Heterologous expression, purification, and characterization of thermo- and alkali-tolerant laccase-like multicopper oxidase from Bacillus mojavensis TH309 and determination of its antibiotic removal potential.

Laccases or laccase-like multicopper oxidases have great potential in bioremediation to oxidase phenolic or non-phenolic substrates. However, their inability to maintain stability in harsh environmental conditions and against non-substrate compounds is one of the main reasons for their limited use. The gene (mco) encoding multicopper oxidase from Bacillus mojavensis TH309 were cloned into pET14b( +), expressed in Escherichia coli, and purified as histidine tagged enzyme (BmLMCO). The molecular weight of the enzyme was about 60 kDa. The enzyme exhibited laccase-like activity toward 2,6-dimethoxyphenol (2,6-DMP), syringaldazine (SGZ), and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The highest enzyme activity was recorded at 80 °C and pH 8. BmLMCO showed a half-life of ~ 305, 99, 50, 46, 36, and 20 min at 40, 50, 60, 70, 80, and 90 °C, respectively. It retained more than 60% of its activity after pre-incubation in the range of pH 5-12 for 60 min. The enzyme activity significantly increased in the presence of 1 mM of Cu2+. Moreover, BmLMCO tolerated various chemicals and showed excellent compatibility with organic solvents. The Michaelis constant (Km) and the maximum velocity (Vmax) values of BmLMCO were 0.98 mM and 93.45 µmol/min, respectively, with 2,6-DMP as the substrate. BmLMCO reduced the antibacterial activity of cefprozil, gentamycin, and erythromycin by 72.3 ± 1.5%, 79.6 ± 6.4%, and 19.7 ± 4.1%, respectively. This is the first revealing shows the recombinant production of laccase-like multicopper oxidase from any B. mojavensis strains, its biochemical properties, and potential for use in bioremediation.

Anticancer potential of Origanum munzurense extract against MCF-7 breast cancer cell.

Origanum munzurense (O. munzurense) is an endemic species of Tunceli region of Turkey. In this study, we investigated in vitro anticancer effect of aqueous extract of O. munzurense (OME) on breast cancer cells (MCF-7). In vitro cytotoxic effect of OME was evaluated in MCF-7 cells by MTT assay. The wound-healing assay was used to examine the inhibition of migration. Annexin V/propidium iodide staining, cell-cycle distribution was assessed by flow cytometry for MCF-7 cells treated with OME. MTT results show that OME demonstrated in vitro cytotoxicity with 600 mg at 48 h on MCF-7. Doses of 400 µg/mL and 600 µg/mL OME significantly suppressed the migration rate of MCF-7 cells. OME significantly decreased the percentage of live cancer cells and showed an apoptotic effect after 48 h of incubation. These results show that OME is effective against breast cancer when administered at high doses and for a long time.

Antimicrobial, antibiofilm, and anticancer potential of silver nanoparticles synthesized using pigment-producing Micromonospora sp. SH121.

Silver nanoparticles (AgNPs) have gained interest as an alternative pharmaceutical agent because of antimicrobial resistance and drug toxicity. Considering the increasing request, eco-friendly, sustainable, and cost-effective synthesis of versatile AgNPs has become necessary. In this study, green-made AgNPs were successfully synthesized using Micromonospora sp. SH121 (Mm-AgNPs). Synthesis was verified by surface plasmon resonance (SPR) peak at 402 nm wavelength in the UV-Visible (UV-Vis) absorption spectrum. Scanning electron microscopy (SEM) analysis depicted that Mm-AgNPs were in the size range of 10-30 nm and spherical. Fourier transform infrared spectroscopy (FTIR) confirmed the existence of bioactive molecules on the surface of nanoparticles. The X-ray diffraction (XRD) analysis revealed the face-centered cubic (fcc) structure of the Mm-AgNPs. Their polydispersity index (PDI) and zeta potential were 0. 284 and -35.3 mV, respectively. Mm-AgNPs (4-32 µg/mL) exhibited strong antimicrobial activity against Bacillus cereus, Enterococcus faecalis, Enterococcus hirae, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas putida, Staphylococcus epidermidis, Streptococcus pneumoniae, and Aspergillus flavus. Mm-AgNPs partially inhibited the biofilm formation in Acinetobacter baumannii, E. coli, K. pneumoniae, and Pseudomonas aeruginosa. Furthermore, results showed that low concentrations of Mm-AgNPs (1 and 10 µg/mL) caused higher cytotoxicity and apoptosis in DU 145 cells than human fibroblast cells. Based on the results, Mm-AgNPs have an excellent potential for treating infectious diseases and prostate cancer.

