Standardized ileal digestibility of amino acids in soybean meal fed to non-pregnant and pregnant sows

Background Two studies were designed to determine standard ileal crude protein(CP)and amino acid(AA)digestibility of soybean meal(SBM)from different origins fed to non-pregnant and pregnant sows.Seven solvent-extracted SBMs from soybeans produced in the USA,Brazil,and China were selected.In Exp.1,eight different diets were created:a nitrogen(N)-free diet and 7 experimental diets containing SBM from different origins as the only N source.Eight non-pregnant,multiparous sows were arranged in an 8×8 Latin square design(8 periods and 8 diets).In Exp.2,the diet formula was the same as in Exp.1.Eight gestating sows(parity 3)were assigned to 4 different diets in a replicated 4×3 Youden square design(three periods and four diets)in mid-gestation and again in late-gestation stages.Results When fed to non-pregnant and late-gestating sows,the standardized ileal digestibility(SID)of CP and most AAs from different SBM were not significantly different(P>0.05).When fed to mid-gestating sows,the SID values for Arg,His,Lys,Phe,Cys,Gly,Ser,and Tyr in SBM 1 were lower than in SBM 4 and 5(P<0.05),whereas SID for Leu from SBM 5 was higher than in SBM 1 and 4(P<0.05).SID values for Ile,Ala,and Asp from SBM 4 were lower than in SBM 1 and 5(P<0.05).Sows had significantly greater SID values for Lys,Ala,and Asp during mid-gestation when compared with late-gestation stages(P<0.05).Mid-gestating sows had greater SID value for Val and lower SID value for Tyr when compared with non-pregnant and late-gestating sows(P<0.01),whereas non-pregnant sows had significantly greater SID value for Met when compared with gestating sows(P<0.01).Conclusions When fed to mid-gestating sows,the SID values for most AAs varied among SBM samples.The SID values for Lys,Met,Val,Ala,Asp,and Tyr in SBM were affected by sow gestation stages.Our findings provide a cornerstone for accurate SBM use in sow diets.

Optimization of Solid-State Fermentation with Lactobacillus brevis and Aspergillus oryzae for Trypsin Inhibitor Degradation in Soybean Meal

The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on phytic acid, crude protein, crude fat, and amino acid profile. Response surface methodology （RSM） with Box-Behnken design was used to optimize SSF. The optimal conditions derived from RSM for L. brevis fermentation were： pH=5. 1; inoculum size=10%; duration=72 h; substrate to water ratio=1.5. The minimum content of trypsin inhibitors was 6.4 mg g^-1 dry matter. The optimal conditions derived from RSM for A. oryzae fermentation were： substrate to water ratio= 0.8 1; inoculum size=4%; duration=120 h. The minimum content of trypsin inhibitors was 1.6 mg g^-1 dry matter. Both L. brevis and A. oryzae decreased trypsin inhibitors dramatically （57.1 and 89.2% respectively）. L. brevis fermentation did not affect phytic acid （0.4%） and crude fat （5.2%） considerably, whereas A. oryzae fermentation degraded phytic acid （34.8%） and crude fat （22.0%） contents to a certain extent. Crude protein content was increased after both fermentation （6.4 and 12.9% for L. brevis and A. oryzae respectively）. Urease activity was reduced greatly （83.3 and 58.3% for L. brevis and A. oryzae respectively）. In conclusion, SSF with A. oryzae and L. brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.

