Urease-producing bacteria combined with pig manure biochar immobilize Cd and inhibit the absorption of Cd in lettuce (Lactuca sativa L.).

The synergistic remediation of heavy metal-contaminated soil by functional strains and biochar has been widely studied. However, the mechanisms by which urease-producing bacteria combine with pig manure biochar (PMB) to immobilize Cd and inhibit Cd absorption in vegetables are still unclear. In our study, the effects and mechanisms of PMB combined with the urease-producing bacterium TJ6 (TJ6 + PMB) on Cd adsorption were explored. The effects of TJ6 + PMB on the Cd content and pH of the leachate were also studied through a 56-day soil leaching experiment. Moreover, the effects of the complexes on Cd absorption and microbial mechanisms in lettuce were explored through pot experiments. The results showed that PMB provided strain TJ6 with a greater ability to adsorb Cd, inducing the generation of CdS and CdCO3, and thereby reducing the Cd content (71.1%) and increasing the pH and urease activity in the culture medium. TJ6 + PMB improved lettuce dry weight and reduced Cd absorption. These positive effects were likely due to (1) TJ6 + PMB increased the organic matter and NH4+ contents, (2) TJ6 + PMB transformed available Cd into residual Cd and decreased the Cd content in the leachate, and (3) TJ6 + PMB altered the structure of the rhizosphere bacterial and fungal communities in lettuce, increasing the relative abundances of Stachybotrys, Agrocybe, Gaiellales, and Gemmatimonas. These genera can promote plant growth, decompose organic matter, and release phosphorus. Interestingly, the fungal communities were more sensitive to the addition of TJ6 and PMB, which play important roles in the decomposition of organic matter and immobilization of Cd. In conclusion, this study revealed the mechanism by which urease-producing bacteria combined with pig manure biochar immobilize Cd and provided a theoretical basis for safe pig manure return to Cd-polluted farmland. This study also provides technical approaches and bacterial resources for the remediation of heavy metal-contaminated soil.

5-HT1A receptor in the central amygdala and 5-HT2A receptor in the basolateral amygdala are involved in social hierarchy in male mice.

Most social animals self-organize into dominance hierarchies that strongly influence their behavior and health. The serotonin (5-HT) system is believed to play an important role in the formation of social hierarchy. 5-HT receptors are abundantly expressed in the amygdala, which is considered as the central node for the perception and learning of social hierarchy. In this study, we assessed the functions of various 5-HT receptor subtypes related to social rank determination in different subregions of the amygdala using the confrontation tube test in mice. We revealed that most adult C57BL/6 J male mice exhibited a linear social rank after a few days of cohousing. The tube test ranks were slightly related to anxiety-like behavioral performance. After the tube test, the amygdala and 5-HT neurons in the dorsal raphe nucleus were activated in lower-rank individuals. Quantitative real-time polymerase chain reaction analysis revealed that despite the high expression of 5-HT1A receptor mRNA in the central amygdala (CeA), 5-HT2A receptor mRNA expression was downregulated in the basolateral amygdala (BLA) in higher-rank individuals. The dominant-subordinate relationship between mouse pairs could be switched via pharmacological modulation of these receptors in CeA and BLA, suggesting that these expression changes are essential for establishing social ranks. Our findings provide novel insights into the divergent functions of 5-HT receptors in the amygdala related to social hierarchy, which is closely related to our health and welfare.

Molecular epidemiology, drug resistance, and virulence gene analysis of Streptococcus agalactiae isolates from dairy goats in backyard farms in China.

