Characterisation of Streptomyces violascens OC125-8 lipase for oily wastewater treatment.

In this study, the lipase-producing bacterium Streptomyces violascens (GenBank number MF621564) was identified, and the extracellular S. violascens OC125-8 lipase produced by this strain was characterised for use in wastewater treatment. The lipase was partially purified by ammonium sulphate precipitation at a final yield of 3.28-fold purification and a recovery of 56%. The S. violascens OC125-8 lipase exhibited optimum catalytic activity at 40 °C and pH 8.0; it was stable at 30-40 °C with more than 86% residual activity after 1 h; it was also stable over a relatively broad pH range of pH 7.0-11.0, retaining 83.3-100% activity. V max and K m values were calculated as 0.61 µmol/min/mg and 0.259 mM, respectively. Enzyme activity significantly increased in the presence of Fe2+ ion but was inhibited by Ca2+, Mn2+, Cu2+ and Mg2+. The addition of a serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), strongly inhibited enzyme activity while ethylenediaminetetraacetic acid (EDTA), a metal chelating agent, had no inhibitory effect. The enzyme was fairly stable in the presence of surfactants as well as sodium perborate. Examination of commercial detergent tolerance revealed that the lipase was strongly stable in Tursil (88%), Pril (97%) and Fairy (98.5%), while the lipase was activated in Omo (113.4%) and Ariel (128.3%). Moreover, the lipase showed highest activity towards olive oil (100%), sunflower oil (90%) and burned sunflower oil (55%), while corn oil (44%) and burned olive oil (15%) were less hydrolysed by the enzyme. These properties demonstrate that S. violascens OC125-8 lipase is an ideal choice for oily wastewater management.

Ankaferd Blood Stopper with antibiofilm potential successfully inhibits the extracellular matrix degradation enzymes and promotes wound healing of 3T3 fibroblasts in vitro

Background/aim: The potential inhibitory effects of Ankaferd Blood Stopper (ABS) against biofilm formation of oral microorganisms and its capacity for collagenase, hyaluronidase, and elastase inhibitions that have important roles in wound healing have been investigated. Materials and methods: The wound healing potential was determined by its inhibition ability on collagenase, hyaluronidase, and elastase enzyme activities and was evaluated via scratch wound healing assay on murine 3T3 fibroblasts. The antibiofilm activity was tested against eight oral microorganisms using the crystal violet staining method. Results: At 10% ABS successfully inhibited the biofilm formation of the tested microorganisms. Enzyme inhibition analysis revealed that 3% ABS significantly inhibited all three enzymes related to wound healing. The scratch assay showed that wound closure was faster than that of the control for the 3% ABS/plate. Conclusion: The findings of the present study indicated that ABS has effective wound healing potential with its strong antibiofilm activity against oral cavity microorganisms.

The mutagenic, antimutagenic and antioxidant properties of Hypericum lydium.

CONTEXT: There is a growing market demand for Hypericum sp., a pharmacologically active plant that has been traditionally used to treat various ailments. However, there have been limited studies on the extract or essential oil of Hypericum lydium Boiss (Hypericaceae). OBJECTIVE: This study investigates for the first time the antioxidant, mutagenic and antimutagenic activity of an ethanol extract of H. lydium. MATERIAL AND METHODS: Ethanol extract from aerial parts of H. lydium harvested from Turkey were tested for this mutagenic and antimutagenic activities (2.0-0.002 mg/plate) using Ames Salmonella/microsome test system. 4-Nitro-o-phenylenediamine (4-NPD) (3 µg/plate) for the Salmonella typhimurium TA98 and sodium azide (NaN3) (8 µg/plate) for the S. typhimurium TA100 were used as positive controls. The antioxidant activity, total antioxidant activity and phenolic constituent of the extract (2.0-0.002 mg/mL) was determined by the inhibition of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ß-carotene-linoleic acid model and by means of Folin-Ciocalteu reagent, respectively. RESULTS: The extract showed no sign of mutagenicity at the tested concentrations (0.002-2.0 mg/mL), and showed concentration-dependent antimutagenic activity against NaN3 and 4-NPD ranging from 26.8 to 81.5%. The extract was found to be an efficient scavenger of DPPH (IC50 0.165 ± 0.23 mg/mL) and to inhibit ß-carotene-linoleic acid bleaching (IC50 0.39 ± 0.11 mg/mL). DISCUSSION AND CONCLUSION: These findings indicate ethanol extract of H. lydium to be a safe and effective agent that may be incorporated into new strategies for the prevention of cancer and mutagenesis.

New Lipase for Biodiesel Production: Partial Purification and Characterization of LipSB 25-4.

The lipolytic activities of 300 Streptomyces isolates were determined in Tributyrin and Rhodamine-B Agar. Lipase activities were also measured with p-nitrophenyl palmitate (p-NPP) as a substrate. The strain of Streptomyces bambergiensis OC 25-4 used in this study was selected among 300 strains of Streptomyces from MUCC as the best lipase producer. The incubation conditions were optimized and the inoculum amount, incubation period, effect of carbon and nitrogen sources, and rates of MgSO4 and CaCO3 were investigated. LipSB 25-4 (the lipase produced by S. bambergiensis OC 25-4 strain) was partially purified with ammonium sulphate precipitation, dialysis, and gel filtration chromatography 2.73-fold and with 92.12 U/mg specific activity. The optimal pH and temperature for LipSB 25-4 were determined as 8.0 and 50°C, respectively. The lipase has high stability in all pH and temperature values used in this study. While LipSB 25-4 was slightly activated in the presence of ß-mercaptoethanol, it was slightly reduced by PMSF. The enzyme conserved approximately 75% of its activity at the end of 60 h, in the presence of methanol and ethanol. Since LipSB 25-4 displays high activity in the thermophilic conditions and stability in the presence of organic solvents, this lipase can catalyse the biodiesel production from olive oil by the transesterification reactions.

Partial purification and characterization of the organic solvent-tolerant lipase produced by Pseudomonas fluorescens RB02-3 isolated from milk.

Eighty-five putative Pseudomonas isolates were obtained from various raw milk and pasteurized milk samples using Pseudomonas CFC agar. Among them, 36 isolates were identified as Pseudomonas fluorescens, and one isolate was identified as Pseudomonas putida. Lipase activity of the strains was quantitatively measured by the spectrophotometric method using p-nitrophenyl palmitate (p-NPP) as substrate. Detected lipase activity of the strains was between 10.03 U/mL and 22.16 U/mL. Pseudomonas fluorescens RB02-3 possessed the highest lipase activity. The extracellular lipase of P. fluorescens RB02-3 strain was homogeneously purified using a combination of ammonium sulfate precipitation, dialysis, and gel filtration column chromatography. This purification procedure resulted in 2.97-fold purification with 20.3% recovery. The enzyme was characterized, and exhibited maximum activity at pH 7.0 and 50 °C; after it was incubated for 1 h it was activated in the presence of hexane, ethyl acetate, isopropanol, and ethanol and remained stable after the incubation was extended for 2 hr. The lipase was slightly inhibited in the presence of Zn²+, Co²+, Cu²+, Ni²+ salts, and ethylenediamine tetraacetic acid (EDTA), whereas Cd²+, sodium dodecyl sulfate (SDS), and Tween-80 had no effect on its activity.