Moso Bamboo Invasion Reshapes Community Structure of Denitrifying Bacteria in Rhizosphere of Alsophila spinulosa

The uncontrolled invasion of moso bamboo (Phyllostachys pubescens) dramatically alters soil nitrogen cycling and destroys the natural habitat of Alsophila spinulosa. Nevertheless, no clear evidence points out the role of denitrifying bacteria in the invasion of bamboo into the habitat of A. spinulosa. In the present study, we found that low (importance value 0.0008), moderate (0.6551), and high (0.9326) bamboo invasions dramatically altered the underground root biomass of both P. pubescens and A. spinulosa. The root biomass of A. spinulosa was maximal at moderate invasion, indicating that intermediate disturbance might contribute to the growth and survival of the colonized plant. Successful bamboo invasion significantly increased rhizospheric soil available nitrogen content of A. spinulosa, coupled with elevated denitrifying bacterial abundance and diversity. Shewanella, Chitinophaga, and Achromobacter were the primary genera in the three invasions, whereas high bamboo invasion harbored more denitrifying bacteria and higher abundance than moderate and low invasions. Further correlation analysis found that most soil denitrifying bacteria were positively correlated with soil organic matter and available nitrogen but negatively correlated with pH and water content. In addition, our findings illustrated that two denitrifying bacteria, Chitinophaga and Sorangium, might be essential indicators for evaluating the effects of bamboo invasion on the growth of A. spinulosa. Collectively, this study found that moso bamboo invasion could change the nitrogen cycling of colonized habitats through alterations of denitrifying bacteria and provided valuable perspectives for profound recognizing the invasive impacts and mechanisms of bamboo expansion.

Phytochemical Characterization for Quality Control of Phyllostachys pubescens Leaves Using High-Performance Liquid Chromatography Coupled with Diode Array Detector and Tandem Mass Detector

Phyllostachys pubescens leaves are cultivated in a number of Asian countries and have been used for antipyretic and diuretic effects since ancient times, especially in Korea. The purpose of this study was to develop and validate of analytical method for quality control of P. pubescens leaves using high-performance liquid chromatography with diode array detector (HPLC–DAD) and liquid chromatography with tandem mass spectrometry (LC–MS/MS) detection. HPLC–DAD analysis was conducted with a Gemini C18 column, and distilled water–acetonitrile (both with 0.1% (v/v) formic acid) mobile-phase system. For the LC–MS/MS analysis, all markers were separated with a Waters ACQUITY UPLC BEH C18 column and gradient flow system of distilled water containing 0.1% (v/v) formic acid and 5 mM ammonium formate–acetonitrile. In both method, major components were detected at 2.13–11.63 mg/g (HPLC–DAD) and 0.12–19.20 mg/g (LC–MS/MS). These methods were validated with respect to linearity (coefficient of determination >0.99), recovery (95.22–118.81%), accuracy (90.52–116.96), and precision (<4.0%), and were successfully applied for the quantitative analysis of P. pubescens leaves.

O AUMENTO DA RESISTÊNCIA MECÂNICA DOS NÓS DO BAMBU COM REFORÇO DE FIBRA DE VIDRO

O aço tem sua empregabilidade consolidada no setor da construção civil devido suas propriedades físicas e mecânicas, contudo, a sua produção causa grandes danos ambientais em razão do alto consumo de energia que resulta no aumento da emissão de gás carbônico das indústrias, a contaminação de rios com efluentes que são emitidos em sua fabricação, e além de tudo isso, não é uma matéria prima renovável. Buscando alternativas que tenham o mínimo impacto ambiental, sem comprometer o resultado conhecido pelo aço, este trabalho foi desenvolvido apresentando uma pesquisa metodológica do bambu Phyllostachys pubescens com o reforço do nó envolvendo-o com a fibra de vidro para aumentar o seu desempenho, podendo ser considerado uma nova alternativa de material para o uso estrutural na engenharia civil. Devido ao meio ambiente ser cada vez mais cobrado pela sociedade e o mercado consumidor, o setor da construção civil não seria diferente. Para estabelecer um parâmetro comparativo que comprove a melhoria da resistência do bambu com o nó reforçado, serão realizados ensaios de compressão, cisalhamento e tração no bambu Phyllostachys pubescens, os CP’s foram preparados alguns com tratamento natural (imersão em água), tratamento químico (aplicação de cobre, cromo e boro) e sem tratamento. Por fim, pretende-se comprovar o aumento da resistência mecânica com a aplicação da fibra de vidro do nó do bambu para despertar uma curiosidade nos profissionais brasileiros gerando o aumento em seu uso na construção civil e consequentemente ocorrer a normatização nacional, assim como existem em outros países como China e Colômbia.

The mechanical properties and thermal conductivity of bamboo with freeze–thaw treatment

The aim of this research was to investigate the effect of freeze–thaw treatment on bamboo with different initial moisture content (water-saturated, air-dried and oven-dried). Bamboo (Phyllostachys pubescens) were treated with two freeze treatments and its microstructure, chemical composition, mechanical properties and thermal conductivity were characterized by field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), mechanical testing machine and thermal conductivity tester, respectively. The results showed that the freeze–thaw treatment had little influence on the microstructure of bamboo, the chemical composition content and the cellulose crystalline structure of bamboo were also not altered. The crystallinity index was found to increase with the increase of initial moisture content. The bending strength and elastic modulus of the treated bamboo increased, the extent of the increase was dependent on the initial moisture content and the freezing temperature. The thermal conductivity of the treated bamboo increased remarkably, which might be possibly determined by the cellulose crystallinity, moisture content, and density of bamboo.

Phytoextraction of Cr(VI)-Contaminated Soil by Phyllostachys pubescens: A Case Study

This work presents the results of experimental tests to evaluate the effects of prolonged contamination by Cr on Moso Bamboo (MB) (Phyllostachys pubescens) and the adaptability of the MB to the Mediterranean climate. A preliminary test on the MB was developed in the laboratory, simulating irrigation under Mediterranean conditions (600 mm per year) and tropical conditions (1800 mm per year), to evaluate the rate of growth and the MB’s capability for Cr phytoextraction from contaminated soil. The tolerance of MB to Cr was also performed showing a good response of the plant to 100 mg Cr/L solution, utilized for irrigation of the pots. The results show that the rate of MB’s removal of Cr from soil ranged from 49.2% to 61.7% as a function of the soil degree of contamination, which varied from approx. 100 mg/kg to 300 mg/kg. The distribution of Cr in the various sections of the bamboo revealed that the greater percentage was present in rhizomes: 42%, equal to 114 mg Cr for 600 mm per year, and 50%, equal to 412 mg Cr for 1800 mm per year. A noteworthy diffusion of the metal towards the outermost parts of the plant was shown. The values of Cr retained in the stems and leaves of MB tissues were quite high and varied from 1100 mg/kg to 1700 mg/kg dry weight.