WorldWideScience

Sample records for bacterial biological control

  1. Biological Control of Bacterial Wilt in South East Asia

    OpenAIRE

    Arwiyanto, Triwidodo

    2014-01-01

    Bacterial wilt disease caused by Ralstonia solanacearum destroys many crops of different plant families in South East Asia despite many researches about the disease, and the availability of developed control method in other parts of the world. There is no chemical available for the bacterial wilt pathogen and biological control is then chosen as an alternative to save the crops. Most of the biological control studies were based on antagonism between biological control agent and the pathogen. ...

  2. Studies on bacterial flora and biological control agent of Cydia ...

    African Journals Online (AJOL)

    In the present study, in order to find a more effective and safe biological control agent against Cydia pomonella, we investigated the bacterial flora and tested them for insecticidal effects on this insect. According to morphological, physiological and biochemical tests, bacterial flora were identified as Proteus rettgeri (Cp1), ...

  3. Biological Control of Bacterial Wilt in South East Asia

    Directory of Open Access Journals (Sweden)

    Triwidodo Arwiyanto

    2014-12-01

    Full Text Available Bacterial wilt disease caused by Ralstonia solanacearum destroys many crops of different plant families in South East Asia despite many researches about the disease, and the availability of developed control method in other parts of the world. There is no chemical available for the bacterial wilt pathogen and biological control is then chosen as an alternative to save the crops. Most of the biological control studies were based on antagonism between biological control agent and the pathogen. The biological control agents were intended to reduce the initial inoculum of the pathogen. The effort to minimize the initial inoculum of the pathogen by baiting with the use of hypersensitive host-plant was only reliable when conducted in the greenhouse experiments. Various microorganisms have been searched as possible biological control agents, for instance avirulent form of the pathogen, soil or rhizosphere bacteria (Bacillus spp. and fluorescent pseudomonads, actinomycetes (Streptomyces spp., yeast (Pichia uillermondii, Candida ethanolica, and a consortium of microorganisms known as effective microorganisms (EM. None of these biological control agents has been used in field application and they need further investigation in order to effectively control bacterial wilt. Opportunities and challenges in developing biological control to combat bacterial wilt are discussed in the paper. Penyakit layu bakteri yang disebabkan oleh Ralstonia solanacearum menghancurkan banyak tanaman dalam famili yang berbeda di Asia Tenggara meskipun telah banyak penelitian tentang metode pengendaliannya. Penyakit ini sulit dikendalikan karena banyaknya variabilitas patogen dan belum tersedianya sumber ketahanan yang mapan. Di samping itu, sampai saat ini belum ada bahan kimia yang tersedia untuk patogen layu bakteri ini sehingga pengendalian biologi kemudian dipilih sebagai cara alternatif untuk menyelamatkan tanaman. Sebagian besar penelitian pengendalian biologi didasarkan

  4. Screening of bacterial antagonists for biological control of Phytophthora blight of pepper.

    Science.gov (United States)

    Rajkumar, M; Lee, Wang Hyu; Lee, Kui Jae

    2005-01-01

    The aim of this study was to assess the potential of bacterial antagonists to control Phytophthora blight of pepper caused by P. capsici using different screening methods. Among a collection of fluorescent pseudomonas isolated from the rhizosphere of pepper, twelve isolates were initially selected based on dual culture assay on potato dextrose agar and corn meal agar. Further, these twelve isolates were screened for the reduction of disease severity caused by P. capsici using detached leaves and seedling assay. Most of the antagonists showed varying levels of antagonism against P. capsici in both detached leaves and seedlings assay. In addition, few isolates increased shoot and root length of pepper in seedling assays. Among them, isolate PS119 showing highest ability to reduce the disease severity in the in vitro seedling assay was found to be the most efficient antagonists against P. capsici in the in vivo biological control tests. These results indicate that the in vitro seedling assay can be used as a rapid and more accurate technique for the selection of promising biocontrol agents against P. capsici. ((c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

  5. Biological control of bacterial spot of tomato by saprobe fungi from semi-arid areas of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Douglas Casaroto Peitl

    2017-06-01

    Full Text Available Bacterial spot of tomato, caused by Xanthomonas spp., is a common disease in tomato fields that causes significant economic losses. Due to the difficulty with control of bacterial spot by conventional methods, new techniques such as biological control and induction of resistance are gaining prominence. This study aimed to select saprobe fungi from semi-arid regions of the Brazilian Northeast for the biological control of bacterial spot of tomato. To select the best isolates to control bacterial spot, a greenhouse experiment was initially conducted. Tomato plants (‘Santa Cruz Kada’ were treated with filtrates of 25 saprobe fungi and inoculated three days later with Xanthomonas euvesicatoria. Filtrates of Memnoniella levispora, Periconia hispidula, Zygosporium echinosporum, and Chloridium virescens var. virescens were selected as the most effective. Filtrates and volatile compounds from these four isolates were tested for their antibacterial activity in cultures of X. euvesicatoria and in tomato plants (‘Santa Cruz Kada’ inoculated with X. euvesicatoria. In vitro, the addition of nonvolatile fungal metabolites into the culture medium at 5% and 50% (v/v inhibited bacterial growth by 28.9% and 53.8%, respectively. The volatile compounds produced by C. virescens var. virescens reduced the number of colony-forming units of X. euvesicatoria by 25.9%. In vivo, all treatments reduced from 62.4 to 71.3% the area under bacterial spot progress curve, showing the same control efficacy as the commercial resistance inducer used as a positive control (acibenzolar-S-methyl. Systemicity of the fungal filtrates was confirmed in a separate experiment, where application of the treatments exclusively to the third leaf decreased the severity of the disease on the fourth leaf (except for C. virescens var. virescens. These results show that M. levispora, P. hispidula, Z. echinosporum, and C. virescens var. virescens are potential biocontrol agents against

  6. Bacterial control of cyanobacteria

    CSIR Research Space (South Africa)

    Ndlela, Luyanda L

    2017-08-01

    Full Text Available of biological control appears to be direct contact. • Ndlela, L. L. et al. (2016) ‘An overview of cyanobacterial bloom occurrences and research in Africa over the last decade’, Harmful Algae, 60 • Gumbo, J.R. et al. (2010) The Isolation and identification... of Predatory Bacteria from a Microcystis algal Bloom.. African Journal of Biotechnology, 9. *Special acknowledgement goes to the National Research foundation for funding this presentation Bacterial control of cyanobacteria Luyanda...

  7. Bacterial selection for biological control of plant disease: criterion determination and validation

    Directory of Open Access Journals (Sweden)

    Monalize Salete Mota

    Full Text Available Abstract This study aimed to evaluate the biocontrol potential of bacteria isolated from different plant species and soils. The production of compounds related to phytopathogen biocontrol and/or promotion of plant growth in bacterial isolates was evaluated by measuring the production of antimicrobial compounds (ammonia and antibiosis and hydrolytic enzymes (amylases, lipases, proteases, and chitinases and phosphate solubilization. Of the 1219 bacterial isolates, 92% produced one or more of the eight compounds evaluated, but only 1% of the isolates produced all the compounds. Proteolytic activity was most frequently observed among the bacterial isolates. Among the compounds which often determine the success of biocontrol, 43% produced compounds which inhibit mycelial growth of Monilinia fructicola, but only 11% hydrolyzed chitin. Bacteria from different plant species (rhizosphere or phylloplane exhibited differences in the ability to produce the compounds evaluated. Most bacterial isolates with biocontrol potential were isolated from rhizospheric soil. The most efficient bacteria (producing at least five compounds related to phytopathogen biocontrol and/or plant growth, 86 in total, were evaluated for their biocontrol potential by observing their ability to kill juvenile Mesocriconema xenoplax. Thus, we clearly observed that bacteria that produced more compounds related to phytopathogen biocontrol and/or plant growth had a higher efficacy for nematode biocontrol, which validated the selection strategy used.

  8. Biological Control of Bacterial Fruit Blotch of Watermelon Pathogen (Acidovorax citrulli with Rhizosphere Associated Bacteria

    Directory of Open Access Journals (Sweden)

    Mahesh Adhikari

    2017-04-01

    Full Text Available Bacterial fruit blotch (BFB, which is caused by Acidovorax citrulli, is a serious threat to watermelon growers around the world. The present study was conducted to screen effective rhizobacterial isolates against 35 different A. citrulli isolates and determine their efficacy on BFB and growth parameters of watermelon. Two rhizobacterial isolates viz. Paenibacillus polymyxa (SN-22, Sinomonas atrocyanea (NSB-27 showed high inhibitory activity in the preliminary screening and were further evaluated for their effect on BFB and growth parameters of three different watermelon varieties under greenhouse conditions. The greenhouse experiment result revealed that SN-22 and NSB-27 significantly reduced BFB and had significant stimulatory effect on total chlorophyll content, plant height, total fresh weight and total dry weight compared to uninoculated plants across the tested three watermelon varieties. Analysis of the 16S ribosomal RNA (rRNA sequences revealed that strains SN-22 belong to P. polymyxa and NSB-27 to S. atrocyanea with the bootstrap value of 99% and 98%, respectively. The isolates SN-22 and NSB-27 were tested for antagonistic and PGP traits. The result showed that the tested isolates produced siderophore, hydrolytic enzymes (protease and cellulose, chitinase, starch hydrolytic enzymes and they showed phosphate as well as zinc solubilizing capacity. This is the first report of P. polymyxa (SN-22 and S. atrocyanea (NSB-27 as biocontrol-plant growth promoting rhizobacteria on watermelon.

  9. Restoring vaginal microbiota: biological control of bacterial vaginosis. A prospective case-control study using Lactobacillus rhamnosus BMX 54 as adjuvant treatment against bacterial vaginosis.

    Science.gov (United States)

    Recine, Nadia; Palma, Ettore; Domenici, Lavinia; Giorgini, Margherita; Imperiale, Ludovica; Sassu, Carolina; Musella, Angela; Marchetti, Claudia; Muzii, Ludovico; Benedetti Panici, Pierluigi

    2016-01-01

    Bacterial vaginosis (BV) is the most prevalent lower genital tract infection in reproductive-age women worldwide. BV is an ecological disorder of the vaginal microbiota characterized microbiologically by replacement of the lactobacilli, predominant vaginal microbiota. It is characterized by a high rate of relapse in sexual active women, and these patients show three or more relapses each year. A healthy vagina is characterized by hydrogen peroxide and acid-producing lactobacilli, which are crucial to maintain the physiological vaginal ecosystem and their depletion speeds up bacterial overgrowth with pH elevation, salidase and amine production, leading to the observed signs and symptoms of BV. The aim of this study is to evaluate the efficacy of long-term vaginal lactobacilli's implementation in restoring and maintaining vaginal microflora and pH and to collect data about prophylactic approach based on probiotics supplementation with lactobacilli. This is a prospective case-control study, performed between January 2013 and September 2014 at Department of Gynecological Obstetrics and Urologic Sciences of "Sapienza" University of Rome. 250 non-pregnant sexually active women with diagnoses of BV were collected. Patients selected were divided in Group A (125 patients assigned to standard treatment for BV-metronidazole 500 mg orally twice a day for 7 days) and Group B (125 women undergoing the same standard antibiotic regimen followed by vaginal tablets containing Lactobacillus rhamnosus BMX 54). Patients were evaluated after 2, 6, and 9 months (T0, T2, T6, and T9) in term of recurrences rates of BV, vaginal symptoms, re-establishment of healthy vaginal flora, vaginal pH, and treatment tolerability. Vaginal flora was significantly replaced in Group B patients after 2 months comparing with Group A (p = 0.014). These data were confirmed at 6 and 9 months follow-up: patients that underwent prophylactic therapy with NORMOGIN(®) experienced significantly low rate of

  10. A systematic approach for the assessment of bacterial growth-controlling factors linked to biological stability of drinking water in distribution systems

    KAUST Repository

    Prest, E. I.

    2016-01-06

    A systematic approach is presented for the assessment of (i) bacterial growth-controlling factors in drinking water and (ii) the impact of distribution conditions on the extent of bacterial growth in full-scale distribution systems. The approach combines (i) quantification of changes in autochthonous bacterial cell concentrations in full-scale distribution systems with (ii) laboratoryscale batch bacterial growth potential tests of drinking water samples under defined conditions. The growth potential tests were done by direct incubation of water samples, without modification of the original bacterial flora, and with flow cytometric quantification of bacterial growth. This method was shown to be reproducible (ca. 4% relative standard deviation) and sensitive (detection of bacterial growth down to 5 μg L-1 of added assimilable organic carbon). The principle of step-wise assessment of bacterial growth-controlling factors was demonstrated on bottled water, shown to be primarily carbon limited at 133 (±18) × 103 cells mL-1 and secondarily limited by inorganic nutrients at 5,500 (±1,700) × 103 cells mL-1. Analysis of the effluent of a Dutch full-scale drinking water treatment plant showed (1) bacterial growth inhibition as a result of end-point chlorination, (2) organic carbon limitation at 192 (±72) × 103 cells mL-1 and (3) inorganic nutrient limitation at 375 (±31) × 103 cells mL-1. Significantly lower net bacterial growth was measured in the corresponding full-scale distribution system (176 (±25) × 103 cells mL-1) than in the laboratory-scale growth potential test of the same water (294 (±35) × 103 cells mL-1), highlighting the influence of distribution on bacterial growth. The systematic approach described herein provides quantitative information on the effect of drinking water properties and distribution system conditions on biological stability, which can assist water utilities in decision-making on treatment or distribution system improvements to

  11. A systematic approach for the assessment of bacterial growth-controlling factors linked to biological stability of drinking water in distribution systems

    KAUST Repository

    Prest, E. I.; Hammes, F.; Kotzsch, S.; van Loosdrecht, M. C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    A systematic approach is presented for the assessment of (i) bacterial growth-controlling factors in drinking water and (ii) the impact of distribution conditions on the extent of bacterial growth in full-scale distribution systems. The approach

  12. Effect of Producing Different Phenazines on Bacterial Fitness and Biological Control in Pseudomonas chlororaphis 30-84

    Directory of Open Access Journals (Sweden)

    Jun Myoung Yu

    2018-02-01

    Full Text Available Pseudomonas chlororaphis 30-84 is a biological control agent selected for its ability to suppress diseases caused by fungal pathogens. P. chlororaphis 30-84 produces three phenazines: phenazine-1-carboxylic acid (PCA, 2-hydroxy-phenazine-1-carboxylic acid (2OHPCA and a small amount of 2-hydroxy-phenazine (2OHPHZ, and these are required for fungal pathogen inhibition and wheat rhizosphere competence. The two, 2-hydroxy derivatives are produced from PCA via the activity of a phenazine-modifying enzyme encoded by phzO. In addition to the seven biosynthetic genes responsible for the production of PCA, many other Pseudomonas strains possess one or more modifying genes, which encode enzymes that act independently or together to convert PCA into other phenazine derivatives. In order to understand the fitness effects of producing different phenazines, we constructed isogenic derivatives of P. chlororaphis 30-84 that differed only in the type of phenazines produced. Altering the type of phenazines produced by P. chlororaphis 30-84 enhanced the spectrum of fungal pathogens inhibited and altered the degree of take-all disease suppression. These strains also differed in their ability to promote extracellular DNA release, which may contribute to the observed differences in the amount of biofilm produced. All derivatives were equally important for survival over repeated plant/harvest cycles, indicating that the type of phenazines produced is less important for persistence in the wheat rhizosphere than whether or not cells produce phenazines. These findings provide a better understanding of the effects of different phenazines on functions important for biological control activity with implications for applications that rely on introduced or native phenazine producing populations.

  13. Identification of an Endophytic Antifungal Bacterial Strain Isolated from the Rubber Tree and Its Application in the Biological Control of Banana Fusarium Wilt.

    Directory of Open Access Journals (Sweden)

    Deguan Tan

    Full Text Available Banana Fusarium wilt (also known as Panama disease is one of the most disastrous plant diseases. Effective control methods are still under exploring. The endophytic bacterial strain ITBB B5-1 was isolated from the rubber tree, and identified as Serratia marcescens by morphological, biochemical, and phylogenetic analyses. This strain exhibited a high potential for biological control against the banana Fusarium disease. Visual agar plate assay showed that ITBB B5-1 restricted the mycelial growth of the pathogenic fungus Fusarium oxysporum f. sp. cubense race 4 (FOC4. Microscopic observation revealed that the cell wall of the FOC4 mycelium close to the co-cultured bacterium was partially decomposed, and the conidial formation was prohibited. The inhibition ratio of the culture fluid of ITBB B5-1 against the pathogenic fungus was 95.4% as estimated by tip culture assay. Chitinase and glucanase activity was detected in the culture fluid, and the highest activity was obtained at Day 2 and Day 3 of incubation for chitinase and glucanase, respectively. The filtrated cell-free culture fluid degraded the cell wall of FOC4 mycelium. These results indicated that chitinase and glucanase were involved in the antifungal mechanism of ITBB B5-1. The potted banana plants that were inoculated with ITBB B5-1 before infection with FOC4 showed 78.7% reduction in the disease severity index in the green house experiments. In the field trials, ITBB B5-1 showed a control effect of approximately 70.0% against the disease. Therefore, the endophytic bacterial strain ITBB B5-1 could be applied in the biological control of banana Fusarium wilt.

  14. CRISPR-mediated control of the bacterial initiation of replication

    NARCIS (Netherlands)

    Wiktor, J.M.; Lesterlin, Christian; Sherratt, David J.; Dekker, C.

    2016-01-01

    Programmable control of the cell cycle has been shown to be a powerful tool in cell-biology studies. Here, we develop a novel system for controlling the bacterial cell cycle, based on binding of CRISPR/dCas9 to the origin-of-replication locus. Initiation of replication of bacterial chromosomes is

  15. Utilization of chitinolytic bacterial isolates to control anthracnose of ...

    African Journals Online (AJOL)

    Colletotrichum spp. are causal agents of anthracnose in many plant species. Biological control of Colletotrichum spp. utilizing bacterial isolates and fungi has been reported. However, chitinolytic bacterial isolate utilization to control anthracnose of cocoa leaf has not seemingly been studied yet. In this study, we used ...

  16. Integrated Biological Control

    International Nuclear Information System (INIS)

    JOHNSON, A.R.

    2002-01-01

    Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects; and microorganisms such as molds that adversely affect the quality of the workplace environment). Biological control activities may be either preventive (apriori) or in response to existing contamination spread (aposteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and apriori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, aposteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response

  17. Exotic biological control agents

    NARCIS (Netherlands)

    Hajek, Ann E.; Hurley, Brett P.; Kenis, Marc; Garnas, Jeffrey R.; Bush, Samantha J.; Wingfield, Michael J.; Lenteren, van Joop C.; Cock, Matthew J.W.

    2016-01-01

    Biological control is a valuable and effective strategy for controlling arthropod pests and has been used extensively against invasive arthropods. As one approach for control of invasives, exotic natural enemies from the native range of a pest are introduced to areas where control is needed.

  18. Bacterial Ice Crystal Controlling Proteins

    Science.gov (United States)

    Lorv, Janet S. H.; Rose, David R.; Glick, Bernard R.

    2014-01-01

    Across the world, many ice active bacteria utilize ice crystal controlling proteins for aid in freezing tolerance at subzero temperatures. Ice crystal controlling proteins include both antifreeze and ice nucleation proteins. Antifreeze proteins minimize freezing damage by inhibiting growth of large ice crystals, while ice nucleation proteins induce formation of embryonic ice crystals. Although both protein classes have differing functions, these proteins use the same ice binding mechanisms. Rather than direct binding, it is probable that these protein classes create an ice surface prior to ice crystal surface adsorption. Function is differentiated by molecular size of the protein. This paper reviews the similar and different aspects of bacterial antifreeze and ice nucleation proteins, the role of these proteins in freezing tolerance, prevalence of these proteins in psychrophiles, and current mechanisms of protein-ice interactions. PMID:24579057

  19. Insecticides and Biological Control

    Science.gov (United States)

    Furness, G. O.

    1972-01-01

    Use of insecticides has been questioned due to their harmful effects on edible items. Biological control of insects along with other effective practices for checking spread of parasites on crops are discussed. (PS)

  20. Discovery of novel bacterial toxins by genomics and computational biology.

    Science.gov (United States)

    Doxey, Andrew C; Mansfield, Michael J; Montecucco, Cesare

    2018-06-01

    Hundreds and hundreds of bacterial protein toxins are presently known. Traditionally, toxin identification begins with pathological studies of bacterial infectious disease. Following identification and cultivation of a bacterial pathogen, the protein toxin is purified from the culture medium and its pathogenic activity is studied using the methods of biochemistry and structural biology, cell biology, tissue and organ biology, and appropriate animal models, supplemented by bioimaging techniques. The ongoing and explosive development of high-throughput DNA sequencing and bioinformatic approaches have set in motion a revolution in many fields of biology, including microbiology. One consequence is that genes encoding novel bacterial toxins can be identified by bioinformatic and computational methods based on previous knowledge accumulated from studies of the biology and pathology of thousands of known bacterial protein toxins. Starting from the paradigmatic cases of diphtheria toxin, tetanus and botulinum neurotoxins, this review discusses traditional experimental approaches as well as bioinformatics and genomics-driven approaches that facilitate the discovery of novel bacterial toxins. We discuss recent work on the identification of novel botulinum-like toxins from genera such as Weissella, Chryseobacterium, and Enteroccocus, and the implications of these computationally identified toxins in the field. Finally, we discuss the promise of metagenomics in the discovery of novel toxins and their ecological niches, and present data suggesting the existence of uncharacterized, botulinum-like toxin genes in insect gut metagenomes. Copyright © 2018. Published by Elsevier Ltd.

  1. Bacterial genome engineering and synthetic biology: combating pathogens.

    Science.gov (United States)

    Krishnamurthy, Malathy; Moore, Richard T; Rajamani, Sathish; Panchal, Rekha G

    2016-11-04

    The emergence and prevalence of multidrug resistant (MDR) pathogenic bacteria poses a serious threat to human and animal health globally. Nosocomial infections and common ailments such as pneumonia, wound, urinary tract, and bloodstream infections are becoming more challenging to treat due to the rapid spread of MDR pathogenic bacteria. According to recent reports by the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC), there is an unprecedented increase in the occurrence of MDR infections worldwide. The rise in these infections has generated an economic strain worldwide, prompting the WHO to endorse a global action plan to improve awareness and understanding of antimicrobial resistance. This health crisis necessitates an immediate action to target the underlying mechanisms of drug resistance in bacteria. The advent of new bacterial genome engineering and synthetic biology (SB) tools is providing promising diagnostic and treatment plans to monitor and treat widespread recalcitrant bacterial infections. Key advances in genetic engineering approaches can successfully aid in targeting and editing pathogenic bacterial genomes for understanding and mitigating drug resistance mechanisms. In this review, we discuss the application of specific genome engineering and SB methods such as recombineering, clustered regularly interspaced short palindromic repeats (CRISPR), and bacterial cell-cell signaling mechanisms for pathogen targeting. The utility of these tools in developing antibacterial strategies such as novel antibiotic production, phage therapy, diagnostics and vaccine production to name a few, are also highlighted. The prevalent use of antibiotics and the spread of MDR bacteria raise the prospect of a post-antibiotic era, which underscores the need for developing novel therapeutics to target MDR pathogens. The development of enabling SB technologies offers promising solutions to deliver safe and effective antibacterial therapies.

  2. Review of Pasteuria penetrans: Biology, Ecology, and Biological Control Potential.

    Science.gov (United States)

    Chen, Z X; Dickson, D W

    1998-09-01

    Pasteuria penetrans is a mycelial, endospore-forming, bacterial parasite that has shown great potential as a biological control agent of root-knot nematodes. Considerable progress has been made during the last 10 years in understanding its biology and importance as an agent capable of effectively suppressing root-knot nematodes in field soil. The objective of this review is to summarize the current knowledge of the biology, ecology, and biological control potential of P. penetrans and other Pasteuria members. Pasteuria spp. are distributed worldwide and have been reported from 323 nematode species belonging to 116 genera of free-living, predatory, plant-parasitic, and entomopathogenic nematodes. Artificial cultivation of P. penetrans has met with limited success; large-scale production of endospores depends on in vivo cultivation. Temperature affects endospore attachment, germination, pathogenesis, and completion of the life cycle in the nematode pseudocoelom. The biological control potential of Pasteuria spp. have been demonstrated on 20 crops; host nematodes include Belonolaimus longicaudatus, Heterodera spp., Meloidogyne spp., and Xiphinema diversicaudatum. Pasteuria penetrans plays an important role in some suppressive soils. The efficacy of the bacterium as a biological control agent has been examined. Approximately 100,000 endospores/g of soil provided immediate control of the peanut root-knot nematode, whereas 1,000 and 5,000 endospores/g of soil each amplified in the host nematode and became suppressive after 3 years.

  3. Biological control of ticks

    Science.gov (United States)

    Samish, M.; Ginsberg, H.; Glazer, I.; Bowman, A.S.; Nuttall, P.

    2004-01-01

    Ticks have numerous natural enemies, but only a few species have been evaluated as tick biocontrol agents (BCAs). Some laboratory results suggest that several bacteria are pathogenic to ticks, but their mode of action and their potential value as biocontrol agents remain to be determined. The most promising entomopathogenic fungi appear to be Metarhizium anisopliae and Beauveria bassiana, strains of which are already commercially available for the control of some pests. Development of effective formulations is critical for tick management. Entomopathogenic nematodes that are pathogenic to ticks can potentially control ticks, but improved formulations and selection of novel nematode strains are needed. Parasitoid wasps of the genus Ixodiphagus do not typically control ticks under natural conditions, but inundative releases show potential value. Most predators of ticks are generalists, with a limited potential for tick management (one possible exception is oxpeckers in Africa). Biological control is likely to play a substantial role in future IPM programmes for ticks because of the diversity of taxa that show high potential as tick BCAs. Considerable research is required to select appropriate strains, develop them as BCAs, establish their effectiveness, and devise production strategies to bring them to practical use.

  4. Biological Control of Plant Disease Caused by Bacteria

    Directory of Open Access Journals (Sweden)

    Triwidodo Arwiyanto

    2014-07-01

    Full Text Available Bacterial diseases in plants are difficult to control. The emphasis is on preventing the spread of the bacteria rather than curing the diseased plant. Integrated management measures for bacterial plant pathogens should be applied for successfull control. Biological control is one of the control measures viz. through the use of microorganisms to suppress the growth and development of bacterial plant pathogen and ultimately reduce the possibility of disease onset. The study of biological control of bacterial plant pathogen was just began compared with of fungal plant pathogen. The ecological nature of diverse bacterial plant pathogens has led scientists to apply different approach in the investigation of its biological control. The complex process of entrance to its host plant for certain soil-borne bacterial plant pathogens need special techniques and combination of more than one biological control agent. Problem and progress in controlling bacterial plant pathogens biologically will be discussed in more detail in the paper and some commercial products of biological control agents (biopesticides will be introduced.     Penyakit tumbuhan karena bakteri sulit dikendalikan. Penekanan pengendalian adalah pada pencegahan penyebaran bakteri patogen dan bukan pada penyembuhan tanaman yang sudah sakit. Untuk suksesnya pengendalian bakteri patogen tumbuhan diperlukan cara pengelolaan yang terpadu. Pengendalian secara biologi merupakan salah satu cara pengendalian dengan menggunakan mikroorganisme untuk menekan pertumbuhan dan perkembangan bakteri patogen tumbuhan dengan tujuan akhir menurunkan kemungkinan timbulnya penyakit. Sifat ekologi bakteri patogen tumbuhan yang berbeda-beda mengharuskan pendekatan yang berbeda pula dalam pengendaliannya secara biologi. Masalah dan perkembangan dalam pengendalian bakteri patogen tumbuhan secara biologi didiskusikan secara detail dalam makalah ini.

  5. Biological treatment of aqueous effluents in a bacterial bed

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-14

    Biological treatment of aqueous effluents in a bacterial bed is carried out effectively for refinery waters having a low five-day BOD by using a plastic packing to support the bacteria in place of the less reliable pozzolana (volcanic ash) formerly employed. Such biofilters, developed by Lurgi S.A., are more sensitive to BOD overloading than activated sludge beds, so that very stable operating conditions are required. In these bacterial beds, the water trickles over the plastic packing and becomes oxygenated, which leads to degradation of undesirable substances in the water. In the refinery, this process can give excellent results when properly carried out, but the biofilter may generate suspended matter under unsatisfactory operating conditions, and is therefore usually placed upstream from the flocculation and filtration units. To date, all installations have remained below the required standard limit of 30 mg/l. of suspended matter.

  6. Biological control of toxic cyanobacteria

    CSIR Research Space (South Africa)

    Ndlela, L

    2016-04-01

    Full Text Available harmful algal blooms and their impacts in over 30 countries. Biological control is a method of introducing natural enemies to control an organism and has been more successful using microorganisms....

  7. CRISPR-mediated control of the bacterial initiation of replication.

    Science.gov (United States)

    Wiktor, Jakub; Lesterlin, Christian; Sherratt, David J; Dekker, Cees

    2016-05-05

    Programmable control of the cell cycle has been shown to be a powerful tool in cell-biology studies. Here, we develop a novel system for controlling the bacterial cell cycle, based on binding of CRISPR/dCas9 to the origin-of-replication locus. Initiation of replication of bacterial chromosomes is accurately regulated by the DnaA protein, which promotes the unwinding of DNA at oriC We demonstrate that the binding of CRISPR/dCas9 to any position within origin or replication blocks the initiation of replication. Serial-dilution plating, single-cell fluorescence microscopy, and flow-cytometry experiments show that ongoing rounds of chromosome replication are finished upon CRISPR/dCas9 binding, but no new rounds are initiated. Upon arrest, cells stay metabolically active and accumulate cell mass. We find that elevating the temperature from 37 to 42°C releases the CRISR/dCas9 replication inhibition, and we use this feature to recover cells from the arrest. Our simple and robust method of controlling the bacterial cell cycle is a useful asset for synthetic biology and DNA-replication studies in particular. The inactivation of CRISPR/dCas9 binding at elevated temperatures may furthermore be of wide interest for CRISPR/Cas9 applications in genomic engineering. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Bacterial microcompartments as metabolic modules for plant synthetic biology.

    Science.gov (United States)

    Gonzalez-Esquer, C Raul; Newnham, Sarah E; Kerfeld, Cheryl A

    2016-07-01

    Bacterial microcompartments (BMCs) are megadalton-sized protein assemblies that enclose segments of metabolic pathways within cells. They increase the catalytic efficiency of the encapsulated enzymes while sequestering volatile or toxic intermediates from the bulk cytosol. The first BMCs discovered were the carboxysomes of cyanobacteria. Carboxysomes compartmentalize the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) with carbonic anhydrase. They enhance the carboxylase activity of RuBisCO by increasing the local concentration of CO2 in the vicinity of the enzyme's active site. As a metabolic module for carbon fixation, carboxysomes could be transferred to eukaryotic organisms (e.g. plants) to increase photosynthetic efficiency. Within the scope of synthetic biology, carboxysomes and other BMCs hold even greater potential when considered a source of building blocks for the development of nanoreactors or three-dimensional scaffolds to increase the efficiency of either native or heterologously expressed enzymes. The carboxysome serves as an ideal model system for testing approaches to engineering BMCs because their expression in cyanobacteria provides a sensitive screen for form (appearance of polyhedral bodies) and function (ability to grow on air). We recount recent progress in the re-engineering of the carboxysome shell and core to offer a conceptual framework for the development of BMC-based architectures for applications in plant synthetic biology. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  9. Bacterial lipoproteins; biogenesis, sorting and quality control.

    Science.gov (United States)

    Narita, Shin-Ichiro; Tokuda, Hajime

    2017-11-01

    Bacterial lipoproteins are a subset of membrane proteins localized on either leaflet of the lipid bilayer. These proteins are anchored to membranes through their N-terminal lipid moiety attached to a conserved Cys. Since the protein moiety of most lipoproteins is hydrophilic, they are expected to play various roles in a hydrophilic environment outside the cytoplasmic membrane. Gram-negative bacteria such as Escherichia coli possess an outer membrane, to which most lipoproteins are sorted. The Lol pathway plays a central role in the sorting of lipoproteins to the outer membrane after lipoprotein precursors are processed to mature forms in the cytoplasmic membrane. Most lipoproteins are anchored to the inner leaflet of the outer membrane with their protein moiety in the periplasm. However, recent studies indicated that some lipoproteins further undergo topology change in the outer membrane, and play critical roles in the biogenesis and quality control of the outer membrane. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Bacterial Biofilm Control by Perturbation of Bacterial Signaling Processes

    Directory of Open Access Journals (Sweden)

    Tim Holm Jakobsen

    2017-09-01

    Full Text Available The development of effective strategies to combat biofilm infections by means of either mechanical or chemical approaches could dramatically change today’s treatment procedures for the benefit of thousands of patients. Remarkably, considering the increased focus on biofilms in general, there has still not been invented and/or developed any simple, efficient and reliable methods with which to “chemically” eradicate biofilm infections. This underlines the resilience of infective agents present as biofilms and it further emphasizes the insufficiency of today’s approaches used to combat chronic infections. A potential method for biofilm dismantling is chemical interception of regulatory processes that are specifically involved in the biofilm mode of life. In particular, bacterial cell to cell signaling called “Quorum Sensing” together with intracellular signaling by bis-(3′-5′-cyclic-dimeric guanosine monophosphate (cyclic-di-GMP have gained a lot of attention over the last two decades. More recently, regulatory processes governed by two component regulatory systems and small non-coding RNAs have been increasingly investigated. Here, we review novel findings and potentials of using small molecules to target and modulate these regulatory processes in the bacterium Pseudomonas aeruginosa to decrease its pathogenic potential.

  11. Control theory meets synthetic biology.

    Science.gov (United States)

    Del Vecchio, Domitilla; Dy, Aaron J; Qian, Yili

    2016-07-01

    The past several years have witnessed an increased presence of control theoretic concepts in synthetic biology. This review presents an organized summary of how these control design concepts have been applied to tackle a variety of problems faced when building synthetic biomolecular circuits in living cells. In particular, we describe success stories that demonstrate how simple or more elaborate control design methods can be used to make the behaviour of synthetic genetic circuits within a single cell or across a cell population more reliable, predictable and robust to perturbations. The description especially highlights technical challenges that uniquely arise from the need to implement control designs within a new hardware setting, along with implemented or proposed solutions. Some engineering solutions employing complex feedback control schemes are also described, which, however, still require a deeper theoretical analysis of stability, performance and robustness properties. Overall, this paper should help synthetic biologists become familiar with feedback control concepts as they can be used in their application area. At the same time, it should provide some domain knowledge to control theorists who wish to enter the rising and exciting field of synthetic biology. © 2016 The Author(s).

  12. Key Issues Concerning Biolog Use for Aerobic and Anaerobic Freshwater Bacterial Community-Level Physiological Profiling

    Science.gov (United States)

    Christian, Bradley W.; Lind, Owen T.

    2006-06-01

    Bacterial heterotrophy in aquatic ecosystems is important in the overall carbon cycle. Biolog MicroPlates provide information into the metabolic potential of bacteria involved in carbon cycling. Specifically, Biolog EcoPlatesTM were developed with ecologically relevant carbon substrates to allow investigators to measure carbon substrate utilization patterns and develop community-level physiological profiles from natural bacterial assemblages. However, understanding of the functionality of these plates in freshwater research is limited. We explored several issues of EcoPlate use for freshwater bacterial assemblages including inoculum density, incubation temperature, non-bacterial color development, and substrate selectivity. Each of these has various effects on plate interpretation. We offer suggestions and techniques to resolve these interpretation issues. Lastly we propose a technique to allow EcoPlate use in anaerobic freshwater bacterial studies.

  13. Control of intestinal bacterial proliferation in regulation of lifespan in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Portal-Celhay Cynthia

    2012-03-01

    Full Text Available Abstract Background A powerful approach to understanding complex processes such as aging is to use model organisms amenable to genetic manipulation, and to seek relevant phenotypes to measure. Caenorhabditis elegans is particularly suited to studies of aging, since numerous single-gene mutations have been identified that affect its lifespan; it possesses an innate immune system employing evolutionarily conserved signaling pathways affecting longevity. As worms age, bacteria accumulate in the intestinal tract. However, quantitative relationships between worm genotype, lifespan, and intestinal lumen bacterial load have not been examined. We hypothesized that gut immunity is less efficient in older animals, leading to enhanced bacterial accumulation, reducing longevity. To address this question, we evaluated the ability of worms to control bacterial accumulation as a functional marker of intestinal immunity. Results We show that as adult worms age, several C. elegans genotypes show diminished capacity to control intestinal bacterial accumulation. We provide evidence that intestinal bacterial load, regulated by gut immunity, is an important causative factor of lifespan determination; the effects are specified by bacterial strain, worm genotype, and biologic age, all acting in concert. Conclusions In total, these studies focus attention on the worm intestine as a locus that influences longevity in the presence of an accumulating bacterial population. Further studies defining the interplay between bacterial species and host immunity in C. elegans may provide insights into the general mechanisms of aging and age-related diseases.

  14. "Protected biological control"- Biological pest management in the greenhouse industry

    NARCIS (Netherlands)

    Pilkington, L.J.; Messelink, G.J.; Lenteren, van J.C.; Mottee, Le K.

    2010-01-01

    This paper briefly describes the foundations and characteristics of biological control in protected cropping and what drivers are behind adoption of this management system within this industry. Examining a brief history of biological control in greenhouses and what makes it a successful management

  15. Recent Trends in Control Methods for Bacterial Wilt Diseases Caused by Ralstonia solanacearum

    Science.gov (United States)

    Yuliar; Nion, Yanetri Asi; Toyota, Koki

    2015-01-01

    Previous studies have described the development of control methods against bacterial wilt diseases caused by Ralstonia solanacearum. This review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. Biological control agents (BCAs) have been dominated by bacteria (90%) and fungi (10%). Avirulent strains of R. solanacearum, Pseudomonas spp., Bacillus spp., and Streptomyces spp. are well-known BCAs. New or uncommon BCAs have also been identified such as Acinetobacter sp., Burkholderia sp., and Paenibacillus sp. Inoculation methods for BCAs affect biocontrol efficacy, such as pouring or drenching soil, dipping of roots, and seed coatings. The amendment of different organic matter, such as plant residue, animal waste, and simple organic compounds, have frequently been reported to suppress bacterial wilt diseases. The combined application of BCAs and their substrates was shown to more effectively suppress bacterial wilt in the tomato. Suppression mechanisms are typically attributed to the antibacterial metabolites produced by BCAs or those present in natural products; however, the number of studies related to host resistance to the pathogen is increasing. Enhanced/modified soil microbial communities are also indirectly involved in disease suppression. New promising types of control measures include biological soil disinfection using substrates that release volatile compounds. This review described recent advances in different control measures. We focused on the importance of integrated pest management (IPM) for bacterial wilt diseases. PMID:25762345

  16. Biological stability of drinking water: controlling factors, methods and challenges

    Directory of Open Access Journals (Sweden)

    Emmanuelle ePrest

    2016-02-01

    Full Text Available Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g. development of opportunistic pathogens, aesthetic (e.g. deterioration of taste, odour, colour or operational (e.g. fouling or biocorrosion of pipes problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors such as (i type and concentration of available organic and inorganic nutrients, (ii type and concentration of residual disinfectant, (iii presence of predators such as protozoa and invertebrates, (iv environmental conditions such as water temperature, and (v spatial location of microorganisms (bulk water, sediment or biofilm. Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i existing knowledge on biological stability controlling factors and (ii how these factors are affected by drinking water production and distribution conditions. In addition, (iii the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discuss how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to

  17. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    Science.gov (United States)

    Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  18. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    KAUST Repository

    Prest, Emmanuelle I.

    2016-02-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  19. Biological control and sustainable food production

    NARCIS (Netherlands)

    Bale, J.S.; Lenteren, van J.C.; Bigler, F.

    2008-01-01

    The use of biological control for the management of pest insects pre-dates the modern pesticide era. The first major successes in biological control occurred with exotic pests controlled by natural enemy species collected from the country or area of origin of the pest (classical control).

  20. Transcription control engineering and applications in synthetic biology

    Directory of Open Access Journals (Sweden)

    Michael D. Engstrom

    2017-09-01

    Full Text Available In synthetic biology, researchers assemble biological components in new ways to produce systems with practical applications. One of these practical applications is control of the flow of genetic information (from nucleic acid to protein, a.k.a. gene regulation. Regulation is critical for optimizing protein (and therefore activity levels and the subsequent levels of metabolites and other cellular properties. The central dogma of molecular biology posits that information flow commences with transcription, and accordingly, regulatory tools targeting transcription have received the most attention in synthetic biology. In this mini-review, we highlight many past successes and summarize the lessons learned in developing tools for controlling transcription. In particular, we focus on engineering studies where promoters and transcription terminators (cis-factors were directly engineered and/or isolated from DNA libraries. We also review several well-characterized transcription regulators (trans-factors, giving examples of how cis- and trans-acting factors have been combined to create digital and analogue switches for regulating transcription in response to various signals. Last, we provide examples of how engineered transcription control systems have been used in metabolic engineering and more complicated genetic circuits. While most of our mini-review focuses on the well-characterized bacterium Escherichia coli, we also provide several examples of the use of transcription control engineering in non-model organisms. Similar approaches have been applied outside the bacterial kingdom indicating that the lessons learned from bacterial studies may be generalized for other organisms.

  1. Transcription control engineering and applications in synthetic biology.

    Science.gov (United States)

    Engstrom, Michael D; Pfleger, Brian F

    2017-09-01

    In synthetic biology, researchers assemble biological components in new ways to produce systems with practical applications. One of these practical applications is control of the flow of genetic information (from nucleic acid to protein), a.k.a. gene regulation. Regulation is critical for optimizing protein (and therefore activity) levels and the subsequent levels of metabolites and other cellular properties. The central dogma of molecular biology posits that information flow commences with transcription, and accordingly, regulatory tools targeting transcription have received the most attention in synthetic biology. In this mini-review, we highlight many past successes and summarize the lessons learned in developing tools for controlling transcription. In particular, we focus on engineering studies where promoters and transcription terminators ( cis -factors) were directly engineered and/or isolated from DNA libraries. We also review several well-characterized transcription regulators ( trans- factors), giving examples of how cis- and trans -acting factors have been combined to create digital and analogue switches for regulating transcription in response to various signals. Last, we provide examples of how engineered transcription control systems have been used in metabolic engineering and more complicated genetic circuits. While most of our mini-review focuses on the well-characterized bacterium Escherichia coli , we also provide several examples of the use of transcription control engineering in non-model organisms. Similar approaches have been applied outside the bacterial kingdom indicating that the lessons learned from bacterial studies may be generalized for other organisms.

  2. Construction of Biologically Functional Bacterial Plasmids In Vitro

    Science.gov (United States)

    Cohen, Stanley N.; Chang, Annie C. Y.; Boyer, Herbert W.; Helling, Robert B.

    1973-01-01

    The construction of new plasmid DNA species by in vitro joining of restriction endonuclease-generated fragments of separate plasmids is described. Newly constructed plasmids that are inserted into Escherichia coli by transformation are shown to be biologically functional replicons that possess genetic properties and nucleotide base sequences from both of the parent DNA molecules. Functional plasmids can be obtained by reassociation of endonuclease-generated fragments of larger replicons, as well as by joining of plasmid DNA molecules of entirely different origins. Images PMID:4594039

  3. Biology and Water Pollution Control.

    Science.gov (United States)

    Warren, Charles E.

    Within this text, the reader is attuned to the role biology can and should play in combating the alarming increase in water pollution. Both the urgency of the problem and the biological techniques that are being developed to cope with the water pollution crisis are scrutinized; what is and is not known about the problem is explained; past,…

  4. Biological Control in Brazil: an overview

    OpenAIRE

    Parra,José Roberto Postali

    2014-01-01

    The use of Biological Control methods is on the increase, mainly as a result of the mobilization of human resources in entomology studies since the establishment of graduate programs in this country in the 1960s. This review approaches the retrospective of Biological Control in Brazil in recent decades, with an emphasis on the "culture of applying agrochemicals" adopted by Brazilian growers, which constrains progress in this area. Successful cases of Biological Control have been reported on i...

  5. Modeling of the bacterial mechanism of methicillin-resistance by a systems biology approach.

    Directory of Open Access Journals (Sweden)

    Ida Autiero

    Full Text Available BACKGROUND: A microorganism is a complex biological system able to preserve its functional features against external perturbations and the ability of the living systems to oppose to these external perturbations is defined "robustness". The antibiotic resistance, developed by different bacteria strains, is a clear example of robustness and of ability of the bacterial system to acquire a particular functional behaviour in response to environmental changes. In this work we have modeled the whole mechanism essential to the methicillin-resistance through a systems biology approach. The methicillin is a beta-lactamic antibiotic that act by inhibiting the penicillin-binding proteins (PBPs. These PBPs are involved in the synthesis of peptidoglycans, essential mesh-like polymers that surround cellular enzymes and are crucial for the bacterium survival. METHODOLOGY: The network of genes, mRNA, proteins and metabolites was created using CellDesigner program and the data of molecular interactions are stored in Systems Biology Markup Language (SBML. To simulate the dynamic behaviour of this biochemical network, the kinetic equations were associated with each reaction. CONCLUSIONS: Our model simulates the mechanism of the inactivation of the PBP by methicillin, as well as the expression of PBP2a isoform, the regulation of the SCCmec elements (SCC: staphylococcal cassette chromosome and the synthesis of peptidoglycan by PBP2a. The obtained results by our integrated approach show that the model describes correctly the whole phenomenon of the methicillin resistance and is able to respond to the external perturbations in the same way of the real cell. Therefore, this model can be useful to develop new therapeutic approaches for the methicillin control and to understand the general mechanism regarding the cellular resistance to some antibiotics.

  6. Tiny cells meet big questions: a closer look at bacterial cell biology.

    Science.gov (United States)

    Goley, Erin D

    2013-04-01

    While studying actin assembly as a graduate student with Matt Welch at the University of California at Berkeley, my interest was piqued by reports of surprising observations in bacteria: the identification of numerous cytoskeletal proteins, actin homologues fulfilling spindle-like functions, and even the presence of membrane-bound organelles. Curiosity about these phenomena drew me to Lucy Shapiro's lab at Stanford University for my postdoctoral research. In the Shapiro lab, and now in my lab at Johns Hopkins, I have focused on investigating the mechanisms of bacterial cytokinesis. Spending time as both a eukaryotic cell biologist and a bacterial cell biologist has convinced me that bacterial cells present the same questions as eukaryotic cells: How are chromosomes organized and accurately segregated? How is force generated for cytokinesis? How is polarity established? How are signals transduced within and between cells? These problems are conceptually similar between eukaryotes and bacteria, although their solutions can differ significantly in specifics. In this Perspective, I provide a broad view of cell biological phenomena in bacteria, the technical challenges facing those of us who peer into bacterial cells, and areas of common ground as research in eukaryotic and bacterial cell biology moves forward.

  7. Engineering a palette of eukaryotic chromoproteins for bacterial synthetic biology.

    Science.gov (United States)

    Liljeruhm, Josefine; Funk, Saskia K; Tietscher, Sandra; Edlund, Anders D; Jamal, Sabri; Wistrand-Yuen, Pikkei; Dyrhage, Karl; Gynnå, Arvid; Ivermark, Katarina; Lövgren, Jessica; Törnblom, Viktor; Virtanen, Anders; Lundin, Erik R; Wistrand-Yuen, Erik; Forster, Anthony C

    2018-01-01

    Coral reefs are colored by eukaryotic chromoproteins (CPs) that are homologous to green fluorescent protein. CPs differ from fluorescent proteins (FPs) by intensely absorbing visible light to give strong colors in ambient light. This endows CPs with certain advantages over FPs, such as instrument-free detection uncomplicated by ultra-violet light damage or background fluorescence, efficient Förster resonance energy transfer (FRET) quenching, and photoacoustic imaging. Thus, CPs have found utility as genetic markers and in teaching, and are attractive for potential cell biosensor applications in the field. Most near-term applications of CPs require expression in a different domain of life: bacteria. However, it is unclear which of the eukaryotic CP genes might be suitable and how best to assay them. Here, taking advantage of codon optimization programs in 12 cases, we engineered 14 CP sequences (meffRed, eforRed, asPink, spisPink, scOrange, fwYellow, amilGFP, amajLime, cjBlue, meffBlue, aeBlue, amilCP, tsPurple and gfasPurple) into a palette of Escherichia coli BioBrick plasmids. BioBricks comply with synthetic biology's most widely used, simplified, cloning standard. Differences in color intensities, maturation times and fitness costs of expression were compared under the same conditions, and visible readout of gene expression was quantitated. A surprisingly large variation in cellular fitness costs was found, resulting in loss of color in some overnight liquid cultures of certain high-copy-plasmid-borne CPs, and cautioning the use of multiple CPs as markers in competition assays. We solved these two problems by integrating pairs of these genes into the chromosome and by engineering versions of the same CP with very different colors. Availability of 14 engineered CP genes compared in E. coli , together with chromosomal mutants suitable for competition assays, should simplify and expand CP study and applications. There was no single plasmid-borne CP that combined

  8. Electrokinetic and optical control of bacterial microrobots

    International Nuclear Information System (INIS)

    Steager, Edward B; Kim, Dal Hyung; Kim, Min Jun; Sakar, Mahmut Selman; Kumar, Vijay; Pappas, George J

    2011-01-01

    One of the great challenges in microscale science and engineering is the independent manipulation of cells and man-made objects on the micron scale. For such work, motile microorganisms are integrated with engineered systems to construct microbiorobots (MBRs). MBRs are negative photosensitive epoxy (SU-8) microfabricated structures with typical feature sizes ranging from 1 to 100 µm coated with a monolayer of swarmer cells of the bacterium Serratia marcescens. The adherent cells naturally coordinate to propel the microstructures in fluidic environments. In this study, ultraviolet light is used to control rotational motion and direct current electric fields are used to control the two-dimensional movement of MBRs. They are steered in a fully automated fashion using computer-controlled visual servoing, used to transport and manipulate micron-sized objects, and employed as cell-based biosensors. This work is a step toward in vitro mechanical or chemical manipulation of cells as well as controlled assembly of microcomponents.

  9. Feedback control architecture and the bacterial chemotaxis network.

    Directory of Open Access Journals (Sweden)

    Abdullah Hamadeh

    2011-05-01

    Full Text Available Bacteria move towards favourable and away from toxic environments by changing their swimming pattern. This response is regulated by the chemotaxis signalling pathway, which has an important feature: it uses feedback to 'reset' (adapt the bacterial sensing ability, which allows the bacteria to sense a range of background environmental changes. The role of this feedback has been studied extensively in the simple chemotaxis pathway of Escherichia coli. However it has been recently found that the majority of bacteria have multiple chemotaxis homologues of the E. coli proteins, resulting in more complex pathways. In this paper we investigate the configuration and role of feedback in Rhodobacter sphaeroides, a bacterium containing multiple homologues of the chemotaxis proteins found in E. coli. Multiple proteins could produce different possible feedback configurations, each having different chemotactic performance qualities and levels of robustness to variations and uncertainties in biological parameters and to intracellular noise. We develop four models corresponding to different feedback configurations. Using a series of carefully designed experiments we discriminate between these models and invalidate three of them. When these models are examined in terms of robustness to noise and parametric uncertainties, we find that the non-invalidated model is superior to the others. Moreover, it has a 'cascade control' feedback architecture which is used extensively in engineering to improve system performance, including robustness. Given that the majority of bacteria are known to have multiple chemotaxis pathways, in this paper we show that some feedback architectures allow them to have better performance than others. In particular, cascade control may be an important feature in achieving robust functionality in more complex signalling pathways and in improving their performance.

  10. Biological Systems Thinking for Control Engineering Design

    Directory of Open Access Journals (Sweden)

    D. J. Murray-Smith

    2004-01-01

    Full Text Available Artificial neural networks and genetic algorithms are often quoted in discussions about the contribution of biological systems thinking to engineering design. This paper reviews work on the neuromuscular system, a field in which biological systems thinking could make specific contributions to the development and design of automatic control systems for mechatronics and robotics applications. The paper suggests some specific areas in which a better understanding of this biological control system could be expected to contribute to control engineering design methods in the future. Particular emphasis is given to the nonlinear nature of elements within the neuromuscular system and to processes of neural signal processing, sensing and system adaptivity. Aspects of the biological system that are of particular significance for engineering control systems include sensor fusion, sensor redundancy and parallelism, together with advanced forms of signal processing for adaptive and learning control

  11. BSim: an agent-based tool for modeling bacterial populations in systems and synthetic biology.

    Directory of Open Access Journals (Sweden)

    Thomas E Gorochowski

    Full Text Available Large-scale collective behaviors such as synchronization and coordination spontaneously arise in many bacterial populations. With systems biology attempting to understand these phenomena, and synthetic biology opening up the possibility of engineering them for our own benefit, there is growing interest in how bacterial populations are best modeled. Here we introduce BSim, a highly flexible agent-based computational tool for analyzing the relationships between single-cell dynamics and population level features. BSim includes reference implementations of many bacterial traits to enable the quick development of new models partially built from existing ones. Unlike existing modeling tools, BSim fully considers spatial aspects of a model allowing for the description of intricate micro-scale structures, enabling the modeling of bacterial behavior in more realistic three-dimensional, complex environments. The new opportunities that BSim opens are illustrated through several diverse examples covering: spatial multicellular computing, modeling complex environments, population dynamics of the lac operon, and the synchronization of genetic oscillators. BSim is open source software that is freely available from http://bsim-bccs.sf.net and distributed under the Open Source Initiative (OSI recognized MIT license. Developer documentation and a wide range of example simulations are also available from the website. BSim requires Java version 1.6 or higher.

  12. Conserving and enhancing biological control of nematodes.

    Science.gov (United States)

    Timper, Patricia

    2014-06-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  13. Lake Bacterial Assemblage Composition Is Sensitive to Biological Disturbance Caused by an Invasive Filter Feeder.

    Science.gov (United States)

    Denef, Vincent J; Carrick, Hunter J; Cavaletto, Joann; Chiang, Edna; Johengen, Thomas H; Vanderploeg, Henry A

    2017-01-01

    One approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. Species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. Here, we studied direct impacts of invasive dreissenid mussels (IDMs), one of many invasive filter feeders, on freshwater lake bacterioplankton. We demonstrated that direct effects of IDMs reduced bacterial abundance and altered assemblage composition by preferentially removing larger and particle-associated bacteria. While this increased the relative abundances of many free-living bacterial taxa, some were susceptible to filter feeding, in line with efficient removal of phytoplankton cells of <2 μm. This selective removal of particle-associated and larger bacteria by IDMs altered inferred bacterial functional group representation, defined by carbon and energy source utilization. Specifically, we inferred an increased relative abundance of chemoorganoheterotrophs predicted to be capable of rhodopsin-dependent energy generation. In contrast to the few previous studies that have focused on the longer-term combined direct and indirect effects of IDMs on bacterioplankton, our study showed that IDMs act directly as a biological disturbance to which freshwater bacterial assemblages are sensitive. The negative impacts on particle-associated bacteria, which have been shown to be more active than free-living bacteria, and the inferred shifts in functional group representation raise the possibility that IDMs may directly alter bacterially mediated ecosystem functions. IMPORTANCE Freshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a variety of

  14. Opportunities for biological weed control in Europe

    NARCIS (Netherlands)

    Scheepens, P.C.; Müller-Schärer, H.; Kempenaar, C.

    2001-01-01

    The development and application of biological weed control offer greatopportunities not only for farmers, nature conservationists and othervegetation managers but also for institutions and companies that wish tosell plant protection services and products, and for the general publicthat demands safe

  15. Differential Control Efficacies of Vitamin Treatments against Bacterial Wilt and Grey Mould Diseases in Tomato Plants

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2016-10-01

    Full Text Available Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea, respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1, niacin (vitamin B3, pyridoxine (vitamin B6, and menadione (vitamin K3. In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure (10⁶ colony-forming unit [cfu]/ml. Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea. The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea. Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould.

  16. Differential Control Efficacies of Vitamin Treatments against Bacterial Wilt and Grey Mould Diseases in Tomato Plants.

    Science.gov (United States)

    Hong, Jeum Kyu; Kim, Hyeon Ji; Jung, Heesoo; Yang, Hye Ji; Kim, Do Hoon; Sung, Chang Hyun; Park, Chang-Jin; Chang, Seog Won

    2016-10-01

    Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea , respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1), niacin (vitamin B3), pyridoxine (vitamin B6), and menadione (vitamin K3). In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure (10 6 colony-forming unit [cfu]/ml). Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea . The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea . Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould.

