Next Article in Journal
Infections due to Rare Cryptococcus Species. A Literature Review
Next Article in Special Issue
Valorization of Lignocellulosic Wastes to Produce Phytase and Cellulolytic Enzymes from a Thermophilic Fungus, Thermoascus aurantiacus SL16W, under Semi-Solid State Fermentation
Previous Article in Journal
Isolation and Molecular Characterization of the Romaine Lettuce Phylloplane Mycobiome
Previous Article in Special Issue
Biocontrol Mechanisms of Trichoderma koningiopsis PSU3-2 against Postharvest Anthracnose of Chili Pepper
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

The Secretomes of Aspergillus japonicus and Aspergillus terreus Supplement the Rovabio® Enzyme Cocktail for the Degradation of Soybean Meal for Animal Feed

by
Delphine Grandmontagne
1,2,
David Navarro
1,3,
Virginie Neugnot-Roux
2,
Simon Ladevèze
1,4 and
Jean-Guy Berrin
1,*
1
INRAE, Aix Marseille University, BBF, UMR1163, 13009 Marseille, France
2
ADISSEO, 135 Avenue de Rangueil, INSA Toulouse, Hall Gilbert Durand, 31400 Toulouse, France
3
CIRM-CF (Centre International des Ressources Microbiennes- Champignons Filamenteux), INRAE, Aix Marseille University, 13009 Marseille, France
4
University of Cambridge, Sanger Building, 80 Tennis Ct Rd, Cambridge CB2 1GA, UK
*
Author to whom correspondence should be addressed.
J. Fungi 2021, 7(4), 278; https://doi.org/10.3390/jof7040278
Submission received: 3 March 2021 / Revised: 29 March 2021 / Accepted: 1 April 2021 / Published: 7 April 2021
(This article belongs to the Special Issue Exploiting Fungal Solutions for Today's Challenges)

Abstract

:
One of the challenges of the 21st century will be to feed more than 10 billion people by 2050. In animal feed, one of the promising approaches is to use agriculture by-products such as soybean meal as it represents a rich source of proteins. However, soybean meal proteins are embedded in a complex plant cell wall matrix, mostly composed of pectic polysaccharides, which are recalcitrant to digestion for animals and can cause digestive disorders in poultry breeding. In this study, we explored fungal diversity to find enzymes acting on soybean meal components. An exploration of almost 50 fungal strains enabled the identification of two strains (Aspergillus terreus and Aspergillus japonicus), which improved the solubilization of soybean meal in terms of polysaccharides and proteins. The two Aspergilli strains identified in the frame of this study offer a promising solution to process industrial food coproducts into suitable animal feed solutions.

1. Introduction

Since the middle of the 20th century, the human population has tripled, reaching 7 billion today and most probably 10 billion by 2050 [1,2,3]. In order to maintain access to nutrition, a sustainable production of cereals and meat is essential. Feeding animals represents about 60–70% of the price in poultry production system. In the current context of the development of a circular economy, a promising approach is to feed animals with agriculture by-products such as rapeseed, canola, sunflower, and soybean meal (SBM) [4]. These bioresources are complex: mostly composed of polysaccharides and proteins embedded in a plant cell wall matrix. The rich amino acid value of SBM makes it very attractive for poultry and swine industries [5]. SBM is composed of 44–50% crude proteins, 3% crude fat, and about 35% carbohydrates [6]. Cell wall carbohydrates contain 10% of free sugars (sucrose, stachyose, and raffinose), 8% of cellulose, and 17% of pectins (mainly rhamnogalacturonan I (RGI), arabinogalactan, and xylogalacturonan polymers) [7]. Even though carbohydrates are the most important energy sources for nonruminant and ruminant animals [8], SBM is not digestible by poultry since their digestive tracts do not display the endogenous enzymes required to degrade these polysaccharides [9]. Like most of the agricultural by-products used in animal feed, SBM need to be bioprocessed to become digestible [10], as it can lead to digestive disorder, gas accumulation, diarrhea, and lack of nutrients [11], thus decreasing the yield of meat production.
Addition of exogenous enzymes in animal diets can increase the production of meat per animal, thereby decreasing the time and cost of production [12]. Since the 1980s, exogenous enzymes (cellulases, phytases, xylanases, pectinases, and proteases) have been commonly used to supplement endogenous enzymes secreted by the digestive tract of the animal [9,13,14,15,16]. Most of the exogenous enzymes used in animal feed are of fungal origin. Indeed, the use of fungi in the degradation of plant raw material is well recognized as they secrete a rich panel of enzymes (i.e., secretome) able to degrade complex biomass [17,18,19,20,21,22]. Fungi can adapt their secretomes depending on environmental conditions, including the growth substrate, temperature, and growth phases [20,23]. These fungal secretomes have allowed the development of industrial enzymatic cocktails, including in the animal feed field. The Rovabio® is an enzymatic cocktail produced from the ascomycete fungus Talaromyces versatilis [24]. The Rovabio® cocktail contains more than 200 different enzymes, mostly carbohydrate-active enzymes (CAZymes; [25]), which target the different components of plant cell wall, cellulose, and hemicelluloses [26]. This cocktail, which is efficient for enhancing broiler feed digestibility [27,28,29,30,31], was improved using GH62 arabinofuranosidases [27,32] and GH10 and GH11 xylanases [33,34] to increase its ability to degrade recalcitrant nonstarch polysaccharides (i.e., xylans). However, for pectin-rich biomasses, especially SBM, there is a possibility to improve established enzymatic cocktails.
In this study, fungal diversity was explored, without a priori knowledge, as a source of enzymes for SBM degradation. Exploration of fungal diversity is a relevant approach to find enzymes of interest for many biotechnological applications [17,35,36]. Herein, the potential of fungal strains to grow on SBM was evaluated to select a few strains of interest. Several fungal secretomes were produced, and their efficiency was assessed using a simple method to easily measure SBM solubilization as well as proteins and sugars solubilization.

2. Material and Methods

2.1. Fungal Strains

Fungal strains were from the CIRM-CF (Centre International de Ressources Microbiennes-Champignons Filamenteux, INRAE, Marseille, France) collection. All strains were authenticated using classical taxonomy, enzymatic characterization, and ITS (internal transcribed spacer) molecular tools [37] as previously described [17].
Forty-nine fungal strains were selected from the CIRM-CF collection. They represent a wide diversity with 33 different families belonging to the basidiomycetes (29 strains), ascomycetes (16 strains), and mucuromycetes (four strains) (Table 1). Although all these fungi are not known to be animal pathogens, we carefully checked the literature to avoid any known production of antibiotics or mycotoxins that could represent a potential risk for the health of animals.
Each fungal strain was incubated on different solid media: a minimum control medium containing only agar and a rich control medium (containing potato dextrose agar for ascomycetes and mucoromycetes strains, and malt-agar medium (malt extract, 2% w/v) for basidiomycetes). Two other media with 15 g/L SBM (based on dry matter) were produced. The first one contained agar and micronized raw SBM, and the second one contained agar and recalcitrant micronized SBM. Recalcitrant micronized SBM was prepared by hydrolysis of SBM with the Rovabio® enzymatic cocktail. For this, 120 g of rough SBM were hydrolyzed by 8 mL of Rovabio® (90 mg of protein per mL) for 24 h, at 37 °C, 130 rpm in sodium acetate buffer (100 mM, pH 4). After hydrolysis, recalcitrant SBM was washed with water twice and finally dried for 48 h at 60 °C. Then, the SBM was ball-milled to obtain 40 g of micronized SBM powder (below 100 µm particle size). Fungi were incubated at 25 °C. At 5, 8, and 11 days of growth, diameter and growth density were measured. The density of the mycelium was evaluated using scores ranging from 1 to 5, by comparison of mycelium densities to the control media (score of 1 when equivalent to poor control media and score of 5 when equivalent to rich control media).

