Fusarium wilt of watermelon, caused by F. oxysporum f.sp. niveum (FON), is a devastating disease that causes extensive losses throughout the world. Five bacterial strains (L3, h, β, b, and L) isolated from the watermelon rhizosphere showed antagonistic activity against FON during in vitro tests. Strain L3 produced diffusible and volatile organic compounds (VOCs) which showed the strongest antifungal activity. Arabidopsis thaliana plantlets exposed to VOCs produced by strain L3 showed a 2.39‐fold increase in biomass, 1.40‐fold increase in primary root length, and 5.05‐fold increase in number of lateral roots. Confocal laser scanning microscope showed that the GFP‐labeled strain L3 could colonize along the elongation and differentiation zones of watermelon roots. In greenhouse pot experiments, the biocontrol efficiency of strain L3 against fusarium wilt of watermelon was up to 68.4% in comparison with the control treatment. In addition, inoculation of the strain L3 resulted in a 23.4% increase in plant fresh weight. Based on 16S rDNA sequence analysis, the strain L3 was identified as Bacillus amyloliquefaciens L3. Fourteen VOCs produced by strain L3 were identified through GC‐MS analysis. Of nine VOCs tested, 2‐nonanone and 2‐heptanone were proved to have strong antifungal properties. Acetoin and 2,3‐butanediol were found to promote plant growth. The results suggested B. amyloliquefaciens L3 was a potential biocontrol agent, and that VOCs produced by B. amyloliquefaciens L3 play important roles in the process of biocontrol and plant growth promotion.

BackgroundA keloid is a fibroproliferative disorder occurring in wounds characterized by an exaggerated response to injury. To date, no effective cure has been identified. As multipotent stem cells, human adipose-derived stem cells (ADSCs) may show the possibility for curing diseases such as fibrosis. This study sought to explore the potential role of human ADSCs in curing keloids.MethodsAfter culture in conditioned medium, gene and protein expression of keloid fibroblasts was examined using real-time polymerase chain reaction (RT-PCR) and Western blotting, while analysis of the cell cycle was used to measure the proliferative properties of the cells. Furthermore, ex vivo explant cultures were used to test the effects of ADSC-conditioned medium (ADSC-CM) on CD31+ and CD34+ expression in keloid tissue.ResultsOur experimental results show that ADSC-CM was able to attenuate extracellular matrix-related gene expression as well as decrease protein expression. Cell proliferation was significantly suppressed in our study. CD31+ and CD34+ vessels in ex vivo explants were reduced by 55% and 57% in treatment groups compared with control groups.ConclusionsHuman ADSC-CM significantly inhibited keloid fibroblast-related bioactivities.

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Soil biofumigation with brassica plant residues has been shown to significantly suppress soilborne pathogen. However, little published data reported the impact of biofumigation on microbial community structure in pepper (Capsicum annuum L.) production systems under field conditions. Biofumigation with rapeseed (Brassica napus 'Dwarf Essex') meal and chemical fumigation with dazomet were tested to control the pepper disease caused by Phytophthora capsici. BF treatment showed the lowest disease incidence among these treatments. Effects on soil bacterial and fungal communities were assessed by denaturating gradient gel electrophoresis and the results showed that the biofumigation increased bacterial diversity and decreased fungal diversity. There was a negative correlation between soil bacterial diversity and disease incidence and a positive correlation between soil fungal diversity and disease incidence. Cloning of the microbial community showed that the microbial community structures were altered by biofumigation. Soil was also evaluated for their chemical properties. Biofumigation increased soil content of total N, NO3(-)-N, available P and available K. A significant correlation between soil microbial community structures and soil chemical properties was found. Overall, these results indicated that biofumigation reduced disease incidence of pepper through altering soil microbial community structures.

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This experiment was conducted to investigate the effect of exposure to high altitude and low oxygen on intestinal microbial communities using mice as an animal model. Fecal microbiota from mice housed in a control environment representing 2,200 meters (NC group) above sea level with 16% Oxygen and mice that were placed in a hypobaric chamber representing 5000 meters (HC group) above sea level with 11% Oxygen for 30 days, were analyzed by the HiSeq Illumina sequencing platform. The results showed a significant difference in beta diversity observed between the two groups, while no significant difference was observed in alpha diversity. Compared with the NC group, the relative abundance of class Epsilonproteobacteria, phlym Actinobacteria, class Erysipelotrichia and genus Helicobacter were significantly lower (P<0.05), while the relative abundance of genus Alistipes was increased in the HC group; Phenotypic analysis showed no significant difference in aerobic, anaerobic, facultatively anaerobic, potentially pathogenic, stress tolerant, mobile element, biofilms formation, gram negative and gram positive between HC group and NC group; Functional analysis results showed significant differences in 34 gene functional metabolic pathways (carbohydrate digestion and absorption, energy metabolism, arachidonic acid metabolism, flavonoid biosynthesis, RIG-I-like receptor signaling pathway, etc) between HC group and NC group. Together, these findings suggest that exposure to high altitude and low oxygen had the potential to change the intestinal microbial communities, which potentially may modulate metabolic processes in mice.

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