Pine needle and semi-permeable membrane device derived organochlorine compounds (OCPs) concentrations in air in Mersin Province to Taurus, Turkey.

Organochlorine pesticides (OCPs) were analyzed in three different ages (half-, 1.5-, 2.5-year-old) for needles and semi permeable membrane devices (SPMDs) at three deployment periods from sea level to 1881 meter above sea level. Individual HCHs concentrations ranged between 1.4 and 129 pg/g fw depending on the age and sampling season while 2.5-year-old needles showed higher HCHs levels compared to half and 1.5- year-old. Correlation between elevation and HCH concentration in SPMDs was found but not in needle samples. Concentrations of HCHs in SPMDs indicated clearly cold condensation effect on accumulation in winter period and increased with altitude. Concentrations of DDTs in half and 1.5-year-old needles were lower than 2.5-year-old needles. The highest total concentration of DDTs was detected in 1-year-period SPMD. Higher concentrations were found in 2.5-year-old needles for other OCPs. Seasonal and altitude-dependent changes were not observed for other OCPs in SMPDs. Total accumulation of OCPs in SPMDs were found higher than in needles. On the contrary, an increased accumulation rate was observed for HCHs in SPMD. In general, Total concentrations of DDTs and HCHs were similar to total of other OCPs in all altitudes when dominating endosulfan wasnot taken into account in the computation of total concentration of other OCPs.

Polycyclic aromatic hydrocarbons (PAHs) determined by pine needles and semipermeable membrane devices along an altitude profile in Taurus Mountains, Turkey.

Polycyclic aromatic hydrocarbons (PAHs) were analyzed at different altitudes of Taurus Mountains in semipermeable membrane devices (SPMD) and in half-, one-and-a-half-, and two-and-a-half-year-old pine needles. SPMDs were deployed for three different exposure periods: March to September (Summer), September to March (Winter), and March to March (whole year) at eight sites where needle samples were collected. The values of PAHs in needles were between 4.4 to 6066 pg g/fw in half-year-old, 7.2 to 111,115 pg g/fw in 1.5-year-old, and 9.7 to 85,335 pg g/fw in 2.5-year-old needles. Mass of PAHs collected by SPMDs varied from

Evaluation of organochlorine pesticides in breast milk samples in Turkey applying features of the partial order technique.

Exposure data to organochlorine pesticides (OCPs) of mothers' breast milk samples were measured in different locations in the Taurus Mountains/Turkey. Villages at five altitudes were looked upon. The data analysis method applied is the Hasse diagram technique, based on Discrete Mathematics. For each of the five regions, one Hasse diagram was calculated and showed the same maximal object, namely, p-p'-Dichlorodiphenyldichloroethane (DDE). In a further data investigation step, we performed the similarity analyses of the locations in order to quantify the similarities and incomparabilities. It was revealed that no correlation exists between most altitudes and the pattern of contamination of breast milk samples. The two lowest situated areas, Sahil at sea level and Ciftlikköy at 121 m above sea level were similar. We reduced the datasets by applying the interval analysis followed by similarity analyses. We observed that endrin (END1), mirex (MIRE), and pentachlorobenzene (PECB) reduce most severely the similarity.

Analysis of human milk to assess exposure to PAHs, PCBs and organochlorine pesticides in the vicinity Mediterranean city Mersin, Turkey.

