Oxidation-reduction Potential Levels Research Articles

Enhanced Succinic Acid Production and Electronic Utilization Efficiency by Actinobacillus succinogenes 130Z in an ORP-Controlled Microbial Electrolysis Cell System

Microbial electrochemical systems have shown great value as a means of enhancing the efficiency of fermentation reactions, but at present, there is no reliable means to balance the extracellular electron supply and corresponding intracellular demands in these systems. The current work describes the unique use of an oxidation–reduction-potential (ORP)-level-controlled microbial electrolysis cell (MEC) system to successfully balance the extracellular electron supply and succinic acid fermentation via A. succinogenes (130Z). The ORP-controlled MEC system with neutral red (NR) yielded a significant increase in succinic acid production (17.21%). The utilization of NR in this MEC system improved the ORP regulatory sensitivity. The optimal approach to the ORP level control was the use of a −400 mV high-voltage electric pulse-based strategy, which increased the yield of succinic acid by 13.08% compared to the control group, and reduced the energy consumption to 52.29% compared to the potentiostatic method. When compared to the −1 V constant potential MEC system, the high-voltage electric pulse-based ORP strategy for the MEC system control provided sufficient electrons to this system while using less electricity (11.96%) and producing 12.48% (74.43 g/L) more succinic acid during fed-batch fermentation. The electronic utilization efficiency of the ORP-controlled MEC system was 192.02%, which was 15.19 times that of the potentiostatic system. The electronic utilization efficiency is significantly increased in the ORP-controlled MEC system. Succinic acid production is ensured by a high-voltage electric pulse-based method, while the influence on cell growth and power consumption are minimized. Fed-batch fermentation with the high-voltage electric pulse-based ORP strategy for MEC system control is noted to be ideal to achieve a further increase in succinic acid concentration and electronic utilization efficiency.

Improving soil aquifer treatment efficiency using air injection into the subsurface

Abstract. Soil aquifer treatment (SAT) is an effective and sustainable technology for wastewater or stormwater treatment, storage, and reuse. During SAT, the vadose zone acts as a pseudo-reactor in which physical and biochemical processes are utilized to improve the infiltrated-water quality. Dissolved oxygen (DO) is necessary for aerobic microbial oxidation of carbon and nitrogen species in the effluent. Therefore, to enhance aeration, SAT is generally operated in flooding and drying cycles. While long drying periods (DPs) lead to better oxidizing conditions and improve water quality, they reduce recharge volumes. As the population grows, the quantity of effluent directed to SAT sites increases, and increasing recharge volumes become a concern and often a limiting factor for SAT usage. In this study, direct subsurface air injection SAT (Air-SAT) was tested as an alternative to long-DP operation. Six long-column experiments were conducted (2 m column) that aimed to examine the effect of air injection on the soil's water content, oxidation–reduction potential (ORP), DO concentrations, infiltrated amounts, and ultimate outflow quality. In addition to basic parameters, such as dissolved organic C (DOC) and N species, the effluent quality analysis also included an examination of three emerging water contaminants: ibuprofen, carbamazepine, and 1H-benzotriazole. Pulsed-air-injection experiments were conducted during continuous flooding using different operation modes (i.e., air pulse durations, frequencies, and airflow rates). Our results show that Air-SAT operation doubled the time during which infiltration was possible (i.e., the infiltration was continuous with no downtime) and allowed up to a 46 % higher mean infiltration rate in some cases. As a result, the infiltration volumes in the Air-SAT modes were 47 %–203 % higher than conventional flooding–drying operation (FDO). A longer air pulse duration (60 min vs. 8 min) and higher airflow rate (∼2 L min−1 vs. ∼1 L min−1) led to a higher mean infiltration rate, whereas a high pulse frequency (4.5 h−1) led to a lower mean infiltration rate compared with low-frequency operation (24 h−1). Air injection also allowed good recovery of the ORP and DO levels in the soil, especially in the high-frequency Air-SAT experiments, where steady aerobic conditions were maintained during most of the flooding. Consequently, the mean DOC, total Kjeldahl N (TKN), and ibuprofen removal values in these experiments were up to 9 %, 40 %, and 65 % higher than those with FDO, respectively. However, high-frequency Air-SAT during continuous flooding also led to significant deterioration of the mean infiltration rate, probably due to enhanced biological clogging. Hence, it may be more feasible and beneficial to combine it with conventional FDO, allowing a steady infiltration rate and increased recharge volumes while sustaining high effluent quality. While these results still need to be verified at full scale, they highlight the possibility of using air injection to minimize the DP length and alleviate the pressure on existing SAT sites.