Effects of Brown Fish Meal Replacement with Fermented Soybean Meal on Growth Performance, Feed Efficiency and Enzyme Activities of Chinese Soft-shelled Turtle, Pelodiscus sinensis

A 120-day feeding experiment was conducted to investigate the effects of partial replacement of brown fish meal (BFM) by fermented soybean meal (FSBM) in diets of Chinese soft-shelled turtle (Pelodiscus sinensis). The turtles (initial mean body weight, (115.52 ± 1.05) g) were fed with three experimental diets, in which 0%, 4.72% and 9.44% BFM protein was replaced by 0%, 3% and 6% FSBM, respectively. Results showed that the feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) of turtles fed with the diet containing 3% FSBM were not significantly different from the control group (0% FSBM) (P > 0.05). However, FR, SGR and FER of turtles fed with the diet containing 6% FSBM were significantly lower than those of the control group (P < 0.05). No significant differences were observed in the activities of serum glutamic-oxalacetic transaminase and glutamicpyruvic transaminase among dietary treatments (P > 0.05). However, the uric acid concentration in turtles fed with the diet containing 3% or 6% FSBM was significantly lower than that in the control group (P < 0.05). There were no significant differences in the activities of lysozyme, alkaline phosphatase and total superoxide dismutase among dietary treatments (P > 0.05). The results suggested that FSBM could replace 4.72% BFM protein in turtle diets without exerting adverse effects on turtle growth, feed utilization and measured immune parameters.

Effect of Replacing Fish Meal with Extruded Soybean Meal on Growth, Feed Utilization and Apparent Nutrient Digestibility of Juvenile White Shrimp(Litopenaeus vannamei)

Extruded soybean meal （ESBM） was evaluated as a protein source for partial replacement of fish meal （FM） in diets of juvenile Litopenaeus vannarnei. In the control diet （Diet 1）, FM protein was replaced with increasing dietary levels of ESBM （4.28%, 8.40%, 12.62%, 16.82%, and 25.26%） at 10%, 20%, 30%, 40%, and 60% levels （Diets 2 to 6, respectively）. An eight-week feeding trial was conducted on 720 juvenile shrimp （0.67 g ± 0.01 g mean initial Weight）, and nutrient digestibility of the six diets was determined. ESBM could replace 20% of FM without causing a significant reduction in growth of shrimp, but other dietary treatments strongly affected whole body composition. Crude protein content of the whole body fed Diet 6 was significantly lower than that fed Diet 2 （P〈0.05）, while crude lipid content of the whole body fed Diet 5 or 6 was significantly higher than that fed Diet 2 （P〈0,05）. Protein digestibilities of Diets 5 and 6 were significantly lower than that of Diet 1 （P〈0.05）. Digestibility of lipids ranged from 96.97% in Diet 6 to 98.34% in Diet 3, whereas dry matter digestibility decreased with increasing replacement level. This study indicates that 20% FM replacement with ESBM in the basic diet containing 40% protein and 30% FM is optimal for juvenile L. vannamei.

Study on Lysine and Methionine Content Promotion of Soybean Meal by Probiotic Fermentation Process

Soybean meal （SBM） is commonly used for livestock feeds, but its application in diets for livestock is limited due to some antinutritional factors. The contents of methionine and lysine of soybean meal were promoted by Bacillus natto and Leuconostoc mesenteroides fermentation, benefial for the livestock feeds. It was crude protein （CP） 56.8%, methionine 43.56 mg · g^-1, and lysine 74.87 mg · g^-1, cows fed a diet with FSBM milk yield raised 14.2%, the change in the milk protein, the lactose and the dry matter content had also obvious increase. This convenient technique offers helpful exploration for industrialization of soybean meal fermentation.

Comparative effects of soy protein concentrate,enzyme‑treated soybean meal,and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

Estimate of the energy value of soybean meal relative to corn based on growth performance of nursery pigs

