Effects of Caulerpa taxifolia on Physiological Processes and Gene Expression of Acropora hyacinthus during Thermal Stress.

An increasing ecological phase shift from coral-dominated reefs to macroalgae-dominated reefs as a result of anthropogenic impacts, such as eutrophication, sedimentation, and overfishing, has been observed in many reef systems around the world. Ocean warming is a universal threat to both corals and macroalgae, which may alter the outcome of competition between them. Therefore, in order to explore the effects of indirect and direct exposure to macroalgae on the physiological, biochemical, and genetic expression of corals at elevated temperature, the coral Acropora hyacinthus and highly invasive green algae Caulerpa taxifolia were chosen. Physiologically, the results exhibited that, between the control and direct contact treatments, the density and chlorophyll a content of zooxanthella decreased by 53.1% and 71.2%, respectively, when the coral indirectly contacted with the algae at an ambient temperature (27 °C). Moreover, the enzyme activities of superoxide dismutase (SOD) and catalase (CAT) in coral tissue were enhanced by interacting with algae. After an increase of 3 °C, the density and chlorophyll a content of the zooxanthella reduced by 84.4% and 93.8%, respectively, whereas the enzyme activities of SOD and CAT increased 2.3- and 3.1-fold. However, only the zooxanthellae density and pigment content decreased when Caulerpa taxifolia was co-cultured with Acropora hyacinthus at 30 °C. Molecularly, different from the control group, the differentially expressed genes (DEGs) such as Rab family, ATG family, and Casp7 genes were significantly enriched in the endocytosis, autophagy, and apoptosis pathways, regardless of whether Acropora hyacinthus was directly or indirectly exposed to Caulerpa taxifolia at 27 °C. Under thermal stress without algae interaction, the DEGs were significantly enriched in the microbial immune signal transduction pathways, such as the Toll-like receptor signaling pathway and TNF signaling pathway, while multiple cellular immunity (IFI47, TRAF family) and oxidative stress (CAT, SODC, HSP70) genes were upregulated. Inversely, compared with corals without interaction with algae at 30 °C, the DEGs of the corals that interacted with Caulerpa taxifolia at 30 °C were remarkably enriched in apoptosis and the NOD-like receptor signaling pathway, including the transcription factors such as the Casp family and TRAF family. In conclusion, the density and chlorophyll a content of zooxanthella maintained a fading tendency induced by the macroalgae at ambient temperatures. The oxidative stress and immune response levels of the coral was elevated at 30 °C, but the macroalgae alleviated the negative effects triggered by thermal stress.

[Interaction Between Sulfonamide Antibiotics Fates and Chicken Manure Composting].

Based on aerobic manure composting with or without the addition of a mixture of sulfadimethoxine SM2 and sulfamonomethoxine SMM (1:1, m/m), changes in the physic-chemical properties of manure compost, the microbial community physiological profiles, the antibiotics concentration and the abundances of five antibiotic resistance genes (ARGs) during the composting were tracked. The results indicated that the introduction of sulfonamide antibiotics led to inhibition on the basal respiration of manure compost during the early composting period, delayed the formation of thermophilic temperature and reduced the conversion of nutrients such as organic matter, ammonia nitrogen and nitrate nitrogen. Meanwhile, the introduction of sulfonamide antibiotics dramatically affected the physiological profile of microbial community in manure in the middle stage of composting. HPLC-MS/MS results showed that both SMM and SM2 in manure were completely degraded within 14 days, while the degradation rate of SMM was faster than that of SM2. For both composting treatments with or without addition of exogenous antibiotics, the relative abundance of sull and sul2 showed an initial decline in the first 14 or 21 days and a slight increase thereafter. The addition of exogenous antibiotics showed insignificant enhancement on increasing the relative abundance of sul1 and IntI1 in manure, but resulted in an apparent increase in sul2 relative abundance. Although the fates of tetQ and tetW during composting were different from that of sulfonamide ARGs, the introduction of sulfonamide antibiotics into manure increased the relative abundance of tetracycline ARGs. Redundancy analysis indicated that composting temperature correlated negatively with sul1, sul2 and IntI1 relative abundance in manure but had no obvious relationship with tetQ and tetW relative abundance. All the ARGs detected in this work correlated negatively with C/N ratio and the nitrate nitrogen concentration of manure compost but positively correlated with pH, moisture and ammonia nitrogen concentration of manure compost.

[Distribution characteristics of aggregates organic carbon in a paddy soil chronosequence].