2.2. Culture Conditions and Secretome Preparation

Fungal secretomes were prepared based on previous observations [38]. Selected fungal strains were cultured on rich agar media for 10 days to produce their secretomes. The spores of the sporulating fungi were used directly to inoculate the culture media (2 × 105 spores/mL). Basidiomycetes need an extra Roux’s flask step. The Roux’s flask medium was composed of yeast extract (20 g/L), bactopeptone (40 g/L), and glucose (100 g/L). When the fungal mycelium covered the surface of Roux’s flask (between 10 and 50 days depending on the strains), fungi were filtered and mixed to inoculate the media (between 400 and 600 mg of fungal biomass per liter of media). Fungal cultures were grown in 500 mL baffled flasks, in a 100 mL liquid medium containing 15 g/L (based on the dry matter) of autoclaved biomass (cellulose, micronized sugar beet pulp (SBP) or micronized SBM) as a carbon source, 2.5 g/L of maltose as a starter, 1.842 g/L of diammonium tartrate as a nitrogen source, 0.5 g/L yeast extract, and salts (KH2PO4: 0.2 g/L; CaCl2: 0.0132 g/L; MgSO4: 0.5 g/L). Flasks were incubated at 30 °C, with orbital shaking at 120 rpm. After 7 days of inoculation, the culture broths (secretomes) were harvested and pooled (total volume 300 mL per condition). Supernatants were filtered through a 10-kDa pore-sized membrane (Vivaspin polyethersulfone, Sartorius, Göttingen, Germany), diafiltered in sodium acetate buffer (50 mM, pH 5), and concentrated to a final volume of 10 mL. Secretomes were finally aliquoted and stored at −20 °C for further use. The protein content of each secretome was analyzed using a 10% Tris-glycine precast SDS-PAGE stain-free gel (Bio-rad, Marnes-la-Coquette, France) stained using Coomassie blue. The molecular mass under denaturing conditions was determined with PageRuler prestained protein ladder (Thermo Fisher Scientific, Bartlett, IL, USA).

2.3. Liquid Fermentation in Bioreactor Conditions

Aspergillus terreus cultures were performed in 2 liter bioreactors, containing a 1.5 liter liquid medium based on 15 g/L (based on the dry matter) of autoclaved biomass (micronized or 3 mm particles sized SBP) as a carbon source, 2.5 g/L of maltose as a starter, 1.842 g/L of diammonium tartrate as a nitrogen source, 0.5 g/L yeast extract, salts (KH2PO4: 0.2 g/L; CaCl2: 0.0132 g/L; MgSO4: 0.5 g/L), 0.05 g/L Tween 80, and anti-foam. Bioreactors were incubated at 30 °C, with 8 L/h O2 and orbital shaking at 120 rpm (marine propellers). After 7/10 days of inoculation, secretomes were harvested. Supernatants were then filtered on a 10-kDa pore-sized membrane (Vivaspin polyethersulfone, Sartorius) and filtered dialyzed in sodium acetate buffer (pH 5, 50 mM) and concentrated to a final volume of 10 mL. They were aliquoted and stored at −20 °C for further use.

2.4. Enzymatic Degradation of Soybean Meal

Micronized SBM (150 mg) was treated with the secretomes (0.1 mg of proteins) of selected fungi in 2 mL Eppendorf tubes. Secretomes were diluted in 1 mL sodium acetate buffer (100 mM, pH 4). The samples were incubated on an orbital shaker at 850 rpm for 24 h at 37 °C. Reactions were stopped by addition of 1 mL of KOH 0.34% (w/v) and incubated for 20 min on a digital tube revolver (ThermoFisher scientific, Waltham, MA, USA) at 20 rpm. Samples were then centrifuged at 4 °C, 11,000 g for 15 min, and supernatants were collected to perform DNS, TNBS, and Bradford assays (see below). The pellets were washed three times with water and dried at 100 °C to perform dry matter measurements and deduce SBM solubilization.
The reducing sugars released were quantified using the dinitrosalicylic acid (DNS) assay [39], proteins released (Araba and Dale, 1990) were quantified using the Bradford assay [40] and the TNBS (2, 4, 6-Trinitrobenzenesulfonic acid) assay [41], respectively.
The commercial enzymes used were Rovabio® Advance (Adisseo, Toulouse, France) and a preparation serine-protease (DSM, Village-Neuf, France).

2.5. Sugar Composition

To evaluate the monomeric sugar composition of polysaccharides, pellets were hydrolyzed with sulfuric acid (76% (v/v), 30 min, 30 °C). Another sulfuric acid hydrolysis was performed (1 M, 100 °C, 2 h). Neutral sugars derivatization was performed with alditol acetate and analyzed on gas-phase chromatography [42]. Acidic sugars were evaluated with the Skalar system, using the colorimetric MHDP method [43].

3. Results and Discussion

3.1. Exploration of Fungal Biodiversity

The ability of filamentous fungi to degrade lignocellulosic biomass has been studied in a range of basidiomycetes and ascomycetes [17,20,38] but to our knowledge, no large screening has been performed using SBM as substrate. Here, four media were used to test the ability of fungi isolates to grow on SBM. Among these four media, two were used as controls to confirm the capacity of each fungal strain to grow on the MA2 or PDA media (rich media) while not being able to do so on the agar media (poor medium). The two other media contained micronized SBM and were prepared to test the ability of each fungal strain to grow on SBM. To get a more selective substrate, we prepared a “recalcitrant SBM” by hydrolyzing it using the Rovabio® enzyme cocktail.
Out of the 49 isolates, 44 strains were able to grow on SBM and recalcitrant SBM substrates with a growth diameter larger than 2 cm. The selection was done after 8 days of growth, as it was the midterm growth for most of fungi under our experimental conditions (Supplementary Materials Table S1). To measure fungal growth, two parameters were used: the growth diameter and density of the mycelium (Figure 1). Growth diameters were measured in centimeters. As fungi are able to produce filaments to explore their environment without degrading the substrate, the thickness of these filaments was evaluated by comparison to the controls (poor and rich medium control plates) and described as “density” of the growth.

3.2. Selection of the Fungal Strains

None of the 49 strains tested grew on the agar medium, while a thick and abundant mycelium was observed in the rich medium condition. The selection criteria were a diameter wider than 4 cm and a density above 3 (corresponding to an intermediate filamentous density between the filamentous density obtained on both the poor medium and the rich media) on SBM or/and recalcitrant SBM media (Supplementary Materials Table S1). Using these criteria, we selected 14 strains, among which 7 were basidiomycetes: Dichostereum effuscatum (BRFM 91); Lentinula edodes (BRFM 353); Oxysporus latemarginatus (BRFM 678); Pleurotus ostreatus (BRFM 853); Pycnoporus sanguineus (BRFM 902); Gymnopilus junonius (BRFM 969); Amauroderma calcigenum (BRFM 1190); two mucoromycetes: Rhizopus arrhizus var. arrhizus (BRFM 1095); Absidia glauca (BRFM 2463); and five ascomycetes: Nectria pseudotrichia (BRFM 1017); Neurospora crassa (BRFM 1092); Pestalotiopsis sp. (BRFM 1648); Aspergillus japonicus (BRFM 405); and Aspergillus terreus (BRFM 111).

