Evaluation of the Available Energy Value and Amino Acid Digestibility of Brown Rice Stored for 6 Years and Its Application in Pig Diets.

Long-term storage may reduce the nutritional quality of brown rice, so the present study aimed to evaluate the nutritional values of long-term-stored nutrition in pig diets. In Exp. 1, 18 Landrace × Yorkshire (L × Y) barrows with an initial body weight (IBW) of 25.48 ± 3.21 kg were randomly assigned to three treatments, including a corn-based diet, one-year-stored brown rice (BR1) diet, and six-year-stored brown rice (BR6) diet, to determine the digestible energy (DE) and metabolizable energy (ME) values of stored brown rice. In Exp. 2, 24 barrows (L × Y; IBW: 22.16 ± 2.42 kg) fixed with ileal T-cannula were randomly allotted to four dietary treatments, including a corn diet, two stored brown rice diets, and a nitrogen-free diet, to evaluate the amino acid (AA) digestibility of the stored brown rice. In Exp. 3 and 4, 108 crossbred weaned piglets (L × Y; IBW: 9.16 ± 0.89 kg) and 90 crossbred growing pigs (L × Y; IBW: 48.28 ± 3.51 kg) were allotted to three treatment diets, including a control diet and two stored brown rice diets, respectively, to investigate the application of stored brown rice in weaned piglets and fully grown pig diets. The results indicated that there was no significant difference in the DE and ME values between corn and stored brown rice (p > 0.05), while the apparent ileal digestibility (AID) of arginine, histidine, asparagine + aspartic acid (Asx), and the standardized ileal digestibility (SID) of arginine and histidine were higher in the stored brown rice diet compared to the corn diet (p < 0.05). Compared to the corn, the stored brown rice showed no significant effects on growth performance, nutrient-apparent total tract digestibility (ATTD), and serum biochemical indices (p > 0.05) but showed decreased activity in the various digestive enzymes in the duodenum, jejunum, and ileum of the weaned piglets (p < 0.05). Also, the stored brown rice diet showed no significant effects on growth performance, carcass traits, meat quality, as well as the fatty acid profiles in the longissimus dorsi muscle of fully grown pigs compared with the corn diet (p > 0.05). In conclusion, the brown rice stored for 6 years under good conditions had no obvious changes in the available energy and nutrient values. Although it may reduce digestive enzyme activity in the small intestines of the piglets, the stored brown rice showed no obvious adverse effects on growth performance and meat quality and can be effectively used in pig diets.

Electrospun Fe3O4-chitosan/polyvinyl alcohol nanofibrous film for improved capture and elimination of foodborne pathogens.

This study developed a new "capture and killing" antibacterial approach for efficient elimination of foodborne pathogens. Fe3O4-Chitosan (CS)/polyvinyl alcohol (PVA) nanofibrous films with improved antibacterial and mechanical properties were fabricated by a simple, environmentally friendly, and cost-effective electrospinning technique. The relationship between the physical properties (viscosity, surface tension, and conductivity) and spinnability of CS/PVA as fiber forming matrix was explored. Electrospun Fe3O4-CS/PVA films (0.03-0.12 mm) with smooth and bead-free nanofibrous structures (145-169 nm) were successfully obtained. Compared with the film electrospun from neat CS/PVA, incorporating Fe3O4 nanoparticles (NPs) (1.25-5 wt%) in CS/PVA nanofibrous film promoted bacterial attachment and increased the final inactivated efficiency, showing a difference with Fe3O4 loading and bacterial strain, which had the highest value against Escherichia coli (E. coli) and Staphyloccus aureus (S. aureus) being 90 % and 66.30 %, respectively. The tensile strength and elongation at break of Fe3O4-CS/PVA films enhanced by 46-192 % and 92-141 %, respectively. Results of the cytotoxicity test indicated that the resulting films had high biocompatibility. These promising findings provide a novel strategy for effective foodborne pathogens elimination, which could apply to sterilizing and food packaging to extend the shelf life of liquid food.

Effects of Solid-State Fermented Wheat Bran on Growth Performance, Immune Function, Intestinal Morphology and Microflora in Lipopolysaccharide-Challenged Broiler Chickens.

