An obligately anaerobic, spore-forming, acidophilic sulfate-reducing bacterium, strain SJ4(T), was isolated from an acid mining effluent decantation pond sediment sample (pH around 3.0). Cells were Gram negative, non-motile, curved rods occurring singly. Strain SJ4(T) grew at pH 3.6-5.5 with an optimum at pH 5.2. Strain SJ4(T) utilized H(2), lactate, pyruvate, glycerol, glucose, and fructose as electron donors. Lactate and glucose were weakly used. Sulfate was used as electron acceptors, but not sulfite, elemental sulfur, arsenate (V), and fumarate. The G + C content of genomic DNA was 42.3 mol% (HPLC). 16S rRNA gene sequence analysis indicated that strain SJ4(T) belonged to the genus Desulfosporosinus within the family Peptococcaceae in the phylum Firmicutes. The level of 16S rRNA gene sequence similarity with other Desulfosporosinus species was 94.7-96.2%, D. orientis DSM 765(T) (similarity of 96.2%) and D. auripigmenti DSM 13351(T) (similarity of 95%) being its closest relatives. DNA-DNA relatedness values with D. orientis and D. auripigmenti were 16.5 and 31.8%, respectively. On the basis of phenotypic, phylogenetic, and genetic characteristics, strain SJ4(T) represents a novel species within the genus Desulfosporosinus, for which the name Desulfosporosinus acidiphilus sp. nov. is proposed. The type strain is SJ4(T) (=DSM 22704(T) = JCM 16185(T)).

Tsetse flies were sampled in three villages of the Campo sleeping sickness focus in South Cameroon. The aim of this study was to investigate the flies' gut bacterial composition using culture-dependent techniques. Out of the 32 flies analyzed (27 Glossina palpalis palpalis, two Glossina pallicera, one Glossina nigrofusca, and two Glossina caliginea), 17 were shown to be inhabited by diverse bacteria belonging to the Proteobacteria, the Firmicutes, or the Bacteroidetes phyla. Phylogenetic analysis based on 16S rRNA gene sequences indicated the presence of 16 bacteria belonging to the genera Acinetobacter (4), Enterobacter (4), Enterococcus (2), Providencia (1), Sphingobacterium (1), Chryseobacterium (1), Lactococcus (1), Staphylococcus (1), and Pseudomonas (1). Using identical bacterial isolation and identification processes, the diversity of the inhabiting bacteria analyzed in tsetse flies sampled in Cameroon was much higher than the diversity found previously in flies collected in Angola. Furthermore, bacterial infection rates differed greatly between the flies from the three sampling areas (Akak, Campo Beach/Ipono, and Mabiogo). Last, the geographic distribution of the different bacteria was highly uneven; two of them identified as Sphingobacterium spp. and Chryseobacterium spp. were only found in Mabiogo. Among the bacteria identified, several are known for their capability to affect the survival of their insect hosts and/or insect vector competence. In some cases, bacteria belonging to a given genus were shown to cluster separately in phylogenetic trees; they could be novel species within their corresponding genus. Therefore, such investigations deserve to be pursued in expanded sampling areas within and outside Cameroon to provide greater insight into the diverse bacteria able to infect tsetse flies given the severe human and animal sickness they transmit.

Magnetotactic bacteria (MTB) mineralize nanosized magnetite or greigite crystals within cells and thus play an important role in the biogeochemical process. Despite decades of research, knowledge of MTB distribution and ecology, notably in areas subjected to oil industry activities, is still limited. In the present study, we investigated the presence of MTB in the Gulf of Fos, French Mediterranean coast, which is subjected to intensive oil industry activities. Microcosms containing sediments/water (1:2, v/v) from several sampling sites were monitored over several weeks. The presence of MTB was revealed in five of eight sites. Diverse and numerous MTB were revealed particularly from one site (named CAR), whilst temporal variations of a homogenous magnetotactic cocci population was shown within the LAV site microcosm over a 4-month period. Phylogenetic analysis revealed that they belonged to Alphaproteobacteria, and a novel genus from the LAV site was evidenced. Among the physicochemical parameters measured, a correlation was shown between the variation of MTB abundance in microcosms and the redox state of sulphur compounds.