3.3. Fungal Secretomes Production

The next step was to investigate the enzymes secreted by these fungal strains upon growth on SBM. We decided to further characterize only the strains for which genomic data were available to facilitate future postgenomic analyses. Therefore, we restricted our study to five strains: A. glauca (BRFM 2463), G. junonius (BRFM 969), A. japonicus (BRFM 405), A. terreus (BRFM 111), and L. edodes (BRFM 353).
Fungal enzymes secretion is regulated by the type and the complexity of the substrate used as inducer in the culture [20,38,39]. In this study, we selected three different types of plant biomass: cellulose, SBP, and SBM as they differ in terms of composition. While cellulose is widely used as an inducer to favor the secretion of fungal CAZymes, SBP is rich in pectin, and SBM is our biomass of interest. All the fungal isolates tested were able to grow on these three substrates with a satisfactory yield of protein secretion (Table S1). After 7 days of growth, fungal cultures were harvested and secretomes were filtered, dialyzed, and analyzed using SDS-PAGE, revealing a diversity of secreted protein profiles (Figure S1).

3.4. Development of a Simple Method to Assess the Efficiency of Each Secretome to Degrade Soybean Meal

The objective was to develop a simple method to allow parallelization of fungal secretomes analyses (Figure 2). The Rovabio® enzyme cocktail containing CAZymes and serine proteases were used to develop the method. The reaction volume was set at 2 mL and the SBM quantity to 150 mg per assay using SBM micronized to a diameter below 100 µm (Figure 2). At this scale, we were able to confidently evaluate SBM degradation (Figure 2). Indeed, the low standard deviations could be considered a global measure of the reproducibility of each step of the method (substrate micronization, distribution, and incubation). This new method enabled to envisage the evaluation of fungal secretomes potential alone or in combination with the Rovabio® cocktail.

3.5. Hydrolysis of Soybean Meal with Fungal Secretomes

The ability of each secretome to hydrolyze SBM was first evaluated by measuring the residual dry matter before and after the action of each fungal secretome (Figure 3).
Although all the fungal strains were able to grow on SBM plates, only the secretomes of Absidia glauca, Aspergillus terreus and Aspergillus japonicus grown on SBM and SBP (and to a lesser extent Lentinula edodes) were able to significantly solubilize the SBM. As the objective of this study was to upgrade the Rovabio® cocktail, we first assessed the amount of Rovabio® enzymes to use in our assays. We established a relationship between the SBM solubilization and the amount of enzymes added for hydrolysis. In order to test whether the secretomes are able to supplement Rovabio®, the dose of Rovabio® should not be chosen as a stopgap to the degradation of the meal. For this reason, a dose of 0.9 mg of enzyme was selected for the rest of the study (Figure S2). The supplementation of the Rovabio® enzymatic cocktail was then performed with the nine secretomes produced (Figure 4). Out of the nine secretomes tested, significant improvements were observed with the A. terreus and A. japonicus secretomes. The most important improvement was obtained with the secretome of A. terreus and led to a significant increase of 28 mg of SBM solubilization. Overall, SBM inducer was not as efficient as SBP to produce a secretome able to supplement Rovabio® enzymatic cocktail. The choice of the inductor is therefore crucial for the production of functional secretomes.
As both A. terreus and A. japonicus were able to supplement Rovabio®, we investigated the ability of other strains from the genus Aspergillus to supplement Rovabio®. We performed the same SBM hydrolysis assays with A. niger (BRFM 280), A. brasiliensis (BRFM 103), A. tubenginsis (BRFM 1521), A. japonicus (BRFM 405), and A. terreus (BRFM 111). We observed that all the Aspergilli strains are not able to supplement the Rovabio® (Figure S3).

3.6. Effect of the Aspergilli Secretomes on the Release of Proteins and Sugars from Soybean Meal

To better understand the effect of A. japonicus (BRFM 405) and A. terreus (BRFM 111) secretomes on SBM, several complementary methods were used. The measurements of soluble sugars and proteins released were performed using the DNS and Bradford assays, respectively (Figure 5). A measurement of protein cleavage was also preformed using the TNBS method to evaluate proteolytic digestion (Figure 5). Following the addition of increasing amounts of enzymes from each secretome, the SBM solubilization gradually increased (Figure 5A). The boosting effect was the most significant with the secretome of A. terreus (1.8 mg), leading to 39% of solubilized matter compared to 17% when Rovabio® was used alone. Supplementation of Rovabio® with the different Aspergilli secretomes improved the solubilization of proteins. The TNBS assay revealed that the A. terreus secretome cleaves soybean proteins into smaller peptides compared to the A. japonicus secretome (Figure 5B). The supplementation of Rovabio® with the different Aspergilli secretomes also increased the release of soluble sugars (Figure 5C). Although the DNS method can evaluate the reducing ends, it does not give any information about the length of the released sugars. Even though the increase observed in soluble sugars released suggests that the number of cleavages in soybean polysaccharides is higher in supplemented conditions, it does not give any information about the nature of the sugars.
Therefore, we performed a compositional analysis of the sugar monomers (rhamnose, fucose, arabinose, xylose, mannose, galactose, glucose, and uronic acids) present in the residual fraction of the SBM after enzymatic hydrolysis by Rovabio® supplemented or not by A. japonicus or A. terreus (Table 2). The most striking effect was observed using the secretome of A. terreus, which significantly decreased the amount of fucose, arabinose, xylose, galactose, glucose, and uronic acids compared to the Rovabio® alone.
Based on the analysis of the sugar composition, we believe the observed boosting effect to be due to the solubilization of pectins. Soybean pectic polysaccharides are mainly composed by RGI [44,45,46,47], a complex polysaccharide composed of a backbone of alternating rhamnose and galacturonic acid residues with side chains containing galactose and/or arabinose residues. The structure of these side chains and the degree of substitution of rhamnose residues are extremely variable. Its complete hydrolysis requires the complementary action of more than 30 CAZymes [48]. Previous studies have shown that the Rovabio® enzymatic cocktail displays a limited number of CAZymes acting on pectin, with only GH28 polygalacturonases, GH78 rhamnosidases, and GH53 endo-galactanases [24,26,27]. This suggests that the Aspergilli secretomes may contain specific CAZymes targetting pectin that are absent in the Rovabio® cocktail. Aspergilli are well known for their ability to secrete pectinolytic enzymes [49,50,51,52]. For instance, Aspergillus niger has been studied under 16 different growth conditions to determine the role of the 26 genes encoding secreted pectinolytic enzymes [53]. It is therefore not surprising to find some Aspergilli strains with high potential for the degradation of SBM when supplemented with the Rovabio® enzyme cocktail. However, this ability to degrade SBM does not apply to all Aspergilli strains tested in the frame of this study; as we demonstrated, A. niger (BRFM 280) and A. brasiliensis (BFRM 103) were not efficient to supplement the Rovabio® (Figure S3).

