Pseudomonas 42P4 and Cellulosimicrobium 60I1 as a sustainable approach to increase growth, development, and productivity in pepper plants

The production of pepper plants for industrial use is not enough to satisfy the demand of consumers and agrochemicals are frequently used to increase production. In this study four native plant growth promoting rhizobacteria (PGPR) was tested as an alternative to select the most effective to enhance growth, development, and productivity of pepper plants. Seedlings were inoculated with Pseudomonas 42P4, Cellulosimicrobium 60I1, Ochrobactrum 53F, Enterobacter 64S1 and cultivated on pots in the greenhouse and the morphological, biochemical, and physiological parameters were determined. In addition, the phenolic compound profiles were evaluated. All four strains increased the different parameters evaluated but Pseudomonas 42P4 and Cellulosimicrobium 60I1 were the most effective strains, improving leaf and root dry weight, stem diameter, nitrogen level, stomatal conductance, chlorophyll quantum efficiency, chlorophyll SPAD index, total chlorophyll and carotenoid levels, number of flowers and fruits per plant, and the length, diameter and dry weight of the fruit. Also, these strains modified the phenolic compound profiles, and 18 compounds were quantified. Pseudomonas 42P4 inoculation modified the phenolic compound profile similarly to the Fertilized treatment and induced the synthesis of different endogenous compounds in the flavonoid family, also increasing catechin, naringin, naringenin, myricetin, procyanidin B1, epigallocatechin-gallate, cinnamic, and ferulic acids related to antioxidant activity and catechin, cinnamic, and ferulic acids related to the induced systemic response. Pseudomonas 42P4 can be used as a bioinoculant in pepper plants to enable better agronomic management, decreasing the use of chemical fertilizer to contribute to sustainable agriculture.

Melatonin production by rhizobacteria native strains: Towards sustainable plant growth promotion strategies

In the current context of climate change and water deficit, the selection of native beneficial microorganisms, such as plant growth-promoting rhizobacteria (PGPR), has become a trend for sustainable agriculture due to their ability to improve plant-bacteria interaction with a minimal adverse effect on the soil microbiota compared to commercial PGPR. Until now, the production of phytohormones like melatonin (MT) by native PGPR and their effect on endogenous MT levels in plants have been poorly studied. MT is a ubiquitous phytohormone that protects plants against biotic and abiotic stress by improving the tolerance of stressed plants. In this work, the production of MT by two native PGPR, Enterobacter 64S1 and Pseudomonas 42P4, was evaluated and both PGPR were applied in Arabidopsis thaliana plants grown under drought conditions to assess the inoculation effects. Parameters such as plant growth, leaf cellular membrane damage, leaf protective compounds, and endogenous MT levels under drought and irrigation conditions were evaluated. The results demonstrated that the native strains Pseudomonas 42P4 and Enterobacter 64S1 produce MT and increase the content of endogenous MT in A. thaliana plants under drought. These native strains improved the tolerance of arabidopsis plants to drought by preventing oxidative and membrane damages and improving plant growth. To the best of our knowledge, this is the first report on MT production by native PGPR and their effects on endogenous MT levels in arabidopsis plants, setting the bases to elucidate the role of native PGPR on water deficit conditions.

Halotolerant native bacteria Enterobacter 64S1 and Pseudomonas 42P4 alleviate saline stress in tomato plants