  17. Mathematical Modelling of Bacterial Meningitis Transmission Dynamics with Control Measures

    Directory of Open Access Journals (Sweden)

    Joshua Kiddy K. Asamoah

    2018-01-01

    Full Text Available Vaccination and treatment are the most effective ways of controlling the transmission of most infectious diseases. While vaccination helps susceptible individuals to build either a long-term immunity or short-term immunity, treatment reduces the number of disease-induced deaths and the number of infectious individuals in a community/nation. In this paper, a nonlinear deterministic model with time-dependent controls has been proposed to describe the dynamics of bacterial meningitis in a population. The model is shown to exhibit a unique globally asymptotically stable disease-free equilibrium E0, when the effective reproduction number RVT≤1, and a globally asymptotically stable endemic equilibrium E1, when RVT>1; and it exhibits a transcritical bifurcation at RVT=1. Carriers have been shown (by Tornado plot to have a higher chance of spreading the infection than those with clinical symptoms who will sometimes be bound to bed during the acute phase of the infection. In order to find the best strategy for minimizing the number of carriers and ill individuals and the cost of control implementation, an optimal control problem is set up by defining a Lagrangian function L to be minimized subject to the proposed model. Numerical simulation of the optimal problem demonstrates that the best strategy to control bacterial meningitis is to combine vaccination with other interventions (such as treatment and public health education. Additionally, this research suggests that stakeholders should press hard for the production of existing/new vaccines and antibiotics and their disbursement to areas that are most affected by bacterial meningitis, especially Sub-Saharan Africa; furthermore, individuals who live in communities where the environment is relatively warm (hot/moisture are advised to go for vaccination against bacterial meningitis.

  18. Role of antimicrobial peptides in controlling symbiotic bacterial populations.

    Science.gov (United States)

    Mergaert, P

    2018-04-25

    Covering: up to 2018 Antimicrobial peptides (AMPs) have been known for well over three decades as crucial mediators of the innate immune response in animals and plants, where they are involved in the killing of infecting microbes. However, AMPs have now also been found to be produced by eukaryotic hosts during symbiotic interactions with bacteria. These symbiotic AMPs target the symbionts and therefore have a more subtle biological role: not eliminating the microbial symbiont population but rather keeping it in check. The arsenal of AMPs and the symbionts' adaptations to resist them are in a careful balance, which contributes to the establishment of the host-microbe homeostasis. Although in many cases the biological roles of symbiotic AMPs remain elusive, for a number of symbiotic interactions, precise functions have been assigned or proposed to the AMPs, which are discussed here. The microbiota living on epithelia in animals, from the most primitive ones to the mammals, are challenged by a cocktail of AMPs that determine the specific composition of the bacterial community as well as its spatial organization. In the symbiosis of legume plants with nitrogen-fixing rhizobium bacteria, the host deploys an extremely large panel of AMPs - called nodule-specific cysteine-rich (NCR) peptides - that drive the bacteria into a terminally differentiated state and manipulate the symbiont physiology to maximize the benefit for the host. The NCR peptides are used as tools to enslave the bacterial symbionts, limiting their reproduction but keeping them metabolically active for nitrogen fixation. In the nutritional symbiotic interactions of insects and protists that have vertically transmitted bacterial symbionts with reduced genomes, symbiotic AMPs could facilitate the integration of the endosymbiont and host metabolism by favouring the flow of metabolites across the symbiont membrane through membrane permeabilization.

  19. Bacterial membrane vesicles, an overlooked environmental colloid: Biology, environmental perspectives and applications.

    Science.gov (United States)

    Toyofuku, Masanori; Tashiro, Yosuke; Hasegawa, Yusuke; Kurosawa, Masaharu; Nomura, Nobuhiko

    2015-12-01

    Phospholipid vesicles play important roles in biological systems. Bacteria are one of the most abundant organisms on Earth, and bacterial membrane vesicles (MVs) were first observed 50 years ago. Many bacteria release MVs to the environment that mainly consist of the cell membrane and typically range from 20 to 400 nm in size. Bacterial MVs are involved in several biological functions, such as delivery of cargo, virulence and gene transfer. MVs can be isolated from laboratory culture and directly from the environment, indicating their high abundance in and impact on ecosystems. Many colloidal particles in the environment ranging in size from 1 nm to 1 μm have been reported but not characterized at the molecular level, and MVs remain to be explored. Hence, MVs can be considered terra incognita in environmental colloid research. Although MV biogenesis and biological roles are yet to be fully understood, the accumulation of knowledge has opened new avenues for their applications. Via genetic engineering, the MV yield can be greatly increased, and the components of MVs can be tailored. Recent studies have demonstrated that MVs have promising potential for applications such as drug delivery systems and nanobiocatalysts. For instance, MV vaccines have been extensively studied and have already been approved in Europe. Recent MV studies have evoked great interest in the fields of biology and biotechnology, but fundamental questions, such as their transport in the environment or physicochemical features of MVs, remain to be addressed. In this review, we present the current understanding of bacterial MVs and environmental perspectives and further introduce their applications. Copyright © 2015. Published by Elsevier B.V.

  20. Use of nuclear techniques in biological control

    International Nuclear Information System (INIS)

    Greany, Patrick D.; Carpenter, James E.

    2000-01-01

    As pointed out by Benbrook (1996), pest management is at a crossroads, and there is a great need for new, biointensive pest management strategies. Among these approaches, biological control is a keystone. However, because of increasing concerns about the introduction of exotic natural enemies of insect pests and weeds (Howarth 1991, Delfosse 1997), the overall thrust of biological control has moved toward augmentative biological control, involving releases of established natural enemy species (Knipling 1992). This in turn has created a need to develop more cost-effective mass rearing technologies for beneficial insects. Nuclear techniques could play an especially important role in augmentative biological control, not only in facilitating mass rearing, but in several other ways, as indicated below. Recognising the potential value for use of nuclear techniques in biological control, the Insect and Pest Control Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, sponsored a Consultants' Group Meeting on this subject in April 1997. The Group produced a document entitled Use of Nuclear Techniques in Biological Control: Managing Pests, Facilitating Trade and Protecting the Environment. The consultants included the authors of this paper as well as Ernest Delfosse (at that time, with the USDA-APHIS National Biological Control Institute), Garry Hill (Intl. Institute for Biological Control), Sinthya Penn (Beneficial Insectary), and Felipe Jeronimo (USDA-APHIS PPQ, Guatemala). The remarks presented in this paper reflect the thoughts presented by these consultants and other participants at the IAEA-sponsored meeting. Several potential uses for nuclear techniques were identified by the Consultants' Group, including: 1) improvements in rearing media (either artificial diets or natural hosts/prey), 2) provision of sterilised natural prey to be used as food during shipment, to ameliorate concerns relating to the

  1. Biological control component [Management of water hyacinth

    International Nuclear Information System (INIS)

    Harley, K.L.S.

    1981-01-01

    Both chemical and biological control have been used with limited success for the management of water hyacinth in Fiji. In some cases heavy application of chemicals have been successful in completely killing limited areas of water hyacinth, but have resulted in the destruction of biological agents introduced to control the water hyacinth and high contamination of natural water supplies. It is proposed that under the direction of Mr S R Singh, the Senior Research Scientist (Entomology) of the Koronivia Research Station, Suva, Fiji, a collaborative programme with Dr Harley of Australia on chemical and biological control of water hyacinth be initiated. This programme would be fundamentally short-term with the prime objective being an investigation of levels of insect population following varying levels of application of chemical sprays. By comparison with control areas, observations would be made of both chemical damage and insect damage within the limited time span of the period

  2. Use of biolog methodology for optimizing the degradation of hydrocarbons by bacterial consortia.

    Science.gov (United States)

    Ambrosoli, R; Bardi, L; Minati, J L; Belviso, S; Ricci, R; Marzona, M

    2003-01-01

    Biolog methodology was used for the preliminary screening of different cultural conditions in order to detect the best combination/s of factors influencing the metabolic performance of bacterial consortia active in the degradation of hydrocarbons. Two microbial consortia were tested for their activity on 2 hydrocarbons (nonadecane and eicosane) in presence of the following cultural coadjuvants: vegetal oil, beta-cyclodextrine, sodium acetate, mineral solution. Tests were conducted in Biolog MT plates, where only the redox indicator of microbial growth (tetrazolium violet) and no carbon sources are provided. The microwells were filled with various combinations of hydrocarbons, microbial inoculum and coadjuvants. Blanks were prepared with the same combinations but without hydrocarbons. The results obtained show the suitability of the methodology developed to identify the most active consortium and the conditions for its best degradation performance. The efficacy of Biolog methodology (Biolog Inc., USA) for the characterization of microbial communities on the basis of the metabolic profiles obtained on specific carbon sources in the microwells of Elisa-type plates, is widely acknowledged (Garland, 1997; Pietikäinen et al., 2000; Dauber and Wolters, 2000). Due to its aptitude to simultaneously evaluate multiple microbial responses and directly organize the results, it can be adapted to meet specific study purposes (Gamo and Shji, 1999). In the present research Biolog methodology was fitted for the preliminary screening of different cultural conditions, in order to detect the best combination/s of factors influencing the metabolic performance of bacterial consortia active in the degradation of aliphatic hydrocarbons, in view of their utilization for the bioremediation of polluted sites.

  3. Treatment for symptomatic bacterial vaginosis: a randomized controlled trial

    International Nuclear Information System (INIS)

    Tariq, N.; Basharat, A.; Fahim, A.

    2017-01-01

    Objective: To compare the efficacy of multiple doses of vaginal clindamycin with a single oral dose of secnidazole for the treatment of bacterial vaginosis. Study Design: Double-blinded randomized controlled trial. Place and Duration of Study: Shifa Foundation Community Health Center, from March 2012 till February 2015. Methodology: After obtaining written informed consent, a pelvic examination was performed for the confirmation of symptoms of milky white vaginal discharge on speculum examination, positive Amine test and presence of clue cells on microscopy. Pregnant women, known diabetes or any immunocompromised condition, were excluded. Blinding of the patient, doctor, and the pharmacist was done. Study cohort was then divided into two groups, Group A received medicine pack A which contained active clindamycin and placebo oral preparation, whereas group B was given pack B which contained active 2-gm secnidazole with placebo vaginal cream. Primary outcome and therapeutic success were defined by correction of two out of three (normal Nugent score, negative Amine test, and no milky white discharge) on day 15. Results: At 15th day of treatment, 96.6% participants in vaginal clindamycin group (Group A), recovered from the bacterial vaginosis; whereas, (group B) 23% patients were cured in oral secnidazole group. Conclusion: Multiple doses of vaginal clindamycin are superior to single dose of oral secnidazole for the treatment of bacterial vaginosis. (author)

  4. A functional overview of conservation biological control

    DEFF Research Database (Denmark)

    Begg, Graham S; Cook, Samantha M; Dye, Richard

    2017-01-01

    Conservation biological control (CBC) is a sustainable approach to pest management that can contribute to a reduction in pesticide use as part of an Integrated Pest Management (IPM) strategy. CBC is based on the premise that countering habitat loss and environmental disturbance associated...... CBC prescriptions have proved elusive. To tackle this, we consolidate existing knowledge of CBC using a simple conceptual model that organises the functional elements of CBC into a common, unifying framework. We identify and integrate the key biological processes affecting natural enemies...... and their biological control function across local and regional scales, and consider the interactions, interdependencies and constraints that determine the outcome of CBC strategies. Conservation measures are often effective in supporting natural enemy populations but their success cannot be guaranteed; the greatest...

  5. Design of a Comprehensive Biochemistry and Molecular Biology Experiment: Phase Variation Caused by Recombinational Regulation of Bacterial Gene Expression

    Science.gov (United States)

    Sheng, Xiumei; Xu, Shungao; Lu, Renyun; Isaac, Dadzie; Zhang, Xueyi; Zhang, Haifang; Wang, Huifang; Qiao, Zheng; Huang, Xinxiang

    2014-01-01

    Scientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about "Salmonella enterica" serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation,…

  6. Characterization and Control of Biological Microrobots

    NARCIS (Netherlands)

    Khalil, I.S.M.; Pichel, Marc Philippe; Pichel, M.P.; Zondervan, L.; Abelmann, Leon; Misra, Sarthak

    2012-01-01

    This work addresses the characterization and control of Magnetotactic Bacterium (MTB) which can be considered as a biological microrobot. Magnetic dipole moment of the MTB and response to a field-with-alternating-direction are characterized. First, the magnetic dipole moment is characterized using

  7. Characterization and control of biological microrobots

    NARCIS (Netherlands)

    Khalil, I.S.M.; Pichel, Marc Philippe; Zondervan, L.; Abelmann, Leon; Misra, Sarthak; Desai, Jaydev P.; Dudek, Gregory; Khatib, Oussama; Kumar, Vijay

    2013-01-01

    This work addresses the characterization and control of Magnetotactic Bacterium (MTB) which can be considered as a biological microrobot. Magnetic dipole moment of the MTB and response to a field-with-alternating-direction are characterized. First, the magnetic dipole moment is characterized using

  8. Incorporating biological control into IPM decision making

    Science.gov (United States)

    Of the many ways biological control can be incorporated into Integrated Pest Management (IPM) programs, natural enemy thresholds are arguably most easily adopted by stakeholders. Integration of natural enemy thresholds into IPM programs requires ecological and cost/benefit crop production data, thr...

  9. Selection of Trichogramma for inundative biological control

    NARCIS (Netherlands)

    Pak, G.A.

    1988-01-01

    This thesis presents a study of the potential for biological control of lepidopterous pests on cabbage crops in the Netherlands, by means of inundative releases of the egg parasite Trichogramma (Hymenoptera, Trichogrammatidae). The objective of this study is to investigate the

  10. Biological control of Meloidogyne incognita by Trichoderma ...

    African Journals Online (AJOL)

    Biological control against the root-knot nematode, Meloidogyne incognita was proven to occur in tomato, Solanum lycopersicom, soil-drenched with different isolates of Trichoderma harzianum and a commercial suspension of Serratia marcescens (Nemaless). The potential of such biocontrol agents to trigger plant defense ...

  11. Double network bacterial cellulose hydrogel to build a biology-device interface

    Science.gov (United States)

    Shi, Zhijun; Li, Ying; Chen, Xiuli; Han, Hongwei; Yang, Guang

    2013-12-01

    Establishing a biology-device interface might enable the interaction between microelectronics and biotechnology. In this study, electroactive hydrogels have been produced using bacterial cellulose (BC) and conducting polymer (CP) deposited on the BC hydrogel surface to cover the BC fibers. The structures of these composites thus have double networks, one of which is a layer of electroactive hydrogels combined with BC and CP. The electroconductivity provides the composites with capabilities for voltage and current response, and the BC hydrogel layer provides good biocompatibility, biodegradability, bioadhesion and mass transport properties. Such a system might allow selective biological functions such as molecular recognition and specific catalysis and also for probing the detailed genetic and molecular mechanisms of life. A BC-CP composite hydrogel could then lead to a biology-device interface. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) are used here to study the composite hydrogels' electroactive property. BC-PAni and BC-PPy respond to voltage changes. This provides a mechanism to amplify electrochemical signals for analysis or detection. BC hydrogels were found to be able to support the growth, spreading and migration of human normal skin fibroblasts without causing any cytotoxic effect on the cells in the cell culture. These double network BC-CP hydrogels are biphasic Janus hydrogels which integrate electroactivity with biocompatibility, and might provide a biology-device interface to produce implantable devices for personalized and regenerative medicine.

  12. Developmental Testing of Liquid and Gaseous/Vaporous Decontamination on Bacterial Spores and Other Biological Warfare Agents on Military Relevant Surfaces

    Science.gov (United States)

    2016-02-11

    Vaporous Decontamination on Bacterial Spores and Other Biological Warfare Agents on Military-Relevant Surfaces 5a. CONTRACT NUMBER 5b. GRANT... DECONTAMINATION ON BACTERIAL SPORES AND OTHER BIOLOGICAL WARFARE AGENTS ON MILITARY-RELEVANT SURFACES Page Paragraph 1. SCOPE...surfaces before and after decontamination . The protocol in this TOP is based on the developed test methodologies from Edgewood Chemical Biological

  13. Onchocerciasis control: biological research is still needed

    Directory of Open Access Journals (Sweden)

    Boussinesq M.

    2008-09-01

    Full Text Available Achievements obtained by the onchocerciasis control programmes should not lead to a relaxation in the biological research on Onchocerca volvulus. Issues such as the Loa loa-related postivermectin serious adverse events, the uncertainties as to whether onchocerciasis can be eliminated by ivermectin treatments, and the possible emergence of ivermectin-resistant O. volvulus populations should be addressed proactively. Doxycycline, moxidectin and emodepside appear to be promising as alternative drugs against onchocerciasis but support to researches in immunology and genomics should also be increased to develop new control tools, including both vaccines and macrofilaricidal drugs.

  14. Robust biological nitrogen fixation in a model grass-bacterial association.

    Science.gov (United States)

    Pankievicz, Vânia C S; do Amaral, Fernanda P; Santos, Karina F D N; Agtuca, Beverly; Xu, Youwen; Schueller, Michael J; Arisi, Ana Carolina M; Steffens, Maria B R; de Souza, Emanuel M; Pedrosa, Fábio O; Stacey, Gary; Ferrieri, Richard A

    2015-03-01

    Nitrogen-fixing rhizobacteria can promote plant growth; however, it is controversial whether biological nitrogen fixation (BNF) from associative interaction contributes to growth promotion. The roots of Setaria viridis, a model C4 grass, were effectively colonized by bacterial inoculants resulting in a significant enhancement of growth. Nitrogen-13 tracer studies provided direct evidence for tracer uptake by the host plant and incorporation into protein. Indeed, plants showed robust growth under nitrogen-limiting conditions when inoculated with an ammonium-excreting strain of Azospirillum brasilense. (11)C-labeling experiments showed that patterns in central carbon metabolism and resource allocation exhibited by nitrogen-starved plants were largely reversed by bacterial inoculation, such that they resembled plants grown under nitrogen-sufficient conditions. Adoption of S. viridis as a model should promote research into the mechanisms of associative nitrogen fixation with the ultimate goal of greater adoption of BNF for sustainable crop production. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  15. Bacterial Microcolonies in Gel Beads for High-Throughput Screening of Libraries in Synthetic Biology.

    Science.gov (United States)

    Duarte, José M; Barbier, Içvara; Schaerli, Yolanda

    2017-11-17

    Synthetic biologists increasingly rely on directed evolution to optimize engineered biological systems. Applying an appropriate screening or selection method for identifying the potentially rare library members with the desired properties is a crucial step for success in these experiments. Special challenges include substantial cell-to-cell variability and the requirement to check multiple states (e.g., being ON or OFF depending on the input). Here, we present a high-throughput screening method that addresses these challenges. First, we encapsulate single bacteria into microfluidic agarose gel beads. After incubation, they harbor monoclonal bacterial microcolonies (e.g., expressing a synthetic construct) and can be sorted according their fluorescence by fluorescence activated cell sorting (FACS). We determine enrichment rates and demonstrate that we can measure the average fluorescent signals of microcolonies containing phenotypically heterogeneous cells, obviating the problem of cell-to-cell variability. Finally, we apply this method to sort a pBAD promoter library at ON and OFF states.

  16. Adamantoylated biologically active small peptides and glycopeptides structurally related to the bacterial peptidoglycan.

    Science.gov (United States)

    Frkanec, Ruža; Vranešić, Branka; Tomić, Srdjanka

    2013-01-01

    A large number of novel synthetic compounds representing smaller parts of original peptidoglycan molecules have been synthesized and found to possess versatile biological activity, particularly immunomodulating properties. A series of compounds containing the adamantyl residues coupled to peptides and glycopeptides characteristic for bacterial peptidoglycan was described. The new adamantylpeptides and adamantylglycopeptides were prepared starting from N-protected racemic adamantylglycine and dipeptide L-Ala-D-isoglutamine. The adamantyl glycopeptides were obtained by coupling the adamantyltripeptides with alpha-D-mannose moiety through spacer molecule of fixed chirality. Since the starting material was D,L-(adamantyl-glycine) the condensation products with the dipeptide were mixtures of diastereoisomers. The obtained diastereoisomers were separated, characterized, and tested for immunostimulating activity. An HPLC method for purity testing was developed and adapted for the particular compounds.

  17. BIOLOGICAL CONTROL OF WEEDS BY MEANS OF PLANT PATHOGENS

    OpenAIRE

    Marija Ravlić; Renata Baličević

    2014-01-01

    Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, conservation and augmentative (inoculative and inundated) biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides) or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chem...

  18. Recent trends of modern bacterial insecticides for pest control practice in integrated crop management system.

    Science.gov (United States)

    Chattopadhyay, Pritam; Banerjee, Goutam; Mukherjee, Sayantan

    2017-05-01

    Food security and safety are the major concern in ever expanding human population on the planet earth. Each and every year insect pests cause a serious damage in agricultural field that cost billions of dollars annually to farmers. The loss in term of productivity and high cost of chemical pesticides enhance the production cost. Irrespective use of chemical pesticides (such as Benzene hexachloride, Endosulfan, Aldicarb, and Fenobucarb) in agricultural field raised several types of environmental issues. Furthermore, continuous use of chemical pesticides creates a selective pressure which helps in emerging of resistance pest. These excess chemical pesticide residues also contaminate the environment including the soil and water. Therefore, the biological control of insect pest in the agricultural field gains more importance due to food safety and environment friendly nature. In this regard, bacterial insecticides offer better alternative to chemical pesticides. It not only helps to establish food security through fighting against insect pests but also ensure the food safety. In this review, we have categorized insect pests and the corresponding bacterial insecticides, and critically analyzed the importance and mode of action of bacterial pesticides. We also have summarized the use of biopesticides in integrated pest management system. We have tried to focus the future research area in this field for the upcoming scientists.

  19. Augmenting Plant Immune Responses and Biological Control by Microbial Determinants

    Directory of Open Access Journals (Sweden)

    Sang Moo Lee

    2015-09-01

    Full Text Available Plant have developed sophisticated defence mechanisms against microbial pathogens. The recent accumulated information allow us to understand the nature of plant immune responses followed by recognition of microbial factors/determinants through cutting-edge genomics and multi-omics techniques. However, the practical approaches to sustain plant health using enhancement of plant immunity is yet to be fully appreciated. Here, we overviewed the general concept and representative examples on the plant immunity. The fungal, bacterial, and viral determinants that was previously reported as the triggers of plant immune responses are introduced and described as the potential protocol of biological control. Specifically, the role of chitin, glucan, lipopolysaccharides/extracellular polysaccharides, microbe/pathogen-associated molecular pattern, antibiotics, mimic-phytohormones, N-acyl homoserine lactone, harpin, vitamins, and volatile organic compounds are considered. We hope that this review stimulates scientific community and farmers to broaden their knowledge on the microbial determinant-based biological control and to apply the technology on the integrated pest management program.

  20. Wiring Together Synthetic Bacterial Consortia to Create a Biological Integrated Circuit.

    Science.gov (United States)

    Perry, Nicolas; Nelson, Edward M; Timp, Gregory

    2016-12-16

    The promise of adapting biology to information processing will not be realized until engineered gene circuits, operating in different cell populations, can be wired together to express a predictable function. Here, elementary biological integrated circuits (BICs), consisting of two sets of transmitter and receiver gene circuit modules with embedded memory placed in separate cell populations, were meticulously assembled using live cell lithography and wired together by the mass transport of quorum-sensing (QS) signal molecules to form two isolated communication links (comlinks). The comlink dynamics were tested by broadcasting "clock" pulses of inducers into the networks and measuring the responses of functionally linked fluorescent reporters, and then modeled through simulations that realistically captured the protein production and molecular transport. These results show that the comlinks were isolated and each mimicked aspects of the synchronous, sequential networks used in digital computing. The observations about the flow conditions, derived from numerical simulations, and the biofilm architectures that foster or silence cell-to-cell communications have implications for everything from decontamination of drinking water to bacterial virulence.

  1. Physical descriptions of the bacterial nucleoid at large scales, and their biological implications

    Energy Technology Data Exchange (ETDEWEB)

    Benza, Vincenzo G [Dipartimento di Fisica e Matematica, Universita dell' Insubria, Como (Italy); Bassetti, Bruno [Universita degli Studi di Milano, Dip. Fisica, Via Celoria 16, 20133 Milano (Italy); Dorfman, Kevin D [Department of Chemical Engineering and Materials Science, University of Minnesota-Twin Cities, 421 Washington Ave. SE, Minneapolis, MN 55455 (United States); Scolari, Vittore F; Lagomarsino, Marco Cosentino [CNRS, UMR 7238 ' Microorganism Genomics' , Genomic Physics Group (France); Bromek, Krystyna; Cicuta, Pietro [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom)

    2012-07-15

    Recent experimental and theoretical approaches have attempted to quantify the physical organization (compaction and geometry) of the bacterial chromosome with its complement of proteins (the nucleoid). The genomic DNA exists in a complex and dynamic protein-rich state, which is highly organized at various length scales. This has implications for modulating (when not directly enabling) the core biological processes of replication, transcription and segregation. We overview the progress in this area, driven in the last few years by new scientific ideas and new interdisciplinary experimental techniques, ranging from high space- and time-resolution microscopy to high-throughput genomics employing sequencing to map different aspects of the nucleoid-related interactome. The aim of this review is to present the wide spectrum of experimental and theoretical findings coherently, from a physics viewpoint. In particular, we highlight the role that statistical and soft condensed matter physics play in describing this system of fundamental biological importance, specifically reviewing classic and more modern tools from the theory of polymers. We also discuss some attempts toward unifying interpretations of the current results, pointing to possible directions for future investigation. (review article)

  2. Biological control of Fusarium moniliforme in maize.

    Science.gov (United States)

    Bacon, C W; Yates, I E; Hinton, D M; Meredith, F

    2001-05-01

    Fusarium moniliforme Sheldon, a biological species of the mating populations within the (italic)Gibberella fujikuroi species complex, i.e., population A [= G. moniliformis (Sheld.) Wineland], is an example of a facultative fungal endophyte. During the biotrophic endophytic association with maize, as well as during saprophytic growth, F. moniliforme produces the fumonisins. The fungus is transmitted vertically and horizontally to the next generation of plants via clonal infection of seeds and plant debris. Horizontal infection is the manner by which this fungus is spread contagiously and through which infection occurs from the outside that can be reduced by application of certain fungicides. The endophytic phase is vertically transmitted. This type infection is important because it is not controlled by seed applications of fungicides, and it remains the reservoir from which infection and toxin biosynthesis takes place in each generation of plants. Thus, vertical transmission of this fungus is just as important as horizontal transmission. A biological control system using an endophytic bacterium, Bacillus subtilis, has been developed that shows great promise for reducing mycotoxin accumulation during the endophytic (vertical transmission) growth phase. Because this bacterium occupies the identical ecological niche within the plant, it is considered an ecological homologue to F. moniliforme, and the inhibitory mechanism, regardless of the mode of action, operates on the competitive exclusion principle. In addition to this bacterium, an isolate of a species of the fungus Trichoderma shows promise in the postharvest control of the growth and toxin accumulation from F. moniliforme on corn in storage.

  3. An Integrated Biological Control System At Hanford

    International Nuclear Information System (INIS)

    Johnson, A.R.; Caudill, J.G.; Giddings, R.F.; Rodriguez, J.M.; Roos, R.C.; Wilde, J.W.

    2010-01-01

    In 1999 an integrated biological control system was instituted at the U.S. Department of Energy's Hanford Site. Successes and changes to the program needed to be communicated to a large and diverse mix of organizations and individuals. Efforts at communication are directed toward the following: Hanford Contractors (Liquid or Tank Waste, Solid Waste, Environmental Restoration, Science and Technology, Site Infrastructure), General Hanford Employees, and Hanford Advisory Board (Native American Tribes, Environmental Groups, Local Citizens, Washington State and Oregon State regulatory agencies). Communication was done through direct interface meetings, individual communication, where appropriate, and broadly sharing program reports. The objectives of the communication efforts was to have the program well coordinated with Hanford contractors, and to have the program understood well enough that all stakeholders would have confidence in the work performed by the program to reduce or elimate spread of radioactive contamination by biotic vectors. Communication of successes and changes to an integrated biological control system instituted in 1999 at the Department of Energy's Hanford Site have required regular interfaces with not only a diverse group of Hanford contractors (i.e., those responsible for liquid or tank waste, solid wastes, environmental restoration, science and technology, and site infrastructure), and general Hanford employees, but also with a consortium of designated stake holders organized as the Hanford Advisory Board (i.e., Native American tribes, various environmental groups, local citizens, Washington state and Oregon regulatory agencies, etc.). Direct interface meetings, individual communication where appropriate, and transparency of the biological control program were the methods and outcome of this effort.

  4. AN INTEGRATED BIOLOGICAL CONTROL SYSTEM AT HANFORD

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON AR; CAUDILL JG; GIDDINGS RF; RODRIGUEZ JM; ROOS RC; WILDE JW

    2010-02-11

    In 1999 an integrated biological control system was instituted at the U.S. Department of Energy's Hanford Site. Successes and changes to the program needed to be communicated to a large and diverse mix of organizations and individuals. Efforts at communication are directed toward the following: Hanford Contractors (Liquid or Tank Waste, Solid Waste, Environmental Restoration, Science and Technology, Site Infrastructure), General Hanford Employees, and Hanford Advisory Board (Native American Tribes, Environmental Groups, Local Citizens, Washington State and Oregon State regulatory agencies). Communication was done through direct interface meetings, individual communication, where appropriate, and broadly sharing program reports. The objectives of the communication efforts was to have the program well coordinated with Hanford contractors, and to have the program understood well enough that all stakeholders would have confidence in the work performed by the program to reduce or elimated spread of radioactive contamination by biotic vectors. Communication of successes and changes to an integrated biological control system instituted in 1999 at the Department of Energy's Hanford Site have required regular interfaces with not only a diverse group of Hanford contractors (i.e., those responsible for liquid or tank waste, solid wastes, environmental restoration, science and technology, and site infrastructure), and general Hanford employees, but also with a consortium of designated stake holders organized as the Hanford Advisory Board (i.e., Native American tribes, various environmental groups, local citizens, Washington state and Oregon regulatory agencies, etc.). Direct interface meetings, individual communication where appropriate, and transparency of the biological control program were the methods and outcome of this effort.

  5. Biological control of corky root in tomato.

    Science.gov (United States)

    Fiume, G; Fiume, F

    2008-01-01

    Corky root caused by Pyrenochaeta lycopersici (Schneider et Gerlach) is one of the most important soil borne fungal pathogens which develops in the soils, causing diseases in different crops. The research was carried out to evaluate the effectiveness of the biological control of corky root on tomato. Biological control was performed by using Trichoderma viride Pers. 18/17 SS, Streptomyces spp. AtB42 and Bacillus subtilis M51 PI. According to present and future regulations on the use of chemical fungicides and considering that treatments must avoids environmental pollution, the main object of this research was to find alternative strategies by using biocontrol agents against P. lycopersici that affect tomato plants. In laboratory, the effectiveness of T. viride 18/17 SS, Streptomyces spp. AtB42 and B. subtilis M51 PI to control P. lycopersici were studied. In greenhouse, the research was carried out comparing the following treatments: 1) untreated control; 2) T. viride 18/17 SS; 3) Streptomyces spp. AtB42; 4) B. subtilis M51 PI. Roots of plants of tomato H3028 Hazera were treated with the antagonist suspensions just prior of transplant. Treatments were repeated about 2 months after, with the same suspensions sprayed on the soil to the plant collar. In dual culture, the inhibition of P. lycopersici ranged up to 81.2% (caused from T. viride 18/17 SS), 75.6% (from Streptomyces spp. AtB42) and 66.8% (from B. subtilis M51 PI). In greenhouse trials, with regard to corky root symptoms, all treated plots showed signifycative differences compared to untreated. T. viride gave the better results followed by Streptomyces spp. and then by B. subtilis. The fungus antagonist showed good root surface competence such as demonstrated its persistence on the roots surface of the tomato plants whose roots were treated with T. viride 18/17 SS up to 2 months before.

  6. Biological control agents elevate hantavirus by subsidizing deer mouse populations

    Science.gov (United States)

    Dean E. Pearson; Ragan M. Callaway

    2006-01-01

    Biological control of exotic invasive plants using exotic insects is practiced under the assumption that biological control agents are safe if they do not directly attack non-target species. We tested this assumption by evaluating the potential for two host-specific biological control agents (Urophora spp.), widely established in North America for spotted...

  7. Bacterial colonization of the ovarian bursa in dogs with clinically suspected pyometra and in controls.

    Science.gov (United States)

    Rubio, Alejandro; Boyen, Filip; Tas, Olaf; Kitshoff, Adriaan; Polis, Ingeborgh; Van Goethem, Bart; de Rooster, Hilde

    2014-10-15

    Septic peritonitis occurs relatively commonly in dogs. Secondary septic peritonitis is usually associated with perforation of intestines or infected viscera, such as the uterus in pyometra cases. The aim of this study was to evaluate the bacterial flora in the ovarian bursae of intact bitches as a potential source of contamination. One hundred forty dogs, clinically suspected of pyometra, were prospectively enrolled. The control group consisted of 26 dogs that underwent elective ovariohysterectomies and 18 dogs with mammary gland tumors that were neutered at the time of mastectomy. Bacteriology samples were taken aseptically at the time of surgery from the bursae and the uterus in all dogs. Twenty-two dogs that were clinically suspected of pyometra had sterile uterine content ("mucometra" cases); the remaining 118 had positive uterine cultures ("pyometra" cases) and septic peritoneal fluid was present in 10% of these cases. Of the 118 pyometra cases, 9 had unilateral and 15 had bilateral bacterial colonization of their ovarian bursae. However, the bacteria from the ovarian bursa were similar to those recovered from the uterine pus in only half of the cases. Furthermore, positive bursae were also seen in one mucometra dog (unilateral) and in four control dogs (two unilateral and two bilateral). The data illustrate that the canine ovarian bursa can harbor bacteria. The biological importance of these isolations remains unclear. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Fed-Batch Production of Bacterial Ghosts Using Dielectric Spectroscopy for Dynamic Process Control

    Directory of Open Access Journals (Sweden)

    Andrea Meitz

    2016-03-01

    Full Text Available The Bacterial Ghost (BG platform technology evolved from a microbiological expression system incorporating the ϕX174 lysis gene E. E-lysis generates empty but structurally intact cell envelopes (BGs from Gram-negative bacteria which have been suggested as candidate vaccines, immunotherapeutic agents or drug delivery vehicles. E-lysis is a highly dynamic and complex biological process that puts exceptional demands towards process understanding and control. The development of a both economic and robust fed-batch production process for BGs required a toolset capable of dealing with rapidly changing concentrations of viable biomass during the E-lysis phase. This challenge was addressed using a transfer function combining dielectric spectroscopy and soft-sensor based biomass estimation for monitoring the rapid decline of viable biomass during the E-lysis phase. The transfer function was implemented to a feed-controller, which followed the permittivity signal closely and was capable of maintaining a constant specific substrate uptake rate during lysis phase. With the described toolset, we were able to increase the yield of BG production processes by a factor of 8–10 when compared to currently used batch procedures reaching lysis efficiencies >98%. This provides elevated potentials for commercial application of the Bacterial Ghost platform technology.

  9. BIOMASS PRODUCTION AND FORMULATION OF Bacillus subtilis FOR BIOLOGICAL CONTROL

    Directory of Open Access Journals (Sweden)

    Amran Muis

    2016-10-01

    Full Text Available Bacillus subtilis is a widespread bacterium found in soil, water, and air. It controls the growth of certain harmful bacteria and fungi, presumably by competing for nutrients, growth sites on plants, and by directly colonizing and attaching to fungal pathogens. When applied to seeds, it colonizes the developing root system of the plants and continues to live on the root system and provides protection throughout the growing season. The study on biomass production and formulation of B. subtilis for biological control was conducted in the laboratory of Department of Plant Pathology, College of Agriculture, University of the Philippines Los Baños (UPLB-CA, College, Laguna from May to July 2005. The objective of the study was to determine the optimum pH and a good carbon source for biomass production of B. subtilis and to develop a seed treatment formulation of B. subtilis as biological control agent. Results showed that the optimum pH for growth of B. subtilis was pH 6 (1.85 x 109 cfu/ml. In laboratory tests for biomass production using cassava flour, corn flour, rice flour, and brown sugar as carbon sources, it grew best in brown sugar plus yeast extract medium (6.8 x 108 cfu ml-1 in sterile distilled water and 7.8 x 108 cfu ml-1 in coconut water. In test for bacterial biomass carriers, talc proved to be the best in terms of number of bacteria recovered from the seeds (3.98 x 105 cfu seed-1.

  10. Development of bacterial communities in biological soil crusts along a revegetation chronosequence in the Tengger Desert, northwest China

    Science.gov (United States)

    Liu, Lichao; Liu, Yubing; Zhang, Peng; Song, Guang; Hui, Rong; Wang, Zengru; Wang, Jin

    2017-08-01

    Knowledge of structure and function of microbial communities in different successional stages of biological soil crusts (BSCs) is still scarce for desert areas. In this study, Illumina MiSeq sequencing was used to assess the compositional changes of bacterial communities in different ages of BSCs in the revegetation of Shapotou in the Tengger Desert. The most dominant phyla of bacterial communities shifted with the changed types of BSCs in the successional stages, from Firmicutes in mobile sand and physical crusts to Actinobacteria and Proteobacteria in BSCs, and the most dominant genera shifted from Bacillus, Enterococcus and Lactococcus to RB41_norank and JG34-KF-361_norank. Alpha diversity and quantitative real-time polymerase chain reaction (PCR) analysis indicated that bacterial richness and abundance reached their highest levels after 15 years of BSC development. Redundancy analysis showed that silt + clay content and total K were the prime determinants of the bacterial communities of BSCs. The results suggested that bacterial communities of BSCs recovered quickly with the improved soil physicochemical properties in the early stages of BSC succession. Changes in the bacterial community structure may be an important indicator in the biogeochemical cycling and nutrient storage in early successional stages of BSCs in desert ecosystems.

  11. Regulatory cascade and biological activity of Beauveria bassiana oosporein that limits bacterial growth after host death.

    Science.gov (United States)

    Fan, Yanhua; Liu, Xi; Keyhani, Nemat O; Tang, Guirong; Pei, Yan; Zhang, Wenwen; Tong, Sheng

    2017-02-28

    The regulatory network and biological functions of the fungal secondary metabolite oosporein have remained obscure. Beauveria bassiana has evolved the ability to parasitize insects and outcompete microbial challengers for assimilation of host nutrients. A novel zinc finger transcription factor, BbSmr1 ( B. bassiana secondary metabolite regulator 1), was identified in a screen for oosporein overproduction. Deletion of Bbsmr1 resulted in up-regulation of the oosporein biosynthetic gene cluster ( OpS genes) and constitutive oosporein production. Oosporein production was abolished in double mutants of Bbsmr1 and a second transcription factor, OpS3 , within the oosporein gene cluster ( ΔBbsmr1ΔOpS3 ), indicating that BbSmr1 acts as a negative regulator of OpS3 expression. Real-time quantitative PCR and a GFP promoter fusion construct of OpS1 , the oosporein polyketide synthase, indicated that OpS1 is expressed mainly in insect cadavers at 24-48 h after death. Bacterial colony analysis in B. bassiana -infected insect hosts revealed increasing counts until host death, with a dramatic decrease (∼90%) after death that correlated with oosporein production. In vitro studies verified the inhibitory activity of oosporein against bacteria derived from insect cadavers. These results suggest that oosporein acts as an antimicrobial compound to limit microbial competition on B. bassiana -killed hosts, allowing the fungus to maximally use host nutrients to grow and sporulate on infected cadavers.

  12. Stability and effectiveness against bacterial adhesion of poly(ethylene oxide) coatings in biological fluids.

    Science.gov (United States)

    Roosjen, Astrid; de Vries, Joop; van der Mei, Henny C; Norde, Willem; Busscher, Henk J

    2005-05-01

    Poly(ethylene oxide) (PEO) coatings have been shown to reduce the adhesion of different microbial strains and species and thus are promising as coatings to prevent biomaterial-centered infection of medical implants. Clinically, however, PEO coatings are not yet applied, as little is known about their stability and effectiveness in biological fluids. In this study, PEO coatings coupled to a glass substratum through silyl ether bonds were exposed for different time intervals to saliva, urine, or phosphate-buffered saline (PBS) as a reference at 37 degrees C. After exposure, the effectiveness of the coatings against bacterial adhesion was assessed in a parallel plate flow chamber. The coatings appeared effective against Staphylococcus epidermidis adhesion for 24, 48, and 0.5 h in PBS, urine, and saliva, respectively. Using XPS and contact-angle measurements, the variations in effectiveness could be attributed to conditioning film formation. The overall short stability results from hydrolysis of the coupling of the PEO chains to the substratum. (c) 2005 Wiley Periodicals, Inc.

  13. Utilization of chitinolytic bacterial isolates to control anthracnose of ...

    African Journals Online (AJOL)

    SAM

    2014-04-09

    Apr 9, 2014 ... Assay of antagonistic bacterial chitinolytic to C. gloeosporioides was ... 1632 Afr. J. Biotechnol. ... microorganisms, by their interactions with various plant ... ristics such as colony, mycelia as well as shape and size of conidia.

  14. The potential of endomycorrhizal fungi in controlling tomato bacterial ...

    African Journals Online (AJOL)

    user

    2012-08-21

    Aug 21, 2012 ... The impact of colonization by three mycorrhizal fungi on tomato bacterial wilt caused by Ralstonia ... Three species of arbuscular mycorrhizal fungal (AMF) were tested. (Glomus ...... management of fruits and vegetables. Vol.

  15. Bacterial flora of spices and its control by gamma irradiation

    International Nuclear Information System (INIS)

    El-Zawahry, Y.A.; Youssef, Y.A.; Awny, N.M.; Hussein, H.A.

    1985-01-01

    The bacterial contamination was tested in 26 samples of spices. Chili, allspice and paprika were the most contaminated spices by bacteria. Five bacterial genera were isolated, namely bacillus, staphylococcus, streptococcus, micrococcus, and coccobacillus, all being gram-positive. Most isolates have been related to the genus bacillus. The bacterial isolates were identified as B. alvei, B. circulans, B. megaterium, B. pasteurii, B. pumilus, B. thuringiensis, B. sphaericus, B. incertaesedis, Micrococcus luteus, staphylococcus aureus, streptococcus sp. and coccobacillus sp. Irradiation of spices led to a significant decrease in the bacterial count of all samples. The dose required to inhibit completely the natural bacterial flora was 25 KGY. The most radioresistant isolates were staphylococcus aureus and micrococcus luteus which were subjected to sublethal doses of 15 and 20 KGY respectively. The dose response curves of the 2 most radioresistant isolates showed simple exponential relationship. The D 10-value of S. aureus and M. luteus were 0.9 and 1.1 KGY, respectively. The effect of storage period on the bacterial load of, as well as, the antibacterial activity of the tested spices were investigated. (author)

  16. Bacterial flora of spices and its control by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    El-Zawahry, Y A; Youssef, Y A; Awny, N M; Hussein, H A

    1985-01-01

    The bacterial contamination was tested in 26 samples of spices. Chili, allspice and paprika were the most contaminated spices by bacteria. Five bacterial genera were isolated, namely bacillus, staphylococcus, streptococcus, micrococcus, and coccobacillus, all being gram-positive. Most isolates have been related to the genus bacillus. The bacterial isolates were identified as B. alvei, B. circulans, B. megaterium, B. pasteurii, B. pumilus, B. thuringiensis, B. sphaericus, B. incertaesedis, Micrococcus luteus, staphylococcus aureus, streptococcus sp. and coccobacillus sp. Irradiation of spices led to a significant decrease in the bacterial count of all samples. The dose required to inhibit completely the natural bacterial flora was 25 KGY. The most radioresistant isolates were staphylococcus aureus and micrococcus luteus which were subjected to sublethal doses of 15 and 20 KGY respectively. The dose response curves of the 2 most radioresistant isolates showed simple exponential relationship. The D 10-value of S. aureus and M. luteus were 0.9 and 1.1 KGY, respectively. The effect of storage period on the bacterial load of, as well as, the antibacterial activity of the tested spices were investigated.

  17. Clavanin bacterial sepsis control using a novel methacrylate nanocarrier

    Directory of Open Access Journals (Sweden)

    Saúde ACM

    2014-10-01

    Full Text Available Amanda CM Saúde,1 Alicia S Ombredane,1 Osmar N Silva,1 João ARG Barbosa,1,2 Susana E Moreno,3 Ana Claudia Guerra Araujo,4 Rosana Falcão,4 Luciano P Silva,4 Simoni C Dias,1 Octávio L Franco1,3 1Programa de Pós Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, FD, Brazil; 2Laboratório de Biofísica-Departamento de Biologia Celular-IB, Universidade de Brasília – UNB, DF, Brazil; 3Universidade Católica Dom Bosco – UCDB, Campo Grande, MS, Brazil; 4Empresa Brasileira de Pesquisa Agropecuária – EMBRAPA – Recursos Genéticos e Biotecnologia, Brasília, DF, Brazil Abstract: Controlling human pathogenic bacteria is a worldwide problem due to increasing bacterial resistance. This has prompted a number of studies investigating peptides isolated from marine animals as a possible alternative for control of human pathogen infections. Clavanins are antimicrobial peptides isolated from the marine tunicate Styela clava, showing 23 amino acid residues in length, cationic properties, and also high bactericidal activity. In spite of clear benefits from the use of peptides, currently 95% of peptide properties have limited pharmaceutical applicability, such as low solubility and short half-life in the circulatory system. Here, nanobiotechnology was used to encapsulate clavanin A in order to develop nanoantibiotics against bacterial sepsis. Clavanin was nanostructured using EUDRAGIT® L 100-55 and RS 30 D solution (3:1 w:w. Atomic force, scanning electron microscopy and dynamic light scattering showed nanoparticles ranging from 120 to 372 nm in diameter, with a zeta potential of -7.16 mV and a polydispersity index of 0.123. Encapsulation rate of 98% was assessed by reversed-phase chromatography. In vitro bioassays showed that the nanostructured clavanin was partially able to control development of Staphylococcus aureus, Klebsiella pneumoniae, and

  18. An Overview of the Control of Bacterial Pathogens in Cattle Manure

    Directory of Open Access Journals (Sweden)

    Christy E. Manyi-Loh

    2016-08-01

    Full Text Available Cattle manure harbors microbial constituents that make it a potential source of pollution in the environment and infections in humans. Knowledge of, and microbial assessment of, manure is crucial in a bid to prevent public health and environmental hazards through the development of better management practices and policies that should govern manure handling. Physical, chemical and biological methods to reduce pathogen population in manure do exist, but are faced with challenges such as cost, odor pollution, green house gas emission, etc. Consequently, anaerobic digestion of animal manure is currently one of the most widely used treatment method that can help to salvage the above-mentioned adverse effects and in addition, produces biogas that can serve as an alternative/complementary source of energy. However, this method has to be monitored closely as it could be fraught with challenges during operation, caused by the inherent characteristics of the manure. In addition, to further reduce bacterial pathogens to a significant level, anaerobic digestion can be combined with other methods such as thermal, aerobic and physical methods. In this paper, we review the bacterial composition of cattle manure as well as methods engaged in the control of pathogenic microbes present in manure and recommendations that need to be respected and implemented in order to prevent microbial contamination of the environment, animals and humans.

  19. Impact of climate change on filarial vector, Culex quinquefasciatus and control using bacterial pesticide, spinosad

    Directory of Open Access Journals (Sweden)

    Nareshkumar Arjunan

    2014-02-01

    Full Text Available Objective: To show the effect of temperature on the biology of Culex quinquefasciatus and also to show the effect of the bacterial pesticide, spinosad on developmental stages of the filarial vector. Methods: A laboratory colony of mosquito larvae was used for the larvicidal activity of temperature and spinosad. Twenty-five numbers of first, second, third, fourth instar larvae were introduced into the 500 mL glass beaker containing 250 mL of de-chlorinated water with desired temperatures (16 °C, 20 °C, 24 °C, 28 °C, 32 °C, 36 °C, similarly spinosad, at different concentrations. The development was observed for every 24 h. Results: The results showed that the rise in temperature acts as a growth inhibiting factor for mosquitoes. And no development was found in the temperature below 16 °C and above 36 °C. The hatchability was increased as the temperature was increased up to 32 °C, after which eclosion rates dropped gradually. Conclusions: 32 °C was obtained as the maximum sustainable temperature and after which the developmental rate was gradually reduced. The optimal temperature for development was lower than the temperatures at which development was quickest. The bacterial pesticide spinosad showed that it is an effective mosquito control agent and can be used for further integrated pest management programmes.

  20. BIOLOGICAL CONTROL OF WEEDS BY MEANS OF PLANT PATHOGENS

    Directory of Open Access Journals (Sweden)

    Marija Ravlić

    2014-06-01

    Full Text Available Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, conservation and augmentative (inoculative and inundated biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chemical herbicides are not allowed, if resistant weed species are present or in the integrated pest management against weeds with reduced herbicides doses and other non-chemical measures, but it has certain limitations and disadvantages.

  1. Effects of chemical and biological pesticides on plant growth parameters and rhizospheric bacterial community structure in Vigna radiata

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sunil; Gupta, Rashi; Sharma, Shilpi, E-mail: shilpi@dbeb.iitd.ac.in

    2015-06-30

    Highlights: • Non-target effects of pesticides employing qualitative and quantitative approaches. • Qualitative shifts in resident and active bacterial community structure. • Abundance of 16S rRNA gene and transcripts were reduced significantly. • Effects of biological pesticide similar to chemical pesticides on rhizospheric bacteria. - Abstract: With increasing application of pesticides in agriculture, their non-target effects on soil microbial communities are critical to soil health maintenance. The present study aimed to evaluate the effects of chemical pesticides (chlorpyrifos and cypermethrin) and a biological pesticide (azadirachtin) on growth parameters and the rhizospheric bacterial community of Vigna radiata. Qualitative and quantitative analysis by PCR-denaturing gradient gel electrophoresis (DGGE) and q-PCR, respectively, of the 16S rRNA gene and transcript were performed to study the impact of these pesticides on the resident and active rhizospheric bacterial community. While plant parameters were not affected significantly by the pesticides, a shift in the bacterial community structure was observed with an adverse effect on the abundance of 16S rRNA gene and transcripts. Chlorpyrifos showed almost complete degradation toward the end of the experiment. These non-target impacts on soil ecosystems and the fact that the effects of the biopesticide mimic those of chemical pesticides raise serious concerns regarding their application in agriculture.

  2. Effects of chemical and biological pesticides on plant growth parameters and rhizospheric bacterial community structure in Vigna radiata

    International Nuclear Information System (INIS)

    Singh, Sunil; Gupta, Rashi; Sharma, Shilpi

    2015-01-01

    Highlights: • Non-target effects of pesticides employing qualitative and quantitative approaches. • Qualitative shifts in resident and active bacterial community structure. • Abundance of 16S rRNA gene and transcripts were reduced significantly. • Effects of biological pesticide similar to chemical pesticides on rhizospheric bacteria. - Abstract: With increasing application of pesticides in agriculture, their non-target effects on soil microbial communities are critical to soil health maintenance. The present study aimed to evaluate the effects of chemical pesticides (chlorpyrifos and cypermethrin) and a biological pesticide (azadirachtin) on growth parameters and the rhizospheric bacterial community of Vigna radiata. Qualitative and quantitative analysis by PCR-denaturing gradient gel electrophoresis (DGGE) and q-PCR, respectively, of the 16S rRNA gene and transcript were performed to study the impact of these pesticides on the resident and active rhizospheric bacterial community. While plant parameters were not affected significantly by the pesticides, a shift in the bacterial community structure was observed with an adverse effect on the abundance of 16S rRNA gene and transcripts. Chlorpyrifos showed almost complete degradation toward the end of the experiment. These non-target impacts on soil ecosystems and the fact that the effects of the biopesticide mimic those of chemical pesticides raise serious concerns regarding their application in agriculture

  3. Assessment of temporal and spatial evolution of bacterial communities in a biological sand filter mesocosm treating winery wastewater.

    Science.gov (United States)

    Ramond, J-B; Welz, P J; Tuffin, M I; Burton, S G; Cowan, D A

    2013-07-01

    To assess the impact of winery wastewater (WW) on biological sand filter (BSF) bacterial community structures, and to evaluate whether BSFs can constitute alternative and valuable treatment- processes to remediate WW. During 112 days, WW was used to contaminate a BSF mesocosm (length 173 cm/width 106 cm/depth 30 cm). The effect of WW on bacterial communities of four BSF microenvironments (surface/deep, inlet/outlet) was investigated using terminal-restriction fragment length polymorphism (T-RFLP). BSF achieved high Na (95·1%), complete Cl and almost complete chemical oxygen demand (COD) (98·0%) and phenolic (99·2%) removals. T-RFLP analysis combined with anosim revealed that WW significantly modified the surface and deep BSF bacterial communities. BSF provided high COD, phenolic and salt removals throughout the experiment. WW-selected bacterial communities were thus able to tolerate and/or degrade WW, suggesting that community composition does not alter BSF performances. However, biomass increased significantly in the WW-impacted surface sediments, which could later lead to system clogging and should thus be monitored. BSFs constitute alternatives to constructed wetlands to treat agri effluents such as WW. To our knowledge, this study is the first unravelling the responses of BSF bacterial communities to contamination and suggests that WW-selected BSF communities maintained high removal performances. Journal of Applied Microbiology © 2013 The Society for Applied Microbiology.

  4. Bacterial diversity and community along the succession of biological soil crusts in the Gurbantunggut Desert, Northern China.

    Science.gov (United States)

    Zhang, Bingchang; Kong, Weidong; Wu, Nan; Zhang, Yuanming

    2016-06-01

    Biological soil crusts (BSCs) are common and play critical roles in semi-arid and arid ecosystems. Bacteria, as an important community in BSCs, play critical roles in biochemical processes. However, how bacterial diversity and community change in different successional stages of BSCs is still unknown. We used 454 pyrosequencing of 16S rRNA to investigate the bacterial composition and community, and the relationships between bacterial composition and environmental factors were also explored. In different successional stages of BSCs, the number of bacteria operational taxonomic units (OTUs) detected in each sample ranged from 2572 to 3157. Proteobacteria, Cyanobacteria, Bacteroidetes were dominant in BSCs, followed by Firmicutes, Acidobacteria, and Actinobacteria. At the successional stages of BSCs, bacterial communities, OTU composition and their relative abundance notably differentiated, and Cyanobacteria, especially Microcoleus vaginatus, dominated algal crust and lichen crust, and were the main C-fixing bacteria in BSCs. Proteobacteria and Bacteroidetes increased with the development of BSCs. OTUs related to Planomicrobium Chinese, Desulfobulbus sp., Desulfomicrobium sp., Arthrobacter sp., and Ahhaerbacter sp. showed higher relative abundance in bare sand than other successional stages of BSCs, while relative abundance of Sphingomonas sp. Niastella sp., Pedobacter, Candidatus solobacter, and Streptophyta increased with the development of BSCs. In successional stages of BSCs, bacterial OTUs composition demonstrated strong correlations with soil nutrients, soil salts, and soil enzymes. Additionally, variation of bacterial composition led to different ecological function. In bare sand, some species were related with mineral metabolism or promoting plant growth, and in algal crust and lichen crust, C-fixing bacteria increased and accumulated C to the desert soil. In later developed stage of BSCs, bacteria related with decomposition of organic matter, such as

  5. Configuration of biological wastewater treatment line and influent composition as the main factors driving bacterial community structure of activated sludge

    OpenAIRE

    Jaranowska, Paulina; Cydzik-Kwiatkowska, Agnieszka; Zieli?ska, Magdalena

    2013-01-01

    The structure of microbial consortia in wastewater treatment facilities is a resultant of environmental conditions created by the operational parameters of the purification process. In the research, activated sludge from nine Polish wastewater treatment plants (WWTPs) was investigated at a molecular level to determine the impact of the complexity of biological treatment line and the influent composition on the species structure and the diversity of bacterial consortia. The community fingerpri...

  6. Using metagenomics and metatranscriptomics to study specific bacterial species involved in biological phosphorus removal from wastewater

    DEFF Research Database (Denmark)

    Albertsen, Mads; McIlroy, Simon Jon; Stokholm-Bjerregaard, Mikkel

    an enrichment of the target organisms in laboratory scale reactors under controlled conditions. We demonstrate that it is now easy and affordable to extract genomes of all the dominant organisms from reactors due to reduced micro-diversity and further use these to examine their individual gene expression...... profiles by metatranscriptomics. To demonstrate this we revisited the bacteria involved in enhanced biological phosphorus removal (EBPR) from wastewater treatment plants. The EBPR process is used all over the world, has a large body of information regarding the underlying microbiology, and is often studied...