3.7. Upscaling the Production of A. terreus Secretome in Bioreactor

To upscale and validate the supplementation effect of the A. terreus secretome, a bioreactor production was carried out. Three different 2-L bioreactors were prepared with variations in the number of spores inoculated and the size of the SBP particles (Table S2). The secretomes produced were collected and tested for their ability to supplement the Rovabio® cocktail as previously described. All secretomes of A. terreus produced in bioreactor were able to improve SBM solubilization to the same extend as Rovabio® supplemented by A. terreus produced in flask (Figure 6A). Of note, the supplementation using A. terreus secretomes produced in bioreactor F3 released more proteins (Figure 6B) than the secretomes produced in flask. Supplementation of Rovabio® with all the different A. terreus secretomes produced in bioreactors released more sugars than the secretomes produced in flasks (Figure 6C). The fact that we managed to keep the boosting effect on SBM using Aspergilli secretomes produced in bioreactor is promising for further investigations at higher scale to attempt in vivo assays which require higher amount of enzymes [13,54].

4. Conclusions

In this study, we demonstrated the high potential of two Aspergilli strains, A. japonicus (BRFM 405) and A. terreus (BRFM 111), to upgrade the enzymatic cocktail Rovabio® for SBM degradation. These fungal secretomes and their enzymes offer a promising solution to process industrial food coproducts into suitable animal feed solutions in the current context of circular economy. This study paves the way for future work aimed at identifying and characterizing the enzymes responsible for this improvement.

Supplementary Materials

The following are available online at https://www.mdpi.com/article/10.3390/jof7040278/s1, Figure S1: Electrophoresis profiles of each secretomes used for Rovabio® enzymatic cocktail supplementation. Figure S2: Solubilization of soybean meal using different amounts of Rovabio®. Figure S3: Enzymatic degradation of soybean meal by different strains of Aspergilli. Table S1: Protein content of each produced and concentrated secretomes for Rovabio® enzymatic cocktail supplementation. Table S2: Presentation of different tested parameters in bioreactor experiments.

Author Contributions

Conceptualization, J.-G.B. and V.N.-R.; Methodology, D.G., D.N., and S.L.; Data curation, all authors; Writing—original draft preparation, D.G. and J.-G.B.; Writing—review and editing, all authors; Supervision, J.-G.B. and V.N.-R.; Funding acquisition, J.-G.B. and V.N.-R. All authors have read and agreed to the published version of the manuscript.

Funding

The Adisseo company and the “Association Nationale Recherche Technologie” (ANRT) are acknowledged for funding the Ph.D. fellowship of D.G. (grant no. 2017/1206).

Data Availability Statement

The data presented in this study are available in article and Supplementary Materials.

