RESUMO
Legume plants form symbiotic relationships with rhizobia, which allow plants to utilize atmospheric nitrogen as a nutrient. This symbiosis is initiated by secretion of specific signaling metabolites from the roots, which induce the expression of nod genes in rhizobia. These metabolites are called nod gene inducers (NGIs), and various flavonoids have been found to act as NGIs. However, NGIs of chickpea, the second major pulse crop, remain elusive. We conducted untargeted metabolome analysis of chickpea root exudates to explore metabolites with increased secretion under nitrogen deficiency. Principal component (PC) analysis showed a clear difference between nitrogen deficiency and control, with PC1 alone accounting for 37.5% of the variance. The intensity of two features with the highest PC1 loading values significantly increased under nitrogen deficiency; two prominent peaks were identified as O-methylated isoflavones, pratensein and biochanin A. RNA-seq analysis showed that they induce nodABC gene expression in the Mesorhizobium ciceri symbiont, suggesting that pratensein and biochanin A are chickpea NGIs. Pratensein applied concurrently with M. ciceri at sowing promoted chickpea nodulation. These results demonstrate that pratensein and biochanin A are chickpea NGIs, and pratensein can be useful for increasing nodulation efficiency in chickpea production.
Assuntos
Cicer , Isoflavonas , Mesorhizobium , Nodulação , Simbiose , Cicer/microbiologia , Cicer/genética , Cicer/metabolismo , Isoflavonas/metabolismo , Isoflavonas/farmacologia , Mesorhizobium/genética , Mesorhizobium/metabolismo , Mesorhizobium/fisiologia , Nodulação/genética , Nodulação/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/química , Raízes de Plantas/genética , Metilação , Genisteína/metabolismo , Genisteína/farmacologiaRESUMO
The umbilicus accumulates more dirt than other body surfaces and is difficult to clean. Hygiene in this area is vital, particularly for surgery, because of its proximity to the laparotomy site. Although microorganisms in the umbilicus have been extensively examined, those in umbilical dirt have not due to the lack of an efficient method of collection. We previously established a technique to extract umbilical dirt using the anchor effect of polymers, which are injected into the umbilicus. In the present study, we applied this technique for the first time to investigate umbilical dirt. The results obtained revealed an abundance of Corynebacterium among various bacteria, whereas Cutibacterium and Staphylococcus, which are abundant at other skin sites, were rare. The relationships between the microbiota and issues related to the umbilicus were investigated and some covariates, including the odor score and several bacteria, were identified. A detailed ana-lysis of the genera associated with odor revealed no correlation with Corynebacterium; however, some minor anaerobic bacteria, such as Mobiluncus, Arcanobacterium, and Peptoniphilus, were more abundant in the high odor score group. Therefore, this technique to collect umbilical dirt provided insights into the microbiota in umbilical dirt and suggested functions for minor anaerobes. Furthermore, since various pathogenic microorganisms were detected, their control may contribute to the prevention of both odor production and infectious diseases caused by these microorganisms.
Assuntos
Microbiota , Umbigo , Odorantes , Bactérias/genética , Bactérias Anaeróbias , RNA Ribossômico 16SRESUMO
Towels differ remarkably from other textile products in their fibre structure and usage, and microbial behaviours on towels remain underexplored. Thus, we evaluated biofilm formation on towels during use for 6 months in daily life and analysed its relationship with odour, dullness, and laundry habits. The towels exhibited odour and dullness after 2 months of use and biofilm structures were observed over the 6 months, especially in the ground warp part. Polysaccharides, proteins, nucleic acids, and viable counts on the towels increased over time. The microbiota was significantly different from that on human skin and clothing. Several species of Alphaproteobacteria were correlated with dullness intensity and the quantity of biofilm components. Therefore, bacterial species that specifically adapt to the towel fibre environment could form biofilms. Our results demonstrate bacterial diversity in textile products and suggest careful consideration of the textile fibre material, structure, and usage pattern to control bacterial communities.
Assuntos
Alphaproteobacteria , Microbiota , Humanos , Bactérias , BiofilmesRESUMO
The genus Methylobacterium tolerates hygiene agents like benzalkonium chloride (BAC), and infection with this organism is an important public health issue. Here, we found that the combination of BAC with particular alcohols at nonlethal concentrations in terms of their solitary uses significantly reduced bacterial viability after only 5 min of exposure. Among the alcohols, Raman spectroscopic analyses showed that pentanol (pentyl alcohol [PeA]) and benzyl alcohol (BzA) accelerated the cellular accumulation of BAC. Fluorescence spectroscopic assays and morphological assays with giant vesicles indicated that PeA rarely attacked membrane structures, while BzA increased the membrane fluidity and destabilized the structures. Other fluorescent spectroscopic assays indicated that PeA and BzA inactivate bacterial membrane proteins, including an efflux pump for BAC transportation. These findings suggested that the inactivation of membrane proteins by PeA and BzA led to the cellular accumulation but that only BzA also enhanced BAC penetration by membrane fluidization at nonlethal concentrations.
Assuntos
Anti-Infecciosos Locais/farmacologia , Compostos de Benzalcônio/farmacologia , Álcool Benzílico/farmacologia , Methylobacterium/citologia , Methylobacterium/efeitos dos fármacos , Pentanóis/farmacologia , Combinação de Medicamentos , Sinergismo Farmacológico , Humanos , Fluidez de Membrana/efeitos dos fármacos , Proteínas de Membrana/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Espectrometria de FluorescênciaRESUMO
A comprehensive survey of microbial flora within pink biofilms in bathrooms was performed. Pink biofilms develop relatively rapidly in bathrooms, can be difficult to remove, and are quick to recur. Bacterium-sized cells were found to be predominant in 42 pink biofilms in Japan using a scanning electron microscope. Methylobacterium strains were detected from all samples in bathrooms by an isolation method. To explain this predominance, 14 biofilm samples were analyzed by fluorescence in situ hybridization. Methylobacterium was indicated to be the major genus in all biofilms. The isolated Methylobacterium survived after contact with 1.0% cleaning agents, including benzalkonium chloride for 24 h. Their tolerance did not differ under biofilm-like conditions on fiber reinforced plastics (FRP), a general material of bath tubs, floors, and walls. Also, the strains exhibited higher tolerance to desiccation than other isolated species on FRP. Some Methylobacterium survived and exhibited potential to grow after four weeks of desiccation without any nutrients. These specific characteristics could be a cause of their predominance in bathrooms, an environment with rapid flowing water, drying, low nutrients, and occasional exposure to cleaning agents.