Aerobic Microbial Cometabolism of Benzothiophene and 3-Methylbenzothiophene

A culture enriched by growth on 1-methylnaphthalene was used to study the aerobic biotransformations of benzothiophene and 3-methylbenzothiophene. Neither of the sulfur heterocyclic compounds would support growth, but they were transformed by the culture growing on 1-methylnaphthalene or glucose or peptone. Cometabolism of benzothiophene yielded benzothiophene-2,3-dione, whereas that of 3-methylbenzothiophene yielded 3-methylbenzothiophene sulfoxide and the corresponding sulfone. The identities of the dione and sulfone were verified by comparison with authentic standards. The identity of the sulfoxide was surmised from gas chromatography-mass spectrometry and gas chromatography- Fourier transform infrared spectroscopy results. Oxidation preferentially occurred at carbons 2 and 3 in benzothiophene, but when carbon 3 was substituted with a methyl group, as in 3-methylbenzothiophene, the sulfur atom was oxygenated. The predominant microorganism in the enrichment culture was a Pseudomonas strain, designated BT1, which mineralized aromatic but not aliphatic hydrocarbons. This isolate cometabolized benzothiophene and 3-methylbenzothiophene. There was no evidence that it could metabolize 3-methylbenzothiophene sulfone. When 3-methylbenzothiophene was added to Prudhoe Bay crude oil, the sulfur heterocycle was oxidized to its sulfoxide and sulfone by strain BT1 as it grew on the aromatic hydrocarbons in the crude oil. Benzothiophene-2,3-dione was found to be chemically unstable when incubated with Prudhoe Bay crude oil. Thus its formation from benzothiophene in the presence of crude oil could not be determined.     

Freeze-dried microalgae of Nannochloropsis oculata improve soybean oil's oxidative stability

Marine microalga Nannochloropsis oculata possesses nutrients valuable for human health. In this study, we added freeze-dried N. oculata powder to soybean oil and observed a remarkable inhibition in oil oxidation. The amount of microalgae powder added was positively correlated to the increase in oil stability. The addition of 5.0 % (w/w) microalgae powder increased the oil stability index (OSI) values of soybean oil more than twofold at the tested temperatures 120 and 130 °C. N. oculata contains high levels of both phenolic compounds and α-tocopherols that could be the contributors to such an increase of the OSI. Two methods were conducted to assay the active ingredients released from microalgae: one employed three solvent systems to extract the microalgae and the other was the soybean oil added with microalgae. Analyses of free radical scavenging and reducing power suggested that the phenolic compounds dominated the antioxidation activities in soybean oil when it was infused with the microalgae powder. Our results suggest that N. oculata could potentially be used as an additive in cooking oil to increase the shelf life and nutritional value of the oil and to reduce the production of free radicals from lipid oxidation when the oil is used at high-temperature cooking processes.     

The in vitro effect of DDT and related compounds on the succinoxidase system of rat heart

DDT and several of its related compounds were found to be inhibitory to rat heart succinoxidase at concentrations of from 10^?4 to 10^?5M, the degree of inhibition being about 70–90% at the higher concentrations. This inhibition could also be shown for cytochrome oxidase, but not for succinic dehydrogenase. The inhibition was demonstrable when the insecticide or its derivatives were added to the enzyme system as alcoholic solutions. Cholesterol at the same concentrations did not inhibit succinoxidase.When DDT was present in an oil emulsion, only a slight inhibition could be shown toward the succinoxidase system, even though the concentration in the emulsion was 10 times that of the highest level in alcohol.DDA, the acetic acid derivative of DDT, and a known metabolite thereof, was much less inhibitory toward the succinoxidase and cytochrome oxidase systems, even at 5 × 10^?4M.     

