Greenhouse gas emissions from African lakes are no longer a blind spot

peer reviewedNatural lakes are thought to be globally important sources of greenhouse gases (CO2, CH4, and N2O) to the atmo-sphere although nearly no data have been previously reported from Africa. We collected CO2, CH4, and N2O data in 24 African lakes that accounted for 49% of total lacustrine surface area of the African continent and covered a wide range of morphology and productivity. The surface water concentrations of dissolved CO2 were much lower than values attributed in current literature to tropical lakes and lower than in boreal systems because of a higher productivity. In contrast, surface water–dissolved CH4 concentrations were generally higher than in boreal sys-tems. The lowest CO2 and the highest CH4 concentrations were observed in the more shallow and productive lakes. Emissions of CO2 may likely have been substantially overestimated by a factor between 9 and 18 in African lakes and between 6 and 26 in pan-tropical lakes.AFRIVA

Performance of various cyanide degrading bacteria on the biodegradation of free cyanide in water

This study reports on the biodegradation of free cyanide (FCN) by cyanide degrading bacteria (CDB) that were isolated from mining wastewater and thiocyanate containing wastewater. The performance of these isolates was compared to cryopreserved CDBs that were used in previous studies. The performance of the isolates to degrade FCN was studied in batch cultures. It was observed that the CDB from the thiocyanate wastewater showed higher biodegradation rates (2.114 g CN−. L−1.O.D600 nm−1.h−1) compared to the isolates from the mining wastewater. The isolates from the cryopreserved CDBs and from the mining wastewater achieved a biodegradation rate of 1.285 g CN− L−1.O.D600 nm−1.h−1 and 1.209 g CN−.L−1.O.D600 nm−1.h−1, respectively. This study demonstrated that the source of the organisms plays a significant role on FCN biodegradatio