (diameter of hydrolytic zone) and amylase activity of 545 U/ml. Stability assay revealed that the enzyme was stable at 50°C and 60°C by retaining 91% and 84% residual activities respectively after 4 h of pre-incubation period, while residual activities of 80% and 90% were observed at pH 6.0 and 8.0 respectively. Protein band analysis showed that the amylase from <I>A</I>. <i>flavus</i> had molecular weight of 35 kDa. These results indicated that the amylase produced from <i>A. flavus </i>had good catalytic properties and compared well with those from other known fungi. This study therefore recommends industrial production of amylase from <i>A. flavus</i> using potato peels as a substrate.

OPTIMIZATION OF ASPERGILLUS TUBINGENSIS GROWTH FOR CELLULASE PRODUCTION

Celluloses are the basic component of plant cell walls which are difficult to break however, cellulase enzymes have the ability to degrade the cellulose into glucose. The use of celullase enzymes is spreading widely particularly in the paper, pulp and food industries to reduce biowaste. The purpose of this study was to optimize the production of cellulase enzymes by using fungal strain Aspergillus tubingensis. The fungal strain Aspergillus tubingensis was extracted from putrid fruits and vegetable samples collected from the local fruit market of Pattoki in the District Kasur. The identification of fungus was carried out using microscope. Corn Stover was used as a substrate for cellulase production. Different parameters were used for the optimization of fungus growth such as substrate level, substrate particle size, temperature, pH, moisture, urea and glucose. Cellulase enzymes were purified by salting out and gel filtration techniques. The optimum substrate level, substrate particle size, temperature, pH, glucose, urea and moisture were analyzed as 5g, 40mm, 40°C, 4.5pH, 0.5g, 0.04g and 60% respectively. The maximum activity reveled by cellulase enzyme at different optimized parameters were reported in U/mL/min. The cellulase molecular weight was determined 71  kDa by Dodecyl Sulphate Poly Acrylamide Gel Electrophoresis. It was concluded that the study will help to a way for the scientists for the maximum production of cellulase from Aspergillus tubingensis using Corn stover as substrate and most cost-effective Solid State Fermentation method.

Valorization of Citrus Reticulata Peels for Flavonoids and Antioxidant Enhancement by Solid-State Fermentation Using Aspergillus niger CGMCC 3.6189

The bioactive components and bioactivities of citrus peel can be enhanced with microbial fermentation. Accordingly, this study investigated the ability of Aspergillus niger CGMCC3.6189 to accumulate flavonoids in Citrus reticulata peel powder (CRPP) by solid-state fermentation (SSF). Under the optimal SSF conditions including 80% moisture, 30 °C, pH 4.0, 4 × 107 spores/g d.w. CRPP, and 192 h, the total phenolic content (TPC), total flavonoid content (TFC), and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities of fermented CRPP significantly increased by 70.0, 26.8, 64.9, and 71.6%, respectively. HPLC analysis showed that after fermentation, the contents of hesperidin, nobiletin, and tangeretin were significantly increased from 19.36, 6.31, and 2.91 mg/g to 28.23, 7.78, and 3.49 mg/g, respectively, while the contents of ferulic acid and narirutin were decreased under the optimal fermentation conditions. Fermentation time is one of the most important factors that affect the accumulation of flavonoids and antioxidant activity; however, extended fermentation time increased the darkness of CRPP color. Therefore, our study provides a feasible and effective SSF method to increase the bioactive components and the antioxidant activity of CRPP that may be used in food, nutraceutical, and medicinal industries.