P-275 Oxidation reduction potential (ORP) levels in blood plasma could represent the ORP status in follicular fluid from oocyte donors and patients

Abstract Study question Does the evaluation of oxidation-reduction potential (ORP) levels in blood plasma from subfertile patients and oocyte donors represents the ORP status in follicular fluid? Summary answer ORP levels in blood plasma from oocyte donors and sub fertile patients could be an indicator of oxidative stress in follicular fluid What is known already Oxidation-reduction potential (ORP) measurement of seminal plasma is one method to diagnose oxidative stress in male patients, which can help physician to recommend antioxidants administration when it is elevated. Seminal plasma is easily accessible by masturbation. An empirical analogue for semen could be follicular fluid (FF). Unfortunately, it is very difficult to access to FF, unless a surgical procedure is performed. Hence, it is necessary to find indirect parameters to evaluate the ORP status in FF. Since blood plasma (BP) circulation provides antioxidants to the FF, we studied the BP ORP measurement to indirectly determine ORP levels in FF. Study design, size, duration Prospective study conducted at CITMER, Mexico from December 2022 to January 2023. We included under informed consent 15 oocyte donors (age 26.8 ± 4.06 years old) and 55 patients (age 35.2 ± 4.8 years old) undergoing IVF/ICSI. Participants/materials, setting, methods ORP levels in BP and FF from dominant follicles were measured at the same time of oocyte collection with MiOXSYS system. Oocytes were inseminated and zygotes were cultured until blastocysts stage. We calculated correlation of a) ORP levels in FF vs BP, b) ORP of FF and BP vs number of retrieved oocytes, c) ORP of FF and BP vs number of fertilized oocytes, d) ORP of FF and BP vs number of blastocysts Main results and the role of chance A total of 172 oocytes from oocyte donors were collected. After fertilization check, 135 zygotes (78%) were observed. A total number of 55 blastocysts (31%) were observed at day 5 + day 6. For patients, a total of 550 oocytes were collected, 360 zygotes were observed (65%) and 164 blastocysts at day 5 + day 6 were obtained (45%). The correlation between ORP levels from FF and BP for oocyte donors was 0.90 and 0.51 for patients. The overall ORP levels in FF and BP in patients were 136.2 ± 14.9 mV and 148.3 ± 15.97 mV, respectively. For oocyte donors, ORP levels in FF and BP were 160.3 ± 13.8 mV and 170.28 ± 17.67mV, respectively. There was a mild correlation of ORP levels in BP with numbers of oocytes retrieved (r = 0.25). The correlation of BP ORP with oocyte fertilization was 0.24 in patients with autologous oocyte utilization. The mean ORP levels of FF were 136.2 ± 14.9 mV, versus a mean ORP of 148.3 ± 15.97 mV in BP. The FF ORP levels between 100-150 mV [LRD1] were moderately correlated and predictive of blastocyst development [LRD2]. For donor oocytes there was a weak negative correlation [LRD3] of FF ORP with oocyte fertilization (-0.06) and a weak negative correlation for blastocyst formation was found (-0.18). Limitations, reasons for caution The MiOXSYS System ( Careous Biotechnology, Lituania) is a device calibrated to measure ORP levels in seminal plasma but not to measure ORP levels in FF nor BP. The number of analyzed data should be increased. Wider implications of the findings According to this study, the use of blood plasma to surrogate the measurements of ORP levels in follicular fluid could represent a further strategy to include female patients to be treated by antioxidants before an IVF treatment. Trial registration number None

Influence of redox potential on the accumulation of poly(3-hydroxybutyrate) by Bacillus megaterium.

The main goal of the present study was to evaluate the oxidation-reduction potential (ORP) on the production of poly(3-hydroxybutyrate) (P(3HB)) by Bacillus megaterium. Each microorganism has an optimal ORP range, and changes to the culture medium's ORP may redistribute the cell's metabolic flux, as such, the measurement and control of the ORP profile allows one to, in a way, manipulate the microbial metabolism, affecting the expression of certain enzymes and allowing for better control over the fermentative process. The ORP tests were carried out in a fermentation vessel coupled with an ORP probe, containing 1L of mineral medium added with agroindustry byproducts (60% v/v of confectionery wastewater, and 40% v/v of rice parboiling water). The system's temperature was kept at 30°C, with an agitation speed of 500rpm. The vessel's airflow rate was controlled via a solenoid pump based on the ORP probe's data. Different ORP values were evaluated to verify their impact on biomass and polymer production. Cultures using OPR levels of 0mV displayed the highest amounts of total biomass (5.00gL-1) when compared to -20mV and -40mV (2.90g L-1 and 0.53g L-1, respectively). Similar results were also found for P(3HB)-to-biomass ratio, with polymer concentration being reduced when using ORP levels below 0mV and with a maximum amount of polymer-to-biomass ratio of 69.87% after 48h of culture. Furthermore, it was possible to observe that the culture's pH can also affect total biomass and polymer concentration, albeit to a lesser extent. Thus, when considering the data found during this study, it is possible to observe that ORP values can greatly impact B. megaterium cell's metabolism. Furthermore, the measurement and control of ORP levels may be an invaluable asset when trying to maximize polymer production under different culture conditions.

