Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Research on Microbes
Microbiology Experts
Online Submission
Access Statistics

Site Visitors

blog tracking

Abstracts of Recent Publications
Abstracts 1 2 3 4 5  

001-Richard YC. Kong, Mandy MH. Maka and Rudolf SS. Wu. Department of Biology and Chemistry and MERIT, City University of Hong Kong. DNA technologies for monitoring waterborne pathogens: A revolution in water pollution monitoring. Ocecoaman. Article in Press, 2009.

Due to increasing population growth and anthropogenic pollution in the coastal zone, contamination of water and seafood with pathogens is probably responsible for the greatest number of human morbidities and mortalities worldwide. Hence, regular monitoring of waterborne pathogens is required to safeguard public health. Current techniques rely on the culturing of nonpathogenic indicator organisms (e.g. Escherichia coli or coliforms) for detection by inference. However, recent epidemiological evidence shows poor correlation between concentrations of E. coli / coliform and waterborne pathogens. Moreover, traditional methods are slow, not cost effective, unable to distinguish harmful from benign strains, and fail to detect viable but nonculturable pathogens. The use of the polymerase chain reaction (PCR) has provided rapid and highly sensitive methods for the specific detection of pathogenic microorganisms. This paper briefly reviews some DNA-based technologies for waterborne pathogen detection, and describes our recent development of two new DNA-based technologies quantitative multiplex-PCR (Q-mPCR) and DNA microarray that allow simultaneous and cost-effective detection and quantification of numerous pathogens in a single sample, which is superior to the culture methods currently in use.

Keywords: Bacteria; Pathogen; Quantitative multiplex-PCR; DNA microarray; Marine water.

002-Haiping Luo, Guangli Liu, Renduo Zhang and Song Jin. School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275, China. Phenol degradation in microbial fuel cells. Chemical Engineering Journal, 147(2-3), 2009,259-264.

Microbial fuel cell (MFC) has gained a great attention attributable to its ability in generating electricity directly from and potentially enhancing biodegradation of contaminants. In this study, MFCs using phenol or glucose-phenol mixture as the substrate (fuel) were designed to investigate the biodegradation of phenol. In an aqueous air cathode MFC using phenol (400 mg/L) as the sole fuel, electricity was generated during the phenol degradation. The degradation rates of phenol in the MFC increased about 15% as compared to the open-circuit control. Further experiments were conducted by using a graphite-packed MFC with a ferricyanide cathode. When phenol served as the sole fuel, the peak voltage output was obtained when 90% of phenol was depleted.

A unique pattern of twin voltage peaks was observed when phenol-glucose mixture was used as the fuel. At the occurrence of the first and second voltage peaks, phenol was degraded by 20% and 90%, respectively, suggesting a preferential sequence in substrate consumption. The maximal power densities were 9.1 and 28.3 W/m3 for MFCs using phenol and glucose-phenol mixture as the fuel, respectively. Co-occurring with electricity generation, the degradation efficiencies of phenol in all the MFCs reached above 95% within 60 h. The results indicate that the MFC can enhance biodegradation of recalcitrant contaminants such as phenol in practical applications.

Keywords:Electricity generation; Microbial fuel cell; MFC; Phenol degradation; Biodegradation.


003-Benoit Van Aken. Department of Civil and Environmental Engineering, West Virginia University, Morgantown, WV 26506, USA. Transgenic plants for enhanced phytore-mediation of toxic explosives. Current Opinion in Biotechnology. Article in Press, 2009.

Phytoremediation of organic pollutants, such as explosives, is often a slow and incomplete process, potentially leading to the accumulation of toxic metabolites that can be further introduced into the food chain. During the past decade, plants have been genetically modified to overcome the inherent limitations of plant detoxification capabilities, following a strategy similar to the development of transgenic crop. Bacterial genes encoding enzymes involved in the breakdown of explosives, such as nitroreductase and cytochrome P450, have been introduced in higher plants, resulting in significant enhancement of plant tolerance, uptake, and detoxification performances. Transgenic plants exhibiting biodegradation capabilities of microorganisms bring the promise of an efficient and environmental-friendly technology for cleaning up polluted soils.

