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In recent years, peanut yield and quality are more seriously affected by pod rot disease in China. However, managing this disease has proven challenging due to the wide host range of its pathogens. In this study, four soil samples were collected from fields with pod rot disease in Hebei Province, and 454 pyrosequencing was used to analyze the fungal communities structure within them. All 38 490 ITS high-quality sequences were grouped into 1203 operational taxonomic units, the fungal community diversity of four soil samples was evaluated and compared using Shannon index and Simpson index. The results showed that members of Ascomycota were dominant, followed by Basidiomycota. According to the BLAST results at the species level, Guehomyces had the highest abundance, accounting for about 7.27%, followed by Alternaria, Fusarium, and Davidiella. The relative abundance of Fusarium oxysporum isolated from rotting peanuts in soil with peanut rot was higher than that in the control, indicating that Fusarium oxysporum might be one of the main pathogenic fungus of peanut rot in this area. This study delved into the broader fungal community associated with peanut pod rot, providing a theoretical foundation for preventing and treating this disease in agriculture. [ABSTRACT FROM AUTHOR]

In order to evaluation the efficiency of SRAP markers on genetic diversity of Aspergillus flavus, we screened out 17 sets of primer pairs which could produce clear and reproducible SRAP bands from 150 SRAP primer pairs. The size of SRAP fragments ranged from 120 to 2100 bp. Primer pair Me10/Em9 produced the maximum number of polymorphic bands (12 bands), while Me8/Em13 produced the fewest number of polymorphic bands (only 1). Through analysis genetic diversity ability of different sets of primer pairs, the set of 12 primer pairs was selected for SRAP genetic marker of A. flavus. Cluster analysis was performed based on the genetic similarity coefficients, which ranged from 0.53 to 0.89. A dendrogram assembled using the unweighted pair-group method with arithmetic averages grouped A. flavus samples into 5 main clusters. The results suggested that SRAP marker is a useful molecular technology for the diversity of A. flavus from peanut soils in China. [ABSTRACT FROM AUTHOR]

Peanut pods are easily infected by aflatoxin-producing Aspergillus species from field soil. To assess the aflatoxin-producing Aspergillus sp. in different peanut field soils, 344 aflatoxin-producing Aspergillus strains were isolated from 600 soil samples of four agroecological zones in China (the Southeast coastal zone (SEC), the Yangtze River zone (YZR), the Yellow River zone (YR) and the Northeast zone (NE)). Nearly 94.2% (324/344) of strains were A. flavus and 5.8% (20/344) of strains were A. parasiticus. YZR had the highest population density of Aspergillus sp. and positive rate of aflatoxin production in isolated strains (1039.3 cfu.g-1, 80.7%), the second was SEC (191.5 cfu.g-1, 48.7%), the third was YR (26.5 cfu.g-1, 22.7%), and the last was NE (2.4 cfu.g-1, 6.6%). The highest risk of AFB1 contamination on peanut was in YZR which had the largest number of AFB1 producing isolates in 1g soil, followed by SEC and YR, and the lowest was NE. The potential risk of AFB1 contamination in peanuts can increase with increasing population density and a positive rate of aflatoxin-producing Aspergillus sp. in field soils, suggesting that reducing aflatoxigenic Aspergillus sp. in field soils could prevent AFB1 contamination in peanuts. [ABSTRACT FROM AUTHOR]

The adult edible beetle Holotrichia parallela Motschulsky (Coleoptera: Scarabaeoidea) represents a traditional food source in China. Based on nutritional analyses, adult H. parallela is high in protein (70%) and minerals and low in fat. H. parallela contained approximately 10% chitin; the corrected protein content was 66%. Oleic acid and linoleic acid were the most abundant fatty acids. Of the total amino acids in H. parallela, 47.4% were essential amino acids. The amino acid scores were 87 and 100, based on the corrected crude and net protein contents, respectively; threonine was the limiting amino acid. In vitro protein digestibility was 78%, and the protein digestibility-corrected amino acid score was 89 based on the net protein content. Adult H. parallela may be a potential source of proteins and minerals for humans and animals. [ABSTRACT FROM AUTHOR]

The objective of this work is to provide a theoretical basis for preparing peanut antioxidant hydrolysate in order to improve its antioxidant activities. Therefore, response surface methodology (RSM) based on the Box-Behnken design was used to optimize ultrasonic-assisted enzymolysis for the purpose of preparing peanut antioxidant hydrolysate. Results indicated that the DPPH free radical scavenging activity of peanut hydrolysate could reach 90.06% under the following optimum conditions: ultrasonic power of 150.0 w, reaction temperature of 62.0 °C, incubation time of 25.0 min, and initial pH value of 8.5. The DPPH free radical scavenging rate of peanut hydrolysate from ultrasonic-assisted enzymolysis improved comparing with that of peanut hydrolysate from protease hydrolysis alone. The peanut antioxidant hydrolysate was found to display eight improved kinds of antioxidant activities. In conclusion, the optimal ultrasonic-assisted enzymolysis technology conditions described in this paper, appear to be beneficial for preparing peanut antioxidant hydrolysate [ABSTRACT FROM AUTHOR]

The best enzyme to prepare peanut peptides, papain, coupled with microwave irradiation was selected from five common proteases according to the results of the yield of peanut peptides [nitrogen solution index (NSI) in trichloroacetic acid (TCA), TCA-NSI] and the degree of hydrolysis (DH). The main factors that influenced the microwavecoupled enzymatic digestion method were optimized by response surface analysis. The optimal conditions obtained were as follows: microwave extraction time, 9.5 min; power, 600 W; substrate concentration, 4%; enzymatic reaction temperature, 50°C; enzyme quantity, 6,500 U/g; pH, 7.1 (phosphate buffer, 0.05 mol/L). Under these conditions, TCA-NSI was 62.00% and DH was 25.89%, which is higher than that obtained with either protease hydrolysis or microwave hydrolysis alone. [ABSTRACT FROM AUTHOR]

Insect chitin was isolated from adult Holotrichia parallela by treatment with 1 M HCl and 1 M NaOH, following by 1% potassium permanganate solution for decolorization. The yield of chitin from this species is 15%. This insect chitin was compared with the commercial α-chitin from shrimp, by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and elemental analysis. Both chitins exhibited similar chemical structures and physicochemical properties. Adult H. parallela is thus a promising alternative source of chitin. [ABSTRACT FROM AUTHOR]