Enhancement of butanol production in Clostridium acetobutylicum SE25 through oxidation-reduction potential regulation and analysis of its metabolic mechanisms

In this study, an exogenous regulatory strategy named as oxidation-reduction potential (ORP) regulation was performed in the butanol biosynthesis process by Clostridium acetobutylicum SE25 to accelerate the carbon metabolism flow to butanol and enhance butanol production. The findings show that the dithiothreitol and potassium ferricyanide were the optimal redox agents for regulating the ORP of the fermentation system. Specifically, when the ORP value of fermentation broth was controlled at −400 mV, the highest production of butanol (14.30 ± 0.65 g/L) was obtained, which was 10.80 % higher than that of the control group. And the yield and productivity of butanol were 0.24 g/g and 0.24 g/L/h, respectively. Furthermore, the physiological mechanisms of the effects of different ORP levels on butanol synthesis was investigated, and the results demonstrate that ORP could both regulate the level and ratio of energy charge and NADH/NAD+, and redistribute metabolic flux. Thus, the ORP control strategy, according to the results in this study, is an effective and attainable approach to obtain the high production of butanol.

P-226 Efficiency of different antioxidants in reducing the supra-physiological Oxidation Reduction Potential Levels in human embryo culture media

Abstract Study question Does every antioxidant compounds perform similarly in reducing the excessive levels of Oxidation Reduction Potential (ORP) in IVF culture media? Summary answer Not all antioxidant compounds perform similarly in maintaining physiological ORP levels in IVF culture media. What is known already During assisted reproduction technologies (ART), several external factors are responsible for disturbing the ORP equilibrium in gametes and embryos. Therefore, antioxidant supplementation of culture media has been evaluated and reported. However, there is lack of consensus on the efficiency of antioxidant action in embryo culture media. Antioxidants are known to lower the levels of free radical concentration to physiological levels, preventing cellular damage caused by oxidative stress. Therefore, it is important to determine which antioxidant compound are the most effective in reducing ORP levels in embryo culture media. Study design, size, duration In this prospective study was performed at CITMER Reproductive Medicine, Mexico city. ORP levels were measured by MiOXSYS System (UAB Caerus Biotechnologies, Vilnius, Lithuania) in embryo-free culture medium (Global® Total®, LifeGlobal®, Connecticut, US). Embryo-free culture medium was supplemented with cumene hydroperoxide and seven different antioxidants were tested each day for 5 continuous days (n = 40). Follicular fluid ORP levels from dominant follicles of 40 oocyte donors were used as control and considered as a physiological target. Participants/materials, setting, methods Cumene hydroperoxide (CH) 1mM, was utilized to increase ORP values in culture media from 224 mV to 415 mV. The following compounds considered as antioxidants according to literature were supplemented at 2 mM to the CH culture media: Ascorbic acid (ASC), L-Carnitine (CAR), L-Cysteine (CYS), Glutathione (GLT), Curcumin (CU), Resveratrol (RSV) and b-Mercaptoethanol (BME). ORP levels were quickly evaluated each time. Main results and the role of chance In this study, CH was used as a culture media oxidant to measure the antioxidants capacity in lowering the excessive ORP values of CH culture media. ORP in CH solution was 415 mV ± 4.3. All antioxidants showed a statistically different capacity (p < 0.05) to lower the ORP values when added to CH solution: RSV decreased the ORP to 348.3 mV ± 3.6 p = 0.0449, CAR to 316.32 mV ± 4.7 (p < 0.0001), CU to 315.7 mV ± 4.4 (p < 0.0001) and GLT to 258.4 mV ± 15.1 (p = 0.00002). The compounds that showed higher antioxidant capacity were CYS 158.4 mV ± 4.7 (p < 0.00001), ASC 154.1 mV ± 3.1 (p < 0.00001) and BME 136.1 mV ± 9.6 (p < 0.00001). CYS, ASC and BME ORP values reached the physiological ORP values found in follicular fluid from donors, which are 89 mV±23.6 mV. Limitations, reasons for caution Further studies should focus on the comparison between physiological dynamics of antioxidant supplementation on culture media and molecular and biochemical effect of antioxidants on embryos and gametes. Wider implications of the findings According to our results, CYS, ASC and BME were significantly more potent antioxidants in lowering the ORP in culture medium to physiological levels. The measurement of antioxidant capacity in lowering excess of ROS in culture media may assist in developing the most effective antioxidant supplements, thus improving ART outcomes. Trial registration number none

P-291 Positive effects of inactivated blood serum in stabilizing the activity of antioxidants in embryo-free culture media

