The Development and Application of DDPCR Technology on Quantification of Total Coliforms in Water
Wei Ma,
Yi Jun Kong,
Weng U Ho,
Si Ian Lam,
Gui Huan Liu,
Sin Neng Chio
Issue:
Volume 9, Issue 2, April 2020
Pages:
22-30
Received:
15 April 2020
Accepted:
30 April 2020
Published:
14 May 2020
Abstract: In this research, the detection method for absolute quantification of total coliforms was established based on Droplet Digital Polymerase Chain Reaction (DDPCR) technology using lacZ as the target gene for coliform group detection. The experimental conditions (e.g. primer and probe concentrations, annealing temperatures, etc) were well optimized. Besides, the linear range, precision and limit of quantification (LOQ) of this method were investigated and evaluated. The results illustrated that the optimal primer concentration was 0.2 μmol/L, whereas the optimal probe concentration was 0.5 μmol/L. The optimal annealing temperature was 56°C. The linear relationship between the total coliform genome DNA concentrations derived from DDPCR and DNA fluorometer was quite good (R2 = 0.999). The linear range was 3.95 ~ 7.80 × 104 copies/20 μL DDPCR reaction system. The LOQ for total coliforms was single copy per reaction system. Practical applications using real water samples collected from water supply system in Macao illustrated that this innovative method possessed high efficiencies and capabilities. This is probably the first research using DDPCR technology to absolutely qualify and quantify total coliforms and successfully applied it in Macao water supply system. The achievements from this research could provide with significant values for setting-up the emergency mechanism of water pollution in early stage.
Abstract: In this research, the detection method for absolute quantification of total coliforms was established based on Droplet Digital Polymerase Chain Reaction (DDPCR) technology using lacZ as the target gene for coliform group detection. The experimental conditions (e.g. primer and probe concentrations, annealing temperatures, etc) were well optimized. B...
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Threats and Conservation Strategies on Urban Wetlands: A Case of Monavale and Surrounding Areas in Harare, Zimbabwe
Silipiwe Sharai,
Tarakini Tawanda,
Chibememe Gladman
Issue:
Volume 9, Issue 2, April 2020
Pages:
31-38
Received:
20 April 2020
Accepted:
5 May 2020
Published:
27 May 2020
Abstract: Wetlands are valuable ecosystems on which humans depend through the utilisation of the ecological goods and services including water for domestic and commercial use. Until recently, efforts on wetland conservation have shifted to community participation since they are important stakeholders in using wetland resources. This study solicited local people’s perceptions on 1) threats to the Monavale wetland (Harare, Zimbabwe), 2) the conservation strategies they perceive most appropriate and 3) the likely consequences of losing this wetland. The study used 80 household questionnaires that were administered to four suburbs (representing three wards) surrounding Monavale, with respondents having different socio-demographic variables (age, ward, employment status and education level). Chi-square tests were used to test for associations between perceived threats across all variables. Multiple Correspondence Analysis was performed to explore relationships between respondents’ socio-demographic variables with 1) goods and services, and 2) perceived consequences of losing Monavale wetland. Main threats cited were agriculture and housing development projects (43 and 36% of respondents respectively). People from wards 5 and 7 cited mostly socio-economic whilst ward 16 cited ecological related goods and services. The respondents’ age was associated with perceptions towards the threats facing Monavale wetland (χ2=31.563, d. f=12, P=0.002). Respondents cited 5 pieces of legislation with Environmental Management Act being the most (75% of respondents) which they think could be better implemented if wetland conservation is to be achieved. The study concludes that, there is need to integrate all relevant stakeholders in wetland conservation for effective legislation implementation as well as increasing educational awareness to both communities and policy makers.
Abstract: Wetlands are valuable ecosystems on which humans depend through the utilisation of the ecological goods and services including water for domestic and commercial use. Until recently, efforts on wetland conservation have shifted to community participation since they are important stakeholders in using wetland resources. This study solicited local peo...
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