Natural foci of the Moroccan locust (<Emphasis Type="Italic">Dociostaurus maroccanus</Emphasis>, Orthoptera,Acrididae) in Turkmenistan and their current state

The current state of natural foci and the population dynamics of the Moroccan locust Dociostaurus maroccanus in Turkmenistan are described. The slope aspect, micro-relief, plant cover condition, and the degree of anthropogenic impact were considered in natural landscapes. The locations of the natural foci were described using a Garmin eTrex GPS device. The causes and features of changes in the altitudinal and latitudinal distribution of the species’ natural foci in the Kopet Dagh and Koyten Dagh mountains during the second half of the XX and early XXI centuries are revealed. Both lower and upper range limit extensions of the locust foci are shown to have been due to xerophytization of the mountain ecosystems because of excessive pasture use and climate aridization. As a result, Turkmenistan presently supports 15 areas of D. maroccanus outbreaks instead of 12 areas known previously.     

The eurythermal adaptivity and temperature tolerance of a newly isolated psychrotolerant Arctic <Emphasis Type="Italic">Chlorella</Emphasis> sp.

A new strain of Chlorella sp. (Chlorella-Arc), isolated from Arctic glacier melt water, was found to have high specific growth rates (μ) between 3 and 27 °C, with a maximum specific growth rate of 0.85 day^?1 at 15 °C, indicating that this strain was a eurythermal strain with a broad temperature tolerance range. To understand its acclimation strategies to low and high temperatures, the physiological and biochemical responses of the Chlorella-Arc to temperature were studied and compared with those of a temperate Chlorella pyrenoidosa strain (Chlorella-Temp). As indicated by declining F _v/F _m, photoinhibition occurred in Chlorella-Arc at low temperature. However, Chlorella-Arc reduced the size of the light-harvesting complex (LHC) to alleviate photoinhibition, as indicated by an increasing Chl a/b ratio with decreasing temperatures. Interestingly, Chlorella-Arc tended to secrete soluble sugar into the culture medium with increasing temperature, while its intracellular soluble sugar content did not vary with temperature changes, indicating that the algal cells might suffer from osmotic stress at high temperature, which could be adjusted by excretion of soluble sugar. Chlorella-Arc accumulated protein and lipids under lower temperatures (<15 °C), and its metabolism switched to synthesis of soluble sugar as temperatures rose. This reflects a flexible ability of Chlorella-Arc to regulate carbon and energy distribution when exposed to wide temperature shifts. More saturated fatty acids (SFA) in Chlorella-Arc than Chlorella-Temp also might serve as the energy source for growth in the cold and contribute to its cold tolerance.     

Hypocrealean fungi associated with populations of <Emphasis Type="Italic">Ips typographus</Emphasis> in West Carpathians and selection of local <Emphasis Type="Italic">Beauveria</Emphasis> strains for effective bark beetle control

In Slovakia, a diversity of entomopathogenic fungi (Ascomycota, Hypocreales) associated with outbreaks of Ips typographus was studied in 81 localities and as many as 113 in vitro cultures of five entomopathogenic species were isolated from infected individuals: Beauveria bassiana (87 isolates), B. pseudobassiana (14 isolates), B. caledonica (6 isolates), Lecanicillium lecanii (4 isolates) and Isaria farinosa (2 isolates). B. pseudobassiana is recorded in natural populations of I. typographus for the first time. Biological properties of selected Beauveria isolates, including colony growth, biomass production, conidia yield and pathogenicity to I. typographus adults, were studied in a series of laboratory bioassays and much intra- and interspecific variability was detected. B. bassiana isolates produced biomass or conidia at significantly higher rate than B. pseudobassiana and B. caledonica isolates. Two B. bassiana isolates were selected as the most virulent to bark beetle adults, demonstrating a mean LC₅₀ ranging from 0.72 to 2.05?×?10⁶ conidia ml^?1, and were qualified as promising candidates for biocontrol of I. typographus. Their virulence was significantly higher than that of the mycoinsecticides Boverol®, which was used as a reference strain in the virulence bioassays.     