  7. Complexity, Analysis and Control of Singular Biological Systems

    CERN Document Server

    Zhang, Qingling; Zhang, Xue

    2012-01-01

    Complexity, Analysis and Control of Singular Biological Systems follows the control of real-world biological systems at both ecological and phyisological levels concentrating on the application of now-extensively-investigated singular system theory. Much effort has recently been dedicated to the modelling and analysis of developing bioeconomic systems and the text establishes singular examples of these, showing how proper control can help to maintain sustainable economic development of biological resources. The book begins from the essentials of singular systems theory and bifurcations before tackling  the use of various forms of control in singular biological systems using examples including predator-prey relationships and viral vaccination and quarantine control. Researchers and graduate students studying the control of complex biological systems are shown how a variety of methods can be brought to bear and practitioners working with the economics of biological systems and their control will also find the ...

  8. Bacterial Communities in Polluted Seabed Sediments: A Molecular Biology Assay in Leghorn Harbor

    Directory of Open Access Journals (Sweden)

    Carolina Chiellini

    2013-01-01

    Full Text Available Seabed sediments of commercial ports are often characterized by high pollution levels. Differences in number and distribution of bacteria in such areas can be related to distribution of pollutants in the port and to sediment conditions. In this study, the bacterial communities of five sites from Leghorn Harbor seabed were characterized, and the main bacterial groups were identified. T-RFLP was used for all samples; two 16S rRNA libraries and in silico digestion of clones were used to identify fingerprint profiles. Library data, phylogenetic analysis, and T-RFLP coupled with in silico digestion of the obtained sequences evidenced the dominance of Proteobacteria and the high percentage of Bacteroidetes in all sites. The approach highlighted similar bacterial communities between samples coming from the five sites, suggesting a modest differentiation among bacterial communities of different harbor seabed sediments and hence the capacity of bacterial communities to adapt to different levels and types of pollution.

  9. Maternal feeding controls fetal biological clock.

    Directory of Open Access Journals (Sweden)

    Hidenobu Ohta

    Full Text Available BACKGROUND: It is widely accepted that circadian physiological rhythms of the fetus are affected by oscillators in the maternal brain that are coupled to the environmental light-dark (LD cycle. METHODOLOGY/PRINCIPAL FINDINGS: To study the link between fetal and maternal biological clocks, we investigated the effects of cycles of maternal food availability on the rhythms of Per1 gene expression in the fetal suprachiasmatic nucleus (SCN and liver using a transgenic rat model whose tissues express luciferase in vitro. Although the maternal SCN remained phase-locked to the LD cycle, maternal restricted feeding phase-advanced the fetal SCN and liver by 5 and 7 hours respectively within the 22-day pregnancy. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that maternal feeding entrains the fetal SCN and liver independently of both the maternal SCN and the LD cycle. This indicates that maternal-feeding signals can be more influential for the fetal SCN and particular organ oscillators than hormonal signals controlled by the maternal SCN, suggesting the importance of a regular maternal feeding schedule for appropriate fetal molecular clockwork during pregnancy.

  10. Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

    Directory of Open Access Journals (Sweden)

    Jiyeong Park

    2014-09-01

    Full Text Available We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN Meloidogyne hapla in carrot (Daucus carota subsp. sativus and tomato (Solanum lycopersicum. Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

  11. Effect of Organic and Biological Fertilizers on Growth and Yield of Tomatoes (Lycopersicon esculentum Mill. and Bacterial Colonization

    Directory of Open Access Journals (Sweden)

    H. Makarian

    2016-02-01

    Full Text Available Introduction: In recent decades, excessive use of chemical fertilizers causes environmental problems such as water resource pollution and decrease in soil fertility. Organic matters are excellent sources of plant-available nutrients and their addition to soil could maintain high microbial populations and activities. In crop studies, Prabha et al. (2007 reported that there was excellent plant growth as well as yield in garlic plants that received vermicompost as nutrient in the field (28. Recent studies confirmed that, a number of bacterial species mostly associated with the plant rhizosphere, are found to be beneficial for plant growth, yield and crop quality. Therefore, the objective of this study is to investigate the growth promoting effects of organic and bio-fertilizers on tomato growth and yield. Materials and Methods: A factorial experiment in randomized complete block design with three replications was conducted at the College of Agricultural, University of Shahrood in 2011. Geographically, the site is located in Bastam (36° 25’E, 54° 58’N, 1349 m a.s.l..The climate of this region is semi-arid. Treatments included three levels of organic fertilizers: vermicompost (1300 kgha-1, cow manure (3350 kgha-1, and control, biological fertilizer in four levels (Pseudomonas putyda, Pseudomonas fluorescens, Azotobacter chrococcum and control. The bacterial suspension for each species was applied at a rate of 3 liters per hectare. Metribuzin herbicide (wettable 80% powder was used at a rate of 1000 gr. ha-1. Petopride No. 2' variety of tomato (Lycopersicon esculentum Mill. was used in the present experiment. At the time of harvesting, the plant characteristics namely lengths and diameter of stem, number and weight of fruit, weight of stem and leaf were also registered. Statistical analyses of data were performed with statistical software Mstatc. Significant differences between means refer to the probability level of 0.05 by LSD test. Results

  12. The potential of endomycorrhizal fungi in controlling tomato bacterial ...

    African Journals Online (AJOL)

    The impact of colonization by three mycorrhizal fungi on tomato bacterial wilt caused by Ralstonia solanaceraum was investigated. Three species of arbuscular mycorrhizal fungal (AMF) were tested (Glomus mosseae, Scutellospora sp. and Gigaspora margarita). Siginificant differences in tomato growth based on plant ...

  13. Will the Convention on Biological Diversity put an end to biological control?

    NARCIS (Netherlands)

    Lenteren, van J.C.; Cock, M.J.W.; Brodeur, J.; Barratt, B.I.P.; Bigler, F.; Bolckmans, K.; Haas, F.; Mason, P.G.; Parra, J.R.P.

    2011-01-01

    Will the Convention on Biological Diversity put an end to biological control? Under the Convention on Biological Diversity countries have sovereign rights over their genetic resources. Agreements governing the access to these resources and the sharing of the benefits arising from their use need to

  14. Effectiveness of a biological control agent Palexorista gilvoides in ...

    African Journals Online (AJOL)

    ACSS

    Effectiveness of a biological control agent Palexorista gilvoides in controlling Gonometa podorcarpi in conifer ... gilvoides as a potential biological control agent for G. podocarpi. Field and laboratory studies further established that P. .... version for windows (SPSS, 2002). Results. Gonometa podocarpi was present in.

  15. Status of biological control in vegetation management in forestry

    Science.gov (United States)

    George P. Markin; Donald E. Gardner

    1993-01-01

    Biological control traditionally depends upon importing the natural enemies of introduced weeds. Since vegetation management in forestry has primarily been aimed at protecting economic species of trees from competition from other native plants, biological control has been of little use in forestry. An alternative approach to controlling unwanted native plants,...

  16. Biological activity of some bacterial isolates against soil borne pathogenic fungi

    International Nuclear Information System (INIS)

    Makbol, H.; Refae, R.I.; Eid, H.A.; Mohamed, O.M.

    2011-01-01

    The antagonistic activity of three bacterial isolates namely Micro bacterium terregens, Cellulosimicrobium cellulans and Bacillus amyloliquefaciens was evaluated through direct confrontation method and filtrates culture against the growth of Fusarium solani, Fusarium oxysporum, Rhizoctonia solani and Phytophthra cactorum. All bacterial isolates showed the inhibition of the mycelia growth of the isolated fungi as resulting to confrontation methods except R. solani with C. cellulans that showed no inhibitory effect and energized the low activity with B. amyloliquefaciens. Culture filtrate of different bacterial isolates after different incubation periods revealed that the highest antifungal activity between 3-10 days

  17. Systems biology of bacterial nitrogen fixation: High-throughput technology and its integrative description with constraint-based modeling

    Directory of Open Access Journals (Sweden)

    Resendis-Antonio Osbaldo

    2011-07-01

    Full Text Available Abstract Background Bacterial nitrogen fixation is the biological process by which atmospheric nitrogen is uptaken by bacteroids located in plant root nodules and converted into ammonium through the enzymatic activity of nitrogenase. In practice, this biological process serves as a natural form of fertilization and its optimization has significant implications in sustainable agricultural programs. Currently, the advent of high-throughput technology supplies with valuable data that contribute to understanding the metabolic activity during bacterial nitrogen fixation. This undertaking is not trivial, and the development of computational methods useful in accomplishing an integrative, descriptive and predictive framework is a crucial issue to decoding the principles that regulated the metabolic activity of this biological process. Results In this work we present a systems biology description of the metabolic activity in bacterial nitrogen fixation. This was accomplished by an integrative analysis involving high-throughput data and constraint-based modeling to characterize the metabolic activity in Rhizobium etli bacteroids located at the root nodules of Phaseolus vulgaris (bean plant. Proteome and transcriptome technologies led us to identify 415 proteins and 689 up-regulated genes that orchestrate this biological process. Taking into account these data, we: 1 extended the metabolic reconstruction reported for R. etli; 2 simulated the metabolic activity during symbiotic nitrogen fixation; and 3 evaluated the in silico results in terms of bacteria phenotype. Notably, constraint-based modeling simulated nitrogen fixation activity in such a way that 76.83% of the enzymes and 69.48% of the genes were experimentally justified. Finally, to further assess the predictive scope of the computational model, gene deletion analysis was carried out on nine metabolic enzymes. Our model concluded that an altered metabolic activity on these enzymes induced

  18. Application and Development of Biological AFM for the Study of Bacterial Toxins

    National Research Council Canada - National Science Library

    Yang, Jie

    1999-01-01

    ... with other conventional methods. These studies have also established a solid foundation for our structural elucidation of molecular level conformation of membranous bacterial toxins, such as cholera toxin and alpha-hemolysin...

  19. Nanostructured coatings for controlling bacterial biofilms and antibiotic resistance

    OpenAIRE

    Ivanova, Kristina Dimitrova

    2017-01-01

    The accelerated emergence of drug resistant bacteria is one of the most serious problems in healthcare and the difficulties in finding new antibiotics make it even more challenging. To overcome the action of antibiotics bacteria develop effective resistance mechanisms including the formation of biofilms. Biofilms are bacterial communities of cells embedded in a self-produced polymeric matrix commonly found on medical devices such as indwelling catheters. When pathogens adopt this mode of grow...

  20. Synergistic and additive effect of oregano essential oil and biological silver nanoparticles against multidrug-resistant bacterial strains

    Directory of Open Access Journals (Sweden)

    Sara eScandorieiro

    2016-05-01

    Full Text Available Bacterial resistance to conventional antibiotics has become a clinical and public health problem, making therapeutic decisions more challenging. Plant compounds and nanodrugs have been proposed as potential antimicrobial alternatives. Studies have shown that oregano (Origanum vulgare essential oil (OEO and silver nanoparticles have potent antibacterial activity, also against multidrug-resistant strains; however, the strong organoleptic characteristics of OEO and the development of resistance to these metal nanoparticles can limit their use. This study evaluated the antibacterial effect of a two-drug combination of biologically synthesized silver nanoparticles (bio-AgNP, produced by Fusarium oxysporum, and OEO against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. OEO and bio-AgNP showed bactericidal effects against all seventeen strains tested, with minimal inhibitory concentrations (MIC ranging from 0.298 to 1.193 mg/mL and 62.5 to 250 µM, respectively. Time-kill curves indicated that OEO acted rapidly (within 10 min, while the metallic nanoparticles took 4 h to kill Gram-negative bacteria and 24 h to kill Gram-positive bacteria. The combination of the two compounds resulted in a synergistic or additive effect, reducing their MIC values and reducing the time of action compared to bio-AgNP used alone, i.e., 20 min for Gram-negative bacteria and 7 h for Gram-positive bacteria. Scanning electron microscopy (SEM revealed similar morphological alterations in Staphylococcus aureus (non-methicillin-resistant S. aureus, non-MRSA cells exposed to three different treatments (OEO, bio-AgNP and combination of the two, which appeared cell surface blebbing. Individual and combined treatments showed reduction in cell density and decrease in exopolysaccharide matrix compared to untreated bacterial cells. It indicated that this composition have an antimicrobial activity against S. aureus by disrupting cells. Both compounds

  1. Synergistic and Additive Effect of Oregano Essential Oil and Biological Silver Nanoparticles against Multidrug-Resistant Bacterial Strains.

    Science.gov (United States)

    Scandorieiro, Sara; de Camargo, Larissa C; Lancheros, Cesar A C; Yamada-Ogatta, Sueli F; Nakamura, Celso V; de Oliveira, Admilton G; Andrade, Célia G T J; Duran, Nelson; Nakazato, Gerson; Kobayashi, Renata K T

    2016-01-01

    Bacterial resistance to conventional antibiotics has become a clinical and public health problem, making therapeutic decisions more challenging. Plant compounds and nanodrugs have been proposed as potential antimicrobial alternatives. Studies have shown that oregano (Origanum vulgare) essential oil (OEO) and silver nanoparticles have potent antibacterial activity, also against multidrug-resistant strains; however, the strong organoleptic characteristics of OEO and the development of resistance to these metal nanoparticles can limit their use. This study evaluated the antibacterial effect of a two-drug combination of biologically synthesized silver nanoparticles (bio-AgNP), produced by Fusarium oxysporum, and OEO against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. OEO and bio-AgNP showed bactericidal effects against all 17 strains tested, with minimal inhibitory concentrations (MIC) ranging from 0.298 to 1.193 mg/mL and 62.5 to 250 μM, respectively. Time-kill curves indicated that OEO acted rapidly (within 10 min), while the metallic nanoparticles took 4 h to kill Gram-negative bacteria and 24 h to kill Gram-positive bacteria. The combination of the two compounds resulted in a synergistic or additive effect, reducing their MIC values and reducing the time of action compared to bio-AgNP used alone, i.e., 20 min for Gram-negative bacteria and 7 h for Gram-positive bacteria. Scanning electron microscopy (SEM) revealed similar morphological alterations in Staphylococcus aureus (non-methicillin-resistant S. aureus, non-MRSA) cells exposed to three different treatments (OEO, bio-AgNP and combination of the two), which appeared cell surface blebbing. Individual and combined treatments showed reduction in cell density and decrease in exopolysaccharide matrix compared to untreated bacterial cells. It indicated that this composition have an antimicrobial activity against S. aureus by disrupting cells. Both compounds showed very low

  2. Synthetic biology expands chemical control of microorganisms.

    Science.gov (United States)

    Ford, Tyler J; Silver, Pamela A

    2015-10-01

    The tools of synthetic biology allow researchers to change the ways engineered organisms respond to chemical stimuli. Decades of basic biology research and new efforts in computational protein and RNA design have led to the development of small molecule sensors that can be used to alter organism function. These new functions leap beyond the natural propensities of the engineered organisms. They can range from simple fluorescence or growth reporting to pathogen killing, and can involve metabolic coordination among multiple cells or organisms. Herein, we discuss how synthetic biology alters microorganisms' responses to chemical stimuli resulting in the development of microbes as toxicity sensors, disease treatments, and chemical factories. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Corn cob biochar increases soil culturable bacterial abundance without enhancing their capacities in utilizing carbon sources in Biolog Eco-plates

    Institute of Scientific and Technical Information of China (English)

    JIANG Lin-lin; HAN Guang-ming; LAN Yu; LIU Sai-nan; GAO Ji-ping; YANG Xu; MENG Jun; CHEN Wen-fu

    2017-01-01

    Biochar has been shown to influence soil microbial communities in terms of their abundance and diversity.However,the relationship among microbial abundance,structure and C metabolic traits is not well studied under biochar application.Here it was hypothesized that the addition of biochar with intrinsic properties (i.e.,porous structure) could affect the proliferation of culturable microbes and the genetic structure of soil bacterial communities.In the meantime,the presence of available organic carbon in biochar may influence the C utilization capacities of microbial community in Biolog Eco-plates.A pot experiment was conducted with differenct biochar application (BC) rates:control (0 t ha-1),BC1 (20 t ha-1) and BC2 (40 t ha-1).Culturable microorganisms were enumerated via the plate counting method.Bacterial diversity was examined using denaturing gradient gel electrophoresis (DGGE).Microbial capacity in using C sources was assessed using Biolog Eco-plates.The addition of biochar stimulated the growth of actinomyces and bacteria,especially the ammonifying bacteria and azotobacteria,but had no significant effect on fungi proliferation.The phylogenetic distribution of the operational taxonomic units could be divided into the following groups with the biochar addition:Firmicutes,Acidobacteria,Gemmatimonadetes,Actinobacteria,Cyanobacteria and α-,β-,γ-and δ-Proteobacteria (average similarity >95%).Biochar application had a higher capacity utilization for L-asparagine,Tween 80,D-mannitol,L-serine,γ-hydroxybutyric acid,N-acetyI-D-glucosamine,glycogen,itaconic acid,glycyl-L-glutamic acid,α-ketobutyricacid and putrescine,whereas it had received decreased capacities in using the other 20 carbon sources in Biolog Eco-plates.Redundancy analysis (RDA) revealed that the physico-chemical properties,indices of bacterial diversity,and C metabolic traits were positively correlated with the appearance of novel sequences under BC2 treatment.Our study indicates that the

  4. Biological control of the terrestrial carbon sink

    Science.gov (United States)

    Schulze, E.-D.

    2006-03-01

    This lecture reviews the past (since 1964 when the International Biological Program began) and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production) and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in plant growth has

  5. Biological control of the terrestrial carbon sink

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze

    2006-01-01

    Full Text Available This lecture reviews the past (since 1964 when the International Biological Program began and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in

  6. Understanding Federal regulations as guidelines for classical biological control programs

    Science.gov (United States)

    Michael E. Montgomery

    2011-01-01

    This chapter reviews the legislation and rules that provide the foundation for federal regulation of the introduction of natural enemies of insects as biological control agents. It also outlines the steps for complying with regulatory requirements, using biological control of Adelges tsugae Annand, the hemlock woolly adelgid (HWA), as an example. The...

  7. Efficiency of using green algae as biological controllers against toxic ...

    African Journals Online (AJOL)

    Efficiency of using green algae as biological controllers against toxic algal taxa in cultured ... of two green algal species as biological control of the growth of toxic blue-green algae. ... African Journal of Aquatic Science 2014, 39(4): 443–450 ...

  8. The Control of Chemical and Biological Weapons.

    Science.gov (United States)

    Alexander, Archibald S.; And Others

    This book is composed of four papers prepared to illuminate the problem areas which might arise if the policies of the 1925 Geneva Protocol and other measures to limit chemical and biological weapons are ratified by the United States Senate. The papers included are: Legal Aspects of the Geneva Protocol of 1925; The Use of Herbicides in War: A…

  9. Biological control of livestock pests: Pathogens

    Science.gov (United States)

    Interest in biological methods for livestock and poultry pest management is largely motivated by the development of resistance to most of the available synthetic pesticides by the major pests. There also has been a marked increase in organic systems, and those that promote animal welfare by reducing...

  10. Biological Control Strategies for Mosquito Vectors of Arboviruses.

    Science.gov (United States)

    Huang, Yan-Jang S; Higgs, Stephen; Vanlandingham, Dana L

    2017-02-10

    Historically, biological control utilizes predatory species and pathogenic microorganisms to reduce the population of mosquitoes as disease vectors. This is particularly important for the control of mosquito-borne arboviruses, which normally do not have specific antiviral therapies available. Although development of resistance is likely, the advantages of biological control are that the resources used are typically biodegradable and ecologically friendly. Over the past decade, the advancement of molecular biology has enabled optimization by the manipulation of genetic materials associated with biological control agents. Two significant advancements are the discovery of cytoplasmic incompatibility induced by Wolbachia bacteria, which has enhanced replacement programs, and the introduction of dominant lethal genes into local mosquito populations through the release of genetically modified mosquitoes. As various arboviruses continue to be significant public health threats, biological control strategies have evolved to be more diverse and become critical tools to reduce the disease burden of arboviruses.

  11. Biological Control Strategies for Mosquito Vectors of Arboviruses

    Directory of Open Access Journals (Sweden)

    Yan-Jang S. Huang

    2017-02-01

    Full Text Available Historically, biological control utilizes predatory species and pathogenic microorganisms to reduce the population of mosquitoes as disease vectors. This is particularly important for the control of mosquito-borne arboviruses, which normally do not have specific antiviral therapies available. Although development of resistance is likely, the advantages of biological control are that the resources used are typically biodegradable and ecologically friendly. Over the past decade, the advancement of molecular biology has enabled optimization by the manipulation of genetic materials associated with biological control agents. Two significant advancements are the discovery of cytoplasmic incompatibility induced by Wolbachia bacteria, which has enhanced replacement programs, and the introduction of dominant lethal genes into local mosquito populations through the release of genetically modified mosquitoes. As various arboviruses continue to be significant public health threats, biological control strategies have evolved to be more diverse and become critical tools to reduce the disease burden of arboviruses.

  12. Biology and control of Varroa destructor.

    Science.gov (United States)

    Rosenkranz, Peter; Aumeier, Pia; Ziegelmann, Bettina

    2010-01-01

    The ectoparasitic honey bee mite Varroa destructor was originally confined to the Eastern honey bee Apis cerana. After a shift to the new host Apis mellifera during the first half of the last century, the parasite dispersed world wide and is currently considered the major threat for apiculture. The damage caused by Varroosis is thought to be a crucial driver for the periodical colony losses in Europe and the USA and regular Varroa treatments are essential in these countries. Therefore, Varroa research not only deals with a fascinating host-parasite relationship but also has a responsibility to find sustainable solutions for the beekeeping. This review provides a survey of the current knowledge in the main fields of Varroa research including the biology of the mite, damage to the host, host tolerance, tolerance breeding and Varroa treatment. We first present a general view on the functional morphology and on the biology of the Varroa mite with special emphasis on host-parasite interactions during reproduction of the female mite. The pathology section describes host damage at the individual and colony level including the problem of transmission of secondary infections by the mite. Knowledge of both the biology and the pathology of Varroa mites is essential for understanding possible tolerance mechanisms in the honey bee host. We comment on the few examples of natural tolerance in A. mellifera and evaluate recent approaches to the selection of Varroa tolerant honey bees. Finally, an extensive listing and critical evaluation of chemical and biological methods of Varroa treatments is given. This compilation of present-day knowledge on Varroa honey bee interactions emphasizes that we are still far from a solution for Varroa infestation and that, therefore, further research on mite biology, tolerance breeding, and Varroa treatment is urgently needed. Copyright 2009 Elsevier Inc. All rights reserved.

  13. High bacterial diversity of biological soil crusts in water tracks over permafrost in the high arctic polar desert.

    Science.gov (United States)

    Steven, Blaire; Lionard, Marie; Kuske, Cheryl R; Vincent, Warwick F

    2013-01-01

    In this study we report the bacterial diversity of biological soil crusts (biocrusts) inhabiting polar desert soils at the northern land limit of the Arctic polar region (83° 05 N). Employing pyrosequencing of bacterial 16S rRNA genes this study demonstrated that these biocrusts harbor diverse bacterial communities, often as diverse as temperate latitude communities. The effect of wetting pulses on the composition of communities was also determined by collecting samples from soils outside and inside of permafrost water tracks, hill slope flow paths that drain permafrost-affected soils. The intermittent flow regime in the water tracks was correlated with altered relative abundance of phylum level taxonomic bins in the bacterial communities, but the alterations varied between individual sampling sites. Bacteria related to the Cyanobacteria and Acidobacteria demonstrated shifts in relative abundance based on their location either inside or outside of the water tracks. Among cyanobacterial sequences, the proportion of sequences belonging to the family Oscillatoriales consistently increased in relative abundance in the samples from inside the water tracks compared to those outside. Acidobacteria showed responses to wetting pulses in the water tracks, increasing in abundance at one site and decreasing at the other two sites. Subdivision 4 acidobacterial sequences tended to follow the trends in the total Acidobacteria relative abundance, suggesting these organisms were largely responsible for the changes observed in the Acidobacteria. Taken together, these data suggest that the bacterial communities of these high latitude polar biocrusts are diverse but do not show a consensus response to intermittent flow in water tracks over high Arctic permafrost.

  14. Biologically inspired rate control of chaos.

    Science.gov (United States)

    Olde Scheper, Tjeerd V

    2017-10-01

    The overall intention of chaotic control is to eliminate chaos and to force the system to become stable in the classical sense. In this paper, I demonstrate a more subtle method that does not eliminate all traces of chaotic behaviour; yet it consistently, and reliably, can provide control as intended. The Rate Control of Chaos (RCC) method is derived from metabolic control processes and has several remarkable properties. RCC can control complex systems continuously, and unsupervised, it can also maintain control across bifurcations, and in the presence of significant systemic noise. Specifically, I show that RCC can control a typical set of chaotic models, including the 3 and 4 dimensional chaotic Lorenz systems, in all modes. Furthermore, it is capable of controlling spatiotemporal chaos without supervision and maintains control of the system across bifurcations. This property of RCC allows a dynamic system to operate in parameter spaces that are difficult to control otherwise. This may be particularly interesting for the control of forced systems or dynamic systems that are chaotically perturbed. These control properties of RCC are applicable to a range of dynamic systems, thereby appearing to have far-reaching effects beyond just controlling chaos. RCC may also point to the existence of a biochemical control function of an enzyme, to stabilise the dynamics of the reaction cascade.

  15. Possibility of biological control of primocane fruiting raspberry disease caused by Fusarium sambucinum.

    Science.gov (United States)

    Shternshis, Margarita V; Belyaev, Anatoly A; Matchenko, Nina S; Shpatova, Tatyana V; Lelyak, Anastasya A

    2015-10-01

    Biological control agents are a promising alternative to chemical pesticides for plant disease suppression. The main advantage of the natural biocontrol agents, such as antagonistic bacteria compared with chemicals, includes environmental pollution prevention and a decrease of chemical residues in fruits. This study is aimed to evaluate the impact of three Bacillus strains on disease of primocane fruiting raspberry canes caused by Fusarium sambucinum under controlled infection load and uncontrolled environmental factors. Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens were used for biocontrol of plant disease in 2013 and 2014 which differed by environmental conditions. The test suspensions were 10(5) CFU/ml for each bacterial strain. To estimate the effect of biological agents on Fusarium disease, canes were cut at the end of vegetation, and the area of outer and internal lesions was measured. In addition to antagonistic effect, the strains revealed the ability to induce plant resistance comparable with chitosan-based formulation. Under variable ways of cane treatment by bacterial strains, the more effective were B. subtilis and B. licheniformis demonstrating dual biocontrol effect. However, environmental factors were shown to impact the strain biocontrol ability; changes in air temperature and humidity led to the enhanced activity of B. amyloliquefaciens. For the first time, the possibility of replacing chemicals with environmentally benign biological agents for ecologically safe control of the raspberry primocane fruiting disease was shown.

  16. Bovine milk osteopontin - Targeting bacterial adhesion for biofilm control

    DEFF Research Database (Denmark)

    Kristensen, Mathilde Frost; Meyer, Rikke Louise; Schlafer, Sebastian

    2016-01-01

    Self-performed mechanical tooth cleaning does usually not result in complete biofilm removal, due to the complex oral anatomy and the strong adhesion of the biofilm to the tooth. Therefore, different supportive measures are employed, most of which aim at the chemical eradication of bacteria...... in dental biofilms. As their bactericidal action impacts the entire oral microflora, agents that inhibit biofilm formation without killing bacteria, such as the bovine milk protein osteopontin, have gained increasing attention. Here, we investigate the adhesion of 8 bacterial species associated with dental...... subsp. paracasei, Streptococcus mitis and Streptococcus oralis with 74.0%, 62.4%, 90.0%, 89.6% and 81.5%, respectively, compared to protein-free saliva. All reductions were statistically significant (p

  17. Enzymatic Reductive Dehalogenation Controls the Biosynthesis of Marine Bacterial Pyrroles.

    Science.gov (United States)

    El Gamal, Abrahim; Agarwal, Vinayak; Rahman, Imran; Moore, Bradley S

    2016-10-12

    Enzymes capable of performing dehalogenating reactions have attracted tremendous contemporary attention due to their potential application in the bioremediation of anthropogenic polyhalogenated persistent organic pollutants. Nature, in particular the marine environment, is also a prolific source of polyhalogenated organic natural products. The study of the biosynthesis of these natural products has furnished a diverse array of halogenation biocatalysts, but thus far no examples of dehalogenating enzymes have been reported from a secondary metabolic pathway. Here we show that the penultimate step in the biosynthesis of the highly brominated marine bacterial product pentabromopseudilin is catalyzed by an unusual debrominase Bmp8 that utilizes a redox thiol mechanism to remove the C-2 bromine atom of 2,3,4,5-tetrabromopyrrole to facilitate oxidative coupling to 2,4-dibromophenol. To the best of our knowledge, Bmp8 is first example of a dehalogenating enzyme from the established genetic and biochemical context of a natural product biosynthetic pathway.

  18. Bacterial cell curvature through mechanical control of cell growth

    DEFF Research Database (Denmark)

    Cabeen, M.; Charbon, Godefroid; Vollmer, W.

    2009-01-01

    The cytoskeleton is a key regulator of cell morphogenesis. Crescentin, a bacterial intermediate filament-like protein, is required for the curved shape of Caulobacter crescentus and localizes to the inner cell curvature. Here, we show that crescentin forms a single filamentous structure...... that collapses into a helix when detached from the cell membrane, suggesting that it is normally maintained in a stretched configuration. Crescentin causes an elongation rate gradient around the circumference of the sidewall, creating a longitudinal cell length differential and hence curvature. Such curvature...... can be produced by physical force alone when cells are grown in circular microchambers. Production of crescentin in Escherichia coli is sufficient to generate cell curvature. Our data argue for a model in which physical strain borne by the crescentin structure anisotropically alters the kinetics...

  19. Hydrogen Peroxide- and Nitric Oxide-mediated Disease Control of Bacterial Wilt in Tomato Plants

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2013-12-01

    Full Text Available Reactive oxygen species (ROS generation in tomato plants by Ralstonia solanacearum infection and the role of hydrogen peroxide (H₂O₂ and nitric oxide in tomato bacterial wilt control were demonstrated. During disease development of tomato bacterial wilt, accumulation of superoxide anion (O₂− and H₂O₂ was observed and lipid peroxidation also occurred in the tomato leaf tissues. High doses of H₂O₂and sodium nitroprusside (SNP nitric oxide donor showed phytotoxicity to detached tomato leaves 1 day after petiole feeding showing reduced fresh weight. Both H₂O₂and SNP have in vitro antibacterial activities against R. solanacearum in a dose-dependent manner, as well as plant protection in detached tomato leaves against bacterial wilt by 10⁶ and 10⁷ cfu/ml of R. solanacearum. H₂O₂- and SNP-mediated protection was also evaluated in pots using soil-drench treatment with the bacterial inoculation, and relative ‘area under the disease progressive curve (AUDPC’ was calculated to compare disease protection by H₂O₂ and/or SNP with untreated control. Neither H₂O₂ nor SNP protect the tomato seedlings from the bacterial wilt, but H₂O₂+ SNP mixture significantly decreased disease severity with reduced relative AUDPC. These results suggest that H₂O₂ and SNP could be used together to control bacterial wilt in tomato plants as bactericidal agents.

  20. Fundamental principles in bacterial physiology—history, recent progress, and the future with focus on cell size control: a review

    Science.gov (United States)

    Jun, Suckjoon; Si, Fangwei; Pugatch, Rami; Scott, Matthew

    2018-05-01

    Bacterial physiology is a branch of biology that aims to understand overarching principles of cellular reproduction. Many important issues in bacterial physiology are inherently quantitative, and major contributors to the field have often brought together tools and ways of thinking from multiple disciplines. This article presents a comprehensive overview of major ideas and approaches developed since the early 20th century for anyone who is interested in the fundamental problems in bacterial physiology. This article is divided into two parts. In the first part (sections 1–3), we review the first ‘golden era’ of bacterial physiology from the 1940s to early 1970s and provide a complete list of major references from that period. In the second part (sections 4–7), we explain how the pioneering work from the first golden era has influenced various rediscoveries of general quantitative principles and significant further development in modern bacterial physiology. Specifically, section 4 presents the history and current progress of the ‘adder’ principle of cell size homeostasis. Section 5 discusses the implications of coarse-graining the cellular protein composition, and how the coarse-grained proteome ‘sectors’ re-balance under different growth conditions. Section 6 focuses on physiological invariants, and explains how they are the key to understanding the coordination between growth and the cell cycle underlying cell size control in steady-state growth. Section 7 overviews how the temporal organization of all the internal processes enables balanced growth. In the final section 8, we conclude by discussing the remaining challenges for the future in the field.

  1. Biology of Leptoypha hospita (Hemiptera: Tingidae), a Potential Biological Control Agent of Chinese Privet

    Science.gov (United States)

    Yanzhuo Zhang; James L. Hanula; Scott Horn; Kristine Braman; Jianghua Sun

    2011-01-01

    The biology of Leptoypha hospita Drake et Poor (Hemiptera: Tingidae), a potential biological control agent from China for Chinese privet, Ligustrum sinense Lour., was studied in quarantine in the United States. Both nymphs and adults feed on Chinese privet mesophyll cells that lead to a bleached appearance of leaves and dieback of branch tips. L. hospita has five...

  2. Effects of chemical and biological pesticides on plant growth parameters and rhizospheric bacterial community structure in Vigna radiata.

    Science.gov (United States)

    Singh, Sunil; Gupta, Rashi; Sharma, Shilpi

    2015-06-30

    With increasing application of pesticides in agriculture, their non-target effects on soil microbial communities are critical to soil health maintenance. The present study aimed to evaluate the effects of chemical pesticides (chlorpyrifos and cypermethrin) and a biological pesticide (azadirachtin) on growth parameters and the rhizospheric bacterial community of Vigna radiata. Qualitative and quantitative analysis by PCR-denaturing gradient gel electrophoresis (DGGE) and q-PCR, respectively, of the 16S rRNA gene and transcript were performed to study the impact of these pesticides on the resident and active rhizospheric bacterial community. While plant parameters were not affected significantly by the pesticides, a shift in the bacterial community structure was observed with an adverse effect on the abundance of 16S rRNA gene and transcripts. Chlorpyrifos showed almost complete degradation toward the end of the experiment. These non-target impacts on soil ecosystems and the fact that the effects of the biopesticide mimic those of chemical pesticides raise serious concerns regarding their application in agriculture. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Explaining Biological Functionality: Is Control Theory Enough ...

    African Journals Online (AJOL)

    I argue that the etiological approach, as understood in terms of control theory, suffers from a problem of symmetry, by which function can equally well be placed in the environment as in the organism. Focusing on the autonomy view, I note that it can be understood to some degree in terms of control theory in its version called ...

  4. Configuration of biological wastewater treatment line and influent composition as the main factors driving bacterial community structure of activated sludge.

    Science.gov (United States)

    Jaranowska, Paulina; Cydzik-Kwiatkowska, Agnieszka; Zielińska, Magdalena

    2013-07-01

    The structure of microbial consortia in wastewater treatment facilities is a resultant of environmental conditions created by the operational parameters of the purification process. In the research, activated sludge from nine Polish wastewater treatment plants (WWTPs) was investigated at a molecular level to determine the impact of the complexity of biological treatment line and the influent composition on the species structure and the diversity of bacterial consortia. The community fingerprints and technological data were subjected to the canonical correspondence and correlation analyses. The number of separated biological processes realized in the treatment line and the presence of industrial wastewater in the influent were the key factors determining the species structure of total and ammonia-oxidizing bacteria in biomass. The N2O-reducers community composition depended significantly on the design of the facility; the highest species richness of denitrifiers was noted in the WWTPs with separated denitrification tanks. The contribution of industrial streams to the inflow affected the diversity of total and denitrifying bacterial consortia and diminished the diversity of ammonia oxidizers. The obtained data are valuable for engineers since they revealed the main factors, including the design of wastewater treatment plant, influencing the microbial groups critical for the stability of purification processes.

  5. Microbiome studies in the biological control of plant pathogens

    Science.gov (United States)

    Biological control of plant pathogens, although it has been a successful alternative that has allowed to select microorganisms for the generation of bioproducts and to understand multiple biological mechanisms, cannot be considered as a strategy defined only from the selection of a range of cultiva...

  6. Insect pathogens as biological control agents: Back to the future.

    Science.gov (United States)

    Lacey, L A; Grzywacz, D; Shapiro-Ilan, D I; Frutos, R; Brownbridge, M; Goettel, M S

    2015-11-01

    nematode strain improvement via enhancement and stabilization of beneficial traits. Innovative research has also yielded insights into the fundamentals of EPN biology including major advances in genomics, nematode-bacterial symbiont interactions, ecological relationships, and foraging behavior. Additional research is needed to leverage these basic findings toward direct improvements in microbial control. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Arms Control: US and International efforts to ban biological weapons

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    The Bacteriological (Biological) and Toxin Weapons Convention, the treaty that bans the development, production, and stockpiling and acquisition of biological weapons was opened for signature in 1972 and came into force in 1975 after being ratified by 22 governments, including the depository nations of the USA, the United Kingdom, and the former Soviet Union. In support of the Convention, the USA later established export controls on items used to make biological weapons. Further, in accordance with the 1990 President`s Enhanced Proliferation Control Initiative, actions were taken to redefine and expand US export controls, as well as to encourage multilateral controls through the Australia Group. Thus far, the Convention has not been effective in stopping the development of biological weapons. The principal findings as to the reasons of the failures of the Convention are found to be: the Convention lacks universality, compliance measures are effective, advantage of verification may outweigh disadvantages. Recommendations for mitigating these failures are outlined in this report.

  8. Biological control of tortricids and aphids in strawberries

    DEFF Research Database (Denmark)

    Sigsgaard, Lene; Enkegaard, Annie; Eilenberg, Jørgen

    Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising....

  9. Control of biofouling by xanthine oxidase on seawater reverse osmosis membranes from a desalination plant: enzyme production and screening of bacterial isolates from the full-scale plant.

    Science.gov (United States)

    Nagaraj, V; Skillman, L; Li, D; Xie, Z; Ho, G

    2017-07-01

    Control of biofouling on seawater reverse osmosis (SWRO) membranes is a major challenge as treatments can be expensive, damage the membrane material and often biocides do not remove the polymers in which bacteria are embedded. Biological control has been largely ignored for biofouling control. The objective of this study was to demonstrate the effectiveness of xanthine oxidase enzyme against complex fouling communities and then identify naturally occurring bacterial strains that produce the free radical generating enzyme. Initially, 64 bacterial strains were isolated from different locations of the Perth Seawater Desalination Plant. In our preceding study, 25/64 isolates were selected from the culture collection as models for biofouling studies, based on their prevalence in comparison to the genomic bacterial community. In this study, screening of these model strains was performed using a nitroblue tetrazolium assay in the presence of hypoxanthine as substrate. Enzyme activity was measured by absorbance. Nine of 25 strains tested positive for xanthine oxidase production, of which Exiguobacterium from sand filters and Microbacterium from RO membranes exhibited significant levels of enzyme production. Other genera that produced xanthine oxidase were Marinomonas, Pseudomonas, Bacillus, Pseudoalteromonas and Staphylococcus. Strain variations were observed between members of the genera Microbacterium and Bacillus. Xanthine oxidase, an oxidoreductase enzyme that generates reactive oxygen species, is endogenously produced by many bacterial species. In this study, production of the enzyme by bacterial isolates from a full-scale desalination plant was investigated for potential use as biological control of membrane fouling in seawater desalination. We have previously demonstrated that free radicals generated by a commercially available xanthine oxidase in the presence of a hypoxanthine substrate, effectively dispersed biofilm polysaccharides on industrially fouled membranes

  10. Mitochondria: An Organelle of Bacterial Origin Controlling Inflammation

    Directory of Open Access Journals (Sweden)

    Alain Meyer

    2018-04-01

    Full Text Available Inflammation is a cellular and molecular response to infection and/or tissues injury. While a suited inflammatory response in intensity and time allows for killing pathogens, clearing necrotic tissue, and healing injury; an excessive inflammatory response drives various diseases in which inflammation and tissues damages/stress self-sustain each other. Microbes have been poorly implied in non-resolving inflammation, emphasizing the importance of endogenous regulation of inflammation. Mitochondria have been historically identified as the main source of cellular energy, by coupling the oxidation of fatty acids and pyruvate with the production of high amount of adenosine triphosphate by the electron transport chain. Mitochondria are also the main source of reactive oxygen species. Interestingly, research in the last decade has highlighted that since its integration in eukaryote cells, this organelle of bacterial origin has not only been tolerated by immunity, but has also been placed as a central regulator of cell defense. In intact cells, mitochondria regulate cell responses to critical innate immune receptors engagement. Downstream intracellular signaling pathways interact with mitochondrial proteins and are tuned by mitochondrial functioning. Moreover, upon cell stress or damages, mitochondrial components are released into the cytoplasm or the extra cellular milieu, where they act as danger signals when recognized by innate immune receptors. Finally, by regulating the energetic state of immunological synapse between dendritic cells and lymphocytes, mitochondria regulate the inflammation fate toward immunotolerance or immunogenicity. As dysregulations of these processes have been recently involved in various diseases, the identification of the underlying mechanisms might open new avenues to modulate inflammation.

  11. Isolation of microorganisms for biological control the moniliophthora roreri

    OpenAIRE

    suarez contreras, liliana yanet; Rangel Riaño, Alba Luz

    2014-01-01

    Moniliophlhora roreri is the causal agent of cocoa Moniliasis, which produces losses of up to 60% of the crop, as it affects only its commercial product, the cob. Biological control appears as an alternative management, using endophytic microorganisms. The reason because of this research came up was that it was aimed to isolate microorganisms with antagonist potential for biological control towards the phytopathogen M. roreri in Norte de Santander. This is done through isolation and identifica...

  12. Biology and control of hemlock woolly adelgid

    Science.gov (United States)

    Nathan P. Havill; Ligia C. Vieira; Scott M. Salom

    2014-01-01

    This publication is a substantial revision of FHTET 2001-03, Hemlock Woolly Adelgid, which was published in 2001. This publication contains information on the native range of hemlock and range of hemlock woolly adelgid, the importance of hemlocks in eastern forest ecosystems, and on hosts, life cycle, control, and population trends of the hemlock woolly adelgid.

  13. Controllability and observability of Boolean networks arising from biology

    Science.gov (United States)

    Li, Rui; Yang, Meng; Chu, Tianguang

    2015-02-01

    Boolean networks are currently receiving considerable attention as a computational scheme for system level analysis and modeling of biological systems. Studying control-related problems in Boolean networks may reveal new insights into the intrinsic control in complex biological systems and enable us to develop strategies for manipulating biological systems using exogenous inputs. This paper considers controllability and observability of Boolean biological networks. We propose a new approach, which draws from the rich theory of symbolic computation, to solve the problems. Consequently, simple necessary and sufficient conditions for reachability, controllability, and observability are obtained, and algorithmic tests for controllability and observability which are based on the Gröbner basis method are presented. As practical applications, we apply the proposed approach to several different biological systems, namely, the mammalian cell-cycle network, the T-cell activation network, the large granular lymphocyte survival signaling network, and the Drosophila segment polarity network, gaining novel insights into the control and/or monitoring of the specific biological systems.

  14. The interplay between biological and physical scenarios of bacterial death induced by non-thermal plasma

    Czech Academy of Sciences Publication Activity Database

    Lunov, Oleg; Zablotskyy, Vitaliy A.; Churpita, Olexandr; Jäger, Aleš; Polívka, Leoš; Syková, E.; Dejneka, Alexandr; Kubinová, Šárka

    2016-01-01

    Roč. 82, Mar (2016), s. 71-83 ISSN 0142-9612 R&D Projects: GA MŠk LO1409; GA MŠk(CZ) LM2011026 Grant - others:FUNBIO(XE) CZ.2.16/3.1.00/21568; AV ČR(CZ) Fellowship J. E. Purkyně Institutional support: RVO:68378271 Keywords : non-thermal plasma * bacteria * cytotoxicity * apoptosis * bacterial inactivation * reactive oxygen species (ROS) Subject RIV: BO - Biophysics Impact factor: 8.402, year: 2016

  15. Conventional and nonconventional strategies for controlling bacterial contamination in fuel ethanol fermentations.

    Science.gov (United States)

    Ceccato-Antonini, Sandra Regina

    2018-05-25

    Ethanol bio-production in Brazil has some unique characteristics that inevitably lead to bacterial contamination, which results in the production of organic acids and biofilms and flocculation that impair the fermentation yield by affecting yeast viability and diverting sugars to metabolites other than ethanol. The ethanol-producing units commonly give an acid treatment to the cells after each fermentative cycle to decrease the bacterial number, which is not always effective. An alternative strategy must be employed to avoid bacterial multiplication but must be compatible with economic, health and environmental aspects. This review analyzes the issue of bacterial contamination in sugarcane-based fuel ethanol fermentation, and the potential strategies that may be utilized to control bacterial growth besides acid treatment and antibiotics. We have emphasized the efficiency and suitability of chemical products other than acids and those derived from natural sources in industrial conditions. In addition, we have also presented bacteriocins, bacteriophages, and beneficial bacteria as non-conventional antimicrobial agents to mitigate bacterial contamination in the bioethanol industry.

  16. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi; Shimizu, Takashi; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yamashita, Takao

    1997-03-01

    To investigate the effect of local irradiation with ion beams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ion beams suggests that the efficient pollen envelope damages would be induced at the range-end of ion beams. (author)

  17. New bacterial products for control of pecan pests

    Science.gov (United States)

    Pecans are economically the most important native nut crop in the USA. Among the major concerns are the pecan weevil (Curculio caryae), pecan aphids, and diseases such as pecan scab, Venturia effusa. These pests are generally controlled with broad spectrum chemicals. The chemical pesticides can be...

  18. Integrated Control of Fire Blight with Bacterial Antagonists and Oxytetracycline

    Science.gov (United States)

    In the Pacific Northwest of the United States, the antibiotic streptomycin provided excellent control of fire blight until resistant isolates of Erwinia amylovora were prevalent. Oxytetracycline (Mycoshield) is now sprayed as an alternative antibiotic. We found that the duration of inhibitory acti...

  19. A Population Biology Perspective on the Stepwise Infection Process of the Bacterial Pathogen Pasteuria ramosa in Daphnia.

    Science.gov (United States)

    Ebert, Dieter; Duneau, David; Hall, Matthew D; Luijckx, Pepijn; Andras, Jason P; Du Pasquier, Louis; Ben-Ami, Frida

    2016-01-01

    The infection process of many diseases can be divided into series of steps, each one required to successfully complete the parasite's life and transmission cycle. This approach often reveals that the complex phenomenon of infection is composed of a series of more simple mechanisms. Here we demonstrate that a population biology approach, which takes into consideration the natural genetic and environmental variation at each step, can greatly aid our understanding of the evolutionary processes shaping disease traits. We focus in this review on the biology of the bacterial parasite Pasteuria ramosa and its aquatic crustacean host Daphnia, a model system for the evolutionary ecology of infectious disease. Our analysis reveals tremendous differences in the degree to which the environment, host genetics, parasite genetics and their interactions contribute to the expression of disease traits at each of seven different steps. This allows us to predict which steps may respond most readily to selection and which steps are evolutionarily constrained by an absence of variation. We show that the ability of Pasteuria to attach to the host's cuticle (attachment step) stands out as being strongly influenced by the interaction of host and parasite genotypes, but not by environmental factors, making it the prime candidate for coevolutionary interactions. Furthermore, the stepwise approach helps us understanding the evolution of resistance, virulence and host ranges. The population biological approach introduced here is a versatile tool that can be easily transferred to other systems of infectious disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Potential of Endophytic Bacterial to Control Lesion Nematode (Pratylenchus brachyurus on Patchouli

    Directory of Open Access Journals (Sweden)

    RITA HARNI

    2007-03-01

    Full Text Available Root lesion nematode (Pratylenchus brachyurus is one of the most important pathogens of patchouli that caused significant losses. Studies on the potential of endophytic bacterial to control P. brachyurus on patchouli had been conducted. To evaluate the effectiveness of endophytic bacterial against to P. brachyurus on patchouli, nine isolates of bacteria ( NJ2, NJ25, NJ41, NJ46, NJ57, NA22, ERB21, ES32, and E26 were applied by deeping root seedling into bacterial suspension. A study of the physiological characteristics of nine isolates was conducted by using specific medium. The results showed that endophytic bacterial was significantly reduced the population of P. brachyurus and all isolates bacterial promoted growth of patchouli (shoot weight, root weight, and root length. Four isolates, i.e. Bacillus NJ46, Bacillus Na22, Bacillus NJ2, and Bacillus NJ57 were among the potential control agents that reduced nematode populations as much as 68.1-73.9%. Almost all of the isolated bacteria from patchouli roots were able to solubilizing phosphate, while some of them had the ability to produce chitinase, cellulase, protease, HCN, and fluorescency.

  1. Local and global control of ecological and biological networks

    OpenAIRE

    Alessandro Ferrarini

    2014-01-01

    Recently, I introduced a methodological framework so that ecological and biological networks can be controlled both from inside and outside by coupling network dynamics and evolutionary modelling. The endogenous control requires the network to be optimized at the beginning of its dynamics (by acting upon nodes, edges or both) so that it will then go inertially to the desired state. Instead, the exogenous control requires that exogenous controllers act upon the network at each time step. By th...

  2. Synthetic biology approaches for protein production optimization in bacterial cell factories

    DEFF Research Database (Denmark)

    Rennig, Maja; Andersen, Mikael Rørdam

    devices and their fusion to antibiotic selection markers enables subsequent selection of high-expressing constructs. The approach is a simple and inexpensive alternative to advanced screening techniques. In addition, a second synthetic biology approach provides the means for fast and efficient plasmid...

  3. Common and distinguishing features of the bacterial and fungal communities in biological soil crusts and shrub root zone soils

    Science.gov (United States)

    Steven, Blaire; Gallegos-Graves, La Verne; Yeager, Chris; Belnap, Jayne; Kuske, Cheryl R.

    2013-01-01

    Soil microbial communities in dryland ecosystems play important roles as root associates of the widely spaced plants and as the dominant members of biological soil crusts (biocrusts) colonizing the plant interspaces. We employed rRNA gene sequencing (bacterial 16S/fungal large subunit) and shotgun metagenomic sequencing to compare the microbial communities inhabiting the root zones of the dominant shrub, Larrea tridentata (creosote bush), and the interspace biocrusts in a Mojave desert shrubland within the Nevada Free Air CO2 Enrichment (FACE) experiment. Most of the numerically abundant bacteria and fungi were present in both the biocrusts and root zones, although the proportional abundance of those members differed significantly between habitats. Biocrust bacteria were predominantly Cyanobacteria while root zones harbored significantly more Actinobacteria and Proteobacteria. Pezizomycetes fungi dominated the biocrusts while Dothideomycetes were highest in root zones. Functional gene abundances in metagenome sequence datasets reflected the taxonomic differences noted in the 16S rRNA datasets. For example, functional categories related to photosynthesis, circadian clock proteins, and heterocyst-associated genes were enriched in the biocrusts, where populations of Cyanobacteria were larger. Genes related to potassium metabolism were also more abundant in the biocrusts, suggesting differences in nutrient cycling between biocrusts and root zones. Finally, ten years of elevated atmospheric CO2 did not result in large shifts in taxonomic composition of the bacterial or fungal communities or the functional gene inventories in the shotgun metagenomes.

  4. Alternative substrates of bacterial sulphate reduction suitable for the biological-chemical treatment of acid mine drainage

    Directory of Open Access Journals (Sweden)

    Alena Luptakova

    2012-12-01

    Full Text Available The impacts of AMD pollution on biological systems are mostly severe and the problem may persist from many decadesto thousands of years. Consequently AMD prior to being released into the environment must be treated to meet government standardsfor the amount of metal and non-metal ions contained in the water. One of the best available technologies for the removal of metals fromAMD is precipitation as metal sulphides. SRB applications for AMD treatment involve a few principal stages. The first stageis the cultivation of SRB i.e. the bacterial sulphate reduction. At the laboratory conditions the sodium lactate is the energetic substratefor the growth of bacteria. Its price is not economic for the application in the practice and is needed investigate the alternativesubstitutes. The aim of this work was the cultivation of SRB using the selected energetic substrates such as: calcium lactate, ethanol,saccharose, glucose and whey. Experimental studies confirm that in the regard to the amount of reduced sulphates the calcium lactateand ethanol are the best alternative substrates for the bacterial sulphate-reduction.

  5. [The bacterial biofilm and the possibilities of chemical plaque control. Literature review].

    Science.gov (United States)

    Gera, István

    2008-06-01

    Most microorganisms in the oral cavity attach to surfaces and form matrix-embedded biofilms. Biofilms are structured and spatially organized, composed of consortia of interacting microorganisms. The properties of the mass of biofilm are different from that of the simple sum of the component species. The older the plaque (biofilm) is the more structurally organized and become more resistant to environmental attacks. The bacterial community favors the growth of obligatory anaerobic microorganisms. The most effective means of the elimination of matured biofilm is the mechanical disruption of the interbacterial protective matrix and removal of bacterial colonies. The antiseptic agents are primarily effective in the prevention of biofilm formation and anticipation of the maturation of the bacterial plaque. Bacteria in matured biofilms are less susceptible to antimicrobial agents because several physical and biological factors protect the bacterial consortia. To kill bacteria in a matured, well organized biofilm, significantly higher concentration and longer exposition are required. Antiseptic mouthrinses in a conventional dose and time can only reach the superficial bacteria while the bacteria in the depth of the biofilm remains intact. Therefore, the efficacy of any antiseptic mouthwash depends not just on its microbicidal properties demonstrated in vitro, but also on its ability to penetrate the organized biofilm on the teeth. Recent studies have demonstrated that both bisbiguanid compounds and essential oils are capable of penetrating the biofilm, and reduce established plaque and gingivitis. The essential oils showed high penetrability and were more effective on organized biofilm than stannous fluorides or triclosan copolymer antiplaque agents.

  6. Biological control by ( Coccinella algerica , Kovar 1977) against the ...

    African Journals Online (AJOL)

    Inputs from chemicals, particularly pesticides, to control crop pests have adverse effects on soil and the environment, among others. To reduce pest attacks, biological control with indigenous predators is the alternative and the cleanest, most environmentally friendly and ecologically balanced way. In order to achieve this ...

  7. Augmentative biological control of arthropods in Latin America

    NARCIS (Netherlands)

    Lenteren, van J.C.; Bueno, V.H.P.

    2003-01-01

    Augmentative forms of biological control, where natural enemies are periodically introduced, are applied over large areas in various cropping systems in Latin America. About 25% of the world area under augmentative control is situated in this region. Well-known examples are the use of species of the

  8. Nematodes for the biological control of the woodwasp, Sirex noctilio

    Science.gov (United States)

    Robin A. Bedding

    2007-01-01

    The tylenchid nematode Beddingia (Deladenus) siricidicola (Bedding) is by far the most important control agent of Sirex noctilio F., a major pest of pine plantations. It sterilizes female sirex, is density dependent, can achieve nearly 100 percent parasitism and, as a result of its complicated biology can be readily manipulated for sirex control. Bedding and Iede (2005...

  9. The Prc and RseP proteases control bacterial cell-surface signalling activity.

    NARCIS (Netherlands)

    Bastiaansen, K.C.J.T.; Ibañez, A.; Ramos, JL; Bitter, W.; Llamas, M.A.

    2014-01-01

    Summary: Extracytoplasmic function (ECF) sigma factors play a key role in the regulation of vital functions in the bacterial response to the environment. In Gram-negative bacteria, activity of these sigma factors is often controlled by cell-surface signalling (CSS), a regulatory system that also

  10. Role of the gut microbiota in host appetite control: bacterial growth to animal feeding behaviour.

    Science.gov (United States)

    Fetissov, Sergueï O

    2017-01-01

    The life of all animals is dominated by alternating feelings of hunger and satiety - the main involuntary motivations for feeding-related behaviour. Gut bacteria depend fully on their host for providing the nutrients necessary for their growth. The intrinsic ability of bacteria to regulate their growth and to maintain their population within the gut suggests that gut bacteria can interfere with molecular pathways controlling energy balance in the host. The current model of appetite control is based mainly on gut-brain signalling and the animal's own needs to maintain energy homeostasis; an alternative model might also involve bacteria-host communications. Several bacterial components and metabolites have been shown to stimulate intestinal satiety pathways; at the same time, their production depends on bacterial growth cycles. This short-term bacterial growth-linked modulation of intestinal satiety can be coupled with long-term regulation of appetite, controlled by the neuropeptidergic circuitry in the hypothalamus. Indeed, several bacterial products are detected in the systemic circulation, which might act directly on hypothalamic neurons. This Review analyses the data relevant to possible involvement of the gut bacteria in the regulation of host appetite and proposes an integrative homeostatic model of appetite control that includes energy needs of both the host and its gut bacteria.