Abstract Study question Does addition of blood serum to embryo culture media supplemented with antioxidants (AOXs) helps maintain the AOX activity under in vitro culture conditions? Summary answer The addition of inactivated blood serum (IBS) before AOX supplementation resulted in AOX activity stabilization in embryo-free culture media (EFCM) for up to 48 hours. What is known already Supra-physiological levels of reactive oxygen species (ROS) in embryo culture medium (ECM) can disturb embryo development possible due to oxidative stress. Hence, AOX supplementation of ECM has been used to counteract the potential negative effects of high ROS on gametes and embryos. However, rapid consumption of AOXs via interaction with ROS may reduce the AOX protection capacity particularly during extended culture conditions. The aim of this study is to investigate the efficacy of IBS in stabilizing the AOX activity of a combination of AOXs (EmbryORP®) when added to EFCM. Study design, size, duration In this prospective study, oxidation reduction potential (ORP) was assessed in EFCM by MiOXSYS System (UAB Caerus Biotechnologies, Vilnius, Lithuania). The ORP results reflect the overall balance between oxidants and antioxidants. ORP levels in follicular fluid obtained from dominant follicles of 40 oocyte donors were used as control. Participants/materials, setting, methods All dishes containing culture medium (GlobalTotal®, LifeGlobal®, Connecticut, US) were incubated for 48 hours in 8% CO2, 20% O2, 37 °C. Culture dishes were divided into four groups: Group A: EFCM without AOX, Group B: EFCM+AOX, Group C: EFCM+AOX+IBS, and Group D: EFCM+IBS. Levels of ORP were assessed in EFCM before AOX supplementation (0), immediately after adding AOX (1) and 48 hours following AOX supplementation (2). ORP results are expressed as millivolts (mV). Main results and the role of chance At 48 hours of culture, ORP value in group C (96.7 mV) was significantly lower than group A (345 mV; p = 0.00001), and was found to be similar to the physiological ORP values found in follicular fluid from donors (89 mV±23.6 mV; p > 0.05). Also, ORP value in group C (96.7 mV) was lower than group B (210 mV; p = 0.67) and group D (280.1 mV; p = 0.11). Limitations, reasons for caution This study only tested the efficacy of IBS as AOX stabilizer in EFCM over 48 hours. The efficacy and potential risks associated with the use of IBS during actual embryo culture were not examined. Wider implications of the findings The use of AOX stabilizers may represent an important novel finding to maintain sufficient AOX protective capacity during extended culture conditions. Trial registration number 10112021-AOX

Effects of antioxidant co-supplementation therapy on spermatogenesis dysfunction in relation to the basal oxidation-reduction potential levels in spermatozoa: A pilot study.

PurposeIn this pilot study, the authors compared the effects of antioxidant co‐supplementation therapy and methylcobalamin therapy in patients with impaired semen quality.MethodsEighty‐four subjects who visited male infertility clinics and showed abnormal semen test results were randomly subjected to one of the two therapies: antioxidant co‐supplementation therapy with vitamin C, vitamin E, coenzyme Q10, and flaxseed oil or methylcobalamin therapy. The oxidation–reduction potential (ORP) and 8‐hydroxy‐2′‐deoxyguanosine levels were used as indicators of oxidative stress levels in semen. Semen analysis was also performed.ResultsThe authors obtained results from 67 patients who had completed 3 months of treatment. Neither antioxidant co‐supplementation therapy nor methylcobalamin therapy changed the semen parameters significantly (except for the sperm concentration, which was increased by the latter therapy). When the pre‐treatment ORP value in semen was higher than the cutoff value, both therapies significantly increased the sperm concentration. The 8‐hydroxy‐2′‐deoxyguanosine level did not yield any meaningful predictive value with regard to increased sperm concentrations.ConclusionsBoth antioxidant co‐supplementation therapy and methylcobalamin therapy increased the sperm concentration in patients with impaired semen quality when the basal ORP levels in their semen were elevated.

The Effect of Wastewater Irrigation on the Activity of Soil Microorganisms

Introduction: The use of wastewater for irrigation in arid and semi-arid regions of the world is increasing. This study aimed to evaluate the effects of wastewater on the microbial activity of irrigated soils using the enzymatic activity of soil microorganisms. Materials and Methods: In this study, for soil irrigation, the secondary effluent of the Isfahan municipal wastewater treatment plant was used. As a control, tap water that has no microbial load was also used. Soil samples were collected in two stages, before and immediately after irrigation. All samples were collected in sterile bags, transferred immediately to the laboratory for physicochemical and microbiological tests. Soil samples were analyzed for the amounts of enzymatic activity (Fluorescein Diacetate (FDA) and dehydrogenase), electrical conductivity (EC), oxidation-reduction potential (ORP), and pH. Results: The EC levels before and after irrigation with tap water was 231.2 and 260.63 µs.cm-1, respectively, which was significantly different from levels of wastewater-irrigated soil (P < 0.05). pH in the two types of used water before and after irrigation was 6-8 and 7-8, respectively. No significant difference was observed in the levels of FDA, dehydrogenase, ORP, and microbial population in samples irrigated with water and wastewaters (p > 0.05). It was found that there is a significant relationship between bacterial density and FDA (P < 0.05). Conclusion: The results of the study showed that irrigation with wastewater has no significant effect on the microbial activity of irrigated soil. Because of the short-term wastewater irrigation in the present study, however, further investigation is needed to evaluate the effect of long-term wastewater irrigation on the microbial and physicochemical quality of soil.