Usefulness of the Non-conventional <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis> Model to Assess <Emphasis Type="Italic">Candida</Emphasis> Virulence

Invasive candidiasis is caused mainly by Candida albicans, but other Candida species have increasing etiologies. These species show different virulence and susceptibility levels to antifungal drugs. The aims of this study were to evaluate the usefulness of the non-conventional model Caenorhabditis elegans to assess the in vivo virulence of seven different Candida species and to compare the virulence in vivo with the in vitro production of proteinases and phospholipases, hemolytic activity and biofilm development capacity. One culture collection strain of each of seven Candida species (C. albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida metapsilosis, Candida orthopsilosis and Candida parapsilosis) was studied. A double mutant C. elegans AU37 strain (glp-4;sek-1) was infected with Candida by ingestion, and the analysis of nematode survival was performed in liquid medium every 24 h until 120 h. Candida establishes a persistent lethal infection in the C. elegans intestinal tract. C. albicans and C. krusei were the most pathogenic species, whereas C. dubliniensis infection showed the lowest mortality. C. albicans was the only species with phospholipase activity, was the greatest producer of aspartyl proteinase and had a higher hemolytic activity. C. albicans and C. krusei caused higher mortality than the rest of the Candida species studied in the C. elegans model of candidiasis.     

<Emphasis Type="Italic">Novosphingobium profundi</Emphasis> sp. nov. isolated from a deep-sea seamount

A marine bacterial strain, F72^T, was isolated from a solitary scleractinian coral, collected in Yap seamounts in the Pacific Ocean. Strain F72^T is a Gram-negative, light-yellow-pigmented, motile, rod-shaped bacterium. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain F72^T is related to the genus Novosphingobium and has high 16S rRNA gene sequence similarities with the type strains of Novosphingobium pentaromativorans US6-1^T (97.7 %), Novosphingobium panipatense SM16^T (97.6 %), Novosphingobium mathurense SM117^T (97.2 %) and Novosphingobium barchaimii LL02^T (97.1 %). Ubiquinone Q-10 was detected as the dominant quinone. The predominant cellular fatty acids were C_18:1ω7c and C_17:1ω6c. The genomic DNA G+C content of strain F72^T was 63.4 mol %. The polar lipids profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylcholine, sphingoglycolipid and one uncharacterized lipid. Strain F72^T shared DNA relatedness of 25 % with N. pentaromativorans JCM 12182^T, 31 % with N. panipatense DSM 22890^T, 21 % with N. mathurense DSM 23374^T and 26 % with N. barchaimii DSM 25411^T. Combined data from phenotypic, phylogenetic and DNA–DNA relatedness studies demonstrated that the strain F72^T is a representative of a novel species of the genus Novosphingobium, for which we propose the name Novosphingobium profundi sp. nov. (type strain F72^T = KACC 18566^T = CGMCC 1.15390^T).     

<Emphasis Type="Italic">Rubricella aquisinus</Emphasis> gen. nov., sp. nov., a novel member of the family <Emphasis Type="Italic">Rhodobacteraceae</Emphasis>

A Gram-stain negative, ovoid or short rod-shaped, aerobic and non-motile bacterial strain, designated J82^T, was isolated from a seawater sample collected from the coast of Yellow Sea in Qingdao, China. The strain grew at salinities of 1.0–6.0% (w/v) NaCl (optimum, 2.5%). Growth occurred at pH 6.0-8.0 (optimum, pH 7.0) and 10–42 °C (optimum, 28–30 °C). The genomic DNA G + C content was determined to be 57.5 mol%. Q-10 was detected as the respiratory quinone. The major fatty acid (>10%) was Summed feature 8 (C_18:1 ω7c and/or C_18:1 ω6c). The polar lipids consisted of phosphatidylethanolamine, two unidentified aminolipids and two unidentified polar lipids. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain J82^T forms a distinct evolutionary lineage within the family Rhodobacteraceae. On the basis of phenotypic, chemotaxonomic and phylogenetic characteristics, the strain merits recognition as representative of a novel genus and species within the family Rhodobacteraceae for which the name Rubricella aquisinus gen. nov., sp. nov. is proposed. The type strain of Rubricella aquisinus is J82^T (= DSM 103377^T = CCTCC AB 2016170^T).     