Energy-dependent accumulation of iron by isolated rat liver mitochondria V. Effect on factors controlling respiration and oxidative phosphorylation

1. Depending on the metabolic state, the addition of iron(III)-sucrose induces an inhibition or a stimulation of the respiration rate when added to isolated rat liver mitochondria.2. Under conditions identical to those used in the accumulation studies (Romslo, I. and Flatmark, T. (1973) Biochim. Biophys. Acta 305, 29?40), the ferric complex induces a decrease in the oxygen uptake concomitant to an oxidation of cytochromes c (+c₁) and a (+a₃). These results suggest that ferric iron is reduced to ferrous iron by the respiratory chain prior to or simultaneously with its energy-dependent accumulation.3. On the other hand, the addition of iron(III)-sucrose induces a stimulation of respiration in State 4 and State 3 provided Mg²⁺ is present in the suspending medium. In contrast to Ca²⁺, iron stimulates State 4 respiration in a cyclic process only within narrow concentration limits; at concentrations of iron above 100 μM the respiration remains in the activated state until anaerobiosis. The stimulation of State 4 respiration is more pronounced with succinate than with NAD-linked substrates, a difference which partly may be attributed to a stimulation of the succinate dehydrogenase complex.4. The stimulation of respiration by iron is approx. 3 times higher in State 3 than in State 4 and this difference can be attributed to a stimulation of the adenine nucleotide exchange reaction in State 3 with a concomitant increase in the rate of oxidative phosphorylation, although the $\text{P}\text{O}$ ratio is slightly diminished.     

Investigation of alkane biodegradation using the microtiter plate method and correlation between biofilm formation, biosurfactant production and crude oil biodegradation

Among 25 crude oil-degrading bacteria isolated from a marine environment, four strains, which grew well on crude oil, were selected for more study. All the four isolated had maximum growth on 2.5% of crude oil and strain BC (Pseudomonas) could remove crude oil by 83%. The drop collapse method and microtiter assay show that this strain produces more biosurfactant, and its biofilm formation is higher compared to other strains. Bacterial adhesions to crude oil for strains CS-2 (Pseudomonas), BC, PG-5 (Rhodococcus) and H (Bacillus) were 30%, 46%, 10% and 1%, respectively. Therefore, strain H with a low production of biosurfactant and biofilm formation had showed the least growth on these compounds. PCR analysis of these four strains showed that all isolates had alk-B genes from group (III) alkane hydroxylase. All isolate strains could utilize cyclohexan, octane, hexadecane, octadecan and diesel fuel oil; however, the microtiter plate assay showed that strain BC had more growth, respiration and biofilm formation on octadecan.     

Metabolic pathway optimization for biosynthesis of 1,2,4-butanetriol from xylose by engineered Escherichia coli

1,2,4-Butanetriol (BT) and related derivatives have been widely used in many fields, especially in the military and in medicine. In this paper, we systematically optimized the BT biosynthetic pathway. We first investigated the activities of various NADH dependent aldehyde reductases (ALRs), which catalyze the fourth reaction in the four-step pathway for BT production from xylose in E. coli, and found that a combination of multiple endogenous enzymes catalyzed aldehyde reduction in the BT production bioprocess and that YqhD in E. coli was a main ALR for BT production. In addition, ADH2 from Saccharomyces cerevisiae can effectively catalyze 3,4-dihydroxybutanal to BT. Also, YjhG was identified as the major xylonate dehydratase and was co-overexpressed with YqhD, resulting in an improvement of BT production by 30%. Moreover, we identified and eliminated the competing branch pathway by inactivating 2-keto acid reductases (yiaE). Finally, the combination of these approaches led to BT production of 5.1 g/L. In summary, our study provides insights into the biosynthetic pathway for BT production, demonstrates an effective strategy to enhance BT production, and paves the way toward in-depth research on BT biosynthesis.     

Assembly of a chimeric respiratory chain from bovine heart submitochondrial particles and cytochrome bd terminal oxidase of Escherichia coli

Cytochrome bd is a terminal quinol oxidase in Escherichia coli. Mitochondrial respiration is inhibited at cytochrome bc₁ (complex III) by myxothiazol. Mixing purified cytochrome bd oxidase with myxothiazol-inhibited bovine heart submitochondrial particles (SMP) restores up to 50% of the original rotenone-sensitive NADH oxidase and succinate oxidase activities in the absence of exogenous ubiquinone analogs. Complex III bypassed respiration and is saturated at amounts of added cytochrome bd similar to that of other natural respiratory components in SMP. The cytochrome bd tightly binds to the mitochondrial membrane and operates as an intrinsic component of the chimeric respiratory chain.     