Background:Two experiments were conducted to determine the effects of increasing amounts of soybean meal(SBM)in swine diets and estimate the energy value of SBM.Methods:A total of 2233 pigs(PIC 337×1050,Hendersonville,TN)and 3796 pigs(PIC 359×C40),initially 11.0 kg and 17.6 kg body weight(BW),were used in Exp.1 and 2,respectively.In Exp.1,pigs were placed in 92 pens each containing 20 to 27 pigs.In Exp.2,pigs were placed in 84 pens each containing 37 to 43 pigs.Treatments were assigned in a randomized complete block design with BW as the blocking factor.Dietary treatments consisted of 21%,27%,33%,or 39%SBM in Exp.1 and 17.5%,22%,26.5%,31%,35.5%,or 40%SBM in Exp.2,obtained by changing the inclusion rate of feed-grade amino acids and corn grain.For Exp.1,representative samples of corn grain,SBM,and distillers dried grains with solubles were analyzed for total AA content prior to diet formulation.For Exp.2,diets were formulated using NRC(2012)nutrient loadings.Treatment diets were fed for 21 and 22 d(Exp.1 and 2)and there were 23 replicates in Exp.1 and 14 replicates in Exp.2.Pigs were weighed and feed disappearance measured weekly to calculate average daily gain(ADG),average daily feed intake(ADFI),gain-to-feed ratio(G:F),and caloric efficiency(CE).Data were analyzed with block as a random effect and treatment as a fixed effect,and contrasts were constructed to test the linear and quadratic effects of increasing SBM.Results:In Exp.1,there was a tendency(linear,P=0.092)for a decrease in ADFI as SBM increased.There was a tendency(P=0.090)for a quadratic response for ADG,with a decrease in ADG observed with 39%SBM inclusion.Pigs fed diets with increasing SBM had a tendency(quadratic,P=0.069)for an increase in G:F up to 33%SBM and an improvement(linear,P=0.001;quadratic,P=0.063)in CE with increasing SBM.Using CE to estimate the energy of SBM relative to corn,a value of 105.4%of corn energy or 2816 kcal/kg NE was determined using all data points.When removing the CE value of the 39%SBM treatment due to the quadratic tendency,SBM was estimated to have 121.1%of corn energy or 3236 kcal/kg NE.In Exp.2,there was a decrease(linear,P=0.001)in ADFI.Pigs fed increasing SBM had a tendency(linear,P=0.065)for reduced ADG but an improvement(linear,P=0.001)in G:F and CE as SBM increased.The energy value of SBM was estimated as 124.7%of corn energy or 3332 kcal/kg NE.Conclusions:The results suggest that feeding increasing levels of SBM improves G:F and CE.The energy value of SBM was estimated to be between 105%and 125%of corn,which is much greater than the NRC(2012)would indicate.

Effects of dietary replacement of soybean meal with dried distillers grains with solubles on the microbiota occupying different ecological niches in the rumen of growing Hu lambs

Background:Diet has a profound impact on the rumen microbiota,and the impact can vary among the different rumen ecological niches(REN).This study investigated the effects of dietary replacement of soybean meal(SBM)with dried distillers grains with solubles(DDGS)on the rumen microbiota occupying different REN of growing Hu lambs.After a 9-week feeding trial,6 lambs from each dietary treatment(SBM vs.DDGS-based diets)were slaughtered for sample collection.The microbiota of the rumen solid,liquid,and epithelium fractions was examined using amplicon sequencing analysis of bacterial 16S rRNA gene,functional prediction,and qPCR.Results:No interaction of dietary protein source(PS)and REN were detected for virtually all the measurements made in this study.The DDGS substitution resulted in very limited influence on bacterial community structure.However,the metabolic pathways predicted from 16S rRNA gene sequences varied greatly between SBM-and DDGS-based diets.The populations of rumen total bacteria,fungi,sulfate-reducing bacteria(SRB),and methanogens were not influenced by DDGS substitution,but the population of protozoa was reduced.The bacterial communities in rumen solid(RS)and liquid(RL)were similar in taxonomic composition but were different in relative abundance of some taxa.In contrast,the bacterial composition and relative abundance of rumen epithelium(RE)were greatly distinct from those of the RS and the RL.In alignment with the bacterial relative abundance,the metabolic pathways predicted from 16S rRNA genes also varied greatly among the different REN.The populations of total bacteria,protozoa,and methanogens attached to the RE were smaller than those in the RS and RL,and the fungal population on the rumen epitheliumwas smaller than that in the RS but similar to that in the RL.On the contrary,the SRB population on the RE was greater than that in the RS and RL.Conclusions:Substitution of SBM with DDGS had greater impact to the protozoa than to the other microbes,and the microbial community structure and functions at different REN are distinct and niche-adapted.