  11. Use of hebicides for control of banana bacterial wilt in Uganda ...

    African Journals Online (AJOL)

    Use of hebicides for control of banana bacterial wilt in Uganda. W Okurut, W K Tushemereirwe, V Aritua, P Ragama. Abstract. No Abstract. African Crop Science Jouranl Vol. 14 (2) 2006: pp. 143-150. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  12. Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma : A nested case-control study

    NARCIS (Netherlands)

    Fedirko, Veronika; Tran, Hao Quang; Gewirtz, Andrew T.; Stepien, Magdalena; Trichopoulou, Antonia; Aleksandrova, Krasimira; Olsen, Anja; Tjønneland, Anne; Overvad, Kim; Carbonnel, Franck; Boutron-Ruault, Marie Christine; Severi, Gianluca; Kühn, Tilman; Kaaks, Rudolf; Boeing, Heiner; Bamia, Christina; Lagiou, Pagona; Grioni, Sara; Panico, Salvatore; Palli, Domenico; Tumino, Rosario; Naccarati, Alessio; Peeters, Petra H.; Bueno-de-Mesquita, H. B.; Weiderpass, Elisabete; Castaño, José María Huerta; Barricarte, Aurelio; Sánchez, María José; Dorronsoro, Miren; Quirós, J. Ramón; Agudo, Antonio; Sjöberg, Klas; Ohlsson, Bodil; Hemmingsson, Oskar; Werner, Mårten; Bradbury, Kathryn E.; Khaw, Kay Tee; Wareham, Nick; Tsilidis, Konstantinos K.; Aune, Dagfinn; Scalbert, Augustin; Romieu, Isabelle; Riboli, Elio; Jenab, Mazda

    2017-01-01

    Background: Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking. Methods: We used a case-control study design nested within a large

  13. Biological control of Mycosphaerella fragariae in strawberry culture

    Directory of Open Access Journals (Sweden)

    Anderson Luis Heling

    2015-12-01

    Full Text Available The Mycosphaerella spot is one of the main foliar diseases of strawberry, degrating great leaf regions and reducing the photosynthetic area. Its control is mainly by the use of chemical fungicides, but, due the increasing demand for food free of pesticide, alternative control methods have been researched, such as biological control. This work aimed to evaluate the effect on strawberry plants, treated with the biological control agents Bacillus cereus, Saccharomyces boulardii and Saccharomyces cerevisiae, in the severity of Mycosphaerella fragariae, productivity and in the activity of β-1.3 glucanases, peroxidases and chitinases enzymes. It was verified that S. cerevisiae and B. cereus treatments were similar to fungicide for disease control. However, even reducing the severity of the disease, there was no increase in productivity, and the different control agents do not cause changes in the evaluated defense mechanisms.

  14. Viral control of bacterial biodiversity - Evidence from a nutrient enriched mesocosm experiment

    DEFF Research Database (Denmark)

    Sandaa, R.-A.; Gómez-Consarnau, L.; Pinhassi, J.

    2009-01-01

    . As predicted, the total number of viral populations was the same in all treatments, while the composition of the viral community varied. Our results support the theoretical prediction that there is one control mechanism for the number of niches for coexisting virus-host pairs (top-down control), and another......We demonstrate here results showing that bottom-up and top-down control mechanisms can operate simultaneously and in concert in marine microbial food webs, controlling prokaryote diversity by a combination of viral lysis and substrate limitation. Models in microbial ecology predict that a shift...... in the type of bacterial growth rate limitation is expected to have a major effect on species composition within the community of bacterial hosts, with a subsequent shift in the composition of the viral community. Only moderate effects would, however, be expected in the absolute number of coexisting virus...

  15. Influence of Uranium on Bacterial Communities: A Comparison of Natural Uranium-Rich Soils with Controls

    Science.gov (United States)

    Mondani, Laure; Benzerara, Karim; Carrière, Marie; Christen, Richard; Mamindy-Pajany, Yannick; Février, Laureline; Marmier, Nicolas; Achouak, Wafa; Nardoux, Pascal; Berthomieu, Catherine; Chapon, Virginie

    2011-01-01

    This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uranium-phosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil. PMID:21998695

  16. Genes as early responders regulate quorum-sensing and control bacterial cooperation in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Kelei Zhao

    Full Text Available Quorum-sensing (QS allows bacterial communication to coordinate the production of extracellular products essential for population fitness at higher cell densities. It has been generally accepted that a significant time duration is required to reach appropriate cell density to activate the relevant quiescent genes encoding these costly but beneficial public goods. Which regulatory genes are involved and how these genes control bacterial communication at the early phases are largely un-explored. By determining time-dependent expression of QS-related genes of the opportunistic pathogen Pseudomonas aerugionsa, we show that the induction of social cooperation could be critically influenced by environmental factors to optimize the density of population. In particular, small regulatory RNAs (RsmY and RsmZ serving as early responders, can promote the expression of dependent genes (e.g. lasR to boost the synthesis of intracellular enzymes and coordinate instant cooperative behavior in bacterial cells. These early responders, acting as a rheostat to finely modulate bacterial cooperation, which may be quickly activated under environment threats, but peter off when critical QS dependent genes are fully functional for cooperation. Our findings suggest that RsmY and RsmZ critically control the timing and levels of public goods production, which may have implications in sociomicrobiology and infection control.

  17. Biologically plausible learning in neural networks: a lesson from bacterial chemotaxis.

    Science.gov (United States)

    Shimansky, Yury P

    2009-12-01

    Learning processes in the brain are usually associated with plastic changes made to optimize the strength of connections between neurons. Although many details related to biophysical mechanisms of synaptic plasticity have been discovered, it is unclear how the concurrent performance of adaptive modifications in a huge number of spatial locations is organized to minimize a given objective function. Since direct experimental observation of even a relatively small subset of such changes is not feasible, computational modeling is an indispensable investigation tool for solving this problem. However, the conventional method of error back-propagation (EBP) employed for optimizing synaptic weights in artificial neural networks is not biologically plausible. This study based on computational experiments demonstrated that such optimization can be performed rather efficiently using the same general method that bacteria employ for moving closer to an attractant or away from a repellent. With regard to neural network optimization, this method consists of regulating the probability of an abrupt change in the direction of synaptic weight modification according to the temporal gradient of the objective function. Neural networks utilizing this method (regulation of modification probability, RMP) can be viewed as analogous to swimming in the multidimensional space of their parameters in the flow of biochemical agents carrying information about the optimality criterion. The efficiency of RMP is comparable to that of EBP, while RMP has several important advantages. Since the biological plausibility of RMP is beyond a reasonable doubt, the RMP concept provides a constructive framework for the experimental analysis of learning in natural neural networks.

  18. Biological characterization of a new radioactive labeling reagent for bacterial penicillin-binding proteins

    International Nuclear Information System (INIS)

    Preston, D.A.; Wu, C.Y.; Blaszczak, L.C.; Seitz, D.E.; Halligan, N.G.

    1990-01-01

    Radiolabeled penicillin G is widely used as the imaging agent in penicillin-binding protein (PBP) assays. The disadvantages of most forms of labeled penicillin G are instability on storage and the long exposure times usually required for autoradiography or fluorography of electrophoretic gels. We investigated the utility of radioiodinated penicillin V as an alternative reagent. Radioiodination of p-(trimethylstannyl)penicillin V with [ 125 I]Na, using a modification of the chloramine-T method, is simple, high yielding, and site specific. We demonstrated the general equivalence of commercially obtained [ 3 H]penicillin G and locally synthesized [ 125 I]penicillin V (IPV) in their recognition of bacterial PBPs. Profiles of PBPs in membranes from Bacteroides fragilis, Escherichia coli, Providencia rettgeri, Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecalis, and Enterococcus faecium labeled with IPV or [3H]penicillin G were virtually identical. Use of IPV as the imaging agent in competition experiments for determination of the affinities of various beta-lactam antibiotics for the PBPs of E. coli yielded results similar to those obtained in experiments with [ 3 H]penicillin G. Dried electrophoretic gels from typical PBP experiments, using IPV at 37.3 Ci/mmol and 30 micrograms/ml, exposed X-ray film in 8 to 24 h. The stability of IPV on storage at 4 degrees C was inversely proportional to specific activity. At 37.3 Ci/mmol and 60 micrograms/ml, IPV retained useful activity for at least 60 days at 4 degrees C. IPV represents a practical and stable reagent for rapid PBP assays

  19. Bacterial exposure to metal-oxide nanoparticles: Methods, physical interactions, and biological effects

    Science.gov (United States)

    Horst, Allison Marie

    Nanotechnology is a major endeavor of this century, with proposed applications in fields ranging from agriculture to energy to medicine. Nanoscale titanium dioxide (nano-TiO2) is among the most widely produced nanoparticles worldwide, and already exists in consumer products including impermanent personal care products and surface coatings. Inevitably, nano-TiO2 will be transported into the environment via consumer or industrial waste, where its effects on organisms are largely unknown. Out of concern for the possible ill-effects of nanoparticles in the environment, there is now a field of study in nanotoxicology. Bacteria are ideal organisms for nanotoxicology research because they are environmentally important, respond rapidly to intoxication, and provide evidence for effects in higher organisms. My doctoral research focuses on the effects and interactions of nano-TiO2 in aqueous systems with planktonic bacteria. This dissertation describes four projects and the outcomes of the research: (1) A discovery, using a combination of environmental- and cryogenic-scanning electron microscopy and dynamic light scattering (DLS), that initially agglomerated nano-TiO2 is dispersed upon bacterial contact, as nanoparticles preferentially sorbed to cell surfaces. (2) Establishment of a method to disperse nanoparticles in an aqueous culture medium for nanotoxicology studies. A combination of electrostatic repulsion, steric hindrance and sonication yielded a high initial level of nano-TiO2 dispersion (i.e. E. coli growth and membrane processes. Together, this research is towards: better understanding outcomes of interactions between nanoparticles and bacteria, advancing methods in the relatively new field of nanotoxicology that are transferable to other nanoparticle and media chemistries, and improving our understanding of structure-activity relationships (e.g. size and doping effects) leading to intoxication in environmental organisms.

  20. Duplex recombinase polymerase amplification assays incorporating competitive internal controls for bacterial meningitis detection.

    Science.gov (United States)

    Higgins, Owen; Clancy, Eoin; Forrest, Matthew S; Piepenburg, Olaf; Cormican, Martin; Boo, Teck Wee; O'Sullivan, Nicola; McGuinness, Claire; Cafferty, Deirdre; Cunney, Robert; Smith, Terry J

    2018-04-01

    Recombinase polymerase amplification (RPA) is an isothermal nucleic acid amplification technology that provides rapid and robust infectious disease pathogen detection, ideal for point-of-care (POC) diagnostics in disease-prevalent low-resource countries. We have developed and evaluated three duplex RPA assays incorporating competitive internal controls for the detection of leading bacterial meningitis pathogens. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae singleplex RPA assays were initially developed and evaluated, demonstrating 100% specificity with limits of detection of 4.1, 8.5 and 3.9 genome copies per reaction, respectively. Each assay was further developed into internally controlled duplex RPA assays via the incorporation of internal amplification control templates. Clinical performance of each internally controlled duplex RPA assay was evaluated by testing 64 archived PCR-positive clinical samples. Compared to real-time PCR, all duplex RPA assays demonstrated 100% diagnostic specificity, with diagnostic sensitivities of 100%, 86.3% and 100% for the S. pneumoniae, N. meningitidis and H. influenzae assays, respectively. This study details the first report of internally controlled duplex RPA assays for the detection of bacterial meningitis pathogens: S. pneumoniae, N. meningitidis and H. influenzae. We have successfully demonstrated the clinical diagnostic utility of each duplex RPA assay, introducing effective diagnostic technology for POC bacterial meningitis identification in disease-prevalent developing countries. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Controlling Bacterial Pathogens in Water for Reuse: Treatment Technologies for Water Recirculation in the Blue Diversion Autarky Toilet

    Directory of Open Access Journals (Sweden)

    Mi T. Nguyen

    2017-12-01

    Full Text Available HighlightBacterial growth in fecally-contaminated water is highly variable and dependent on several factors.Regrowth occurs after chlorination (low doses, no residual.Indigenous microbial communities variably impact bacterial growth.A combination of treatments can both inactivate and inhibit growth.The Blue Diversion AUTARKY Toilet is a urine-diverting toilet with on-site treatment. The toilet is being developed to provide a safe and affordable sanitation technology for people who lack access to sewer-based sanitation. Water used for personal hygiene, hand washing, and flushing to rinse urine- and feces-collection bowls is treated, stored, and recycled for reuse to reduce reliance on external water supplies. The system provides an opportunity to investigate hygiene of water for reuse following treatment. Treatment in the toilet includes a Biologically Activated Membrane Bioreactor (BAMBi followed by a secondary treatment technology. To identify effective secondary treatment, three options, including granular activated carbon (GAC only, GAC+chlorine (sodium hypochlorite, and GAC+electrolysis are considered based on the bacterial inactivation and growth inhibition efficiency. Four different hygiene-relevant bacteria are tested: Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Salmonella typhimurium. Our evaluation demonstrates that—despite treatment of water with the BAMBi—E. coli, P. aeruginosa, and S. typhimurium have the potential to grow during storage in the absence of microbial competition. Including the indigenous microbial community influences bacterial growth in different ways: E. coli growth decreases but P. aeruginosa growth increases relative to no competition. The addition of the secondary treatment options considerably improves water quality. A column of GAC after the BAMBi reduces E. coli growth potential by 2 log10, likely due to the reduction of carbon sources. Additional treatments including chlorination

  2. Conservation biological control and enemy diversity on a landscape scale

    NARCIS (Netherlands)

    Tscharntke, T.; Bommarco, R.; Clough, Y.; Crist, T.O.; Kleijn, D.; Rand, T.A.; Tylianakis, J.M.; Nouhuys, S.; Vidal, S.

    2007-01-01

    Conservation biological control in agroecosystems requires a landscape management perspective, because most arthropod species experience their habitat at spatial scales beyond the plot level, and there is spillover of natural enemies across the crop–noncrop interface. The species pool in the

  3. Methylene Diphosphonate Chemical and Biological control of MDP complex

    International Nuclear Information System (INIS)

    Aungurarat, Angkanan; Ngamprayad, Tippanan

    2000-01-01

    Technetium-9 9m MDP easy prepared from MDP kits which different sources such as OAP (In house), SIGMA. The resulting Tc 9 9m -MDP preparations were controlled in chemical and biological tests to compare the different results in these cases: radiochemical purity, the quantity of starting material and biodistribution result

  4. Biological control agent for mosquito larvae: Review on the killifish ...

    African Journals Online (AJOL)

    This review attempts to give an account on the recent advances on the killifish Aphanius dispar dispar as a biological control agent for mosquito larvae. Thirty six (36) articles of literature (scientific papers, technical and workshop reports) on this subject covering the period between 1980 and 2009 were reviewed.

  5. Stakeholder perceptions: Biological control of Russian olive (Elaeagnus angustifolia)

    Science.gov (United States)

    Sharlene E. Sing; Kevin J. Delaney

    2016-01-01

    An online survey was distributed through email lists provided by various stakeholder groups on behalf of the International Consortium for Biological Control of Russian Olive in spring of 2012. A total of 392 respondents replied from 24 U.S. states and 1 Canadian province. Questions posed in the survey were designed to identify and categorize 1) stakeholders by...

  6. The perception of corn farmers about biological control of Caradrina ...

    African Journals Online (AJOL)

    The purpose of this study was to analyze the perception of corn farmers about biological control of Caradrina by Braconid in Dezful Township, Khouzestan Province, Iran. The method used in this study was correlative descriptive and causal relation. A random sample of Dezful township corn farmers of Khouzestan Province, ...

  7. Funding needed for assessments of weed biological control

    Science.gov (United States)

    John L. Maron; Dean E. Pearson; Stephen M. Hovick; Walter P. Carson

    2010-01-01

    Invasive non-native plants are a serious economic and ecological problem worldwide, and major efforts are therefore devoted to reducing weed abundance in agricultural and natural settings. Effective options for reducing invasive abundance and spread are few, although one common approach is biological control - the introduction of specialist herbivores or pathogens from...

  8. Long-Term Effects from Bacterial Meningitis in Childhood and Adolescence on Postural Control

    Science.gov (United States)

    Petersen, Hannes; Patel, Mitesh; Ingason, Einar F.; Einarsson, Einar J.; Haraldsson, Ásgeir; Fransson, Per-Anders

    2014-01-01

    Bacterial meningitis in childhood is associated with cognitive deficiencies, sensorimotor impairments and motor dysfunction later in life. However, the long-term effects on postural control is largely unknown, e.g., whether meningitis subjects as adults fully can utilize visual information and adaptation to enhance stability. Thirty-six subjects (20 women, mean age 19.3 years) treated in childhood or adolescence for bacterial meningitis, and 25 controls (13 women, mean age 25.1 years) performed posturography with eyes open and closed under unperturbed and perturbed standing. The meningitis subjects were screened for subjective vertigo symptoms using a questionnaire, clinically tested with headshake and head thrust test, as well as their hearing was evaluated. Meningitis subjects were significantly more unstable than controls during unperturbed (p≤0.014) and perturbed standing, though while perturbed only with eyes open in anteroposterior direction (p = 0.034) whereas in lateral direction both with eyes open and closed (pMeningitis subjects had poorer adaption ability to balance perturbations especially with eyes open, and they frequently reported symptoms of unsteadiness (88% of the subjects) and dizziness (81%), which was found significantly correlated to objectively decreased stability. Out of the 36 subjects only 3 had unilateral hearing impairment. Hence, survivors of childhood bacterial meningitis may suffer long-term disorders affecting postural control, and would greatly benefit if these common late effects became generally known so treatments can be developed and applied. PMID:25405756

  9. Top-down controls on bacterial community structure: microbial network analysis of bacteria, T4-like viruses and protists

    Science.gov (United States)

    Chow, Cheryl-Emiliane T; Kim, Diane Y; Sachdeva, Rohan; Caron, David A; Fuhrman, Jed A

    2014-01-01

    Characterizing ecological relationships between viruses, bacteria and protists in the ocean are critical to understanding ecosystem function, yet these relationships are infrequently investigated together. We evaluated these relationships through microbial association network analysis of samples collected approximately monthly from March 2008 to January 2011 in the surface ocean (0–5 m) at the San Pedro Ocean Time series station. Bacterial, T4-like myoviral and protistan communities were described by Automated Ribosomal Intergenic Spacer Analysis and terminal restriction fragment length polymorphism of the gene encoding the major capsid protein (g23) and 18S ribosomal DNA, respectively. Concurrent shifts in community structure suggested similar timing of responses to environmental and biological parameters. We linked T4-like myoviral, bacterial and protistan operational taxonomic units by local similarity correlations, which were then visualized as association networks. Network links (correlations) potentially represent synergistic and antagonistic relationships such as viral lysis, grazing, competition or other interactions. We found that virus–bacteria relationships were more cross-linked than protist–bacteria relationships, suggestive of increased taxonomic specificity in virus–bacteria relationships. We also found that 80% of bacterial–protist and 74% of bacterial–viral correlations were positive, with the latter suggesting that at monthly and seasonal timescales, viruses may be following their hosts more often than controlling host abundance. PMID:24196323

  10. Biological Control of Fusarium Stalk Rot of Maize Using Bacillus spp

    Directory of Open Access Journals (Sweden)

    Joon-Hee Han

    2015-12-01

    Full Text Available Maize (Zea mays L. is an economically important crop in worldwide. While the consumption of the maize is steadily increasing, the yield is decreasing due to continuous mono-cultivation and infection of soil-borne fungal pathogens such as Fusarium species. Recently, stalk rot disease in maize, caused by F. subglutinans and F. temperatum has been reported in Korea. In this study, we isolated bacterial isolates in rhizosphere soil of maize and subsequently tested for antagonistic activities against F. subglutinans and F. temperatum. A total of 1,357 bacterial strains were isolated from rhizosphere. Among them three bacterial isolates (GC02, GC07, GC08 were selected, based on antagonistic effects against Fusarium species. The isolates GC02 and GC07 were most efficient in inhibiting the mycelium growth of the pathogens. The three isolates GC02, GC07 and GC08 were identified as Bacillus methylotrophicus, B. amyloliquefaciens and B. thuringiensis using 16S rRNA sequence analysis, respectively. GC02 and GC07 bacterial suspensions were able to suppress over 80% conidial germination of the pathogens. GC02, GC07 and GC08 were capable of producing large quantities of protease enzymes, whereas the isolates GC07 and GC08 produced cellulase enzymes. The isolates GC02 and GC07 were more efficient in phosphate solubilization and siderophore production than GC08. Analysis of disease suppression revealed that GC07 was most effective in suppressing the disease development of stalk rot. It was also found that B. methylotrophicus GC02 and B. amyloliquefaciens GC07 have an ability to inhibit the growth of other plant pathogenic fungi. This study indicated B. methylotrophicus GC02 and B. amyloliquefaciens GC07 has potential for being used for the development of a biological control agent.

  11. Biologically controlled minerals as potential indicators of life

    Science.gov (United States)

    Schwartz, D. E.; Mancinelli, R. L.; Kaneshiro, E.

    1991-01-01

    Minerals can be produced and deposited either by abiotic or biologic means. Regardless of their origin, mineral crystals reflect the environment conditions (e.g., temperature, pressure, chemical composition, and redox potential) present during crystal formation. Biologically-produced mineral crystals are grown or reworked under the control of their host organism and reflect an environment different from the abiotic environment. In addition, minerals of either biologic or abiotic origin have great longevities. For these reasons, biologically produced minerals have been proposed as biomarkers. Biomarkers are key morphological, chemical, and isotopic signatures of living systems that can be used to determine if life processes have occurred. Studies of biologically controlled minerals produced by the protist, Paramecium tetraurelia, were initiated since techniques have already been developed to culture them and isolate their crystalline material, and methods are already in place to analyze this material. Two direct crystalline phases were identified. One phase, whose chemical composition is high in Mg, was identified as struvite. The second phase, whose chemical composition is high in Ca, has not been previously found occurring naturally and may be considered a newly discovered material. Analyses are underway to determine the characteristics of these minerals in order to compare them with characteristics of these minerals in order to compare them with characteristics of minerals formed abiotically, but with the same chemical composition.

  12. Economic Benefit for Cuban Laurel Thrips Biological Control.

    Science.gov (United States)

    Shogren, C; Paine, T D

    2016-02-01

    The Cuban laurel thrips, Gynaikothrips ficorum Marchal (Thysanoptera: Phlaeothripidae), is a critical insect pest of Ficus microcarpa in California urban landscapes and production nurseries. Female thrips feed and oviposit on young Ficus leaves, causing the expanding leaves to fold or curl into a discolored leaf gall. There have been attempts to establish specialist predator natural enemies of the thrips, but no success has been reported. We resampled the same areas in 2013-2014 where we had released Montandoniola confusa (= morguesi) Streito and Matocq (Hemiptera: Anthocoridae) in southern California in 1995 but had been unable to recover individuals in 1997-1998. Thrips galls were significantly reduced in all three of the locations in the recent samples compared with the earlier samples. M. confusa was present in all locations and appears to be providing successful biological control. The value of the biological control, the difference between street trees in good foliage condition and trees with poor foliage, was $58,766,166. If thrips damage reduced the foliage to very poor condition, the value of biological control was $73,402,683. Total cost for the project was $61,830. The benefit accrued for every dollar spent on the biological control of the thrips ranged from $950, if the foliage was in poor condition, to $1,187, if the foliage was in very poor condition. The value of urban forest is often underappreciated. Economic analyses that clearly demonstrate the very substantial rates of return on investment in successful biological control in urban forests provide compelling arguments for supporting future efforts. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Evaluation of Orius species for biological control of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)

    NARCIS (Netherlands)

    Tommasini, M.G.

    2003-01-01

    Key words: Thysanoptera, Frankliniella occidentalis, Heteroptera, Orius leavigatu, Orius majusculu, Orius niger, Orius insidiosus, Biology, Diapause, Biological control.The overall aim of this research was to develop a biological control programme for F. occidentalis through the selection of

  14. Speed and Displacement Control System of Bearingless Brushless DC Motor Based on Improved Bacterial Foraging Algorithm

    Directory of Open Access Journals (Sweden)

    Diao Xiaoyan

    2016-01-01

    Full Text Available To solve the deficiencies of long optimization time and poor precision existing in conventional bacterial foraging algorithm (BFA in the process of parameter optimization, an improved bacterial foraging algorithm (IBFA is proposed and applied to speed and displacement control system of bearingless brushless DC (Bearingless BLDC motors. To begin with the fundamental principle of BFA, the proposed method is introduced and the individual intelligence is efficiently used in the process of parameter optimization, and then the working principle of bearingless BLDC motors is expounded. Finally, modeling and simulation of the speed and displacement control system of bearingless BLDC motors based on the IBFA are carried out by taking the software of MATLAB/Simulink as a platform. Simulation results show that, speed overshoot, torque ripple and rotor position oscillation are dramatically reduced, thus the proposed method has good application prospects in the field of bearingless motors.

  15. Paths and patterns: the biology and physics of swimming bacterial populations

    Science.gov (United States)

    Kessler, J. O.; Strittmatter, R. P.; Swartz, D. L.; Wiseley, D. A.; Wojciechowski, M. F.

    1995-01-01

    The velocity distribution of swimming micro-organisms depends on directional cues supplied by the environment. Directional swimming within a bounded space results in the accumulation of organisms near one or more surfaces. Gravity, gradients of chemical concentration and illumination affect the motile behaviour of individual swimmers. Concentrated populations of organisms scatter and absorb light or consume molecules, such as oxygen. When supply is one-sided, consumption creates gradients; the presence of the population alters the intensity and the symmetry of the environmental cues. Patterns of cues interact dynamically with patterns of the consumer population. In suspensions, spatial variations in the concentration of organisms are equivalent to variations of mean mass density of the fluid. When organisms accumulate in one region whilst moving away from another region, the force of gravity causes convection that translocates both organisms and dissolved substances. The geometry of the resulting concentration-convection patterns has features that are remarkably reproducible. Of interest for biology are (1) the long-range organisation achieved by organisms that do not communicate, and (2) that the entire system, consisting of fluid, cells, directional supply of consumables, boundaries and gravity, generates a dynamic that improves the organisms' habitat by enhancing transport and mixing. Velocity distributions of the bacterium Bacillus subtilis have been measured within the milieu of the spatially and temporally varying oxygen concentration which they themselves create. These distributions of swimming speed and direction are the fundamental ingredients required for a quantitative mathematical treatment of the patterns. The quantitative measurement of swimming behaviour also contributes to our understanding of aerotaxis of individual cells.

  16. Tuning the Density of Poly(ethylene glycol Chains to Control Mammalian Cell and Bacterial Attachment

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Ani

    2017-08-01

    Full Text Available Surface modification of biomaterials with polymer chains has attracted great attention because of their ability to control biointerfacial interactions such as protein adsorption, cell attachment and bacterial biofilm formation. The aim of this study was to control the immobilisation of biomolecules on silicon wafers using poly(ethylene glycol(PEG chains by a “grafting to” technique. In particular, to control the polymer chain graft density in order to capture proteins and preserve their activity in cell culture as well as find the optimal density that would totally prevent bacterial attachment. The PEG graft density was varied by changing the polymer solubility using an increasing salt concentration. The silicon substrates were initially modified with aminopropyl-triethoxysilane (APTES, where the surface density of amine groups was optimised using different concentrations. The results showed under specific conditions, the PEG density was highest with grafting under “cloud point” conditions. The modified surfaces were characterised with X-ray photoelectron spectroscopy (XPS, ellipsometry, atomic force microscopy (AFM and water contact angle measurements. In addition, all modified surfaces were tested with protein solutions and in cell (mesenchymal stem cells and MG63 osteoblast-like cells and bacterial (Pseudomonas aeruginosa attachment assays. Overall, the lowest protein adsorption was observed on the highest polymer graft density, bacterial adhesion was very low on all modified surfaces, and it can be seen that the attachment of mammalian cells gradually increased as the PEG grafting density decreased, reaching the maximum attachment at medium PEG densities. The results demonstrate that, at certain PEG surface coverages, mammalian cell attachment can be tuned with the potential to optimise their behaviour with controlled serum protein adsorption.

  17. Bacterial toxin-antitoxin gene system as containment control in yeast cells

    DEFF Research Database (Denmark)

    Kristoffersen, P.; Jensen, G. B.; Gerdes, K.

    2000-01-01

    The potential of a bacterial toxin-antitoxin gene system for use in containment control in eukaryotes was explored. The Escherichia coli relE and relB genes were expressed in the yeast Saccharomyces cerevisiae, Expression of the relE gene was highly toxic to yeast cells. However, expression...... fermentation processes in which the escape of genetically modified cells would be considered highly risky....

  18. Epigenetics and Why Biological Networks are More Controllable than Expected

    Science.gov (United States)

    Motter, Adilson

    2013-03-01

    A fundamental property of networks is that perturbations to one node can affect other nodes, potentially causing the entire system to change behavior or fail. In this talk, I will show that it is possible to exploit this same principle to control network behavior. This approach takes advantage of the nonlinear dynamics inherent to real networks, and allows bringing the system to a desired target state even when this state is not directly accessible or the linear counterpart is not controllable. Applications show that this framework permits both reprogramming a network to a desired task as well as rescuing networks from the brink of failure, which I will illustrate through various biological problems. I will also briefly review the progress our group has made over the past 5 years on related control of complex networks in non-biological domains.

  19. Application of a microcomputer-based system to control and monitor bacterial growth.

    Science.gov (United States)

    Titus, J A; Luli, G W; Dekleva, M L; Strohl, W R

    1984-02-01

    A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO(2), and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations.

  20. A theoretical approach on controlling agricultural pest by biological controls.

    Science.gov (United States)

    Mondal, Prasanta Kumar; Jana, Soovoojeet; Kar, T K

    2014-03-01

    In this paper we propose and analyze a prey-predator type dynamical system for pest control where prey population is treated as the pest. We consider two classes for the pest namely susceptible pest and infected pest and the predator population is the natural enemy of the pest. We also consider average delay for both the predation rate i.e. predation to the susceptible pest and infected pest. Considering a subsystem of original system in the absence of infection, we analyze the existence of all possible non-negative equilibria and their stability criteria for both the subsystem as well as the original system. We present the conditions for transcritical bifurcation and Hopf bifurcation in the disease free system. The theoretical evaluations are demonstrated through numerical simulations.

  1. Thresholds for HLB vector control in infected commercial citrus and compatibility with biological control

    OpenAIRE

    Monzo, C.; Hendricks, K.; Roberts, P.; Stansly, P. A.

    2014-01-01

    Control of the HLB vector, Diaphorina citri Kuwayama, is considered a basic component for management this disease, even in a high HLB incidence scenario. Such control is mostly chemically oriented. However, over use of insecticides would increase costs and be incompatible with biological control. Establishment of economic thresholds for psyllid control under different price scenarios could optimize returns on investment.

  2. Quality control of X-ray irradiator by biological markers

    International Nuclear Information System (INIS)

    Miura, Miwa; Lukmanul Hakkim, F.; Yoshida, Masahiro; Matsuda, Naoki; Morita, Naoko

    2011-01-01

    The exposure of animals or cultured cells to radiation is the essential and common step in experimental researches to elucidate biological effects of radiation. When an X-ray generator is used as a radiation source, physical parameters including dose, dose rate, and the energy spectrum of X-ray play crucial roles in biological outcome. Therefore, those parameters are the important points to be checked in quality control and to be carefully considered in advance to the irradiation to obtain the accurate and reproductive results. Here we measured radiation dose emitted from the X-ray irradiator for research purposes by using clonogenic survival of cultured mammalian cells as a biological marker in parallel with physical dosimetry. The results drawn from both methods exhibited good consistency in the dose distribution on the irradiation stage. Furthermore, the close relationship was observed between cell survival and the photon energy spectrum by using different filter components. These results suggest that biological dosimetry is applicable to quality control of X-ray irradiator in adjunct to physical dosimetry and that it possibly helps better understanding of the optimal irradiating condition by X-ray users in life-science field. (author)

  3. Biological control and invading freshwater snails. A case study.

    Science.gov (United States)

    Pointier, J P; Augustin, D

    1999-12-01

    Introductions of four species of freshwater snails occurred between 1972 and 1996 onto Guadeloupe Island. Two of them, Melanoides tuberculata and Marisa cornuarietis, were subsequently used as biological control agents against Biomphalaria glabrata, the snail intermediate host of intestinal schistosomiasis. In 1996, a general survey was carried out in 134 sites which had already been investigated in 1972. The total number of mollusc species had increased from 19 to 21. Site numbers housing B. glabrata and two other species had strongly declined. This decline may be mainly attributed to a competitive displacement by M. tuberculata and M. cornuarietis as illustrated by several biological control programmes. There were no changes in the remainder of the malacological fauna.

  4. Design control considerations for biologic-device combination products.

    Science.gov (United States)

    Anderson, Dave; Liu, Roger; Anand Subramony, J; Cammack, Jon

    2017-03-01

    Combination products are therapeutic and diagnostic medical products that combine drugs, devices, and/or biological products with one another. Historically, biologics development involved identifying efficacious doses administered to patients intravenously or perhaps by a syringe. Until fairly recently, there has been limited focus on developing an accompanying medical device, such as a prefilled syringe or auto-injector, to enable easy and more efficient delivery. For the last several years, and looking forward, where there may be little to distinguish biologics medicines with relatively similar efficacy profiles, the biotechnology market is beginning to differentiate products by patient-focused, biologic-device based combination products. As innovative as biologic-device combination products are, they can pose considerable development, regulatory, and commercialization challenges due to unique physicochemical properties and special clinical considerations (e.g., dosing volumes, frequency, co-medications, etc.) of the biologic medicine. A biologic-device combination product is a marriage between two partners with "cultural differences," so to speak. There are clear differences in the development, review, and commercialization processes of the biologic and the device. When these two cultures come together in a combination product, developers and reviewers must find ways to address the design controls and risk management processes of both the biologic and device, and knit them into a single entity with supporting product approval documentation. Moreover, digital medicine and connected health trends are pushing the boundaries of combination product development and regulations even further. Despite an admirable cooperation between industry and FDA in recent years, unique product configurations and design features have resulted in review challenges. These challenges have prompted agency reviewers to modernize consultation processes, while at the same time, promoting

  5. Controlled polymer synthesis--from biomimicry towards synthetic biology.

    Science.gov (United States)

    Pasparakis, George; Krasnogor, Natalio; Cronin, Leroy; Davis, Benjamin G; Alexander, Cameron

    2010-01-01

    The controlled assembly of synthetic polymer structures is now possible with an unprecedented range of functional groups and molecular architectures. In this critical review we consider how the ability to create artificial materials over lengthscales ranging from a few nm to several microns is generating systems that not only begin to mimic those in nature but also may lead to exciting applications in synthetic biology (139 references).

  6. Assessing Probabilistic Risk Assessment Approaches for Insect Biological Control Introductions

    OpenAIRE

    Kaufman, Leyla V.; Wright, Mark G.

    2017-01-01

    The introduction of biological control agents to new environments requires host specificity tests to estimate potential non-target impacts of a prospective agent. Currently, the approach is conservative, and is based on physiological host ranges determined under captive rearing conditions, without consideration for ecological factors that may influence realized host range. We use historical data and current field data from introduced parasitoids that attack an endemic Lepidoptera species in H...

  7. ECOLOGY OF PANTOEA AGGLOMERANS 2066-7 STRAIN: A BIOLOGICAL CONTROL OF BACTERIA ONION DISEASES

    Directory of Open Access Journals (Sweden)

    Soumia Sadik

    2016-06-01

    Full Text Available The growth response of the biocontrol agent Pantoea agglomerans 2066-7 to change in water activity (aw, temperature, and pH was determined in vitro in basic medium. The minimum temperature at which 2066-7 was able to grow was 7°C, and the growth of 2066-7 did not change at varying pH levels (4–10.34. The best growth was obtained at a water activity of 0.98 in all media modified with the four solutes (glucose, glycerol, NaCl and polyethylene glycol. The solute used to reduce water activity had a great influence on bacterial growth, especially at unfavorable conditions (low temperature. This study has defined the range of environmental conditions (aw, pH, and temperature over which the bacteria may be developed for biological control of plant diseases.

  8. Biologically-Inspired Control Architecture for Musical Performance Robots

    Directory of Open Access Journals (Sweden)

    Jorge Solis

    2014-10-01

    Full Text Available At Waseda University, since 1990, the authors have been developing anthropomorphic musical performance robots as a means for understanding human control, introducing novel ways of interaction between musical partners and robots, and proposing applications for humanoid robots. In this paper, the design of a biologically-inspired control architecture for both an anthropomorphic flutist robot and a saxophone playing robot are described. As for the flutist robot, the authors have focused on implementing an auditory feedback system to improve the calibration procedure for the robot in order to play all the notes correctly during a performance. In particular, the proposed auditory feedback system is composed of three main modules: an Expressive Music Generator, a Feed Forward Air Pressure Control System and a Pitch Evaluation System. As for the saxophone-playing robot, a pressure-pitch controller (based on the feedback error learning to improve the sound produced by the robot during a musical performance was proposed and implemented. In both cases studied, a set of experiments are described to verify the improvements achieved while considering biologically-inspired control approaches.

  9. Self-Organized Biological Dynamics and Nonlinear Control

    Science.gov (United States)

    Walleczek, Jan

    2006-04-01

    The frontiers and challenges of biodynamics research Jan Walleczek; Part I. Nonlinear Dynamics in Biology and Response to Stimuli: 1. External signals and internal oscillation dynamics - principal aspects and response of stimulated rhythmic processes Friedemann Kaiser; 2. Nonlinear dynamics in biochemical and biophysical systems: from enzyme kinetics to epilepsy Raima Larter, Robert Worth and Brent Speelman; 3. Fractal mechanisms in neural control: human heartbeat and gait dynamics in health and disease Chung-Kang Peng, Jeffrey M. Hausdorff and Ary L. Goldberger; 4. Self-organising dynamics in human coordination and perception Mingzhou Ding, Yanqing Chen, J. A. Scott Kelso and Betty Tuller; 5. Signal processing in biochemical reaction networks Adam P. Arkin; Part II. Nonlinear Sensitivity of Biological Systems to Electromagnetic Stimuli: 6. Electrical signal detection and noise in systems with long-range coherence Paul C. Gailey; 7. Oscillatory signals in migrating neutrophils: effects of time-varying chemical and electrical fields Howard R. Petty; 8. Enzyme kinetics and nonlinear biochemical amplification in response to static and oscillating magnetic fields Jan Walleczek and Clemens F. Eichwald; 9. Magnetic field sensitivity in the hippocampus Stefan Engström, Suzanne Bawin and W. Ross Adey; Part III. Stochastic Noise-Induced Dynamics and Transport in Biological Systems: 10. Stochastic resonance: looking forward Frank Moss; 11. Stochastic resonance and small-amplitude signal transduction in voltage-gated ion channels Sergey M. Bezrukov and Igor Vodyanoy; 12. Ratchets, rectifiers and demons: the constructive role of noise in free energy and signal transduction R. Dean Astumian; 13. Cellular transduction of periodic and stochastic energy signals by electroconformational coupling Tian Y. Tsong; Part IV. Nonlinear Control of Biological and Other Excitable Systems: 14. Controlling chaos in dynamical systems Kenneth Showalter; 15. Electromagnetic fields and biological

  10. Adaptive Fuzzy-Lyapunov Controller Using Biologically Inspired Swarm Intelligence

    Directory of Open Access Journals (Sweden)

    Alejandro Carrasco Elizalde

    2008-01-01

    Full Text Available The collective behaviour of swarms produces smarter actions than those achieved by a single individual. Colonies of ants, flocks of birds and fish schools are examples of swarms interacting with their environment to achieve a common goal. This cooperative biological intelligence is the inspiration for an adaptive fuzzy controller developed in this paper. Swarm intelligence is used to adjust the parameters of the membership functions used in the adaptive fuzzy controller. The rules of the controller are designed using a computing-with-words approach called Fuzzy-Lyapunov synthesis to improve the stability and robustness of an adaptive fuzzy controller. Computing-with-words provides a powerful tool to manipulate numbers and symbols, like words in a natural language.

  11. Defense reactions of bean genotypes to bacterial pathogens in controlled conditions

    Science.gov (United States)

    Uysal, B.; Bastas, K. K.

    2018-03-01

    This study was focused on the role of antioxidant enzymes and total protein in imparting resistance against common bacterial blight caused by Xanthomonas axonopodis pv. phaseoli (Xap) and halo blight caused by Pseudomonas syringae pv. phaseolicola (Psp) in bean. Activities of Ascorbate peroxidase (APX), Catalase (CAT) and total protein were studied in resistant and susceptible bean genotypes. Five-day-old seedlings were inoculated with a bacterial suspension (108 CFU ml-1) and harvested at different time intervals (0, 12, 24 and 36 up to 72 h) under controlled growing conditions and assayed for antioxidant enzymes and total protein. Temporal increase of CAT, APX enzymes activities showed maximum activity at 12 h after both pathogens inoculation (hpi) in resistant cultivar, whereas in susceptible it increased at 72 h after both pathogens inoculation for CAT and 12, 24 h for APX enzymes. Maximum total protein activities were observed at 12 h and 24 h respectively after Xap, Psp inoculation (hpi) in resistant and maximum activities were observed at 24 h and 72 h respectively after Xap, Psp inoculation (hpi) in susceptible. Increase of antioxidant enzyme and total protein activities might be an important component in the defense strategy of resistance and susceptible bean genotypes against the bacterial infection. These findings suggest that disease protection is proportional to the amount of enhanced CAT, APX enzyme and total protein activity.

  12. Plant Growth Promoting Bacteria Associated with Langsdorffia hypogaea-Rhizosphere-Host Biological Interface: A Neglected Model of Bacterial Prospection

    Science.gov (United States)

    Felestrino, Érica B.; Santiago, Iara F.; Freitas, Luana da Silva; Rosa, Luiz H.; Ribeiro, Sérvio P.; Moreira, Leandro M.

    2017-01-01

    Soil is a habitat where plant roots and microorganisms interact. In the region of the Brazilian Iron Quadrangle (IQ), studies involving the interaction between microbiota and plants have been neglected. Even more neglected are the studies involving the holoparasite plant Langsdorffia hypogaea Mart. (Balanophoraceae). The geomorphological peculiarities of IQ soil, rich in iron ore, as well as the model of interaction between L. hypogaea, its hosts and the soil provide a unique niche that acts as selective pressure to the evolution of plant growth-promoting bacteria (PGPB). The aim of this study was to prospect the bacterial microbiota of holoparasitic plant L. hypogaea, its plant host and corresponding rhizosphere of IQ soil, and to analyze the potential of these isolates as PGPB. We obtained samples of 11 individuals of L. hypogaea containing fragments of host and rhizosphere remnants, resulting in 81 isolates associated with Firmicutes and Proteobacteria phyla. The ability to produce siderophores, hydrocyanic acid (HCN), indole-3-acetic acid (IAA), nitrogen (N2) fixation, hydrolytic enzymes secretion and inhibition of enteropathogens, and phytopathogens were evaluated. Of the total isolates, 62, 86, and 93% produced, respectively, siderophores, IAA, and were able to fix N2. In addition, 27 and 20% of isolates inhibited the growth of enteropathogens and phytopathogens, respectively, and 58% were able to produce at least one hydrolytic activity investigated. The high number of isolates that produce siderophores and indole-3-acetic acid suggests that this microbiota may be important for adaptation of plants to IQ. The results demonstrate for the first time the biological importance of Brazilian IQ species as reservoirs of specific microbiotas that might be used as PGPB on agricultural land or antropized soils that needs to be reforested. PMID:28239369

  13. Biopesticides: An option for the biological pest control

    Directory of Open Access Journals (Sweden)

    Eusebio Nava Pérez

    2012-09-01

    Full Text Available The indiscriminate use of synthetic pesticides and the problems that its cause to human health, agriculture and the environment is comment, this paper also present general aspects about of biopesticides, and their uses in the biological pest control. By the nature these can be safely used in a sustainable agriculture. An example is the use of botanical pesticides whose active ingredient are the terpenes, alkaloids and phenolics, these have insecticide effects for many agriculture pests; also its are less expensive, are biodegradable and safe for humans and the environment, however havelittle residuality. Microbial pesticides are being introduced successfully to pests control in important crops such as; coffee, sugar cane, beans and corn. These products contain bacteria, fungi, viruses or nematodes. However, few entomopathogenic agents have been developed as effective biocontrol agents, one of them is the bacterium Bacillus thuringiensis (Berlinier for control of armyworm Spodoptera frugiperda (J.E Smith covering about 74% of the market,fungus 10% , viruses 5% and 11% others. Other upstanding case is the use of the fungus Beauveria bassiana (Balsamoagainst bean weevil Acanthoscelides obtectus (Say. Biopesticides have shown that when are used properly in the biological pest control its favor the practice of a sustainable agriculture, with less dependence of chemical insecticides.

  14. Synthetic biology and regulatory networks: where metabolic systems biology meets control engineering.

    Science.gov (United States)

    He, Fei; Murabito, Ettore; Westerhoff, Hans V

    2016-04-01

    Metabolic pathways can be engineered to maximize the synthesis of various products of interest. With the advent of computational systems biology, this endeavour is usually carried out through in silico theoretical studies with the aim to guide and complement further in vitro and in vivo experimental efforts. Clearly, what counts is the result in vivo, not only in terms of maximal productivity but also robustness against environmental perturbations. Engineering an organism towards an increased production flux, however, often compromises that robustness. In this contribution, we review and investigate how various analytical approaches used in metabolic engineering and synthetic biology are related to concepts developed by systems and control engineering. While trade-offs between production optimality and cellular robustness have already been studied diagnostically and statically, the dynamics also matter. Integration of the dynamic design aspects of control engineering with the more diagnostic aspects of metabolic, hierarchical control and regulation analysis is leading to the new, conceptual and operational framework required for the design of robust and productive dynamic pathways. © 2016 The Author(s).

  15. Biological Control to Protect Watermelon Blossoms and Seed from Infection by Acidovorax avenae subsp. citrulli.

    Science.gov (United States)

    Fessehaie, A; Walcott, R R

    2005-04-01

    ABSTRACT The efficacy of biological control seed treatments with Pseudomonas fluorescens (A506), Acidovorax avenae subsp. avenae (AAA 99-2), and an unidentified gram-positive bacterium recovered from watermelon seed (WS-1) was evaluated for the management of bacterial fruit blotch (BFB) of watermelon. In growth chamber and greenhouse experiments, seed treated with AAA 99-2 displayed superior disease suppression, reducing BFB transmission by 96.5%. AAA 99-2, P. fluorescens A506, and Kocide also suppressed the epiphytic growth of A. avenae subsp. citrulli when applied to attached watermelon blossoms 5 h prior to inoculation. Watermelon blossom protection reduced seed infestation by A. avenae subsp. citrulli. From blossoms treated with 0.1 M phosphate buffered saline (PBS), 63% of the resulting seed lots were infested with A. avenae subsp. citrulli. In contrast, for blossoms protected with WS-1, Kocide, P. fluorescens A506, and AAA 99-2, the proportion of infested seed lots were 48.3, 21.1, 24.1, and 13.8%, respectively. The effect of blossom treatments on seed lot infestation was statistically significant (P = 0.001) but WS-1 was not significantly different from PBS. These findings suggest that blossom protection with biological control agents could be a feasible option for managing BFB.

  16. The physicochemical process of bacterial attachment to abiotic surfaces: Challenges for mechanistic studies, predictability and the development of control strategies.

    Science.gov (United States)

    Wang, Yi; Lee, Sui Mae; Dykes, Gary

    2015-01-01

    Bacterial attachment to abiotic surfaces can be explained as a physicochemical process. Mechanisms of the process have been widely studied but are not yet well understood due to their complexity. Physicochemical processes can be influenced by various interactions and factors in attachment systems, including, but not limited to, hydrophobic interactions, electrostatic interactions and substratum surface roughness. Mechanistic models and control strategies for bacterial attachment to abiotic surfaces have been established based on the current understanding of the attachment process and the interactions involved. Due to a lack of process control and standardization in the methodologies used to study the mechanisms of bacterial attachment, however, various challenges are apparent in the development of models and control strategies. In this review, the physicochemical mechanisms, interactions and factors affecting the process of bacterial attachment to abiotic surfaces are described. Mechanistic models established based on these parameters are discussed in terms of their limitations. Currently employed methods to study these parameters and bacterial attachment are critically compared. The roles of these parameters in the development of control strategies for bacterial attachment are reviewed, and the challenges that arise in developing mechanistic models and control strategies are assessed.

  17. Bacterial Community Succession During in situ Uranium Bioremediation: Spatial Similarities Along Controlled Flow Paths

    International Nuclear Information System (INIS)

    Hwang, Chiachi; Wu, Weimin; Gentry, Terry J.; Carley, Jack; Corbin, Gail A.; Carroll, Sue L.; Watson, David B.; Jardine, Phil M.; Zhou, Jizhong; Criddle, Craig S.; Fields, Matthew W.

    2009-01-01

    Bacterial community succession was investigated in a field-scale subsurface reactor formed by a series of wells that received weekly ethanol additions to re-circulating groundwater. Ethanol additions stimulated denitrification, metal reduction, sulfate reduction, and U(VI) reduction to sparingly soluble U(IV). Clone libraries of SSU rRNA gene sequences from groundwater samples enabled tracking of spatial and temporal changes over a 1.5 y period. Analyses showed that the communities changed in a manner consistent with geochemical variations that occurred along temporal and spatial scales. Canonical correspondence analysis revealed that the levels of nitrate, uranium, sulfide, sulfate, and ethanol strongly correlated with particular bacterial populations. As sulfate and U(VI) levels declined, sequences representative of sulfate-reducers and metal-reducers were detected at high levels. Ultimately, sequences associated with sulfate-reducing populations predominated, and sulfate levels declined as U(VI) remained at low levels. When engineering controls were compared to the population variation via canonical ordination, changes could be related to dissolved oxygen control and ethanol addition. The data also indicated that the indigenous populations responded differently to stimulation for bio-reduction; however, the two bio-stimulated communities became more similar after different transitions in an idiosyncratic manner. The strong associations between particular environmental variables and certain populations provide insight into the establishment of practical and successful remediation strategies in radionuclide-contaminated environments with respect to engineering controls and microbial ecology.

  18. Control of bacterial biofilm growth on surfaces by nanostructural mechanics and geometry

    International Nuclear Information System (INIS)

    Epstein, A K; Hochbaum, A I; Kim, Philseok; Aizenberg, J

    2011-01-01

    Surface-associated communities of bacteria, called biofilms, pervade natural and anthropogenic environments. Mature biofilms are resistant to a wide range of antimicrobial treatments and therefore pose persistent pathogenic threats. The use of surface chemistry to inhibit biofilm growth has been found to only transiently affect initial attachment. In this work, we investigate the tunable effects of physical surface properties, including high-aspect-ratio (HAR) surface nanostructure arrays recently reported to induce long-range spontaneous spatial patterning of bacteria on the surface. The functional parameters and length scale regimes that control such artificial patterning for the rod-shaped pathogenic species Pseudomonas aeruginosa are elucidated through a combinatorial approach. We further report a crossover regime of biofilm growth on a HAR nanostructured surface versus the nanostructure effective stiffness. When the 'softness' of the hair-like nanoarray is increased beyond a threshold value, biofilm growth is inhibited as compared to a flat control surface. This result is consistent with the mechanoselective adhesion of bacteria to surfaces. Therefore by combining nanoarray-induced bacterial patterning and modulating the effective stiffness of the nanoarray—thus mimicking an extremely compliant flat surface—bacterial mechanoselective adhesion can be exploited to control and inhibit biofilm growth.

  19. Bacterial Community Succession During in situ Uranium Bioremediation: Spatial Similarities Along Controlled Flow Paths

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Chiachi; Wu, Weimin; Gentry, Terry J.; Carley, Jack; Corbin, Gail A.; Carroll, Sue L.; Watson, David B.; Jardine, Phil M.; Zhou, Jizhong; Criddle, Craig S.; Fields, Matthew W.

    2009-05-22

    Bacterial community succession was investigated in a field-scale subsurface reactor formed by a series of wells that received weekly ethanol additions to re-circulating groundwater. Ethanol additions stimulated denitrification, metal reduction, sulfate reduction, and U(VI) reduction to sparingly soluble U(IV). Clone libraries of SSU rRNA gene sequences from groundwater samples enabled tracking of spatial and temporal changes over a 1.5 y period. Analyses showed that the communities changed in a manner consistent with geochemical variations that occurred along temporal and spatial scales. Canonical correspondence analysis revealed that the levels of nitrate, uranium, sulfide, sulfate, and ethanol strongly correlated with particular bacterial populations. As sulfate and U(VI) levels declined, sequences representative of sulfate-reducers and metal-reducers were detected at high levels. Ultimately, sequences associated with sulfate-reducing populations predominated, and sulfate levels declined as U(VI) remained at low levels. When engineering controls were compared to the population variation via canonical ordination, changes could be related to dissolved oxygen control and ethanol addition. The data also indicated that the indigenous populations responded differently to stimulation for bio-reduction; however, the two bio-stimulated communities became more similar after different transitions in an idiosyncratic manner. The strong associations between particular environmental variables and certain populations provide insight into the establishment of practical and successful remediation strategies in radionuclide-contaminated environments with respect to engineering controls and microbial ecology.

  20. Multiple levels of epigenetic control for bone biology and pathology.

    Science.gov (United States)

    Montecino, Martin; Stein, Gary; Stein, Janet; Zaidi, Kaleem; Aguilar, Rodrigo

    2015-12-01

    Multiple dimensions of epigenetic control contribute to regulation of gene expression that governs bone biology and pathology. Once confined to DNA methylation and a limited number of post-translational modifications of histone proteins, the definition of epigenetic mechanisms is expanding to include contributions of non-coding RNAs and mitotic bookmarking, a mechanism for retaining phenotype identity during cell proliferation. Together these different levels of epigenetic control of physiological processes and their perturbations that are associated with compromised gene expression during the onset and progression of disease, have contributed to an unprecedented understanding of the activities (operation) of the genomic landscape. Here, we address general concepts that explain the contribution of epigenetic control to the dynamic regulation of gene expression during eukaryotic transcription. This article is part of a Special Issue entitled Epigenetics and Bone. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Limulus amebocyte lysate technique (LAL) for bacterial endotoxin control in radiodiagnosis agents (kits) and radioisotopes

    International Nuclear Information System (INIS)

    Morote, M.; Robles, A.; Ramos, B.; Otero, M.

    1997-01-01

    A procedure based on a fast technique of LAL individual kits has been devised to control bacterial endotoxins in radiodiagnosis agents (RDA): HEMTEC, DEIDA, PPI, AMD, GHCa, RENTEC, DMSA, MAA, TSC, HERTEC, DTPA, BRATEC and EDTMP as well as in radioisotopes I-131 and Tc99m. The procedures begins with the determination of the following values, injection volume (IV), endotoxin limits (EL), maximum valid dilution (MVD), total mass (TM), reconstitution volume (RV), concentration (mg/ml), and final dilution (FD). Subsequently, a procedure is carried out to conduct an 'in vitro' control of the radiodiagnosis agents and radioisotopes with LAL individual kits; the procedures includes: reconstitution of the sample to be controlled, dilution, inoculation of the diluted sample in LAL tubes and incubation at 37 o C for an hour. Finally, results are interpreted through the observation of gel formation or not in LAL tubes

  2. A Biomechanical Comparison of Proportional Electromyography Control to Biological Torque Control Using a Powered Hip Exoskeleton

    Directory of Open Access Journals (Sweden)

    Aaron J. Young

    2017-06-01

    Full Text Available BackgroundDespite a large increase in robotic exoskeleton research, there are few studies that have examined human performance with different control strategies on the same exoskeleton device. Direct comparison studies are needed to determine how users respond to different types of control. The purpose of this study was to compare user performance using a robotic hip exoskeleton with two different controllers: a controller that targeted a biological hip torque profile and a proportional myoelectric controller.MethodsWe tested both control approaches on 10 able-bodied subjects using a pneumatically powered hip exoskeleton. The state machine controller targeted a biological hip torque profile. The myoelectric controller used electromyography (EMG of lower limb muscles to produce a proportional control signal for the hip exoskeleton. Each subject performed two 30-min exoskeleton walking trials (1.0 m/s using each controller and a 10-min trial with the exoskeleton unpowered. During each trial, we measured subjects’ metabolic cost of walking, lower limb EMG profiles, and joint kinematics and kinetics (torques and powers using a force treadmill and motion capture.ResultsCompared to unassisted walking in the exoskeleton, myoelectric control significantly reduced metabolic cost by 13% (p = 0.005 and biological hip torque control reduced metabolic cost by 7% (p = 0.261. Subjects reduced muscle activity relative to the unpowered condition for a greater number of lower limb muscles using myoelectric control compared to the biological hip torque control. More subjects subjectively preferred the myoelectric controller to the biological hip torque control.ConclusionMyoelectric control had more advantages (metabolic cost and muscle activity reduction compared to a controller that targeted a biological torque profile for walking with a robotic hip exoskeleton. However, these results were obtained with a single exoskeleton device with specific

  3. A Biomechanical Comparison of Proportional Electromyography Control to Biological Torque Control Using a Powered Hip Exoskeleton.