降雨对旱作春玉米农田土壤呼吸动态的影响

土壤呼吸是调控全球碳平衡和气候变化的关键过程之一,降雨作为重要的扰动因子,在不同区域和不同环境条件下,对土壤呼吸具有复杂的影响.研究降雨对农田土壤呼吸及其分量的影响,对准确预测未来气候变化下陆地生态系统碳平衡具有重要意义.对黄土高原东部典型春玉米农田生态系统生长季内3次降雨前后土壤呼吸及其分量进行了原位连续观测,结果表明:在土壤湿润的条件下,降雨对春玉米农田土壤呼吸及其分量具有明显的抑制作用,在土壤湿度大于27％后土壤呼吸及其分量随土壤湿度上升呈明显下降,且对温度的敏感性降低.土壤呼吸及其分量在降雨前后的变化受土壤温度和土壤湿度的共同影响.降雨量、降雨历时和雨前土壤含水量决定了土壤呼吸及其分量对降雨响应的程度和时长.土壤呼吸及其分量对土壤温度的敏感性各不相同,微生物呼吸对温度的敏感性最高,Q10为5.14;其次是土壤呼吸,Q10为3.86;根呼吸的温度敏感性相对最低,Q10为3.24.由于土壤呼吸分量对温度和湿度的敏感性不同,降雨后根呼吸的比例有所升高.     

Effects of Essential Oils on Ruminal Microorganisms and Their Protein Metabolism

A commercial blend of essential oil (EO) compounds was added to a grass, maize silage, and concentrate diet fed to dairy cattle in order to determine their influence on protein metabolism by ruminal microorganisms. EO inhibited (P < 0.05) the rate of deamination of amino acids. Pure-culture studies indicated that the species most sensitive to EO were ammonia-hyperproducing bacteria and anaerobic fungi.     

Lysosomal acid proteinase of rabbit liver

1. The interference mechanism of carbonyl cyanide m-chlorophenylhydrazone with the respiratory process and with phosphorylation coupled to respiration has been investigated in resting cells of Escherichia coli. 2. Preincubation of the cells with carbonyl cyanide m-chlorophenylhydrazone in the absence of substrate caused strong inhibition of succinate oxidation. The inactivation of the respiratory system proved to be time-dependent and temperature-dependent and could be arrested by adding the substrate. Inhibition of incorporation of ³²P into acid-soluble organic phosphate esters exceeded the inhibition of oxygen uptake. 3. In contrast with succinate, the rate of oxidation of glucose was increased by carbonyl cyanide m-chlorophenylhydrazone. The sensitivity of other substrates to the inhibitor was less than that of succinate. 4. Various observations are described in support of the view that respiratory inhibition induced by carbonyl cyanide m-chlorophenylhydrazone is a result of its interference with ATP synthesis. The capacity of a given substrate to increase intracellular ATP concentration appeared to be directly related to its resistance to inhibition. In cell-free extracts carbonyl cyanide m-chlorophenylhydrazone still suppressed ³²P incorporation but had no effect on respiration. 5. Carbonyl cyanide m-chlorophenylhydrazone-induced stimulation of glucose oxidation and the acceleration of succinate oxidation by ADP or AMP in cells rendered permeable to nucleotides are tentatively interpreted as an indication that a certain part of respiration in E. coli is under phosphate-acceptor-mediated control.     

Dynamics of simple carbon compounds in two forest soils as revealed by soil solution concentrations and biodegradation kinetics

Simple compounds in soil such as organic acids, amino acids and monosaccharides are believed to be important in regulating many aspects of terrestrial ecosystem functioning (e.g. C cycling, nutrient acquisition). Understanding the fate and dynamics of these low molecular weight (MW) compounds is therefore essential for predicting ecosystem responses to disturbance. Our aim was to quantify the amounts of these compounds in two podzolic forest soil profiles (O, E, Bs and C horizons) and to quantify their contribution to total soil respiration. The total concentration of organic acids, amino acids and monosaccharides in soil solution comprised on average 15?±?10% of the total dissolved organic C (DOC), with declining concentrations in the deeper soil layers. Dissolved organic N (DON) was the dominant form of N in soil solution and free amino acids contributed to 34% of this pool. The mineralization behaviour of glucose and galactose was described by parabolic (Michaelis–Menten) type kinetics with V _max and K _M values in the range of <1–250 μmol kg^?1 h^?1 and 15–1,100 μM, respectively. Assuming that (1) microbially mediated substrate turnover follows Michaelis–Menten kinetics, and (2) steady state soil solution concentrations, we calculated the rate of CO₂ efflux attributable to the mineralisation of the three classes of low MW compounds. Our results indicated that in the O horizon, the turnover of these substrates could comprise ~100% of the basal, heterotrophic, soil respiration. In contrast, in the deeper mineral soil <20% of total soil respiration could be attributable to the mineralization of these compounds. Our compound-specific approach has identified the main substrates contributing to soil respiration in forest topsoils. However, our results also suggest that soil respiration in subsoils may be attributable to compounds other than organic acids, amino acids and monosaccharides.     