Concerns about the misleading conclusions regarding estimation of the net energy value of soybean meal relative to corn using the caloric efficiency approach in pigs

Apart from energy balance trials such as calorimetry,growth trials could also be used to estimate the energy values of feed ingredients with caloric efficiency as an indicator.Recent work used such methods reported greater net energy(NE)value of soybean meal(SBM)relative to corn in nursery pigs.We theoretically compared the NE values of SBM and corn according to the definition of NE and properties of the major chemical compositions in each ingredient.Meanwhile,we thoroughly examined the diet formulations and related analysis used in this work and compared this study with some peer works.We found that this study may suffer from problems with experimental design,reference citation,and data interpretation.In summary,the conclusion from the recent work that the SBM NE value may be greater than the corn NE value is likely to be erroneous.

Possible Mechanism Associated with Herbicidal Activity of Soybean Meal Hydrolysate (SMH)

Soybean meal hydrolyzate （SMH） has been proposed for use as a natural preemergence herbicide.However,the mechanism by which SMH exerts its herbicidal activity remains unclear.In this paper,the herbicidal activities of SMH against perennial ryegrass （Lolium perenne L.） under non-sterile and sterile conditions were evaluated and the relationship between the molecular weight of the ultrafiltration （UF） fractions of SMH and their herbicidal activities were investigated.Besides,the ammonia content changes of the media of SMH treatments 7 d after incubation were also analyzed.The results showed that SMH inhibited the radicle growth of germinating L.perenne seeds in a dose-dependent manner under non-sterile condition.However,SMH in the concentrations investigated increased the radicle length and shoot length by 14-17% and 11-15% respectively under sterile condition.The ammonia contents in the SMH media at all treatments increased greatly from less than 0.01 mg L-1 to up to 11.86-41.37 mg L-1 after 7 d incubation under non-sterile condition.However,ammonia content did not change under sterile condition,proposing that the herbicidal activity might be caused by the free ammonia released from SMH by microbial activity.There was no difference on the perennial ryegrass radicle inhibition among the UF fractions of SMH on an equivalent N basis.It could be concluded that SMH exerted its herbicidal activity through the free ammonia released under non-sterile condition instead of by specific peptide（s） in SMH.

The Effect of Soybean Meal Fermented by Aspergillus usami on Phosphor Metabolism in Growing Pigs

[Objective] The experiment aimed to check the pigs＇ digestive utilization of phosphor and other nutrient components in fermented soy- bean meal. [ Method] 15 8-week old two-way cross growing pigs （average weight was 23.6 kg） were selected and divided randomly into 3 groups, 5 pigs per group. The method of total feces collection was adopted to compare the digestibility of phosphor and other nutrient components in growing pigs fed respectively by fermented soybean meal by Aspergillus usami and normal soybean meal. The experimental design were normal soybean group （NS group, P： 0.087%）, fermented soybean meal group （FS group, P： 0.089%）, normal soybean ＋ fermented soybean meal mixing group （ MS group, P： 0.089% ）. [ Result] The results indicated that the digestibility of growing pigs in FS group was significantly higher than that of NS group. Meanwhile, the digestibility of crude protein was significantly improved. [ Conclusion] The above results indicated that Feeding with soybean meal fermented by Aspergillus usami not only could increase the digestibility of phosphor and protein, but also decrease the excretion of phosphor and nitrogen.