IMPACT OF DIET ON SPERM OXIDATION-REDUCTION POTENTIAL

The objective of the present study was to investigate the impact of the diet on sperm oxidation-reduction potential. Since the male contribution to the fertility of a couple is crucial, it is of high importance to determine the dietary factors that can affect male fertility. This study was based on semen analyses of 20 males including 10 males who do not eat pork meat and 10 males with no diet restriction who consume pork meat et least three times per week. The age of the men ranged from 25 to 49 years. The main exclusion criteria were smoking and obesity. All participants followed a period of 3–5 days of sexual abstinence. All specimens were analyzed within 1 hour of collection. The oxidation-reduction potential (ORP) was measured using novel galvanostat-based technology—the MiOXSYS System (Aytu BioScience, Inc.). Briefly, 30 μL of liquefied semen at room temperature was applied to the MiOXSYS sensor. Both absolute ORP (mV) and normalized sORP values (mV/106 sperm/ml) based on sperm concentration were calculated. Each sample was measured in duplicate. All variables were analyzed by IBM SPSS version 24 (IBM Corp., Armonk, NY, USA). Differences with p ≤0.05 were considered statistically significant. Descriptive statistics between the two investigated groups showed the significant difference was in sORP (mV/106 sperm/mL) values, where the group which does not consume pork meat showed a lower range compared to males without diet restriction [0.43 (0.6-0.74) vs 1.52 (0.64-2.81) respectively, p<0.001]. Our study showed that the participants which did not consume pork meat had decreased ORP levels. Many studies previously confirm the negative impact of Trans fatty acids, or milk products milk, on sperm parameters. However, to confirm our preliminary findings further studies including larger cohorts are warranted.

Response of microbial community composition and function to emergent plant rhizosphere of a constructed wetland in northern China

To understand the mechanisms by which emergent plants influence the microbial communities in wetland sediments, we analyzed the response of microbial composition, abundance, metabolic activity, and metabolic genes to three emergent plant species [Cyperus alternifolius L. (Cyp), Typha angustifolia L. (Typ), and Phragmites australis (Cav.) Trin. ex Steud. (Phr)], and determined the important physicochemical properties of the soils and root exudates in Zhaoniu River Constructed Wetland in northern China. We found the composition of both the microbial communities and the metabolic genes differed between rhizosphere and non-rhizosphere sediments. The rhizosphere microbial abundance in Phr in summer was significantly higher than in the other two plants and in the non-rhizosphere. The rates of microbial respiration and ammonia oxidation in rhizosphere sediments were significantly higher than those in non-rhizosphere sediments. Our statistical analyses showed that the total organic carbon (TOC) concentration in root exudates and the oxidation–reduction potential (ORP) significantly influenced the differences in the composition, abundance, and metabolic activities of the microbial community and metabolic genes between rhizosphere and non-rhizosphere sediments, suggesting that the secretion of root exudates and oxygen by emergent plants was the main mechanism affecting the composition and function of the microbial community. As the result of the high levels of TOC and the ORP, the rhizosphere sediments showed relatively high abundances of the genes related to biodegradation of xenobiotic compounds. By contrast, non-rhizosphere sediments showed relatively high abundances of genes related to carbon fixation and sulfate reduction, possibly due to the low levels of TOC and ORP. Plants with an enhanced ability to secrete root exudates and oxygen, such as Phr, should be preferred in constructed wetlands to increase the metabolic activity of sediment microbial communities. This study extends our understanding of the mechanisms by which the plant rhizosphere affects the ecological functions of wetlands.

Protective Effect of Calcium Dobesilate on Induced AKI in Severely Burned Mice

Background: Early acute kidney injury (AKI) predicts a high mortality rate in severely burned patients. However, the pathophysiology of early AKI induced by severe burn has not been well-defined. This study was designed to examine the protective effects of calcium dobesilate (CaD) against severe burn-induced early AKI in mice and explore the mechanism. Methods: The shaved backs of mice were immersed in 100°C water for 10 s to make severe burn (40% of the total body surface area). CD-57 male mice were randomly divided into sham, burn, burn + vehicle, and burn + CaD groups. Renal function, reactive oxygen species generation, tubular necrosis, and phosphorylation of mitogen-activated protein kinase, protein kinase B (Akt), and nuclear factor (NF)-κB were measured at 24 and 48 h after the burn. Renal histology, ELISA, qRT-PCR, and Western blotting were performed on the renal tissue of mice to examine the effects and mechanisms at 24 and 48 h after the burn. Results: Tubular damage, cast formation, and elevations of serum creatinine, BUN, and renal tissue kidney injury molecule 1 levels were all observed in the burned mice, and these were all alleviated in the mice with CaD treatment. In addition, the levels of oxidation-reduction potential and malondialdehyde were decreased, while the activities of the endogenous antioxidative enzymes were increased in the kidney tissues from the mice after CaD treatment. Furthermore, the activities of Akt, p38, extracellular sign-regulated kinase, Jun N-terminal kinase, and NF-κB signaling were increased in the kidney of burned mice and normalized after CaD treatment. Conclusion: This study has established, for the first time, the protective effect of CaD against early AKI in severely burned mice. CaD may exert its protective effect through alleviating oxidative stress, apoptosis, and inflammation, as well as modulating some signaling pathways in the kidney.