Systematic review and meta-analysis of the association between bridging therapy and outcomes of chimeric antigen receptor T cell therapy in patients with large B cell lymphoma

BackgroundThe existing evidence about the impact of bridging therapy (BT) on chimeric antigen receptor (CAR)-T cell therapy in patients with large B cell lymphoma (LBCL) is conflicting. Therefore, we reviewed all available evidence to examine the association between BT and CAR-T therapy outcomes by systematic review and meta-analysis approach.MethodsTwo reviewers independently searched Embase, PubMed, Web of Science, and Cochrane library to identify all records that described BT for LBCL treated with CAR-T. We then applied a fixed- or random-effects meta-analysis to estimate the pooled hazard ratios (HRs) and rate ratio (RRs) for efficacy and safety endpoints and assessed differences across various BT modalities. The Newcastle-Ottawa Scale was used to evaluate study quality.ResultsTwenty-six reports from 24 studies involving 2014 patients were included in the analysis. Pooled results showed that patients requiring BT had significantly worse 1-year overall survival rate (RR = 0.76, 95% confidence interval [CI] 0.68–0.85, P < 0.001), 1-year progression-free survival rate (RR = 0.71, 95% CI 0.60–0.85, P < 0.001), progression-free survival (HR = 1.35, 95% CI 1.07–1.69, P = 0.01), overall response rate (RR = 0.88, 95% CI 0.81–0.95, P = 0.001), complete response rate (RR = 0.78, 95% CI 0.65–0.93, P = 0.005), and grade ≥3 immune effector cell-associated neurotoxicity syndrome (RR = 1.43, 95% CI 1.10–1.87, P = 0.007), and tended to have poorer overall survival (HR = 1.42, 95% CI 0.99–2.02, P = 0.056) and grade ≥3 cytokine release syndrome (RR = 1.59, 95% CI 0.92–2.75, P = 0.096). Prolonged cytopenias were the common toxicity event associated with BT. Radiotherapy may serve as a promising BT option that can provide safe and effective disease control for patients with LBCL before CAR-T infusion. The inconsistency of patient baselines in the current study hindered further comparisons between different BT modalities. Most of the available evidence was rated as low quality because of concerns over low comparability.ConclusionBT appears to be associated with comparatively poor efficacy and safety outcomes after CAR-T infusion. However, due to the considerable heterogeneity between the BT and non-BT cohorts at disease baseline, no definitive conclusions can be made for the true impact of BT on CAR-T until further randomized studies are conducted.     

CYANIDE-SENSITIVE BACTERIAL RESPIRATORY SYSTEMS DIFFERENT FROM THE USUAL CYTOCHROME-CYTOCHROME OXIDASE SYSTEM

Aerobic respiration of Streptococcus pyogenes and pneumococcus Type 1 are strongly inhibited by KCN, NaN₃, and Na₂S. The anaerobic glycolysis of glucose by pneumococcus is also inhibited by KCN and NaN₃. Streptococcus pyogenes, E. coli, pneumococcus Type 1, B. subtilis, B. proteus, and Staphylococcus aureus did not catalyze the oxygen uptake by p-phenylenediamine in the presence of added cytochrome c or in its absence. Yeast cells, B. subtilis, and B. pyocyaneus oxidized p-phenylenediamine to a dark purple meriquinoid substance in contrast to the other bacteria mentioned above. Streptococcus pyogenes in contrast to pneumococcus Type 1 catalyzed the oxygen uptake by cysteine. Neither of these bacteria catalyzed the oxygen uptake by tyrosine, adrenaline, pyrocatechin, xanthine, and hypoxanthine. Streptococcus pyogenes, pneumococcus Type 1, and E. coli, boiled and not boiled, gave positive peroxidative tests with benzidine showing the presence of hematin compounds. The results discussed in the light of the interpretations offered by Keilin and Harpley show that Streptococcus pyogenes and pneumococcus Type 1 contain cyanide-sensitive respiratory systems which are different from the cytochrome c-cytochrome oxidase system.     

