Turbinaria ornata mediated silver nanoparticles (TOAg-NPs) were evaluated for antibacterial activity against 15 biofilm forming bacterial isolates. A field study in natural seawater for 60days showed antifouling activity of TOAg-NPs on stainless steel coupons (SS-304) coated with Apcomin zinc chrome (AZC) primer. Though TOAg-NPs showed broad spectrum of antibacterial activity, the maximum zone of inhibition was with Escherichia coli (71.9%) and a minimum with Micrococcus sp. (40%) due to the EPS secretion from Gram-positive bacteria. Compared to control coupons (18.9 [×103], 67.0 [×103], 13.5 [×104] and 24.7 [×104]CFU/cm2), experimental biocide coupons (71.0 [×102], 32.0 [×103], 82.0 [×103] and 11.3 [×104]CFU/cm2) displayed lesser bacterial population density. Toxicity studies revealed 100% mortality for Balanus amphitrite larvae at 250μgml−1 concentration within 24h, while 56.6% recorded for Artemia marina at the same concentration indicating less toxicity to non target species. It proved that AZC+TOAg-NPs prevent biofouling by its Ag-NS affinity and antimicrobial effectivity.

The aim of this study was to evaluate bacterial and fungal aerosol concentrations at the holy mosque (Al-Masjid Al-Haram). Air samples were collected from different locations inside and outside the holy mosque, during the month of Ramadan-2011 (the fasting month), using a portable Air-port MD8 gelatin filter sampler. Trypticase soya agar and Capek's dox agar media were used to count bacteria and fungi, respectively. The mean concentrations of airborne bacteria and fungi ranged between 105–106 colony forming unit per cubic meter of air (CFU/m3) outside, and ∼102–105 CFU/m3 inside locations. The highest outside bacterial concentrations 106 CFU/m3 were found at the Al Umra, Al Fatah and eastern plazas, and the highest inside fungal concentrations ∼105 CFU/m3 were found at the courtyard, expansion of 1st floor, and roof. Significant differences (P < 0.05) were found between bacterial and fungal concentrations inside and outside sampling locations, higher concentrations shifted towards to outside locations. Significant differences were also found between the bacterial and fungal concentrations inside–unclosed and semi-closed (P < 0.05) with inside-closed locations. Gram-positive bacteria, Bacillus and Micrococcus, and fungi, Aspergillus niger were the dominant microbial aerosol genera. The obtained data is considered a step to make up the gap about airborne microbial contamination inside the holy mosque, and microbial air quality should be studied along over the year at the holy mosque in the future.

Bacterial strains and metagenomic clones, both obtained from petroleum reservoirs, were evaluated for petroleum degradation abilities either individually or in pools using seawater microcosms for 21days. Gas Chromatography–Flame Ionization Detector (GC–FID) and Gas Chromatography-Mass Spectrometry (GC–MS) analyses were carried out to evaluate crude oil degradation. The results showed that metagenomic clones 1A and 2B were able to biodegrade n-alkanes (C14 to C33) and isoprenoids (phytane and pristane), with rates ranging from 31% to 47%, respectively. The bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 showed higher rates reaching 99% after 21days. The metagenomic clone pool biodegraded these compounds at rates ranging from 11% to 45%. Regarding aromatic compound biodegradation, metagenomic clones 2B and 10A were able to biodegrade up to 94% of phenanthrene and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 55% to 70% after 21days, while the bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 were able to biodegrade 63% and up to 99% of phenanthrene, respectively, and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 23% to 99% after 21days. In this work, isolated strains as well as metagenomic clones were capable of degrading several petroleum compounds, revealing an innovative strategy and a great potential for further biotechnological and bioremediation applications.

Oil-degrading bacteria were isolated from waters and sediments of the Manila Bay and Pasig River [Philippines]. Five types of bacteria were isolated from Manila Bay and four from Pasig River. The identified crude oil degrading species are Vibrio sp., Alcaligenes sp., Flavobacterium indologenes and Acinetobacter sp. from Manila Bay, and Pseudomonas aeruginosa, Bacillus sp., Micrococcus sp. and Pseudomonas putida from Pasig River. These isolates were identified through morphological and physiological characterization. The bioremediation potential for each of the isolates was assessed. The percentages oil conversion for the bacterial isolates ranged from 2.99 percent - 53.44 percent in one week's time. Alcaligenes sp. exhibited the highest biodegradation potential for all isolates. Statistical analysis revealed that the mean percentages diesel oil conversion by the isolates were significantly higher than their mean percentages crude oil conversion. Pure and mixed cultures did not give significant differences in their mean percentages crude oil conversion

Levofloxacin (LFX) is a widely used antibiotic medication. Persistent traces of LFX in water and wastewater may induce bacterial resistance. Photon-driven advanced oxidation processes (AOPs) can assist in attaining complete abatement of LFX for environmental protection. This work benchmarks different solar AOPs based on hydroxyl radical (OH•) and sulphate radical (SO₄•⁻) chemistry. Other oxidant precursors, as radical sources, were used to selectively control the generation of either hydroxyl radical (i.e., H₂O₂), sulphate radical (i.e., peroxydisulphate (PDS)), or a controlled mixture ratio of both OH•/SO₄•⁻ (i.e., peroxymonosulphate (PMS)). The influence of pH on degradation performance was evaluated using unbuffered and buffered solutions. Simulated irradiation/PMS process exhibited a strong pH-dependence attaining partial degradation of ca. 56% at pH 5 up to complete degradation at pH 7. Despite the similitudes on the abatement of target pollutant LFX in pristine solutions, only simulated irradiation/PDS treatment achieved effective abatement of LFX in wastewater samples given the higher selectivity of SO₄•⁻. Toxicity tests were conducted with Escherichia coli (LMG2092) and Micrococcus flavus (DSM1790), demonstrating successful inhibition of the antibiotic character of polluted waters, which would contribute to preventing the development of resistant bacterial strains. Finally, a degradative pathway was suggested from the by-products and intermediates identified by LC–MS. Results demonstrate that the degradation of specific functional groups (i.e., piperazine ring) is associated with the loss of antibacterial character of the molecule.