The association of seminal oxidation reduction potential with sperm parameters in patients with unexplained and male factor ınfertility.

ABSTRACTPurpose:Understanding the effects of high oxidation reduction potential (ORP) levels on sperm parameters will help to identify patients with unexplained and male factor infertility who may have seminal oxidative stress and determine if ORP testing is needed. This study aimed to evaluate the association between seminal ORP and conventional sperm parameters.Materials and Methods:A total of 58 patients who provided a semen sample for simultaneous evaluation of sperm parameters and ORP between January and September 2019 were enrolled in this retrospective study. To identify normal and high ORP levels, a static ORP (sORP) cut-off value of 1.36mV/106sperm/mL was used. Sperm parameters were compared between infertile men with normal sORP (control group, n=23) and high sORP values (study group, n=35).Results:Men with sORP values >1.36mV/106sperm/mL had significantly lower total sperm count (TSC) (p <0.001), sperm concentration (p <0.001) and total motile sperm count (TMSC) (p <0.001). In addition, progressive motility (p=0.04) and fast forward progressive motility (p <0.001) were significantly lower in the study group. A negative correlation was found between sORP and TSC (r=-0.820, p <0.001), sperm concentration (r=-0.822, p <0.001), TMSC (r=-0.808, p <0.001) and progressive motility (r=-0.378, p=0.004). Non-progressive motility positively correlated with sORP (r=0.344, p=0.010).Conclusions:This study has shown that TSC, sperm concentration, progressive motility and TMSC are associated with seminal oxidative stress, indicated by a sORP cut-off of 1.36mV/106sperm/mL. Presence of oligozoospermia, reduced progressive motilty or low TMSC in sperm analysis should raise the suspicion of oxidative stress and warrants seminal ROS testing.

Influence of Non-Thermal Atmospheric Pressure Plasma Jet on Extracellular Activity of α-Amylase in Aspergillus oryzae

In a previous study, we found that plasma can enhance spore germination and α-amylase secretion in A. oryzae, a beneficial fungus used in fermentation. To confirm this, in the current study, we investigated the effects of plasma on development and α-amylase secretion using an enlarged sample size and a different plasma source: a plasma jet. There was a ~10% (p &lt; 0.01) increase in spore germination upon non-thermal atmospheric pressure plasma jet (NTAPPJ) treatment for 5 min and 10 min, as compared with the control (no plasma treatment). The activity of α-amylase detected in potato dextrose broth (PDB) media during incubation was significantly elevated in plasma-treated samples, with a more obvious increase upon 10 min and 15 min treatments and 24–96 h incubation periods. The levels of the oxidation reduction potential (ORP) and NOX (nitrogen oxide species) were higher in the plasma-treated samples than in the control samples, suggesting that these two variables could serve as standard indicators for enhancing α-amylase activity after plasma treatment. Genome sequencing analysis showed approximately 0.0016–0.0017% variations (changes in 596–655 base pairs out of a total of 37,912,014 base pairs) in the genomic DNA sequence of A. oryzae after plasma treatment. Our results suggest that NATPPJ can enhance the spore germination and extracellular activity of α-amylase, probably by increasing the levels of ORP and NOX to an optimum level.

Synergistic association between cytochrome bd-encoded Proteiniphilum and reactive oxygen species (ROS)-scavenging methanogens in microaerobic-anaerobic digestion of lignocellulosic biomass

Intermittent (every other day) microaerobic [picomolar oxygen by oxidation-reduction potential (ORP) set at +25 mV above anaerobic baseline] digestion of lignocellulosic biomass showed higher digestibility and better stability at a high organic loading rate (OLR) of 5 g volatile solids (VS)/L/d than that under strict anaerobic conditions. However, the microbial mechanisms supporting the delicate balance under microaeration remain underexplored. On the basis of our previous findings that microbial communities in replicate experiments were dominated by strains of the genus Proteiniphilum but contained diverse taxa of methanogenic archaea, here we recovered related genomes and reconstructed the putative metabolic pathways using a genome-centric metagenomic approach. The highly enriched Proteiniphilum strains were identified as efficient cellulolytic facultative bacterium, which directly degraded lignocellulose to carbon dioxide, formate, and acetate via aerobic respiration and anaerobic fermentation, alternatively. Moreover, high oxygen affinity cytochromes, bd-type terminal oxidases, in Proteiniphilum strains were found to be closely associated with such picomolar oxygen conditions, which has long been overlooked in anaerobic digestion. Furthermore, hydrogenotrophic methanogenesis was the prevalent pathway for methane production while Methanosarcina, Methanobrevibacter, and Methanocorpusculum were the dominant methanogens in the replicate experiments. Importantly, the two functional groups, namely cellulolytic facultative Proteiniphilum strains and methanogens, encoded various antioxidant enzymes. Energy-dependent reactive oxygen species (ROS) scavengers (superoxide reductase (SOR) and rubrerythrin (rbr) were ubiquitously present in different methanogenic taxa in response to replicate-specific ORP levels (-470, -450 and -475 mV). Collectively, cytochrome bd oxidase and ROS defenders may play roles in improving the digestibility and stability observed in intermittent microaerobic digestion.

