Potential Biosurfactant-producing Bacteria from Pharmaceutical Wastewater using Simple Screening Methods in South-West, Nigeria

Emerging multiple opportunities for industrial production and environmental applications have focused increasing research attention on biosurfactants in recent years. Hydrocarbon-polluted soils have proved a major source of biosurfactant-producing bacteria. In this study an alternative method of producing biosurfactants was established, based on pharmaceutical effluents. Pharmaceutical effluents are a rich source of complex organic compounds with potential as a substrate for microbial biosurfactant production. A successful biosurfactant screening assay is achieved when a combination of different methods are employed. Biosurfactant producing bacteria were isolated from pharmaceutical effluent and identified by biochemical methods. The best biosurfactant producer was identified by a molecular method. The biosurfactant screening techniques employed were drop collapse assay, haemolytic assay, oil spreading assay, bacteria adhesion to hydrocarbon assay and emulsification assay. Analysis of haemolytic activity indicated that 35 isolates (44.30 %) produced beta-haemolysis, 12 isolates (15.19 %) produced gamma-haemolysis, while 32 isolates (40.51 %) produced alpha-haemolysis. The highest zone of clearance was 42.0±1.73 by isolate DF7 and lowest zone of clearance was obtained from isolate GC5 of 12.0±0.73. Screening of the 35 isolates using the oil spreading test showed that 28 isolates (80.0 %) were positive, while 7 isolates (20.0 %) were negative. The highest zone of clearance for the oil in water was 19.0±0.1 by DF1 while the lowest zone was 4.3±0.33 by MB3. The drop collapse test revealed that 22 isolates (78.57 %) were positive and 6 isolates (21.43 %) were negative. At 0 h, the highest emulsification percentage was 74.4 % by Bacillus licheniformis and the lowest was 42.5 % by Arthrobacter globiformis. After 24h, the highest emulsification value (69.23 %) was obtained for Bacillus clausis, while the lowest value (30.84 %) was obtained for Arthrobacter globiformis. The findings demonstrated the ability of the isolates to produce biosurfactant, and confirmed the capacity of Bacillus clausis isolated from pharmaceutical effluents as a potential bacteria for biosurfactant production

A focus on biometal systems of some phyto-antibiotic drug complexes

Biometal coordination bearing active donor atoms of medicinal plant extracts or herbal isolates (phytochemicals) in the recent approach of biomedical sciences is a new and advanced chemotherapeutics for combating antibiotics resistance. Stereochemistry of central metal ions around active plant molecules can give rise to robust solid state 3D metal complexes of antibiotics aiding better biological performance/affinity without any side effect compared with the parent biomolecules (organic ligands). This review therefore focuses on the applications of medicinal plant extracts as antibiotics. Structural systems of metal complexes of flavonoids, curcumins, alkaloids, carotenoids and coumarins from aloe vera, acalypha and henna leaf (AAH) are also described with a view to achieving the rationale for functional bioactive antibiotic drug

Regeneration of a deactivated surface functionalised polyacrylonitrile supported Fenton catalyst for use in wastewater treatment

open access journalSuccessful attempts to regenerate a used surface functionalised nanocoated polyacrylonitrile (PAN) catalyst are described here. During use in wastewater treatment, the novel Fenton catalyst (F1) is deactivated due to iron loss caused by acid hydrolysis. In this study the deactivated catalyst (D1) is subjected to reactions with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC), followed by reactions with either hydroxylamine to give sample T1 or hydroxylamine and hydrazine to give sample T2. The samples were then impregnated with iron(III) salt to give either Fe-T1 or Fe-T2. The catalysts were characterized by Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), Atomic Absorption (AA) and UV/VIS spectroscopies, Scanning Electron Microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy and Electron Spin Resonance (ESR) spectroscopy. The iron on the regenerated catalyst was found to be in complexed form but had deposited iron oxide species as well. The catalysts were tested in batch mode and compared with the fresh modified PAN catalyst in the degradation of the dye Reactive Orange 16 (RO-16) with analysis by UV/VIS spectroscopy. The reactivated catalysts prepared with EDC were found to be more active and faster (as measured at 120 min) in decolourising RO-16 than the fresh catalytic mesh but also with a higher degree of Fe leaching (0.85% loss of iron per gram of Fe-T2 catalyst over 6 cycles compared to 0.32% loss of Fe per gram of F1 catalyst over 6 cycles). This leaching was found not to contribute significantly to degradation of the dye and the preliminary results suggest that the regime can be used for catalyst regeneration encouraging industrial uptake

Iron(III) and copper(II) complexes bearing 8-quinolinol with amino-acids mixed ligands: Synthesis, characterization and antibacterial investigation

AbstractFour d-orbital metal complexes with mixed ligands derived from 8-hydroxyquinoline (HQ) and amino acids (AA): l-alanine and methionine have been synthesized through a mild reflux in alkaline solution and characterized by elemental analyses, infrared, electronic transition, and temperature dependant magnetic susceptibility. The IR spectroscopy revealed that iron and copper ions coordinated through carbonyl (CO), hydroxyl group (OH) of the amino acids, N-pyridine ring of hydroxyquinoline. The elemental analysis measurement with other obtained data suggested an octahedral geometry for the iron(III) complexes and tetrahedral geometry for the copper(II) complexes. From the molar magnetic susceptibility measurement, the iron(III) system (S=5/2) d5 (non-degenerate 6A1) with χmT=0.38cm3Kmol−1 showed an antiferromagnetic while Cu2+ ions system (S=½) (2T2g) has χmT=4.77cm3Kmol−1 described as paramagnetic behaviour. In vitro antimicrobial investigations of the metal complexes against standard bacteria species gave significant inhibition with, copper complex showing highest inhibitions against Pseudomonas aeruginosa (ATCC27853) of 43mm at 10μg/ml signalling its potential as pharmaceutical or chemotherapeutic agents