Prediction of net energy value of corn and soybean meal for broiler chicken

Net energy （NE） is the most accurate and unbiased way in characterizing the energy content of feed. Comparatively speaking, research on NE prediction is still limited and under development. Therefore, it is important to correctly assess NE for further study. In this study, an energy balance trial and a fasting metabolism trial were used to measure the net energy for production （NEp） and the net energy for maintenance （NEm）, respectively. Meanwhile, a backward method of multiple linear regression was applied to establish prediction equations for NE. The results showed that corn NE is about 2 times higher than that of soybean meal, due to the efficiency of ME （k） utilization by the ingredients. Meanwhile, AME and acid detergent fiber （ADF） were found to be better predictors for the NE of corn and soybean meal, respectively. Furthermore, Equations 1（R^2=0.993, RSD=0.0091） and 12 （R^2=0.999, RSD=0.0008） were found to be better prediction equations in multiple linear regression analyses for corn and soybean meal, respectively. However, considering the cost of the analytical procedures, the accuracy of the prediction （RSD）, and the additional variability or errors due to interlaboratory variance, Equation 4 （R^2=0.990, RSD=0.0109） and Equation 20 （R^2=0.996, RSD=0.0043） were better models for corn and soybean meal, respectively. Nevertheless, these equations for corn and soybean meal should be applied only under similar experimental conditions.

Rapid screening and visual tracing of melamine in soybean meal by NIR microscopy imaging

Near infrared microscopy imaging fers the opportunity to explore not only what lkinds ofchemical species are present at micro-scale level but also where the chemical species would bepr esent.By revealing the spectral and spatial information,the technique can identify and localizeany interested component.This study investigates the feasibility of using Near infrared mi.croscopy imaging to detect melamine in soybean meal.The results showed that 6805 cm^(-1) is verysensitive for melamine but not for soybean meal,so can be used for univariate analysis,Singlewavelength image and peak integr ation image at 6805 cm^(-1) are simple and efective met hods todetect the melamine in soybean meal.Furthermore,Principal Component Analysis is applied todetect the melamine in soybean meal.

Effect of Dietary Supplement, Base Mix, and/or Soybean Meal on Growing Pig Performance

A total of 60 crossbred pigs (Yorkshire × Duroc, initially 56.5 kg) were used in a 42-day trial to evaluate the effect of replacing a commercial high protein supplement with soybean meal and/or a base mix in rice bran-based diets on pig growth performance. Pigs were allotted to pens by body weight and pens were randomly assigned to dietary treatments in completely randomized design. There were 4 dietary treatments with 3 or 4 replicate pens per treatment and 4 pigs per pen. Dietary treatments were: 1) 80% rice bran with 20% high protein supplement (RBS20), 2) 95% rice bran with 5% high protein supplement (RBS5), 3) 97.5% rice bran with 2.5% base mix (RBB2.5), and 4) 92.5% rice bran with 5% soybean meal and 2.5% base mix (RBSBB). The base mix included vitamins, macro and trace minerals, L-Lysine, L-Threonine, and DL-Methionine. Overall (d 0 to 42) average daily gain was greater (P < 0.001) for pigs fed RBSBB and RBS20 diets than pigs fed the RBS5 or RBB2.5 diets. Pigs fed the RBS5 diet had reduced (P < 0.004) average daily feed intake compared to all other treatments. Similarly, feed efficiency (feed/gain) was improved (P < 0.004) for pigs fed RBSBB and RBS20 diets compared with pigs fed RBS5 or RBB2.5. For economics, income over feed cost was the greatest (P < 0.01) for the diet containing soybean meal and base mix compared to pigs fed the RBS20 diet, SBS5, and RBB2.5. In conclusion, feeding pigs a rice bran diet with base mix and soybean meal had similar growth performance and increased economic return compared to feeding a rice bran diet with high protein supplement. Use of soybean meal and base mix provides an opportunity for increased economic return for pig farmers.