High levels of oxidation-reduction potential in frozen-thawed human semen are significantly correlated with poor post-thaw sperm quality.

This study examined the relationship between oxidation-reduction potential (ORP) in frozen-thawed semen and the post-thaw sperm parameters. Levels of ORP were measured in 25 samples from men presenting for routine infertility work-up and were expressed as millivolt (mV)/106 sperm/ml. Frozen-thawed samples were examined for post-thaw total motility (TM%), progressive motility (PM%), total sperm count (TSC) and ORP. The cryo-survival rate (CSR) was calculated as post-thaw TM/pre-freeze TM×100. Data are provided as median and interquartile range (25th and 75th percentiles). The post-thaw TM% (10.0% [4.00%, 15.1%]), PM% (5.88% [2.97%, 9.33%]) and TSC (12.5 [10.0, 17.5]×106 sperm) were significantly lower than the pre-freeze TM% (45.9% [32.9%, 59.1%], PM% (31.5% [24.4%, 40.0%] and TSC (120 [90, 250] ×106 sperm) (p<.001). Post-thaw ORP (2.62 [2.52, 3.13]mV/106 sperm/ml) was significantly higher than pre-freeze ORP (0.73 [0.54, 1.21]mV/106 sperm/ml; p<.001). The CSR was 21.7% (11.3%, 31.9%). The post-thaw seminal ORP was negatively correlated with post-thaw TM% (r=-.5; p=.02), PM% (r=-.41; p=.03), TSC (r=-.60; p=.03) and CSR (r=-.52; p=.01). Increased levels of ORP are significantly correlated with poor post-thaw sperm quality and CSR.

The effect of oxidative and reductive stress on semen parameters and functions of physiologically normal human spermatozoa

Both oxidative stress (OS) and reductive stress (RS) are the two extreme facets of redox imbalance that can have deleterious effects on sperm function. However, there is a lack of information on the physiological range of oxidation-reduction potential (ORP). The aim of this study was to investigate the effect of OS and RS on functions and associated molecular changes in normal spermatozoa in order to establish the physiological range of ORP. In the current study, total and progressive motility remained unchanged in spermatozoa exposed to ORP values 0.33 and 0.72 mV/106 sperm/mL. However, a significant (P < 0.05) decline in total and progressive motility were observed at ORP values 1.48, 2.75, −11.24, −9.76 and −9.35 mV/106 sperm/mL. Sperm vitality also decreased significantly (P < 0.0001) at 2.75, −11.24 and −9.76 mV/106 sperm/mL. Spermatozoa exposed to ORP levels 2.75 and −11.24 mV/106 sperm/mL showed a significant (P < 0.01) decrease in mitochondrial membrane potential. Intracellular reactive oxygen species (iROS) production increased (P < 0.05) in spermatozoa exposed to ORP levels of 1.48 and 2.75 mV/106 sperm/mL, while iROS decreased (P < 0.05) at ORP levels −9.76 and −11.24 mV/106 sperm/mL. No significant change in sperm DNA fragmentation was noted in sperm exposed to OS/RS and the values were below the reference range (<19.25%). Western blot analysis revealed decreased expression of CV-ATPA, CIII-UQCRC2 and CIV-MTCO1 proteins at 60 and 120 min (P < 0.05) in both OS and RS conditions. This is the first study to report physiological range of ORP (between −9.76 and 1.48 mV/106 sperm/mL) and to elucidate the role of altered expression of oxidative phosphorylation (OXPHOS) complexes proteins in mediating detrimental effects of oxidative and reductive conditions on sperm functions. A decreased expression of OXPHOS proteins and associated mitochondrial dysfunction contributes to decreased sperm motility and vitality under oxidative and reductive stress.

The efficacy of oxidation reduction potential(ORP) in male infertility and its relationship with seminal leukocyte concentration