    Science.gov (United States)

    Young, Aaron J; Gannon, Hannah; Ferris, Daniel P

    2017-01-01

    Despite a large increase in robotic exoskeleton research, there are few studies that have examined human performance with different control strategies on the same exoskeleton device. Direct comparison studies are needed to determine how users respond to different types of control. The purpose of this study was to compare user performance using a robotic hip exoskeleton with two different controllers: a controller that targeted a biological hip torque profile and a proportional myoelectric controller. We tested both control approaches on 10 able-bodied subjects using a pneumatically powered hip exoskeleton. The state machine controller targeted a biological hip torque profile. The myoelectric controller used electromyography (EMG) of lower limb muscles to produce a proportional control signal for the hip exoskeleton. Each subject performed two 30-min exoskeleton walking trials (1.0 m/s) using each controller and a 10-min trial with the exoskeleton unpowered. During each trial, we measured subjects' metabolic cost of walking, lower limb EMG profiles, and joint kinematics and kinetics (torques and powers) using a force treadmill and motion capture. Compared to unassisted walking in the exoskeleton, myoelectric control significantly reduced metabolic cost by 13% ( p  = 0.005) and biological hip torque control reduced metabolic cost by 7% ( p  = 0.261). Subjects reduced muscle activity relative to the unpowered condition for a greater number of lower limb muscles using myoelectric control compared to the biological hip torque control. More subjects subjectively preferred the myoelectric controller to the biological hip torque control. Myoelectric control had more advantages (metabolic cost and muscle activity reduction) compared to a controller that targeted a biological torque profile for walking with a robotic hip exoskeleton. However, these results were obtained with a single exoskeleton device with specific control configurations while level walking at a

  4. Bacterial Genome Editing Strategy for Control of Transcription and Protein Stability

    DEFF Research Database (Denmark)

    Lauritsen, Ida; Martinez, Virginia; Ronda, Carlotta

    2018-01-01

    In molecular biology and cell factory engineering, tools that enable control of protein production and stability are highly important. Here, we describe protocols for tagging genes in Escherichia coli allowing for inducible degradation and transcriptional control of any soluble protein of interest....... The underlying molecular biology is based on the two cross-kingdom tools CRISPRi and the N-end rule for protein degradation. Genome editing is performed with the CRMAGE technology and randomization of the translational initiation region minimizes the polar effects of tag insertion. The approach has previously...... been applied for targeting proteins originating from essential operon-located genes and has potential to serve as a universal synthetic biology tool....

  5. Biological Efficacy of Herbicides for Weed Control in Noncropped Areas

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2009-01-01

    Full Text Available An increasing problem facing agricultural producers is the invasion of weeds, perennial in particular, so that implementation of industrial technologies is impossible without their highly efficient and rational control. For the purpose of studying efficient herbicides for weed control in noncropped areas (stubbles, a biological study of five total systemic herbicides was conducted in areas under natural weed infestation and pressure from othersurrounding weeds at the Institute of Forage Crops in Pleven in 2005-2007. The trials were carried out in field conditions using the block method with plot size of 20 m². Treatment was conducted at the predominant stage of budding of perennial dicotyledonous weeds and earing of monocotyledonous weeds. Herbicidal efficacy was recorded on the EWRS 9-score scale (0-100% killed weeds = score 9-1. It was found that treatment of noncropped areas (stubbles with the total systemic herbicides Touchdown System 4 (360 g/l glyphosate; Cosmic (360 g/l glyphosate; Roundup Plus (441 g/l glyphosate potassium salt; Leon 36 SL (360 g/l glyphosate and Glyphos Super 45 SL (450 g/l glyphosate was highly efficient, so that it was a successful element of a strategy for controlling weeds of different biological groups, and was especially effective against perennial weeds.

  6. Control of the cassava mealybug in Africa: lessons from a biological ...

    African Journals Online (AJOL)

    Control of the cassava mealybug in Africa: lessons from a biological control project. ... Such studies are needed in order to attribute the observed effects to various causes and to advance the science of biological control. ( 4) It is concluded that biological control is the basis ofiPM but cannot usually be manipulated by the ...

  7. 75 FR 64984 - Availability of an Environmental Assessment for a Biological Control Agent for Hawkweeds

    Science.gov (United States)

    2010-10-21

    ... hawkweed gall wasp, Aulacidea subterminalis, into the continental United States as a biological control... United States for the biological control of hawkweeds (Hieracium pilosella, H. aurantiacum, H... control, and the use of biological control organisms. The use of herbicides, while effective, is limited...

  8. Evaluation of bacteria for biological control of early blightdisease of ...

    African Journals Online (AJOL)

    Twenty three bacterial isolates were subjected to a whole plant test to investigate their ability to protect the tomato plant against early blight disease. In whole plant tests, 0.5 x 108 cfu/ml bacterial suspension was sprayed and one day later, A. solani spores suspension were applied on tomato seedlings and plants were ...

  9. Using biological control research in the classroom to promote scientific inquiry and literacy

    Science.gov (United States)

    Many scientists who research biological control also teach at universities or more informally through cooperative outreach. The purpose of this paper is to review biological control activities for the classroom in four refereed journals, The American Biology Teacher, Journal of Biological Education...

  10. Asymmetric positive feedback loops reliably control biological responses.

    Science.gov (United States)

    Ratushny, Alexander V; Saleem, Ramsey A; Sitko, Katherine; Ramsey, Stephen A; Aitchison, John D

    2012-04-24

    Positive feedback is a common mechanism enabling biological systems to respond to stimuli in a switch-like manner. Such systems are often characterized by the requisite formation of a heterodimer where only one of the pair is subject to feedback. This ASymmetric Self-UpREgulation (ASSURE) motif is central to many biological systems, including cholesterol homeostasis (LXRα/RXRα), adipocyte differentiation (PPARγ/RXRα), development and differentiation (RAR/RXR), myogenesis (MyoD/E12) and cellular antiviral defense (IRF3/IRF7). To understand why this motif is so prevalent, we examined its properties in an evolutionarily conserved transcriptional regulatory network in yeast (Oaf1p/Pip2p). We demonstrate that the asymmetry in positive feedback confers a competitive advantage and allows the system to robustly increase its responsiveness while precisely tuning the response to a consistent level in the presence of varying stimuli. This study reveals evolutionary advantages for the ASSURE motif, and mechanisms for control, that are relevant to pharmacologic intervention and synthetic biology applications.

  11. Suppressive composts from organic wastes as agents of biological control of fusariosis in Tatartan Republic (Russia)

    Science.gov (United States)

    Gumerova, Raushaniya; Galitskaya, Polina; Beru, Franchesca; Selivanovskaya, Svetlana

    2015-04-01

    Plant diseases are one of the seriously limiting factors of agriculture efficiency around the world. Diseases caused by fungi are the major threat to plants. Crop protection in modern agriculture heavily depends on chemical fungicides. Disadvantages of chemical pesticides soon became apparent as damage to the environment and a hazard to human health. In this regard use of biopesticides becomes an attractive alternative method of plant protection. For biological control of fungal plant diseases, separate bacterial or fungal strains as well as their communities can be used. Biopreparations must consist of microbes that are typical for local climate and soil conditions and therefore are able to survive in environments for a long time. Another option of plant pests' biological control is implementation of suppressive composts made of agricultural or other organic wastes. These composts can not only prevent the development of plant diseases, but also improve the soil fertility. The objective of this work was estimation of potential of composts and strains isolated from these composts as means for biological control of fusariosis that is one of the most widespread plant soil born disease. The composts were made up of the commonly produced agricultural wastes produced in Tatarstan Republic (Russia). Fusarium oxysporum f. sp. radicis-lycopersici was used as a model phytopathogen. Ten types of organic waste (Goat manure (GM), Chicken dung (CD), Chicken dung with straw addition (CS), Rabbit dung (RD), Cow manure (CM), Rerotting pork manure (RPM), Fresh pork manure (FPM), Pork manure with sawdust and straw (PMS), the remains of plants and leaves (PL), the vegetable waste (VW) were sampled in the big farms situated in Tatarstan Republic which is one of the main agricultural regions of Russia. The initial wastes were composted for 150 days. Further, the following characteristics of the composts were assessed: pH, electro conductivity, TOC, DOC, Ntot. On petri dishes with meat

  12. Biologically inspired autonomous structural materials with controlled toughening and healing

    Science.gov (United States)

    Garcia, Michael E.; Sodano, Henry A.

    2010-04-01

    The field of structural health monitoring (SHM) has made significant contributions in the field of prognosis and damage detection in the past decade. The advantageous use of this technology has not been integrated into operational structures to prevent damage from propagating or to heal injured regions under real time loading conditions. Rather, current systems relay this information to a central processor or human operator, who then determines a course of action such as altering the mission or scheduling repair maintenance. Biological systems exhibit advanced sensory and healing traits that can be applied to the design of material systems. For instance, bone is the major structural component in vertebrates; however, unlike modern structural materials, bone has many properties that make it effective for arresting the propagation of cracks and subsequent healing of the fractured area. The foremost goal for the development of future adaptive structures is to mimic biological systems, similar to bone, such that the material system can detect damage and deploy defensive traits to impede damage from propagating, thus preventing catastrophic failure while in operation. After sensing and stalling the propagation of damage, the structure must then be repaired autonomously using self healing mechanisms motivated by biological systems. Here a novel autonomous system is developed using shape memory polymers (SMPs), that employs an optical fiber network as both a damage detection sensor and a network to deliver stimulus to the damage site initiating adaptation and healing. In the presence of damage the fiber optic fractures allowing a high power laser diode to deposit a controlled level of thermal energy at the fractured sight locally reducing the modulus and blunting the crack tip, which significantly slows the crack growth rate. By applying a pre-induced strain field and utilizing the shape memory recovery effect, thermal energy can be deployed to close the crack and return

  13. Bacterial foraging-optimized PID control of a two-wheeled machine with a two-directional handling mechanism.

    Science.gov (United States)

    Goher, K M; Fadlallah, S O

    2017-01-01

    This paper presents the performance of utilizing a bacterial foraging optimization algorithm on a PID control scheme for controlling a five DOF two-wheeled robotic machine with two-directional handling mechanism. The system under investigation provides solutions for industrial robotic applications that require a limited-space working environment. The system nonlinear mathematical model, derived using Lagrangian modeling approach, is simulated in MATLAB/Simulink ® environment. Bacterial foraging-optimized PID control with decoupled nature is designed and implemented. Various working scenarios with multiple initial conditions are used to test the robustness and the system performance. Simulation results revealed the effectiveness of the bacterial foraging-optimized PID control method in improving the system performance compared to the PID control scheme.

  14. Biological forcing controls the chemistry of the coral exoskeleton

    Science.gov (United States)

    Meibom, A.; Mostefaoui, S.; Cuif, J.; Yurimoto, H.; Dauphin, Y.; Houlbreque, F.; Dunbar, R.; Constantz, B.

    2006-12-01

    A multitude of marine organisms produce calcium carbonate skeletons that are used extensively to reconstruct water temperature variability of the tropical and subtropical oceans - a key parameter in global climate-change models. Such paleo-climate reconstructions are based on the notion that skeletal oxygen isotopic composition and certain trace-element abundances (e.g., Sr/Ca and Mg/Ca ratios) vary in response to changes in the water temperature. However, it is a fundamental problem that poorly understood biological processes introduce large compositional deviations from thermodynamic equilibrium and hinder precise calibrations of many paleo-climate proxies. Indeed, the role of water temperature in controlling the composition of the skeleton is far from understood. We have studied trace-element abundances as well as oxygen and carbon isotopic compositions of individual skeletal components in the zooxanthellate and non-zooxanthellate corals at ultra-structural, i.e. micrometer to sub-micrometer length scales. From this body of work we draw the following, generalized conclusions: 1) Centers of calcification (COC) are not in equilibrium with seawater. Notably, the Sr/Ca ratio is higher than expected for aragonite equilibrium with seawater at the temperature at which the skeleton was formed. Furthermore, the COC are further away from equilibrium with seawater than fibrous skeleton in terms of stable isotope composition. 2) COC are dramatically different from the fibrous aragonite skeleton in terms of trace element composition. 3) Neither trace element nor stable isotope variations in the fibrous (bulk) part of the skeleton are directly related to changes in SST. In fact, changes in SST can have very little to do with the observed compositional variations. 4) Trace element variations in the fibrous (bulk) part of the skeleton are not related to the activity of zooxanthellae. These observations are directly relevant to the issue of biological versus non-biological

  15. Biological Characteristics and Control of Orobanche Crenata Forsk., a Review

    Directory of Open Access Journals (Sweden)

    Alessia Restuccia

    2009-03-01

    Full Text Available Orobanche crenata is a holoparasitic phanerogam which is particularly noxious to legumes, such as faba bean (Vicia faba L., pea (Pisum sativum L., chickpea (Cicer arietinum L., lentil (Lens culinaris Medik., etc., and commonly considered one of the major causes which has contributed to re-rizing the area designed to their cultivation. After a few brief references on the origin and diffusion of O. crenata, in this work summarises the results of research into biological aspects and control of this species. The information obtained especially concerns seed production, seed viability, seed longevity and dormancy, seed conditioning and germination, parasitism phases, the effects of parasite attacks on host plants and the means of control.

  16. Entomopatogenic fungi as an alternative for biological pest control

    Directory of Open Access Journals (Sweden)

    Pablo Andrés Motta Delgado

    2011-08-01

    Full Text Available The entomopatogenic fungi are a diverse group of microorganisms that provide multiple services to agroecological systems. Among those the capacity to regulate the pests to keep them in suitable levels stands out. The present paper shows a description of the entomopatogenic fungi of most extensively used for the biological control of pests, their mechanism of action on their host, and also investigations about the in vitro and in situ behavior of the mostly used fungi for the control of some insects. Also, the formulations that are used for the development of this biotechnology in the field are described. In the development of bioinsecticides the entomopatogenic fungi are a viable option to minimize environmental damage.

  17. Biological Characteristics and Control of Orobanche Crenata Forsk., a Review

    Directory of Open Access Journals (Sweden)

    Giuseppe Restuccia

    2011-02-01

    Full Text Available Orobanche crenata is a holoparasitic phanerogam which is particularly noxious to legumes, such as faba bean (Vicia faba L., pea (Pisum sativum L., chickpea (Cicer arietinum L., lentil (Lens culinaris Medik., etc., and commonly considered one of the major causes which has contributed to re-rizing the area designed to their cultivation. After a few brief references on the origin and diffusion of O. crenata, in this work summarises the results of research into biological aspects and control of this species. The information obtained especially concerns seed production, seed viability, seed longevity and dormancy, seed conditioning and germination, parasitism phases, the effects of parasite attacks on host plants and the means of control.

  18. Assessing Probabilistic Risk Assessment Approaches for Insect Biological Control Introductions.

    Science.gov (United States)

    Kaufman, Leyla V; Wright, Mark G

    2017-07-07

    The introduction of biological control agents to new environments requires host specificity tests to estimate potential non-target impacts of a prospective agent. Currently, the approach is conservative, and is based on physiological host ranges determined under captive rearing conditions, without consideration for ecological factors that may influence realized host range. We use historical data and current field data from introduced parasitoids that attack an endemic Lepidoptera species in Hawaii to validate a probabilistic risk assessment (PRA) procedure for non-target impacts. We use data on known host range and habitat use in the place of origin of the parasitoids to determine whether contemporary levels of non-target parasitism could have been predicted using PRA. Our results show that reasonable predictions of potential non-target impacts may be made if comprehensive data are available from places of origin of biological control agents, but scant data produce poor predictions. Using apparent mortality data rather than marginal attack rate estimates in PRA resulted in over-estimates of predicted non-target impact. Incorporating ecological data into PRA models improved the predictive power of the risk assessments.

  19. INTEGRATED MANAGEMENT OF CHROMOLAENA ODORATA EMPHASIZING THE CLASSICAL BIOLOGICAL CONTROL

    Directory of Open Access Journals (Sweden)

    SOEKISMAN TJITROSEMITO

    1998-01-01

    Full Text Available Chromolaena odorata, Siam weed, a very important weed of Java Island (Indonesia is native to Central and South America. In the laboratory it showed rapid growth (1.15 g/g/week in the first 8 weeks of its growth. The biomass was mainly as leaves (LAR : 317.50 cm'/g total weight. It slowed down in the following month as the biomass was utilized for stem and branch formation. This behavior supported the growth of C. odorata into a very dense stand. It flowered, fruited during the dry season, and senesced following maturation of seeds from inflorescence branches. These branches dried out, but soon the stem resumed aggressive growth following the wet season. Leaf biomass was affected by the size of the stem in its early phase of regrowth, but later on it was more affected by the number of branches. The introduction of Pareuchaetes pseudoinsulata to Indonesia, was successful only in North Sumatera. In Java it has not been reported to establish succesfully. The introduction of another biological control agent, Procecidochares conneca to Indonesia was shown to be sp ecific and upon release in West Java it established immediately. It spread exponentia lly in the first 6 months of its release. Field monitoring continues to eval uate the impact of the agents. Other biocontrol agents (Actmole anteas and Conotrachelus wilt be introduced to Indonesia in 1997 through ACIAR Project on the Biological Control of Chromolaena odorata in Indonesia and Papua New Guinea.

  20. Reevaluation of the value of autoparasitoids in biological control.

    Directory of Open Access Journals (Sweden)

    Lian-Sheng Zang

    Full Text Available Autoparasitoids with the capacity of consuming primary parasitoids that share the same hosts to produce males are analogous to intraguild predators. The use of autoparasitoids in biological control programs is a controversial matter because there is little evidence to support the view that autoparasitoids do not disrupt and at times may promote suppression of insect pests in combination with primary parasitoids. We found that Encarsia sophia, a facultative autoparasitoid, preferred to use heterospecific hosts as secondary hosts for producing males. The autoparasitoids mated with males originated from heterospecifics may parasitize more hosts than those mated with males from conspecifics. Provided with an adequate number of males, the autoparasitoids killed more hosts than En. formosa, a commonly used parasitoid for biological control of whiteflies. This study supports the view that autoparasitoids in combination with primary parasitoids do not disrupt pest management and may enhance such programs. The demonstrated preference of an autoparasitoid for heterospecifics and improved performance of males from heterospecifics observed in this study suggests these criteria should be considered in strategies that endeavor to mass-produce and utilize autoparasitoids in the future.

  1. Assessing Probabilistic Risk Assessment Approaches for Insect Biological Control Introductions

    Directory of Open Access Journals (Sweden)

    Leyla V. Kaufman

    2017-07-01

    Full Text Available The introduction of biological control agents to new environments requires host specificity tests to estimate potential non-target impacts of a prospective agent. Currently, the approach is conservative, and is based on physiological host ranges determined under captive rearing conditions, without consideration for ecological factors that may influence realized host range. We use historical data and current field data from introduced parasitoids that attack an endemic Lepidoptera species in Hawaii to validate a probabilistic risk assessment (PRA procedure for non-target impacts. We use data on known host range and habitat use in the place of origin of the parasitoids to determine whether contemporary levels of non-target parasitism could have been predicted using PRA. Our results show that reasonable predictions of potential non-target impacts may be made if comprehensive data are available from places of origin of biological control agents, but scant data produce poor predictions. Using apparent mortality data rather than marginal attack rate estimates in PRA resulted in over-estimates of predicted non-target impact. Incorporating ecological data into PRA models improved the predictive power of the risk assessments.

  2. The Bacterial Communities of Full-Scale Biologically Active, Granular Activated Carbon Filters Are Stable and Diverse and Potentially Contain Novel Ammonia-Oxidizing Microorganisms

    Science.gov (United States)

    Hope Wilkinson, Katheryn; Strait, Jacqueline M.; Hozalski, Raymond M.; Sadowksy, Michael J.; Hamilton, Matthew J.

    2015-01-01

    The bacterial community composition of the full-scale biologically active, granular activated carbon (BAC) filters operated at the St. Paul Regional Water Services (SPRWS) was investigated using Illumina MiSeq analysis of PCR-amplified 16S rRNA gene fragments. These bacterial communities were consistently diverse (Shannon index, >4.4; richness estimates, >1,500 unique operational taxonomic units [OTUs]) throughout the duration of the 12-month study period. In addition, only modest shifts in the quantities of individual bacterial populations were observed; of the 15 most prominent OTUs, the most highly variable population (a Variovorax sp.) modulated less than 13-fold over time and less than 8-fold from filter to filter. The most prominent population in the profiles was a Nitrospira sp., representing 13 to 21% of the community. Interestingly, very few of the known ammonia-oxidizing bacteria (AOB; <0.07%) and no ammonia-oxidizing Archaea were detected in the profiles. Quantitative PCR of amoA genes, however, suggested that AOB were prominent in the bacterial communities (amoA/16S rRNA gene ratio, 1 to 10%). We conclude, therefore, that the BAC filters at the SPRWS potentially contained significant numbers of unidentified and novel ammonia-oxidizing microorganisms that possess amoA genes similar to those of previously described AOB. PMID:26209671

  3. Bacterial endophytes of perennial crops for management of plant disease

    OpenAIRE

    Melnick, Rachel L.; Bailey, B.A.; Backman, Paul A.

    2013-01-01

    Metadata only record Bacterial endophytes, microorganisms which inhabit the internal tissues of plants, can suppress disease and are often used as a biological control in annual crops. Less research, however, has been applied to the use of bacterial endophytes to prevent disease in perennial crops, which presents a more complex challenge. However, exploration of their potential as a biological control in perennial crops has been limited. This chapter assembles current knowledge on the subj...

  4. An intrinsically disordered linker controlling the formation and the stability of the bacterial flagellar hook

    OpenAIRE

    Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Freddolino, Peter L.; Samatey, Fadel A.

    2017-01-01

    Background In a macro-molecular complex, any minor change may prove detrimental. For a supra-molecular nano-machine like the bacterial flagellum, which consists of several distinct parts with specific characteristics, stability is important. During the rotation of the bacterial flagellar motor, which is located in the membrane, the flagella rotate at speeds between 200 and 2000 rpm, depending on the bacterial species. The hook substructure of the bacterial flagellum acts as a universal joint ...

  5. Social and economic factors for the adoption of biological control of ...

    African Journals Online (AJOL)

    The results also showed that the decision on the application of biological control is determined by the educational level, income, mechanization level, extension activities, biological control awareness, social participation, attitude toward biological control and access to information sources which have significant influence.

  6. 77 FR 46373 - Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly...

    Science.gov (United States)

    2012-08-03

    ...] Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly Adelgid AGENCY... States for use as a biological control agent to reduce the severity of hemlock woolly adelgid... beetle from the western United States, into the eastern United States for use as a biological control...

  7. 75 FR 28232 - Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly...

    Science.gov (United States)

    2010-05-20

    ...] Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly Adelgid AGENCY..., into the continental United States for use as a biological control agent to reduce the severity of... biological control agent to reduce the severity of hemlock woolly adelgid (HWA) infestations. HWA, an...

  8. 75 FR 69396 - Availability of an Environmental Assessment for a Biological Control Agent for Arundo donax

    Science.gov (United States)

    2010-11-12

    ... Biological Control Agent for Arundo donax AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION... alternatives to, the release of Arundo scale into the continental United States for use as a biological control... a biological control agent to reduce the severity of Arundo donax infestations. A. donax is a highly...

  9. Disease control by chemical and biological fungicides in cultivated mushrooms: button mushroom, oyster mushroom and shiitake

    Directory of Open Access Journals (Sweden)

    Ivana Potočnik

    2015-12-01

    Full Text Available The most commonly cultivated basidiomycetes worldwide and in Serbia are button mushroom (Agaricus bisporus, oyster mushroom (Pleurotus sp. and shiitake (Lentinus edodes. Production of their fruiting bodies is severely afflicted by fungal, bacterial, and viral pathogens that are able to cause diseases which affect yield and quality. Major A. bisporus fungal pathogens include Mycogone perniciosa, Lecanicillium fungicola, and Cladobotryum spp., the causal agents of dry bubble, wet bubble, and cobweb disease, respectively. Various Trichoderma species, the causal agents of green mould, also affect all three kinds of edible mushrooms. Over the past two decades, green mould caused by T. aggressivum has been the most serious disease of button mushroom. Oyster mushroom is susceptible to T. pleurotum and shiitake to T. harzianum. The bacterial brawn blotch disease, caused by Pseudomonas tolaasii, is distributed globally. Disease control on mushroom farms worldwide is commonly based on the use of fungicides. However, evolution of pathogen resistance to fungicides after frequent application, and host sensitivity to fungicides are serious problems. Only a few fungicides are officially recommended in mushroom production: chlorothalonil and thiabendazol in North America and prochloraz in the EU and some other countries. Even though decreased sensitivity levels of L. fungicola and Cladobotryum mycophilum to prochloraz have been detected, disease control is still mainly provided by that chemical fungicide. Considering such resistance evolution, harmful impact to the environment and human health, special attention should be focused on biofungicides, both microbiological products based on Bacillus species and various natural substances of biological origin, together with good programs of hygiene. Introduction of biofungicides has created new possibilities for crop protection with reduced application of chemicals.

  10. Models for integrated pest control and their biological implications.

    Science.gov (United States)

    Tang, Sanyi; Cheke, Robert A

    2008-09-01

    Successful integrated pest management (IPM) control programmes depend on many factors which include host-parasitoid ratios, starting densities, timings of parasitoid releases, dosages and timings of insecticide applications and levels of host-feeding and parasitism. Mathematical models can help us to clarify and predict the effects of such factors on the stability of host-parasitoid systems, which we illustrate here by extending the classical continuous and discrete host-parasitoid models to include an IPM control programme. The results indicate that one of three control methods can maintain the host level below the economic threshold (ET) in relation to different ET levels, initial densities of host and parasitoid populations and host-parasitoid ratios. The effects of host intrinsic growth rate and parasitoid searching efficiency on host mean outbreak period can be calculated numerically from the models presented. The instantaneous pest killing rate of an insecticide application is also estimated from the models. The results imply that the modelling methods described can help in the design of appropriate control strategies and assist management decision-making. The results also indicate that a high initial density of parasitoids (such as in inundative releases) and high parasitoid inter-generational survival rates will lead to more frequent host outbreaks and, therefore, greater economic damage. The biological implications of this counter intuitive result are discussed.

  11. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    KAUST Repository

    Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    -depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to maintain good drinking water microbial quality up

  12. Biological control of Microcystis dominated harmful algal blooms

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... ... as activated carbon and/or oxidative ozone and chlorine (Haider et al., 2003). ... resistant to chemical breakdown and are persistent in natural waters for .... Lysis of cyanobacteria by different bacterial pathogens. Mechanism.

  13. Determination of Economic Control Thresholds for Bacterial Spot on Red Pepper Caused by Xanthomonas campestris pv. vesicatoria

    Directory of Open Access Journals (Sweden)

    Ju-Hee Kim

    2015-06-01

    Full Text Available This study was carried out to develop the economic thresholds for the control of bacterial spot of red pepper. The correlation between diseased leaf rate and yield in field was Y = -0.724X + 281.58, R² = 0.78, r = -0.88**. The correlation between diseased leaf rate and yield loss in field was Y = 0.813X + 15.95, R² = 0.78, r = 0.88*. We found that control thresholds was below 30.3% diseased leaves rate per plant in field. The economic control thresholds for bacterial spot of red pepper was below 16.3%.

  14. Biology and life history of Argopistes tsekooni (Coleoptera: Chrysomelidae) in China, a promising biological control agent of Chinese privet.

    Science.gov (United States)

    Y-Z Zhang; J. Sun; J.L. Hanula

    2009-01-01

    The biology and life history of Argopistes tsekooni Chen (Coleoptera: Chrysomelidae), a potential biological control agent of Chinese privet, Ligustrum sinense Lour., was studied under laboratory and outdoor conditions in Huangshan City of Anhui Province, China, in 2006. A. tsekooni larvae are leafminers that...

  15. Rearing and Release of Megamelus scutellaris Berg (Hemiptera: Delphacidae) for Biological Control of Water hyacinth in 2015

    Science.gov (United States)

    2017-06-01

    Hemiptera: Delphacidae) for Biological Control of Waterhyacinth in 2015 by Jan Freedman and Nathan Harms PURPOSE: Waterhyacinth biological control ... control agents. Three insects were released in the United States for biological control of waterhyacinth during the 1970s; two weevils, Neochetina...content) and competitive interactions with other biological control agents (e.g., Neochetina spp.), though their consideration in other biological

  16. Transfer of toxin genes to alternate bacterial hosts for mosquito control

    Directory of Open Access Journals (Sweden)

    Sergio Orduz

    1995-02-01

    Full Text Available Mosquitoes are vector of serious human and animal diseases, such as malaria, dengue, yellow fever, among others. The use of biological control agents has provide an environmentally safe and highly specific alternative to the use of chemical insecticides in the control of vector borne diseases. Bacillus thuringiensis and B. sphaericus produce toxic proteins to mosquito larvae. Great progress has been made on the biochemical and molecular characterization of such proteins and the genes encoding them. Nevertheless, the low residuality of these biological insecticides is one of the major drawbacks. This article present some interesting aspects of the mosquito larvae feeding habits and review the attempts that have been made to genetically engineer microorganisms that while are used by mosquito larvae as a food source should express the Bacillus toxin genes in order to improve the residuality and stability in the mosquito breeding ponds.

  17. Quagga and zebra mussels: biology, impacts, and control

    Science.gov (United States)

    Nalepa, Thomas F.; Schloesser, Don W.; Nalepa, Thomas F.; Schloesser, Don W.

    2013-01-01

    Quagga and Zebra Mussels: Biology, Impacts, and Control, Second Edition provides a broad view of the zebra/quagga mussel issue, offering a historic perspective and up-to-date information on mussel research. Comprising 48 chapters, this second edition includes reviews of mussel morphology, physiology, and behavior. It details mussel distribution and spread in Europe and across North America, and examines policy and regulatory responses, management strategies, and mitigation efforts. In addition, this book provides extensive coverage of the impact of invasive mussel species on freshwater ecosystems, including effects on water clarity, phytoplankton, water quality, food web changes, and consequences to other aquatic fauna. It also reviews and offers new insights on how zebra and quagga mussels respond and adapt to varying environmental conditions. This new edition includes seven video clips that complement chapter text and, through visual documentation, provide a greater understanding of mussel behavior and distribution.

  18. Diversity and biological activities of the bacterial community associated with the marine sponge Phorbas tenacior (Porifera, Demospongiae).

    Science.gov (United States)

    Dupont, S; Carré-Mlouka, A; Descarrega, F; Ereskovsky, A; Longeon, A; Mouray, E; Florent, I; Bourguet-Kondracki, M L

    2014-01-01

    The diversity of the cultivable microbiota of the marine sponge Phorbas tenacior frequently found in the Mediterranean Sea was investigated, and its potential as a source of antimicrobial, antioxidant and antiplasmodial compounds was evaluated. The cultivable bacterial community was studied by isolation, cultivation and 16S rRNA gene sequencing. Twenty-three bacterial strains were isolated and identified in the Proteobacteria (α or γ classes) and Actinobacteria phyla. Furthermore, three different bacterial morphotypes localized extracellularly within the sponge tissues were revealed by microscopic observations. Bacterial strains were assigned to seven different genera, namely Vibrio, Photobacterium, Shewanella, Pseudomonas, Ruegeria, Pseudovibrio and Citricoccus. The strains affiliated to the same genus were differentiated according to their genetic dissimilarities using random amplified polymorphic DNA (RAPD) analyses. Eleven bacterial strains were selected for evaluation of their bioactivities. Three isolates Pseudovibrio P1Ma4, Vibrio P1MaNal1 and Citricoccus P1S7 revealed antimicrobial activity; Citricoccus P1S7 and Vibrio P1MaNal1 isolates also exhibited antiplasmodial activity, while two Vibrio isolates P1Ma8 and P1Ma5 displayed antioxidant activity. These data confirmed the importance of Proteobacteria and Actinobacteria associated with marine sponges as a reservoir of bioactive compounds. This study presents the first report on the diversity of the cultivable bacteria associated with the marine sponge Phorbas tenacior, frequently found in the Mediterranean Sea. Evaluation of the antiplasmodial, antimicrobial and antioxidant activities of the isolates has been investigated and allowed to select bacterial strains, confirming the importance of Proteobacteria and Actinobacteria as sources of bioactive compounds. © 2013 The Society for Applied Microbiology.

  19. Biological control of biofilms on membranes by metazoans.

    Science.gov (United States)

    Klein, Theresa; Zihlmann, David; Derlon, Nicolas; Isaacson, Carl; Szivak, Ilona; Weissbrodt, David G; Pronk, Wouter

    2016-01-01

    Traditionally, chemical and physical methods have been used to control biofouling on membranes by inactivating and removing the biofouling layer. Alternatively, the permeability can be increased using biological methods while accepting the presence of the biofouling layer. We have investigated two different types of metazoans for this purpose, the oligochaete Aelosoma hemprichi and the nematode Plectus aquatilis. The addition of these grazing metazoans in biofilm-controlled membrane systems resulted in a flux increase of 50% in presence of the oligochaetes (Aelosoma hemprichi), and a flux increase of 119-164% in presence of the nematodes (Plectus aquatilis) in comparison to the control system operated without metazoans. The change in flux resulted from (1) a change in the biofilm structure, from a homogeneous, cake-like biofilm to a more heterogeneous, porous structure and (2) a significant reduction in the thickness of the basal layer. Pyrosequencing data showed that due to the addition of the predators, also the community composition of the biofilm in terms of protists and bacteria was strongly affected. The results have implications for a range of membrane processes, including ultrafiltration for potable water production, membrane bioreactors and reverse osmosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Economic value of biological control in integrated pest management of managed plant systems.

    Science.gov (United States)

    Naranjo, Steven E; Ellsworth, Peter C; Frisvold, George B

    2015-01-07

    Biological control is an underlying pillar of integrated pest management, yet little focus has been placed on assigning economic value to this key ecosystem service. Setting biological control on a firm economic foundation would help to broaden its utility and adoption for sustainable crop protection. Here we discuss approaches and methods available for valuation of biological control of arthropod pests by arthropod natural enemies and summarize economic evaluations in classical, augmentative, and conservation biological control. Emphasis is placed on valuation of conservation biological control, which has received little attention. We identify some of the challenges of and opportunities for applying economics to biological control to advance integrated pest management. Interaction among diverse scientists and stakeholders will be required to measure the direct and indirect costs and benefits of biological control that will allow farmers and others to internalize the benefits that incentivize and accelerate adoption for private and public good.

  1. Use of rhizobacteria and endophytes for biological control of weeds

    Directory of Open Access Journals (Sweden)

    Trognitz, Friederike

    2014-02-01

    Full Text Available Weeds cause severe yield losses in agriculture, with a maximum estimate of 34% of yield loss worldwide due to competition between the crops and the weeds for nutrition, light and humidity (OERKE, 2006. Invasive plants contribute partially to other problems. The pollen of common ragweed, Ambrosia artemisiifolia L., for example, is five times more allergenic than grass pollen; already ten pollen grains per m3 air can trigger allergy in sensitized patients, including rhinitis, conjunctivitis and asthma. This neophyte from America has extended the season of allergy in European patients to October. Common ragweed is currently most frequent in Hungary, France and Italy. In Austria, ragweed populations along roads have increased dramatically since 2000. The effective means to control this weed of the Asteraceae family are limited; a single plant can produce up to 6000 seeds which stay in the soil for 40 years. Control using selective herbicides is not possible within stands of the Asteraceae member sunflower. Efforts to use herbivore insects as biological control agents also failed due to the unavailability of insects specializing on this ragweed. The use of plant-associated rhizobacteria and endophytes as bio-herbicides offers a novel alternative to conventional methods. By analogy to experiences from other plant-microbe systems, the chances to find microbes of the desired characteristics are highest when isolating and testing specimens directly from ragweed plants. These organisms often have an extremely narrow host range that permits their use for the control of among several even closely related plant species growing together in a field.

  2. Thyrotropin-releasing hormone controls mitochondrial biology in human epidermis.

    Science.gov (United States)

    Knuever, Jana; Poeggeler, Burkhard; Gáspár, Erzsébet; Klinger, Matthias; Hellwig-Burgel, Thomas; Hardenbicker, Celine; Tóth, Balázs I; Bíró, Tamás; Paus, Ralf

    2012-03-01

    Mitochondrial capacity and metabolic potential are under the control of hormones, such as thyroid hormones. The most proximal regulator of the hypothalamic-pituitary-thyroid (HPT) axis, TRH, is the key hypothalamic integrator of energy metabolism via its impact on thyroid hormone secretion. Here, we asked whether TRH directly modulates mitochondrial functions in normal, TRH-receptor-positive human epidermis. Organ-cultured human skin was treated with TRH (5-100 ng/ml) for 12-48 h. TRH significantly increased epidermal immunoreactivity for the mitochondria-selective subunit I of respiratory chain complex IV (MTCO1). This resulted from an increased MTCO1 transcription and protein synthesis and a stimulation of mitochondrial biogenesis as demonstrated by transmission electron microscopy and TRH-enhanced mitochondrial DNA synthesis. TRH also significantly stimulated the transcription of several other mitochondrial key genes (TFAM, HSP60, and BMAL1), including the master regulator of mitochondrial biogenesis (PGC-1α). TRH significantly enhanced mitochondrial complex I and IV enzyme activity and enhanced the oxygen consumption of human skin samples, which shows that the stimulated mitochondria are fully vital because the main source for cellular oxygen consumption is mitochondrial endoxidation. These findings identify TRH as a potent, novel neuroendocrine stimulator of mitochondrial activity and biogenesis in human epidermal keratinocytes in situ. Thus, human epidermis offers an excellent model for dissecting neuroendocrine controls of human mitochondrial biology under physiologically relevant conditions and for exploring corresponding clinical applications.

  3. Using Biological-Control Research in the Classroom to Promote Scientific Inquiry & Literacy

    Science.gov (United States)

    Richardson, Matthew L.; Richardson, Scott L.; Hall, David G.

    2012-01-01

    Scientists researching biological control should engage in education because translating research programs into classroom activities is a pathway to increase scientific literacy among students. Classroom activities focused on biological control target all levels of biological organization and can be cross-disciplinary by drawing from subject areas…

  4. Prevalence of Small Intestinal Bacterial Overgrowth among Chronic Pancreatitis Patients: A Case-Control Study.

    Science.gov (United States)

    Therrien, Amelie; Bouchard, Simon; Sidani, Sacha; Bouin, Mickael

    2016-01-01

    Background. Patients with chronic pancreatitis (CP) exhibit numerous risk factors for the development of small intestinal bacterial overgrowth (SIBO). Objective. To determine the prevalence of SIBO in patients with CP. Methods. Prospective, single-centre case-control study conducted between January and September 2013. Inclusion criteria were age 18 to 75 years and clinical and radiological diagnosis of CP. Exclusion criteria included history of gastric, pancreatic, or intestinal surgery or significant clinical gastroparesis. SIBO was detected using a standard lactulose breath test (LBT). A healthy control group also underwent LBT. Results. Thirty-one patients and 40 controls were included. The patient group was significantly older (53.8 versus 38.7 years; P women compared with men was observed (66.6 versus 27.3%; P = 0.056). The subgroups with positive and negative LBTs were comparable in demographic and clinical characteristics, use of opiates, pancreatic enzymes replacement therapy (PERT), and severity of symptoms. Conclusion. The prevalence of SIBO detected using LBT was high among patients with CP. There was no association between clinical features and the risk for SIBO.

  5. Prevalence of Small Intestinal Bacterial Overgrowth among Chronic Pancreatitis Patients: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Amelie Therrien

    2016-01-01

    Full Text Available Background. Patients with chronic pancreatitis (CP exhibit numerous risk factors for the development of small intestinal bacterial overgrowth (SIBO. Objective. To determine the prevalence of SIBO in patients with CP. Methods. Prospective, single-centre case-control study conducted between January and September 2013. Inclusion criteria were age 18 to 75 years and clinical and radiological diagnosis of CP. Exclusion criteria included history of gastric, pancreatic, or intestinal surgery or significant clinical gastroparesis. SIBO was detected using a standard lactulose breath test (LBT. A healthy control group also underwent LBT. Results. Thirty-one patients and 40 controls were included. The patient group was significantly older (53.8 versus 38.7 years; P < 0.01. The proportion of positive LBTs was significantly higher in CP patients (38.7 versus 2.5%: P < 0.01. A trend toward a higher proportion of positive LBTs in women compared with men was observed (66.6 versus 27.3%; P = 0.056. The subgroups with positive and negative LBTs were comparable in demographic and clinical characteristics, use of opiates, pancreatic enzymes replacement therapy (PERT, and severity of symptoms. Conclusion. The prevalence of SIBO detected using LBT was high among patients with CP. There was no association between clinical features and the risk for SIBO.

  6. Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae

    Directory of Open Access Journals (Sweden)

    Da-Ran Kim

    2016-08-01

    Full Text Available Strawberry bacterial angular leaf spot (ALS disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above 32°C. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August, the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%. To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields.

  7. Alien vs. predator: bacterial challenge alters coral microbiomes unless controlled by Halobacteriovorax predators

    Directory of Open Access Journals (Sweden)

    Rory M. Welsh

    2017-05-01

    Full Text Available Coral microbiomes are known to play important roles in organismal health, response to environmental stress, and resistance to disease. The coral microbiome contains diverse assemblages of resident bacteria, ranging from defensive and metabolic symbionts to opportunistic bacteria that may turn harmful in compromised hosts. However, little is known about how these bacterial interactions influence the mechanism and controls of overall structure, stability, and function of the microbiome. We sought to test how coral microbiome dynamics were affected by interactions between two bacteria: Vibrio coralliilyticus, a known temperature-dependent pathogen of some corals, and Halobacteriovorax, a unique bacterial predator of Vibrio and other gram-negative bacteria. We challenged reef-building coral with V. coralliilyticus in the presence or absence of Halobacteriovorax predators, and monitored microbial community dynamics with 16S rRNA gene profiling time-series. Vibrio coralliilyticus inoculation increased the mean relative abundance of Vibrios by greater than 35% from the 4 to 8 hour time point, but not in the 24 & 32 hour time points. However, strong secondary effects of the Vibrio challenge were also observed for the rest of the microbiome such as increased richness (observed species, and reduced stability (increased beta-diversity. Moreover, after the transient increase in Vibrios, two lineages of bacteria (Rhodobacterales and Cytophagales increased in coral tissues, suggesting that V. coralliilyticus challenge opens niche space for these known opportunists. Rhodobacterales increased from 6.99% (±0.05 SEM to a maximum mean relative abundance of 48.75% (±0.14 SEM in the final time point and Cytophagales from <0.001% to 3.656%. Halobacteriovorax predators are commonly present at low-abundance on coral surfaces. Based on the keystone role of predators in many ecosystems, we hypothesized that Halobacteriovorax predators might help protect corals by

  8. BIOLOGICAL CONTROL - AS A MEANS TO CONTROL INSECT PESTS IN AZERBAIJAN

    Directory of Open Access Journals (Sweden)

    Z. M. Mamedov

    2013-01-01

    Full Text Available Two hundreds and twenty species parasites and predators of pests of various agricultures are revealed in Azerbaijan. The complex of entomophages of certain pests of agricultures is studied: 48 species of parasites and predators of Chloridea obsoleta 21 species of entomophages of Pectinophora malvella Hb., over 160 species of entomophages of pests of ozehards and vegetables, 34 species of entomophages of pests of forests. The hundreds species of entomophages and some entomophogenous microbes and antagonists are revealed. Biology and ecology of over 60 species of entomophages and useful microorganisims which are prospective as biological control agents are studied.

  9. Biological control of post harvest disease caused by Aspergillus ...

    African Journals Online (AJOL)

    Antagonistic activity of 24 selected bacterial strains detected by previous microbiological studies to Aspergillus flavus was tested in vitro and in vivo conditions. Within 24 strains, only ten strains showed remarkable inhibition zone (6-34 mm) against the pathogen in assays carried out in Petri plates. Both cell suspension and ...

  10. Promising Biological Indicator of Heavy Metal Pollution: Bioluminescent Bacterial Strains Isolated and Characterized from Marine Niches of Goa, India.

    Science.gov (United States)

    Thakre, Neha A; Shanware, Arti S

    2015-09-01

    In present study, several marine water samples collected from the North Goa Beaches, India for isolation of luminescent bacterial species. Isolates obtained labelled as DP1-5 and AB1-6. Molecular characterization including identification of a microbial culture using 16S rRNA gene based molecular technique and phylogenetic analysis confirmed that DP3 & AB1 isolates were Vibrio harveyi. All of the isolates demonstrated multiple metal resistances in terms of growth, with altered luminescence with variable metal concentration. Present investigations were an attempt towards exploring and reporting an updated diversity of bioluminescent bacterial species from various sites around the Goa, India which would be explored in future for constructing luminescence based biosensor for efficiently monitoring the level of hazardous metals in the environment.

  11. Bacterial Diversity Studies Using the 16S rRNA Gene Provide a Powerful Research-Based Curriculum for Molecular Biology Laboratory

    Directory of Open Access Journals (Sweden)

    Bryan E. Dutton

    2002-12-01

    Full Text Available We have developed a ten-week curriculum for molecular biology that uses 16S ribosomal RNA genes to characterize and compare novel bacteria from hot spring communities in Yellowstone National Park. The 16S rRNA approach bypasses selective culture-based methods. Our molecular biology course offered the opportunity for students to learn broadly applicable methods while contributing to a long-term research project. Specifically, students isolated and characterized clones that contained novel 16S rRNA inserts using restriction enzyme, DNA sequencing, and computer-based phylogenetic methods. In both classes, students retrieved novel bacterial 16S rRNA genes, several of which were most similar to Green Nonsulfur bacterial isolates. During class, we evaluated student performance and mastery of skills and concepts using quizzes, formal lab notebooks, and a broad project assignment. For this report, we also assessed student performance alongside data quality and discussed the significance, our goal being to improve both research and teaching methods.

  12. Possibilities of avoidance and control of bacterial plant diseases when using pathogen-tested (certified) or - treated planting material

    NARCIS (Netherlands)

    Janse, J.; Wenneker, M.

    2002-01-01

    Testing of planting material for freedom from phytopathogenic bacteria is an important, although not exclusive, method for control of bacterial diseases of plants. Ideally, pathogen-free or pathogen-/disease-resistant planting material is desirable, but this situation is not always possible on a

  13. Detection of Pneumocystis DNA in samples from patients suspected of bacterial pneumonia--a case-control study

    DEFF Research Database (Denmark)

    Helweg-Larsen, Jannik; Jensen, Jørgen Skov; Dohn, Birthe

    2002-01-01

    Pneumocystis jiroveci (formerly known as P. carinii f.sp. hominis) is an opportunistic fungus that causes Pneumocystis pneumonia (PCP) in immunocompromised individuals. Pneumocystis jiroveci can be detected by polymerase chain reaction (PCR). To investigate the clinical importance of a positive P...... Pneumocystis-PCR among HIV-uninfected patients suspected of bacterial pneumonia, a retrospective matched case-control study was conducted....

  14. Implications of Plasmodium vivax Biology for Control, Elimination, and Research

    Science.gov (United States)

    Olliaro, Piero L.; Barnwell, John W.; Barry, Alyssa; Mendis, Kamini; Mueller, Ivo; Reeder, John C.; Shanks, G. Dennis; Snounou, Georges; Wongsrichanalai, Chansuda

    2016-01-01

    This paper summarizes our current understanding of the biology of Plasmodium vivax, how it differs from Plasmodium falciparum, and how these differences explain the need for P. vivax-tailored interventions. The article further pinpoints knowledge gaps where investments in research are needed to help identify and develop such specific interventions. The principal obstacles to reduce and eventually eliminate P. vivax reside in 1) its higher vectorial capacity compared with P. falciparum due to its ability to develop at lower temperature and over a shorter sporogonic cycle in the vector, allowing transmission in temperate zones and making it less sensitive to vector control measures that are otherwise effective on P. falciparum; 2) the presence of dormant liver forms (hypnozoites), sustaining multiple relapsing episodes from a single infectious bite that cannot be diagnosed and are not susceptible to any available antimalarial except primaquine, with routine deployment restricted by toxicity; 3) low parasite densities, which are difficult to detect with current diagnostics leading to missed diagnoses and delayed treatments (and protracted transmission), coupled with 4) transmission stages (gametocytes) occurring early in acute infections, before infection is diagnosed. PMID:27799636

  15. Biological control of alien and invasive species in agriculture

    International Nuclear Information System (INIS)

    Calvitti, Maurizio; Moretti Riccardo; Lampazzi, Elena

    2015-01-01

    Agricultural production in Europe faces many challenges including limited availability of water, nitrogen input and fossil fuels. It is necessary, therefore, to identify methods of production and new technologies to increase the efficiency of the primary systems, guaranteeing amount of food, quality, safety and eco-sustainability . One of the most important aspects, though often undervalued in relation to the food chain, is the adversity of biological management of agricultural crops due to pests, pathogens or fitomizi with potential invasive already present in the territory or of recent origin alien. In this context, two main objectives should be implemented at the same time reduce production losses and protect the agro-ecosystem. To meet these expectations, as of January 1, 2015 all farms in the European Union countries are bound to the application of the Integrated Defense principles, as indicated by the Directive on the sustainable use of plant protection products (128/09 / EC) .In response to this and other new entomological emergencies plant health and medical-veterinary entomologist researchers of the Laboratory sustainable management of Agro-Ecosystems in ENEA, have directed their research towards the development of innovative systems for the sustainable control of invasive species of insects is in the agricultural sector that health. [it

  16. Synthesis, chemical and biological quality control of radioiodinated peptides

    International Nuclear Information System (INIS)

    Rafii, H.; Khalaj, A.; Beiki, D.; Motameidi, F.; Maloobi, M.; Karimian-dehghan, M.; Keshavarrzi, F.

    2002-01-01

    Iodinated compounds with I-131, 125 and 123 have been widely used for biochemical function studies. In conjunction with SPECT, [I-123] labelled proteins have various diagnostic and therapeutic applications in nuclear medicine. Preparation of some radioiodinated peptides with tyrosine and/or lysine groups on their main chain molecules can be carried out with both direct and indirect methods, but lack of these groups in molecule cause the molecule dose not lend itself for direct radioiodination. In this study, human IgG and Formyl-Methyl-Leucyl-Phenylalanine, FMLF, have been chosen as a model compounds for direct and indirect radioiodination respectively. Here, we will describe the labelling procedure of [I-125] IgG using chloramine-T as a suitable oxidant agent and [I-125 and I-131] FMLF by indirect method using ATE/SIB as a prosthetic group in multi-step reactions. The obtained results for chemical quality control of intermediate radioiodinated SIB by HPLC and two labelled IgG and FMLF will be also discussed. Biological results, biodistribution studies and SPECT scans on mice per-injected labelled FMLF show a low uptake of thyroid but a high at urine and bladder, perhaps because of low molecular weight of FMLF. In this case, it seems to be better to separate the reaction mixture of labelled FMLF by BPLC than Sephadex-G50 gel filtration. (Author)

  17. Implications of Plasmodium vivax Biology for Control, Elimination, and Research.

    Science.gov (United States)

    Olliaro, Piero L; Barnwell, John W; Barry, Alyssa; Mendis, Kamini; Mueller, Ivo; Reeder, John C; Shanks, G Dennis; Snounou, Georges; Wongsrichanalai, Chansuda

    2016-12-28

    This paper summarizes our current understanding of the biology of Plasmodium vivax, how it differs from Plasmodium falciparum, and how these differences explain the need for P. vivax-tailored interventions. The article further pinpoints knowledge gaps where investments in research are needed to help identify and develop such specific interventions. The principal obstacles to reduce and eventually eliminate P. vivax reside in 1) its higher vectorial capacity compared with P. falciparum due to its ability to develop at lower temperature and over a shorter sporogonic cycle in the vector, allowing transmission in temperate zones and making it less sensitive to vector control measures that are otherwise effective on P. falciparum; 2) the presence of dormant liver forms (hypnozoites), sustaining multiple relapsing episodes from a single infectious bite that cannot be diagnosed and are not susceptible to any available antimalarial except primaquine, with routine deployment restricted by toxicity; 3) low parasite densities, which are difficult to detect with current diagnostics leading to missed diagnoses and delayed treatments (and protracted transmission), coupled with 4) transmission stages (gametocytes) occurring early in acute infections, before infection is diagnosed. © The American Society of Tropical Medicine and Hygiene.

  18. Yeast Derived LysA2 Can Control Bacterial Contamination in Ethanol Fermentation

    Directory of Open Access Journals (Sweden)

    Jun-Seob Kim

    2018-05-01

    Full Text Available Contamination of fuel-ethanol fermentations continues to be a significant problem for the corn and sugarcane-based ethanol industries. In particular, members of the Lactobacillaceae family are the primary bacteria of concern. Currently, antibiotics and acid washing are two major means of controlling contaminants. However, antibiotic use could lead to increased antibiotic resistance, and the acid wash step stresses the fermenting yeast and has limited effectiveness. Bacteriophage endolysins such as LysA2 are lytic enzymes with the potential to contribute as antimicrobials to the fuel ethanol industries. Our goal was to evaluate the potential of yeast-derived LysA2 as a means of controlling Lactobacillaceae contamination. LysA2 intracellularly produced by Pichia pastoris showed activity comparable to Escherichia coli produced LysA2. Lactic Acid Bacteria (LAB with the A4α peptidoglycan chemotype (L-Lys-D-Asp crosslinkage were the most sensitive to LysA2, though a few from that chemotype were insensitive. Pichia-expressed LysA2, both secreted and intracellularly produced, successfully improved ethanol productivity and yields in glucose (YPD60 and sucrose-based (sugarcane juice ethanol fermentations in the presence of a LysA2 susceptible LAB contaminant. LysA2 secreting Sacharomyces cerevisiae did not notably improve production in sugarcane juice, but it did control bacterial contamination during fermentation in YPD60. Secretion of LysA2 by the fermenting yeast, or adding it in purified form, are promising alternative tools to control LAB contamination during ethanol fermentation. Endolysins with much broader lytic spectrums than LysA2 could supplement or replace the currently used antibiotics or the acidic wash.

  19. Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

    Science.gov (United States)

    Rahman, M. M.; Ali, M. E.; Khan, A. A.; Akanda, A. M.; Uddin, Md. Kamal; Hashim, U.; Abd Hamid, S. B.

    2012-01-01

    A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacterium Erwinia carotovora subsp. carotovora (Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was tested in vitro against the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited the in vitro growth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genus Bacillus and the isolate E-45 as Lactobacillus sp. The stronger antagonistic activity against Ecc P-138 was found in E-65 in vitro screening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers. PMID:22645446

  20. Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacterium Erwinia carotovora subsp. carotovora (Ecc were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was tested in vitro against the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited the in vitro growth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genus Bacillus and the isolate E-45 as Lactobacillus sp. The stronger antagonistic activity against Ecc P-138 was found in E-65 in vitro screening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5% antagonistic effect of E-65 was observed in the Granola and the lowest (32.7% of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

  1. Synthetic biology and regulatory networks: where metabolic systems biology meets control engineering

    NARCIS (Netherlands)

    He, F.; Murabito, E.; Westerhoff, H.V.

    2016-01-01

    Metabolic pathways can be engineered to maximize the synthesis of various products of interest. With the advent of computational systems biology, this endeavour is usually carried out throughin silicotheoretical studies with the aim to guide and complement furtherin vitroandin vivoexperimental

  2. Pythium species and isolate diversity influence inhibition by the biological control agent Streptomyces lydicus

    Science.gov (United States)

    Disease control of soilborne pathogens by biological control agents has often been inconsistent under field conditions. One factor that may contribute to this inconsistency is the variability in response among pathogen populations and/or communities to the selected biological control agent. One hund...

  3. 76 FR 3076 - Availability of an Environmental Assessment for a Biological Control Agent for Air Potato

    Science.gov (United States)

    2011-01-19

    ...] Availability of an Environmental Assessment for a Biological Control Agent for Air Potato AGENCY: Animal and... environmental assessment (EA) relative to the control of air potato (Dioscorea bulbifera). The EA considers the... States for use as a biological control agent to reduce the severity of air potato infestations. We are...