Effect of Rice Bran Quality and Protein Supplement, Base Mix, and/or Soybean Meal on Growing Pig Performance in Cambodia

The objective of this study was to evaluate the effect of rice bran quality and dietary supplement source on growing pig performance. A total of 60 castrated male pigs (Yorkshire × Duroc, initially 16.1 kg) were used for 52-day trial. Pigs were allotted to pens in a completely randomized design (4 pigs per pen) and assigned to four dietary treatments in a 2 × 2 factorial with factors being rice bran source (high or low-quality) and source of protein, vitamins, and minerals (supplement or soybean meal and base mix). Analyzed protein and fat level for the high- and low-quality rice bran was 11.07% and 5.86% and 11.20% and 4.50%, respectively. Crude fiber content for high- and low-quality rice bran was 13.44% and 27.79%. Diets were formulated in two phases (phase 1: 16 to 27 and phase 2: 27 to 48 kg) to adjust to the pig’s nutrient requirements. There was no evidence for an interaction (P > 0.05) between rice bran quality × supplement type or main effect of supplement type (soybean meal + base mix vs protein supplement) for final body weight, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (F/G). However, pigs fed high-quality rice bran had improved (P < 0.001) ADG and F/G and lower ADFI compared to pigs fed low protein rice bran. In conclusion, rice bran quality as measured by protein, crude fiber, and fat influenced growing pig performance, while the type of dietary protein supplement did not. Additionally, rice bran with high protein, fat, and low fiber improved ADG and F/G.

Leucaena leucocephala Meal as Replacement to Soybean Meal in Growing Goat Diets

Eight goats of 7-8 months old and an average body weight （BW） of 20 ± 5.0 kg were used in double 4 × 4 Latin square design. The treatments were the four levels of leucaena meal replacement for soybean meal in concentrates at 0%, 25%, 50% and 75% of crude protein. The results showed that roughage intake （% BW and g/kgBW^0.75） increased linearly （P 〈 0.01） with increasing levels of leucaena meal while total feed intake was not significantly different among dietary treatments. Similarly, dry matter, organic matter, neutral detergent fiber digestibility and ruminal ammonia nitrogen （NH3-N） were not significantly different among dietary treatments. However, crude protein digestibility, ruminal pH （6 hr after feeding）, nitrogen （N） intake, N absorption, N retention and total volatile fatty acids increased quadratically （P 〈 0.01） with the increasing levels of leucaena meals. It could be concluded that leucaena meal could replace up to 50% of soybean meal in the diet without any negative effect on feed intake, nutrient digestibility and rumen fermentation of meat goats.

Separation and Identification of Glutamine Peptides from Defatted Soybean Meal by Enzymatic Hydrolysis

Glutamine peptides were obtained from defatted soybean meal by enzymatic hydrolysis using a combination of Protamex~? and trypsinase. The results showed that the extent of hydrolysis and the concentration of Gln peptides in the hydrolysate were 22.02%and 6.05 mmol/L, respectively. The hydrolysates were fractionated by size-exclusion chromatography on a Sephadex G-15 into five major fractions(GelF1–GelF5). The peptide(GelF1) fraction with the highest glutamine peptide content(51.8%) was further evaluated to determine its molecular weight distribution. Most(92.37%) peptides were less than 1 000 Da. Glutamic acid and glutamine were the most abundant amino acids, accounting for up to 12.98% of the total amino acid content. In addition, the total amino acid content in GelF1 was higher than that in GelF2 and GelF3.

Preparation of soybean meal peptide for chelation with copper/zinc using Aspergillus oryzae in solid-state fermentation