Acknowledgments

The authors thank Sophie Le Gall (BIBS platform, INRAE Angers-Nantes, France) for her help in dry matter sugar composition.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Calinoiu, L.F.; Mitrea, L.; Precup, G.; Bindea, M.; Rusu, B.; Szabo, K.; Dulf, F.V.; Stefanescu, B.E.; Vodnar, D.C. Sustainable Use of Agro-Industrial Wastes for Feeding 10 Billion People by 2050. In Professionals in Food Chains; Wageningen Academic Publishers: Wageningen, The Netherlands, 2018; pp. 482–486. [Google Scholar]
  2. Hickey, L.T.; Hafeez, A.N.; Robinson, H.; Jackson, S.A.; Leal-Bertioli, S.C.M.; Tester, M.; Gao, C.; Godwin, I.D.; Hayes, B.J.; Wulff, B.B.H. Breeding Crops to Feed 10 Billion. Nat. Biotechnol. 2019, 37, 744–754. [Google Scholar] [CrossRef] [Green Version]
  3. Lal, R. Feeding 11 Billion on 0.5 Billion Hectare of Area under Cereal Crops. Food Energy Secur. 2016, 5, 239–251. [Google Scholar] [CrossRef] [Green Version]
  4. Pickard, M.D.; da Lima, R.S.S.; Shahidi, F. By-Product Utilization. In Bailey’s Industrial Oil and Fat Products; American Cancer Society: Atlanta, GA, USA, 2020; pp. 1–27. [Google Scholar]
  5. Feng, J.; Liu, X.; Xu, Z.R.; Lu, Y.P.; Liu, Y.Y. Effect of Fermented Soybean Meal on Intestinal Morphology and Digestive Enzyme Activities in Weaned Piglets. Dig. Dis. Sci. 2007, 52, 1845–1851. [Google Scholar] [CrossRef]
  6. Karr-Lilienthal, L.K.; Kadzere, C.T.; Grieshop, C.M.; Fahey, G.C. Chemical and Nutritional Properties of Soybean Carbohydrates as Related to Nonruminants: A Review. Livest. Prod. Sci. 2005, 97, 1–12. [Google Scholar] [CrossRef]
  7. Choct, M.; Dersjant-Li, Y.; McLeish, J.; Peisker, M. Soy Oligosaccharides and Soluble Non-Starch Polysaccharides: A Review of Digestion, Nutritive and Anti-Nutritive Effects in Pigs and Poultry. Asian-Australas J. Anim. Sci. 2010, 23, 1386–1398. [Google Scholar] [CrossRef]
  8. Knudsen, K.E.B. Carbohydrate and Lignin Contents of Plant Materials Used in Animal Feeding. Anim. Feed Sci. Technol. 1997, 67, 319–338. [Google Scholar] [CrossRef]
  9. Ao, T. Using Exogenous Enzymes to Increase the Nutritional Value of Soybean Meal in Poultry Diet. In Soybean and Nutrition; IntechOpen: London, UK, 2011; pp. 201–214. [Google Scholar]
  10. Ajila, C.; Brar, K.; Verma, M.; Tyagi, R.; Godbout, S.; Valéro, J. Bio-Processing of Agro-Byproducts to Animal Feed. Crit. Rev. Biotechnol. 2012, 32, 382–400. [Google Scholar] [CrossRef] [PubMed]
  11. Smith, R.A. Impact of Disease on Feedlot Performance: A Review. J. Anim. Sci. 1998, 76, 272–274. [Google Scholar] [CrossRef]
  12. Imran, M.; Nazar, M.; Saif, M.; Khan, M.A.; Sanaullah, D.; Vardan, M.; Javed, O. Role of Enzymes in Animal Nutrition: A Review. PSM Vet. Res. 2016, 1, 38–45. [Google Scholar]
  13. Marsman, G.J.; Gruppen, H.; van der Poel, A.F.; Kwakkel, R.P.; Verstegen, M.W.; Voragen, A.G. The Effect of Thermal Processing and Enzyme Treatments of Soybean Meal on Growth Performance, Ileal Nutrient Digestibilities, and Chyme Characteristics in Broiler Chicks. Poult. Sci. 1997, 76, 864–872. [Google Scholar] [CrossRef] [PubMed]
  14. Malathi, V.; Devegowda, G. In Vitro Evaluation of Nonstarch Polysaccharide Digestibility of Feed Ingredients by Enzymes. Poult. Sci. 2001, 80, 302–305. [Google Scholar] [CrossRef]
  15. Ogunkoya, A.E.; Page, G.I.; Adewolu, M.A.; Bureau, D.P. Dietary Incorporation of Soybean Meal and Exogenous Enzyme Cocktail Can Affect Physical Characteristics of Faecal Material Egested by Rainbow Trout (Oncorhynchus Mykiss). Aquaculture 2006, 254, 466–475. [Google Scholar] [CrossRef]
  16. Li, Q.; Ray, C.S.; Callow, N.V.; Loman, A.A.; Islam, S.M.M.; Ju, L.-K. Aspergillus Niger Production of Pectinase and α-Galactosidase for Enzymatic Soy Processing. Enzyme Microb. Technol. 2020, 134, 109476. [Google Scholar] [CrossRef] [PubMed]
  17. Berrin, J.-G.; Navarro, D.; Couturier, M.; Olivé, C.; Grisel, S.; Haon, M.; Taussac, S.; Lechat, C.; Courtecuisse, R.; Favel, A.; et al. Exploring the Natural Fungal Biodiversity of Tropical and Temperate Forests toward Improvement of Biomass Conversion. Appl. Environ. Microbiol. 2012, 78, 6483–6490. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  18. Bouws, H.; Wattenberg, A.; Zorn, H. Fungal Secretomes—Nature’s Toolbox for White Biotechnology. Appl. Microbiol. Biotechnol. 2008, 80, 381–388. [Google Scholar] [CrossRef] [PubMed]
  19. Chettri, D.; Verma, A.K.; Verma, A.K. Innovations in CAZyme Gene Diversity and Its Modification for Biorefinery Applications. Biotechnol. Rep. 2020, 28, e00525. [Google Scholar] [CrossRef] [PubMed]
  20. Couturier, M.; Navarro, D.; Olivé, C.; Chevret, D.; Haon, M.; Favel, A.; Lesage-Meessen, L.; Henrissat, B.; Coutinho, P.M.; Berrin, J.-G. Post-Genomic Analyses of Fungal Lignocellulosic Biomass Degradation Reveal the Unexpected Potential of the Plant Pathogen Ustilago maydis. BMC Genom. 2012, 13, 1–14. [Google Scholar] [CrossRef] [Green Version]
  21. Rotter, B.; Friesen, O.D.; Guenter, W.; Marquardt, R. Influence of Enzyme Supplementation on the Bioavailable Energy of Barley. Poult. Sci. 1990, 69, 1174–1181. [Google Scholar] [CrossRef]
  22. Zhao, Z.; Liu, H.; Wang, C.; Xu, J.-R. Comparative Analysis of Fungal Genomes Reveals Different Plant Cell Wall Degrading Capacity in Fungi. BMC Genom. 2013, 14, 274–288. [Google Scholar] [CrossRef] [Green Version]
  23. Alfaro, M.; Oguiza, J.A.; Ramírez, L.; Pisabarro, A.G. Comparative Analysis of Secretomes in Basidiomycete Fungi. J. Proteom. 2014, 102, 28–43. [Google Scholar] [CrossRef]
  24. Llanos, A.; Déjean, S.; Neugnot-Roux, V.; François, J.M.; Parrou, J.-L. Carbon Sources and XlnR-Dependent Transcriptional Landscape of CAZymes in the Industrial Fungus Talaromyces Versatilis: When Exception Seems to Be the Rule. Microb. Cell Fact. 2019, 18, 14–39. [Google Scholar] [CrossRef]
  25. Lombard, V.; Golaconda Ramulu, H.; Drula, E.; Coutinho, P.M.; Henrissat, B. The Carbohydrate-Active Enzymes Database (CAZy) in 2013. Nucleic Acids Res. 2014, 42, D490–D495. [Google Scholar] [CrossRef] [Green Version]
  26. Guais, O.; Borderies, G.; Pichereaux, C.; Maestracci, M.; Neugnot, V.; Rossignol, M.; François, J.M. Proteomics Analysis of “RovabioTM Excel”, a Secreted Protein Cocktail from the Filamentous Fungus Penicillium Funiculosum Grown under Industrial Process Fermentation. J. Ind. Microbiol. Biotechnol. 2008, 35, 1659–1668. [Google Scholar] [CrossRef] [PubMed]
  27. Cozannet, P.; Kidd, M.T.; Montanhini Neto, R.; Geraert, P.-A. Next-Generation Non-Starch Polysaccharide-Degrading, Multi-Carbohydrase Complex Rich in Xylanase and Arabinofuranosidase to Enhance Broiler Feed Digestibility. Poult. Sci. 2017, 96, 2743–2750. [Google Scholar] [CrossRef] [PubMed]
  28. Lee, S.-Y.; Kim, J.-S.; Kim, J.-M.; An, B.-K.; Kang, C.W. Effects of Multiple Enzyme (ROVABIO® Max) Containing Carbohydrolases and Phytase on Growth Performance and Intestinal Viscosity in Broiler Chicks Fed Corn-Wheat-Soybean Meal Based Diets. Asian-Australas. J. Anim. Sci. 2010, 23, 1198–1204. [Google Scholar] [CrossRef]