  4. Augmentative biological control in the Mexican national fruit fly campaign

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, P [Campana Nacional Moscas de la Fruta, DGSV-SAGARPA (Mexico); Cancino, J; Gutierrez, J M; Santiago, G [Campana Nacional Moscas de la Fruta, DGSV-SAGARPA (Mexico)

    2005-07-01

    Full text: Tephritid fruit flies are some of the most economically important species of insects worldwide. In Mexico, the native Anastrepha ludens, A. obliqua, A. serpentina and A. striata, are among the most important problems because of the great number of commercial fruits they attack. In an attempt to solve the Anastrepha fruit flies problems, the Mexican Government created the National Campaign against Fruit Flies in 1992. Using an area-wide approach and an integrated pest management framework, that included the use of environment-friendly strategies to suppress/eradicate fruit flies, the Mexican Campaign has integrated different technologies such as the application of specific toxic bait, the use of the Sterile Insect Technique (SIT), and the release of the endoparasitoid Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae), which attacks preferably third instar larvae of fruit flies. Since 1995, the Moscafrut mass-rearing facility has the capacity to produce an average of 50 millions of parasitised pupae per week, with 65-70% of parasitoid emergence using irradiated A. ludens larvae as host. The mass-rearing procedures of D. longicaudata have been fully described by Cancino. Parasitised pupae are sent via commercial flights to several states of the country (i.e. Michoacan, Sinaloa, Nayarit, Tamaulipas), according to a yearly national plan. This plan derives from industry requirements and/or availability of biological material. In the target zones, parasitoids are released in specific periods and specific areas where the environmental, biological and social conditions are considered as adequate. Packing and release procedures of parasitoids follow those that Montoya et al used. The releases are focused on Anastrepha spp. host trees located in marginal areas (i.e backyard orchards), with the objective to prevent the migration of fruit fly populations into commercial orchards. The impact of parasitoids on fruit fly populations is evaluated through

  5. EVALUATION OF BIOTIC AND TREATMENT FACTORS RELATING TO BACTERIAL CONTROL OF ZEBRA MUSSELS

    International Nuclear Information System (INIS)

    Molloy, Daniel P.

    2002-01-01

    Testing over the last quarter has indicated the following regarding control of zebra mussels with bacterium Pseudomonas fluorescens strain CL0145A: (1) the concentration of bacteria suspended in water is directly correlated with mussel kill; (2) the ratio of bacterial mass per mussel, if too low, could limit mussel kill; a treatment must be done at a high enough ratio so that mussels do not deplete all the suspended bacteria before the end of the desired exposure period; (3) bacteria appear to lose almost all their toxicity after suspension for 24 hr in highly oxygenated water; (4) in a recirculating pipe system, the same percentage mussel kill will be achieved irrespective of whether all the bacteria are applied at once or divided up and applied intermittently in smaller quantities over a 10-hr period. Since this is the fourth quarterly report, a summation of all test results over the last twelve months is provided as a table in this report. The table includes the above-mentioned fourth-quarter results

  6. EVALUATION OF BIOTIC AND TREATMENT FACTORS RELATING TO BACTERIAL CONTROL OF ZEBRA MUSSELS

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2002-04-30

    Testing over the last quarter has indicated the following regarding control of zebra mussels with bacterium Pseudomonas fluorescens strain CL0145A: (1) the concentration of bacteria suspended in water is directly correlated with mussel kill; (2) the ratio of bacterial mass per mussel, if too low, could limit mussel kill; a treatment must be done at a high enough ratio so that mussels do not deplete all the suspended bacteria before the end of the desired exposure period; (3) bacteria appear to lose almost all their toxicity after suspension for 24 hr in highly oxygenated water; (4) in a recirculating pipe system, the same percentage mussel kill will be achieved irrespective of whether all the bacteria are applied at once or divided up and applied intermittently in smaller quantities over a 10-hr period. Since this is the fourth quarterly report, a summation of all test results over the last twelve months is provided as a table in this report. The table includes the above-mentioned fourth-quarter results.

  7. Patterns and controls on nitrogen cycling of biological soil crusts

    Science.gov (United States)

    Barger, Nichole N.; Zaady, Eli; Weber, Bettina; Garcia-Pichel, Ferran; Belnap, Jayne

    2016-01-01

    Biocrusts play a significant role in the nitrogen [N ] cycle within arid and semi-arid ecosystems, as they contribute major N inputs via biological fixation and dust capture, harbor internal N transformation processes, and direct N losses via N dissolved, gaseous and erosional loss processes (Fig. 1). Because soil N availability in arid and semi-arid ecosystems is generally low and may limit net primary production (NPP), especially during periods when adequate water is available, understanding the mechanisms and controls of N input and loss pathways in biocrusts is critically important to our broader understanding of N cycling in dryland environments. In particular, N cycling by biocrusts likely regulates short-term soil N availability to support vascular plant growth, as well as long-term N accumulation and maintenance of soil fertility. In this chapter, we review the influence of biocrust nutrient input, internal cycling, and loss pathways across a range of biomes. We examine linkages between N fixation capabilities of biocrust organisms and spatio-temporal patterns of soil N availability that may influence the longer-term productivity of dryland ecosystems. Lastly, biocrust influence on N loss pathways such as N gas loss, leakage of N compounds from biocrusts, and transfer in wind and water erosion are important to understand the maintenance of dryland soil fertility over longer time scales. Although great strides have been made in understanding the influence of biocrusts on ecosystem N cycling, there are important knowledge gaps in our understanding of the influence of biocrusts on ecosystem N cycling that should be the focus of future studies. Because work on the interaction of N cycling and biocrusts was reviewed in Belnap and Lange (2003), this chapter will focus primarily on research findings that have emerged over the last 15 years (2000-2015).

  8. Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

    OpenAIRE

    Lucas,Gilvaine Ciavareli; Alves,Eduardo; Pereira,Ricardo Borges; Perina,Fabiano José; Souza,Ricardo Magela de

    2012-01-01

    The objective of this work was to evaluate the effects of plant essential oils (EOs) on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings unde...

  9. Bacterial Peptide Deformylase Inhibition of Tetrazole-Substituted Biaryl Acid Analogs: Synthesis, Biological Evaluations, and Molecular Docking Study.

    Science.gov (United States)

    Khan, Firoz A Kalam; Patil, Rajendra H; Patil, Manjiri; Arote, Rohidas; Shinde, Devanand B; Sangshetti, Jaiprakash N

    2016-12-01

    The synthesis and screening of tetrazole-substituted biaryl acid analogs 7a-l as bacterial peptide deformylase (PDF) enzyme inhibitors is reported. The compounds 7e (IC 50 value = 5.50 μM) and 7g (IC 50 value = 7.25 μM) showed good PDF inhibition activity. The compounds 7e (MIC range = 10.75-11.66 μg/mL) and 7g (MIC range = 8.91-12.83 μg/mL) also showed potent antibacterial activity when compared with the standard ciprofloxacin (MIC range = 25-50 μg/mL). Thus, the active derivatives were not only potent PDF enzyme inhibitors but also efficient antibacterial agents. In order to gain more insight into the binding mode of the compounds with the PDF enzyme, the most active compounds 7e and 7g, the moderately active compound 7k, and the least active compound 7h were docked against the PDF enzyme of Escherichia coli. The docking study of the most active compounds 7e and 7g against the PDF enzyme exhibited good binding properties. Hence, we believe our synthesized compounds 7a-l could serve as reservoir for bacterial PDF inhibitor development. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Biological control of Aspergillus flavus growth and subsequent ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... 1School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia,. 2Department of Botany, Osmania University, Hyderabad, India. ... the biocontrol agents tested, culture filtrate of Rhodococcus ...

  11. WILD PIGS: BIOLOGY, DAMAGE, CONTROL TECHINQUES AND MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, John; Brisbin, I. Lehr

    2009-12-31

    about anything; and, they can live just about anywhere. On top of that, wild pigs are both very difficult to control and, with the possible exception of island ecosystems, almost impossible to eradicate (Dickson et al. 2001, Sweeney et al. 2003). The solution to the wild pig problem has not been readily apparent. The ultimate answer as to how to control these animals has not been found to date. In many ways, wild pigs are America's most successful large invasive species. All of which means that wild pigs are a veritable nightmare for land and resource managers trying to keep the numbers of these animals and the damage that they do under control. Since the more that one knows about an invasive species, the easier it is to deal with and hopefully control. For wild pigs then, it is better to 'know thy enemy' than to not, especially if one expects to be able to successfully control them. In an effort to better 'know thy enemy,' a two-day symposium was held in Augusta, Georgia, on April 21-22, 2004. This symposium was organized and sponsored by U.S.D.A. Forest Service-Savannah River (USFS-SR), U. S. Department of Energy-Savannah River Operations Office (DOE-SR), the Westinghouse Savannah River Company (WSRC), the South Carolina Chapter of the Soil & Water Conservation Society, and the Savannah River Ecology Laboratory (SREL). The goal of this symposium was to assemble researchers and land managers to first address various aspects of the biology and damage of wild pigs, and then review the control techniques and management of this invasive species. The result would then be a collected synopsis of what is known about wild pigs in the United States. Although the focus of the symposium was primarily directed toward federal agencies, presenters also included professionals from academic institutions, and private-sector control contractors and land managers. Most of the organizations associated with implementing this symposium were affiliated with the

  12. [Characterization of a bacterial biocontrol strain 1404 and its efficacy in controlling postharvest citrus anthracnose].

    Science.gov (United States)

    Wang, Qian; Hu, Chunjin; Ke, Fanggang; Huang, Siliang; Li, Qiqin

    2010-09-01

    Anthracnose caused by Colletotrichum gloeosporioides (Penz.) Sacc. is a main disease in citrus production. To develop an effective biocontrol measure against citrus postharvest anthracnose, we screened antagonistic microbes and obtained a bacterial strain 1404 from the rhizospheric soil of chili plants in Nanning city, Guangxi, China. The objectives of the present study were to: (1) identify and characterize the antagonistic bacterium; and (2) to evaluate the efficacy of the antagonistic strain in controlling citrus postharvest anthracnose disease. Strain 1404 was identified by comparing its 16S rDNA sequence with related bacteria from GenBank database, as well as analyzing its morphological, physiological and biochemical characters. The antagonistic stability of the strain 1404 was determined by continuously transferring it on artificial media. The effect of the strain on suppressing citrus anthracnose at postharvest stage was tested by stab inoculation method. The 16S rDNA of strain 1404 was amplified with primers PF1 (5'-AGAGTTTGATCATGGCTCAG-3') and PR1 (5'-TACGGTTACCTTGTTACGACTT-3') and its sequence submitted to GenBank (accession number: GU361113). Strain 1404 clustered with the GenBank-derived Brevibacillus brevis strains in the 16S-rDNA-sequence-based phylogenetic tree at 100% bootstrap level. The morphological traits, physiological and biochemical characters of strain 1404 agreed with that of Brevibacillus brevis. Less change in the suppressive ability of antagonist against growth of Colletotrichum gloeosporioides was observed during four continuous transfers on artificial media. The average control efficacy of the strain was 64. 9 % against the disease 20 days after the antagonist application. Strain 1404 was identified as Brevibacillus brevis based on its morphological traits, phyiological and biochemical characters as well as 16S rDNA sequence analysis. The antagonist was approved to be a promising biocontrol agent. This is the first report of

  13. Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma: a nested case-control study.

    NARCIS (Netherlands)

    Fedirko, Veronika; Tran, Hao Quang; Gewirtz, Andrew T; Stepien, Magdalena; Trichopoulou, Antonia; Aleksandrova, Krasimira; Olsen, Anja; Tjønneland, Anne; Overvad, Kim; Carbonnel, Franck; Boutron-Ruault, Marie-Christine; Severi, Gianluca; Kühn, Tilman; Kaaks, Rudolf; Boeing, Heiner; Bamia, Christina; Lagiou, Pagona; Grioni, Sara; Panico, Salvatore; Palli, Domenico; Tumino, Rosario; Naccarati, Alessio; Peeters, Petra H; Bueno-de-Mesquita, H B; Weiderpass, Elisabete; Castaño, José María Huerta; Barricarte, Aurelio; Sánchez, María-José; Dorronsoro, Miren; Quirós, J Ramón; Agudo, Antonio; Sjöberg, Klas; Ohlsson, Bodil; Hemmingsson, Oskar; Werner, Mårten; Bradbury, Kathryn E; Khaw, Kay-Tee; Wareham, Nick; Tsilidis, Konstantinos K; Aune, Dagfinn; Scalbert, Augustin; Romieu, Isabelle; Riboli, Elio; Jenab, Mazda

    2017-01-01

    Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking.

  14. Biological control of potato black scurf by rhizosphere associated bacteria

    Directory of Open Access Journals (Sweden)

    Mohsin Tariq

    2010-06-01

    Full Text Available The present work was carried out to study the potential of plant rhizosphere associated bacteria for the biocontrol of potato black scurf disease caused by Rhizoctonia solani Khun AG-3. A total of twenty-eight bacteria isolated from diseased and healthy potato plants grown in the soil of Naran and Faisalabad, Pakistan were evaluated for their antagonistic potential. Nine bacterial strains were found to be antagonistic in vitro, reduced the fungal growth and caused the lysis of sclerotia of R. solani in dual culture assay as well as in extracellular metabolite efficacy test. The selected antagonistic strains were further tested for the production and efficacy of volatile and diffusible antibiotics, lytic enzymes and siderophores against R. solani. Selected antagonistic bacteria were also characterized for growth promoting attributes i.e., phosphate solubilization, nitrogen fixation and indole acetic acid production. Biocontrol efficacy and percent yield increase by these antagonists was estimated in greenhouse experiment. Statistical analysis showed that two Pseudomonas spp. StT2 and StS3 were the most effective with 65.1 and 73.9 percent biocontrol efficacy, as well as 87.3 and 98.3 percent yield increase, respectively. Potential antagonistic bacterial strain StS3 showed maximum homology to Pseudomonas sp. as determined by 16S rRNA gene sequencing. These results suggest that bacterial isolates StS3 and StT2 have excellent potential to be used as effective biocontrol agents promoting plant growth with reduced disease incidence.

  15. Coupling Spatial Segregation with Synthetic Circuits to Control Bacterial Survival (Open Access)

    Science.gov (United States)

    2016-02-29

    gated by encapsulation ( APA membrane), we developed a full model, specific for the BlaM circuit to account for the essential reac- tions involved in...L-lysine)-alginate ( APA ) microcapsules containing bacterial cells were fabricated by a soft lithography technique (Duffy et al, 1998). The...HB, Kolter R (2000) BIOFILM FORMATION AS MICROBIAL DEVELOPMENT. Annu Rev Microbiol 54: 49 – 79 Pai A, You L (2009) Optimal tuning of bacterial sensing

  16. The role of ionizing radiation in biological control of agricultural pests

    International Nuclear Information System (INIS)

    Mansour, M.

    2011-01-01

    Although the commercial biological control industry is growing, it still represents only a small portion of the international market of pest control sales (about 3%). This low ratio is due to several factors including high cost of production of biological control agents and technical and regulatory difficulties that complicate the shipping procedures and create trade barriers. This article summarizes the role of ionizing radiation in supporting the use of biological control agents in insect pest control and concentrates on its role in the production, transport, distribution, and release of parasites and predators and the advantages that ionizing radiation can offer, in comparison with traditional techniques. (author)

  17. Is intravesical instillation of hyaluronic acid and chondroitin sulfate useful in preventing recurrent bacterial cystitis? A multicenter case control analysis.

    Science.gov (United States)

    Gugliotta, Giorgio; Calagna, Gloria; Adile, Giorgio; Polito, Salvatore; Saitta, Salvatore; Speciale, Patrizia; Palomba, Stefano; Perino, Antonino; Granese, Roberta; Adile, Biagio

    2015-10-01

    Urinary tract infections (UTIs) are common in the female population and, over a lifetime, about half of women have at least one episode of UTI requiring antibiotic therapy. The aim of the current study was to compare two different strategies for preventing recurrent bacterial cystitis: intravesical instillation of hyaluronic acid (HA) plus chondroitin sulfate (CS), and antibiotic prophylaxis with sulfamethoxazole plus trimethoprim. This was a retrospective review of two different cohorts of women affected by recurrent bacterial cystitis. Cases (experimental group) were women who received intravesical instillations of a sterile solution of high concentration of HA + CS in 50 mL water with calcium chloride every week during the 1(st) month and then once monthly for 4 months. The control group included women who received traditional therapy for recurrent cystitis based on daily antibiotic prophylaxis using sulfamethoxazole 200 mg plus trimethoprim 40 mg for 6 weeks. Ninety-eight and 76 patients were treated with experimental and control treatments, respectively. At 12 months after treatment, 69 and 109 UTIs were detected in the experimental and control groups, respectively. The proportion of patients free from UTIs was significantly higher in the experimental than in the control group (36.7% vs. 21.0%; p = 0.03). Experimental treatment was well tolerated and none of the patients stopped it. The intravesical instillation of HA + CS is more effective than long-term antibiotic prophylaxis for preventing recurrent bacterial cystitis. Copyright © 2015. Published by Elsevier B.V.

  18. Radiochemical and biological control of metaiodobenzyl-guanidine (MIBG) labeled with 131I

    International Nuclear Information System (INIS)

    Barboza, M.R.F.F. de; Muramoto, E.; Colturato, M.T.; Silva Valente Goncalves, R. da; Pereira, N.P.S. de; Almeida, M.A.T.M. de; Silva, C.P.G. da.

    1988-07-01

    This study shows the standardization of the radiochemical control of MIBG - 131 I in eletrophoretic system and also the biological control in Wistar rat for a period of time, not longer than 60 minutes after tracer administration. (author) [pt

  19. Biological control of fusarium wilt of tomato by antagonist fungi and ...

    African Journals Online (AJOL)

    Yomi

    2012-01-16

    Jan 16, 2012 ... Key words: Biological control, fusarium wilt, tomato, antagonist fungi, cyanobacteria. INTRODUCTION ... severely affected by wilt disease caused by F. oxysporum f. sp. ..... Changing options for the control of deciduous fruit.

  20. Assessment of uranium and selenium speciation in human and bacterial biological models to probe changes in their structural environment

    Energy Technology Data Exchange (ETDEWEB)

    Avoscan, L.; Milgram, S.; Untereiner, G.; Collins, R.; Khodja, H.; Carriere, M.; Gouget, B. [Lab. Pierre Sue, CEA-CNRS UMR 9956, CEA/Saclay, Gif-sur-Yvette (France); Coves, J. [Inst. de Biologie Structurale - J.-P. Ebel, Lab. des Proteines Membranaires, Grenoble (France); Hazemann, J.L. [Lab. de Geophysique Interne et Tectonopbysique, UMR CNRS/Univ. Joseph Fourier, Saint-Martin-D' Heres (France)

    2009-07-01

    This study illustrates the potential of physicochemical techniques to speciate uranium (U) and selenium (Se) in biological samples. Speciation, defined he0re as the study of structural environment, of both toxic elements, was characterized at several levels in biological media and directly in human cells or bacteria once the metal(loid)s were internalized. External speciation that is extracellular speciation in culture media was predicted by thermodynamic equilibrium computer modelling using the JChess software and validated by spectroscopic measurements (XANES and EXAFS). Internal speciation that is intracellular speciation in eukaryotic and prokaryotic cells was studied in vitro with a soil bacterium Cupriavidus metallidurans CH34 and ROS 17/2.8 osteoblasts, human cells responsible for bone formation. XANES, EXAFS, HPLC-ICP-MS and SDS-PAGE coupled to particle induced X-ray emission (PIXE) permitted the identification and quantification of complexes formed with organic or inorganic molecules and/or larger proteins. (orig.)

  1. Assessment of uranium and selenium speciation in human and bacterial biological models to probe changes in their structural environment

    International Nuclear Information System (INIS)

    Avoscan, L.; Milgram, S.; Untereiner, G.; Collins, R.; Khodja, H.; Carriere, M.; Gouget, B.; Coves, J.; Hazemann, J.L.

    2009-01-01

    This study illustrates the potential of physicochemical techniques to speciate uranium (U) and selenium (Se) in biological samples. Speciation, defined he0re as the study of structural environment, of both toxic elements, was characterized at several levels in biological media and directly in human cells or bacteria once the metal(loid)s were internalized. External speciation that is extracellular speciation in culture media was predicted by thermodynamic equilibrium computer modelling using the JChess software and validated by spectroscopic measurements (XANES and EXAFS). Internal speciation that is intracellular speciation in eukaryotic and prokaryotic cells was studied in vitro with a soil bacterium Cupriavidus metallidurans CH34 and ROS 17/2.8 osteoblasts, human cells responsible for bone formation. XANES, EXAFS, HPLC-ICP-MS and SDS-PAGE coupled to particle induced X-ray emission (PIXE) permitted the identification and quantification of complexes formed with organic or inorganic molecules and/or larger proteins. (orig.)

  2. The status of biological control and recommendations for improving uptake for the future

    NARCIS (Netherlands)

    Barratt, B.I.P.; Moran, V.C.; Bigler, F.; Lenteren, van J.C.

    2018-01-01

    Classical and augmentative biological control of insect pests and weeds has enjoyed a long history of successes. However, biocontrol practices have not been as universally accepted or optimally utilised as they could be. An International Organisation for Biological Control (IOBC) initiative brought

  3. 21 CFR 310.4 - Biologics; products subject to license control.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Biologics; products subject to license control... to license control. (a) If a drug has an approved license under section 351 of the Public Health.... (b) To obtain marketing approval for radioactive biological products for human use, as defined in...

  4. Managing conflict over biological control: the case of strawberry guava in Hawaii

    Science.gov (United States)

    Tracy Johnson

    2016-01-01

    Biological control researchers commonly avoid targets with potential for high conflict, but for certain highly damaging invaders with no viable management alternatives, it may be necessary to consider biological control even when it is likely to generate conflict. Discussed here is a case study, strawberry guava (Psidium cattleianum Sabine...

  5. Control of corrosive bacterial community by bronopol in industrial water system.

    Science.gov (United States)

    Narenkumar, Jayaraman; Ramesh, Nachimuthu; Rajasekar, Aruliah

    2018-01-01

    Ten aerobic corrosive bacterial strains were isolated from a cooling tower water system (CWS) which were identified based on the biochemical characterization and 16S rRNA gene sequencing. Out of them, dominant corrosion-causing bacteria, namely, Bacillus thuringiensis EN2, Terribacillus aidingensis EN3, and Bacillus oleronius EN9, were selected for biocorrosion studies on mild steel 1010 (MS) in a CWS. The biocorrosion behaviour of EN2, EN3, and EN9 strains was studied using immersion test (weight loss method), electrochemical analysis, and surface analysis. To address the corrosion problems, an anti-corrosive study using a biocide, bronopol was also demonstrated. Scanning electron microscopy and Fourier-transform infrared spectroscopy analyses of the MS coupons with biofilm developed after exposure to CWS confirmed the accumulation of extracellular polymeric substances and revealed that biofilms was formed as microcolonies, which subsequently cause pitting corrosion. In contrast, the biocide system, no pitting type of corrosion, was observed and weight loss was reduced about 32 ± 2 mg over biotic system (286 ± 2 mg). FTIR results confirmed the adsorption of bronopol on the MS metal surface as protective layer (co-ordination of NH 2 -Fe 3+ ) to prevent the biofilm formation and inhibit the corrosive chemical compounds and thus led to reduction of corrosion rate (10 ± 1 mm/year). Overall, the results from WL, EIS, SEM, XRD, and FTIR concluded that bronopol was identified as effective biocide and corrosion inhibitor which controls the both chemical and biocorrosion of MS in CWS.

  6. Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain

    Science.gov (United States)

    Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Micklem, Chris N.; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S.; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

    2016-01-01

    Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae. Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology. PMID:27247386

  7. Halomonas desiderata as a bacterial model to predict the possible biological nitrate reduction in concrete cells of nuclear waste disposals.

    Science.gov (United States)

    Alquier, Marjorie; Kassim, Caroline; Bertron, Alexandra; Sablayrolles, Caroline; Rafrafi, Yan; Albrecht, Achim; Erable, Benjamin

    2014-01-01

    After closure of a waste disposal cell in a repository for radioactive waste, resaturation is likely to cause the release of soluble species contained in cement and bituminous matrices, such as ionic species (nitrates, sulfates, calcium and alkaline ions, etc.), organic matter (mainly organic acids), or gases (from steel containers and reinforced concrete structures as well as from radiolysis within the waste packages). However, in the presence of nitrates in the near-field of waste, the waste cell can initiate oxidative conditions leading to enhanced mobility of redox-sensitive radionuclides (RN). In biotic conditions and in the presence of organic matter and/or hydrogen as electron donors, nitrates may be microbiologically reduced, allowing a return to reducing conditions that promote the safety of storage. Our work aims to analyze the possible microbial reactivity of nitrates at the bitumen - concrete interface in conditions as close as possible to radioactive waste storage conditions in order (i) to evaluate the nitrate reaction kinetics; (ii) to identify the by-products (NO2(-), NH4(+), N2, N2O, etc.); and (iii) to discriminate between the roles of planktonic bacteria and those adhering as a biofilm structure in the denitrifying activity. Leaching experiments on solid matrices (bitumen and cement pastes) were first implemented to define the physicochemical conditions that microorganisms are likely to meet at the bitumen-concrete interface, e.g. highly alkaline pH conditions (10 < pH < 11) imposed by the cement matrix. The screening of a range of anaerobic denitrifying bacterial strains led us to select Halomonas desiderata as a model bacterium capable of catalyzing the reaction of nitrate reduction in these particular conditions of pH. The denitrifying activity of H. desiderata was quantified in a batch bioreactor in the presence of solid matrices and/or leachate from bitumen and cement matrices. Denitrification was relatively fast in the presence of cement

  8. Biological stability of drinking water : Controlling factors, methods, and challenges

    NARCIS (Netherlands)

    Prest, E.I.E.D.; Hammes, F.; Van Loosdrecht, M.C.M.; Vrouwenvelder, J.S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and

  9. Characterization of the bacterial community in a biotrickling filter treating high loads of H(2)S by molecular biology tools.

    Science.gov (United States)

    Maestre, Juan P; Rovira, Roger; Gamisans, Xavier; Kinney, Kerry A; Kirisits, Mary Jo; Lafuente, Javier; Gabriel, David

    2009-01-01

    The diversity and spatial distribution of bacteria in a lab-scale biotrickling filter treating high loads of hydrogen sulfide (H(2)S) were investigated. Diversity and community structure were studied by terminal-restriction fragment length polymorphism (T-RFLP). A 16S rRNA gene clone library was established. Near Full-length 16S rRNA gene sequences were obtained, and clones were clustered into 24 operational taxonomic units (OTUs). Nearly 74% and 26% of the clones were affiliated with the phyla Proteobacteria and Bacteroidetes, respectively. Beta-, epsilon- and gamma-proteobacteria accounted for 15, 9 and 48%, respectively. Around 45% of the sequences retrieved were affiliated to bacteria of the sulfur cycle including Thiothrix spp., Thiobacillus spp. and Sulfurimonas denitrificans. Sequences related to Thiothrix lacustris accounted for a 38%. Rarefaction curve demonstrated that clone library constructed can be sufficient to describe the vast majority of the bacterial diversity of this reactor operating under strict conditions (2,000 ppm(v) of H(2)S). A spatial distribution of bacteria was found along the length of the reactor by means of the T-RFLP technique. Although aerobic species were predominant along the reactor, facultative anaerobes had a major relative abundance in the inlet part of the reactor, where the sulfide to oxygen ratio is higher.

  10. New 5-benzylidenethiazolidin-4-one inhibitors of bacterial MurD ligase: design, synthesis, crystal structures, and biological evaluation.

    Science.gov (United States)

    Zidar, Nace; Tomašić, Tihomir; Šink, Roman; Kovač, Andreja; Patin, Delphine; Blanot, Didier; Contreras-Martel, Carlos; Dessen, Andréa; Premru, Manica Müller; Zega, Anamarija; Gobec, Stanislav; Mašič, Lucija Peterlin; Kikelj, Danijel

    2011-11-01

    Mur ligases (MurC-MurF), a group of bacterial enzymes that catalyze four consecutive steps in the formation of cytoplasmic peptidoglycan precursor, are becoming increasingly adopted as targets in antibacterial drug design. Based on the crystal structure of MurD cocrystallized with thiazolidine-2,4-dione inhibitor I, we have designed, synthesized, and evaluated a series of improved glutamic acid containing 5-benzylidenerhodanine and 5-benzylidenethiazolidine-2,4-dione inhibitors of MurD with IC(50) values up to 28 μM. Inhibitor 37, with an IC(50) of 34 μM, displays a weak antibacterial activity against S. aureus ATCC 29213 and E. faecalis ATCC 29212 with minimal inhibitory concentrations of 128 μg/mL. High-resolution crystal structures of MurD in complex with two new inhibitors (compounds 23 and 51) reveal details of their binding modes within the active site and provide valuable information for further structure-based optimization. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  11. Phenotypic resistance and the dynamics of bacterial escape from phage control

    DEFF Research Database (Denmark)

    Bull, James J.; Vegge, Christina Skovgaard; Schmerer, Matthew

    2014-01-01

    The canonical view of phage - bacterial interactions in dense, liquid cultures is that the phage will eliminate most of the sensitive cells; genetic resistance will then ascend to restore high bacterial densities. Yet there are various mechanisms by which bacteria may remain sensitive to phages...... mathematical models of these processes and suggest how different types of this 'phenotypic' resistance may be elucidated. We offer preliminary in vitro studies of a previously characterized E. coli model system and Campylobacter jejuni illustrating apparent phenotypic resistance. As phenotypic resistance may...

  12. Dynamics of bacterial communities before and after distribution in a full-scale drinking water network

    KAUST Repository

    El Chakhtoura, Joline; Prest, Emmanuelle I E C; Saikaly, Pascal; van Loosdrecht, Mark C.M.; Hammes, Frederik A.; Vrouwenvelder, Johannes S.

    2015-01-01

    Understanding the biological stability of drinking water distribution systems is imperative in the framework of process control and risk management. The objective of this research was to examine the dynamics of the bacterial community during

  13. Biological control of fruit-tree red spider mite

    NARCIS (Netherlands)

    Rabbinge, R.

    1976-01-01

    During the last decade, integrated pest control systems have been developed for several crops. One of the main fields of research in integrated control has been the control of orchard pests. Experience with modified spraying programmes in apple orchards, the increasing resistance of spider

  14. The biological control as a strategy to support nontraditional agricultural exports in Peru: An empirical analysis

    Directory of Open Access Journals (Sweden)

    Franklin Duarte Cueva

    2012-12-01

    Full Text Available The study is oriented to explore the general characteristics of agriculture, the biological control as a pest control mechanism and agro export industry. In this context, we try to promote the use of biological control as a strategy to support nontraditional exports related to products such as asparagus and fresh avocados grown in the La Libertad Department (Peru, through an agronomic and management approach. Biological control is the basis of integrated pest management (IPM and contributes to the conservation of agricultural ecosystems allowing to export companies reduce costs, fulfill international phytosanitary measures and supports the preservation of the environment and health. Thus, the Peruvian agro export companies could build a sustainable competitive advantage and seek a positioning as socially responsible firms. We analyze variables such as crop statistics, comparative costs between biological control and chemical control, main destination markets for asparagus and fresh avocados, international standards, among others.

  15. Effect of a Bacterial Grass Culture on the Plant Growth and Disease Control in Tomato

    Directory of Open Access Journals (Sweden)

    Yong Seong Lee

    2017-12-01

    Full Text Available This study aimed to investigate the plant growth-promoting and biocontrol potential of a grass culture with Paenibacillus ehimensis KWN8 on tomato. For this experiment, treatments of a chemical fertilizer (F, a bacterial grass culture (G, a 1/3 volume of G plus 2/3 F (GF, and F plus a synthetic fungicide (FSf were applied to tomato leaves and roots. The result showed that the severity of Alternariasolani and Botrytiscinerea symptoms were significantly reduced after the application of the bacterial grass culture (G and GF and FSf. In addition, root mortality in G and GF was lower compared to F. Tomato plants treated with G or GF had better vegetative growth and yield compared to F. Application of G affected the fungal and bacterial populations in the soil. In conclusion, treatment with a bacterial grass culture decreased disease severity and increased tomato growth parameters. However, there were no statistically significant correlations between disease occurrence and tomato yields. This experiment presents the possibility to manage diseases of tomato in an environmentally friendly manner and to also increase the yield of tomato by using a grass culture broth containing P. ehimensis KWN38.

  16. Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

    Directory of Open Access Journals (Sweden)

    Gilvaine Ciavareli Lucas

    2012-03-01

    Full Text Available The objective of this work was to evaluate the effects of plant essential oils (EOs on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings under greenhouse conditions. The effects of citronella, lemongrass, clove, and tea tree EOs, at 0.1%, on X. vesicatoria cells were evaluated by transmission electron microscopy. All EOs showed direct toxic effect on the bacteria at a 10%-concentration in vitro. Under greenhouse conditions, the EOs of clove, citronella, tea tree, and lemongrass reduced disease severity. EOs of clove and tea tree, and streptomycin sulfate promoted loss of electron-dense material and alterations in the cytoplasm, whereas EO of tea tree promoted cytoplasm vacuolation, and those of citronella, lemongrass, clove, and tea tree caused damage to the bacterial cell wall. The EOs at a concentration of 0.1% reduce the severity of the disease.

  17. Differences in bacterial saliva profile between periodontitis patients and a control cohort

    DEFF Research Database (Denmark)

    Belstrøm, Daniel; Fiehn, Nils-Erik; Nielsen, Claus H

    2014-01-01

    AIM: Periodontitis is a multifactorial disease in which subgingival bacteria play an important role in the pathogenesis of the disease. The objective of this study was to determine if periodontitis is associated with a characteristic salivary bacterial profile. This was accomplished by comparing ...

  18. Organization and Biology of the Porcine Serum Amyloid A (SAA) Gene Cluster: Isoform Specific Responses to Bacterial Infection

    DEFF Research Database (Denmark)

    Olsen, Helle G; Skovgaard, Kerstin; Nielsen, Ole L

    2013-01-01

    Serum amyloid A (SAA) is a prominent acute phase protein. Although its biological functions are debated, the wide species distribution of highly homologous SAA proteins and their uniform behavior in response to injury or inflammation in itself suggests a significant role for this protein. The pig...... is increasingly being used as a model for the study of inflammatory reactions, yet only little is known about how specific SAA genes are regulated in the pig during acute phase responses and other responses induced by pro-inflammatory host mediators. We designed SAA gene specific primers and quantified the gene...... expression of porcine SAA1, SAA2, SAA3, and SAA4 by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in liver, spleen, and lung tissue from pigs experimentally infected with the Gram-negative swine specific bacterium Actinobacillus pleuropneumoniae, as well as from pigs experimentally...

  19. Biological control of vaginosis to improve reproductive health

    Directory of Open Access Journals (Sweden)

    P Mastromarino

    2014-01-01

    Full Text Available The human vaginal microbiota plays an important role in the maintenance of a woman′s health, as well as of her partner′s and newborns′. When this predominantly Lactobacillus community is disrupted, decreased in abundance and replaced by different anaerobes, bacterial vaginosis (BV may occur. BV is associated with ascending infections and obstetrical complications, such as chorioamnionitis and preterm delivery, as well as with urinary tract infections and sexually transmitted infections. In BV the overgrowth of anaerobes produces noxious substances like polyamines and other compounds that trigger the release of pro-inflammatory cytokines interleukin (IL-1 β and IL-8. BV can profoundly affect, with different mechanisms, all the phases of a woman′s life in relation to reproduction, before pregnancy, during fertilization, through and at the end of pregnancy. BV can directly affect fertility, since an ascending dissemination of the involved species may lead to tubal factor infertility. Moreover, the increased risk of acquiring sexually transmitted diseases contributes to damage to reproductive health. Exogenous strains of lactobacilli have been suggested as a means of re-establishing a normal healthy vaginal flora. Carefully selected probiotic strains can eliminate BV and also exert an antiviral effect, thus reducing viral load and preventing foetal and neonatal infection. The administration of beneficial microorganisms (probiotics can aid recovery from infection and restore and maintain a healthy vaginal ecosystem, thus improving female health also in relation to reproductive health.

  20. Enhancing biological control of basal stem rot disease (Ganoderma boninense) in oil palm plantations.

    Science.gov (United States)

    Susanto, A; Sudharto, P S; Purba, R Y

    2005-01-01

    Basal Stem Rot (BSR) disease caused by Ganoderma boninense is the most destructive disease in oil palm, especially in Indonesia and Malaysia. The available control measures for BSR disease such as cultural practices and mechanical and chemical treatment have not proved satisfactory due to the fact that Ganoderma has various resting stages such as melanised mycelium, basidiospores and pseudosclerotia. Alternative control measures to overcome the Ganoderma problem are focused on the use of biological control agents and planting resistant material. Present studies conducted at Indonesian Oil Palm Research Institute (IOPRI) are focused on enhancing the use of biological control agents for Ganoderma. These activities include screening biological agents from the oil palm rhizosphere in order to evaluate their effectiveness as biological agents in glasshouse and field trials, testing their antagonistic activities in large scale experiments and eradicating potential disease inoculum with biological agents. Several promising biological agents have been isolated, mainly Trichoderma harzianum, T. viride, Gliocladium viride, Pseudomonas fluorescens, and Bacillus sp. A glasshouse and field trial for Ganoderma control indicated that treatment with T. harzianum and G. viride was superior to Bacillus sp. A large scale trial showed that the disease incidence was lower in a field treated with biological agents than in untreated fields. In a short term programme, research activities at IOPRI are currently focusing on selecting fungi that can completely degrade plant material in order to eradicate inoculum. Digging holes around the palm bole and adding empty fruit bunches have been investigated as ways to stimulate biological agents.

  1. Complete Host Range Testing on Common Reed with Potential Biological Control Agents and Investigation into Biological Control for Flowering Rush

    Science.gov (United States)

    2016-07-01

    CR-16-5 v Preface This report was prepared by Drs. Patrick Häfliger and Hariet Hinz, Centre for Agriculture and Bioscience International (CABI...through Cornell University, the Washington Department of Agriculture , the Washington Department of Ecology, the Washington Department of Natural...capacity during biological invasion in an aquatic plant Butomus umbellatus (Butomaceae). American Journal of Botany 92:495–502. Dieckmann, L. 1983

  2. Anaerobic Digestion. Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Carnegie, John W., Ed.

    This student manual contains the textual material for a four-lesson unit on anaerobic digestion control. Areas addressed include: (1) anaerobic sludge digestion (considering the nature of raw sludge, purposes of anaerobic digestion, the results of digestion, types of equipment, and other topics); (2) digester process control (considering feeding…

  3. Identification and Characterization of Novel Biocontrol Bacterial

    Directory of Open Access Journals (Sweden)

    Young Cheol Kim

    2014-09-01

    Full Text Available Because bacterial isolates from only a few genera have been developed commercially as biopesticides, discovery and characterization of novel bacterial strains will be a key to market expansion. Our previous screen using plant bioassays identified 24 novel biocontrol isolates representing 12 different genera. In this study, we characterized the 3 isolates showing the best biocontrol activities. The isolates were Pantoea dispersa WCU35, Proteus myxofaciens WCU244, and Exiguobacterium acetylicum WCU292 based on 16S rRNA sequence analysis. The isolates showed differential production of extracellular enzymes, antimicrobial activity against various fungal or bacterial plant pathogens, and induced systemic resistance activity against tomato gray mold disease caused by Botrytis cinerea. E. acetylicum WCU292 lacked strong in vitro antimicrobial activity against plant pathogens, but induced systemic resistance against tomato gray mold disease. These results confirm that the trait of biological control is found in a wide variety of bacterial genera

  4. The Mineralosphere Concept: Mineralogical Control of the Distribution and Function of Mineral-associated Bacterial Communities.

    Science.gov (United States)

    Uroz, Stephane; Kelly, Laura Catherine; Turpault, Marie-Pierre; Lepleux, Cendrella; Frey-Klett, Pascale

    2015-12-01

    Soil is composed of a mosaic of different rocks and minerals, usually considered as an inert substrata for microbial colonization. However, recent findings suggest that minerals, in soils and elsewhere, favour the development of specific microbial communities according to their mineralogy, nutritive content, and weatherability. Based upon recent studies, we highlight how bacterial communities are distributed on the surface of, and in close proximity to, minerals. We also consider the potential role of the mineral-associated bacterial communities in mineral weathering and nutrient cycling in soils, with a specific focus on nutrient-poor and acidic forest ecosystems. We propose to define this microbial habitat as the mineralosphere, where key drivers of the microbial communities are the physicochemical properties of the minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. First controlled vertical flight of a biologically inspired microrobot

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Arancibia, Nestor O; Ma, Kevin Y; Greenberg, Jack D; Wood, Robert J [School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138 (United States); Galloway, Kevin C, E-mail: nperez@seas.harvard.edu, E-mail: kevinma@seas.harvard.edu, E-mail: kevin.galloway@wyss.harvard.edu, E-mail: jdgreenb@seas.harvard.edu, E-mail: rjwood@eecs.harvard.edu [Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115 (United States)

    2011-09-15

    In this paper, we present experimental results on altitude control of a flying microrobot. The problem is approached in two stages. In the first stage, system identification of two relevant subsystems composing the microrobot is performed, using a static flapping experimental setup. In the second stage, the information gathered through the static flapping experiments is employed to design the controller used in vertical flight. The design of the proposed controller relies on the idea of treating an exciting signal as a subsystem of the microrobot. The methods and results presented here are a key step toward achieving total autonomy of bio-inspired flying microrobots.

  6. First controlled vertical flight of a biologically inspired microrobot

    International Nuclear Information System (INIS)

    Perez-Arancibia, Nestor O; Ma, Kevin Y; Greenberg, Jack D; Wood, Robert J; Galloway, Kevin C

    2011-01-01

    In this paper, we present experimental results on altitude control of a flying microrobot. The problem is approached in two stages. In the first stage, system identification of two relevant subsystems composing the microrobot is performed, using a static flapping experimental setup. In the second stage, the information gathered through the static flapping experiments is employed to design the controller used in vertical flight. The design of the proposed controller relies on the idea of treating an exciting signal as a subsystem of the microrobot. The methods and results presented here are a key step toward achieving total autonomy of bio-inspired flying microrobots.

  7. Biological control and management of the detoxication wastewater treatment technologies

    Directory of Open Access Journals (Sweden)

    Topalova Yana

    2007-01-01

    Full Text Available Detoxication technologies require the combination of theoretical and practical knowledge of xenobiotic biodegradation, wastewater treatment technologies, and management rules. The purpose of this complicated combination is to propose specialized strategies for detoxication, based on lab- and pilot-scale modeling. These strategies include preliminary created algorithms for preventing the risk of water pollution and sediments. The technologies and algorithms are essentially important outcome, applied in the textile, pharmaceutical, cosmetic, woodtreating, and oiltreating industries. In this paper four rehabilitation technologies for pretreatment of water contaminated by pentachlorophenol (PCP have been developed in the frame of the European and Bulgarian National projects. Emphasize is put on the biological systems and their potential of detoxication management. The light and transmission electron microscopy of the reconstructed activated sludges the microbial, kinetic and enzymological indicators are presented and approved as critical points in the biocontrol.

  8. SOME ASPECTS OF THE BIOLOGY AND CONTROL OF ...

    African Journals Online (AJOL)

    Key Words: Callosobruchus maculatus, developmental period, soya bean, Azadirachta indica, Citrus sinensis. ASPECTS DE LA BIOLOGIE ET DU CONTROLE DU CALLOSOBRUCHUS MACULATUS (F.) SUR LA CONSERVATION DES GRAINES DE SOJA DES VARIETES GLYCINE MAX (L.) MERR NOTE DE SYNTHESE

  9. Spatiotemporal variation of bacterial community composition and possible controlling factors in tropical shallow lagoons.

    Science.gov (United States)

    Laque, Thaís; Farjalla, Vinicius F; Rosado, Alexandre S; Esteves, Francisco A

    2010-05-01

    Bacterial community composition (BCC) has been extensively related to specific environmental conditions. Tropical coastal lagoons present great temporal and spatial variation in their limnological conditions, which, in turn, should influence the BCC. Here, we sought for the limnological factors that influence, in space and time, the BCC in tropical coastal lagoons (Rio de Janeiro State, Brazil). The Visgueiro lagoon was sampled monthly for 1 year and eight lagoons were sampled once for temporal and spatial analysis, respectively. BCC was evaluated by bacteria-specific PCR-DGGE methods. Great variations were observed in limnological conditions and BCC on both temporal and spatial scales. Changes in the BCC of Visgueiro lagoon throughout the year were best related to salinity and concentrations of NO (3) (-) , dissolved phosphorus and chlorophyll-a, while changes in BCC between lagoons were best related to salinity and dissolved phosphorus concentration. Salinity has a direct impact on the integrity of the bacterial cell, and it was previously observed that phosphorus is the main limiting nutrient to bacterial growth in these lagoons. Therefore, we conclude that great variations in limnological conditions of coastal lagoons throughout time and space resulted in different BCCs and salinity and nutrient concentration, particularly dissolved phosphorus, are the main limnological factors influencing BCC in these tropical coastal lagoons.

  10. Bacterial microflora of poultry feed and its control by gamma irradiation

    International Nuclear Information System (INIS)

    El-Zawahry, Y.A.; Youssef, Y.A.; Roushdy, H.M.; Aziz, N.H.

    1986-01-01

    The common bacteria isolated from the poultry feed samples were classified in the families of Pseudomonadaceae, Micrococcacae, Bacililaceae and Enterobacteriaceae. These species of bacteria were identified as 10 species of Gram-negative and 13 species of Gram-positive. We found that radiation dose required to inhibit completely the natural bacterial flora in tested samples of poultry feed was 20 KGY. The most radioresistant bacterial isolates which resisted a sublethal dose of 15 KGY were identified as bacillus cereus, Bacillus polymxa and Bacillus megaterium. The dose response curves of B, cereus and B, polymxa started by shoulder portion followed by an exponential death, whereas, B, megaterium exhibited straight line relationship directly. The D 10 -value of B. megaterium spores (3.30 KGY) was about 1.5 and 1.7 folds as the D 10 value B. polymxa and B, cereus, respectively. The present work indicated also that the exposure of poultry feed to irradiation dose 10 KGY (1 Mrad) reduced greatly number of bacteria destroyed all spoilage and pathogenic bacteria especially Salmonella, and finally increased the shelf-life during storage periods. Higher radiation dose 15 KGY, failed to show any better reduction of viable bacterial counts. Part of this work presented in (FAO/IAEA) international symposium for food irradiation processing, Washington, D.C., U.S.A. (4-8 March, 1985)

  11. Biological control of schistosome transmission in flowing water habitats.

    Science.gov (United States)

    Jobin, W R; Laracuente, A

    1979-09-01

    Marisa cornuarietis was evaluated in Puerto Rico for control of schistosome transmission in flowing water. A population of Biomphalaria glabrata and their schistosome infections disappeared after introduction of 20,000 M. cornuarietis to an endemic stream, while in nearby untreated streams the B. glabrata population remained stable and the schistosome prevalence increased. This method cost U.S. $0.10 per capita for over a year of protection, 5%-10% of the cost of chemical control.

  12. [Bacterial contamination of mobile phones shared in hospital wards and the consciousness and behavior of nurses about biological cleanliness].

    Science.gov (United States)

    Morioka, Ikuharu; Tabuchi, Yuna; Takahashi, Yuko; Oda, Yuriko; Nakai, Masami; Yanase, Aki; Watazu, Chiyoko

    2011-01-01

    The purpose of this study was to clarify the contamination of mobile phones shared in hospital wards and its relationship with the consciousness and behavior of nurses about biological cleanliness. Samples from mobile phones were cultured to detect viable bacteria (n=110) and Staphylococcus aureus (n=54). A questionnaire survey was conducted on 110 nurses carrying mobile phones on the day of sampling. Viable bacteria were detected on 79.1% of the mobile phones, whereas S. aureus was detected on 68.6%. All the nurses were aware of hand washing with water or alcohol after regular work, but 33.6% of the nurses were not conscious of hand washing with water or alcohol after using a mobile phone. There was a significant positive relationship between the frequency of using mobile phones and the number of hand washings with water or alcohol. A significant negative relationship was found between the detection of viable bacteria and the number of hand washings with alcohol. The results of logistic regression analysis showed that the detection of viable bacteria was related significantly with the number of hand washings with alcohol (Odds ratio, 0.350; 95%CI, 0.143-0.857) and that the detection of S. aureus was related significantly with the frequency of using mobile phones (Odds ratio, 0.183; 95%CI, 0.036-0.933). It is important to be conscious of the fact that mobile phones shared in hospital wards are easily contaminated. Because hand washing with water or alcohol prevents the contamination of the mobile phones, nurses should take standard precautions after using mobile phones.

  13. Whole-genome sequencing of Bacillus subtilis XF-1 reveals mechanisms for biological control and multiple beneficial properties in plants.

    Science.gov (United States)

    Guo, Shengye; Li, Xingyu; He, Pengfei; Ho, Honhing; Wu, Yixin; He, Yueqiu

    2015-06-01

    Bacillus subtilis XF-1 is a gram-positive, plant-associated bacterium that stimulates plant growth and produces secondary metabolites that suppress soil-borne plant pathogens. In particular, it is especially highly efficient at controlling the clubroot disease of cruciferous crops. Its 4,061,186-bp genome contains an estimated 3853 protein-coding sequences and the 1155 genes of XF-1 are present in most genome-sequenced Bacillus strains: 3757 genes in B. subtilis 168, and 1164 in B. amyloliquefaciens FZB42. Analysis using the Cluster of Orthologous Groups database of proteins shows that 60 genes control bacterial mobility, 221 genes are related to cell wall and membrane biosynthesis, and more than 112 are genes associated with secondary metabolites. In addition, the genes contributed to the strain's plant colonization, bio-control and stimulation of plant growth. Sequencing of the genome is a fundamental step for developing a desired strain to serve as an efficient biological control agent and plant growth stimulator. Similar to other members of the taxon, XF-1 has a genome that contains giant gene clusters for the non-ribosomal synthesis of antifungal lipopeptides (surfactin and fengycin), the polyketides (macrolactin and bacillaene), the siderophore bacillibactin, and the dipeptide bacilysin. There are two synthesis pathways for volatile growth-promoting compounds. The expression of biosynthesized antibiotic peptides in XF-1 was revealed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry.

  14. Differential physiological responses of dalmatian toadflax, Linaria dalmatica L. Miller, to injury from two insect biological control agents: Implications for decision-making in biological control

    Science.gov (United States)

    Robert K. D. Peterson; Sharlene E. Sing; David K. Weaver

    2005-01-01

    Successful biological control of invasive weeds with specialist herbivorous insects is predicated on the assumption that the injury stresses the weeds sufficiently to cause reductions in individual fitness. Because plant gas exchange directly impacts growth and fitness, characterizing how injury affects these primary processes may provide a key indicator of...

  15. Green and brown propolis: efficient natural biocides for the control of bacterial contamination of alcoholic fermentation of distilled beverage

    Directory of Open Access Journals (Sweden)

    Márcia Justino Rossini Mutton

    2014-12-01

    Full Text Available This study aimed to evaluate the efficiency of natural biocides, brown and green propolis, for the control of bacterial contamination in the production of sugarcane spirit. The treatments consisted of brown and green propolis extracts, ampicillin, and a control and were assessed at the beginning and end of harvest season in ten fermentation cycles. In the microbiological analyses, the lactic acid bacteria were quantified in the inoculum before and after the treatment with biocides, and the viability of yeast cells during fermentation was evaluated. The levels of acids, glycerol, total residual reducing sugars, and ethanol were analyzed for the wine resulting from each fermentation cycle. A reduction in the number of bacterial contaminants in the inoculum in the treatments with the natural biocides was observed, but it did not affect the viability of yeast cells. The control of the contaminants led to the production of higher levels of ethanol and reduced acidity in the wine produced. The results of the use of brown and green propolis to control the growth microorganisms in the fermentation of sugarcane spirit can be of great importance for using alternative strategies to synthetic antibacterials in fermentation processes including other distilled beverage or spirits.

  16. Do biological-based strategies hold promise to biofouling control in MBRs?

    KAUST Repository

    Malaeb, Lilian; Le-Clech, Pierre; Vrouwenvelder, Johannes S.; Ayoub, George M.; Saikaly, Pascal

    2013-01-01

    . The reason for the slow advancement in successful control of biofouling is largely attributed to the complex interactions of involved biological compounds and the lack of representative-for-practice experimental approaches to evaluate potential effective

  17. Holarchical Systems and Emotional Holons : Biologically-Inspired System Designs for Control of Autonomous Aerial Vehicles

    Science.gov (United States)

    Ippolito, Corey; Plice, Laura; Pisanich, Greg

    2003-01-01

    The BEES (Bio-inspired Engineering for Exploration Systems) for Mars project at NASA Ames Research Center has the goal of developing bio-inspired flight control strategies to enable aerial explorers for Mars scientific investigations. This paper presents a summary of our ongoing research into biologically inspired system designs for control of unmanned autonomous aerial vehicle communities for Mars exploration. First, we present cooperative design considerations for robotic explorers based on the holarchical nature of biological systems and communities. Second, an outline of an architecture for cognitive decision making and control of individual robotic explorers is presented, modeled after the emotional nervous system of cognitive biological systems. Keywords: Holarchy, Biologically Inspired, Emotional UAV Flight Control

  18. Biological control of saltcedar (Tamarix spp.) by saltcedar leaf beetles (Diorhabda spp.): effects on small mammals

    Science.gov (United States)

    The spread of introduced saltcedar (Tamarix spp.) throughout many riparian systems across the western United States motivated the introduction of biological control agents that are specific to saltcedar, saltcedar leaf beetles (Diorhabda carinulata, D. elongata; Chrysomelidae). I monitored small mam...

  19. Costs and benefits of biological control of invasive alien plants: case studies from South Africa

    CSIR Research Space (South Africa)

    Van Wilgen, BW

    2004-01-01

    Full Text Available Invasive alien species can have significant negative environmental and economic impacts. Such species are often controlled biologically by means of introducing host-specific insects or pathogens that can reduce the species' invasive potential...

  20. Parasitoids attacking emerald ash borers in western Pennsylvania and their potential use in biological control

    Science.gov (United States)

    J.J. Duan; R.W. Fuester; J. Wildonger; P.B. Taylor; S. Barth; S-E. Spichiger

    2009-01-01

    Current biological control programs against the emerald ash borer (EAB, Agrilus planipennis Fairmaire) have primarily focused on the introduction and releases of exotic parasitoids from China, home of the pest origin....

  1. Biological control of toxic cyanobacteria by mixotrophic predators: an experimental test of intraguild predation theory

    NARCIS (Netherlands)

    Wilken, S.; Verspagen, J.M.H.; Naus-Wiezer, S.M.H.; Van Donk, E.; Huisman, Jef

    2014-01-01

    Intraguild predators both feed on and compete with their intraguild prey. In theory, intraguild predators can therefore be very effective as biological control agents of intraguild prey species, especially in productive environments. We investigated this hypothesis using the mixotrophic chrysophyte

  2. Biological control of banana black Sigatoka disease with Trichoderma

    Directory of Open Access Journals (Sweden)

    Poholl Adan Sagratzki Cavero

    2015-06-01

    Full Text Available Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both field experiments and was selected for fungicide sensitivity tests and mass production. This isolate was identified as Trichoderma atroviride by sequencing fragments of the ITS region of the rDNA and tef-1α of the RNA polymerase. Trichoderma atroviride was as effective as the fungicide Azoxystrobin, which is recommended for controlling black Sigatoka. This biocontrol agent has potential to control the disease and may be scaled-up for field applications on rice-based solid fermentation

  3. Interferon Lambda Genetics and Biology in Regulation of Viral Control

    Directory of Open Access Journals (Sweden)

    Emily A. Hemann

    2017-12-01

    Full Text Available Type III interferons, also known as interferon lambdas (IFNλs, are the most recent addition to the IFN family following their discovery in 2003. Initially, IFNλ was demonstrated to induce expression of interferon-stimulated genes and exert antiviral properties in a similar manner to type I IFNs. However, while IFNλ has been described to have largely overlapping expression and function with type I IFNs, it has become increasingly clear that type III IFNs also have distinct functions from type I IFNs. In contrast to type I IFNs, whose receptor is ubiquitously expressed, type III IFNs signal and function largely at barrier epithelial surfaces, such as the respiratory and gastrointestinal tracts, as well as the blood–brain barrier. In further support of unique functions for type III IFNs, single nucleotide polymorphisms in IFNL genes in humans are strongly associated with outcomes to viral infection. These biological linkages have also been more directly supported by studies in mice highlighting roles of IFNλ in promoting antiviral immune responses. In this review, we discuss the current understanding of type III IFNs, and how their functions are similar to, and different from, type I IFN in various immune cell subtypes and viral infections.