Salinity is one of the principal abiotic stresses that limit the growth and productivity of crops. The use of halotolerant plant growth-promoting rhizobacteria (PGPR) that increase the growth of salt-stressed crops is an environmentally friendly alternative to promote plant yield under salinity. The aim of this study was to test native PGPR, isolated according to their tolerance to NaCl, and to evaluate their influence on morphological, physiological, and biochemical traits promoted by salt stress in tomato plants. Enterobacter 64S1 and Pseudomonas 42P4 were selected as the most efficient strains in terms of salt tolerance. Both strains were classified as moderately resistant to salinity (NaCl) and maintained their plant growth-promoting activities, such as nitrogen fixation and phosphate solubilization, even in the presence of high levels of salt. The results of a greenhouse experiment demonstrated that PGPR inoculation increased root and shoot dry weight, stem diameter, plant height, and leaf area compared to control noninoculated plants under nonsaline stress conditions, reversing the effects of salinity. Inoculated plants showed increased tolerance to salt conditions by reducing electrolyte leakage (improved membrane stability) and lipid peroxidation and increasing chlorophyll quantum efficiency (Fv/Fm) and the performance index. Also, inoculation increased the accumulation of proline and antioxidant nonenzymatic compounds, such as carotenes and total phenolic compounds. The catalase and peroxidase activities increased with salinity, but the effect was reversed by Enterobacter 64S1. In conclusion, Enterobacter 64S1 and Pseudomonas 42P4 isolated from salt-affected regions have the potential to alleviate the deleterious effects of salt stress in tomato crops.

Native bacteria isolated from roots and rhizosphere of Solanum lycopersicum L. increase tomato seedling growth under a reduced fertilization regime

In semiarid regions is important to use native strains best adapted to these environments to optimize plant-PGPR interaction. We aimed to isolate and characterize PGPR from roots and rhizosphere of a tomato crop, as well as studying the effect of its inoculation on tomato seedlings growth. We selected four strains considering their effectiveness of fixing nitrogen, solubilizing phosphate, producing siderophores and indole acetic acid. They belong to the genera Enterobacter, Pseudomonas, Cellulosimicrobium, and Ochrobactrum. In addition, we also analyzed the ability to solubilize Ca₃(PO₄)₂, FePO₄ and AlPO₄ and the presence of one of the genes encoding the cofactor PQQ in their genome. Enterobacter 64S1 and Pseudomonas 42P4 showed the highest phosphorus solubilizing activity and presence of pqqE gene. Furthermore, in a tomato-based bioassay in speed-bed demonstrated that a sole inoculation at seedling stage with the strains increased dry weight of roots (49-88%) and shoots (39-55%), stem height (8-13%) and diameter (5-8%) and leaf area (22-31%) and were equal or even higher than fertilization treatment. Leaf nitrogen and chlorophyll levels were also increased (50-80% and 26-33%) compared to control. These results suggest that Enterobacter 64S1 and Pseudomonas 42P4 can be used as bio-inoculant in order to realize a nutrient integrated management.

Decomposition of Concealed and Exposed Porcine Remains in the North Carolina Piedmont

We examined the decomposition and subsequent insect colonization of small pig carrion (Sus scrofa (L.)) placed in concealed and open environments during spring, summer, and fall in Raleigh, North Carolina, as a model for juvenile human remains. Remains were concealed in simulated attics in three manners, ranging from minimal to well-concealed. Concealment had a significant effect on the insect community colonizing the remains across all three seasons; the beetles Necrobia rufipes (DeGeer) (Cleridae) and Dermestes maculatus (DeGeer) (Coleoptera: Dermestidae) were the only species indicative of remains located indoors, whereas numerous fly (Diptera: Calliphoridae, Muscidae, Sepsidae, and Piophilidae) and beetle (Coleoptera: Silphidae, Staphylinidae, and Histeridae) species and an ant species (Hymenoptera: Formicidae, Prenolepis sp.) were indicative of remains located outdoors. Season also significantly affected the insect species, particularly the blow flies (Diptera: Calliphoridae) colonizing remains: Lucilia illustris (Meigen) was indicative of the spring, Cochliomyia macellaria (F.) and Chrysomya megacephala (F.) were indicative of the summer, and Calliphora vicina Robineau-Desvoidy and Calliphora vomitoria (L.) were indicative of the fall. In addition, across all seasons, colonization was delayed by 35–768 h, depending on the degree of concealment. These differences among the insect communities across seasons and concealment treatments, and the effects of concealment on colonization indicate that such information is important and should to be considered when analyzing entomological evidence for criminal investigations.