  29. Rios, H.V.; Vieira, S.; Stefanello, C.; Kindlein, L.; Soster, P.; Dos Santos, P.I.; Toscan, A.B. Energy and Nutrient Utilisation of Maize-Soy Diet Supplemented with a Xylanase-β-Glucanase Complex from Talaromyces Versatilis. Anim. Feed Sci. Technol. 2017, 232, 80–90. [Google Scholar] [CrossRef]
  30. Saleh, A.A.; Kirrella, A.A.; Abdo, S.E.; Mousa, M.M.; Badwi, N.A.; Ebeid, T.A.; Nada, A.L.; Mohamed, M.A. Effects of Dietary Xylanase and Arabinofuranosidase Combination on the Growth Performance, Lipid Peroxidation, Blood Constituents, and Immune Response of Broilers Fed Low-Energy Diets. Animals 2019, 9, 467. [Google Scholar] [CrossRef] [Green Version]
  31. Cozannet, P.; Kidd, M.T.; Yacoubi, N.; Geraert, P.A.; Preynat, A. Dietary Energy and Amino Acid Enhancement from a Multi-enzyme Preparation. J. Appl. Poult. Res. 2019, 28, 136–144. [Google Scholar] [CrossRef]
  32. De La Mare, M.; Guais, O.; Bonnin, E.; Weber, J.; Francois, J.M. Molecular and Biochemical Characterization of Three GH62 α-l-Arabinofuranosidases from the Soil Deuteromycete Penicillium funiculosum. Enzyme Microb. Technol. 2013, 53, 351–358. [Google Scholar] [CrossRef] [PubMed]
  33. Lafond, M.; Bouza, B.; Eyrichine, S.; Bonnin, E.; Crost, E.H.; Geraert, P.-A.; Giardina, T.; Ajandouz, E.H. An Integrative in Vitro Approach to Analyse Digestion of Wheat Polysaccharides and the Effect of Enzyme Supplementation. Br. J. Nutr. 2011, 106, 264–273. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  34. Lafond, M.; Bouza, B.; Eyrichine, S.; Rouffineau, F.; Saulnier, L.; Giardina, T.; Bonnin, E.; Preynat, A. In Vitro Gastrointestinal Digestion Study of Two Wheat Cultivars and Evaluation of Xylanase Supplementation. J. Anim. Sci. Biotechnol. 2015, 6, 5–19. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  35. Liaud, N.; Giniés, C.; Navarro, D.; Fabre, N.; Crapart, S.; Gimbert, I.-H.; Levasseur, A.; Raouche, S.; Sigoillot, J.-C. Exploring Fungal Biodiversity: Organic Acid Production by 66 Strains of Filamentous Fungi. Fungal Biol. Biotechnol. 2014, 1, 1. [Google Scholar] [CrossRef] [Green Version]
  36. Gupta, V.K.; Kubicek, C.P.; Berrin, J.-G.; Wilson, D.W.; Couturier, M.; Berlin, A.; Filho, E.X.F.; Ezeji, T. Fungal Enzymes for Bio-Products from Sustainable and Waste Biomass. Trends Biochem. Sci. 2016, 41, 633–645. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  37. White Bruns, T.; Lee, S.; Taylor, J.; White, T.J.; Bruns, T.D.; Lee, S.B.; Taylor, J.W. Amplification and direct sequencing of fungal ribosomal RNA Genes for phylogenetics. In PCR Protocols; Academic Press Inc.: Cambridge, MA, USA, 1990; pp. 315–322. [Google Scholar]
  38. Lesage-Meessen, L.; Lomascolo, A.; Bonnin, E.; Thibault, J.-F.; Buleon, A.; Roller, M.; Asther, M.; Record, E.; Ceccaldi, B.C.; Asther, M. A Biotechnological Process Involving Filamentous Fungi to Produce Natural Crystalline Vanillin from Maize Bran. Appl. Biochem. Biotechnol. 2002, 102–103, 141–153. [Google Scholar] [CrossRef]
  39. Navarro, D.; Couturier, M.; Damasceno da Silva, G.G.; Berrin, J.-G.; Rouau, X.; Asther, M.; Bignon, C. Automated Assay for Screening the Enzymatic Release of Reducing Sugars from Micronized Biomass. Microb. Cell Fact. 2010, 9, 58. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  40. Bradford, M.M. A Rapid and Sensitive Method for the Quantitation of Microgram Quantities of Protein Utilizing the Principle of Protein-Dye Binding. Anal. Biochem. 1976, 72, 248–254. [Google Scholar] [CrossRef]
  41. Sashidhar, R.B.; Capoor, A.K.; Ramana, D. Quantitation of ϵ-Amino Group Using Amino Acids as Reference Standards by Trinitrobenzene Sulfonic Acid: A Simple Spectrophotometric Method for the Estimation of Hapten to Carrier Protein Ratio. J. Immunol. Methods 1994, 167, 121–127. [Google Scholar] [CrossRef]
  42. Englyst, H.N.; Cummings, J.H. Improved Method for Measurement of Dietary Fiber as Non-Starch Polysaccharides in Plant Foods. J. Assoc. Off. Anal. Chem. 1988, 71, 808–814. [Google Scholar] [CrossRef]
  43. Blumenkrantz, N.; Asboe-Hansen, G. New Method for Quantitative Determination of Uronic Acids. Anal. Biochem. 1973, 54, 484–489. [Google Scholar] [CrossRef]
  44. Mohnen, D. Pectin Structure and Biosynthesis. Pectin Structure and Biosynthesis. Curr. Opin. Plant Biol. 2008, 11, 266–277. [Google Scholar] [CrossRef]
  45. Huisman, M.M.H.; Schols, H.A.; Voragen, A.G.J. Cell Wall Polysaccharides from Soybean (Glycine Max.) Meal. Isolation and Characterisation. Carbohydr. Polym. 1998, 37, 87–95. [Google Scholar] [CrossRef]
  46. Nakamura, A.; Furuta, H.; Maeda, H.; Takao, T.; Nagamatsu, Y. Structural Studies by Stepwise Enzymatic Degradation of the Main Backbone of Soybean Soluble Polysaccharides Consisting of Galacturonan and Rhamnogalacturonan. Biosci. Biotechnol. Biochem. 2002, 66, 1301–1313. [Google Scholar] [CrossRef] [PubMed]
  47. Huisman, M.M.H.; Schols, H.A.; Voragen, A.G.J. Enzymatic Degradation of Cell Wall Polysaccharides from Soybean Meal. Carbohydr. Polym. 1999, 38, 299–307. [Google Scholar] [CrossRef]
  48. Luis, A.S.; Briggs, J.; Zhang, X.; Farnell, B.; Ndeh, D.; Labourel, A.; Baslé, A.; Cartmell, A.; Terrapon, N.; Stott, K.; et al. Dietary Pectic Glycans Are Degraded by Coordinated Enzyme Pathways in Human Colonic Bacteroides. Nat. Microbiol. 2018, 3, 210–219. [Google Scholar] [CrossRef] [PubMed]
  49. Azadi, P.; O’Neill, M.A.; Bergmann, C.; Darvill, A.G.; Albersheim, P. The Backbone of the Pectic Polysaccharide Rhamnogalacturonan I Is Cleaved by an Endohydrolase and an Endolyase. Glycobiology 1995, 5, 783–789. [Google Scholar] [CrossRef] [PubMed]
  50. De Vries, R.P. Regulation of Aspergillus Genes Encoding Plant Cell Wall Polysaccharide-Degrading Enzymes; Relevance for Industrial Production. Appl. Microbiol. Biotechnol. 2003, 61, 10–20. [Google Scholar] [CrossRef]
  51. Silva, I.R.; Jers, C.; Meyer, A.S.; Mikkelsen, J.D. Rhamnogalacturonan I Modifying Enzymes: An Update. Nat. Biotechnol. 2016, 33, 41–54. [Google Scholar] [CrossRef]
  52. Lemaire, A.; Duran Garzon, C.; Perrin, A.; Habrylo, O.; Trezel, P.; Bassard, S.; Lefebvre, V.; Van Wuytswinkel, O.; Guillaume, A.; Pau-Roblot, C.; et al. Three Novel Rhamnogalacturonan I- Pectins Degrading Enzymes from Aspergillus Aculeatinus: Biochemical Characterization and Application Potential. Carbohydr. Polym. 2020, 248, 116752. [Google Scholar] [CrossRef]
  53. De Vries, R.P.; Jansen, J.; Aguilar, G.; Parenicová, L.; Joosten, V.; Wülfert, F.; Benen, J.A.E.; Visser, J. Expression Profiling of Pectinolytic Genes from Aspergillus niger. FEBS Lett. 2002, 530, 41–47. [Google Scholar] [CrossRef] [Green Version]
  54. Bilal, M.; Mirza, M.A.; Kaleem, M.; Saeed, M.; Reyad-Ul-Ferdous, M.; Abd El-Hack, M.E. Significant Effect of NSP-Ase Enzyme Supplementation in Sunflower Meal-Based Diet on the Growth and Nutrient Digestibility in Broilers. J. Anim. Physiol. Anim. Nutr. 2017, 101, 222–228. [Google Scholar] [CrossRef]