  4. The biological basis for the control of prenatal irradiation

    International Nuclear Information System (INIS)

    1988-01-01

    The embryo and fetus have been generally considered to be more sensitive than the adult to the detrimental effects of radiation exposure. In particular, recent re-evaluations of epidemiological data on human population exposed to radiation have suggested that there may be greater sensitivity than heretofore recognized to the induction of mental retardation and reduced intelligence by exposure during gestation. To assist national authorities in evaluating this problem and establishing appropriate protection measures for limiting the dose to the embryo and fetus and, thus, to pregnant or potentially pregnant women, the Nuclear Energy Agency has appointed a Group of Consultants to assemble and evaluate the biological data relevant to the protection of the human conceptus, and to make recommendations for achieving this in the operational practice. The Group has surveyed the human data dealing with the biologcal effects of radiation exposure at low doses, and has supplemented this with information derived from animal studies. The Group has also taken full account of the studies and recommendations issued in this area by other international organizations, primarily the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the International Commission on Radiological Protection (ICRP). This report is published under the responsibility of the Secretary General of the OECD, and does not commit Member governments of the Organization

  5. Biology and control of the raspberry crown borer (Lepidoptera: Sesiidae).

    Science.gov (United States)

    McKern, Jacquelyn A; Johnson, Donn T; Lewis, Barbara A

    2007-04-01

    This study explored the biology of raspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera: Sesiidae), in Arkansas and the optimum timing for insecticide and nematode applications. The duration of P. marginata's life cycle was observed to be 1 yr in Arkansas. Insecticide trials revealed that bifenthrin, chlorpyrifos, imidacloprid, metaflumizone, and metofluthrin efficacy were comparable with that of azinphosmethyl, the only labeled insecticide for P. marginata in brambles until 2005. Applications on 23 October 2003 for plots treated with bifenthrin, chlorpyrifos, and azinphosmethyl resulted in >88% reduction in larvae per crown. Applications on 3 November 2004 of metaflumizone, metofluthrin, and bifenthrin resulted in >89% reduction in larvae per crown. Applications on 7 April 2005 for metofluthrin, imidacloprid, bifenthrin, metaflumizone, and benzoylphenyl urea resulted in >64% reduction in the number of larvae per crown. Applications on 6 May 2004 did not reduce larval numbers. The optimum timing for treatments was found to be between October and early April, before the larvae tunneled into the crowns of plants. Applying bifenthrin with as little as 468 liters water/ha (50 gal/acre) was found to be as effective against larvae as higher volumes of spray. Nematode applications were less successful than insecticides. Nematode applications of Steinernemafeltiae, Steinernema carpocapsae, and Heterorhabditis bacteriophora reduced larvae counts per plant by 46, 53, and 33%, respectively.

  6. Anaerobic Digestion. Instructor's Guide. Biological Treatment Process Control.

    Science.gov (United States)

    Carnegie, John W., Ed.

    This instructor's guide contains materials needed to teach a four-lesson unit on anaerobic digestion control. These materials include: (1) unit overview; (2) lesson plans; (3) lecture outlines; (4) student worksheets for each lesson (with answers); and (5) two copies of a final quiz (with and without answers). Lesson 1 is a review of the theory of…

  7. Ecological risks of biological control agents: impacts on IPM

    NARCIS (Netherlands)

    Hokkanen, H.M.T.; Lenteren, van J.C.; Menzler-Hokkanen, I.

    2007-01-01

    Since the early days of integrated pest management a sound ecological foundation has been considered essential for the development of effective systems. From time to time, there have been attempts to evaluate the ways in which ecological theory is exploited in pest control, and to review the lessons

  8. Comparison between chemical and biological control of Fusarium ...

    African Journals Online (AJOL)

    ... College of Education, Jeddah, Saudi Arabia. The results revealed that treatment with the fungicide carbomar or T. harzianum as well as with B. subtilis, in presence of F. solani increased the % of healthy seedlings as well as their length , fresh and dry weight than in presence of F. solani alone but still less than the control.

  9. Identifying Ant-Mirid Spatial Interactions to Improve Biological Control in Cacao-Based Agroforestry System.

    Science.gov (United States)

    Bagny Beilhe, Leïla; Piou, Cyril; Tadu, Zéphirin; Babin, Régis

    2018-06-06

    The use of ants for biological control of insect pests was the first reported case of conservation biological control. Direct and indirect community interactions between ants and pests lead to differential spatial pattern. We investigated spatial interactions between mirids, the major cocoa pest in West Africa and numerically dominant ant species, using bivariate point pattern analysis to identify potential biological control agents. We assume that potential biological control agents should display negative spatial interactions with mirids considering their niche overlap. The mirid/ant data were collected in complex cacao-based agroforestry systems sampled in three agroecological areas over a forest-savannah gradient in Cameroon. Three species, Crematogaster striatula Emery (Hymenoptera: Formicidae), Crematogaster clariventris Mayr (Hymenoptera: Formicidae), and Oecophylla longinoda Latreille (Hymenoptera: Formicidae) with high predator and aggressive behaviors were identified as dominant and showed negative spatial relationships with mirids. The weaver ant, O. longinoda was identified as the only potential biological control agent, considering its ubiquity in the plots, the similarity in niche requirements, and the spatial segregation with mirids resulting probably from exclusion mechanisms. Combining bivariate point pattern analysis to good knowledge of insect ecology was an effective method to identify a potentially good biological control agent.

  10. A biologically inspired neural network controller for ballistic arm movements

    Directory of Open Access Journals (Sweden)

    Schmid Maurizio

    2007-09-01

    Full Text Available Abstract Background In humans, the implementation of multijoint tasks of the arm implies a highly complex integration of sensory information, sensorimotor transformations and motor planning. Computational models can be profitably used to better understand the mechanisms sub-serving motor control, thus providing useful perspectives and investigating different control hypotheses. To this purpose, the use of Artificial Neural Networks has been proposed to represent and interpret the movement of upper limb. In this paper, a neural network approach to the modelling of the motor control of a human arm during planar ballistic movements is presented. Methods The developed system is composed of three main computational blocks: 1 a parallel distributed learning scheme that aims at simulating the internal inverse model in the trajectory formation process; 2 a pulse generator, which is responsible for the creation of muscular synergies; and 3 a limb model based on two joints (two degrees of freedom and six muscle-like actuators, that can accommodate for the biomechanical parameters of the arm. The learning paradigm of the neural controller is based on a pure exploration of the working space with no feedback signal. Kinematics provided by the system have been compared with those obtained in literature from experimental data of humans. Results The model reproduces kinematics of arm movements, with bell-shaped wrist velocity profiles and approximately straight trajectories, and gives rise to the generation of synergies for the execution of movements. The model allows achieving amplitude and direction errors of respectively 0.52 cm and 0.2 radians. Curvature values are similar to those encountered in experimental measures with humans. The neural controller also manages environmental modifications such as the insertion of different force fields acting on the end-effector. Conclusion The proposed system has been shown to properly simulate the development of

  11. Bacteriophage-Based Bacterial Wilt Biocontrol for an Environmentally Sustainable Agriculture

    OpenAIRE

    ?lvarez, Bel?n; Biosca, Elena G.

    2017-01-01

    Bacterial wilt diseases caused by Ralstonia solanacearum, R. pseudosolanacearum, and R. syzygii subsp. indonesiensis (former R. solanacearum species complex) are among the most important plant diseases worldwide, severely affecting a high number of crops and ornamentals. Difficulties of bacterial wilt control by non-biological methods are related to effectiveness, bacterial resistance and environmental impact. Alternatively, a great many biocontrol strategies have been carried out, with the a...

  12. Relative Abundance in Bacterial and Fungal Gut Microbes in Obese Children: A Case Control Study.

    Science.gov (United States)

    Borgo, Francesca; Verduci, Elvira; Riva, Alessandra; Lassandro, Carlotta; Riva, Enrica; Morace, Giulia; Borghi, Elisa

    2017-02-01

    Differences in relative proportions of gut microbial communities in adults have been correlated with intestinal diseases and obesity. In this study we evaluated the gut microbiota biodiversity, both bacterial and fungal, in obese and normal-weight school-aged children. We studied 28 obese (mean age 10.03 ± 0.68) and 33 age- and sex-matched normal-weight children. BMI z-scores were calculated, and the obesity condition was defined according to the WHO criteria. Fecal samples were analyzed by 16S rRNA amplification followed by denaturing gradient gel electrophoresis (DGGE) analysis and sequencing. Real-time polymerase chain reaction (PCR) was performed to quantify the most representative microbial species and genera. DGGE profiles showed high bacterial biodiversity without significant correlations with BMI z-score groups. Compared to bacterial profiles, we observed lower richness in yeast species. Sequence of the most representative bands gave back Eubacterium rectale, Saccharomyces cerevisiae, Candida albicans, and C. glabrata as present in all samples. Debaryomyces hansenii was present only in two obese children. Obese children revealed a significantly lower abundance in Akkermansia muciniphyla, Faecalibacterium prausnitzii, Bacteroides/Prevotella group, Candida spp., and Saccharomyces spp. (P = 0.031, P = 0.044, P = 0.003, P = 0.047, and P = 0.034, respectively). Taking into account the complexity of obesity, our data suggest that differences in relative abundance of some core microbial species, preexisting or diet driven, could actively be part of its etiology. This study improved our knowledge about the fungal population in the pediatric school-age population and highlighted the need to consider the influence of cross-kingdom relationships.

  13. Mechanization and Control Concepts for Biologically Inspired Micro Aerial Vehicles

    Science.gov (United States)

    Raney, David L.; Slominski, Eric C.

    2003-01-01

    It is possible that MAV designs of the future will exploit flapping flight in order to perform missions that require extreme agility, such as rapid flight beneath a forest canopy or within the confines of a building. Many of nature's most agile flyers generate flapping motions through resonant excitation of an aeroelastically tailored structure: muscle tissue is used to excite a vibratory mode of their flexible wing structure that creates propulsion and lift. A number of MAV concepts have been proposed that would operate in a similar fashion. This paper describes an ongoing research activity in which mechanization and control concepts with application to resonant flapping MAVs are being explored. Structural approaches, mechanical design, sensing and wingbeat control concepts inspired by hummingbirds, bats and insects are examined. Experimental results from a testbed capable of generating vibratory wingbeat patterns that approximately match those exhibited by hummingbirds in hover, cruise, and reverse flight are presented.

  14. Biological Control of Mosquito Vectors: Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    Giovanni Benelli

    2016-10-01

    Full Text Available Mosquitoes represent the major arthropod vectors of human disease worldwide transmitting malaria, lymphatic filariasis, and arboviruses such as dengue virus and Zika virus. Unfortunately, no treatment (in the form of vaccines or drugs is available for most of these diseases andvectorcontrolisstillthemainformofprevention. Thelimitationsoftraditionalinsecticide-based strategies, particularly the development of insecticide resistance, have resulted in significant efforts to develop alternative eco-friendly methods. Biocontrol strategies aim to be sustainable and target a range of different mosquito species to reduce the current reliance on insecticide-based mosquito control. In thisreview, weoutline non-insecticide basedstrategiesthat havebeenimplemented orare currently being tested. We also highlight the use of mosquito behavioural knowledge that can be exploited for control strategies.

  15. Computational Biomathematics: Toward Optimal Control of Complex Biological Systems

    Science.gov (United States)

    2016-09-26

    SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS...neighbor or bi-linear interpolation). The following paper is in preparation: Scaling methods and heuristic algorithms for agent-based models. Matt...The actual method of control used is in the form of heuristic algorithms. In general, these algorithms search through a virtually infinite set of

  16. Biological control of banana black Sigatoka disease with Trichoderma

    OpenAIRE

    Poholl Adan Sagratzki Cavero; Rogério Eiji Hanada; Luadir Gasparotto; Rosalee Albuquerque Coelho Neto; Jorge Teodoro de Souza

    2015-01-01

    Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both f...

  17. Hydrologic Control on Bacterial Nitrogen Fixation in the Holocene Black Sea

    Science.gov (United States)

    Fulton, J. M.; Arthur, M. A.; Freeman, K. H.

    2008-12-01

    Stratified oceans of the Phanerozoic Oceanic Anoxic Events apparently were dominated by bacterial nitrogen fixation. Decreased marine N:P nutrient ratios resulting from increased denitrification and decreased phosphate burial efficiency under anoxic waters drove this nutrient regime. This model is upheld by the presence of cyanobacterial hopanoid biomarkers in sedimentary records and δ15N values indicative of nitrogen fixation. However, in the largest modern redox-stratified marine basin, the Black Sea, bacterial nitrogen fixation seems to be only a minor contributor to the nitrogen cycle. In this study, we use geochemical proxies to evaluate the role of bacterial nitrogen fixation during the deposition of the Holocene Black Sea sapropel, starting 7.8 ka. We report compound-specific nitrogen and carbon stable isotope values of pyropheophytin a, a chlorophyll degradation product, and bacteriochlorophyll e produced by green sulfur bacteria. We also present the surprising finding of scytonemin, a pigment produced only by filamentous cyanobacteria exposed to ultraviolet radiation, in certain intervals in these sediments. In the Holocene, nitrogen fixation in the Black Sea is most prominent during times of reduced river water influx. This directly decreases the external flux of nitrate into the surface waters. Reduced freshwater influx also decreases the volume of low salinity water dispersed around the sea by the Rim Current, allowing the chemocline to shoal along the margins. Previous geochemical studies have described this changing chemocline geometry. The exposure of shallow water sediments to anoxic waters further stimulates nitrogen fixation by releasing more phosphorus to the system. Nitrogen fixation is recorded in the sediments as bulk and compound-specific pyropheophytin a δ15N values near 0 ‰ and -5 ‰, respectively. We have also detected scytonemin in two intervals characterized by especially low δ15N values. This compound suggests abundant filamentous

  18. Biological control of Egyptian broomrape (Orobanche aegyptiaca using Fusarium spp.

    Directory of Open Access Journals (Sweden)

    I. Ghannam

    2007-08-01

    Full Text Available The broomrape (Orobanche spp. is an obligate holoparasitic weed that causes severe damage to many important vegetable crops. Many broomrape control strategies have been tested over the years. In this investigation, 125 Fusarium spp. isolates were recovered from diseased broomrape spikes collected from fields in agricultural areas near Hebron. The pathogenicity of isolates on broomrape was evaluated using an inoculum suspension containing mycelia and conidia. The most effective Fusarium isolates significantly increased the dead spikes of broomrape by 33.6–72.7% compared to the control; there was no obvious pathogenic effect on the tomato plants. Fusarium spp. isolates Fu 20, 25 and 119 were identified as F. solani, while Fu 30, 52, 59, 87 and 12-04 were F. oxysporum. In addition, the two previously known Fusarium strains, F. oxysporum strain EId (CNCM-I-1622 (Foxy and F. arthrosporioides strain E4a (CNCM-I-1621 (Farth were equally effective in controlling broomrape parasitizing tomato plants grown in pots, where the dead spikes of broomrape increased by 50.0 and 51.6%, respectively.

  19. 75 FR 28233 - Availability of an Environmental Assessment for a Biological Control Agent for Asian Citrus Psyllid

    Science.gov (United States)

    2010-05-20

    ...] Availability of an Environmental Assessment for a Biological Control Agent for Asian Citrus Psyllid AGENCY... radiata, into the continental United States for use as a biological control agent to reduce the severity... of an alternative biological control agent, an encyrtid wasp, (Diaphorencyrtus aligarhensis). However...

  20. 77 FR 46373 - Field Release of Aphelinus glycinis for the Biological Control of the Soybean Aphid in the...

    Science.gov (United States)

    2012-08-03

    ... Inspection Service [Docket No APHIS-2012-0061] Field Release of Aphelinus glycinis for the Biological Control... for the biological control of the soybean aphid, Aphis glycines, in the continental United States. We... glycinis for the Biological Control of the Soybean Aphid in the Continental United States'' (March 2012...

  1. New experimental approaches to the biology of flight control systems.

    Science.gov (United States)

    Taylor, Graham K; Bacic, Marko; Bomphrey, Richard J; Carruthers, Anna C; Gillies, James; Walker, Simon M; Thomas, Adrian L R

    2008-01-01

    Here we consider how new experimental approaches in biomechanics can be used to attain a systems-level understanding of the dynamics of animal flight control. Our aim in this paper is not to provide detailed results and analysis, but rather to tackle several conceptual and methodological issues that have stood in the way of experimentalists in achieving this goal, and to offer tools for overcoming these. We begin by discussing the interplay between analytical and empirical methods, emphasizing that the structure of the models we use to analyse flight control dictates the empirical measurements we must make in order to parameterize them. We then provide a conceptual overview of tethered-flight paradigms, comparing classical ;open-loop' and ;closed-loop' setups, and describe a flight simulator that we have recently developed for making flight dynamics measurements on tethered insects. Next, we provide a conceptual overview of free-flight paradigms, focusing on the need to use system identification techniques in order to analyse the data they provide, and describe two new techniques that we have developed for making flight dynamics measurements on freely flying birds. First, we describe a technique for obtaining inertial measurements of the orientation, angular velocity and acceleration of a steppe eagle Aquila nipalensis in wide-ranging free flight, together with synchronized measurements of wing and tail kinematics using onboard instrumentation and video cameras. Second, we describe a photogrammetric method to measure the 3D wing kinematics of the eagle during take-off and landing. In each case, we provide demonstration data to illustrate the kinds of information available from each method. We conclude by discussing the prospects for systems-level analyses of flight control using these techniques and others like them.

  2. Control of biological hazards in cold smoked salmon production

    DEFF Research Database (Denmark)

    Huss, Hans Henrik; Embarek, Peter Karim Ben; Jeppesen, V.F.

    1995-01-01

    An outline of the common processing technology for cold smoked salmon in Denmark is presented. The safety hazards related to pathogenic bacteria, parasites and biogenic amines are discussed with special emphasis on hazards related to Clostridium botulinum and Listeria monocytogenes. Critical...... control points are identified for all hazards except growth of L. monocytogenes. For this reason a limitation of shelf life to three weeks at +5 degrees C far cold smoked vacuum-packed salmon having greater than or equal to 3% water phase salt is recommended...

  3. Controlling of bacterial flora contaminating animal diet and its components by gamma irradiation

    International Nuclear Information System (INIS)

    El-Fouly, M.Z.; El-Zawahry, Y.A.; Helal, G.A.; El-Hady, A.F.

    1991-01-01

    The total bacterial counts in complete diets were found to range between 10 3 -10 5 cells/g, which they ranged between 10 2 and 10 6 in the main components. One hundred and sixteen bacterial colonies were isolated from the animal diet samples and found to be gram positive belonging to three genera: Staphylococcus, Streptococcus and Bacillus. The most radioresistant bacteria isolated at 7.5 KGy were identified as B. megaterium, B. licheniformis, B. pumilus, B.circulans and B.laterosporus. The D 1 0 values for the bacteria contaminated the diet samples ranged between 928 Gy and 2199 Gy. Meanwhile, the D 1 0 values of staph.aureus and Strapt.faecalis artificially contaminated the diet were 400 Gy and 1136 Gy, respectively. It could be recommended from obtained results that dose level of 10 KGy is quite sufficient to eliminate all pathogens from animal diets or their components. In addition, it decreases the microbial count to minimum counts and hence increases the diet shelf life.1 fig.,4 tab

  4. New Weapons to Fight Old Enemies: Novel Strategies for the (Bio)control of Bacterial Biofilms in the Food Industry.

    Science.gov (United States)

    Coughlan, Laura M; Cotter, Paul D; Hill, Colin; Alvarez-Ordóñez, Avelino

    2016-01-01

    Biofilms are microbial communities characterized by their adhesion to solid surfaces and the production of a matrix of exopolymeric substances, consisting of polysaccharides, proteins, DNA and lipids, which surround the microorganisms lending structural integrity and a unique biochemical profile to the biofilm. Biofilm formation enhances the ability of the producer/s to persist in a given environment. Pathogenic and spoilage bacterial species capable of forming biofilms are a significant problem for the healthcare and food industries, as their biofilm-forming ability protects them from common cleaning processes and allows them to remain in the environment post-sanitation. In the food industry, persistent bacteria colonize the inside of mixing tanks, vats and tubing, compromising food safety and quality. Strategies to overcome bacterial persistence through inhibition of biofilm formation or removal of mature biofilms are therefore necessary. Current biofilm control strategies employed in the food industry (cleaning and disinfection, material selection and surface preconditioning, plasma treatment, ultrasonication, etc.), although effective to a certain point, fall short of biofilm control. Efforts have been explored, mainly with a view to their application in pharmaceutical and healthcare settings, which focus on targeting molecular determinants regulating biofilm formation. Their application to the food industry would greatly aid efforts to eradicate undesirable bacteria from food processing environments and, ultimately, from food products. These approaches, in contrast to bactericidal approaches, exert less selective pressure which in turn would reduce the likelihood of resistance development. A particularly interesting strategy targets quorum sensing systems, which regulate gene expression in response to fluctuations in cell-population density governing essential cellular processes including biofilm formation. This review article discusses the problems associated

  5. Control of BTEX migration using a biologically enhanced permeable barrier

    International Nuclear Information System (INIS)

    Borden, R.C.; Goin, R.T.; Kao, C.M.

    1997-01-01

    A permeable barrier system, consisting of a line of closely spaced wells, was installed perpendicular to ground water flow to control the migration of a dissolved hydrocarbon plume. The wells were charged with concrete briquets that release oxygen and nitrate at a controlled rate, enhancing aerobic biodegradation in the downgradient aquifer. Laboratory batch reactor experiments were conducted to identify concrete mixtures that slowly released oxygen over an extended time period. A full-scale permeable barrier system using ORC was constructed at a gasoline-spill site. During the first 242 days of operation, total BTEX decreased from 17 to 3.4 mg/L and dissolved oxygen increased from 0.4 to 1.8 mg/L during transport through the barrier. Over time, BTEX treatment efficiencies declined, indicating the barrier system had become less effective in releasing oxygen and nutrients to the highly contaminated portion of the aquifer. Point dilution tests and sediment analyses performed at the conclusion of the project indicated that the aquifer in the vicinity of the remediation wells had been clogged by precipitation with iron minerals

  6. Can Flowering Greencover Crops Promote Biological Control in German Vineyards?

    Directory of Open Access Journals (Sweden)

    Christoph Hoffmann

    2017-11-01

    Full Text Available Greencover crops are widely recommended to provide predators and parasitoids with floral resources for improved pest control. We studied parasitism and predation of European grapevine moth (Lobesia botrana eggs and pupae as well as predatory mite abundances in an experimental vineyard with either one or two sowings of greencover crops compared to spontaneous vegetation. The co-occurrence between greencover flowering time and parasitoid activity differed greatly between the two study years. Parasitism was much higher when flowering and parasitoid activity coincided. While egg predation was enhanced by greencover crops, there were no significant benefits of greencover crops on parasitism of L. botrana eggs or pupae. Predatory mites did not show an as strong increase on grapevines in greencover crop plots as egg predation. Overall, our study demonstrates only limited pest control benefits of greencover crops. Given the strong within- and between year variation in natural enemy activity, studies across multiple years will be necessary to adequately describe the role of greencover crops for pest management and to identify the main predators of L. botrana eggs.

  7. The role and control of sludge age in biological nutrient removal activated sludge systems.

    Science.gov (United States)

    Ekama, G A

    2010-01-01

    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor concentration does not control sludge age, only the mass of sludge in the system. When nitrification is a requirement, sludge age control becomes a requirement and the secondary settling tanks can no longer serve the dual purpose of clarifier and waste activated sludge thickeners. The easiest and most practical way to control sludge age is with hydraulic control by wasting a defined proportion of the reactor volume daily. In AS plants with reactor concentration control, nitrification fails first. With hydraulic control of sludge age, nitrification will not fail, rather the plant fails by shedding solids over the secondary settling tank effluent weirs.

  8. Clay-to-carbon ratio controls the effect of herbicide application on soil bacterial richness and diversity in a loamy field

    DEFF Research Database (Denmark)

    Herath, H M Lasantha I; Møldrup, Per; de Jonge, Lis Wollesen

    2017-01-01

    Soil texture and soil organic carbon (OC) influence the bacterial microenvironment and also control herbicide sorption. A field-scale exploratory study was conducted to investigate the potential interaction between soil texture parameters, herbicides, and soil bacterial richness and diversity......-based coverage (ACE), Shannon diversity index, and phylogenetic diversity. In general, bacterial richness and diversity increased after bentazon application and decreased after glyphosate application. There was no significant effect for field locations with Dexter n (the ratio between clay and OC) values below 4...

  9. Investigating Biological Control Agents for Controlling Invasive Populations of the Mealybug Pseudococcus comstocki in France.

    Directory of Open Access Journals (Sweden)

    Thibaut Malausa

    Full Text Available Pseudococcus comstocki (Hemiptera: Pseudococcidae is a mealybug species native to Eastern Asia and present as an invasive pest in northern Italy and southern France since the start of the century. It infests apple and pear trees, grapevines and some ornamental trees. Biocontrol programmes against this pest proved successful in central Asia and North America in the second half of the 20th century. In this study, we investigated possible biocontrol agents against P. comstocki, with the aim of developing a biocontrol programme in France. We carried out systematic DNA-barcoding at each step in the search for a specialist parasitoid. First we characterised the French target populations of P. comstocki. We then identified the parasitoids attacking P. comstocki in France. Finally, we searched for foreign mealybug populations identified a priori as P. comstocki and surveyed their hymenopteran parasitoids. Three mealybug species (P. comstocki, P. viburni and P. cryptus were identified during the survey, together with at least 16 different parasitoid taxa. We selected candidate biological control agent populations for use against P. comstocki in France, from the species Allotropa burrelli (Hymenoptera: Platygastridae and Acerophagus malinus (Hymenoptera: Encyrtidae. The coupling of molecular and morphological characterisation for both pests and natural enemies facilitated the programme development and the rejection of unsuitable or generalist parasitoids.

  10. Bacterial Cell Enlargement Requires Control of Cell Wall Stiffness Mediated by Peptidoglycan Hydrolases.

    Science.gov (United States)

    Wheeler, Richard; Turner, Robert D; Bailey, Richard G; Salamaga, Bartłomiej; Mesnage, Stéphane; Mohamad, Sharifah A S; Hayhurst, Emma J; Horsburgh, Malcolm; Hobbs, Jamie K; Foster, Simon J

    2015-07-28

    Most bacterial cells are enclosed in a single macromolecule of the cell wall polymer, peptidoglycan, which is required for shape determination and maintenance of viability, while peptidoglycan biosynthesis is an important antibiotic target. It is hypothesized that cellular enlargement requires regional expansion of the cell wall through coordinated insertion and hydrolysis of peptidoglycan. Here, a group of (apparent glucosaminidase) peptidoglycan hydrolases are identified that are together required for cell enlargement and correct cellular morphology of Staphylococcus aureus, demonstrating the overall importance of this enzyme activity. These are Atl, SagA, ScaH, and SagB. The major advance here is the explanation of the observed morphological defects in terms of the mechanical and biochemical properties of peptidoglycan. It was shown that cells lacking groups of these hydrolases have increased surface stiffness and, in the absence of SagB, substantially increased glycan chain length. This indicates that, beyond their established roles (for example in cell separation), some hydrolases enable cellular enlargement by making peptidoglycan easier to stretch, providing the first direct evidence demonstrating that cellular enlargement occurs via modulation of the mechanical properties of peptidoglycan. Understanding bacterial growth and division is a fundamental problem, and knowledge in this area underlies the treatment of many infectious diseases. Almost all bacteria are surrounded by a macromolecule of peptidoglycan that encloses the cell and maintains shape, and bacterial cells must increase the size of this molecule in order to enlarge themselves. This requires not only the insertion of new peptidoglycan monomers, a process targeted by antibiotics, including penicillin, but also breakage of existing bonds, a potentially hazardous activity for the cell. Using Staphylococcus aureus, we have identified a set of enzymes that are critical for cellular enlargement. We

  11. Biological activities of Allium sativum and Zingiber officinale extracts on clinically important bacterial pathogens, their phytochemical and FT-IR spectroscopic analysis.

    Science.gov (United States)

    Awan, Uzma Azeem; Ali, Shaukat; Shahnawaz, Amna Mir; Shafique, Irsa; Zafar, Atiya; Khan, Muhammad Abdul Rauf; Ghous, Tahseen; Saleem, Azhar; Andleeb, Saiqa

    2017-05-01

    The spread of bacterial infectious diseases is a major public threat. Herbs and spices have offered an excellent, important and useful source of antimicrobial agents against many pathological infections. In the current study, the antimicrobial potency of fresh, naturally and commercial dried Allium sativum and Zingiber officinale extracts had been investigated against seven local clinical bacterial isolates such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus pyogenes, Staphylococcus epidermidis, and Serratia marcesnces by the agar disc diffusion method. All tested pathogens except P. aeruginosa and E. coli were most susceptible to ethanolic and methanolic extracts of A. sativum. Similarly, chloroform and diethyl ether extracts of Z. officinale showed a greater zone of inhibition of tested pathogens except for P. aeruginosa and E. coli. We found that all extracts of A. sativum and Z. officinale have a strong antibacterial effect compared to recommended standard antibiotics through activity index. All results were evaluated statistically and a significant difference was recorded at Psativum and Z. officinale proposed the presence of various phytochemicals such as tannins, phenols, alkaloids, steroids and saponins. Retention factor of diverse phytochemicals provides a valuable clue regarding their polarity and the selection of solvents for separation of phytochemicals. Significant inhibition of S. aureus was also observed through TLC-Bioautography. FT-IR Spectrometry was also performed to characterize both natural and commercial extracts of A. sativum and Z. officinale to evaluate bioactive compounds. These findings provide new insights to use A. sativum and Z. officinale as potential plant sources for controlling pathogenic bacteria and potentially considered as cost-effective in the management of diseases and to the threat of drug resistance phenomenon.

  12. Zika virus: History, emergence, biology, and prospects for control.

    Science.gov (United States)

    Weaver, Scott C; Costa, Federico; Garcia-Blanco, Mariano A; Ko, Albert I; Ribeiro, Guilherme S; Saade, George; Shi, Pei-Yong; Vasilakis, Nikos

    2016-06-01

    Zika virus (ZIKV), a previously obscure flavivirus closely related to dengue, West Nile, Japanese encephalitis and yellow fever viruses, has emerged explosively since 2007 to cause a series of epidemics in Micronesia, the South Pacific, and most recently the Americas. After its putative evolution in sub-Saharan Africa, ZIKV spread in the distant past to Asia and has probably emerged on multiple occasions into urban transmission cycles involving Aedes (Stegomyia) spp. mosquitoes and human amplification hosts, accompanied by a relatively mild dengue-like illness. The unprecedented numbers of people infected during recent outbreaks in the South Pacific and the Americas may have resulted in enough ZIKV infections to notice relatively rare congenital microcephaly and Guillain-Barré syndromes. Another hypothesis is that phenotypic changes in Asian lineage ZIKV strains led to these disease outcomes. Here, we review potential strategies to control the ongoing outbreak through vector-centric approaches as well as the prospects for the development of vaccines and therapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Biological control of dodder (Cuscuta campestris L. by fungi pathogens

    Directory of Open Access Journals (Sweden)

    F. Fallahpour

    2016-04-01

    Full Text Available Parasite weeds are the most important yield reducing factors, and among them dodder (Cuscuta campestris L. is an obligate parasite of many plant families. In order to find a suitable biocontrol agent for dodder a study was conducted based on a randomized complete design with four replications at research greenhouse of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran during 2007-2009. Diseased dodders sampled from sugarbeet farms of Chenaran, Iran. After culturing and isolating exiting fungi from infected tissues of dodder, Fusarium sp., Alternaria sp. and Colletotrichum sp. were recognized. Inoculation of isolates was carried out with concenteration of 1×108 spores per ml sterile water at different growth stages of dodder in labratoary and greenhouse. Among different fungi, isolate of 323 of F. oxysporum showed an effective control on germination of dodder seeds and the highest level of plant pathogencity was before the contact of dodder with host and infection in older plants decreased. Infection of this isolate with crops such as sugarbeet (Beta vulgaris L., alfalfa (Medigago sativa L., basil (Ocimum basilicum L., wheat (Triticum aestivum L. and barley (Hordeum vulgare L. showed no symptoms.

  14. Biology and control of swamp dodder (Cuscuta gronovii)

    International Nuclear Information System (INIS)

    Bewick, T.A.

    1987-01-01

    A simple model predicting swamp dodder (Cuscuta gronovii Willd.) emergence was developed. The model states that 0.1% of the cranberry seedlings will emerge after 150 to 170 GDD have accumulated after the winter ice has melted on the cranberry beds, using 0 C as the low temperature threshold. Experiments in cranberry showed that pronamide [3,5-dichloro-(N-1,1-dimethyl-2-propynyl)benzamide] was effective in controlling swamp dodder when applied preemergence. Rates below 2.4 kg ai/ha appeared to be safe for cranberry plants and fruit. Experiments with 14 C glyphosate showed that the herbicide moved out of carrot leaves to the physiological sinks in the plant. In carrots parasitized by swamp dodder the dodder acted as one of the strongest sinks for photosynthates from the host. In cranberry glyphosate moved out of the leaves, but most remained in the stem to which the treated leaves were attached. The only physiological sinks that accumulated significant amounts of label were the stem apices. The concentration of the herbicide in this sink decreased with time. Swamp dodder stems were able to absorb glyphosate directly from solution

  15. Assessing the status of biological control as a management tool for suppression of invasive alien plants in South Africa

    OpenAIRE

    Zachariades, Costas; Paterson, Iain D.; Strathie, Lorraine W.; Hill, Martin P.; van Wilgen, Brian W.

    2017-01-01

    Background: Biological control of invasive alien plants (IAPs) using introduced natural enemies contributes significantly to sustained, cost-effective management of natural resources in South Africa. The status of, and prospects for, biological control is therefore integral to National Status Reports (NSRs) on Biological Invasions, the first of which is due in 2017. Objectives: Our aim was to evaluate the status of, and prospects for, biological control of IAPs in South Africa. We discuss...

  16. Vaccination for the control of childhood bacterial pneumonia - Haemophilus influenzae type b and pneumococcal vaccines

    Directory of Open Access Journals (Sweden)

    Diana C Otczyk

    2013-01-01

    Full Text Available Pneumonia in childhood is endemic in large parts of the world and in particular, in developing countries, as well as in many indigenous communities within developed nations. Haemophilus influenzae type b and Streptococcus pneumoniae conjugate vaccines are currently available against the leading bacterial causes of pneumonia.  The use of the vaccines in both industrialised and developing countries have shown a dramatic reduction in the burden of pneumonia and invasive disease in children.  However, the greatest threat facing pneumococcal conjugate vaccine effectiveness is serotype replacement.  The current vaccines provide serotype-specific, antibody–mediated protection against only a few of the 90+ capsule serotypes.  Therefore, there has been a focus in recent years to rapidly advance technologies that will result in broader disease coverage and more affordable vaccines that can be used in developing countries.  The next generation of pneumococcal vaccines have advanced to clinical trials.

  17. Biologically inspired control of humanoid robot arms robust and adaptive approaches

    CERN Document Server

    Spiers, Adam; Herrmann, Guido

    2016-01-01

    This book investigates a biologically inspired method of robot arm control, developed with the objective of synthesising human-like motion dynamically, using nonlinear, robust and adaptive control techniques in practical robot systems. The control method caters to a rising interest in humanoid robots and the need for appropriate control schemes to match these systems. Unlike the classic kinematic schemes used in industrial manipulators, the dynamic approaches proposed here promote human-like motion with better exploitation of the robot’s physical structure. This also benefits human-robot interaction. The control schemes proposed in this book are inspired by a wealth of human-motion literature that indicates the drivers of motion to be dynamic, model-based and optimal. Such considerations lend themselves nicely to achievement via nonlinear control techniques without the necessity for extensive and complex biological models. The operational-space method of robot control forms the basis of many of the techniqu...

  18. Quantifying conservation biological control for management of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton

    Science.gov (United States)

    Conservation biological control can be an effective tactic for minimizing insect-induced damage to agricultural production. The most effective manner of applying CBC is through an Integrated Pest Management (IPM) strategy, combining many tactics including cultural controls, pest sampling, the use of...

  19. Hybridization between a native and introduced predator of Adelgidae: An unintended result of classical biological control

    Science.gov (United States)

    N.P. Havill; Gina Davis; David Mausel; Joanne Klein; Richard McDonald; Cera Jones; Melissa Fischer; Scott Salom; Adelgisa. Caccone

    2012-01-01

    Hybridization between introduced biological control agents and native species has the potential to impact native biodiversity and pest control efforts. This study reports progress towards predicting the outcome of hybridization between two beetle species, the introduced Laricobius nigrinus Fender and the native L. rubidus LeConte...

  20. Compatible biological and chemical control systems for Rhizoctonia solani in potato

    NARCIS (Netherlands)

    Boogert, van den P.H.J.F.; Luttikholt, A.J.G.

    2004-01-01

    A series of chemical and biological control agents were tested for compatibility with the Rhizoctonia-specific biocontrol fungus Verticillium biguttatum aimed at designing novel control strategies for black scurf (Rhizoctonia solani) and other tuber diseases in potato. The efficacy of chemicals,

  1. Candidate predators for biological control of the poultry red mite Dermanyssus gallinae

    NARCIS (Netherlands)

    Lesna, I.; Wolfs, P.; Faraji, F.; Roy, L.; Komdeur, J.; Sabelis, M.W.

    2009-01-01

    The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify

  2. Candidate predators for biological control of the poultry red mite Dermanyssus gallinae

    NARCIS (Netherlands)

    Lesna, Izabela; Wolfs, Peter; Faraji, Farid; Roy, Lise; Komdeur, Jan; Sabelis, Maurice W.

    The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify

  3. Lysis-deficient phages as novel therapeutic agents for controlling bacterial infection

    Directory of Open Access Journals (Sweden)

    Kempashanaiah Nanjundappa

    2011-08-01

    Full Text Available Abstract Background Interest in phage therapy has grown over the past decade due to the rapid emergence of antibiotic resistance in bacterial pathogens. However, the use of bacteriophages for therapeutic purposes has raised concerns over the potential for immune response, rapid toxin release by the lytic action of phages, and difficulty in dose determination in clinical situations. A phage that kills the target cell but is incapable of host cell lysis would alleviate these concerns without compromising efficacy. Results We developed a recombinant lysis-deficient Staphylococcus aureus phage P954, in which the endolysin gene was rendered nonfunctional by insertional inactivation. P954, a temperate phage, was lysogenized in S. aureus strain RN4220. The native endolysin gene on the prophage was replaced with an endolysin gene disrupted by the chloramphenicol acetyl transferase (cat gene through homologous recombination using a plasmid construct. Lysogens carrying the recombinant phage were detected by growth in presence of chloramphenicol. Induction of the recombinant prophage did not result in host cell lysis, and the phage progeny were released by cell lysis with glass beads. The recombinant phage retained the endolysin-deficient genotype and formed plaques only when endolysin was supplemented. The host range of the recombinant phage was the same as that of the parent phage. To test the in vivo efficacy of the recombinant endolysin-deficient phage, immunocompromised mice were challenged with pathogenic S. aureus at a dose that results in 80% mortality (LD80. Treatment with the endolysin-deficient phage rescued mice from the fatal S. aureus infection. Conclusions A recombinant endolysin-deficient staphylococcal phage has been developed that is lethal to methicillin-resistant S. aureus without causing bacterial cell lysis. The phage was able to multiply in lytic mode utilizing a heterologous endolysin expressed from a plasmid in the propagation host

  4. Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence.

    Directory of Open Access Journals (Sweden)

    Shi-qi An

    2014-10-01

    Full Text Available Bis-(3',5' cyclic di-guanylate (cyclic di-GMP is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc. This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (K(d∼2 µM. Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence.

  5. Control biológico del entrenamiento de resistencia. Biological control of endurance training.

    Directory of Open Access Journals (Sweden)

    González Gross, Marcela

    2006-01-01

    Full Text Available ResumenLa alta exigencia en los deportistas de elite hace cada vez más necesario controlar el proceso de adaptación al entrenamiento. El objetivo de esta revisión es analizar la información biológica de un análisis de sangre, al objeto de obtener información de la carga de entrenamiento en atletas de resistencia. La mayor parte de los parámetros sanguíneos han sido empleados, más que para determinar el proceso del entrenamiento, precisamente, para lo opuesto: el sobreentrenamiento. La concentración en plasma de sustratos metabólicos (glucosa y ácidos grasos no son parámetros que pueda utilizarse para controlar el entrenamiento, debido a las bajas especificidad y sensibilidad. No obstante, la concentración de determinados enzimas que intervienen en la utilización de los sustratos puede ser importante. Valores de creatín kinasa superiores a 200 U/l en una persona sana sugiere claramente que la carga de entrenamiento total de una determinada sesión ha sido elevada. La concentración en plasma de algún producto de degradación del catabolismo también puede señalar la adaptación del organismo al entrenamiento. La concentración de ácido láctico en plasma es la herramienta más común en la valoración de la carga de entrenamiento. La concentración de urea es un buen marcador biológico de la carga de entrenamiento. Valores superiores a 8 mmol/l en varones y de 6,5 mmol/l en mujeres, indican que el entrenamiento ha sido muy intenso. La determinación de otros productos (amonio o sustratos (glutamina se han utilizado para detectar el sobreentrenamiento.AbstractThe high exigency in the elite sportsmen does more necessary to control the process of training adaptation. The purpose of this review is to analyze the biological information of a blood analysis to obtain data of load training in endurance athletes. Most blood parameters has been used to evaluate the overtraining state instead of determining the training process. The

  6. The Main Biological Hazards in Animal Biosafety Level 2 Facilities and Strategies for Control.

    Science.gov (United States)

    Li, Xiao Yan; Xue, Kang Ning; Jiang, Jin Sheng; Lu, Xuan Cheng

    2016-04-01

    Concern about the biological hazards involved in microbiological research, especially research involving laboratory animals, has increased in recent years. Working in an animal biosafety level 2 facility (ABSL-2), commonly used for research on infectious diseases, poses various biological hazards. Here, the regulations and standards related to laboratory biosafety in China are introduced, the potential biological hazards present in ABSL-2 facilities are analyzed, and a series of strategies to control the hazards are presented. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  7. labelling and quality control of some 99m Tc-radiopharmaceuticals of expected biological activity

    International Nuclear Information System (INIS)

    Abdallah, A.B.I.

    2009-01-01

    this thesis addresses the labelling and quality control of some 99m Tc-radiopharmaceuticals which could be used for infection imaging. this study focuses on the labelling of sarafloxation, gatifloxation and cefepine with technetium-99m and biological evaluation of these labeled complexes and biodistribution in both normal and inflamed mice. the thesis is organized into two chapters: chapter I :labelling of some antibiotics chapter II :biological evaluation.

  8. Bacterial antagonists of fungal pathogens also control root-knot nematodes by induced systemic resistance of tomato plants.

    Directory of Open Access Journals (Sweden)

    Mohamed Adam

    Full Text Available The potential of bacterial antagonists of fungal pathogens to control the root-knot nematode Meloidogyne incognita was investigated under greenhouse conditions. Treatment of tomato seeds with several strains significantly reduced the numbers of galls and egg masses compared with the untreated control. Best performed Bacillus subtilis isolates Sb4-23, Mc5-Re2, and Mc2-Re2, which were further studied for their mode of action with regard to direct effects by bacterial metabolites or repellents, and plant mediated effects. Drenching of soil with culture supernatants significantly reduced the number of egg masses produced by M. incognita on tomato by up to 62% compared to the control without culture supernatant. Repellence of juveniles by the antagonists was shown in a linked twin-pot set-up, where a majority of juveniles penetrated roots on the side without inoculated antagonists. All tested biocontrol strains induced systemic resistance against M. incognita in tomato, as revealed in a split-root system where the bacteria and the nematodes were inoculated at spatially separated roots of the same plant. This reduced the production of egg masses by up to 51%, while inoculation of bacteria and nematodes in the same pot had only a minor additive effect on suppression of M. incognita compared to induced systemic resistance alone. Therefore, the plant mediated effect was the major reason for antagonism rather than direct mechanisms. In conclusion, the bacteria known for their antagonistic potential against fungal pathogens also suppressed M. incognita. Such "multi-purpose" bacteria might provide new options for control strategies, especially with respect to nematode-fungus disease complexes that cause synergistic yield losses.

  9. Bacterial antagonists of fungal pathogens also control root-knot nematodes by induced systemic resistance of tomato plants.

    Science.gov (United States)

    Adam, Mohamed; Heuer, Holger; Hallmann, Johannes

    2014-01-01

    The potential of bacterial antagonists of fungal pathogens to control the root-knot nematode Meloidogyne incognita was investigated under greenhouse conditions. Treatment of tomato seeds with several strains significantly reduced the numbers of galls and egg masses compared with the untreated control. Best performed Bacillus subtilis isolates Sb4-23, Mc5-Re2, and Mc2-Re2, which were further studied for their mode of action with regard to direct effects by bacterial metabolites or repellents, and plant mediated effects. Drenching of soil with culture supernatants significantly reduced the number of egg masses produced by M. incognita on tomato by up to 62% compared to the control without culture supernatant. Repellence of juveniles by the antagonists was shown in a linked twin-pot set-up, where a majority of juveniles penetrated roots on the side without inoculated antagonists. All tested biocontrol strains induced systemic resistance against M. incognita in tomato, as revealed in a split-root system where the bacteria and the nematodes were inoculated at spatially separated roots of the same plant. This reduced the production of egg masses by up to 51%, while inoculation of bacteria and nematodes in the same pot had only a minor additive effect on suppression of M. incognita compared to induced systemic resistance alone. Therefore, the plant mediated effect was the major reason for antagonism rather than direct mechanisms. In conclusion, the bacteria known for their antagonistic potential against fungal pathogens also suppressed M. incognita. Such "multi-purpose" bacteria might provide new options for control strategies, especially with respect to nematode-fungus disease complexes that cause synergistic yield losses.

  10. Impact of soil salinity on the plant-growth – promoting and biological control abilities of root associated bacteria

    Directory of Open Access Journals (Sweden)

    Dilfuza Egamberdieva

    2017-11-01

    Full Text Available The effectiveness of plant growth – promoting bacteria is variable under different biotic and abiotic conditions. Abiotic factors may negatively affect the beneficial properties and efficiency of the introduced PGPR inoculants. The aim of this study was to evaluate the effect of plant growth – promoting rhizobacteria on plant growth and on the control of foot and root rot of tomatoes caused by Fusarium solani under different soil salinity conditions. Among the five tested strains, only Pseudomonas chlororaphis TSAU13, and Pseudomonas extremorientalis TSAU20 were able to stimulate plant growth and act as biological controls of foot and root rot disease of tomato. The soil salinity did not negatively affect the beneficial impacts of these strains, as they were able to colonize and survive on the roots of tomato plants under both saline and non-saline soil conditions. The improved plant height and fruit yield of tomato was also observed for plants inoculated with P. extremorientalis TSAU20. Our results indicated that, saline condition is not crucial factor in obtaining good performance with respect to the plant growth stimulating and biocontrol abilities of PGPR strains. The bacterial inoculant also enhanced antioxidant enzymes activities thereby preventing ROS induced oxidative damage in plants, and the proline concentrations in plant tissue that play an important role in plant stress tolerance.

  11. Connecting the dots between bacterial biofilms and ice cream

    Science.gov (United States)

    Stanley-Wall, Nicola R.; MacPhee, Cait E.

    2015-12-01

    Emerging research is revealing a diverse array of interfacially-active proteins that are involved in varied biological process from foaming horse sweat to bacterial raincoat formation. We describe an interdisciplinary approach to study the molecular and biophysical mechanisms controlling the activity of an unusual bacterial protein called BslA. This protein is needed for biofilm formation and forms a protective layer or raincoat over the bacterial community, but also has a multitude of potential applications in multiphase formulations. Here we document our journey from fundamental research to an examination of the applications for this surface-active protein in ice cream.

  12. Influence of CeO2 NPs on biological phosphorus removal and bacterial community shifts in a sequencing batch biofilm reactor with the differential effects of molecular oxygen

    International Nuclear Information System (INIS)

    Xu, Yi; Wang, Chao; Hou, Jun; Wang, Peifang; You, Guoxiang; Miao, Lingzhan; Lv, Bowen; Yang, Yangyang

    2016-01-01

    The effects of CeO 2 nanoparticles (CeO 2 NPs) on a sequencing batch biofilm reactor (SBBR) with established biological phosphorus (P) removal were investigated from the processes of anaerobic P release and aerobic P uptake. At low concentration (0.1 mg/L), no significant impact was observed on total phosphorus (TP) removal after operating for 8 h. However, at a concentration of 20 mg/L, TP removal efficiency decreased from 83.68% to 55.88% and 16.76% when the CeO 2 NPs were added at the beginning of the anaerobic and aerobic periods, respectively. Further studies illustrated that the inhibition of the specific P release rate was caused by the reversible states of Ce 3+ and Ce 4+ , which inhibited the activity of exopolyphosphatase (PPX) and transformation of poly-β-hydoxyalkanoates (PHA) and glycogen, as well as the uptake of volatile fatty acids (VFAs). The decrease in the specific P uptake rate was mainly attributed to the significantly suppressed energy generation and decreased abundance of Burkholderia caused by excess reactive oxygen species. The removal of chemical oxygen demand (COD) was not influenced by CeO 2 NPs under aerobic conditions, due to the increased abundance of Acetobacter and Acidocella after exposure. The inhibitory effects of CeO 2 NPs with molecular oxygen were reduced after anaerobic exposure due to the enhanced particle size and the presence of Ce 3+ . - Highlights: • CeO 2 NPs (20 mg/L) had a notable toxicity effect on P removal in SBBR system. • The deteriorated SPRR was caused by the inhibited key enzyme activity (PPX). • The decreased SPUR was caused by the bacterial community shifts. • Ce ions converting and excess ROS generation are related toxicity mechanisms.

  13. Biologically Inspired Modular Neural Control for a Leg-Wheel Hybrid Robot

    DEFF Research Database (Denmark)

    Manoonpong, Poramate; Wörgötter, Florentin; Laksanacharoen, Pudit

    2014-01-01

    In this article we present modular neural control for a leg-wheel hybrid robot consisting of three legs with omnidirectional wheels. This neural control has four main modules having their functional origin in biological neural systems. A minimal recurrent control (MRC) module is for sensory signal...... processing and state memorization. Its outputs drive two front wheels while the rear wheel is controlled through a velocity regulating network (VRN) module. In parallel, a neural oscillator network module serves as a central pattern generator (CPG) controls leg movements for sidestepping. Stepping directions...... or they can serve as useful modules for other module-based neural control applications....

  14. Modelling approach for biological control of insect pest by releasing infected pest

    International Nuclear Information System (INIS)

    Tan Yuanshun; Chen Lansun

    2009-01-01

    Models of biological control have a long history of theoretical development that have focused on the interactions between a predator and a prey. Here we have extended the classical epidemic model to include a continuous and impulsive pest control strategies by releasing the infected pests bred in laboratory. For the continuous model, the results imply that the susceptible pest goes to extinct if the threshold condition R 0 0 > 1, the positive equilibrium of continuous model is globally asymptotically stable. Similarly, the threshold condition which guarantees the global stability of the susceptible pest-eradication periodic solution is obtained for the model with impulsive control strategy. Consequently, based on the results obtained in this paper, the control strategies which maintain the pests below an acceptably low level are discussed by controlling the release rate and impulsive period. Finally, the biological implications of the results and the efficiency of two control strategies are also discussed

  15. Evaluation of moxifloxacin 0.5% in treatment of nonperforated bacterial corneal ulcers: a randomized controlled trial.

    Science.gov (United States)

    Sharma, Namrata; Goel, Manik; Bansal, Shubha; Agarwal, Prakashchand; Titiyal, Jeewan S; Upadhyaya, Ashish D; Vajpayee, Rasik B

    2013-06-01

    To compare the equivalence of moxifloxacin 0.5% with a combination of fortified cefazolin sodium 5% and tobramycin sulfate 1.3% eye drops in the treatment of moderate bacterial corneal ulcers. Randomized, controlled, equivalence clinical trial. Microbiologically proven cases of bacterial corneal ulcers were enrolled in the study and were allocated randomly to 1 of the 2 treatment groups. Group A was given combination therapy (fortified cefazolin sodium 5% and tobramycin sulfate) and group B was given monotherapy (moxifloxacin 0.5%). The primary outcome variable for the study was percentage of the ulcers healed at 3 months. The secondary outcome variables were best-corrected visual acuity and resolution of infiltrates. Of a total of 224 patients with bacterial keratitis, 114 patients were randomized to group A, whereas 110 patients were randomized to group B. The mean ± standard deviation ulcer size in groups A and B were 4.2 ± 2 and 4.41 ± 1.5 mm, respectively. The prevalence of coagulase-negative Staphylococcus (40.9% in group A and 48.2% in group B) was similar in both the study groups. A complete resolution of keratitis and healing of ulcers occurred in 90 patients (81.8%) in group A and 88 patients (81.4%) in group B at 3 months. The observed percentage of healing at 3 months was less than the equivalence margin of 20%. Worsening of ulcer was seen in 18.2% cases in group A and in 18.5% cases in group B. Mean time to epithelialization was similar, and there was no significant difference in the 2 groups (P = 0.065). No serious events attributable to therapy were reported. Corneal healing using 0.5% moxifloxacin monotherapy is equivalent to that of combination therapy using fortified cefazolin and tobramycin in the treatment of moderate bacterial corneal ulcers. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  16. Genetic effects of ELISA-based segregation for control of bacterial kidney disease in Chinook salmon (Oncorhynchus tshawytscha)

    Science.gov (United States)

    Hard, J.J.; Elliott, D.G.; Pascho, R.J.; Chase, D.M.; Park, L.K.; Winton, J.R.; Campton, D.E.

    2006-01-01

    We evaluated genetic variation in ability of Chinook salmon (Oncorhynchus tshawytscha) to resist two bacterial pathogens: Renibacterium salmoninarum, the agent of bacterial kidney disease (BKD), and Listonella anguillarum, an agent of vibriosis. After measuring R. salmoninarum antigen in 499 adults by enzyme-linked immunosorbent assay (ELISA), we mated each of 12 males with high or low antigen levels to two females with low to moderate levels and exposed subsets of their progeny to each pathogen separately. We found no correlation between R. salmoninarum antigen level in parents and survival of their progeny following pathogen exposure. We estimated high heritability for resistance to R. salmoninarum (survival h2 = 0.890 ?? 0.256 (mean ?? standard error)) independent of parental antigen level, but low heritability for resistance to L. anguillarum (h2 = 0.128 ?? 0.078). The genetic correlation between these survivals (rA = -0.204 ?? 0.309) was near zero. The genetic and phenotypic correlations between survival and antigen levels among surviving progeny exposed to R. salmoninarum were both negative (rA = -0.716 ?? 0.140; rP = -0.378 ?? 0.041), indicating that variation in antigen level is linked to survival. These results suggest that selective culling of female broodstock with high antigen titers, which is effective in controlling BKD in salmon hatcheries, will not affect resistance of their progeny. ?? 2006 NRC.

  17. Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

    Science.gov (United States)

    Mangalo, Muna; Meckenstock, Rainer U.; Stichler, Willibald; Einsiedl, Florian

    2007-09-01

    Bacterial sulfate reduction is one of the most important respiration processes in anoxic habitats and is often assessed by analyzing the results of stable isotope fractionation. However, stable isotope fractionation is supposed to be influenced by the reduction rate and other parameters, such as temperature. We studied here the mechanistic basics of observed differences in stable isotope fractionation during bacterial sulfate reduction. Batch experiments with four sulfate-reducing strains ( Desulfovibrio desulfuricans, Desulfobacca acetoxidans, Desulfonatronovibrio hydrogenovorans, and strain TRM1) were performed. These microorganisms metabolize different carbon sources (lactate, acetate, formate, and toluene) and showed broad variations in their sulfur isotope enrichment factors. We performed a series of experiments on isotope exchange of 18O between residual sulfate and ambient water. Batch experiments were conducted with 18O-enriched (δ 18O water = +700‰) and depleted water (δ 18O water = -40‰), respectively, and the stable 18O isotope shift in the residual sulfate was followed. For Desulfovibrio desulfuricans and Desulfonatronovibrio hydrogenovorans, which are both characterized by low sulfur isotope fractionation ( ɛS > -13.2‰), δ 18O values in the remaining sulfate increased by only 50‰ during growth when 18O-enriched water was used for the growth medium. In contrast, with Desulfobacca acetoxidans and strain TRM1 ( ɛS factor ( ɛS exchange with water during sulfate reduction. However, this neither takes place in the sulfate itself nor during formation of APS (adenosine-5'-phosphosulfate), but rather in intermediates of the sulfate reduction pathway. These may in turn be partially reoxidized to form sulfate. This reoxidation leads to an incorporation of oxygen from water into the "recycled" sulfate changing the overall 18O isotopic composition of the remaining sulfate fraction. Our study shows that such incorporation of 18O is correlated with the

  18. Hybridization of an invasive shrub affects tolerance and resistance to defoliation by a biological control agent

    OpenAIRE

    Williams, Wyatt I; Friedman, Jonathan M; Gaskin, John F; Norton, Andrew P

    2014-01-01

    Evolution has contributed to the successful invasion of exotic plant species in their introduced ranges, but how evolution affects particular control strategies is still under evaluation. For instance, classical biological control, a common strategy involving the utilization of highly specific natural enemies to control exotic pests, may be negatively affected by host hybridization because of shifts in plant traits, such as root allocation or chemical constituents. We investigated introgressi...

