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The simulated ammonia nitrogen wastewater was treated with spent mushroom compost (SMC) in a laboratory bioreactor (LBR), and shifts in microbial diversity in LBR were conducted by polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE). We found that the removal efficiencies of NH4+-N and COD reached 73.4% and 61.7%, respectively, and that simultaneous nitrification and denitrification (SND) was observed during the process of NH4+-N removal. In addition, we observed that there were no obvious changes in microbial diversity shifts, and that the predominant four isolates were identified as Flavobacterium johnsoniae, Sphinbacterium multivorum, Comamonas sp., and Rhizobium sp., which functioned together and played a critical role in treating simulated ammonia nitrogen wastewater in LBR. Overall, SMC could provide both carbon sources and indigenous functional microorganisms for nitrogen removal, indicating that SMC has potential for wastewater treatment.
Our study navigated investigated the metal adsorption ability of bacterial Bacillus cereus strain HM-5 isolated from manganese ore. The effects of pH, initial metal ions concentration, biomass dose, contact time, and temperature on biosorption were studied. The results showed that the biosorption capacity of the B. cereus strain HM-5 for the metallic ions reached up to 98.9% for Mn at 600 mg/L initial metal ion concentration. The biosorptoin was most affected by pH and incubation temperature. Optimal pH and temperature were 6 and 35ºC, respectively. Optimal contact time was 5 d for biosorption by B. cereus strain HM-5. The surface chemical functional groups of B. cereus biomass identified by Fourier transform infrared (FTIR) were hydroxyl, alkyl, amide, phosphoryl, and phosphoric acid groups, which may be involved in the biosorption of heavy metals. SEM micrographs indicated that B. cereus HM-5 cells were irregular and cracked with the appearance of wrinkles and many flocs on the surface after Mn stress. The results showed that the selected bacteria had good application prospect in manganese-contaminated soil remediation.
The ethyl acetate fractions of aqueous extracts from two submerged macrophytes Potamogeton malaianus and Potamogeton maackianus were analyzed by gas chromatograph-mass spectrometry (GC-MS). The allelopathic activities and joint effects of the main components in ethyl acetate fractions on Microcystis aeruginosa were also determined. The results indicated that primary compositions in the ethyl acetate fractions were fatty acids, phenolic acids and hydroxy fatty acids that possessed antialgal activities. The joint effect assay for palmitic acid, benzoic acid and lactic acid showed that the additional effects were observed in the mixed organic acid, namely, the inhibitory effects of mixture groups were stronger than that of each compound alone on the growth of M. aeruginosa.
Spinal cord injury (SCI) is traumatic central nervous system damage resulting in a motor and sensory dysfunction that usually causes a severe and permanent paralysis. Today, the treatment of SCI principally includes surgical treatment, pharmacological treatments and rehabilitation therapies, which target secondary events determining only some clinical improvements in patients. SCI is still a worldwide problem in the clinic and remains a big challenge for neuroscientists and neurologists throughout the world. Therefore, new therapies able to restore the function of the injured spinal cord are urgently needed for SCI patients. An interesting approach to overcome the growth inhibiting properties present in the injured spinal cord is to transplant cells with reparative and protective properties such as mesenchymal stem cells. In this context, human dental‑derived stem cells represent a promising new cell source for cell‑based therapies. It has been shown that dental‑derived stem cells isolated from dental pulp, named dental pulp stem cells or stem cells from human exfoliated deciduous teeth induce functional improvement after SCI in animal models. This review summarises the current state of the literature regarding the use of dental‑derived stem cells for spinal cord repair and regeneration and highlights the neuroprotective effects of these cells when administered after spinal cord injury.
In recent decades, considerable attention has been paid to the serious water pollution caused by the fastgrowing aquaculture industry. On the other side, water quality determines to a great extent the success or failure of an aquaculture operation. So highlighted is the need for sustainable development of aquaculture. In the present work, we established a recirculating aquaculture system (RAS) by vertical-flow constructed wetlands (CWs) for channel catfish (Ictalurus punctatus) culture, and assessed its effects on water quality improvement. The results indicated that the CWs applied in the RAS showed relatively higher removal efficiency for particulate matter (more than 55%) and lower, uneven removal efficiency for nutrients and organic matter (from -34.1% to 48.7%). Paired t-tests showed that only parameters of NH4 +-N, TN, COD, BOD5, TSS, and Chl-a were significantly (p<0.05) lowered after wetland treatment. Despite this, nutrients (but NH4 +-N, NO2--N, and NO3--N), organic matter, and suspended solids (including plankton) in the recirculating ponds were significantly lowered compared to the control, indicating a decline in trophic status. Multivariate analyses revealed strong relationships between zooplankton community structure and the measured environment in the culture ponds. Cyanobacterial blooms that occurred heavily in the control were strongly restrained in the recirculating ponds. This led to water quality that was suitable for fish culture. Hereby, conclusions could be reached that the recirlulating treatment by the CWs achieved its aim of sustaining or extending water quality improvement in the RAS.
Plants deploy different strategies to respond and adapt to various stresses. Given that stresses affect plant growth and activity, the responses and tolerance of crops to stresses must be improved through genetic engineering. Inducible promoters, which have vital roles in gene expression and function, are highly desired in biotechnology applications. Thus, novel inducible promoters must be isolated and identified for genetic engineering to improve crop stress responses and tolerance. OsRhoGAPs are involved in plant defense against diverse stresses. In this study, we identified OsRhoGAP2, which is preferentially expressed in rice inflorescences. We isolated the OsRhoGAP2 promoter and analyzed its functions in transgenic Arabidopsis. We fused the GUS reporter with six 5′ deletion fragments (gp1–gp6) of the OsRhoGAP2 promoter with different lengths. Through histochemical analysis, we detected GUS activity in the inflorescences of transgenic Arabidopsis containing gp1, gp3, gp4, and gp5 constructs but not in transgenic Arabidopsis containing gp2 and gp6 constructs. The GUS activity in transgenic plants containing gp1–gp6 constructs changed under different stress treatments. Bioinformatics analysis and experimental results revealed that the core fragment involved in the inflorescence-preferential expression of OsRhoGAP2 and stress responses may be located in the − 706 bp to + 1 bp, or the translated start site, of OsRhoGAP2. Results indicate that OsRhoGAP2 has a conserved role in stress tolerance and exhibits tissue-specific expression patterns in several plant species. This work provides novel insights into the appropriate promoter resources for plant genetic transformation and useful references for biotechnologists to improve stress tolerance in rice.
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