This study investigated the optimal process of solid-state fermentation(SSF)using soybean meal(SBM)as substrate by Aspergillus oryzae and proteolysis of SBM to prepare SBM-derived peptide(SBMP)for chelating with Cu(Ⅱ)/Zn(Ⅱ).During the SSF of SBM,the alkaline protease activity of A.oryzae was higher than that of two other fungi,reaching maximum activity(574 U/g)at the fermentation time of 86 h,43%inoculation ratio,and liq-uid-substrate(I/S)ratio of 0.8.The SBMP yield reached a maximum value at 55℃ for 6 h hydrolysis according to the analysis of the degree of hydrolysis(DH)and total Kjeldahl nitrogen(TKN)content in hydrolysates.After ultrafiltration,the SBMP of 1-5 kDa had the best ability to chelate with Cu(Ⅱ)and Zn(Ⅱ).Moreover,the SBMP displayed a higher capacity to chelate with Zn(Ⅱ)(222.7 mg/g)than Cu(Ⅱ)(68.3 mg/g)under optimal condi-tions.Aspartic acid,glutamic acid,lysine,arginine and histidine in SBMP played a critical role at the chelating Cu(Ⅱ)/Zn(Ⅱ).UV and FTIR spectrum analysis revealed that the-COOH and-NH_(2) in SBMP were the main bioactive groups for chelating with Cu(Ⅱ)/Zn(Ⅱ).SEM showed that the surface of SBMP-Cu(Ⅱ)/Zn(Ⅱ)chelate was rough and formed spherical aggregates.These results indicated that combining SSF and proteolysis exhibited great potential for preparing SBMP-metal chelates for developing organometallic supplements.

Poly-γ-glutamic acid-producing Bacillus velezensis fermentation can improve the feed properties of soybean meal

Soybean meal(SBM),a high-protein animal feed,contains several anti-nutritional factors,which limit its utilization.Poly-γ-glutamic acid(γ-PGA),a biological macromolecule,can significantly improve the health and growth benefits of animal feed.However,there are rare reports about SBM fermentation withγ-PGA-producing bacteria to improve its nutritional quality.In this study,we isolated a glutamic acid-independent polyγ-glutamic acid(γ-PGA)producing Bacillus velezensis SCP024-S-4 bacterial strain and used it for solid fermentation of SBM.The results showed that the maximumγ-PGA yield in fermented soybean meal(FSBM)reached up to 89.64 g/kg without adding glutamic acid.Meanwhile,the content of proteins,free amino acids and small peptides increased by 12.83%,347.96μg/g and 108.11 mg/g,respectively.Soy globulin,β-conglutinin and trypsin inhibitor all decreased below 3 mg/g.Mice were fed with CK(control diet),SBM and FSBM respectively.The average daily food intake in the FSBM,SBM,and CK groups were 7.68,5.25,and 6.36 g,respectively.Compared with the CK group,the mice weight growth rate was significantly higher in the FSBM group.Mice blood and spleen tests showed no negative effect of FSBM.The high-throughput sequencing of mice intestinal microflora indicated that FSBM increased the richness of intestinal microbiota;especially,the types and quantities of Lactobacillus were significantly increased.This study provides a feasible strategy to improve the nutritional quality of SBM as an animal feed.

Effects of undigested protein-rich ingredients on polarised small intestinal organoid monolayers

Here, we describe the use of monolayers of intestinal epithelial cells derived from intestinal organoids and transcriptomics to investigate the direct effects of dietary protein sources on epithelial function. Mechanically dissociated 3 D organoids of mouse duodenum were used to generate a polarized epithelium containing all cell types found in the tissue of origin. The organoid-derived cell monolayers were exposed to 4%(w/v) of ‘undigested(non-hydrolysed)-soluble' fraction of protein sources used as feed ingredients [soybean meal(SBM) and casein], or alternative protein sources(spray dried plasma protein, and yellow meal worm), or controls for 6 h prior to RNA isolation and transcriptomics. All protein sources altered expression of unique biological processes in the epithelial cells. Exposure of intestinal organoids to SBM downregulated expression of retinol and retinoid metabolic processes as well as cholesterol and lipid biosynthetic pathways, consistent with the reported hypotriglyceridaemic effect of soy protein in vivo. These findings support the use of intestinal organoids as models to evaluate complex interactions between dietary ingredients and the intestinal epithelium and highlights some unique host effects of alternative protein sources in animal feed and potentially human food.