Effect of Rhizopus oryzae fermentation on proximate composition, anti-nutrient contents, and functional properties of banana peel flour

The present work aimed to evaluate the effect of fermentation by Rhizopus oryzae on the proximate composition, anti-nutrient contents, and functional properties of banana peel flour using the solid-state fermentation method in a tray bioreactor at 30°C for 96 h. Throughout fermentation, samples were obtained at different times (0/NF, 24, 48, 72, and 96 h), and analysed using standard procedures to determine the proximate composition, anti-nutrient contents, and functional properties. Based on the results, there were significant differences observed (p &lt; 0.05). Carbohydrate content decreased by 3.35%, while the crude protein, fat, ash, and crude fibre contents increased by 11.12, 2.43, 10.99, and 3.50%, respectively. Hydrogen cyanide, saponin, oxalate, and phytate contents decreased by 42.59, 25, 23.83, and 43.82%, respectively. Water absorption capacity (WAC) and the water solubility index (WSI) increased by 3.94 and 37.14%, respectively, while oil absorption capacity (OAC) decreased by 4.48%. These results showed that the fermentation of banana peel flour by R. oryzae has potential benefits for the food industry due to its effect on chemical composition and functional properties.

Production of Amylase by Aspergillus subflavus and Aspergillus fumigatus from flamevine flower (Pyrostegia venusta (Ker-Gawl.) Miers): A Tropical Plant in Bedugul Botanical Garden, Bali, Indonesia

Pyrostegia venusta is known as an ornamental plant with its source of antioxidants, cytotoxic, anti-inflammatory, and anti-HIV compounds. Ephypitic molds are potentially co-existed on the surface of this flower since it contains essential nutrients which support their growth. On the other hand, molds produce several enzymes that might involve flower growth. The presence of ephypitic molds on this flower provides information about its ability to produce amylase. This study successfully isolated molds from August flower (P. venusta) originating from Taman Nasional Bedugul, Bali, Indonesia. The study aimed to isolate potential amylase producer strains and optimize the enzyme production using Solid-State Fermentation (SSF) method. Ten mold isolates belonging to Universitas Negeri Jakarta Culture Collection (UNJCC) were selected according to their amylolytic index (IA) values, morphological identification, and colony count number. Selected strains were optimized for its growth to produce amylase using the SSF method under different temperatures (30, 40, 50°C) and pH (6, 7, 8) with a wheat brain fermentation medium. Results showed that UNJCC F100 (6.53 × 108 CFU/ml) and UNJCC F106 (9.83 x 108 CFU/ml) are the two isolates with the highest IA values of 1.34 ± 0.1 and 1.08 ± 0.12 among all isolates. Based on molecular identification using ITS region, UNJCC F100 and UNJCC F106 were identified as A. subflavus (97% homology) and A. fumigatus (99.52% homology), respectively. This study exhibited that both isolate UNJCC F100 and isolate UNJCC F106 have optimal amylase production conditions at 30°C and pH 6. The enzyme produced was 19.99 U/ml at 30°C and 34.33 U/ml at pH 6 for isolate UNJCC F100, and for isolate UNJCC F106 is 28.55±3.80 U/ml. The two isolates are potentially used for amylase production, referring to the specific environmental condition. However, to generate a higher amount with amylase activity, other external variables such as medium used, inoculum concentration, and fermentation method are important to consider further for a larger application.