Figure 1. Evaluation of the fungal growth on soybean meal. Panel (A): schematic description of the parameters used to select the best-performing strains. Panels (B,C): examples with growth of Oxyporus latemarginatus BRFM 678 (B) and Absidia glauca BRFM 2463 (C). composition of the petri dishes: from the top left-hand corner to the bottom right-hand corner: agar medium, PDA or MA2 medium, soybean meal (SBM)-composed medium, recalcitrant SBM-composed medium.
Figure 1. Evaluation of the fungal growth on soybean meal. Panel (A): schematic description of the parameters used to select the best-performing strains. Panels (B,C): examples with growth of Oxyporus latemarginatus BRFM 678 (B) and Absidia glauca BRFM 2463 (C). composition of the petri dishes: from the top left-hand corner to the bottom right-hand corner: agar medium, PDA or MA2 medium, soybean meal (SBM)-composed medium, recalcitrant SBM-composed medium.
Jof 07 00278 g001
Figure 2. Schematic representation of the method to assay SBM degradation. The bar chart shows the method validation using the Rovabio® enzymatic cocktail (0.9 mg of enzyme) and a serine-protease preparation (10 mg). Error bars indicate standard deviations of triplicate independent experiments.
Figure 2. Schematic representation of the method to assay SBM degradation. The bar chart shows the method validation using the Rovabio® enzymatic cocktail (0.9 mg of enzyme) and a serine-protease preparation (10 mg). Error bars indicate standard deviations of triplicate independent experiments.
Jof 07 00278 g002
Figure 3. Ability of each secretome to hydrolyze soybean meal. Soybean meal solubilization was deduced from dry matter measurements (see Material and Methods). For each condition, 0.1 mg of each secretome’s enzymes was added. Ag: Absidia glauca, Gj: Gymnopilus junonius, Le: Lentinula edodes, At: Aspergillus terreus, and Aj: Aspergillus japonicus. Of note, Gj SBP data are missing as the secretome was too viscous and could not be collected and processed. Error bars indicate standard deviations of triplicate independent experiments. Significance of the results between “No enzyme” and secretome addition was assessed using t-test (n = 3) with p-value: *, p-value < 0.05; ** p-value < 0.01.
Figure 3. Ability of each secretome to hydrolyze soybean meal. Soybean meal solubilization was deduced from dry matter measurements (see Material and Methods). For each condition, 0.1 mg of each secretome’s enzymes was added. Ag: Absidia glauca, Gj: Gymnopilus junonius, Le: Lentinula edodes, At: Aspergillus terreus, and Aj: Aspergillus japonicus. Of note, Gj SBP data are missing as the secretome was too viscous and could not be collected and processed. Error bars indicate standard deviations of triplicate independent experiments. Significance of the results between “No enzyme” and secretome addition was assessed using t-test (n = 3) with p-value: *, p-value < 0.05; ** p-value < 0.01.
Jof 07 00278 g003
Figure 4. Ability of each secretome to supplement the Rovabio® enzymatic cocktail. Rovabio® (0.9 mg of enzyme) was supplemented with 0.4 mg of enzyme from the produced secretomes. Ag: Absidia glauca, Gj: Gymnopilus junonius, Le: Lentinula edodes, At: Aspergillus terreus, Aj: Aspergillus japonicus, SBP: sugar beet pulp, and SBM: soybean meal. Gj SBP data are missing as the secretome was too viscous and could not be collected and processed. Error bars indicate standard deviations of triplicate independent experiments. Significance of the results between Rovabio® condition and Rovabio® supplementation with secretome was assessed using t-test (n = 3) with p-value: *, p-value < 0.05; ** p-value < 0.01.
Figure 4. Ability of each secretome to supplement the Rovabio® enzymatic cocktail. Rovabio® (0.9 mg of enzyme) was supplemented with 0.4 mg of enzyme from the produced secretomes. Ag: Absidia glauca, Gj: Gymnopilus junonius, Le: Lentinula edodes, At: Aspergillus terreus, Aj: Aspergillus japonicus, SBP: sugar beet pulp, and SBM: soybean meal. Gj SBP data are missing as the secretome was too viscous and could not be collected and processed. Error bars indicate standard deviations of triplicate independent experiments. Significance of the results between Rovabio® condition and Rovabio® supplementation with secretome was assessed using t-test (n = 3) with p-value: *, p-value < 0.05; ** p-value < 0.01.
Jof 07 00278 g004
Figure 5. Effect of the Aspergilli secretomes on the protein and sugar release from soybean meal. Panel (A): soybean meal solubilization after supplementation of Rovabio® with different amounts of enzymes for Aspergillus terreus (At) and Aspergillus japonicus (Aj) secretomes. Panel (B): total amount of released proteins (blue) and proteolytic digestion (red) after supplementation of Rovabio® with different amounts of enzymes for Aspergillus secretomes. Panel (C): total amount of released sugars after supplementation of Rovabio® with different amounts of enzymes from Aspergillus secretomes. Error bars indicate standard deviations of triplicate independent experiments. The significance of the results between Rovabio® condition and Rovabio® supplementation with secretome was assessed using t-test (n = 3). The p-value (**) obtained was <0.01 for all the results except for proteolytic digestion in the case of Rovabio® supplemented with 0.45 mg Aj Panel (B).
Figure 5. Effect of the Aspergilli secretomes on the protein and sugar release from soybean meal. Panel (A): soybean meal solubilization after supplementation of Rovabio® with different amounts of enzymes for Aspergillus terreus (At) and Aspergillus japonicus (Aj) secretomes. Panel (B): total amount of released proteins (blue) and proteolytic digestion (red) after supplementation of Rovabio® with different amounts of enzymes for Aspergillus secretomes. Panel (C): total amount of released sugars after supplementation of Rovabio® with different amounts of enzymes from Aspergillus secretomes. Error bars indicate standard deviations of triplicate independent experiments. The significance of the results between Rovabio® condition and Rovabio® supplementation with secretome was assessed using t-test (n = 3). The p-value (**) obtained was <0.01 for all the results except for proteolytic digestion in the case of Rovabio® supplemented with 0.45 mg Aj Panel (B).
Jof 07 00278 g005aJof 07 00278 g005b
Figure 6. Effect of the Aspergillus terreus secretomes produced in bioreactor on the protein and sugars released from soybean meal. Panel (A): soybean meal solubilization after hydrolysis. F1, F2, and F3 are secretomes from Aspergillus terreus produced in bioreactors (experimental conditions in Table S2). Panel (B): total amount of released proteins (blue) and proteolytic digestion (red) after supplementation of Rovabio® with A. terreus secretomes produced in flask. Panel (C): soluble sugars released after SBM hydrolysis by Rovabio® supplemented with the A. terreus secretomes produced in bioreactor. Error bars indicate standard deviations of triplicate independent experiments. The significance of the results between Rovabio® condition and Rovabio® supplementation with secretomes (Flask and F1, F2, F3 bioreactors) was assessed using t-test (n = 3). The p-value obtained was <0.01 (**) for all the results.
