Pseudomonas laoshanensis sp. nov., isolated from peanut field soil.

A novel Gram-stain-negative, aerobic strain, designated Y22T, was isolated from peanut field soil in Laoshan Mountain in China. Cells of strain Y22T were rod-shaped and motile by a single flagellum. The strain was found to be oxidase- and catalase-positive. 16S rRNA gene sequence based on phylogenetic analysis indicated that strain Y22T belonged to the genus Pseudomonas, and showed the highest 16S rRNA gene sequence similarity of 99.0% to Pseudomonas pelagia JCM 15562T, followed by Pseudomonas salina JCM 19469T (98.4%), Pseudomonas sabulinigri JCM 14963T (97.9%), Pseudomonas bauzanensis CGMCC 1.9095T (97.6%) and Pseudomonas litoralis KCTC23093T (97.5%). The phylogenetic analysis based on multilocus sequence analyses with concatenated 16S rRNA, gyrB, rpoD and rpoB genes indicated that strain Y22T belonged to Pseudomonas pertucinogena lineage. The average nucleotide identity scores between strain Y22T and closely related species were 74.6-82.8%, and the Genome-to-Genome Distance Calculator scores were 16.4-44.9%. The predominant cellular fatty acids of strain Y22T were C18:1ω7c (29.6%), C17:0 cyclo (17.5%) and summed feature 3 (C16:1ω7c and/or C16:1ω6c) (17.4%). The genomic DNA G+C content was 57.9 mol%. On the basis of phenotypic characteristics, phylogenetic analyses and in silico DNA-DNA relatedness, a novel species, Pseudomonas laoshanensis sp. nov. is proposed. The type strain is Y22T (= JCM 32580T = KCTC 62385T = CGMCC 1.16552T).

Pseudomonas qingdaonensis sp. nov., an aflatoxin-degrading bacterium, isolated from peanut rhizospheric soil.

A Gram-stain-negative, aerobic, mobile, and rod-shaped bacterium, designated JJ3T, was isolated from peanut rhizospheric soil in Qingdao, Shandong Province, China, and was characterized using a polyphasic approach. Strain JJ3T grew at 4-40 °C, at pH 5.0-9.0 and 0-4% NaCl. The strain was positive for both catalase and oxidase tests, and was able to degrade aflatoxin B1. According to the 16S rRNA gene sequence comparisons, the strain JJ3T was identified as a member of the genus Pseudomonas and was most closely related to Pseudomonas japonica JCM 21532T and Pseudomonas alkylphenolica JCM 16553T with sequence similarity of 99.0% and 98.9%, respectively. A multilocus sequence analysis (MLSA) of concatenating 16S rRNA, gyrB and rpoD gene sequences showed that strain JJ3T belonged to the Pseudomonas putida subcluster. Genomic comparison of strain JJ3T with its closest phylogenetic type strain using average nucleotide index (ANI) and digital DNA-DNA relatedness revealed 76.7-82.9% and 20.2-37.1%, respectively. All values were distinctly lower than the thresholds established for species differentiation. The predominant cellular fatty acids of strain JJ3T were C17:0 cyclo (24.0%), C16:0 (21.4%), summed features 3 (C16:1ω7c and/or C16:1ω6c) (11.5%) and summed features 8 (C18:1ω7c and/or C18:1ω6c) (10.5%). The major polar lipids of strain JJ3T were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The physiological, biochemical, and genetic characteristics support the assignment of JJ3T to the genus Pseudomonas, but are different to those of phylogenetically neighboring species to represent a novel species. The name Pseudomonas qingdaonensis sp. nov. is proposed, with JJ3T (= JCM 32579T = KCTC 62384T = CGMCC 1.16493T) as the type strain.

Evaluation of physicochemical and antioxidant properties of peanut protein hydrolysate.

Peanut protein and its hydrolysate were compared with a view to their use as food additives. The effects of pH, temperature and protein concentration on some of their key physicochemical properties were investigated. Compared with peanut protein, peanut peptides exhibited a significantly higher solubility and significantly lower turbidity at pH values 2-12 and temperature between 30 and 80°C. Peanut peptide showed better emulsifying capacity, foam capacity and foam stability, but had lower water holding and fat adsorption capacities over a wide range of protein concentrations (2-5 g/100 ml) than peanut protein isolate. In addition, peanut peptide exhibited in vitro antioxidant properties measured in terms of reducing power, scavenging of hydroxyl radical, and scavenging of DPPH radical. These results suggest that peanut peptide appeared to have better functional and antioxidant properties and hence has a good potential as a food additive.

Chemical composition and antioxidant activities of Broussonetia papyrifera fruits.

Fruits of Broussonetia papyrifera from South China were analyzed for their total chemical composition, and antioxidant activities in ethanol and aqueous extracts. In the fruit of this plant, the crude protein, crude fat and carbohydrates was 7.08%, 3.72% and 64.73% of dry weight, respectively. The crude protein, crude fat and carbohydrates were 15.71%, 20.51% and 36.09% of dry weight, respectively. Fatty acid and amino acid composition of the fruit were analyzed. Unsaturated fatty acid concentration was 70.6% of the total fatty acids. The percentage of the essential amino acids (EAAs) was 40.60% of the total amino acids. Furthermore, B. papyrifera fruit are rich in many mineral elements and vitamins. Total phenolic content was assessed using the Folin-Ciocalteau assay, whereas antioxidant activities were assessed by measuring the ability of the two extracts to scavenge DPPH radicals, inhibit peroxidation, and chelate ferric ions. Their reducing power was also assessed. Results indicated that the aqueous extract of B. papyrifera was a more potent reducing agent and radical-scavenger than the ethanol extract. GC-MS analysis of the ethanol extract showed the presence of some acid-containing compounds. The changes in total phenolic content and antioxidant capacity in B. papyrifera from four different regions grown under normal conditions were assessed. The antioxidant activity of different extracts was positively associated with their total phenolic content. These results suggest that the fruit of B. papyrifera could be used in dietary supplement preparations, or as a food additive, for nutritional gain, or to prevent oxidation in food products.