By the method of physical fractionation of organic matter, this paper studied the distribution characteristics of organic carbon in different particle size aggregates in a paddy soil chronosequence on the south bank of Hangzhou Bay, East China. In the plow layers of the paddy soil chronosequence, micro-aggregates (<0. 25 mm) dominated, and the proportion of large micro-aggregates (0.053-0.25 mm) decreased with increasing rice cultivation year. In the micro-aggregates (<0. 053 mm and 0. 053-0. 25 mm), the organic carbon content increased with increasing rice cultivation time; and in the aggregates (0. 053-2 mm), the ratio of the organic carbon in different particle size fractions to the bulk soil organic carbon increased with decreasing particle size, and the organic carbon mainly distributed in large micro-aggregates (0. 053 -0. 25 mm). With increasing rice cultivation time, soil particulate organic carbon decreased, indicating that the paddy soil with a longer rice cultivation history had a stronger capability of carbon sequestration than the soil with a shorter rice cultivation history, and the early cultivated paddy soil still had great potential for carbon sequestration.

Taxonomic position of Eothenomys wardi (Arvicolinae: Cricetidae) based on morphological and molecular analyses with a detailed description of the species.

Ward's Red-backed Vole (Eothenomys wardi) is a rodent from the family Cricetidae. This endemic species occurs only in extreme northwestern Yunnan province, China in the Mekong and Salween river divide. It occupies steep cliffs at 2,800 to 4,250 m above sea level on the remote Qinghai-Tibetan plateau. The validity of E. wardi is controversial and no specimens exist apart from the nominal series. In 2010, we collected 38 topotypes of E. wardi from Meri Snow Mountain. The results of our phylogenetic analyses based on nucleotide sequences of the mitochondrial genes cytochrome b (cytb) and cytochrome c oxidase subunit one (COI) suggest that E. wardi is the sister group of E. custos, against its previously presumed sister species or conspecific species E. chinensis. In addition, seven out of 34 morphological characters differentiate E. wardi from other members of the genus Eothenomys. Therefore, we consider E. wardi to be a valid species and we provide its detailed morphological description.

[Effect of DMPP on inorganic nitrogen runoff loss from vegetable soil].

The effect of urea with 1% 3,4-dimethyl pyrazole phosphate (DMPP) on inorganic nitrogen runoff loss from agriculture field was determined in an undisturbed vegetable soil by using the simulated artificial rainfall method. The results show that, during the three simulated artificial rainfall period, the ammonium nitrogen content in the runoff water is increased 1.42, 2.82 and 1.95 times with the DMPP application treatment compared to regular urea treatment, respectively. In the urea with DMPP addition treatment, the nitrate nitrogen content is decreased 70.2%, 59.7% and 52.1% in the three simulated artificial rainfall runoff water, respectively. The nitrite nitrogen content is also decreased 98.7%, 90.6% and 85.6% in the three simulated artificial rainfall runoff water, respectively. The nitrate nitrogen and nitrite nitrogen runoff loss are greatly declined with the DMPP addition in the urea. Especially the nitrite nitrogen is in a significant low level and is near to the treatment with no fertilizer application. The inorganic nitrogen runoff loss is declined by 39.0% to 44.8% in the urea with DMPP addition treatment. So DMPP could be used as an effective nitrification inhibitor to control the soil ammonium oxidation, decline the nitrogen runoff loss, lower the nitrogen transformation risk to the waterbody and be beneficial for the ecological environment.

[Study on the drug-resistant genes associated with beta-lactams and aminoglycosides in clinically isolated Pseudomonas aeruginosa].

OBJECTIVE: To investigate drug-resistant genes associated with beta-lactams and aminoglycosides in clinically isolated Pseudomonas aeruginosa. METHODS: Twenty strains of Pseudomonas aeruginosa were isolated from wound excretion of hospitalized burn patients. The strains resistant to 14 antibiotics were selected for detection of 16 kind of drug-resistant genes (TEM, SHV, OXA-10 cluster, PER, VEB, GES, CARB, CTX-M- I, IMP, VIM, SPM, GIM, DHA, MOX, FOX, oprD2) and 6 kind of aminoglycoside modification genes (aac(3)- I, aac(3)-II, aac(6')-I, aac(6')-II, ant (3")- I , ant(2")- I) in them by PCR. RESULTS: Among the 20 strains resistant to beta-lactam , all of them were TEM and GES positive (100%), oprD2 gene depletion in 5 strains (25%). All other genes were negative. Among aminoglycoside resistant genes, 20 strains were aac (6') - I positive (100%), 7 were ant (2") - I positive (35%), and negative for other stains. CONCLUSION: There were very high existence rates of TEM, GES and aac (6')- I genes in Pseudomonas aeruginosa isolated from clinical burn patients. The fact that GES-5 gene has also been detected in Pseudomonas aeruginosa, suggesting this organism is highly drug resistant in our burn unit.