Reactive oxygen species (ROS) in semen has been reported to have negative effect to male fertile capacity, and recent studies reported the efficacy of oxidation-reduction potential (ORP) which reflects the balance of oxidants and antioxidants in semen. The source of ROS in semen is considered as immature spermatozoa and seminal leukocytes, but the detail is still unknown. The aim of this study is to evaluate the relationship between the concentration of seminal leukocytes and oxidative stress level using ROS, ORP. Retrospective study. Between April 2018 and March 2019, 29 infertile males who visited Reproduction Centre of Yokohama City University Medical Center were enrolled. All patients underwent semen analysis and measurement of ROS and ORP levels. The ROS level in semen was measured using Monolight 3010TM Luminometer and the ORP level was measured using MiOXSYS SystemTM. The concentration of peroxidase-positive leukocytes were evaluated using myeloperoxidase staining (Endtz test). The relationship between ROS levels, ORP levels, the concentration of leukocytes and semen parameters were evaluated using correlation analysis. The sperm concentration and motility were 39.6±36.6×106/ml, 30.0±18.9 %, respectively. The total ROS level was 9328.9 (±18851) Relative Light Units, and the ORP level was 46.1(±38.7) mV. The ROS level was significantly correlated with ORP level (r=0.79, p<0.01). The concentration of leukocytes measured by Endtz test was positively correlated with both ORP level (r=0.46, p=0.023) and ROS level (r=0.82, p<0.01). ORP level was negatively correlated with sperm concentration (r= -0.41, p=0.026), while ROS level didn’t show significant correlation with every semen parameters. To our knowledge, this is the first study that showed the significant correlation between ORP levels and seminal leukocytes concentration. Our study suggested that peroxidase-positive leukocyte is one of the main source of ROS in semen. Although ROS was strongly correlated with leukocyte concentration, ORP level is considered to have better potential to reflect the sperm quality.

Correlation of oxidation-reduction potential with hormones, semen parameters and testicular volume.

Seminal oxidative stress (OS) is a major cause of male factor infertility and can be measured as oxidation-reduction potential (ORP). Studies showed significant negative relationships of ORP with sperm count, motility or DNA integrity. Since these parameters are also positively or negatively associated with reproductive hormones follicle-stimulating hormone (FSH), luteinising hormone (LH), testosterone, testicular volume and the occurrence of varicocele, it is important to understand the mechanistic relationship between ORP and hormonal and/or testicular parameters. Therefore, we studied the relationship between ORP levels, standard hormone profiles and testicular volume in infertile men with and without varicocele. Results show a highly significant negative relationship of ORP with testicular volume and significantly positive correlations with FSH and LH. Yet, when adding varicocele as covariate, the relationship with FSH/LH became nonsignificant. Contrary, the presence of varicocele had only a contributing influence on the association of ORP with the testis volume. No association was found with estradiol. We propose that since OS causes degeneration of Sertoli cell with testicular shrinkage, such negative effect would result in a negative feedback on the hypothalamus with less inhibin secretion. This may result in increased secretion of LH and FSH. Thus, systemic and/or local OS may be responsible for smaller testis volumes.

Enhanced degradation of pyrene and phenanthrene in sediments through synergistic interactions between microbial fuel cells and submerged macrophyte Vallisneria spiralis

Purpose Submerged macrophyte Vallisneria spiralis and sediment microbial fuel cell (SMFC) systems are cost-effective methods for the remediation of polycyclic aromatic hydrocarbon (PAH)-polluted sediments. This study evaluates whether the combination of these two ecological approaches could further improve the removal efficiency of PAHs from sediments and investigates the possible mechanisms of removal. Materials and methods Sediments, macrophytes, electrodes, and plexiglass columns were used to construct an experimental microcosm. A 65-day comparative study was performed with six treatments as follows: SMFC without PAH (SMFC); PAH only (PAH); SMFC with PAH (SMFC-PAH); V. spiralis without PAH (macrophyte); V. spiralis with PAH (macrophyte-PAH); V. spiralis with SMFC and PAH (M-SMFC-PAH). Pyrene and phenanthrene were added to raw sediments to obtain initial PAH concentrations of 10 mgkg(-1) dry sediment. The monitored parameters were sediment oxidation-reduction potential (ORP); low molecular weight organic acids (LMWOAs) and Fe (II) concentrations in pore water; electron acceptor (sulfate and Fe (III)), humic acid (HA), and PAH concentrations in sediments; and plant morphology and root physiology. High-throughput 16S rRNA gene sequencing was also performed to assist mechanistic understanding. Results and discussion The M-SMFC-PAH treatment obtained the highest sediment ORP and PAH removal efficiency. The average ORP level in M-SMFC-PAH was increased by 57.2, 59.1, and 168.4 mV, compared with the SMFC-PAH, macrophyte-PAH, and PAH-only treatments, respectively, with a mean value of 121.7 mV observed during the whole experimental period. The pyrene (phenanthrene) dissipation ratios at the end of the experimental period were 29.1% (35.4%), 45.5% (56.3%), 59.8% (67.3%), and 79.4% (88.2%) for PAH only, SMFC-PAH, macrophyte-PAH, and M-SMFC-PAH treatments, respectively. The highest correlation was observed between PAH concentration and sediment ORP value, in the coupled M-SMFC-PAH system. Conclusions Results suggest that the interactions between the anode and rhizosphere of V. spiralis were synergistic during PAH removal. The coexistence of anodic and rhizospheric oxygen loss in sediments had a synergistic effect on PAH degradation. Plant presence facilitated the electrogenic degradation of PAHs. The inhibited growth of V. spiralis due to PAH toxicity was reduced by electrogenesis, thus facilitating the removal of vegetable PAHs from sediments. Coordinated growth of anaerobic and aerobic PAH degrading bacteria on the anode was a key factor in the optimal removal of PAHs in coupled systems.