Aims: The purpose of this research was to explore the composition and genomic functions of bacterial community inhabiting the rhizosphere of Mimosa pudica, which were naturally growing on tailing and non-tailing soils of an ex-tin mining area. Methodology and results: DNA were extracted from rhizosphere soils and PCR targeting the hypervariable region V3-V4 was carried out by Illumina 16S metagenomic library. Libraries were sequenced using Illumina MiSeq. The Operational Taxonomic Units (OTUs) were assigned to 23 bacterial phyla, 72 classes, 165 orders, 248 families and 357 genera. The most represented and dominant phylum was Proteobacteria, with an average abundance value of 41.2%. The most represented genera included Paraburkholderia, Bradyrhizobium, Bacillus, Candidatus, Acidothermus, Acidibacter and Nitrospira. Non-tailing soils had more number and richness of species while the tailings had more diversity of species. The metagenomes accommodate suspected genes for heavy metal tolerance of microbes (As, Cr, Co, Zn, Ni, Cu, Cd, Fe and Hg) and microbial plant-growth-promoting traits for hyperaccumulator plants (synthesis of indole acetic acid (IAA), siderophore and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase; solubilization of phosphate and potassium and nitrogen fixation). Conclusion, significance and impact of study Bacteria and predicted genes discovered could be part of major factors influencing growth of M. pudica in heavy metal-contaminated soils. The study provides the first report and a basis into the bacterial community associated with M. pudica in ex-tin mining soils from the studied geographical location. The findings also provide fundamental knowledge on phytoremediation potential of heavy metal contaminated soils involving indigenous beneficial microbial populations.
Bacteria ; Rhizosphere ; Mimosa ; Plant Growth Regulators

Aims: The occurrence of bacterial disease in shrimp ponds is a major problem faced in shrimp farming. Thus, the aims of this study were to isolate and evaluate antibiotic resistant profile of Vibrio harveyi strain isolated from shrimp pond water, as well as to study the potential anti-Vibrio activity of Combretum quadrangulare Kurz. (CQ) and Mimosa pudica (MP) leaves extracts. Methodology and results: Vibrio harveyi WSC103 was isolated from water in white shrimp (Litopenaeus vannamei) culture pond and identified using 16S rRNA gene sequencing analysis. This strain showed characteristics of multidrug-resistant (7 antibiotics). It had become more sensitive to antibiotics (9 out of 10 antibiotics) after plasmid curing. It is showed CQ and MP leaves extracts contain potent bioactive compounds (tannins, flavonoids, steroids, cardiac glycosides and alkaloids) against V. harveyi WSC103. The aqueous, 95% ethanolic and 75% acetone extracts of CQ (MIC value of 3.13-12.50 mg/mL) and MP (MIC value of 3.13-25.00 mg/mL) leaves revealed strong vibriostatic activity, but aqueous and 95% ethanolic extracts in both plants showed vibriocidal activity. The 95% ethanolic extract of both CQ and MP leaves displayed the excellent vibriocidal property with MBC value of 100 mg/mL with zone of inhibition at 11.44 ± 1.01 and 11.78 ± 1.01 mm by agar disc diffusion. Conclusion, significance and impact of study The isolated Vibrio harveyi WSC103 was successfully characterized as a novel multidrug-resistant strain. The ethanolic C. quadrangulare Kurz. and M. pudica extracts exhibited prominent vibriostatic and vibriocidal capacities. These finding is proven that C. quadrangulare Kurz. and M. pudica extracts would be an alternative anti-Vibrio agent for aquaculture infectious treatment.
Vibrionaceae ; Gram-Negative Bacteria ; Combretum ; Mimosa

AIMTo study chemical constituents of Mimosa pudica of Hainan province.

METHODSThe constituents were separated and purified by column chromatography with macroporous adsorption resin Diaion HP-20, Sephadex LH-20, Toyopearl HW-40, MCI Gel CHP-20, RP-18 and normal phase silica gel. Their structures were identified on the basis of physical and spectral data.

RESULTSFour compounds were isolated and identified as: 7, 8, 3', 4'-tetrahydroxyl-6-C-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl flavone (I); 5, 7, 4'-trihydroxyl-8-C-[alpha-L-rhamnopyranosyl-( --> 2)]-beta-D-glucopyranosyl flavone (II); 5, 7, 3', 4'-tetrahydroxyl-6-C-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl flavone (III); catcher (IV).

CONCLUSIONCompound I is a new compound and componuds II - IV were isolated from this plant for the first time.

Disaccharides ; chemistry ; isolation & purification ; Flavones ; chemistry ; isolation & purification ; Mimosa ; chemistry ; Molecular Conformation ; Molecular Structure ; Plants, Medicinal ; chemistry