CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2015
·Vol. 31
·期 4
·645-650
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IF 0.875
Geng Zhi,Zhu Suiyi,Yu Yang,Lu Ying,Lin Rao,Guo Shujun,Bian Dejun,Yang Xia,Huo Mingxin,Huo Hongliang
Novel matrix beads for the immobilization of strain Comamonas testosteroni sp. bdq06 to degrade quinoline were fabricated from polyethersulfone(PES). The beads have an average size of 3 mm and a surface dense layer of 20 microns. To help adhesion and proliferation of bacterial cells, the surfaces of the PES beads were etched, and numerous holes about 1.5 micrometers in diameter were generated as tunnels for cell colonizing in the larger internal cavities of about 5 micrometers in diameter. The quinoline degradation was remarkably enhanced by the cells immobilized in PES beads compared with that by the free cells at pH 5.0 or 10.0 and a temperature of 40 °C. The enhanced degradation of quinoline was contributed to the biofilm on the surface of PES beads, resulting in the significant reduction of retention time from 9 h to 2 h. Furthermore, the beads remain intact after the ultrasonic treatment of them for 30 min or recycling 50 times, indicating that they have excellent mechanical strength, flexibility and swelling capacity. Thus, PES beads have great potential to be matrix for the cell immobilization in bioaugmentation.
研究领域:
环境生物学
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微生物学
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DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
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2020
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IF 4.389
Shanshan Yang,Yichao Wu,Chenchen Qu,Jeremy B. Fein,Yizhuang He,Qiaoyun Huang,Peng Cai
Cyclic diguanylate monophosphate (c-di-GMP) is a ubiquitous intracellular secondary messenger which governs the transition from a bacterial cell’s planktonic state to biofilm formation by stimulating the production of a variety of exopolysaccharide material by the bacterial cell. A range of genes involved in c-di-GMP signaling in the Gram-negative species Comamonas testosteroni have been identified previously, yet the physical-chemical properties of the produced extracellular polymeric substances (EPS) and the bacterial adhesion characteristics regulated by c-di-GMP are not well understood. Here, we modulated the in vivo c-di-GMP levels of Comamonas testosteroni WDL7 through diguanylate cyclase (YedQ) and phosphodiesterase (YhjH) gene editing. The strains and their adhesion properties were characterized by Fourier-transform infrared and two-dimensional correlation spectroscopy analysis (FTIR-2D CoS), contact angle and zeta potential measurements, atomic force microscopy (AFM) and extended-Derjaguin-Landau-Verwey-Overbeek (ExDLVO) analysis. Our results show that high c-di-GMP levels promoted the secretion of long-chain hydrophobic and electroneutral extracellular polysaccharides and proteins. The protein molecules on WDL7/pYedQ2 promoted the bacterial self-aggregation and adhesion onto negatively charged surfaces. In contrast, the reduction of intracellular c-di-GMP concentrations resulted in a nearly 80 % decrease in the adhesion of bacterial cells, although little change in the surface hydrophobicity or surface charge properties were observed for these cells relative to the wild type. These results indicate that the reduced adsorption of WDL7/YhjH that we observed may be caused by the flagellum-accelerated mobility at low c-di-GMP concentrations. Taken together, these results improve our mechanistic understanding of the effects of c-di-GMP in controlling bacterial physical-chemical properties and initial biofilm development.
研究领域:
微生物学
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分子生物学
·
生物物理化学
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DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2025
·
IF 7.8
Rongting Yang,Chao Xue,Kaiqiang Li,Ronghao Wu,Zuliang Chen
Nitrogen pollution in aquaculture wastewater poses significant environmental challenges, with traditional chemical and physical methods proving insufficient for comprehensive mitigation. This study investigates the potential of Comamonas testosteroni FJ17, a heterotrophic nitrogen-removing bacterium, to address nitrogen pollution through biological means. Optimization experiments revealed that strain FJ17 achieved maximum nitrogen removal efficiency (TN=91.5 %) under the following conditions: sodium lactate as the carbon source, a C/N radio of 15, an N/P radio of 20, an inoculum size of 3 %, unadjusted pH, a temperature of 30 °C, and a shaking speed of 150 rpm. Nitrogen balance analysis and RT-qPCR studies indicated that the cell primarily assimilates ammonia nitrogen into biomass, with a minor portion undergoing nitrification and denitrification to release gaseous nitrogen. Additionally, nitrogen content and morphological analysis of extracellular polymeric substances (EPS) highlighted their adsorption role in the removal of ammonia. Finally, a sequencing batch reactor (SBR) was established with a hydraulic retention time (HRT) of 12 h, an influent ammonia concentration of 100 mg/L, and an aeration volume of 15 L/h. Long-term operation demonstrated that the effluent ammonia and total nitrogen (TN) concentrations met China's primary municipal wastewater discharge standards. Highlighted in this study is the potential of C. testosteroni FJ17 to be an effective biological agent for nitrogen removal in aquaculture wastewater.
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高影响因子
BIOTECHNOLOGY & BIOTECHNOLOGICAL EQUIPMENT
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2019
·
IF 1.097
Yu Wang,Huanhuan Shao,Suiyi Zhu,Kejian Tian,Qing Qiu,Hongliang Huo
In this study, we investigated environmental oestrogen 17β-estradiol (E2) degradation by a mixed culture of Rhodococcus equi DSSKP-R-001(RS) and Comamonas testosteroni QYY20150409(CT). The results demonstrated that the two strains exhibited synergistic E2 degradation activity, showing that multispecies bacterial systems can improve microbial survival and activity. The E2 degradation rate for the mixed culture system was 94% under conditions in which E2 was the sole source of carbon and growth energy, while the degradation rates of the R. equi DSSKP-R-001 and C. testosteroni QYY20150409 single strains were 86% and 76%, respectively. Comparing and analyzing the degradation products of E2, intermediate cross-metabolism products were observed in the culture containing the two bacteria. The metabolic products of benzene were essentially removed during the process of E2 degradation in the mixed culture, which showed stronger degradation ability than cultures of the individual strains. The results from this investigation on the degradation of E2 by individual and mixed bacterial cultures provide a theoretical basis for the microbial remediation of environmental oestrogens.
研究领域:
环境科学
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微生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）