Bacteria isolated from roots and rhizosphere of Vitis vinifera retard water losses, induce abscisic acid accumulation and synthesis of defense-related terpenes in in vitro cultured grapevine

Eleven bacterial strains were isolated at different soil depths from roots and rhizosphere of grapevines from a commercial vineyard. By 16S rRNA gene sequencing 10 different genera and 8 possible at species level were identified. From them, Bacillus licheniformis Rt4M10 and Pseudomonas fluorescens Rt6M10 were selected according to their characteristics as plant growth promoting rhizobacteria (PGPR). Both produced abscisic acid (ABA), indole-3-acetic acid (IAA) and the gibberellins A1 and A3 in chemically-defined medium. They also colonized roots of in vitro grown Vitis vinifera cv. Malbec plants. As result of bacterization ABA levels in 45 days-old in vitro plants were increased 76-fold by B. licheniformis and 40-fold by P. fluorescens as compared to controls. Both bacteria diminished plant water loss rate in correlation with increments of ABA. Twenty and 30 days post bacterization the plants incremented terpenes. The monoterpenes α-pinene, terpinolene, 4-carene, limonene, eucalyptol and lilac aldehyde A, and the sesquiterpenes α-bergamotene, α-farnesene, nerolidol and farnesol were assessed by gas chromatography-electron impact mass spectrometry analysis. α-Pinene and nerolidol were the most abundant (µg per g of tissue in plants bacterized with P. fluorescens). Only α-pinene, eucalyptol and farnesol were identified at low concentration in non-bacterized plants treated with ABA, while no terpenes were detected in controls. The results obtained along with others from literature suggest that B. licheniformis and P. fluorescens act as stress alleviators by inducing ABA synthesis so diminishing water losses. These bacteria also elicit synthesis of compounds of plant defense via an ABA independent mechanism.

It's good to talk! Changes in coronary revascularisation practice in PCI centres without onsite surgical cover and the impact of an angiography video conferencing system

INTRODUCTION

Percutaneous coronary intervention (PCI) activity has increased more than 6 fold in the last 15 years. Increased demand has been met by PCI centres without on-site surgical facilities. To improve communication between cardiologists and surgeons at a remote centre, we have developed a video conferencing system using standard internet links. The effect of this video data link (VDL) on referral pattern and patient selection for revascularisation was assessed prospectively after introduction of a joint cardiology conference (JCC) using the system.

METHODS

Between 1st October 2005 and 31st March 2007, 1346 patients underwent diagnostic coronary angiography (CA). Of these, 114 patients were discussed at a cardiology conference (CC) attended by three consultant cardiologists (pre-VDL). In April 2007, the VDL system was introduced. Between 1st April 2007 and 30th September 2008, 1428 patients underwent diagnostic CA. Of these, 120 patients were discussed at a JCC attended by four consultant cardiologists and two consultant cardiothoracic surgeons (post-VDL). Following case-matching for patient demographics and coronary artery disease (CAD) severity and distribution, we assessed the effect upon management decisions arising from both the pre- and post-VDL JCC meetings.

RESULTS

When comparing decision-making outcomes of post-VDL JCC with pre-VDL CC, significantly fewer patients were recommended for PCI (36.8% vs. 17.2% respectively, p = 0.001) and significantly more patients were recommended for surgery (21.1% vs. 48.4% respectively, p < 0.001). There were no significant differences in waiting times for PCI following JCC discussion; however, waiting times for surgical revascularisation were significantly reduced (140.9 ± 71.8 days vs. 99.4 ± 56.6 days respectively, p = 0.045).

CONCLUSIONS

  The VDL system provides a highly practical method for PCI centres without onsite surgical cover to discuss complex patients requiring coronary revascularisation and significantly increases the number of patients referred for surgical revascularisation rather than PCI.

