First report of anatoxin-a encoding gene in isolated cyanobacterial strains from Malaysia

@#Aims:This study focus on the presence of cyanobacterial toxin in Malaysia and anatoxin-a-encoding gene was detected in this study and the status of cyanobacterial toxins in Malaysia can now be clarified.Methodology and results:As part of status determination of cyanobacterial toxins in Malaysia, cyanobacterial strains have been isolated from different environments and identified using cyanobacterial16S rRNA gene sequence. PCR assay was carried out to detect the presence of cyanobacterial toxin-encoding genes in these isolated strains by amplifying genes encoded for microcystin, anatoxin-a, cylindrospermopsin and saxitoxin. Using molecular identification of 16S rRNA gene sequences, a total of forty-two cyanobacterial strains were identified, which belongs to eighteen different genera of Synechococcus, Cyanobium, Synechocystis, Chroococcidiopsis, Leptolyngbya, Nodosilinea, Limnothrix, Pseudanabaena, Cephalothrix, Aerosakkonema, Oscillatoria, Alkalinema, Pantanalinema, Planktolyngbya, Scytonema, Nostoc, Hapalosiphonand Symphyonemopsis. The toxicity of these strains was tested using PCR amplification of toxin-encoding genes using specific primers.Conclusion, significance and impact of study:Anatoxin-a (ATX) gene,which involved in the biosynthesis of anatoxin-Awas detected in two isolated strains namelyLimnothrixsp. B15 and Leptolyngbyasp. D1C10.This study focus on the the presence of cyanobacterial toxin in Malaysia can now be determined as potential threat because anatoxin-a-encoding gene was detected in this study and the status of cyanobacterial toxins in Malaysia can now be clarified.

The behaviour of membrane less sediment microbial fuel cell in the terms of bioremediation and power generation 108-112

@#Aims: To study the performance of SMFC in the terms of power generation and toxic metals removal. This study was also focused on the characterization of SMFC electro-microbiology. Methodology and results: A SMFC was designed and loaded with sediment and overlying water. This SMFC was synchronized with wireless data logger acquisition system. The toxic metals removal capacity was measured by atomic absorption spectroscopy. The characterization of SMFC bacteria was done by 16S rRNA.In this study the experiments were carried out in a dual-chamber SMFC with external resistances 30 kΩ-50 Ω. The SMFC was produced power about 630 mV with maximum power density 40 mW/m2and current density 250 mA/m2. After 120 days of operation, SMFC removed cadmium and copper about 22.6 and 150 mg/kg, respectively. The SMFC also showed high cadmium (86%) and copper (90%) removal at pH 7.0 and temperature 40 °C. The most dominant bacterial community at anode and cathode was identified as Pseudomonas spp. which could be function as exoelectrogen. Conclusion, significance and impact of the study: The results indicated that the SMFC system could be applied as a long term and effective tool for the removal of cadmium and copper contaminated sediments and supply power for commercial devices. The Pseudomonas spp. may be used as a genetic donor for the other non-exoelectrogens strains.