To the best of our knowledge, cyanobacterial strains from the Arabian Gulf have never been investigated with respect to their potential for nanoparticle production. Lyngbya majuscula was isolated from the AlOqair area, Al-Ahsa Government, Eastern Province, Kingdom of Saudi Arabia. The cyanobacterium was initially incubated with 1500 mg/mL of HAuCl4 for two days. The blue-green strain turned purple, which indicated the intracellular formation of gold nanoparticles. Prolonged incubation for over two months triggered the extracellular production of nanogold particles. UV-visible spectroscopy measurements indicated the presence of a resonance plasmon band at ~535 nm, whereas electron microscopy scanning indicated the presence of gold nanoparticles with an average diameter of 41.7 ± 0.2 nm. The antioxidant and anti-myocardial infarction activities of the cyanobacterial extract, the gold nanoparticle solution, and a combination of both were investigated in animal models. Isoproterenol (100 mg/kg, SC (sub cutaneous)) was injected into experimental rats for three days to induce a state of myocardial infarction; then the animals were given cyanobacterial extract (200 mg/kg/day, IP (intra peritoneal)), gold nanoparticles (200 mg/kg/day, IP), ora mixture of both for 14 days. Cardiac biomarkers, electrocardiogram (ECG), blood pressure, and antioxidant enzymes were determined as indicators of myocardial infarction. The results showed that isoproterenol elevates ST and QT segments and increases heart rate and serum activities of creatine phosphokinase (CPK), creatine kinase-myocardial bound (CP-MB), and cardiac troponin T (cTnT). It also reduces heart tissue content of glutathione peroxidase (GRx) and superoxide dismutase (SOD), and the arterial pressure indices of systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP). Gold nanoparticles alone or in combination with cyanobacterial extract produced an inhibitory effect on isoproterenol-induced changes in serum cardiac injury markers, ECG, arterial pressure indices, and antioxidant capabilities of the heart.

Prokaryotic organisms of the genus Mycoplasma are characterized by their small body and genome size containing a 0.6-1.35 M bp genome. The genome is noted for its low G+C frequency ranging from 8-40 mol%. The Mycoplasma genus stems from the class Mollicutes (for soft skin), which lacks the cell walls and external motility appendages often present in other bacteria. To date, there are more than 100 known species of Mycoplasma. 34 species have been partially or completely sequenced. Widely known pathogenic species of Mycoplasma include: M. pneumoniae, causing pneumonia and other respiratory disorders, and M. genitalium, which are involved in pelvic inflammatory disease. Because of their small genome size, Mycoplasmas provide researchers a unique model of the minimal genomic requirements to maintain life. As the number of complete Mycoplasma genomes increase, these organisms become more established, thus laying the foundation for mapping evolutionary development. This manuscript provides an overview and update on Mycoplasma research, with particular focus on current genomics.

Cyanothece sp., a coccoid, unicellular, nitrogen-fixing and hydrogen-producing cyanobacterium, has been used in this study to biosynthesize customized gold nanoparticles under certain chemical conditions. The produced gold nanoparticles had a characteristic absorption band at 525–535 nm. Two types of gold nanoparticle, the purple and blue, were formed according to the chemical environment in which the cyanobacterium was grown. Dynamic light scattering was implemented to estimate the size of the purple and blue nanoparticles, which ranged from 80 ± 30 nm and 129 ± 40 nm in diameter, respectively. The highest scattering of laser light was recorded for the blue gold nanoparticles, which was possibly due to their larger size and higher concentration. The appearance of anodic and cathodic peaks in cyclic voltammetric scans of the blue gold nanoparticles reflected the oxidation into gold oxide, followed by the subsequent reduction into the nano metal state. The two produced forms of gold nanoparticles were used to treat isoproterenol-induced myocardial infarction in experimental rats. Both forms of nanoparticles ameliorated myocardial infarction injury, with a slight difference in their curative activity with the purple being more effective. Mechanisms that might explain the curative effect of these nanoparticles on the myocardial infarction were proposed. The morphological, physiological, and biochemical attributes of the Cyanothece sp. cyanobacterium were fundamental for the successful production of “tailored” nanoparticles, and complemented the chemical conditions for the differential biosynthesis process. The present research represents a novel approach to manipulate cyanobacterial cells towards the production of different-sized gold nanoparticles whose curative impacts vary accordingly. This is the first report on that type of manipulated gold nanoparticles biosynthesis which will hopefully open doors for further investigations and biotechnological applications.

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Green nanotechnology is now accepted as an environmentally friendly and cost-effective advance with various biomedical applications. The cyanobacterium Synechocystis sp. is a unicellular spherical cyanobacterium with photo- and hetero-trophic capabilities. This study investigates the ability of this cyanobacterial species to produce silver nanoparticles (AgNPs) and the wound-healing properties of the produced nanoparticles in diabetic animals. Methods: UV–visible and FT-IR spectroscopy and and electron microscopy techniques investigated AgNPs’ producibility by Synechocystis sp. when supplemented with silver ion source. The produced AgNPs were evaluated for their antimicrobial, anti-oxidative, anti-inflammatory, and diabetic wound healing along with their angiogenesis potential. Results: The cyanobacterium biosynthesized spherical AgNPs with a diameter range of 10 to 35 nm. The produced AgNPs exhibited wound-healing properties verified with increased contraction percentage, tensile strength and hydroxyproline level in incision diabetic wounded animals. AgNPs treatment decreased epithelialization period, amplified the wound closure percentage, and elevated collagen, hydroxyproline and hexosamine contents, which improved angiogenesis factors’ contents (HIF-1α, TGF-β1 and VEGF) in excision wound models. AgNPs intensified catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities, and glutathione (GSH) and nitric oxide content and reduced malondialdehyde (MDA) level. IL-1β, IL-6, TNF-α, and NF-κB (the inflammatory mediators) were decreased with AgNPs’ topical application. Conclusion: Biosynthesized AgNPs via Synechocystis sp. exhibited antimicrobial, anti-oxidative, anti-inflammatory, and angiogenesis promoting effects in diabetic wounded animals.

The effects of temperature and light intensity on Microcystis aeruginosa PCC 7806 growth and mcyB transcripts (as a function of microcystin biosynthesis) were investigated at the logarithmic and stationary growth phases. The expression of the mcyB gene-one of the microcystin biosynthetic genes-under different treatments was quantified using real-time PCR. The results showed that cell number increased at 25°C with all light treatments. A significant positive correlation (P=0.060) between mcyB transcripts and cell number was found, indicating the presence of coupling between toxin biosynthesis and growth. The results also revealed that both temperature and growth phase were significantly correlated with the number of mcyB transcripts (P=0.005 and 0.036, respectively), with at least 67% of the variation attributable to these two factors alone. On the other hand, the effect of the range of light intensities tested was overly non-significant. Application of high light intensity, above saturation point for a prolonged period, was inhibitory to transcription of the mcyB gene. Maximum mcyB transcript number was attained during stationary phase of a Microcystis culture grown at 25°C under medium light intensity. The high level of mcyB transcription during stationary phase indicates an increase in the biosynthesis of microcystin. This possibly indicates the role of the toxin as an alarming chemical that cells would release upon lysis/death.

An investigation into the bioactive metabolites from a benthic, mat-forming strain dominating a polluted wastewater canal in Egypt was conducted. Phytochemical screening revealed the presence of saponins, flavonoids and alkaloids; vitamin C was also found at high concentrations. The isolate was investigated as a source of antimicrobial compounds. The lipophilic fraction was extracted using chloroform/methanol and bioassays for antimicrobial compounds were performed using strains of pathogenic bacteria. The fraction that showed the highest bioactivity was purified and its structure elucidated using UV, FTIR, proton-NMR and GC-MS. The compound's molecular weight was 220 and it was identified as butylated hydroxytoluene which has both antimicrobial and antioxidant activities. On the ecological front, this compound, and the other metabolites detected, seem to enable the isolate to dominate its niche and protect it from adverse conditions. On the commercial front, this compound is used as a food additive and was recently discovered in different cyanobacteria, and can be used as a lead compound for both drug and food industries to substitute for the expensive and hazardous synthetic analogs. Therefore, this strain can be considered as a potential source of bioactive compounds that should be further explored.

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