<Emphasis Type="Italic">Paradevosia shaoguanensis</Emphasis> gen. nov., sp. nov., Isolated from a Coking Wastewater

A Gram staining negative, rod-shaped, aerobic bacterial strain J5-3^T with a single polar flagellum was isolated from coking wastewater collected from Shaoguan, Guangdong, China. It was motile and capable of optimal growth at pH 6–8, 30 °C, and 0–2 % (w/v) NaCl. Its predominant fatty acids were 11-methyl C_18:1 ω7c (29.2 %), C_16:0 (20.6 %), C_19:0 cyclo ω8c (18.2 %), C_18:0 (11.0 %), and C_18:1 ω7c/C_18:1 ω6c (10.9 %) when grown on trypticase soy agar. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, two unknown glycolipids (GL1, GL2), and two unknown phospholipid (PL1, PL2). The predominant ubiquinone was Q-10, and the genome DNA G+C content was 61.7 mol %. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain J5-3^T belonged to the family Hyphomicrobiaceae in Alphaproteobacteria. It shared the 16S rRNA gene sequence similarities of 93.8–96.1 % with the genus Devosia, 94.5–94.8 % with the genus Pelagibacterium, and <92.0 % with all the other type strains in family Hyphomicrobiaceae. It can be distinguished from the closest phylogenetic neighbors based on several phenotypic and genotypic features, including α-galactosidase activity, tetracycline susceptibility, major fatty acid composition, polar lipid profile, DNA gyrase B subunit (gyrB) gene sequence, and random-amplified polymorphic DNA profile. Therefore, we consider strain J5-3^T to represent a novel species of a novel genus within the family Hyphomicrobiaceae, for which the name Paradevosia shaoguanensis gen. nov., sp. nov. is proposed. The type strain of Paradevosia shaoguanensis is J5-3^T (=CGMCC 1.12430^T =LMG 27409^T).     

Simultaneous removal of hexavalent chromium and <Emphasis Type="Italic">o</Emphasis>-dichlorobenzene by isolated <Emphasis Type="Italic">Serratia marcescens</Emphasis> ZD-9

Heavy metals–organics mixture pollution is increasingly concerned and simultaneous removal of organic pollutants and heavy metals is becoming significant. In this study, a strain was isolated from the sediment of a tannery effluent outfalls, which can remove o-dichlorobenzene (o-DCB) and Cr(VI) simultaneously. The bacterial isolate was identified as Serratia marcescens by the 16S rRNA gene sequences. The strain removed about 90% of o-DCB and more than 80% of Cr(VI) at the concentration of 1.29 g L^?1 o-DCB and 20 mg L^?1 Cr(VI). In the presence of concomitant pollutant o-DCB, the optimal pH (8.0) and temperature (30 °C) were determined for Cr(VI) removal. Changes of the bacterial cells and intracellular black Cr(III) sediments were observed by the TEM auxiliary analysis. The results of the FTIR spectroscopy analysis indicated that hydroxyl, amide and polysaccharides were involved in the process of Cr(VI) removal.     

Improving biocontrol of black vine weevil (<Emphasis Type="Italic">Otiorhynchus sulcatus</Emphasis>) with entomopathogenic fungi in growing media by incorporating spent mushroom compost

Amending a peat-based growing medium with 10% v/v spent mushroom compost, a source of fungal chitin and other nutrients, prolonged the persistence of entomopathogenic fungi (Metarhizium brunneum Petsch and Beauveria bassiana (Balsamo) Vuillemin; Hypocreales: Clavicipitaceae). This resulted in improved efficacy of M. brunneum against black vine weevil, Otiorhynchus sulcatus F. (Coleoptera: Curculionidae) larvae compared with using inoculum without spent mushroom compost. B. bassiana only controlled larvae when used in combination with spent mushroom compost (75?±?7% reduction in live larvae). Mixing entomopathogenic fungal inoculum with spent mushroom compost and growing medium was as effective in controlling black vine weevil larvae as using spent mushroom compost colonised with M. brunneum or B. bassiana in the growing medium (80?±?12% reduction in live larvae). The former method is preferable since it does not require production and storage of colonised spent mushroom compost, or registration of new substrate formulations of M. brunneum or B. bassiana.     