Assessment of human exposure to environmental persistent organic pollutants such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) based on the levels in human breast milk provides a reasonable tool not only to assess the contaminant burden in mothers but also to assess potential exposure of breast-fed neonates. There are limited data on levels of PCBs and OCPs in humans but no previous reports from Turkey on chemically determined levels PAHs in human milk. The aim of this study was to report the levels and accumulation profiles of OCPs, PCBs and PAHs in 47 breast milk samples obtained from a Mediterranean city, Mersin. High resolution analyses were performed by a gas chromatography coupled with mass spectrometer (GC-MS). Dichlorodiphenyldichloroethane (4.4'-DDE) was the dominant pollutant. Beta-hexachlorocyclohexane (ß-HCH), dichlorodiphenyltrichloroethane (4.4'-DDT), dieldrin, hexachlorobenzene, oxy-chlordane, cis-heptachlorepoxide were the other main OCPs detected. Mean levels of ΣPCB congeners and WHO(PCB)-TEQ were 9.94 and 0.001 ng/g lipid, respectively. PCB 153 showed the highest concentration (3.37 ng/g lipid), followed by PCB 138 and 180. For the dioxin-like PCBs, PCB 118 was the dominant (0.97 ng/g lipid). Naphthalene, phenanthrene, pyrene and fluoranthene were the major PAHs among the 16 PAHs detected. The estimated daily intakes of DDTs, PCBs, HCHs and HCB were not exceeded the tolerable daily intake (TDI) proposed by the Health Canada Guideline. These results indicate that the neonates of Mersin city are exposed to persistent organic pollutants analyzed in this study. However, neonates born in Mersin province are less exposed than the ones born in other regions, considering OCP and PCB levels in breast milk.

The occurrence and environmental effect of persistent organic pollutants (POPs) in Taurus Mountains soils.

PURPOSE: Persistent organic pollutants (POPs) are of global concern due to their ubiquitous presence and toxicity. The occurence of polychlorinated dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), co-planar biphenyls (PCBs), hexachlorocyclohexanes (HCH), dichlorodiphenyltrichloroethanes (DDT), and organochlorine pesticides (OCPs) in forest soil collected from Taurus mountains may have adverse effects on the environment and health. The aim of the study was to investigate the outcome and distribution of POPs in the environment and the possible grasshopper effect along an altitude transect from sea level up to nearly 2,000 m a.s.l at a spatial distance of about 60 km in the southeastern Turkish Mediterranean Sea. METHODS: The samples were collected at a height of 121, 408, 981, 1,225, 1,373, 1,639, and 1,881 m above sea level from Taurus Mountains, Turkey. The results were confirmed using high-resolution gas chromatography-high-resolution mass spectrometry. RESULTS: The levels of the PCDD in forest soil from Taurus Mountains varied from nearly 4 to 12 pg g(-1) dry weight (dw). PCDF concentrations ranged from 2 to 7 pg g(-1) dw. Considerably high DDT levels detected in five stations indicated (3,223-24,564 pg g(-1)) its extensive local application or atmospheric transport. PCB levels were determined between 80 and 288 pg g(-1) dw. HCH concentrations ranged from 141 to 1,513 pg g(-1) dw. The other OCP was between 102 and 731 pg g(-1). CONCLUSION: Although the use of POPs has been banned, our results show that they could still be found in Turkey. Their presence may be attributed to the degradation of pesticides which are newly banned and, as well as to the atmospheric migration and deposition. The lattitude of sampling sites, the chemical, and physical parameters of soil have observed no effect on the fate of POPs in the environment.

Oxidative stress response in Nile tilapia (Oreochromis niloticus) exposed to textile mill effluent.

Textile mill effluent is an important pollution factor because of its organic and inorganic substances content. In this study, toxic effects of textile mill effluent on fish Oreochromis niloticus were investigated by using antioxidant enzymes and lipid peroxidation (LPO) responses. Superoxide dismutase (SOD), catalase (CAT) enzyme activities and lipid peroxidation by means of thiobarbituric reactive substances (TBARS) level were measured in liver and gill tissues of fish. The fish were exposed to non-lethal concentrations (0.1%, 1% and 10%) of textile mill effluent for 15, 30 and 45 days. In control group, fish were left in aquariums containing tap water without chlorine. As a result, the activities of SOD, CAT enzymes and level of TBARS in the liver and gill increased in 15, 30 and 45 days after 1% and 10% doses application.

Antioxidant enzyme activity and lipid peroxidation in liver and gill tissues of Nile tilapia (Oreochromis niloticus) following in vivo exposure to domoic acid.