3,5-Diiodo-L-Thyronine Activates Brown Adipose Tissue Thermogenesis in Hypothyroid Rats

3,5-diiodo-l-thyronine (T2), a thyroid hormone derivative, is capable of increasing energy expenditure, as well as preventing high fat diet-induced overweight and related metabolic dysfunction. Most studies to date on T2 have been carried out on liver and skeletal muscle. Considering the role of brown adipose tissue (BAT) in energy and metabolic homeostasis, we explored whether T2 could activate BAT thermogenesis. Using euthyroid, hypothyroid, and T2-treated hypothyroid rats (all maintained at thermoneutrality) in morphological and functional studies, we found that hypothyroidism suppresses the maximal oxidative capacity of BAT and thermogenesis, as revealed by reduced mitochondrial content and respiration, enlarged cells and lipid droplets, and increased number of unilocular cells within the tissue. In vivo administration of T2 to hypothyroid rats activated BAT thermogenesis and increased the sympathetic innervation and vascularization of tissue. Likewise, T2 increased BAT oxidative capacity in vitro when added to BAT homogenates from hypothyroid rats. In vivo administration of T2 to hypothyroid rats enhanced mitochondrial respiration. Moreover, UCP1 seems to be a molecular determinant underlying the effect of T2 on mitochondrial thermogenesis. In fact, inhibition of mitochondrial respiration by GDP and its reactivation by fatty acids were greater in mitochondria from T2-treated hypothyroid rats than untreated hypothyroid rats. In vivo administration of T2 led to an increase in PGC-1α protein levels in nuclei (transient) and mitochondria (longer lasting), suggesting a coordinate effect of T2 in these organelles that ultimately promotes net activation of mitochondrial biogenesis and BAT thermogenesis. The effect of T2 on PGC-1α is similar to that elicited by triiodothyronine. As a whole, the data reported here indicate T2 is a thyroid hormone derivative able to activate BAT thermogenesis.     

BT2, a BTB Protein, Mediates Multiple Responses to Nutrients, Stresses, and Hormones in Arabidopsis

The Arabidopsis (Arabidopsis thaliana) gene BT2 encodes a 41-kD protein that possesses an amino-terminal BTB domain, a central TAZ domain, and a carboxyl-terminal calmodulin-binding domain. We previously demonstrated that BT2 could activate telomerase expression in mature Arabidopsis leaves. Here, we report its distinct role in mediating diverse hormone, stress, and metabolic responses. We serendipitously discovered that steady-state expression of BT2 mRNA was regulated diurnally and controlled by the circadian clock, with maximum expression in the dark. This pattern of expression suggested that BT2 mRNA could be linked to the availability of photosynthate in the plant. Exogenous sugars decreased BT2 expression, whereas exogenous nitrogen increased expression. bt2 loss-of-function mutants displayed a hypersensitive response to both sugar-mediated inhibition of germination and abscisic acid (ABA)-mediated inhibition of germination, thus supporting a role of ABA in sugar signaling in germination and development. Moreover, constitutive expression of BT2 imparted resistance to both sugars and ABA at germination, suggesting that BT2 suppresses sugar and ABA responses. In support of the previously described antagonistic relationship between ABA and auxin, we found that BT2 positively regulated certain auxin responses in plants, as revealed by knocking down BT2 expression in the high-auxin mutant yucca. Accumulation of BT2 mRNA was affected by a variety of hormones, nutrients, and stresses, and BT2 was required for responses to many of these same factors. Together, these results suggest that BT2 is a central component of an interconnected signaling network that detects and responds to multiple inputs.     