Enhancement of NAD(H) pool for formation of oxidized biochemicals in <Emphasis Type="Italic">Escherichia coli</Emphasis>

The NAD⁺/NADH ratio and the total NAD(H) play important roles for whole-cell biochemical redox transformations. After the carbon source is exhausted, the degradation of NAD(H) could contribute to a decline in the rate of a desired conversion. In this study, methods to slow the native rate of NAD(H) degradation were examined using whole-cell Escherichia coli with two model oxidative NAD⁺-dependent biotransformations. A high phosphate concentration (50 mM) was observed to slow NAD(H) degradation. We also constructed E. coli strains with deletions in genes coding several enzymes involved in NAD⁺ degradation. In shake-flask experiments, the total NAD(H) concentration positively correlated with conversion of xylitol to l-xylulose by xylitol 4-dehydrogenase, and the greatest conversion (80%) was observed using MG1655 nadR nudC mazG/pZE12-xdh/pCS27-nox. Controlled 1-L batch processes comparing E. coli nadR nudC mazG with a wild-type background strain demonstrated a 30% increase in final l-xylulose concentration (5.6 vs. 7.9 g/L) and a 25% increase in conversion (0.53 vs. 0.66 g/g). MG1655 nadR nudC mazG was also examined for the conversion of galactitol to l-tagatose by galactitol 2-dehydrogenase. A batch process using 15 g/L glycerol and 10 g/L galactitol generated over 9.4 g/L l-tagatose, corresponding to 90% conversion and a yield of 0.95 g l-tagatose/g galactitol consumed. The results demonstrate the value of minimizing NAD(H) degradation as a means to improve NAD⁺-dependent biotransformations.     

Biological Data on <Emphasis Type="Italic">Anovia punica</Emphasis> Gordon (Coleoptera: Coccinellidae), a Predator of <Emphasis Type="Italic">Crypticerya multicicatrices</Emphasis> Kondo &amp; Unruh (Hemiptera: Monophlebidae)

The coccinellid beetle Anovia punica Gordon (Coleoptera: Coccinellidae: Noviini) is an important predator of the Colombian fluted scale, Crypticerya multicicatrices Kondo & Unruh (Hemiptera: Monophlebidae). In order to gather information on the biological traits of A. punica, we conducted a series of studies, including of the developmental time of each life history stage, estimation of life table parameters, and predation rates under laboratory conditions [25.1 ± 1.6°C, with 70.5 ± 7.3% RH, and natural light regime, approx. 12:12 (L:D) h]. Developmental stages of A. punica were categorized as follows: egg stage, four larval instars, prepupal instar, pupal instar, and adult. Developmental time from egg to adult emergence averaged 29.41 ± 1.85 days, and 47.6% of the eggs developed to adulthood. Female and male survival was 94.42 and 90 days, respectively. Life table parameters show that one female of A. punica is replaced by 86 females (R ₀), the intrinsic growth rate (r _m ) was 0.1115, the average generation time (T) was 40 days, and the doubling time (D _t ) was 6.2 days. The life table parameters suggest that A. punica can be used as a potential predator of C. multicicatrices and, more importantly, provided baseline information for a mass-rearing protocol. This is the first detailed study on the biology of A. punica that reports the potential of this predator as a biological control agent for scale insects of the tribe Iceryini.     

The <Emphasis Type="Italic">yajC</Emphasis> gene from <Emphasis Type="Italic">Lactobacillus buchneri</Emphasis> and <Emphasis Type="Italic">Escherichia coli</Emphasis> and its role in ethanol tolerance

The yajC gene (Lbuc_0921) from Lactobacillus buchneri NRRL B-30929 was identified from previous proteomics analyses in response to ethanol treatment. The YajC protein expression was increased by 15-fold in response to 10 % ethanol vs 0 % ethanol. The yajC gene encodes the smaller subunit of the preprotein translocase complex, which interacts with membrane protein SecD and SecF to coordinate protein transport and secretion across cytoplasmic membrane in Escherichia coli. The YajC protein was linked to sensitivity to growth temperatures in E. coli, involved in translocation of virulence factors during Listeria infection, and stimulating a T cell-mediated response of Brucella abortus. In this study, the L. buchneri yajC gene was over-expressed in E. coli. The strain carrying pET28byajC that produces YajC after isopropyl β-d-1-thiogalactopyranoside induction showed tolerance to 4 % ethanol in growth media, compared to the control carrying pET28b. This is the first report linking YajC to ethanol stress and tolerance.     