Soil microbial communities play an important role in the biodegradation of different petroleum derivates, including hydrocarbons. Also other biological factors such as enzyme and respiration activities and microbial abundance are sensitive to contamination with petroleum derivates. The aim of this study was to evaluate the response of autochthonic microbial community and biological parameters (respiration, dehydrogenase and catalase activities, total microorganisms count) on contamination with car fuels and engine oils. The surface layer (0–20 cm) of Mollic Gleysol was used for the experiment. In laboratory conditions, soil was contaminated with the following petroleum substances: car fuels (petrol, diesel) and car engine oils (new and waste—after 10,000 km). The results demonstrated that, among the investigated hydrocarbon substances, petrol addition seemed to be the most toxic for the microbial activity of the investigated soil. The toxicity of the used hydrocarbon substances to microorganisms might be summarized as follows: diesel > new oil > waste oil > petrol. Species belonging to the genera Micrococcus and Rhodococcus were noted as the major autochthonic bacteria being present in soil contaminated with new automobile oil, whereas species of the genera Bacillus sp. and Paenibacillus sp. were identified in the combination treated with waste oil.

A great deal of research has been directed towards the problem of reduction and control of volatile organic compounds (VOCs). The aim of this research is to find a process that is both efficient and inexpensive in comparison with traditional air treatment technologies.Our biofilter (one stage system, 2 m in height) is an aerobic system for waste gases containing VOCs using the degradation properties of microbial flora (assorted cultures of Bacillus, Micrococcus, Acinetobacter and yeast). In this process, polluted gas diffuses across a filter bed into which a microbial culture has previously been introduced. Peat is the medium of choice for inoculation with microorganisms because of its adsorption and absorption properties, ability to retain moisture, and buffering capacity. Furthermore, the peat utilized is spherical in shape; thus, it is possible to avoid problems related to compacting.The objective of this study was to eliminate VOCs emitted from a rotogravure process. We were able to achieve promising results from biofiltration of two types of VOCs (a mixed solvent containing isopropyl acetate and 1-nitropropane, and the solvent: 1-nitropropane). The results obtained indicate that the elimination of nitropropane and the mixed solvent in the biofilter are considered to follow zero-order kinetics with reaction rate limitation and diffusion rate limitation, respectively.

This study examined the performance of the chitosan-immobilized cadmium-resistant bacteria Arthrobacter sp. and Micrococcus sp. on cadmium phytoremediation by Chlorophytum laxum in cadmium-polluted soil. These immobilized cadmium-resistant bacteria can survive in cadmium-contaminated soil and significantly increased soil cadmium solubility, but the ability of chitosan-immobilized cells to increase cadmium solubility was lower than that of free cells. A pot experiment demonstrated that chitosan-immobilized Micrococcus sp. promoted the growth of C. laxum planted in cadmium-contaminated soil. A significant increase in the cadmium concentration in the roots and aboveground parts of C. laxum was found in plants inoculated with free and chitosan-immobilized cells of these bacteria. The performance of Arthrobacter sp. free cells to augment cadmium accumulation in C. laxum was a little bit better than that of chitosan-immobilized Arthrobacter sp., except at 9 weeks after planting. The phytoextraction coefficient, bioaccumulation factor, and translocation factor of C. laxum inoculated with free and chitosan-immobilized cells of cadmium-resistant bacteria were higher than those of the uninoculated control and increased with time. Our findings suggest that chitosan-immobilized cells can be exploited to enhance the efficiency of cadmium phytoremediation by C. laxum.

Brown mud is a waste by-product of alumina production by Bayer process. Due to extensive sodium hydroxide use in the process, brown mud disposal site near Ziar nad Hronom (Banska Bystrica region, Slovakia) and drainage water are ones of the greatest environmental burdens in Slovakia. Drainage water from this landfills has pH value higher than 13, and it contains many heavy metals and elevated salt content. In our experiments, relatively numerous bacterial population was detected in the drainage water with frequency of about 80 cfu/ml using cultivation approach. The alkalitolerant heterotrophic isolates were identified by combination of MALDI-TOF and 16S rDNA analysis. Drainage water population was dominated by Actinobacteria (Microbacterium spp. and Micrococcus spp.) followed by low G + C-content gram-positive bacteria (Bacillus spp.). Two isolates belonged to gram-negative bacteria only, identified as Brevundimonas spp. Phylogenetic and biochemical analyses indicate that nearly half of the bacteria isolated are probably representatives of a new species. Brown mud disposal site is proposed as a source of new bacterial taxa possibly used in bioremediation processes.

Bioaerosol concentration was measured in wastewater treatment units in south of Tehran, the largest wastewater treatment plant in the Middle East. Active sampling was carried out around four operational units and a point as background. The results showed that the aeration tank with an average of 1016 CFU/m³ in winter and 1973 CFU/m³ in summer had the greatest effect on emission of bacterial bioaerosols. In addition, primary treatment had the highest impact on fungal emission. Among the bacteria, Micrococcus spp. showed the widest emission in the winter, and Bacillus spp. was dominant in summer. Furthermore, fungi such as Penicillium spp. and Cladosporium spp. were the dominant types in the seasons. Overall, significant relationship was observed between meteorological parameters and the concentration of bacterial and fungal aerosols.