Chronic gestational exposure to ethanol causes insulin and IGF resistance and impairs acetylcholine homeostasis in the brain

In fetal alcohol syndrome (FAS), cerebellar hypoplasia is associated with impaired insulin-stimulated survival signaling. This study characterizes ethanol dose-effects on cerebellar development, expression of genes required for insulin and insulin-like growth factor (IGF) signaling, and the upstream mechanisms and downstream consequences of impaired signaling in relation to acetylcholine (ACh) homeostasis. Pregnant Long Evans rats were fed isocaloric liquid diets containing 0%, 2%, 4.5%, 6.5%, or 9.25% ethanol from gestation day 6. Ethanol caused dose-dependent increases in severity of cerebellar hypoplasia, neuronal loss, proliferation of astrocytes and microglia, and DNA damage. Ethanol also reduced insulin, IGF-I, and IGF-II receptor binding, insulin and IGF-I receptor tyrosine kinase activities, ATP, membrane cholesterol, and choline acetyltransferase (ChAT) expression. In vitro studies linked membrane cholesterol depletion to impaired insulin receptor binding and insulin-stimulated ChAT. In conclusion, cerebellar hypoplasia in FAS is mediated by insulin/IGF resistance with attendant impairments in energy production and ACh homeostasis.

Influence of antimicrobial agents on the spoilage of a meat-based entomophage diet

The microbial decomposition of a meat-based entomophage diet presented in Parafilm packets was investigated. Considerable bacteria but not fungi were associated with components used to prepare the diet (i.e., hens' eggs, liver, and ground beef). At the initial sampling time, there were no differences among diet treatments in the size of bacterial or fungal populations. Bacterial populations in diets not containing antibacterial agents rapidly increased and reached an asymptote by 24 h (approximately 10(10) colony-forming units per gram). Bacterial populations also increased in diets containing antibacterial agents, but they were significantly smaller than in diets not containing antibacterial agents. The most prevalent bacteria isolated were Carnobacterium piscicola, Carnobacterium divergens, Lactobacillus curvatus, Lactobacillus sakei, Leuconostoc mesenteroides, and Enterococcus spp., regardless of the antibacterial treatment used. The proliferation of fungi was delayed relative to bacteria, but significant differences were observed among the diet treatments. Fungi were most inhibited by sorbic acid and propionic acid in the absence of antibacterial agents. The most common fungi isolated were the yeasts Candida zeylanoides, Torulaspora globosa, and Yarrowia lipolytica. The pH of diets not containing antibacterial agents decreased rapidly and was highly correlated with increases in bacteria but not fungi. The results of this study demonstrate that antimicrobial agents significantly inhibit spoilage microorganisms in a meat-based diet and that alternative management strategies to delay the decomposition of such diets presented in Parafilm packets should target lactic acid spoilage bacteria, particularly Carnobacterium and Lactobacillus species.

Demonstration of amylase from the zoophytophagous anthocorid Orius insidiosus

To better understand facultative phytophagy in the zoophytophagous anthocorid, Orius insidiosus, tests for amylase were conducted and the enzyme was partially purified. Three activity bands were detected with polyacrylamide-starch gel electrophoretic analysis of amylase in O. insidiosus. The major amylase was found to have a mean isoelectric point (pI) of 4.53. The presence of amylase indicates the ability of O. insidiosus to use starch, a nutrient, derived from plants, either by direct ingestion or by ingestion of plant material from the digestive system of their prey. The presence of amylase suggests that these predators are more committed to plant feeding than other species of predators that lack this enzyme.

