Selection of the Dominant Endophytes Based on Illumina Sequencing Analysis for Controlling Bacterial Wilt of Patchouli Caused by Ralstonia solanacearum.

Bacterial wilt caused by Ralstonia solanacearum (RS) is one of the most devastating diseases in patchouli (Pogostemon cablin [Blanco] Benth.), which results in low yield and quality of patchouli. However, no stable and effective control methods have been developed yet. To evaluate the potential of dominant bacterial endophytes in biocontrol, the endophytic bacterial diversity of patchouli was investigated based on Illumina sequencing analysis, and the ability of isolates belonging to the dominant bacterial genera to control RS wilt of patchouli was explored in pot experiments. A total of 245 bacterial genera were detected in patchouli plants, with the highest relative abundance of operational taxonomic units belonging to the genus Pseudomonas detected in roots, leaves, and stems. The Pseudomonas isolates S02, S09, and S26 showed antagonistic activity against RS in vitro and displayed many plant growth-promoting characteristics, including production of indole-3-acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylic acid deaminase and phosphate- and potassium-solubilizing capability. Inoculation of patchouli plants with the isolates S02, S09, and S26 significantly improved shoot growth and decreased the incidence of bacterial wilt caused by RS. The results suggest that screening of dominant bacterial endophytes for effective biocontrol agents based on Illumina sequencing analysis is more efficient than random isolation and screening procedures.

Engineering functional materials through bacteria-assisted living grafting.

Functionalizing materials with biomacromolecules such as enzymes has broad applications in biotechnology and biomedicine. Here, we introduce a grafting method mediated by living cells to functionalize materials. We use polymeric scaffolds to trap engineered bacteria and micron-sized particles with chemical groups serving as active sites for grafting. The bacteria synthesize the desired protein for grafting and autonomously lyse to release it. The released functional moieties are locally grafted onto the active sites, generating the materials engineered by living grafting (MELGs). MELGs are resilient to perturbations because of both the bonding and the regeneration of functional domains synthesized by living cells. The programmability of the bacteria enables us to fabricate MELGs that can respond to external input, decompose a pollutant, reconstitute synthetic pathways for natural product synthesis, and purify mismatched DNA. Our work establishes a bacteria-assisted grafting strategy to functionalize materials with a broad range of biological activities in an integrated, flexible, and modular manner. A record of this paper's transparent peer review process is included in the supplemental information.

The root-associated Fusarium isolated based on fungal community analysis improves phytoremediation efficiency of Ricinus communis L. in multi metal-contaminated soils.

Phytoremediation is a widely accepted bioremediation method of treating heavy metal contaminated soils. Nevertheless, the remediation efficiency in multi-metal contaminated soils is still unsatisfactory attributable to susceptibility to different metals. To isolate root-associated fungi for improving phytoremediation efficiency in multi-metal contaminated soils, the fungal flora in root endosphere, rhizoplane, rhizosphere of Ricinus communis L. in heavy metal contaminated soils and non-heavy metal contaminated soils were compared by ITS amplicon sequencing, and then the critical fungal strains were isolated and inoculated into host plants to improve phytoremediation efficiency in Cd, Pb, and Zn-contaminated soils. The fungal ITS amplicon sequencing analysis indicated that the fungal community in root endosphere was more susceptible to heavy metals than those in rhizoplane and rhizosphere soils and Fusarium dominated the endophytic fungal community of R. communis L. roots under heavy metal stress. Three endophytic strains (Fusarium sp. F2, Fusarium sp. F8, and Fusarium sp. F14) isolated from Ricinus communis L. roots showed high resistances to multi-metals and possessed growth-promoting characteristics. Biomass and metal extraction amount of R. communis L. with Fusarium sp. F2, Fusarium sp. F8, and Fusarium sp. F14 inoculation in Cd-, Pb- and Zn-contaminated soils were significantly higher than those without the inoculation. The results suggested that fungal community analysis-guided isolation could be employed to obtain desired root-associated fungi for enhancing phytoremediation of multi-metal contaminated soils.

Detecting protein complexes based on relevancy from protein interaction networks.

In protein-protein interaction networks, proteins combine into macromolecular complexes to execute essential functions in the cells, such as replication, transcription, protein transport. To solve the problem of detecting protein complexes from protein interaction networks, we used relevant graph and irrelevant graph to represent the relation of connection between a node and a core graph. We defined a variable Relevancy to represent whether a node had a dense or loose connection to a core graph. Then we proposed the Relevancy Judgment algorithm to detecting protein complexes from protein interaction networks. Our algorithm decided whether a node belonged to a protein complex through judging the relevancy between core graph and nodes out of core graph. Experiment results show that our algorithm has an excellent performance in both accuracy and hit rate.

[Influence of captopril on human sperm motility parameters in vitro].

OBJECTIVE: To determine the effects of captopril on human sperm motility in vitro. METHODS: Sperm specimens were aseptically obtained by masturbation and prepared by Percoll gradient-centrifugation technique to produce a spermatozoa suspension of high motility from 12 healthy fertile men. The spermatozoa suspension were incubated with captopril at 1:9 ratio of volume at 37 degrees C in vitro, which was administrated at three different concentrations. Measurements were carried out within 5 minutes for all specimens including VAP, VSL, VCL, STR, ALH and progressive motility. RESULTS: Within 5 minutes, three different concentrations of captopril could change the human spermatozoa motility and forward motile sperm percentage, but captopril did not decrease the other motility parameters, including VSL, VCL and VAP etc. The high concentration group could decrease the VCL more than those of the other two groups and it seemed that the velocity parameters of the middle concentration group were higher than those of the other two groups, but there were no significant difference statistically. CONCLUSION: It suggests that captopril can decrease the human spermatozoa motility and forward motile sperm percentage, but it can not directly affect the spermatozoa velocity in vitro.