The use of the normal tissue non-complication probability (NTCP0) methodology as a new alternative of assessing side-effects in brachytherapy treatments

BackgroundThe NTCP methodology evaluating side-effects (S-Es) was initially used in radiotherapy (RT), and later was extended to brachytherapy (BT). The NTCP0 methodology has been recently introduced in RT. Given the advantages, this methodology could replace NTCP.Materials and methodsRevisions of studies related to use of NTCP in the evaluations of S-Es in BT. Development of the first versions of two Matlab applications of the NTCP0 methodology. These applications have three options. Two of them employ the well-known aspects of a phenomenological model, or the probabilistic relationship between NTCP0 and total NTCP (TNTCP) that is the sum(NTCP(x_i)) i: i^th complication i:1..nc: Number of complications; where NTCP0 = 100% — TNTCP; and the third option assumes a NTCP(x_i) discrete probabilistic distribution generated by the binomial distribution, where one of its parameters is automatically obtained from a databased of the Disease locations Vs. Late complications.ResultsThe NTCP0cal and NTCP0calDr Matlab applications have been developed, and respectively used for fractional continuous low dose-rate BT.ConclusionsNTCP0 is defined as the ratio of the number of patients without acute/late complications and total of them, and also can be obtained using our Matlab applications. NTCP0 works do not disregard the last 10–15 years of NTCP research; but NTCP0 was not considered during these years. A generic example was used for showing the variations of the late complications and NTCP0 for a BT treatment of a constant number of fractions and six different dose per fraction values.     

Effects of lipids and related compounds on the production of halophilic 5′-nucleotidase and nuclease H by a moderate halophile,Micrococcus varians subsp. halophilus

The effects of lipids and related compounds on the production of halophilic 5′-nucleotidase and nuclease H by a moderate halophile, Micrococcus varians subsp. halophilus were examined. In order to increase the yield of flavoring 5′-nucleotide production from RNA using crude enzyme solution containing 5′-nucleotidase as well as nuclease H, the selective prevention of 5′-nucleotidase production is necessary. Addition of 0.5 to 1.0% whale oil was found to be fairly effective for the purpose, giving about 72 to 84% prevention. Tripalmitin, triolein and ethyllaurate also showed similar high levels of selective prevention. As it is known that whale oil contains relatively high percentages of palmitate and oleate, its effect seems to be partly attributable to the high content of these esters.     

Improved 1, 2, 4-butanetriol production from an engineered <Emphasis Type="Italic">Escherichia coli</Emphasis> by co-expression of different chaperone proteins

1, 2, 4-Butanetriol (BT) is a high-value non-natural chemical and has important applications in polymers, medical production and military industry. In the constructed BT biosynthesis pathway from xylose in Escherichia coli, the xylose dehydrogenase (Xdh) and the benzoylformate decarboxylase (MdlC) are heterologous enzymes and the activity of MdlC is the key limiting factor for BT production. In this study, six chaperone protein systems were introduced into the engineered E. coli harboring the recombinant BT pathway. The chaperone GroES–GroEL was beneficial to Xdh activity but had a negative effect on MdlC activity and BT titer. The plasmid pTf16 containing the tig gene (trigger factor) was beneficial to Xdh and MdlC activities and improved the BT titer from 0.42 to 0.56 g/l from 20 g/l xylose. However, co-expression of trigger factor and GroES–GroEL simultaneously reduced the activity of MdlC and had no effect on the BT production. The plasmid pKJE7 harboring dnaK–dnaJ–grpE showed significant negative effects on these enzyme activities and cell growth, leading to completely restrained the BT production. Similarly, co-expression of DnaKJ–GrpPE and GroES–GroEL simultaneously reduced Xdh and MdlC activities and decreased the BT titer by 45.2 %. The BT production of the engineered E. coli harboring pTf16 was further improved to the highest level at 1.01 g/l under pH control (pH 7). This work showed the potential application of chaperone proteins in microorganism engineering to get high production of target compounds as an effective and valuable tool.     

Essential oil composition of Eryngium rosulatum P.W. Michael ined.: A new undescribed species from eastern Australia

The essential oil composition from the aerial parts of a new Eryngium species from Australia, Eryngium rosulatum P.W. Michael ined., has been analysed by GC and GC/MS. A total of 34 compounds have been identified representing around 80% of the total oil. The main constituents of the oil were found to be β-elemene (16.0%) and bicyclogermacrene (12.5%). Other representative compounds were identified as δ-elemene (7.0%) and (E)-caryophyllene (5.9%). The sesquiterpene fraction (75.0%) was predominant in the essential oil of this species, most of these were hydrocarbons (53.8%). This paper represents the first study on this new, undescribed Australian species and its chemical composition.