<Emphasis Type="Italic">Deinococcus knuensis</Emphasis> sp. nov., a bacterium isolated from river water

Strain 16F3H^T, a Gram-negative, aerobic, non-motile, and oval-shaped bacterium, was isolated from river water collected from the Han River in South Korea. Growth of strain 16F3H^T was observed at 10–42 °C (optimum at 25–30 °C), but no growth occurred at 4 °C. The strain is able to grow at pH 4–10 (optimum at pH 7–8) and tolerates up to 4% NaCl (w/v), with optimum growth at 0.5% NaCl. The isolate was found to be resistant to UV irradiation. Based on 16S rRNA gene sequence analysis, it is closely related to ‘Deinococcus seoulensis’ 16F1E (98.8%), Deinococcus aquaticus PB314^T (98.1%) and Deinococcus caeni Ho-08^T (98.0%). The level of DNA–DNA homology between the novel strain and the three related strains was 57.4, 41.2, and 35.8%, respectively. Chemotaxonomic data revealed that strain 16F3H^T possesses MK-8 as the predominant respiratory quinone, an unidentified phosphoglycolipid as the major polar lipid, and C_15:1 ω6c and C_16:1 ω7c as the major fatty acids. The DNA G + C content was determined to be 65.7 mol%. Based on polyphasic evidence, strain 16F3H^T (=KCTC 33794^T = JCM 31406^T) should be classified as the type strain of a novel Deinococcus species, for which the name Deinococcus knuensis sp. nov. is proposed.     

Layer-specific strain analysis in patients with suspected stable angina pectoris and apparently normal left ventricular wall motion

Background

Non-invasive imaging tests are widely used in the evaluation of stable angina pectoris (SAP). Despite these tests, non-significant coronary lesions are not a rare finding in patients undergoing elective coronary angiography (CAG). Two-dimensional (2D) speckle tracking global longitudinal strain (GLS) imaging is a more sensitive and accurate technique for measuring LV function than conventional 2D methods. Layer-specific strain analysis is a relatively new method that provides endocardial and epicardial myocardial layer assessment. The aim of the present study was to evaluate longitudinal layer-specific strain (LSS) imaging in patients with suspected SAP.

Methods

Patients who underwent CAG for SAP were retrospectively screened. A total of 79 patients with no history of heart disease and wall motion abnormalities were included in the study. Forty-three patients with coronary lesions >?70% constituted the coronary artery disease (CAD) group and 36 patients without significant CAD constituted the control group. Layer-specific GLS transmural, endocardium, and epicardium values (GLS-trans, GLS-endo, and GLS-epi, respectively) were compared between the groups.

Results

Patients in the CAD group had significantly lower GLS values in all layers (GLS-trans: -18.2 + 2.4% vs -22.2 + 2.2% p?<?.001; GLS-endo: -20.8 + 2.8% vs -25.3 + 2.6%, p?<?.001; GLS-epi: 15.9 + 2.4% vs -19.5 + 1.9%, p?<?.001). Multivariate adjustment demonstrated GLS-trans as the only independent predictor of CAD [OR:0.472, CI (0.326–0.684), p?<?.001]. Additionally, the GLS values were all lower in myocardial perfusion scintigraphy (MPS) true-positive patients compared with MPS false-positive patients (GLS-trans: -17.7?±?2.4 vs. -21.9?±?2.4%, p?<?.001; GLS-endo: -20.2?±?2.9% vs -24.9?±?2.9%, P?<?.001; GLS-epi: 15.4?±?2.6% vs. -19.2?±?1.8%, P?<?.001).

Conclusion

Resting layer-specific strain as assessed by 2D speckle tracking analysis demonstrated that GLS values were reduced in all layers of myocardium with SAP and with no wall motion abnormalities. LSS analysis can improve the identification of patients with significant CAD but further prospective larger scale studies are needed to put forth the incremental value of LSS analysis over transmural GLS.

     

Cold stress promoting a psychrotolerant bacterium <Emphasis Type="Italic">Pseudomonas</Emphasis><Emphasis Type="Italic">fragi</Emphasis> P121 producing trehaloase

A newly isolated Pseudomonas fragi P121 strain in a soil sample taken from the Arctic Circle is able to produce trehalose. The P121 strain was able to grow at temperatures ranging from 4 to 25 °C, had an optimum pH of 6.5, and an optimum salt concentration of 2 %. The P121 strain had a survival rate of 29.1 % after being repeatedly frozen and thawed five times, and a survival rate of 78.9 % when placed in physiological saline for 15 days at 20 °C after cold shock, which is far higher than the type strain Pseudomonas fragi ATCC 4973. The P121 strain could produce 2.89 g/L trehalose, which was 18.6 % of dry cell weight within 52 h in a 25 L fermention tank using the malt extract prepared from barley as medium at 15 °C, while only 11.8 % of dry cell weight at 20 °C. These results suggested that cold stress promoted the strain producing trehalose. It is the first reported cold-tolerant bacterium that produces trehalose, which may protect cells against the cold environment.     