Partial characterization of alpha-amylase in the salivary glands of Lygus hesperus and L. lineolaris

The alpha-amylases in the salivary glands of Lygus hesperus Knight and L. lineolaris (Palisot de Beauvois) were isolated and purified by ion exchange chromatography, and by isoelectric focusing, respectively. The alpha-amylase from L. hesperus had an isoelectric point (pI) of 6.25, and a pH optimum of 6.5. The specific activity of alpha-amylases in the salivary glands of L. hesperus was 1.2 U/mg/ml. The alpha-amylase from L. lineolaris had a pI of 6.54, and a pH optimum of 6.5. The specific activity of alpha-amylase from L. lineolaris was 1.7 U/mg/ml. The activity of alpha-amylase in both species was significantly inhibited by alpha-amylase inhibitor from wheat and also by EDTA and SDS. Sodium chloride enhanced alpha-amylase activity for both species. The enzyme characteristics and relative activities are discussed in the context of differences phytophagous versus zoophagous habits in these two congeneric species.

Comparison of alpha-amylase and protease activities of a zoophytophagous and two phytozoophagous Heteroptera

To better understand the nature of facultative phytophagy in the zoophytophagous Geocoris punctipes (Say), and facultative zoophagy in phytozoophagous Lygus hesperus (Knight) and Lygus lineolaris (Palisot de Beauvois), we compared the activities of both the starch digesting enzyme alpha-amylase and of general proteases in these species. The alpha-amylases and proteases were demonstrated in L. hesperus, L. lineolaris and G. punctipes. The presence of alpha-amylase in the salivary gland complexes of G. punctipes indicates a disposition of this species toward utilization of nutrients that can be derived only from plants, either directly from ingestion of plant macromolecules or from second-hand ingestion of plant material from the digestive system of their prey. The alpha-amylase activity in G. punctipes was much less than those of phytozoophagous L. hesperus and L. lineolaris. The relative importance of amylolytic activity and proteolytic activity is also discussed.

Crystal structure of botulinum neurotoxin type A and implications for toxicity

Botulinum neurotoxin type A (BoNT/A) is the potent disease agent in botulism, a potential biological weapon and an effective therapeutic drug for involuntary muscle disorders. The crystal structure of the entire 1,285 amino acid di-chain neurotoxin was determined at 3.3 A resolution. The structure reveals that the translocation domain contains a central pair of alpha-helices 105 A long and a approximately 50 residue loop or belt that wraps around the catalytic domain. This belt partially occludes a large channel leading to a buried, negative active site--a feature that calls for radically different inhibitor design strategies from those currently used. The fold of the translocation domain suggests a mechanism of pore formation different from other toxins. Lastly, the toxin appears as a hybrid of varied structural motifs and suggests a modular assembly of functional subunits to yield pathogenesis.

Osseointegrated implants for single tooth replacement in general practice: a 1-year report from a multicentre prospective study

The single tooth implant is a treatment option for the replacement of missing single teeth and in many cases is the treatment of choice. It is, however, an expensive treatment requiring a co-ordinated approach to the surgical and restorative aspects of treatment. In this study, a group of dentists in general and restorative dental practice and with no previous experience in implant surgery underwent an intensive training course in all aspects of implant treatment for single teeth. Using a system of simplified instrumentation with a strict adherence to protocol, the group installed and restored single tooth implants ad modum Brånemark in a wide range of clinical situations. At the one year follow-up period following crown insertion, the success rate of treatment compared favourably with results reported from centres using the specialist team approach to treatment. The results of this study indicate that further consideration should be given to the training of general dentists so that improved delivery of dental health care can be provided at a more economic level.

Alterations of fluid and electrolyte balance in thoroughbred racehorses following strenuous exercise during training

Alterations of acid-base status, and fluid and electrolyte balance subsequent to exercise in Thoroughbred racehorses in North America have not been well-characterized. Des-cribed here are the results of an observational study conducted to characterize changes in fluid and electrolytes following strenuous exercise of 16 Thoroughbreds under routine training conditions. Changes following strenuous exercise were determined for the following variables: serum concentrations of sodium (Na), potassium (K), chloride (Cl) and protein; pH of blood; osmolality of plasma and urine; body weight; and, fractional urinary excretion (FE) of Na, K and Cl. The following changes occurred during exercise: increased concentration of Na in blood; increased FE of Na; decreased concentration of Cl in blood; decreased FE of Cl; increased urinary and plasmal osmolality; weight-loss; decreased pH of blood; and, increased concentration of lactic acid. The concurrent decreased concentration of chloride in plasma and acidemia in these horses differed from the hypochloremic, metabolic alkalosis previously described among endurance horses. Acidemia was attributed to production of lactic acid by anaerobic glycolysis.

