Alnaimat S, Shattal SA, AlthunibatO, Alsbou E, Amasha R. 2017. Iron (II) and other heavy-metal tolerance in bacteria isolated from rock varnish in the arid region of Al-Jafer Basin, Jordan. Biodiversitas 18: 1250-1257. This study deals with enumeration, identification and molecular characterization of bacterial species tolerant of iron (II) and other heavy metals that isolated from rock varnish collected from the arid region of Al-Jafer Basin, Jordan. Based on conventional culture-dependent methods, six isolates exhibited a high degree of tolerance to iron (II) and other heavy metals with a minimum inhibitory concentration (550–600 mg/L) to iron, (500-550 mg/L) to lead, (350 mg/L) to copper, (400-450 mg/L) to chromium, (150-200 mg/L) to silver, and (150-200 mg/L) to mercury, in solid media. The results showed that all isolates could tolerate 2000 mg/L Fe2+ expressed as maximum tolerance concentration (MTC). The multiple metal resistances of these isolates were also associated with multiple antibiotic resistances. These iron tolerant isolates were shown to be capable of growth at temperatures ranging from 30 to 40°C and pH values ranging from 5 to 9 with some differences between the six isolates. On the basis of morphology and of 16S rDNA gene sequencing and phylogeny analysis, the iron-tolerant isolates were identified as Bacillus zhangzhouensis (DVCr1), Staphylococcus warneri (DVCr6), Bacillus cereus (DVCr7), Staphylococcus pasteuri (DVCu2), Brevibacterium frigoritolerans (DVPb) and Bacillus altitudinis (DVCr10). The 16S rDNA sequences from five of the six strains were submitted to GenBank and are available under the accession numbers KX781139, KX781140, KX781141, KX781145 and KX781148. The results highlight the high potential of a non-polluted habitat like rock varnish to provide new microbial communities that could be used for enhanced bioremediation of heavy metals from a contaminated site.

Artemisia herba-alba (AHA), known as sheeh in Jordan, is recommended by regional traditional healers for the treatment of a variety of diseases. AHA has been used in folk medicine to treat colds, coughing, bronchitis, intestinal disturbances, diarrhea, neuralgias, arterial hypertension, and diabetes. The objectives of the current study were to identify the chemical compositions of the essential oil extracted from dried leaf powder of AHA cultivated in Jordan and investigate its antibacterial and antioxidant activities. The essential oil was isolated using hydro distillation, and the identification of artemisia herba-alba essential oil (AHEO) composition was performed using validated gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of AHEO was assessed against escherichia coli, pseudomonas aeruginosa, klebsiella pneumonia, and staphylococcus aureus and two clinical isolates (methicillin-resistant staphylococcus aureus and methicillin-resistant staphylococcus epidermidis [MRSE]) using a disc diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) values, using the micro-dilution broth method. Additionally, antioxidant activities were determined using DPPH and ABTS radical scavenging assays. The results revealed that the yield of AHEO was 4.41% v/w, with nearly 22 identified compounds, constituting approximately 96.80% of the total mass of essential oils. Monoterpenoids was the major compounds (71.90%), with alpha pinene being the major component, accounting for 17.20% of the composition. The total phenolic and flavonoid contents were 43.97 mg GAE/g and 30.11 mg CE/g, respectively. The antibacterial activity of AHEO against MRSE exhibited the highest inhibitory effect, while E.coli showed the highest MBC value. Furthermore, AHEO demonstrated significant antioxidant activity (IC50= 64.57 and 34.01 for DPPH and ABTS, respectively). The results indicate that AHEO possess good antioxidant and antibacterial properties, suggesting that they may be used as a supplementary food and antimicrobial agent.

Desert environments harbor unique microbial communities. This study focuses on Cellulosimicrobium funkei isolate RVMD1, isolated from rock varnish in the Ma’an Desert. Initial identification was achieved using 16S rRNA gene sequencing, followed by whole-genome sequencing (WGS) for comprehensive characterization. The genome comprises 4,264,015 base pairs (857 contigs) with a high G + C content of 74.59%. A total of 4,449 proteins were predicted. Comparative analysis utilizing OrthoANI, ANI, AAI, and dDDH metrics suggests that RVMD1 belongs to the C. cellulans group, with the highest similarity to C. funkei (97.71% ANI). Phylogenomic analysis of 43 Cellulosimicrobium genomes revealed significant heterogeneity within the genus. Our results challenge current systematics, with C. cellulans potentially representing up to 9 distinct genomospecies. Isolate RVMD1 shows genetic adaptations to its desert environment, including genes for denitrification, oxygen and sulfur cycling, and diverse hydrogen metabolism. Pangenomic analysis uncovered a considerable number of unique genes within RVMD1, highlighting its genetic distinctiveness. Gene family expansions suggest evolution in response to stressors like UV radiation and nutrient limitation. This study represents the first whole-genome analysis of a bacterium isolated from Jordanian rock varnish, emphasizing the value of WGS in understanding microbial diversity and adaptation in extreme environments.

Bismuth salicylate was found to inhibit the growth of a range of bacteria and yeast, "Candida albicans". In general the growth of bacteria did not result in increase in bismuth solubilisation, in contrast, bismuth solubilisation increased following the growth of C. albicans. A significant increase in the biomass (dry weight) of Aspergillus niger and Aspergillus oryzae occurred in vitro when these fungi were grown in the presence of bismuth salicylate. Biomass increase occurred over a range of bismuth compound additions, which in the case of A. oryzae was associated with increase in the solubilisation of the insoluble bismuth compounds.

Thymoquinone (TQ), the active constituent of Nigella sativa, possesses several benefits in traditional and modern medicines. This study examined the effect of a single dose of Nano‐TQ on chronic lung injury induced by repetitive intratracheal installation of lipopolysaccharide (LPS). Rats received LPS twice weekly for 8 weeks via intratracheal installation and a single dose of TQ‐PLGA NPs on the day after the last dose of LPS. Six rats from each group were sacrificed after 8 and 10 weeks, and samples were collected for analysis. Repetitive intratracheal installation of LPS caused histopathological alterations, including partial or complete obstruction of the alveoli, interstitial edema, mild fibroblastic proliferation, fibrous strands besides lymphocytes and plasma infiltrations, suffered fetalization, bronchiectasis, hypertrophied arterioles, and others. Investigation of the ultrastructure revealed prominent necrotic pneumocytes with destructed chromatin and remnant of necrotic debris in the narrowing alveolar lumen in LPS‐induced rats. TQ‐PLGA NPs effectively ameliorated LPS‐induced histopathological and ultrastructural alterations in the lung of rats. In addition, TQ‐PLGA NPs significantly alleviated serum levels of IL‐10 and TGF‐β1 in LPS‐induced rats. In conclusion, TQ‐PLGA NPs prevented inflammation and tissue injury in the lungs of rats challenged with repetitive intratracheal installation of LPS. Therefore, TQ‐PLGA NPs represent a promising candidate for the prevention of lung injury induced by LPS, pending further studies to determine its safety and exact protective mechanism.