Biodegradation of sulfonamides by <Emphasis Type="Italic">Shewanella oneidensis</Emphasis> MR-1 and <Emphasis Type="Italic">Shewanella</Emphasis> sp. strain MR-4

Because of extensive sulfonamides application in aquaculture and animal husbandry and the consequent increase in sulfonamides discharged into the environment, strategies to remediate sulfonamide-contaminated environments are essential. In this study, the resistance of Shewanella oneidensis MR-1 and Shewanella sp. strain MR-4 to the sulfonamides sulfapyridine (SPY) and sulfamethoxazole (SMX) were determined, and sulfonamides degradation by these strains was assessed. Shewanella oneidensis MR-1 and Shewanella sp. strain MR-4 were resistant to SPY and SMX concentrations as high as 60 mg/L. After incubation for 5 days, 23.91 ± 1.80 and 23.43 ± 2.98% of SPY and 59.88 ± 1.23 and 63.89 ± 3.09% of SMX contained in the medium were degraded by S. oneidensis MR-1 and Shewanella sp. strain MR-4, respectively. The effects of the initial concentration of the sulfonamides and initial pH of the medium on biodegradation, and the degradation of different sulfonamides were assessed. The products were measured by LC–MS; with SPY as a substrate, 2-AP (2-aminopyridine) was the main stable metabolite, and with SMX as a substrate, 3A5MI (3-amino-5-methyl-isoxazole) was the main stable metabolite. The co-occurrence of 2-AP or 3A5MI and 4-aminobenzenesulfonic acid suggests that the initial step in the biodegradation of the two sulfonamides is S–N bond cleavage. These results suggest that S. oneidensis MR-1 and Shewanella sp. strain MR-4 are potential bacterial resources for biodegrading sulfonamides and therefore bioremediation of sulfonamide-polluted environments.     

Very high gravity ethanol and fatty acid production of <Emphasis Type="Italic">Zymomonas mobilis</Emphasis> without amino acid and vitamin

Very high gravity (VHG) fermentation is the mainstream technology in ethanol industry, which requires the strains be resistant to multiple stresses such as high glucose concentration, high ethanol concentration, high temperature and harsh acidic conditions. To our knowledge, it was not reported previously that any ethanol-producing microbe showed a high performance in VHG fermentations without amino acid and vitamin. Here we demonstrate the engineering of a xylose utilizing recombinant Zymomonas mobilis for VHG ethanol fermentations. The recombinant strain can produce ethanol up to 136 g/L without amino acid and vitamin with a theoretical yield of 90 %, which is significantly superior to that produced by all the reported ethanol-producing strains. The intracellular fatty acids of the bacterial were about 16 % of the bacterial dry biomass, with the ratio of ethanol:fatty acids was about 273:1 (g/g). The recombinant strain was achieved by a multivariate-modular strategy tackles with the multiple stresses which are closely linked to the ethanol productivity of Z. mobilis. The over-expression of metB/yfdZ operon enabled the growth of the recombinant Z. mobilis in a chemically defined medium without amino acid and vitamin; and the fatty acids overproduction significantly increased ethanol tolerance and ethanol production. The coupled production of ethanol with fatty acids of the Z. mobilis without amino acid and vitamin under VHG fermentation conditions may permit a significant reduction of the production cost of ethanol and microbial fatty acids.     

Growth kinetics and scale-up of <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

Production of recombinant proteins in plants through Agrobacterium-mediated transient expression is a promising method of producing human therapeutic proteins, vaccines, and commercial enzymes. This process has been shown to be viable at a large scale and involves growing large quantities of wild-type plants and infiltrating the leaf tissue with a suspension of Agrobacterium tumefaciens bearing the genes of interest. This study examined one of the steps in this process that had not yet been optimized: the scale-up of Agrobacterium production to sufficient volumes for large-scale plant infiltration. Production of Agrobacterium strain C58C1 pTFS40 was scaled up from shake flasks (50–100 mL) to benchtop (5 L) scale with three types of media: Lysogeny broth (LB), yeast extract peptone (YEP) media, and a sucrose-based defined media. The maximum specific growth rate (μ _max) of the strain in the three types of media was 0.46 ± 0.04 h^?1 in LB media, 0.43 ± 0.03 h^?1 in YEP media, and 0.27 ± 0.01 h^?1 in defined media. The maximum biomass concentration reached at this scale was 2.0 ± 0.1, 2.8 ± 0.1, and 2.6 ± 0.1 g dry cell weight (DCW)/L for the three media types. Production was successfully scaled up to a 100-L working volume reactor with YEP media, using k _L a as the scale-up parameter.     

<Emphasis Type="Italic">Braf</Emphasis>, <Emphasis Type="Italic">Kras</Emphasis> and <Emphasis Type="Italic">Helicobacter pylori</Emphasis> epigenetic changes-associated chronic gastritis in Egyptian patients with and without gastric cancer

We aimed to study MLH1 and MGMT methylation status in Helicobacter pylori-associated chronic gastritis in Egyptian patients with and without gastric cancer. 39 patients were included in our study. They were divided into 2 groups; patients without (group I) and with gastric adenocarcinoma (group II). Patients were subjected to clinical examination, abdominal ultrasound and upper endoscopy for gastric biopsy. Biopsies were subjected to urease test, histological examination, and DNA purification. H. pylori, Braf, Kras, MLH1 and MGMT methylation were assessed by quantitative PCR. DNA sequencing was performed to assess Braf and Kras genes mutation. qPCR of H. pylori was significantly higher in patients with adenocarcinoma (group II) than those without adenocarcinoma (group I); with a p < 0.001 as well as in patients with age above 50 years with a p value = 0.008. By applying logistic regression analysis it was reported that the H. pylori qPCR is a significant predictor to the adenocarcinoma with OR = 1.025 (95 % CI: 1. 002–1.048), with sensitivity of 90 % and specificity of 100 %. Adenocarcinoma patients had a significantly higher mean age and levels of H. Pylori, Braf, K-ras, methylated MGMT and methylated MLH1 than those of gastritis patients. DNA sequence analysis of Braf (codon 12) and Kras (codon 600) had genes mutation in gastric adenocarcinoma versus chronic gastritis. Conclusion: H. pylori may cause epigenetic changes predisposing the patients to cancer stomach. Estimation of H. pylori by qPCR can be a good predictor to adenocarcinoma. Braf and Kras genes mutation were reveled in gastritis and adenocarcinoma patients.     

Leaf Extracts of Selected Gardening Trees Can Attenuate Quorum Sensing and Pathogenicity of <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> PAO1

An increasing concern on resistance to multiple-antibiotics has led to the discovery of novel agents and the establishment of new precaution strategy. Numerous plant sources have been widely studied to reduce virulence of pathogenic bacteria by interfering cell-to-cell based communication called quorum sensing (QS). Leaf extracts of 17 gardening trees were collected and investigated for their anti-QS effects using a sensor strain Chromobacterium violaceum CV026. Methanolic extracts of K4 (Acer palmatum), K9 (Acer pseudosieboldianum) and K13 (Cercis chinensis) leaves were selected for further experiments based on their antagonism effect on QS without inhibiting C. violaceum CV026 growth. Subsequently, the leaf extracts on QS-mediated virulence of Pseudomonas aeruginosa PAO1 involved in biofilm formation, motility, bioluminescence, pyocyanin production, QS molecules production, and Caenorhabditis elegans killing activity were evaluated. The biofilm formation ability and swarming motility of P. aeruginosa PAO1 were decreased approximately 50% in the presence of these leaf extracts at a concentration of 1 mg/mL. The expression level of lecA::lux of P. aeruginosa PAO1 and pyocyanin production were also reduced. The three leaf extracts also decreased autoinducer (AI) production in P. aeruginosa PAO1 without direct degradation, suggesting that AI synthesis might have been suppressed by these extracts. The three leaf extracts also showed anti-infection activity in C. elegans model. Taken together, these results suggest that methanolic leaf extracts of K4, K9 and K13 have the potential to attenuate the virulence of P. aeruginosa PAO1.