Streptococcus agalactiae infections may lead to clinical or subclinical mastitis in dairy animals when it invades the mammary gland. In this study, 51 S. agalactiae strains were isolated from 305 milk samples that were collected from goats with mastitis in 13 provinces of China. The antimicrobial resistance of S. agalactiae was determined by disk diffusion methods against 18 antibiotics from six classes. In addition, multilocus sequence typing (MLST), and the presence of resistance and virulence genes was determined by PCR analysis. Seven sequence types in five clonal complexes were identified according to MLST; CC103 and CC67 strains were predominant, with rates of 45.1% and 39.2%, respectively. All isolates (100%) were multiresistant to three or more antimicrobial agents. S. agalactiae isolates had a 100% resistance rate to penicillin, oxacillin, and amoxicillin, followed by doxycycline (82.4%), tetracycline (76.5%), and amikacin (74.5%). The lowest resistance was observed for ciprofloxacin (29.4%), which varied in five different regions. The detection rates of six classes of antimicrobial-related genes were calculated as follows: 33 (64.7%) for ß-lactam-related resistance gene, 12 (23.5%) for tetracyclines, 11 (21.6%) for quinolone-related resistance genes, 10 (19.6%) for aminoglycosides, 7 (13.7%) for macrolides (ermA, ermB, and mefA), and 3 (5.9%) for lincosamide (lnu(B)). Regarding virulence genes, profile 1 (bca cfb-cspA-cylE-hylB-bibA-pavA-fbsA-fbsB) was the most prevalent, with a detection rate of 54.9%. This work provides a primary source related to the molecular epidemiology of S. agalactiae in dairy goat herds in China and will aid in the clinical treatment, prevention, and control of mastitis.

Enhanced Cordycepin Production in Caterpillar Medicinal Mushroom, Cordyceps militaris (Ascomycetes), Mutated by a Multifunctional Plasma Mutagenesis System.

A multifunctional plasma mutation system (MPMS) method was used to create high cordycepin-yielding mutations from wild Cordyceps militaris, which yielded many viable mutants, many of which produced more cordycepin compared to the wild strain. One particular mutant strain (GYS60) produced 7.883 mg/mL, which is much higher than those reported to date and is more than 20 times higher than that of the wild strain, whereas the cordycepin production of another viable mutant (GYS80) was almost zero. The extraction and purification of cordycepin, using the fermentation broth of C. militaris GYS60, was also investigated. Cordycepin was extracted by using AB-8 macroporous resin and purified by using reversed-phase column chromatography. When the sample was adsorbed onto the macroporous resin, 20% ethanol was used as the desorption solvent yielding various fractions. The fractions containing cordycepin were loaded onto a reversed-phase chromatography column packed with octadecyl bonded silica as the stationary phase and ethanol (95%)/acetic acid solution (5%) at pH 6.0 as the mobile phase. The combination of this two-step extraction-purification process yielded cordycepin at 95% purity with a total recovery rate of 90%.

New Mutations of Penicillin-Binding Proteins in Streptococcus agalactiae Isolates from Cattle with Decreased Susceptibility to Penicillin.

Streptococcus agalactiae is a causal agent of bovine mastitis and is treated by ß-lactam antibiotics (BLAs). Compared to penicillin-resistant S. agalactiae from humans, resistant strains in bovine are rarely reported. In this study, we aimed to investigate BLA resistance and mutations in penicillin-binding proteins (PBPs) of S. agalactiae in central and northeast China. The minimum inhibitory concentrations (MICs) of 129 penicillin-resistant S. agalactiae isolates from cows with mastitis were determined, and the related PBP genes were detected and sequenced. All strains were unsusceptible to penicillin G and mostly resistant to ampicillin, cefalexin, and ceftiofur sodium. One hundred twenty-nine strains were divided into 4 clonal groups and 8 sequence types by multilocus sequence typing analysis. We found a set of new substitutions in PBP1B, PBP2B, and PBP2X from most strains isolated from three provinces. The strains with high PBP mutations showed a broader unsusceptible spectrum and higher MICs than those with few or single mutation. Our research indicates unpredicted mutations in the PBP genes of S. agalactiae isolated from cows with mastitis treated by BLAs. This screening is the first of S. agalactiae from cattle.

Spathaspora allomyrinae sp. nov., a d-xylose-fermenting yeast species isolated from a scarabeid beetle Allomyrina dichotoma.