Residual, unresectable, or recurrent colorectal cancer: external beam irradiation and intraoperative electron beam boost +/- resection

While combinations of external beam radiation (XRT) and surgery decrease pelvic recurrence and improve survival in the subgroups with residual disease (postop XRT) or initially unresectable disease (preop XRT), local recurrence is still unacceptably high, and survival could be improved. In view of this, pilot studies were instituted at Massachusetts General Hospital in which 32 patients received the standard previous treatment of external beam irradiation and surgery but in addition had an intraoperative electron beam boost of 1000-1500 rad to the remaining tumor or tumor bed. For the 16 patients who presented with unresectable primary lesions, the addition of intraoperative radiotherapy has resulted in a total absence of local recurrence with a minimum 20 month follow-up, and survival rates are statistically better than for the previous group treated with only external beam irradiation and surgical resection. In the group with residual disease, again there have not been any local recurrences in the 7 patients who received all treatment modalities versus 54% and 26% for the group with gross and microscopic residual treated with only external beam techniques. The remaining 9 patients presented with recurrent unresectable lesions--3 are alive (2 NED) at greater than or equal to 3 years.

Low-dose preoperative irradiation, surgery, and elective postoperative radiation therapy for resectable rectum and rectosigmoid carcinoma

A regimen of low-dose preoperative radiation therapy (RT), surgery, and elective postoperative RT for resectable carcinomas of the rectum and rectosigmoid is presented. Initial results in a group of 36 patients is discussed. In four patients clinically silent metastatic disease was discovered. Of 16 patients without indications for postoperative RT, only one died with disease. Indications for postoperative irradiation were found in 15 patients and four relapses (26%) subsequently occurred. Since the surgicopathologic stage of the tumor is the best prognostic predictor for rectal cancer, this regimen allows for the delivery of high-dose adjuvant irradiation only to those at high risk of local recurrence. Thus, this combination selects patients likely to benefit from postoperative RT while preserving the advantages of preoperative RT.

Combined modality treatment of gastric cancer

In a series of 46 patients with localized gastric cancer treated at Massachusetts General Hospital, problems with excessive acute or chronic toxicity due to combination treatment with irradiation (XRT) and chemotherapy (CT) were not seen. Forty of the 46 received combined treatment with 2 regimens: 1) Irradiation plus concomitant 3 days of 5-FU followed by maintenance 5-FU or combined drugs--26 patients; 2) In the other 14 patients, the sequence of irradiation and chemotherapy was altered. A single course of combined drug chemotherapy was given prior to irradiation and 5-6 additional courses were administered after completion of XRT (CT-XRT-CT). The drug combination was initially 5-FU-BCNU but this was changed to FAM (5-FU, Adriamycin, Mitomycin C). Irradiation was delivered to tightly contoured portals using shaped blocks to spare as much small bowel, kidney and marrow as possible while giving 4500-5200 rad in 25 to 29 fractions over 5 to 6 weeks. In this series, there were no cases of septicemia or any deaths related to treatment. A 3 year survival rate of about 20% was achieved for the total group of patients and 43% in the group with resection but at high risk for later failure. Our inability to improve these numbers is undoubtedly a result of dose limitations with external beam irradiation combined with a systemic failure problem. When irradiation is combined with surgical resection of all or a majority of tumor, both survival and local control appear to be better than in the unresected patient group. Only 4 of 29 patients (14%) with curative resection, or resection but residual disease, had later evidence of failure within the irradiation field as opposed to 6 of 9 or 66% in the group with unresectable disease.