Figure 6. Effect of the Aspergillus terreus secretomes produced in bioreactor on the protein and sugars released from soybean meal. Panel (A): soybean meal solubilization after hydrolysis. F1, F2, and F3 are secretomes from Aspergillus terreus produced in bioreactors (experimental conditions in Table S2). Panel (B): total amount of released proteins (blue) and proteolytic digestion (red) after supplementation of Rovabio® with A. terreus secretomes produced in flask. Panel (C): soluble sugars released after SBM hydrolysis by Rovabio® supplemented with the A. terreus secretomes produced in bioreactor. Error bars indicate standard deviations of triplicate independent experiments. The significance of the results between Rovabio® condition and Rovabio® supplementation with secretomes (Flask and F1, F2, F3 bioreactors) was assessed using t-test (n = 3). The p-value obtained was <0.01 (**) for all the results.
Jof 07 00278 g006aJof 07 00278 g006b
Table 1. Fungal strains selected for the functional screening.
Table 1. Fungal strains selected for the functional screening.
Species NameBRFM NumberPhylumFamily
Absidia glauca2463MucoromycotaCunninghamellaceae
Amauroderma calcigenum1190BasidiomycotaGanodermataceae
Artolenzites elegans1280BasidiomycotaPolyporaceae
Aspergillus japonicus405AscomycotaTrichocomaceae
Aspergillus terreus111AscomycotaTrichocomaceae
Atheloderma mirabile2371BasidiomycotaHymenochaetales
Bjerkandera adusta274BasidiomycotaMeruliaceae
Ceriporiopsis rivulosa663BasidiomycotaPhanerochaetaceae
Ceriporiopsis subvermispora394BasidiomycotaPhanerochaetaceae
Colletotrichum theobromicola1632AscomycotaGlomerellaceae
Coniochaeta rubrosetosa1331AscomycotaConiochaetaceae
Coniophora arida494BasidiomycotaConiophoraceae
Cookeina sulcipes2338AscomycotaSarcoscyphaceae
Crustomyces subabruptus793BasidiomycotaCystostereaceae
Cyclocybe aegerita493BasidiomycotaBolbitiaceae
Dichostereum effuscatum91BasidiomycotaLachnocladiaceae
Eutypella scoparia1012AscomycotaDiatrypaceae
Fomitiporia mediterranea2470BasidiomycotaHymenochaetaceae
Fomitopsis pinicola886BasidiomycotaFormitopsidaceae
Gloeophyllum odoratum1454BasidiomycotaGloephyllaceae
Gymnopilus junonius969BasidiomycotaCortinariaceae
Hericium coralloides807BasidiomycotaHericiaceae
Heterobasidion annosum238BasidiomycotaBondarzewiaceae
Hypomyces luteovirens1580AscomycotaHypocreaceae
Laetisaria arvalis512BasidiomycotaCorticiaceae
Lentinellus castoreus668BasidiomycotaAuriscalpiaceae
Lentinula edodes353BasidiomycotaMarasmiaceae
Lepista nuda845BasidiomycotaTricholomataceae
Lophiostoma arundinis1636AscomycotaLophiostomataceae
Macrolepiota fuliginosa851BasidiomycotaAgaricaceae
Mortierella alpina2447MucoromycotaMorcierellaceae
Mycosphaerella lateris1628AscomycotaMycosphaerella
Nectria pseudotrichia1017AscomycotaNectriaceae
Neurospora crassa1092AscomycotaSordariaceae
Oxyporus latemarginatus678BasidiomycotaMeruliaceae
Peniophora albobadia788BasidiomycotaPeniophoraceae
Pestalotiopsis sp1648AscomycotaAmphisphaeriaceae
Phaeosphaeria spartinicola1633AscomycotaPhaeosphariaceae
Phanerochaete chrysosporium276BasidiomycotaPhanerochaetaceae
Phycomyces blakesleeanus1098MucoromycotaPhycomycetaceae
Pleospora leptosphaerulinoides2474AscomycotaPleosporaceae
Pleurotus ostreatus853BasidiomycotaPleurotaceae
Podospora anserina977AscomycotaLasiosphaeriaceae
Pycnoporus sanguineus902BasidiomycotaPolyporaceae
Rhizoctonia solani2454BasidiomycotaCeratobasidiaceae
Rhizopus arrhizus var. arrhizus1095MucoromycotaMucoraceae
Sinosphaeria bambusicola1245AscomycotaThyrdiaceae
Sistotrema coroniferum803BasidiomycotaHydnaceae
Xylobolus frustulatus768BasidiomycotaStereaceae
Table 2. Compositional analysis of the residual dry matter sugar content after hydrolysis. SBM was hydrolyzed with Rovabio®, supplemented or not with Aspergillus terreus or Aspergillus japonicus secretome grown on SBP (0.45 mg of enzyme). The residual dry matter sugar composition was analyzed. Rha: rhamnose, Fuc: fucose, Ara: arabinose, Xyl: Xylose, Man: mannose, Gal: galactose, Glc: glucose, and UA: uronic acids. Standard deviations of triplicate independent experiments are indicated. Significance of the results between Rovabio® condition and Rovabio® supplementation with secretome was assessed using t-test (n = 3) with p-value: * p-value < 0.05; ** p-value < 0.01, both indicated by an arrow.
Table 2. Compositional analysis of the residual dry matter sugar content after hydrolysis. SBM was hydrolyzed with Rovabio®, supplemented or not with Aspergillus terreus or Aspergillus japonicus secretome grown on SBP (0.45 mg of enzyme). The residual dry matter sugar composition was analyzed. Rha: rhamnose, Fuc: fucose, Ara: arabinose, Xyl: Xylose, Man: mannose, Gal: galactose, Glc: glucose, and UA: uronic acids. Standard deviations of triplicate independent experiments are indicated. Significance of the results between Rovabio® condition and Rovabio® supplementation with secretome was assessed using t-test (n = 3) with p-value: * p-value < 0.05; ** p-value < 0.01, both indicated by an arrow.
Massic%
Rovabio®Rovabio® + AjRovabio® + At
Rha0.315 ± 0.0070.375 ± 0.0260.315 ± 0.071
Fuc0.450 ± 0.0280.414 ± 0.360 0.298 ± 0.061 ↘ *
Ara1.644 ± 0.1991.030 ± 0.065 0.882 ± 0.106 ↘ **
Xyl1.909 ± 0.0702.220 ± 0.218 1.158 ± 0.269 ↘ *
Man1.136 ± 0.1020.915 ± 0.1220.853 ± 0.165
Gal1.742 ± 0.082 1.231 ± 0.104 ↘ ** 0.794 ± 0.078 ↘ **
Glc6.531 ± 0.8415.288 ± 0.249 3.468 ± 0.544 ↘ **
UA5.687 ± 0.2067.154 ± 0.097 4.163 ± 0.334 ↘ **
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Grandmontagne, D.; Navarro, D.; Neugnot-Roux, V.; Ladevèze, S.; Berrin, J.-G. The Secretomes of Aspergillus japonicus and Aspergillus terreus Supplement the Rovabio® Enzyme Cocktail for the Degradation of Soybean Meal for Animal Feed. J. Fungi 2021, 7, 278. https://doi.org/10.3390/jof7040278

AMA Style

Grandmontagne D, Navarro D, Neugnot-Roux V, Ladevèze S, Berrin J-G. The Secretomes of Aspergillus japonicus and Aspergillus terreus Supplement the Rovabio® Enzyme Cocktail for the Degradation of Soybean Meal for Animal Feed. Journal of Fungi. 2021; 7(4):278. https://doi.org/10.3390/jof7040278

Chicago/Turabian Style

Grandmontagne, Delphine, David Navarro, Virginie Neugnot-Roux, Simon Ladevèze, and Jean-Guy Berrin. 2021. "The Secretomes of Aspergillus japonicus and Aspergillus terreus Supplement the Rovabio® Enzyme Cocktail for the Degradation of Soybean Meal for Animal Feed" Journal of Fungi 7, no. 4: 278. https://doi.org/10.3390/jof7040278

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop