No abstract

Heavy metal pollution is one of the threats that impact on Mangrove ecosystem. This study aims to examine if the heavy metals in the mangrove sediment contamination status along the Red Sea coast, and give an interpretation of the origin of these metals. Twenty-two samples were collected and then, analyzed for metals (Mn, Ni, Cu, Fe, Cd, Ag, and Pb) using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Integration between the in-situ data, contamination indices, and remote sensing and geographical information science (GIS), and multivariate statistical analysis techniques (PCA) to assess and clarify the spatial origin of heavy metals in sediment at a regional scale. The average concentration is shown to be substantially lower than the referenced value. The heavy metals are naturally origin not anthropogenic origin and, ranging from moderate to significant except the levels of Ag were very high. According to Ag levels, should be exploited economically. Remote sensing and GIS technique successfully contributed to interpreting the pattern of the origin of heavy metals and discharging systems along the red sea coast.

The haloarchaeal diversity of four hypersaline alkaline lakes from the Wadi El-Natrun depression (Northern Egypt) was investigated in this work using culture-independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) of 16S rRNA gene phylotypes, which was combined with remote sensing and geographic information system (GIS) data to highlight the distribution pattern of the microbial diversity in the water and sediment. The majority of archaeal sequences identified in all four lakes were from the phyla Euryarchaeota and Crenarchaeota; sediment samples from Beida Lake and water samples from El-Hamra Lake had the highest levels of archaeal diversity and sequence similarities of 95% or more were found between six of the acquired clones and uncultured Halorhabdus, Euryarchaeota, and archaeon clones, while two clones shared a high level of sequence similarity (97%) with unclassified archaea, and the other nine clones exhibited 96% to 99% sequence similarity with uncultured archaeon clones, whereas only one showed 97% identity with an uncultured Crenarchaeota. Likewise, 7 DGGE bands had a sequence similarity of 90 to 98% to Halogranum sp., Halalkalicoccus tibetensis, Halalkalicoccus jeotgali, uncultured Halorubrum, Halobacteriaceae sp., or uncultured haloarchaeon. As a result, while the variety of alkaliphilic haloarchaea in the examined soda lakes was restricted, the possibility of uncovering novel species for biotechnological applications from these extreme habitats remains promising.