Keywords:Transgenic plants;  Phytoremediation; Toxic explosives; Transgenic.


004- Susana Rodriguez Couto. Department of Chemical Engineering, Rovirai Virgili University, Av. Pai'sos Catalans 26, 43007 Tarragona, Spain. Dye    removal    by    immobilized    fungi.Biotechnology Advances, 27(3), 2009,227-235.

Dyes are widely used within the food, pharmaceutical, cosmetic, printing, textile and leather industries. This has resulted in the discharge of highly coloured effluents that affect water transparency and gas solubility in water bodies. Furthermore, they pose a problem because of their carcinogenicity and toxicity. Therefore, removal of such dyes before discharging them into natural water streams is essential. For this, appropriate treatment technologies are required. The treatment of recalcitrant and toxic dyes with traditional technologies is not always effective or may not be environmentally friendly. This has impelled the search for alternative technologies such as biodegradation with fungi. In particular, ligninolytic fungi and their non-specific oxidative enzymes have been reported to be responsible for the decolouration of different synthetic dyes. Thus, the use of such fungi is becoming a promising alternative to replace or complement the current technologies for dye removal. Processes using immobilized growing cells seem to be more promising than those with free cells, since the immobilization allows using the microbial cells repeatedly and continuously. This paper reviews the application of fungal immobilization to dye removal.

Keywords:Decolouration; Immobilization; Synthetic dyes; White-rot fungi.


005-Steven A. Wakelin, Adrienne L. Gregg, Richard J. Simpson, Guandgi D. Li, Ian T. Riley and Alan C. McKay. CSIRO Land and Water, PMB 2, Glen Osmond, South Australia 5064, Australia. Pasture management clearly affects soil microbial community structure and N-cycling bacteria. Pedobiologia, 52 (4), 2009,237-251.

There may be significant benefits to understanding and managing microbial processes in pasture soils. Direct benefits include increased production, but microbial processes also affect the sustainability and environmental impact of production systems. The first step towards achieving such gains is identifying the components of the soil microbial community most responsive to pasture management. We used molecular tools (DGGE and TRFLP) to assess the impacts  of pasture type,  grazing,  liming,  P fertilisation and sampling date on the structure of the soil bacterial and fungal communities. Furthermore, the response of bacteria involved in defined ecosystem processes was determined by quantifying genes (qPCR) involved in nitrogen fixation (nifH), nitrification (amoA) and denitrification (narG). The strongest factor affecting the structure of the soil microbial community was liming of acidic soil at the Book Book (New South Wales) field trial site (R > 0.95; P < 0.001). Effects of pasture type (annual vs. perennial) were minor. Addition of lime (management of soil pH) increased the richness of fungal phylotypes (Margalefs index; P = 0.017) but not bacterial phylotypes. Liming also increased the biological capacity for nitrogen fixation and nitrification (P < 0.05). Across all treatments, there was a very good correlation between previous measures of N2 fixed at the site and nifH gene abundance data (R2 = 0.81). The biological capacity for denitrification did not respond to pasture management. At a field site near Hall (Australian Capital Territory), an increase in the intensity of pasture production by phosphorus (P) fertiliser addition or increased stocking rate also affected the structure of the soil fungal and bacterial communities (R = 0.8; P < 0.001) and increased fungal phylotype richness (P < 0.05). Significant shifts in the soil biota also occurred during the growing season (P = 0.001). These observations may have been strengthened by the onset of drought conditions from July 2006. Richness of fungal, but not bacterial phylotypes, increased with P fertilisation, stocking rate, and between sampling times (P < 0.05). The increase in fungal phylotypes richness was in direct contrast to a reduction in botanical diversity. Temporal variation in fungal richness was positively correlated with monthly rainfall (R2 = 0.774). The biological capacity for nitrification and denitrification increased with intensification of the system (P < 0.05), but the biological capacity for N, fixation increased with stocking rate only (P < 0.05). Overall, results showed that soil biota under pastures, and particularly soil fungi, are highly responsive to agricultural management treatments.

Keywords:amoA; DGGE; Microbial ecology; nifH; narG; TRFLP.


ENVIS CENTRE Newsletter Vol.7, No 2 April 2009 Back 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution