Bio-Characterization and Liquid Chromatography-Mass Spectrometry Analysis of Exopolysaccharides in Biofilm-Producing Cyanobacteria Isolated from Soil Crust: Exploring the Potential of Microalgal Biomolecules.

Exopolysaccharide-producing cyanobacterial strains in biological soil crusts are described, in addition to their chemical properties and antioxidant and flocculation activities. The EPSs from Pudukkottai blackish biological soil crusts (PBBSCs) showed significant amounts of total soluble proteins (0.1687 mg/mL) and carbohydrates (0.8056 mg/mL) compared with the Ariyalur blackish biological soil crusts (ABBSCs). LC-MS analysis of the cyanobacterial polysaccharides revealed the presence of natural sugars such as ribose and glucose/mannose, and uronic acids. The FTIR spectrum showed specific peak for OH and -NH stretching, C-H stretching, and carboxylic acids as the dominant groups in EPS. The in vitro DPPH assay of EPSs from PBBSCs showed 74.3% scavenging activity. Furthermore, the reducing power was determined to be 0.59 ata 500 mg/mL concentration, respectively. The extracted EPSs from the biological soil crust flocculated Kaolin clay suspension maximum at 500 mg/mL. Consequently, the cyanobacterial strain and exopolysaccharide characterization from the sacred forest's biological soil crust were analyzed for their bioactive potential, bio-crust diversity, and distribution.

Optimization Study of the Capacity of Chlorella vulgaris as a Potential Bio-Remediator for the Bio-Adsorption of Arsenic (III) from Aquatic Environments.

This study examined the ability of the green microalgae Chlorella vulgaris to remove arsenic from aqueous solutions. A series of studies was conducted to determine the optimal conditions for biological arsenic elimination, including biomass amount, incubation time, initial arsenic level, and pH values. At 76 min, pH 6, 50 mgL-1 metal concentration, and 1 gL-1 bio-adsorbent dosage, the maximum removal of arsenic from an aqueous solution was 93%. The uptake of As (III) ions by C. vulgaris reached an equilibrium at 76 min of bio-adsorption. The maximum adsorptive rate of arsenic (III) by C. vulgaris was 55 mg/gm. The Langmuir, Freundlich, and Dubinin-Radushkevich equations were used to fit the experimental data. The best theoretical isotherm of Langmuir, Freundlich, or/and Dubinin-Radushkevich for arsenic bio-adsorption by Chlorella vulgaris was determined. To choose the best theoretical isotherm, the coefficient of correlation was used. The data on absorption appeared to be linearly consistent with the Langmuir (qmax = 45 mgg-1; R2 = 0.9894), Freundlich (kf = 1.44; R2 = 0.7227), and Dubinin-Radushkevich (qD-R = 8.7 mg/g; R2 = 0.951) isotherms. The Langmuir and Dubinin-Radushkevich isotherms were both good two-parameter isotherms. In general, Langmuir was demonstrated to be the most accurate model for As (III) bio-adsorption on the bio-adsorbent. Maximum bio-adsorption values and a good correlation coefficient were observed for the first-order kinetic model, indicating that it was the best fitting model and significant in describing the arsenic (III) adsorption process. SEM micrographs of treated and untreated algal cells revealed that ions adsorbed on the algal cell's surface. A Fourier-transform infrared spectrophotometer (FTIR) was used to analyze the functional groups in algal cells, such as the carboxyl group, hydroxyl, amines, and amides, which aided in the bio-adsorption process. Thus, C. vulgaris has great potential and can be found in eco-friendly biomaterials capable of adsorbing arsenic contaminants from water sources.

Bioremoval capacity of Co+2 using Phormidium tenue and Chlorella vulgaris as biosorbents.

Microalgae sorbents are microalgae that have the potential to passively bind heavy metals/contaminants to their cellular structures in a process called biosorption. This study investigates the use of two species of microalgae to remove the toxic heavy metal cobalt from aqueous solution. Two microalgae isolates, Phormidium tenue and Chlorella vulgaris, were collected from the Wadi Hanifah Stream in Riyadh, the Kingdom of Saudi Arabia. We determined the capacity of both isolates to bioremove Co+2 ions and the optimum conditions under which this occurs. The two isolates were additionally characterized by microscopic and Fourier transform infrared spectroscopy (FTIR). In the current investigation, Phormidium tenue removed 94% of Co+2 under ideal conditions of pH 6, contact duration (30 min), starting concentration (50 mgL-1) and biosorbent dose (1gL-1); while Chlorella vulgaris removed 87% of Co+2 under the same parameters except pH 5.5 and contact duration (60 min). Fourier transform infrared spectroscopy (FTIR) confirms the binding of Co+2 to the biomass, which comprises many of the functional groups. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed some alterations to the shape of algal cells and cellular components for both microalgae studied. In addition, equilibrium study by both Langmuir and Freundlich models was performed to detect the effect of certain equilibrium factors on the capacity of the biosorption mechanism. Finally, Phormidium tenue and Chlorella vulgaris were discovered to be promising microalgae for effective cobalt biosorption in aquatic conditions.

Antimicrobial efficacy of Nocardiopsis sp. MK_MSt033 against selected multidrug resistant clinical microbial pathogens.

BACKGROUND: Actinomycetes show an active role in microbial disease control and antimicrobial metabolism production and were shown the greatest potentialities as sources of antimicrobial agents. The past few decades, an extensive literature has accumulated on the production of bioactive compounds from actinomycetes, particularily genus Streptomyces. METHODS: The actinomycetes were isolated with starch casein nitrate (SCN) agar medium. The prospective isolate was subjected to antimicrobial metabolites production. Further, the bio-extract was evaluated their biological properites by agar well diffusion assay and finally the extract was anaylized through GC-MS. RESULTS: In the present study, isolated 9 actinomycetes and the isolates were examined for their antifungal activities. Of these nine isolates, the isolate MK_MSt033 picked out from the rest, hences, it showed significant control towards the selected microbial pathogens. The prospective strain MK_MSt033 was determined as Nocardiopsis sp. The strain displayed effective antimicrobial activities against both bacterial and fungal pathgoens such as Escherichia coli, Staphylococcus aureus, Pencillium sp., and Aspergillus flavus respectively. Subsequently the chemical nature of the compounds produced by the potential isolate MK_MSt033 and it was successfully determined by GC-MS and it were 18 compounds with different retention time. CONCLUSION: The identified isolate Nocardiopsis sp. MK_MSt033 exhibited potential antimicrobial activities against selected microbial pathogens. Thus, the soil inhabiting Nocardiopsis sp. has explored for pharmaceutically active compounds with promising medical applications.

Eco-friendly synthesis of silver nanoparticles by Bacillus subtilis and their antibacterial activity.

Bacillus subtilis was used for biogenic of silver nanoparticles. Characterization of the prepared silver nanoparticles was done by UV-Vis spectroscopy, Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FT-IR). The particle size of the prepared nanoparticles ranges from 3 to 20 nm with spherical or roughly spherical forms. The antimicrobial efficacy of the produced nanoparticles was investigated against five strains of multidrug resistant microorganisms including: Staphylococcus aureus (MRSA), Staphylococcu s epidermidis, Klebsiella. pneumoniae, Escherichia coli and Candida albicans tested as yeast. During this study, the minimum inhibitory concentrations (MICs) and the minimum lethal concentrations (MLCs) of synthesized silver nanoparticles were detected using selected strains of the genus Bacillus by a broth dilution method. The rate of MIC of the prepared silver nano-particles versus the investigated clinical isolates exhibit a massive anti-microbial efficacy; (230 µgml-1) for MRSA; 180 for Staphylococcus epidermidis, 200 for Escherichia coli and 100 µgml-1 for Candida albicans. On the other hand, the lowest anti-microbial efficacy (300 µgml-1) was appeared for Klebsiella pneumonia. The obtained results demonstrated the effectiveness of the biogenic nanoparticles and the possibility of using them as a new method in combating infectious diseases.