English

The performance of twenty four 6-8 week old apparently healthy male and female weanling rabbits of mixed breed fed diets treated with aflatoxin, which contained 5% sweet orange (Citrus sinensis) fruit peel meal was evaluated in an 8 week feeding trial. Sweet orange peels were collected from orange sellers, sun-dried and milled. Fungal strain of Aspergillus flavus was cultured and inoculated into groundnut cake to produce aflatoxin using solid state fermentation method. Treated groundnut cake was incubated for seven days with incremental incubation temperature from 20-25 &ordm;C The groundnut cake was autoclaved, milled and, aflatoxin extracted from 10 g sample of the milled cake with 50 ml chloroform, and its concentration quantified by Thin Layer Chromatography (TLC). Treated groundnut cake was included at 0, 50, 100 and 150 gram in grower rabbit diets to produce diets T1, T2, T3 and T4, having 0 ppb, 50 ppb, 100 ppb and 150 ppb aflatoxin, respectively. The rabbits were randomly allocated to four diets at the rate of six per diet, housed singly in rabbit hutches, fed and served water free choice. The result showed significant (P&lt;0.05) negative effect&nbsp; of diets on final live weight, weight gain, feed intake, feed conversion ratio, water consumption, protein intake and protein efficiency ratio as the dietary aflatoxin increased from 0 ppb to 150 ppb. Also, diets had significant (P&lt;0.05) negative effect on dressed weight and carcass length and, kidney. Total aflatoxin residue varied significantly (P&lt;0.05) from 0 &mu;g/kg - 2.76&mu;g/kg,&nbsp; 0 &mu;g/kg - 1.94&mu;g/kg and 0 &mu;g/kg - 0.85&mu;g/kg for liver, kidney and meat tissue, respectively as the dietary aflatoxin increased from 0 ppb to 150 ppb. Performance response of rabbits was affected negatively by aflatoxin, thereby showing the inability of 5% dietary inclusion of sweet orange (Citrus sinensis) peel meal to mitigate the adverse consequences of aflatoxin intake by rabbit. Key words: Growth responses, residual level, visceral organs, mitigate.

Rhizopus oryzae AM16; a new hyperactive L-asparaginase producer: Semi solid-state production and anticancer activity of the partially purified protein.

The demand for L-asparaginase is predicted to increase several fold in the future due to its potential clinical applications in the treatment of lymphoid system malignancies and leukemia. Thus identifying suitable sources of production should be considered high priority. Fungi are valuable organisms as they are able to convert what would be considered ‘useless’ materials into materials that have potential value. The present study provides a proof of concept of production of a new hyperactive L-asparaginase producer (Rhizopus oryzae AM16), which was successfully isolated and sequentially optimized using a semi solid-state fermentation method with a simple and cheap medium produced from wheat bran (WB). The fungus was able to produce an appreciable amount of the enzyme (2,875.9 U) after 8 days of incubation under 85.7% moisture, in the presence of magnesium nitrate (5.0 mg N/mg nitrogen per gram of dry WB) at pH 5.8. Testing the anticancer activity confirmed the ability of the resultant enzyme to inhibit the growth of various types of cancer cells (HepG2, MCF-7, HCT and A549). The IC50 values of the dialyzed enzyme were lower than that of the crude product. Thus, this newly identified and purified L-asparaginase may be a promising anticancer drug.

Solid Fermentation of Bacillus thuringiensis: Method Development

Bacillus thuringiensis (Bt) is a significant bioinsecticidal agent that has been solely produced by liquid fermentation. With the increasing demand of bioinsecticides for organic agriculture, solid fermentation is preferred to enable low-cost and large-scale production of Bt. Therefore, in this study, we attempted to develop a solid state fermentation method to produce Bt by testing different solid substrates and also the effects of water percentage, fermentation time, temperature and seeding rate on the productions of biomass and parasporal crystal bodies (crystal proteins) of the Bt strain PAM33. Corn bran, rice bran and soybean meal are suitable to be utilized as substrates for biomass production. However, crystal proteins are only observed in solid fermentation using soybean meal as the substrate after 6 days of culture. The temperature range of 25-30°C and 10% seeding rate are the most suitable conditions for solid fermentation of strain PAM33 to obtain the bacterial density of approximate 109 CFU/g and the highest quantity of crystal proteins. This study shows that solid fermentation of Bt is feasible and effective to obtain bacterial biomass and crytal proteins by using cheap and available agricultural wastes. Thus, it can be a potential approach to produce the important Bt-based insecticide products for use in organic agriculture.

