Molecular characterization and phylogenetic diversity of actinomycetota species isolated from Lake Natron sediments at Arusha, Tanzania.

Soda lakes are naturally occurring ecosystems characterized by extreme environmental conditions especially high pH and salinity levels but harboring valuable microbial communities with medical and biotechnological potentials. Lake Natron is one of the soda lakes situated in eastern branch of the East African Gregory Rift valley, Tanzania. In this study, the taxonomy and phylogenetic diversity of Actinomycetota species were explored in Lake Natron using molecular techniques.

Spatial and temporal variations of phytoplankton composition and biomass in Lake Bunyonyi, South-Western Uganda.

The purpose of this study was to examine the spatial and temporal variations of phytoplankton species composition and biomass in Lake Bunyonyi, South-Western Uganda. Samples were collected monthly from nine fixed stations in the lake from October 2019 to September 2020. Based on the morphological characterization, 52 different species of phytoplankton were recorded.

Spatial and temporal variations of faecal indicator bacteria in Lake Bunyonyi, South-Western Uganda.

Microbial water quality serves to indicate health risks associated with the consumption of contaminated water. Nevertheless, little is known about the microbiological characteristics of water in Lake Bunyonyi. This study was therefore undertaken to examine the spatial and temporal variations of faecal indicator bacteria (FIB) in relation to physicochemical parameters in Lake Bunyonyi.

Methane emission and sulfide levels increase in tropical seagrass sediments during temperature stress: A mesocosm experiment.

Climate change-induced ocean warming is expected to greatly affect carbon dynamics and sequestration in vegetated shallow waters, especially in the upper subtidal where water temperatures may fluctuate considerably and can reach high levels at low tides. This might alter the greenhouse gas balance and significantly reduce the carbon sink potential of tropical seagrass meadows. In order to assess such consequences, we simulated temperature stress during low tide exposures by subjecting seagrass plants () and associated sediments to elevated midday temperature spikes (31, 35, 37, 40, and 45°C) for seven consecutive days in an outdoor mesocosm setup.

Shading and simulated grazing increase the sulphide pool and methane emission in a tropical seagrass meadow.

Though seagrass meadows are among the most productive habitats in the world, contributing substantially to long-term carbon storage, studies of the effects of critical disturbances on the fate of carbon sequestered in the sediment and biomass of these meadows are scarce. In a manipulative in situ experiment, we studied the effects of successive loss of seagrass biomass as a result of shading and simulated grazing at two intensity levels on sulphide (HS) content and methane (CH) emission in a tropical seagrass meadow in Zanzibar (Tanzania). In all disturbed treatments, we found a several-fold increase in both the sulphide concentration of the sediment pore-water and the methane emissions from the sediment surface (except for CH emissions in the low-shading treatment).

Toxigenic Vibrio cholerae identified in estuaries of Tanzania using PCR techniques.

The current study assessed the occurrence of the Vibrio cholerae serogroups O1 and O139 in environmental samples along salinity gradients in three selected estuaries of Tanzania both through culture independent methods and by cultured bacteria. Occurrence of V. cholerae was determined by PCR targeting the V.

Epiphytic cyanobacteria of the seagrass Cymodocea rotundata: diversity, diel nifH expression and nitrogenase activity.

Seagrasses are photoautotrophic, ecologically important components of many globally widespread coastal ecosystems, in which combined nitrogen may limit their production. We examined the biodiversity and diazotrophic capacity of microbial epiphytes associated with the phyllosphere of the seagrass Cymodocea rotundata of the Western Indian Ocean. Light microscopy, 16S rRNA and nifH gene analysis revealed the dominance of cyanobacteria in the epiphytic microbial community.

Anaerobic oxidation of dimethylsulfide and methanethiol in mangrove sediments is dominated by sulfate-reducing bacteria.

The oxidation of dimethylsulfide and methanethiol by sulfate-reducing bacteria (SRB) was investigated in Tanzanian mangrove sediments. The rate of dimethylsulfide and methanethiol accumulation in nonamended sediment slurry (control) incubations was very low while in the presence of the inhibitors tungstate and bromoethanesulfonic acid (BES), the accumulation rates ranged from 0.02-0.

Why first-level health workers fail to follow guidelines for managing severe disease in children in the Coast Region, the United Republic of Tanzania.

Objective: To determine why health workers fail to follow integrated management of childhood illness (IMCI) guidelines for severely ill children at first-level outpatient health facilities in rural areas of the United Republic of Tanzania.

Methods: Retrospective and prospective case reviews of severely ill children aged < 5 years were conducted at health facilities in four districts. We ascertained treatment and examined the characteristics associated with referral, conducted follow-up interviews with parents of severely ill children, and gave health workers questionnaires and interviews.

Diversity of methanogenic archaea in a mangrove sediment and isolation of a new Methanococcoides strain.

Mangrove forest sediments produce significant amounts of methane, but the diversity of methanogenic archaea is not well known at present. Therefore, 16S rRNA gene libraries were made using archaea-specific primers and DNA extracted directly from Tanzanian mangrove sediment samples as a template. Analysis of sequence data showed phylotypes closely related to cultivated methylotrophic methanogenic archaea from the marine environment, or distantly related to acetoclastic and hydrogenotrophic methanogenic archaea.