Domoic acid (DA) is a neurotoxicant produced by Pseudo-nitzschia from diatomeae. Although the neurotoxic and genotoxic effects of DA have been well documented, the number of in vivo studies regarding the oxidative stress inducing effects of DA is quite limited. In this study, in vivo toxic effects of DA were investigated on fish Oreochromis niloticus (Fam: Cichlidae), using oxidative stress biomarkers. Fish were exposed to three different concentrations (1, 5 and 10 microg/g body weight) of DA via intraperitoneal injections and the tissues were sampled at 24, 48 and 72 h post-treatment. Changes in the level of lipid peroxidation, and activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GRd) were evaluated in liver and gill tissues. Our results revealed dose and time dependent increases in the oxidative stress parameters. It was also observed that the toxic effects were more pronounced in liver than in gill tissue.

Evaluation of cytogenetic effects of lambda-cyhalothrin on Wistar rat bone marrow by gavage administration.

In this study, a synthetic pyrethroid insecticide, lambda-cyhalothrin (LCT), was administered to adult female albino rats (Wistar rats) by gavage dose of 6.12, 3.06, 0.8 mg/kg b.w. repeated for 13 days at 48 h intervals. The cytotoxic and genotoxic effects of LCT were investigated in bone marrow cells, using the structural chromosomal aberration (SCA) and micronucleus (MN) test systems. Mitomycin C (MMC) was also used as positive control (2mg/kg b.w.). All the doses of LCT increased the number of SCAs and the frequency of micronucleated erythrocytes, with respect to the control group. Only the highest dose of LCT significantly increased the MN frequency compared with control (P < 0.01). It was also observed that LCT caused a significant decrease in the number of polychromatic erythrocytes compared with controls (p < 0.001). These observations indicate the in vivo suspectibility of mammals to the genetic toxicity and cytotoxicity potential of LCT.

Induction of micronuclei by lambda-cyhalothrin in Wistar rat bone marrow and gut epithelial cells.

We have investigated the genotoxicity of lambda-cyhalothrin (LCT) (CAS registry No. 91465-08-06), a pyrethroid insecticide, in bone marrow cells and in colonic crypt epithelial cells of groups of four rats per dose treated in vivo by gavage at doses of 0.8, 3.06 and 6.12 mg/kg body weight (body wt). We measured genotoxicity using the micronucleus (MN) assay, scoring 2000 polychromatic erythrocytes (PCEs) per animal for bone marrow and 1000 colonic crypt epithelial cells per animal for the colon. We assessed cytotoxicity in bone marrow by calculating the ratio of PCEs to normochromatic erythrocytes, and in the colonic crypt epithelium by observing the frequency of binucleate cells and the mitotic index in 1000 cells. Apoptosis in colonic crypt epithelial cells was measured by observing the frequency of karyorrhexis and karyolysis in 1000 cells. We found that LCT induced a statistically significant dose-related increase in MN formation in the bone marrow and the colonic crypt. The colonic epithelium was more sensitive to the clastogenic effects of LCT than the bone marrow as judged by the significantly higher frequencies of MN in the colon than in the bone marrow at doses of 3.06 and 6.12 mg/kg body wt.

Cytogenetic effects of lambda-cyhalothrin on Wistar rat bone marrow.

In this study, the genotoxic and cytotoxic potential of lambda-cyhalothrin (LCT), a synthetic pyrethroid insecticide, was investigated in Wistar rat bone-marrow cells, using the structural chromosomal aberration (SCA) and micronucleus (MN) test systems. LCT was administrated to adult female albino rats as repeated i.p. doses of 6.12, 3.06, 0.8 mg/kg BW for 13 days at 48 h intervals. Mitomycin C (MMC) was used as a positive control (2 mg/kg BW). All the doses of LCT increased the number of structural chromosomal aberrations and the frequency of micronucleated erythrocytes, compared with the control group. It was also observed that LCT caused a significant decrease in the number of polychromatic erythrocytes. Our results demonstrate that LCT has a clastogenic/genotoxic potential as measured by the bone marrow SCA and MN tests in Wistar rats.