Antioxidant activities of solid‐state fermentation derived proteins and peptides from heat‐stabilized defatted rice bran

AbstractThe response surface methodology was used to optimize the effect of three parameters, Bacillus subtilis (natto) Takahashi inoculum log (5–7 log CFU/g HDRB), initial water content (25%–45% w/v), and fermentation time (24–72 h), as independent variables on the extraction of the maximum water‐soluble proteins and peptides (WSPP) from heat‐stabilized defatted rice bran (HDRB). The optimum conditions were achieved by fitting the second‐order polynomial equation. The result showed that all the factors, initial water content, inoculum log, and fermentation time, were critical in extracting WSPP from HDRB. The predicted optimum conditions for highest amount of WSPP extracted were 40.96% w/v water content, 6.27 log CFU/g HDRB inoculum log, and 61.01 h fermentation time. Under these optimized conditions of solid‐state fermentation (SSF), 64.6% ± 0.7% of total protein in HDRB was extracted as WSPP which was closer to the predicted value of 63.3%. While the WSPP extracted from nonfermented HDRB was 20.6%. The majority of the WSPP from SSF‐HDRB had MW &lt;5 kDa. The WSPP from SSF‐HDRB showed significant radical scavenging activities (56%, 44.4%, and 84.5%) in comparison to that from HDRB (12.5%, 9.3%, and 35.5%), of free radical (DPPH), superoxide radicals, and hydroxyl radicals, respectively. The SSF method is an efficient method to extract proteins and hydrolysates from HDRB and can find application as an ingredient in suitable products. Furthermore, the higher antioxidant activity is indicative of its potential function in controlling the oxidative stability in food products.

Anaerobic Solid-State Fermentation of Soybean Meal With Bacillus sp. to Improve Nutritional Quality.

The study evaluated the impact of fermentation with Bacillus sp. on the nutritional quality of soybean meal (SBM) and the changes of bacterial community structure during fermentation. High protease-producing strains were screened to degrade SBM macromolecular protein and anti-nutritional factors (ANFs). Unsterilized SBM then underwent an anaerobic solid-state fermentation method to evaluate the effects of fermentation. Results showed that for the nine high-producing protease strains that were screened, acid-soluble protein (ASP) contents in fermented SBM increased, with the highest value found to be 13.48%, which was fermented using strain N-11. N-11 was identified as Bacillus subtilis. N-11 fermentation reduced ANFs such as glycinin and β-conglycinin by 82.38 and 88.32%, respectively. During N-11 fermentation, the bacterial richness and diversity in SBM increased but not significantly. The high-yield protease strain B. subtilis N-11 selected in this experiment improved the nutritional quality of SBM through fermentation, and it can be used for industrial large-scale production.

Production and characterization of lipase from Penicillium aurantiogriseum under solid-state fermentation using sunflower pulp

Solid-State Fermentation (SSF) defined as a system in which the growth of microorganisms occurs on a moist solid substrate, shows tremendous potential in applications of microbial enzyme production as a low-cost, low-energy option. In this work, the production of lipase from Penicillium aurantiogriseum by using SSF was investigated. For this purpose, the sunflower pulp, an agro-industrial by-product, was utilized as a solid substrate in the SSF method. The optimization and characterization studies for lipase extract were performed by using the p-nitrophenyl palmitate (pNPP) (C16) as substrate. The lipase activity was found as 29.6 ± 0.11 U/mg protein at optimum conditions (50 mM of Tris-HCl buffer, pH 7.0, 40 °C). In thermal stability assay, the catalytic activities of lipase which are kept at 40, 50 and, 60 °C in a water bath for 1 h, were calculated as 100%, 60.48 ± 1.3%, 32.67 ± 0.2%, respectively. Also, the enzyme lost rapidly its activity within 15 min at 70 °C. The kinetic data, K m and V max , were determined as 0.17 mM and 2.9 µM/min, respectively. Also, 10 mM of Ba+2 ion had a slight activating effect (15%) showed on lipase. Lipase kept about 50% of its activity at 4 °C at the end of the 30 days. The hydrolytic activities of lipase for commercial olive oil and sunflower oil were found as 3.52 ± 0.1 U/mg and 3.90 ± 0.12 U/mg, respectively. The SSF method had obvious potential for the sustainable and cost-effective production of lipase from P. aurantiogriseum. Also, these results confirmed that the sunflower pulp could be used as an alternative substrate to produce enzymes in SSF conditions.