The study evaluated the effects of dry and wet solid-state fermented wheat bran (FWB) on growth performance, immune function, intestinal morphology and microflora in lipopolysaccharide (LPS)-challenged broiler chickens. The experiment was designed as a 2 × 3 factorial arrangement. A total of 252 one-day-old Arbor Acres male broiler chickens were randomly allocated to 1 of 6 treatments: basal diet + sterile saline (negative control, NC), basal diet + LPS (positive control, PC), 7% dry FWB + sterile saline (FWB-I), 7% dry FWB + LPS (FWB-II), 7% wet FWB + sterile saline (FWB-III) and 7% wet FWB + LPS (FWB-IV), with containing 6 replicate cages/treatment and 7 broiler chickens/cage, and the experimental period lasted for 42 days. Broilers were intraperitoneally injected with either 0.5 mg LPS or sterile saline solution per kg body weight at 16, 18 and 20 d of age. Growth performance, serum immunological parameters and indicators related to intestinal health were analyzed on days 21 and 42. Compared with NC, dry and wet FWB significantly increased (p < 0.05) average daily feed intake of days 21 to 42, and increased (p < 0.05) the villus height and villus height to crypt depth ratio of ileum on day 21, decreased (p = 0.101) the jejunum crypt depth and decreased (p < 0.05) the Lactobacillus and Bifidobacterium counts of the cecum digesta on day 42. Compared with NC, FWB-II and FWB-IV significantly increased (p < 0.05) the levels of serum total protein and globulin on day 21; compared with the basal diet groups, dry and wet FWB groups significantly increased (p < 0.05) glucose levels on day 21, and wet FWB significantly decreased (p < 0.05) alanine aminotransferase levels on day 42. Compared with PC and FWB-II, FWB-IV significantly increased (p < 0.05) the level of serum immunoglobulin G on day 21. Compared with PC and FWB-II, FWB-IV significantly decreased (p < 0.05) the levels of serum pro-inflammatory cytokines interleukin (IL)-6, IL-8, IL-1ß and acute C reactive protein (CRP) on day 21; compared with FWB-III, FWB-IV significantly decreased (p < 0.05) the levels of IL-6, IL-8, CRP and tumor necrosis factor alpha on day 42, but the levels of IL-4 and IL-10 were significantly increased (p < 0.05) on days 21 and 42. These results indicated that supplementing 7% dry or wet FWB can improve growth performance and serum immune functions of broilers, which effectively alleviate the LPS-challenged damage, and wet FWB had a better effect than dry FWB.

Effects of synbiotic on growth, digestibility, immune and antioxidant performance in broilers.

The overuse of in-feed antibiotics has been associated with serious issues, including the developing of antibiotic-resistant pathogens and causing drug residues in poultry products. To date, many countries have restricted the use of growth-promoting antibiotics in food animals, resulting in the increased need for effective alternatives to in-feed antibiotic. Synbiotics, which are composed of probiotics and prebiotics, have been shown to act synergistically when applied simultaneously. Thus, this study investigated the effects of a synbiotic, composed of microencapsulated Lactobacillus plantarum (MLP) and fructooligosaccharide (FOS), on growth, immune and antioxidant parameters, and digestibility of calcium and phosphorus in broilers. A total of 168 newly hatched male broilers were randomly allotted to three dietary groups (n = 7): (1) a corn-soybean meal basal diet (CON); (2) basal diet + synbiotic (SYN); and (3) basal diet + aureomycin (ANT). Compared with the CON, chickens had greater average daily gain and digestibility of calcium and phosphorus in the SYN group (P < 0.05). In the SYN and ANT group, serum IgA, IgG, and IL-10 levels were higher, while the serum TNF-α, IL-2, and IL-6 levels were reduced (P < 0.05) compared to CON. Compared with CON, the level of serum malondialdehyde was lower (P < 0.05) and SOD level was higher (P < 0.05) in either SYN or ANT group. No significant differences in populations of Escherichia coli were seen in chickens among the three groups, whereas, the populations of Lactobacillus were higher (P < 0.05) in chickens in the SYN group compared with those in CON and ANT groups. Taken together, the addition of SYN, consisting of MLP and FOS, had benefits on growth, immune and antioxidant parameters, and digestibility of calcium and phosphorus, indicating its potential to serve as a substitute for antibiotics in broiler feeding.

Effect of Environmental Conditions on Synnema Formation and Nucleoside Production in Cicada Flower, Isaria cicadae (Ascomycetes).

Isaria cicadae (syn. Cordyceps cicadae) is one of the most valued edible and medicinal fungi and has been used in Asia as a substitute for Ophiocordyceps sinensis. Wild I. cicadae is limited and seasonal, and its cultivation is deserved. In this investigation we studied synnema formation by and nucleoside production in cicada flower under different environmental conditions. I. cicadae produced an asexual structure and mitospores instead of meiotic ascospores; this indicates that the term "synnema" is more suitable than "fruiting body" for this species. The optimal temperature was 25°C for growth of I. cicadae mycelia on potato dextrose agar plates but was 20°C for synnema formation on wheat medium. Synnemata can grow well under blue, green, and white light, and the dry weight of samples grown under these 3 light wavelengths is not significantly different. However, neither primordia nor synnemata formed under red light. Blue light promotes conidia production and white light promotes N6-(2-hydroxyethyl)-adenosine (HEA) production. Weak white light at 50 and 150 lux was more suitable for synnema production than strong-intensity light at 850 lux. The growth curve showed that HEA content has the same trend as synnema production over the entire cultivation period. The optimal harvesting time for I. cicadae cultivated on wheat medium is 35 days after inoculation. HEA content in the synnemata cultivated on wheat medium under the optimal conditions was significantly higher than that of the wild species and of synnemata cultivated on pupae, suggesting that synnemata cultivated on wheat medium may have potential as a substitute for wild resources. The results presented herein provide a new strategy for producing superior-quality synnemata of I. cicadae and further elucidate the effects of environmental conditions on metabolite accumulation in fungi.

