A novel actinomycete strain, designated 12-833^T, was isolated from a crude oil-contaminated site north of Kuwait. The isolated strain showed the ability to degrade crude oil and various hydrocarbons. 16S rRNA gene sequence analysis showed that strain 12-833^T belonged to the genus Prauserella and was closely related to Prauserella muralis 05-Be-005^T (98.3 % 16S rRNA gene sequence similarity), Prauserella marina MS498^T (96.9 %) and Prauserella rugosa DSM 43194^T (96.7 %). The DNA G+C content of strain 12-833^T was 71.1 mol%. Phenotypic, physiological, biochemical and chemotaxonomic characteristics and phylogenetic analysis indicated that strain 12-833^T represents a novel species of the genus Prauserella, for which the name Prauserella soli sp. nov. is proposed. The type strain is 12-833^T ( = DSM 45819^T = LMG 28346^T).

The marine waters of Kuwait are highly dynamic and strongly influenced by extreme environmental conditions and high levels of anthropogenic activities. This study explored the bacterioplankton community composition and diversity in Kuwait Bay and at four offshore sites close to urbanized coastal areas during two seasons, autumn (October) and spring (April). 16S rRNA amplicon sequencing detected higher bacterial diversity and richness in spring than in autumn. Also, bacterial community beta diversity revealed a significant seasonal partitioning between the two sampling periods but no clear spatial variation could be depicted. Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria, Flavobacteriia, and Acidimicrobiia dominated the seasonal samples, and SARII clade Ia, SARII clade II, Synechococcus, and SUP05 cluster were among the most abundant taxa in the seasonal samples. However, the strong temporal shift in bacterial community composition was related to Synechococcus abundance. The prevailing physicochemical parameters displayed a significant influence on the bacterioplankton community composition, which was mainly driven by shifts in temperature and nutrient inputs. Furthermore, functional prediction by PICRUSt analysis revealed a relatively stable conserved functional profile in Kuwait’s waters. However, functional genes related to membrane transport were enriched in eutrophic spring waters, while photosynthetic genes were enriched in autumn. Our results provide in-depth insights into the temporal and spatial variations of bacterioplankton dynamics in Kuwait waters and highlight the strong seasonal influence of natural and anthropogenic stressors on their composition and predicted functional capabilities.

This study investigates the efficiency of different bioremediation techniques in cleaning a desert soil sample saturated with crude oil. The soil was divided into three cores; two cores were regularly irrigated with either tap water or raw sewage effluent and mixed thoroughly, while the third core remained untreated as a control. Three parallel cores of pristine soil samples were also set for comparative analysis of microbial communities. The cores were exposed to natural environmental conditions for 10 months. The results of the study showed that bioremediation in the oil-saturated soil samples occurred via the activities of the indigenous bacteria, demonstrating self-cleaning. Oil-removal efficiency in the untreated soil samples reached 79.6 % after 10 months incubation. Water- and sewage effluent-irrigation along with soil mixing improved the environmental conditions in the polluted soil samples, thus enhancing the growth and propagation of hydrocabonoclastic bacteria, accelerating oil-biodegradation to 94 % and 97.4 %, respectively. Both culture-dependent and culture-independent analyses revealed significant shifts in bacterial community composition due to oil introduction and treatment type. The culture-independent method revealed TM7a, A4b, and Skermanella as the most abundant taxa. Conversely, the culture-dependent method identified Arthrobacter spp., Georgenia sediminis, Mycobacterium doricum, Pseudomonas spp., and Sinorhizobium meliloti as the predominant hydrocarbonoclastic indigenous bacteria in the untreated and water-irrigated soil. In the sewage effluent-irrigated soil, Aeromonas and Enterobacter dominated using the culture-dependent method, while JG30-KF-CM45 was the most abundant, with no coliform detection in the culture-independent method. The current study showed that self-cleaning of oil-saturated soils could be accelerated using cost-efficient methods.

Cyanobacteria are the dominant primary producers in many marine waters, and are intimately connected with the cyanophages that infect them. The most commonly isolated marine cyanophages form a monophyletic group based on several marker genes including g20, a gene that codes the capsid assembly protein. Based on morphology, these viruses are typically referred to as cyanomyoviruses. Here, we used g20 sequences to interrogate the diversity of cyanomyoviruses at 5 locations in the waters of the northwestern Arabian Gulf. The diversity and richness of g20 sequences varied among locations and were highest at the southernmost sites. Most sequences belonged to a small number of operational taxonomic units (OTUs), with the rest belonging to low abundance rare OTUs. Phylogenetic analysis revealed that the most abundant genotypes fell within the ubiquitous cyanomyovirus Cluster II, while others clustered with metagenome assembled pelagimyophage sequences and other environmental sequences across a broad diversity of clades. This study revealed a diverse community of cyanomyoviruses in the northwestern Arabian Gulf that is dominated by a few relatively abundant but phylogenetically diverse taxa.