During an investigation of yeasts associated with insects, three strains of a d-xylose-fermenting yeast species were isolated from the gut of the host beetles Allomyrina dichotoma (Coleoptera: Scarabeidae) collected on the Baotianman National Nature Reserve, Nanyan, Henan Province, China. These strains formed two elongated ascospores, which were tapered and curved at the ends in persistent asci. Sequence analyses of the D1/D2 domains of the large subunit (LSU) and small subunit (SSU) rRNA genes showed that these new strains represent a phylogenetically distinct species in the Spathaspora clade. This novel species differed from the closest species, Candida lyxosophila NRRL Y-17539T, by a 6.7 % sequence divergence (31 substitutions and 7 gaps) in the D1/D2 LSU rRNA gene and a 1.2 % divergence (17 substitutions, 4 gaps) in the SSU rRNA gene. The novel species can also be distinguished from C. lyxosophila NRRL Y-17539T in terms of the ability to assimilate myo-inositol and to grow in the presence of 0.1 % cycloheximide, as well as the inability to assimilate citrate. The name Spathaspora allomyrinae sp. nov. is proposed for this species. The type strain is NYNU 1495T ( = CICC 33057T = CBS 13924T). The MycoBank number is MB 815071.

Candida funiuensi sp. nov., a cellobiose-fermenting yeast species isolated from rotten wood.

Two strains of an asexual cellobiose-fermenting yeast species were isolated from rotten wood samples collected in Funiu Mountain Nature Reserve in Henan Province, central China. Molecular phylogenetic analysis that included the nearly complete small subunit (SSU), the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit (LSU) rDNA showed that these strains belonged to the Candida kruisii clade, with Candida kruisii and Candida cretensis as their closest phylogenetic neighbours. The nucleotide differences between the novel strains and the type strains of C. kruisii and C. cretensis were 30 and 36 substitutions, respectively, in the D1/D2 LSU rDNA, 40 and 44 substitutions, respectively, in the ITS region and 19 and 23 substitutions, respectively, in the SSU rDNA. The novel strains can also be distinguished from their closest described species, C. kruisii and C. cretensis, by a number of physiological characteristics, and represent a novel species of the genus Candida, for which the name Candida funiuensis sp. nov. is proposed. The type strain is NYNU 14625T ( = CICC 33050T = CBS 13911T). The Mycobank number is MB 811503.

Effects of the metals lead and zinc on the growth, development, and reproduction of Pardosa astrigera (Araneae: Lycosidae).

Metal pollution is a serious environmental problem worldwide, and severely threatens biological diversity and human health. In order to investigate the effects of metals on a potential indicator species of wolf spider, Pardosa astrigera (Araneae: Lycosidae), 3rd-instar spiderlings were exposed to metals by using sublethal concentrations of PbCl2 and ZnCl2 solutions as their drinking water. The total durations of development of P. astrigera from the 3rd to 6th instars were significantly longer than that of the control group, and females showed a sharp reduction in total egg number. Body weights were significantly decreased in the mature spiders exposed to PbCl2 solutions and ZnCl2 solutions of high concentration (100 mM). These results suggest that detoxifying strategies deployed by P. astrigera against metal intoxication incur the costs of delayed development, and reduced growth and reproduction.

[The applied research on neural network filtrated by rough-set in insect taxonomy].

This article provides demonstrations and calculations, using rough-set theory and method, of the math-morphological features (MMFs), such as form parameter, lobation and sphericity, etc. drawn from 28 species of insects of the Hemiptera, Lepidoptera and Coleoptera based on their images. The results are compared with statistical analysis made by Zhao Hanqing, and also with the traditional classifications through the pattern recognition of neural network on the basis of the rough-set disposal. The result of the experiments showed that when used in categorical taxonomy, the importance of MMF was ranked from high to low: (roundness-likelihood. eccentricity) > (hot-hole number, sphericity, circularity) > (lobation, form parameter). The results of pattern recognition by neural network were completely identical with those of traditional classifications. Accordingly, the conclusion was that this theory applied in insect taxonomy was more idealistic compared with statistical analysis method, and it had great significance when used with rough-set neural network.