Comparative Transcriptome Analysis Between a Spontaneous Albino Mutant and Its Sibling Strain of Cordyceps militaris in Response to Light Stress.

Albinism has been used for new variety screening in some edible mushrooms and the underlying mechanisms are fascinating. Albino fruiting body of Cordyceps militaris, a well-known edible fungus and model organism for Cordyceps, has the potential to be a nutraceutical or functional food due to its high content of metabolites and antioxidant activities. In this study, a spontaneous albino mutant strain (505) of C. militaris was obtained. In comparison to its normal sibling strain (498), the albino strain stably remained white in response to light and had significantly decreased conidia and carotenoid production but accumulated more cordycepin. Transcriptome analysis of both strains revealed that all the seven photoreceptors were expressed similarly in response to light. However, many more genes in the albino strain were differentially expressed in response to light than its sibling strain. The significantly enriched pathways in 498L vs. 505L were mainly associated with replication and repair. Some secondary metabolite backbone genes including those encoding DMAT, two NRPS-like proteins, three NPRS, and lanosterol synthase were differentially expressed in the albino when compared with that of the normal strains. Transcriptome and real-time quantitative PCR analyses indicated that some cytochrome P450s and methyltransferases might be related to the phenotypic differences observed between the two strains. This study compared the genome-wide transcriptional responses to light irradiation in a spontaneous albino mutant and its normal sibling strain of an edible fungus, and these findings potentially pave the way for further investigation of the pigment biosynthetic pathway.

Influence of Strain Preservation Methods on Fruiting Body Growth and Metabolite Production by the Medicinal Mushroom Cordyceps militaris (Ascomycetes).

Cordyceps militaris is a highly valued edible and medicinal fungus because of its production of various metabolites including adenosine, cordycepin, and N6-(2-hydroxyethyl)-adenosine. Fruiting bodies of this fungus have been used successfully in industrial production and widely as a substitute for Ophiocordyceps sinensis (syn. C. sinensis) in traditional Chinese medicine and health supplements. Strain degeneration occurs with high frequency during the subculturing and preservation of C. militaris strains, which leads to significant losses during industrial production. In this study, we evaluated the effects of different strain preservation methods on fruiting body growth and metabolite production. We found that strain degeneration affects not only fruiting body differentiation but also metabolite production, and suitable preservation methods can avoid degeneration. Preservation in sterile water has a similar effect as cryopreservation in liquid nitrogen at -196°C with regard to maintaining the characteristics of C. militaris strains for at least 1 year, and it is a practical and satisfactory method for preserving C. militaris strains that can be used in factories. Ultracold freezing at -80°C is not suitable for this fungus. Lyophilization, which causes C. militaris strains to retain their inherent characteristics and avoid degeneration, is suitable for long-term preservation (at least 4 years). This study provides practical preservation methods for C. militaris strains over the short and long term and will be helpful to achieve stable and superior-quality production of C. militaris fruiting bodies.

Beauveria bassiana: a new N6-(2-hydroxyethyl)-adenosine-producing fungus.

N6-(2-Hydroxyethyl)-adenosine (HEA), which was the first calcium antagonist derived from biological sources, has been intensively investigated because of its ability to inhibit tumour cell proliferation, restrain inflammation, protect kidneys and function as a sedative and insecticide. Up to now, the production of HEA has been detected only in a few species such as Cordyceps pruinosa, C. militaris and Isaria tenuipes. Here, we found a new HEA-producing fungus, which was identified as Beauveria bassiana based on morphological and phylogenetic characteristics. The HEA production was verified by reversed-phase high-performance liquid chromatography/mass spectrometry in this fungus. Moreover, HEA was also detected in the mycelia of two other B. bassiana strains from different origins, but not in the culture medium of all tested B. bassiana strains. The maximum production of HEA (0.8483 ± 0.0439 mg/g mycelia dry weight) was achieved on day 7. The fungal biomass and kinetics of HEA production exhibited similar trends over the duration of the culture period. This is the first report describing HEA production in B. bassiana, which suggests that this fungal strain may have new applications as a source of HEA.