  19. Natural biological control of pest mites in Brazilian sun coffee agroecosystems.

    Science.gov (United States)

    Teodoro, Adenir V; Sarmento, Renato A; Rêgo, Adriano S; da Graça S Maciel, Anilde

    2010-06-01

    Coffee is one of the leading commodities in tropical America. Although plantations are usually established under a canopy of trees in most producing countries in the region, Brazilian coffee is mostly produced under full sun conditions. Such simple, single-crop agroecosystems with intensive agrochemical inputs often suffer with pests like mites. Predatory mites of the family Phytoseiidae are the main natural enemies associated with pest mites in the field. However, these beneficial arthropods struggle to survive in intensive agroecosystems such as coffee monocultures due to unfavorable microclimatic conditions, widespread pesticide use, and lack of alternative food (pollen, nectar). Conservation biological control uses a range of management strategies to sustain and enhance populations of indigenous natural enemies such as predatory mites. We discuss here conservation biological control as a strategy to improve biological control of pest mites by native predatory mites in Brazilian coffee monocultures as well as some related patents.

  20. Using consumption rate to assess potential predators for biological control of white perch

    Directory of Open Access Journals (Sweden)

    Gosch N.J.C.

    2011-08-01

    Full Text Available Control of undesirable fishes is important in aquatic systems, and using predation as a tool for biological control is an attractive option to fishery biologists. However, determining the appropriate predators for biological control is critical for success. The objective of this study was to evaluate the utility of consumption rate as an index to determine the most effective predators for biological control of an invasive fish. Consumption rate values were calculated for nine potential predators that prey on white perch Morone americana in Branched Oak and Pawnee reservoirs, Nebraska. The consumption rate index provided a unique and insightful means of determining the potential effectiveness of each predator species in controlling white perch. Cumulative frequency distributions facilitated interpretation by providing a graphical presentation of consumption rates by all individuals within each predator species. Largemouth bass Micropterus salmoides, walleye Sander vitreus and sauger S. canadensis were the most efficient white perch predators in both reservoirs; however, previous attempts to increase biomass of these predators have failed suggesting that successful biological control is unlikely using existing predator species in these Nebraska reservoirs.

  1. Effect of biological activated carbon pre-treatment to control organic fouling in the microfiltration of biologically treated secondary effluent.

    Science.gov (United States)

    Pramanik, Biplob Kumar; Roddick, Felicity A; Fan, Linhua

    2014-10-15

    Biological activated carbon (BAC) filtration was investigated as a pre-treatment for reducing the organic fouling of a microfiltration membrane (0.1 μm polyvinylidene fluoride) in the treatment of a biologically treated secondary effluent (BTSE) from a municipal wastewater treatment plant. BAC treatment of the BTSE resulted in a marked improvement in permeate flux, which was attributed to the effective removal of organic foulants and particulates. Although the BAC removed significantly less dissolved organic carbon than the granular activated carbon (GAC) treatment which was used as a control for comparison, it led to a markedly greater flux. This was attributed to the effective removal of the very high molecular weight substances such as biopolymers by the BAC through biodegradation and adsorption of those molecules on the biofilm. Size exclusion chromatography showed the BAC treatment led to approximately 30% reduction in these substances, whereas the GAC did not greatly remove these molecules. The BAC treatment led to a greater reduction of loosely-attached and firmly-attached membrane surface foulant, and this was confirmed by attenuated total reflection-fourier transform infrared spectroscopy analysis. This study demonstrated the potential of BAC pre-treatment for reducing organic fouling and thus improving flux for the microfiltration of BTSE. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Intravaginal metronidazole gel versus metronidazole plus nystatin ovules for bacterial vaginosis: a randomized controlled trial.

    Science.gov (United States)

    Sanchez, Sixto; Garcia, Patricia J; Thomas, Katherine K; Catlin, Mary; Holmes, King K

    2004-12-01

    We compared metronidazole 0.75% gel (containing 37.5 mg metronidazole per dose) with ovules containing metronidazole 500 mg and nystatin 100,000 U, for intravaginal treatment of bacterial vaginosis (BV). In a single-blinded trial, symptomatic women with BV by both Amsel and Nugent criteria were randomly assigned to gel or ovules, once nightly for 5 nights, and asked to return 3 times after treatment. Analyses were intent-to-treat. Of 151 women with BV by both criteria at enrollment, 138 (91%) returned at least once. Product limit estimates for persistence or recurrence of BV at 14, 42, and 104 days were 20% (95% CI 10%-29%), 38% (95% CI 25%-48%), and 52% (95% CI 37%-63%) after gel treatment, and 4% (95% CI 0%-9%), 17% (95% CI 7%-26%), and 33% (95% CI 21%-46%) after ovule treatment ( P = .01). Among women without BV at first follow-up, subsequent intercourse without condoms independently predicted subsequent recurrence ( P Metronidazole/nystatin ovules were significantly more effective than metronidazole gel. Unprotected sex predicted recurrence after initial improvement.

  3. Evaluation of impedance on biological Tissues using automatic control measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Kil, Sang Hyeong; Shin, Dong Hoon; Lee, Seong Mo [Pusan National University, Yangsan (Korea, Republic of); Lee, Moo Seok; Kim, Sang Sik [Pusan National University, Busan (Korea, Republic of); Kim, Gun FDo; Lee, Jong Kyu [Pukyung National University, Busan (Korea, Republic of)

    2015-08-15

    Each biological tissue has endemic electrical characteristics owing to various differences such as those in cellular arrangement or organization form. The endemic electrical characteristics change when any biological change occurs. This work is a preliminary study surveying the changes in the electrical characteristics of biological tissue caused by radiation exposure. For protection against radiation hazards, therefore the electrical characteristics of living tissue were evaluated after development of the automatic control measurement system using LabVIEW. No alteration of biological tissues was observed before and after measurement of the electrical characteristics, and the biological tissues exhibited similar patterns. Through repeated measurements using the impedance/gain-phase analyzer, the coefficient of variation was determined as within 10%. The reproducibility impedance phase difference in electrical characteristics of the biological tissue did not change, and the tissue had resistance. The absolute value of impedance decreased constantly in proportion to the frequency. It has become possible to understand the electrical characteristics of biological tissues through the measurements made possible by the use of the developed.

  4. Evaluation of impedance on biological Tissues using automatic control measurement system

    International Nuclear Information System (INIS)

    Kil, Sang Hyeong; Shin, Dong Hoon; Lee, Seong Mo; Lee, Moo Seok; Kim, Sang Sik; Kim, Gun FDo; Lee, Jong Kyu

    2015-01-01

    Each biological tissue has endemic electrical characteristics owing to various differences such as those in cellular arrangement or organization form. The endemic electrical characteristics change when any biological change occurs. This work is a preliminary study surveying the changes in the electrical characteristics of biological tissue caused by radiation exposure. For protection against radiation hazards, therefore the electrical characteristics of living tissue were evaluated after development of the automatic control measurement system using LabVIEW. No alteration of biological tissues was observed before and after measurement of the electrical characteristics, and the biological tissues exhibited similar patterns. Through repeated measurements using the impedance/gain-phase analyzer, the coefficient of variation was determined as within 10%. The reproducibility impedance phase difference in electrical characteristics of the biological tissue did not change, and the tissue had resistance. The absolute value of impedance decreased constantly in proportion to the frequency. It has become possible to understand the electrical characteristics of biological tissues through the measurements made possible by the use of the developed.

  5. Bacterial Actins.

    Science.gov (United States)

    Izoré, Thierry; van den Ent, Fusinita

    2017-01-01

    A diverse set of protein polymers, structurally related to actin filaments contributes to the organization of bacterial cells as cytomotive or cytoskeletal filaments. This chapter describes actin homologs encoded by bacterial chromosomes. MamK filaments, unique to magnetotactic bacteria, help establishing magnetic biological compasses by interacting with magnetosomes. Magnetosomes are intracellular membrane invaginations containing biomineralized crystals of iron oxide that are positioned by MamK along the long-axis of the cell. FtsA is widespread across bacteria and it is one of the earliest components of the divisome to arrive at midcell, where it anchors the cell division machinery to the membrane. FtsA binds directly to FtsZ filaments and to the membrane through its C-terminus. FtsA shows altered domain architecture when compared to the canonical actin fold. FtsA's subdomain 1C replaces subdomain 1B of other members of the actin family and is located on the opposite side of the molecule. Nevertheless, when FtsA assembles into protofilaments, the protofilament structure is preserved, as subdomain 1C replaces subdomain IB of the following subunit in a canonical actin filament. MreB has an essential role in shape-maintenance of most rod-shaped bacteria. Unusually, MreB filaments assemble from two protofilaments in a flat and antiparallel arrangement. This non-polar architecture implies that both MreB filament ends are structurally identical. MreB filaments bind directly to membranes where they interact with both cytosolic and membrane proteins, thereby forming a key component of the elongasome. MreB filaments in cells are short and dynamic, moving around the long axis of rod-shaped cells, sensing curvature of the membrane and being implicated in peptidoglycan synthesis.

  6. Biologically inspired control and modeling of (biorobotic systems and some applications of fractional calculus in mechanics

    Directory of Open Access Journals (Sweden)

    Lazarević Mihailo P.

    2013-01-01

    Full Text Available In this paper, the applications of biologically inspired modeling and control of (biomechanical (nonredundant mechanisms are presented, as well as newly obtained results of author in mechanics which are based on using fractional calculus. First, it is proposed to use biological analog-synergy due to existence of invariant features in the execution of functional motion. Second, the model of (biomechanical system may be obtained using another biological concept called distributed positioning (DP, which is based on the inertial properties and actuation of joints of considered mechanical system. In addition, it is proposed to use other biological principles such as: principle of minimum interaction, which takes a main role in hierarchical structure of control and self-adjusting principle (introduce local positive/negative feedback on control with great amplifying, which allows efficiently realization of control based on iterative natural learning. Also, new, recently obtained results of the author in the fields of stability, electroviscoelasticity, and control theory are presented which are based on using fractional calculus (FC. [Projekat Ministarstva nauke Republike Srbije, br. 35006

  7. Bacterial populations and environmental factors controlling cellulose degradation in an acidic Sphagnum peat.

    Science.gov (United States)

    Pankratov, Timofey A; Ivanova, Anastasia O; Dedysh, Svetlana N; Liesack, Werner

    2011-07-01

    Northern peatlands represent a major global carbon store harbouring approximately one-third of the global reserves of soil organic carbon. A large proportion of these peatlands consists of acidic Sphagnum-dominated ombrotrophic bogs, which are characterized by extremely low rates of plant debris decomposition. The degradation of cellulose, the major component of Sphagnum-derived litter, was monitored in long-term incubation experiments with acidic (pH 4.0) peat extracts. This process was almost undetectable at 10°C and occurred at low rates at 20°C, while it was significantly accelerated at both temperature regimes by the addition of available nitrogen. Cellulose breakdown was only partially inhibited in the presence of cycloheximide, suggesting that bacteria participated in this process. We aimed to identify these bacteria by a combination of molecular and cultivation approaches and to determine the factors that limit their activity in situ. The indigenous bacterial community in peat was dominated by Alphaproteobacteria and Acidobacteria. The addition of cellulose induced a clear shift in the community structure towards an increase in the relative abundance of the Bacteroidetes. Increasing temperature and nitrogen availability resulted in a selective development of bacteria phylogenetically related to Cytophaga hutchinsonii (94-95% 16S rRNA gene sequence similarity), which densely colonized microfibrils of cellulose. Among isolates obtained from this community only some subdivision 1 Acidobacteria were capable of degrading cellulose, albeit at a very slow rate. These Acidobacteria represent indigenous cellulolytic members of the microbial community in acidic peat and are easily out-competed by Cytophaga-like bacteria under conditions of increased nitrogen availability. Members of the phylum Firmicutes, known to be key players in cellulose degradation in neutral habitats, were not detected in the cellulolytic community enriched at low pH. © 2011 Society for

  8. Biological control potential of the obligate parasite Pasteuria penetransagainst the root-knot nematode, Meloidogyne incognita infestation in Brinjal.

    Science.gov (United States)

    Kumari, N Swarna; Sivakumar, C V

    2005-01-01

    The efficacy of the obligate bacterial parasite, Pasteuria penetrans against the rootknot nematode, Meloidogyne incognita infestation was assessed in brinjal. The seedling pans with sterilized soil were inoculated with nematodes and root powder of P. penetrans were applied at different dosages viz., 0 x 10(6), 0.5 x 10(6) spores and 1 x 10(6) spores/pan. Seeds of brinjal cv Co2 were sown in the pans and seedlings were allowed to grow. The seedlings were transplanted to microplots containing sterilized soil. Observations on nematode infestation and plant growth were recorded at seedling, flowering, and fruiting stages. Nematode infestation was significantly reduced by P. penetrans treatment. There was 22, 75 and 86% reduction in nematode population of soil over control at seedling, flowering and fruiting stages, respectively, at higher spore density (1 x 10(6)). Egg mass production was decreased by 63, 78 and 89% over control at 35 (seedling), 100 (flowering) and 160 (fruiting) days after sowing respectively, at 1 x 10(6) spores treated soil. The parasitizing ability of P. penetrans increased with the age of the crop. At higher spore density the percentage of parasitization was increased from 52.0 (35 days after sowing) to 90.0 (160 days after sowing) %. At these stages of the crop, the spore load per juvenile also increased at the higher dose. The P. penetrans application enhanced the plant growth. The weight of the shoot was increased by 17.6% whereas root weight by 41.0% over the control at fruiting stage. The experimental results revealed the potential use of P. penetrans as biological control agent of M. incognita. Application of P. penetrans spores in the nursery is a good strategy since the mass multiplication is quite difficult.

  9. The role of evolutionary biology in research and control of liver flukes in Southeast Asia.

    Science.gov (United States)

    Echaubard, Pierre; Sripa, Banchob; Mallory, Frank F; Wilcox, Bruce A

    2016-09-01

    Stimulated largely by the availability of new technology, biomedical research at the molecular-level and chemical-based control approaches arguably dominate the field of infectious diseases. Along with this, the proximate view of disease etiology predominates to the exclusion of the ultimate, evolutionary biology-based, causation perspective. Yet, historically and up to today, research in evolutionary biology has provided much of the foundation for understanding the mechanisms underlying disease transmission dynamics, virulence, and the design of effective integrated control strategies. Here we review the state of knowledge regarding the biology of Asian liver Fluke-host relationship, parasitology, phylodynamics, drug-based interventions and liver Fluke-related cancer etiology from an evolutionary biology perspective. We consider how evolutionary principles, mechanisms and research methods could help refine our understanding of clinical disease associated with infection by Liver Flukes as well as their transmission dynamics. We identify a series of questions for an evolutionary biology research agenda for the liver Fluke that should contribute to an increased understanding of liver Fluke-associated diseases. Finally, we describe an integrative evolutionary medicine approach to liver Fluke prevention and control highlighting the need to better contextualize interventions within a broader human health and sustainable development framework. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The inception and evolution of a unique masters program in cancer biology, prevention and control.

    Science.gov (United States)

    Cousin, Carolyn; Blancato, Jan

    2010-09-01

    The University of the District of Columbia (UDC) and the Lombardi Comprehensive Cancer Center (LCCC), Georgetown University Medical Center established a Masters Degree Program in Cancer Biology, Prevention and Control at UDC that is jointly administered and taught by UDC and LCCC faculty. The goal of the Masters Degree Program is to educate students as master-level cancer professionals capable of conducting research and service in cancer biology, prevention, and control or to further advance the education of students to pursue doctoral studies. The Program's unique nature is reflected in its philosophy "the best cancer prevention and control researchers are those with a sound understanding of cancer biology". This program is a full-time, 2-year, 36-credit degree in which students take half of their coursework at UDC and half of their coursework at LCCC. During the second year, students are required to conduct research either at LCCC or UDC. Unlike most cancer biology programs, this unique Program emphasizes both cancer biology and cancer outreach training.

  11. The application of quality risk management to the bacterial endotoxins test: use of hazard analysis and critical control points.

    Science.gov (United States)

    Annalaura, Carducci; Giulia, Davini; Stefano, Ceccanti

    2013-01-01

    Risk analysis is widely used in the pharmaceutical industry to manage production processes, validation activities, training, and other activities. Several methods of risk analysis are available (for example, failure mode and effects analysis, fault tree analysis), and one or more should be chosen and adapted to the specific field where they will be applied. Among the methods available, hazard analysis and critical control points (HACCP) is a methodology that has been applied since the 1960s, and whose areas of application have expanded over time from food to the pharmaceutical industry. It can be easily and successfully applied to several processes because its main feature is the identification, assessment, and control of hazards. It can be also integrated with other tools, such as fishbone diagram and flowcharting. The aim of this article is to show how HACCP can be used to manage an analytical process, propose how to conduct the necessary steps, and provide data templates necessary to document and useful to follow current good manufacturing practices. In the quality control process, risk analysis is a useful tool for enhancing the uniformity of technical choices and their documented rationale. Accordingly, it allows for more effective and economical laboratory management, is capable of increasing the reliability of analytical results, and enables auditors and authorities to better understand choices that have been made. The aim of this article is to show how hazard analysis and critical control points can be used to manage bacterial endotoxins testing and other analytical processes in a formal, clear, and detailed manner.

  12. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  13. Potential for widespread application of biological control of stored-product pests

    DEFF Research Database (Denmark)

    Hansen, Lise Stengaard

    2007-01-01

    Biological control of stored product pests has substantial potential in Europe". This is essentially the conclusion of the activities of a European working group funded by the COST system, an intergovernmental networking system. Working group 4 of COST action 842 (2000-2005) focussed on biologica...... for these situations will contribute to ensuring that stored food products are protected from insect and mite pests using techniques that are safe for consumers, workers and the environment.......Biological control of stored product pests has substantial potential in Europe". This is essentially the conclusion of the activities of a European working group funded by the COST system, an intergovernmental networking system. Working group 4 of COST action 842 (2000-2005) focussed on biological...

  14. Biological Control of Diseases of Vegetables Grown Hydroponically in Thailand: Challenge and Opportunity.

    Science.gov (United States)

    Kanjanamaneesathian, Mana

    2015-01-01

    In Thailand, yield loss due to plant diseases in vegetables grown hydroponically is very high as a result of the growers` lack of knowledge for controlling diseases and their un- willingness to invest in setting-up the proper hydroponic system from the beginning. Severe root rot disease caused by Pythium spp. is frequent and can be anticipated in the hot climate in Thailand. This review focuses on the diseases in temperate lettuces which have been produced hydroponically and have been attacked by plant pathogens, particularly Pythium spp. Biological control of vegetable diseases grown hydroponically has been investigated in Thailand. Research is being carried out to identify effective strains of the antagonists, formulating the applicable products and delivering them appropriately to control the disease. Products of Bacillus subtilis, Chaetomium globosom and Trichoderma harzianum have been recommended for use to control diseases in vegetables grown hydroponically. Control efficacy of these products is varied as the biological products have been used by the growers in the paradigm of using chemical fungicide for disease control in hydroponic production system, overlooking the intrinsic characteristics of the biological control products. The recent patent, which minimizes the effects of sunlight and heat on the nutrient solution without the use of an external energy for cooling the nutrient, should be applied in producing hydroponic vegetables to mitigate poor plant growth and root rot disease outbreak in Thailand.

  15. Conserving archaeological sites as biological and historical resources in the Gulf of Mexico: the effects of crude oil and dispersant on the biodiversity and corrosion potential of shipwreck bacterial biofilms

    Science.gov (United States)

    Salerno, J. L.; Little, B.; Lee, J.; Ray, R.; Hamdan, L. J.

    2016-02-01

    There are more than 2,000 documented shipwrecks in the Gulf of Mexico. Historic shipwrecks are invaluable cultural resources, but also serve as artificial reefs, enhancing biodiversity in the deep sea. Oil and gas-related activities have the potential to impact shipwreck sites. An estimated 30% of the oil from the Deepwater Horizon spill was deposited in the deep-sea, in areas that contain shipwrecks. We conducted field and laboratory experiments to determine if crude oil, dispersed oil, and/or dispersant affect the community composition, metabolic function, and/or corrosion potential of microorganisms inhabiting shipwrecks. Platforms containing carbon steel coupons (CSC) (n = 34 per platform) were placed at impacted and non-impacted shipwrecks or into four experimental microcosm tanks. After a 2-week acclimation period, tanks were treated with crude oil and/or dispersant or received no treatment. CSC and seawater (SW) samples for bacterial genetic analysis were collected bi-weekly (at 16 wks for field samples). Proteobacteria dominated field and lab CSC bacterial communities (77-97% of sequences). Field CSC bacterial communities differed at each wreck site (P = 0.001), with oil-impacted sites differing from control sites. Lab CSC bacterial communities differed between all treatment groups (P = 0.005) and changed over the course of the experiment (P = 0.001). CSC bacterial species richness, diversity, and dominance increased with time across all treatments indicating the recruitment and establishment of microbial biofilms on CSCs. SW bacterial communities differed between treatment groups (P = 0.001), with the dispersant treatment being most dissimilar from all other treatments (P < 0.01), and changed over time (P = 0.001). Oil- and oil/dispersant-treated CSCs exhibited higher corrosion compared to dispersant and control treatments. These findings indicate that exposure to oil and/or dispersant may alter bacterial community composition and corrosion potential.

  16. Effect of selected essential oil plants on bacterial wilt disease ...

    African Journals Online (AJOL)

    SARAH

    2014-03-25

    Mar 25, 2014 ... March 2014. Published online at www.m.elewa.org on 30thJune 2014. ... Control of bacterial wilt is very difficult as there are no effective curative chemicals. ..... by Dr. S.T. Kariuki of Egerton University, Biological. Science ...

  17. Fundamental host range of Leptoypha hospita (Hemiptera: Tingidae), a potential biological control agent of Chinese privet

    Science.gov (United States)

    Yanzhuo Zhang; James L. Hanula; Scott Horn; Cera Jones; S. Kristine Braman; Jianghua Sun

    2016-01-01

    Chinese privet, Ligustrum sinense Lour., is an invasive shrub within riparian areas of the southeastern United States. Biological control is considered the most suitable management option for Chinese privet. The potential host range of the lace bug, Leptoypha hospita Drake et...

  18. Biological control in agro-systems by means of the handling of entomophagous insects

    International Nuclear Information System (INIS)

    Nicholls, Clara Ines; Altieri, Miguel A

    1998-01-01

    From several decades ago the importance of natural enemies of the noxious organisms has been recognized. Unfortunately the introduction of the biological control has not had the desired dimension. The indiscriminate use of biocides products has altered the biodiversity of the agro-ecosystem. The parasitoids and predators have suffered the noxious effects of the plaguicides. These natural enemies of the plagues play a momentous paper in the regulation of noxious insects population. The predators of the insecta class register in diverse orders and the abundance of species is impressive. But the knowledge of their importance is only partial. In many countries the kindness of these organisms has not been specified and does not protect them. In the case of parasitoids something similar occurs. It is say that their biotic diversity is incalculable but very few species are exploited. In these two groups rest the classic biological control projects. The successes in projects of biological control are recognized and they are enlarging in several countries but more impulse is required. Due to demands of a sustainable agricultural production it should support the biological control of plagues. In this document general looks on the topic are expounded

  19. Leveraging culture collections for the discovery and development of microbial biological control agents

    Science.gov (United States)

    The incorporation of living microbial biological control agents into integrated pest management programs is highly desirable because it reduces the use of chemical insecticides harmful to livestock, humans and the environment. In addition, it provides an alternative means to combat resistance to che...

  20. The potential use of lures for thrips biological control in greenhouses: practice and theory

    NARCIS (Netherlands)

    Teulon, D.A.J.; Davidson, M.M.; Nielsen, M.C.; Perry, N.B.; Tol, van R.W.H.M.; Kogel, de W.J.

    2008-01-01

    Exploiting the response of thrips pest species to odours has long been a goal for improving thrips pest management including biological control. Applications of attractants could include improved monitoring, push-pull (in conjunction with a repellent odour), lure and kill, and lure and infect

  1. Conservation Biological Control of Pests in the Molecular Era: New Opportunities to Address Old Constraints

    Science.gov (United States)

    Gurr, Geoff M.; You, Minsheng

    2016-01-01

    Biological control has long been considered a potential alternative to pesticidal strategies for pest management but its impact and level of use globally remain modest and inconsistent. A rapidly expanding range of molecular – particularly DNA-related – techniques is currently revolutionizing many life sciences. This review identifies a series of constraints on the development and uptake of conservation biological control and considers the contemporary and likely future influence of molecular methods on these constraints. Molecular approaches are now often used to complement morphological taxonomic methods for the identification and study of biological control agents including microbes. A succession of molecular techniques has been applied to ‘who eats whom’ questions in food-web ecology. Polymerase chain reaction (PCR) approaches have largely superseded immunological approaches such as enzyme-linked immunosorbent assay (ELISA) and now – in turn – are being overtaken by next generation sequencing (NGS)-based approaches that offer unparalleled power at a rapidly diminishing cost. There is scope also to use molecular techniques to manipulate biological control agents, which will be accelerated with the advent of gene editing tools, the CRISPR/Cas9 system in particular. Gene editing tools also offer unparalleled power to both elucidate and manipulate plant defense mechanisms including those that involve natural enemy attraction to attacked plants. Rapid advances in technology will allow the development of still more novel pest management options for which uptake is likely to be limited chiefly by regulatory hurdles. PMID:26793225

  2. Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

    International Nuclear Information System (INIS)

    1997-11-01

    The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference

  3. Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference. Refs, figs, tabs.

  4. Economic evaluation of the successful biological control of Azolla filiculoides in South Africa

    CSIR Research Space (South Africa)

    McConnachie, AJ

    2003-09-01

    Full Text Available that it was no longer considered a problem in South Africa. The results reflect the dynamics of biological control on site-specific survey information, and place higher benefit–cost ratios achieved in other national level studies in a better context. It also raises...

  5. The effect of initial density and parasitoid intergenerational survival rate on classical biological control

    International Nuclear Information System (INIS)

    Xiao Yanni; Tang Sanyi

    2008-01-01

    Models of biological control have a long history of theoretical development that have focused on the interaction of a parasitoid and its host. The host-parasitoid systems have identified several important and general factors affecting the long-term dynamics of interacting populations. However, much less is known about how the initial densities of host-parasitoid populations affect the biological control as well as the stability of host-parasitoid systems. To do this, the classical Nicholson-Bailey model with host self-regulation and parasitoid intergenerational survival rate is used to uncover the effect of initial densities on the successful biological control. The results indicate that the simplest Nicholson-Bailey model has various coexistence with a wide range of parameters, including boundary attractors where the parasitoid population is absent and interior attractors where host-parasitoid coexists. The final stable states of host-parasitoid populations depend on their initial densities as well as their ratios, and those results are confirmed by basins of attraction of initial densities. The results also indicate that the parasitoid intergenerational survival rate increases the stability of the host-parasitoid systems. Therefore, the present research can help us to further understand the dynamical behavior of host-parasitoid interactions, to improve the classical biological control and to make management decisions

  6. The Erythraeoidea (Trombidiformes: Prostigmata) as Biological Control Agents, with Special Reference to the Genus Balaustium

    NARCIS (Netherlands)

    Muñoz-Cárdenas, K.; Fuentes-Quintero, L.S.; Rueda-Ramirez, D.; Rodríguez, C.D.; Cantor, R.F.; Carrillo, D.; de Moraes, G.J.; Peña, J.E.

    2015-01-01

    Erythraeoidea is a widely distributed group with great potential for practical use in biological control programs, but whose study has been limited due to the complex life cycle that often includes alteration in feeding behaviour and habitat. Several associations of these mites to different species

  7. Potentials of biological control of plant diseases in the tropics | Ofor ...

    African Journals Online (AJOL)

    This paper highlights the various categories of biological control, which are employed in an Integrated Disease Management (IDM) scheme. These include conservation, classical biocontrol and augmentation. Also, the various types of biocontrol agents/agencies which are currently in use in various parts of the world like, ...

  8. Use of pupal parasitoids as biological control agents of filth flies on equine facilities

    Science.gov (United States)

    House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae), are common pests on horse farms. The use of pupal parasitoids as biological control agents for filth flies is becoming more popular on equine facilities; however, there is a lack of information on the e...

  9. Prospects for biological soil-borne disease control: application of indigenous versus synthetic microbiomes

    Science.gov (United States)

    Biological disease control of soil-borne plant diseases has traditionally employed the biopesticide approach whereby single strains or strain mixtures are introduced into production systems through inundative/inoculative release. The approach has significant barriers that have long been recognized,...

  10. Nuclear polyhedrosis virus as a biological control agent for Malacosoma americanum (Lepidoptera: Lasiocampidae)

    Science.gov (United States)

    R.A. Progar; M.J. Rinella; D. Fekedulegn; L. Butler

    2010-01-01

    In addition to damaging trees, the eastern tent caterpillar is implicated in early fetal loss and late-term abortion in horses. In a field study, we evaluated the potential biological control of the caterpillar using eastern tent caterpillar nuclear polyhedrosis virus (ETNPV), a naturally occurring virus that is nearly species-specific. Egg masses were hatched and...

  11. Assessing risks and benefits of floral supplements in conservation biological control

    NARCIS (Netherlands)

    Winkler, K.; Wackers, F.L.; Termorshuizen, A.J.; Lenteren, van J.C.

    2010-01-01

    The use of flowering field margins is often proposed as a method to support biological control in agro-ecosystems. In addition to beneficial insects, many herbivores depend on floral food as well. The indiscriminate use of flowering species in field margins can therefore lead to higher pest numbers.

  12. Host range of Secusio extensa (Lepidoptera: Arctiidae), and potential for biological control of Senecio madagascariensis (Asteraceae)

    Science.gov (United States)

    M. M. Ramadan; K. T. Murai; T. Johnson

    2010-01-01

    Secusio extensa (Lepidoptera: Arctiidae) was evaluated as a potential biological control agent for Madagascar fireweed, Senecio madagascariensis (Asteraceae), which has invaded over 400 000 acres of rangeland in the Hawaiian Islands and is toxic to cattle and horses. The moth was introduced from southeastern Madagascar...

  13. 41 CFR 101-42.1102-5 - Drugs, biologicals, and reagents other than controlled substances.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Drugs, biologicals, and reagents other than controlled substances. 101-42.1102-5 Section 101-42.1102-5 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS...

  14. Using matrix population models to inform biological control management of the wheat stem sawfly, Cephus cinctus

    Science.gov (United States)

    Demographic models are a powerful means of identifying vulnerable life stages of pest species and assessing the potential effectiveness of various management approaches in reducing pest population growth and spread. In a biological control context, such models can be used to focus foreign explorati...

  15. Biological control of Alternaria radicina in seed production of carrots with Ulocladium atrum

    NARCIS (Netherlands)

    Köhl, J.; Langerak, C.J.; Meekes, E.T.M.; Molhoek, W.M.L.

    2004-01-01

    Black rot of carrots is caused by seed-borne Alternaria radicina. Biological control of seed infestation by treatments applied to plants in flower during seed production with the fungal antagonist Ulocladium atrum was investigated in laboratory and field experiments resulting in a reduction of seed

  16. External rostral characters for differentiation of sexes in the biological control agent Mecinus janthinus (Coleoptera: Curculionidae)

    Science.gov (United States)

    Marjolein Schat; Sharlene E. Sing; Robert K. D. Peterson

    2007-01-01

    The stem-boring weevil, Mecinus janthinus (Germar), is a promising, well established classical biological control agent for the exotic invasive weed Dalmatian toadflax (Linaria dalmatica (L.) Mill.) (Scrophulariaceae). In this paper we present readily apparent rostral characters that can be used for sex differentiation of live stem-boring weevils at low magnification....

  17. Status of biological control projects on terrestrial invasive alien weeds in California

    Science.gov (United States)

    In cooperation with foreign scientists, we are currently developing new classical biological control agents for five species of invasive alien terrestrial weeds. Cape-Ivy. A gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae, have been favorably reviewed by TAG...

  18. Effects of biological control agents and exotic plant invasion on deer mouse populations

    Science.gov (United States)

    Yvette K. Ortega; Dean E. Pearson; Kevin S. McKelvey

    2004-01-01

    Exotic insects are commonly introduced as biological control agents to reduce densities of invasive exotic plants. Although current biocontrol programs for weeds take precautions to minimize ecological risks, little attention is paid to the potential nontarget effects of introduced food subsidies on native consumers. Previous research demonstrated that two gall flies (...

  19. Releases of natural enemies in Hawaii since 1980 for classical biological control of weeds

    Science.gov (United States)

    P. Conant; J. N. Garcia; M. T. Johnson; W. T. Nagamine; C. K. Hirayama; G. P. Markin; R. L. Hill

    2013-01-01

    A comprehensive review of biological control of weeds in Hawaii was last published in 1992, covering 74 natural enemy species released from 1902 through 1980. The present review summarizes releases of 21 natural enemies targeting seven invasive weeds from 1981 to 2010. These projects were carried out by Hawaii Department of Agriculture (HDOA), USDA Forest Service (USFS...

  20. Potential biological control agents for management of cogongrass (Cyperales: Poaceae) in the southeastern USA

    Science.gov (United States)

    Cogongrass, Imperata cylindrica (L.) Palisot de Beauvois (Cyperales: Poaceae), is a noxious invasive weed in the southeastern USA. Surveys for potential biological control agents of cogongrass were conducted in Asia and East Africa from 2013 to 2016. Several insect herbivores were found that may hav...

  1. Ex-ante analysis of economic returns from biological control of coconut mite in Tanzania

    NARCIS (Netherlands)

    Oleke, J.M.; Manyong, V.; Mignouna, D.; Isinika, A.; Mutabazi, K.; Hanna, R.; Sabelis, M.

    2013-01-01

    The coconut mite, Aceria guerreronis Keifer, has been identified as one of the pests that pose a threat to the coconut industry in Benin. The study presents the simulation results of the economic benefits of the biological control of coconut mites in Benin using a standard economic surplus model. In

  2. Biological control of fusarium wilt of tomato by antagonist fungi and ...

    African Journals Online (AJOL)

    Biological control of Fusarium oxysporum f. sp. lycopersici (FOL) causing wilt disease of tomato was studied in vitro as well as under pot conditions. Dual culture technique showed that Aspergillus niger, Penicillium citrinum, Penicillium sp. and Trichoderma harzianum inhibited the radial colony growth of the test pathogen.

  3. Genome sequences of three strains of Aspergillus flavus for the biological control of Aflatoxin

    Science.gov (United States)

    The genomes of three strains of Aspergillus flavus with demonstrated utility for the biological control of aflatoxin were sequenced. These sequences were assembled with MIRA and annotated with Augustus using A. flavus strain 3357 (NCBI EQ963472) as a reference. Each strain had a genome of 36.3 to ...

  4. Effective landscape scale management of Cirsium arvense (Canada thistle) utilizing biological control

    Science.gov (United States)

    G. P. Markin; D. Larson

    2013-01-01

    The stem mining weevil, Ceutorhynchus litura Fabricius, the gall forming fly, Urophora cardui L., and the seedhead weevil, Larinus planus Fabricius, were established as biological control agents on an 1800 hectare multiple-habitat wildlife refuge in northwestern Oregon in the mid-1990s. At the time, Canada thistle was the most wide spread, aggressive, and difficult...

  5. Status of biological control of the shrub gorse (Ulex europaeus) on the Island of Hawaii

    Science.gov (United States)

    G. P. Markin; P. Conant

    2013-01-01

    On the island of Hawaii, gorse (Ulex europaeus L.) is limited to an isolated core infestation of approximately 2000 hectares with scattered plants and small patches in the surrounding 10,000 hectares. Between 1985 and 2000, seven biological control agents were introduced, five of which successfully established. By 2000, their combined impact had reduced the yearly...

  6. Integration of biological control and transgenic insect protection for mitigation of mycotoxins in corn

    Science.gov (United States)

    Biological control is known to be effective in reducing aflatoxin contamination of corn and some transgenic corn hybrids incur greatly reduced damage from corn earworm (Helicoverpa zea). We conducted seven field trials over two years to test the hypothesis that transgenic insect protection and biol...

  7. Evaluation of biological control of fusarium wilt in gerbera with Trichoderma asperellum

    OpenAIRE

    Daiani Brandler; Luan Junior Divensi; Rodrigo José Tonin; Thalita Pedrozo Pilla; Ines Rezendes; Paola Mendes Milanesi

    2017-01-01

    The increase in flower cultivation in recent years has been reflecting the higher incidence of soil pathogens that can cause serious problems. This study aimed to evaluate the biological control of Fusarium wilt in gerbera with Trichoderma asperellum. The evaluated treatments were: T1) Control, only sterile substrate; T2) Substrate + Fusarium oxysporum; T3) Substrate + Fusarium oxysporum + Trichoderma asperellum; and T4) Substrate + Trichoderma asperellum. For this, the pathogen was isolated ...

  8. Combining chemoinformatics with bioinformatics: in silico prediction of bacterial flavor-forming pathways by a chemical systems biology approach "reverse pathway engineering".

    Science.gov (United States)

    Liu, Mengjin; Bienfait, Bruno; Sacher, Oliver; Gasteiger, Johann; Siezen, Roland J; Nauta, Arjen; Geurts, Jan M W

    2014-01-01

    The incompleteness of genome-scale metabolic models is a major bottleneck for systems biology approaches, which are based on large numbers of metabolites as identified and quantified by metabolomics. Many of the revealed secondary metabolites and/or their derivatives, such as flavor compounds, are non-essential in metabolism, and many of their synthesis pathways are unknown. In this study, we describe a novel approach, Reverse Pathway Engineering (RPE), which combines chemoinformatics and bioinformatics analyses, to predict the "missing links" between compounds of interest and their possible metabolic precursors by providing plausible chemical and/or enzymatic reactions. We demonstrate the added-value of the approach by using flavor-forming pathways in lactic acid bacteria (LAB) as an example. Established metabolic routes leading to the formation of flavor compounds from leucine were successfully replicated. Novel reactions involved in flavor formation, i.e. the conversion of alpha-hydroxy-isocaproate to 3-methylbutanoic acid and the synthesis of dimethyl sulfide, as well as the involved enzymes were successfully predicted. These new insights into the flavor-formation mechanisms in LAB can have a significant impact on improving the control of aroma formation in fermented food products. Since the input reaction databases and compounds are highly flexible, the RPE approach can be easily extended to a broad spectrum of applications, amongst others health/disease biomarker discovery as well as synthetic biology.

  9. Shaping bacterial population behavior through computer-interfaced control of individual cells.

    Science.gov (United States)

    Chait, Remy; Ruess, Jakob; Bergmiller, Tobias; Tkačik, Gašper; Guet, Călin C

    2017-11-16

    Bacteria in groups vary individually, and interact with other bacteria and the environment to produce population-level patterns of gene expression. Investigating such behavior in detail requires measuring and controlling populations at the single-cell level alongside precisely specified interactions and environmental characteristics. Here we present an automated, programmable platform that combines image-based gene expression and growth measurements with on-line optogenetic expression control for hundreds of individual Escherichia coli cells over days, in a dynamically adjustable environment. This integrated platform broadly enables experiments that bridge individual and population behaviors. We demonstrate: (i) population structuring by independent closed-loop control of gene expression in many individual cells, (ii) cell-cell variation control during antibiotic perturbation, (iii) hybrid bio-digital circuits in single cells, and freely specifiable digital communication between individual bacteria. These examples showcase the potential for real-time integration of theoretical models with measurement and control of many individual cells to investigate and engineer microbial population behavior.

  10. Architecture and inherent robustness of a bacterial cell-cycle control system.

    Science.gov (United States)

    Shen, Xiling; Collier, Justine; Dill, David; Shapiro, Lucy; Horowitz, Mark; McAdams, Harley H

    2008-08-12

    A closed-loop control system drives progression of the coupled stalked and swarmer cell cycles of the bacterium Caulobacter crescentus in a near-mechanical step-like fashion. The cell-cycle control has a cyclical genetic circuit composed of four regulatory proteins with tight coupling to processive chromosome replication and cell division subsystems. We report a hybrid simulation of the coupled cell-cycle control system, including asymmetric cell division and responses to external starvation signals, that replicates mRNA and protein concentration patterns and is consistent with observed mutant phenotypes. An asynchronous sequential digital circuit model equivalent to the validated simulation model was created. Formal model-checking analysis of the digital circuit showed that the cell-cycle control is robust to intrinsic stochastic variations in reaction rates and nutrient supply, and that it reliably stops and restarts to accommodate nutrient starvation. Model checking also showed that mechanisms involving methylation-state changes in regulatory promoter regions during DNA replication increase the robustness of the cell-cycle control. The hybrid cell-cycle simulation implementation is inherently extensible and provides a promising approach for development of whole-cell behavioral models that can replicate the observed functionality of the cell and its responses to changing environmental conditions.

  11. Improving the cost-effectiveness, trade and safety of biological control for agricultural insect pests using nuclear techniques

    Science.gov (United States)

    If appropriately applied, biological control offers one of the most promising, environmentally sound, and sustainable control tactics for arthropod pests and weeds for application as part of an integrated pest management (IPM) approach. Public support for biological control as one of the preferred m...

  12. Do biological-based strategies hold promise to biofouling control in MBRs?

    KAUST Repository

    Malaeb, Lilian

    2013-10-01

    Biofouling in membrane bioreactors (MBRs) remains a primary challenge for their wider application, despite the growing acceptance of MBRs worldwide. Research studies on membrane fouling are extensive in the literature, with more than 200 publications on MBR fouling in the last 3 years; yet, improvements in practice on biofouling control and management have been remarkably slow. Commonly applied cleaning methods are only partially effective and membrane replacement often becomes frequent. The reason for the slow advancement in successful control of biofouling is largely attributed to the complex interactions of involved biological compounds and the lack of representative-for-practice experimental approaches to evaluate potential effective control strategies. Biofouling is driven by microorganisms and their associated extra-cellular polymeric substances (EPS) and microbial products. Microorganisms and their products convene together to form matrices that are commonly treated as a black box in conventional control approaches. Biological-based antifouling strategies seem to be a promising constituent of an effective integrated control approach since they target the essence of biofouling problems. However, biological-based strategies are in their developmental phase and several questions should be addressed to set a roadmap for translating existing and new information into sustainable and effective control techniques. This paper investigates membrane biofouling in MBRs from the microbiological perspective to evaluate the potential of biological-based strategies in offering viable control alternatives. Limitations of available control methods highlight the importance of an integrated anti-fouling approach including biological strategies. Successful development of these strategies requires detailed characterization of microorganisms and EPS through the proper selection of analytical tools and assembly of results. Existing microbiological/EPS studies reveal a number of

  13. Cardiocladius oliffi (Diptera: Chironomidae as a potential biological control agent against Simulium squamosum (Diptera: Simuliidae

    Directory of Open Access Journals (Sweden)

    Wilson Michael D

    2009-04-01

    Full Text Available Abstract Background The control of onchocerciasis in the African region is currently based mainly on the mass drug administration of ivermectin. Whilst this has been found to limit morbidity, it does not stop transmission. In the absence of a macrofilaricide, there is a need for an integrated approach for disease management, which includes vector control. Vector control using chemical insecticides is expensive to apply, and therefore the use of other measures such as biological control agents is needed. Immature stages of Simulium squamosum, reared in the laboratory from egg masses collected from the field at Boti Falls and Huhunya (River Pawnpawn in Ghana, were observed to be attacked and fed upon by larvae of the chironomid Cardiocladius oliffi Freeman, 1956 (Diptera: Chironomidae. Methods Cardiocladius oliffi was successfully reared in the rearing system developed for S. damnosum s.l. and evaluated for its importance as a biological control agent in the laboratory. Results Even at a ratio of one C. oliffi to five S. squamosum, they caused a significant decrease in the number of adult S. squamosum emerging from the systems (treatments. Predation was confirmed by the amplification of Simulium DNA from C. oliffi observed to have fed on S. squamosum pupae. The study also established that the chironomid flies could successfully complete their development on a fish food diet only. Conclusion Cardiocladius oliffi has been demonstrated as potential biological control agent against S. squamosum.

  14. Hybridization of an invasive shrub affects tolerance and resistance to defoliation by a biological control agent

    Science.gov (United States)

    Williams, Wyatt I.; Friedman, Jonathan M.; Gaskin, John F.; Norton, Andrew P.

    2014-01-01

    Evolution has contributed to the successful invasion of exotic plant species in their introduced ranges, but how evolution affects particular control strategies is still under evaluation. For instance, classical biological control, a common strategy involving the utilization of highly specific natural enemies to control exotic pests, may be negatively affected by host hybridization because of shifts in plant traits, such as root allocation or chemical constituents. We investigated introgression between two parent species of the invasive shrub tamarisk (Tamarix spp.) in the western United States, and how differences in plant traits affect interactions with a biological control agent. Introgression varied strongly with latitude of origin and was highly correlated with plant performance. Increased levels of T. ramosissima introgression resulted in both higher investment in roots and tolerance to defoliation and less resistance to insect attack. Because tamarisk hybridization occurs predictably on the western U.S. landscape, managers may be able to exploit this information to maximize control efforts. Genetic differentiation in plant traits in this system underpins the importance of plant hybridization and may explain why some biological control releases are more successful than others.

  15. Strengthening cancer biology research, prevention, and control while reducing cancer disparities: student perceptions of a collaborative master's degree program in cancer biology, preventions, and control.

    Science.gov (United States)

    Jillson, I A; Cousin, C E; Blancato, J K

    2013-09-01

    This article provides the findings of a survey of previous and current students in the UDC/GU-LCCC master's degree program. This master's degree program, Cancer Biology, Prevention, and Control is administered and taught jointly by faculty of a Minority Serving Institution, the University of the District of Columbia, and the Lombardi Comprehensive Cancer Center to incorporate the strengths of a community-based school with a research intensive medical center. The program was initiated in 2008 through agreements with both University administrations and funding from the National Cancer Institute. The master's degree program is 36 credits with a focus on coursework in biostatistics, epidemiology, tumor biology, cancer prevention, medical ethics, and cancer outreach program design. For two semesters during the second year, students work full-time with a faculty person on a laboratory or outreach project that is a requirement for graduation. Students are supported and encouraged to transition to a doctoral degree after they obtain the master's and many of them are currently in doctorate programs. Since the inception of the program, 45 students have initiated the course of study, 28 have completed the program, and 13 are currently enrolled in the program. The survey was designed to track the students in their current activities, as well as determine which courses, program enhancements, and research experiences were the least and most useful, and to discern students' perceptions of knowledge acquired on various aspects of Cancer Biology Prevention, and Control Master's Program. Thirty of the 35 individuals to whom email requests were sent responded to the survey, for a response rate of 85.7%. The results of this study will inform the strengthening of the Cancer Biology program by the Education Advisory Committee. They can also be used in the development of comparable collaborative master's degree programs designed to address the significant disparities in prevalence of

  16. Bacterial endogenous endophthalmitis in Vietnam: a randomized controlled trial comparing vitrectomy with silicone oil versus vitrectomy alone

    Directory of Open Access Journals (Sweden)

    Do T

    2014-08-01

    Full Text Available Tan Do,1 Do N Hon,1 Tin Aung,2 Nguyen DTN Hien,1 Claude L Cowan Jr3 1Vietnam National Institute of Ophthalmology, Hanoi, Vietnam; 2Singapore National Eye Center, Singapore; 3Georgetown University Medical Center, Washington, DC, USA Background/aims: To compare treatment outcomes with and without silicone oil tamponade in patients undergoing pars plana vitrectomy (PPV for severe endogenous bacterial endophthalmitis (BEE. Methods: One hundred and eight consecutive patients with severe BEE (defined by the absence of pupil red reflex at presentation and/or dense vitreous opacity on ultrasound and no improvement after 24–36 hours of medical treatment were randomly assigned to two treatment groups: Group 1, standard PPV with intravitreal antibiotics; and Group 2, PPV with intravitreal antibiotics and silicone tamponade. Overall success was defined as: a visual acuity ≥ count fingers at 1 meter, with an attached retina, and no intraocular oil. Results: Fifty three patients were randomized to Group 1 and 55 patients to Group 2. The mean age of study subjects was 32 years and baseline clinical characteristics were similar in both groups. At the final follow-up visit at 9 months, the overall success rate of Group 2 (67.3% was significantly better than Group 1 (43.4%; P=0.01. There were also fewer devastating complications (such as inoperable retinal detachment, phthisis bulbi in Group 2 compared with Group 1 (21.8% versus 43.4%; P=0.01. Conclusion: The outcome at 9 months of patients with BEE treated by vitrectomy with silicone oil was better than those treated by vitrectomy alone. Keywords: bacterial endogenous endophthalmitis, vitrectomy, silicone oil endotamponade, randomized controlled trial

  17. Genetic control of growth traits and inheritance of resistance to bacterial leaf scorch in American Sycamore

    Science.gov (United States)

    J.P. Adams; R. J. Rousseau; T. D. Leininger

    2012-01-01

    Open-pollinated progeny tests of American sycamore (Platanus occidentalis L.), which included 55 open-pollinated families selected from several prior Westvaco progeny tests and seed orchards and six control-pollinated families were established in 2002 and 2003. The half-sibling families were planted at two sites in western Kentucky and southeastern...

  18. CISH controls bacterial burden early after infection with Mycobacterium tuberculosis in mice.

    Science.gov (United States)

    Carow, Berit; Gao, Yu; Terán, Graciela; Yang, Xuexian O; Dong, Chen; Yoshimura, Akihiko; Rottenberg, Martin E

    2017-12-01

    CISH gene has been associated with increased susceptibility to human tuberculosis. We found that cish -/- mice had higher M. tuberculosis load in spleens and lungs up to 2.5 weeks after infection but not later compared to controls. Cish mRNA levels were increased in lungs at early and late time points after M. tuberculosis infection. In relation, the titers of inos and tnf mRNA in lungs were reduced early after infection of cish -/- mice. The transfer of cish -/- and control T cells conferred rag1 -/- mice similar protection to infection with M. tuberculosis. Macrophages showed increased cish mRNA levels after M. tuberculosis infection in vitro. However, mycobacterial uptake and growth in cish -/- and control macrophages was similar. Thus, we here show that CISH mediates control of M. tuberculosis in mice early after infection via regulation of innate immune mechanisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  20. Biological control of fruit flies (Diptera: Tephritidae) through parasitoid augmentative releases: Current status

    International Nuclear Information System (INIS)

    Montoya, Pablo; Liedo, Pablo

    2000-01-01

    Fruit flies are among the main pests affecting the world fruit industry (Aluja 1993). Bait sprays have traditionally been used successfully to control them; however, the side effects on the environment and health hazards commonly associated with pesticides, have resulted in strong public opposition to the use of bait sprays. This is particularly so when sprays are applied in urban areas or in coffee plantations where, although Medflies are present, they do not pose a danger to crops. Alternative methods that are effective and environmental friendly to suppress fruit fly populations are highly desirable. Biological control, the use of natural enemies to suppress pest populations, represents such an alternative. Some of the most successful cases of biological control are the control of Iceria purchasi Maskell (Homoptera: Margarodidae) by Rodolia cardinalis Mulsant (Coleoptera: Coccinellidae) in California (De Bach 1968, van den Bosch et al. 1982), and the control of Aleurocanthus woglumi Ashby (Homoptera: Aleyrodidae) mainly by Encarsia (=Prospaltella) opulenta Silv. (Hymenoptera: Aphelinidae) in Mexico (Jimenez 1961, 1971), both using the classical approach. However, this approach has been limited to certain conditions of environmental stability and biodiversity which are only found in a few ecosystems. Other factors, such as types of pests, the economic threshold and product quality requirements represent additional limitations. The best option in many cases could be augmentative biological control, which could overcome some of the deficiencies of the classical approach (Sivinski 1996). According to Knipling (1992) and Barclay (1987), augmentative biological control can be considered as a formal alternative for suppressing pest populations and even for use in eradication programmes, after integration with the sterile insect technique (SIT). In this approach, mass production of natural enemies is required and this production has to be cost effective

  1. Card9 mediates susceptibility to intestinal pathogens through microbiota modulation and control of bacterial virulence.

    Science.gov (United States)

    Lamas, Bruno; Michel, Marie-Laure; Waldschmitt, Nadine; Pham, Hang-Phuong; Zacharioudaki, Vassiliki; Dupraz, Louise; Delacre, Myriam; Natividad, Jane M; Costa, Gregory Da; Planchais, Julien; Sovran, Bruno; Bridonneau, Chantal; Six, Adrien; Langella, Philippe; Richard, Mathias L; Chamaillard, Mathias; Sokol, Harry

    2017-08-08

    In association with innate and adaptive immunity, the microbiota controls the colonisation resistance against intestinal pathogens. Caspase recruitment domain 9 ( CARD9 ), a key innate immunity gene, is required to shape a normal gut microbiota. Card9 -/- mice are more susceptible to the enteric mouse pathogen Citrobacter rodentium that mimics human infections with enteropathogenic and enterohaemorrhagic Escherichia coli . Here, we examined how CARD9 controls C. rodentium infection susceptibility through microbiota-dependent and microbiota-independent mechanisms. C. rodentium infection was assessed in conventional and germ-free (GF) wild-type (WT) and Card9 -/- mice. To explore the impact of Card9 -/- microbiota in infection susceptibility, GF WT mice were colonised with WT (WT→GF) or Card9 -/- ( Card9 -/- →GF) microbiota before C. rodentium infection. Microbiota composition was determined by 16S rDNA gene sequencing. Inflammation severity was determined by histology score and lipocalin level. Microbiota-host immune system interactions were assessed by quantitative PCR analysis. CARD9 controls pathogen virulence in a microbiota-independent manner by supporting a specific humoral response. Higher susceptibility to C. rodentium -induced colitis was observed in Card9 -/- →GF mice. The microbiota of Card9 -/- mice failed to outcompete the monosaccharide-consuming C. rodentium , worsening the infection severity. A polysaccharide-enriched diet counteracted the ecological advantage of C. rodentium and the defective pathogen-specific antibody response in Card9 -/- mice. CARD9 modulates the susceptibility to intestinal infection by controlling the pathogen virulence in a microbiota-dependent and microbiota-independent manner. Genetic susceptibility to intestinal pathogens can be overridden by diet intervention that restores humoural immunity and a competing microbiota. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017

  2. The biological control of aquatic weeds in South Africa: Current status and future challenges

    Directory of Open Access Journals (Sweden)

    Martin P. Hill

    2017-03-01

    Full Text Available Background: Aquatic ecosystems in South Africa are prone to invasion by several invasive alien aquatic weeds, most notably, Eichhornia crassipes (Mart. Solms-Laub. (Pontederiaceae (water hyacinth; Pistia stratiotes L. (Araceae (water lettuce; Salvinia molesta D.S. Mitch. (Salviniaceae (salvinia; Myriophyllum aquaticum (Vell. Conc. Verd. (parrot’s feather; and Azolla filiculoides Lam. (Azollaceae (red water fern. Objective: We review the biological control programme on waterweeds in South Africa. Results: Our review shows significant reductions in the extent of invasions, and a return on biodiversity and socio-economic benefits through the use of this method. These studies provide justification for the control of widespread and emerging freshwater invasive alien aquatic weeds in South Africa. Conclusions: The long-term management of alien aquatic vegetation relies on the correct implementation of biological control for those species already in the country and the prevention of other species entering South Africa.

  3. Commercial Biological Control Agents Targeted Against Plant-Parasitic Root-knot Nematodes

    Directory of Open Access Journals (Sweden)

    Marie-Stéphane Tranier

    2014-12-01

    Full Text Available Root-knot nematodes are microscopic round worms, which cause severe agricultural losses. Their attacks affect the productivity by reducing the amount and the caliber of the fruits. Chemical control is widely used, but biological control appears to be a better solution, mainly using microorganisms to reduce the quantity of pests infecting crops. Biological control is developing gradually, and with time, more products are being marketed worldwide. They can be formulated with bacteria, viruses or with filamentous fungi, which can destroy and feed on phytoparasitic nematodes. To be used by the farmers, biopesticides must be legalized by the states, which has led to the establishment of a legal framework for their use, devised by various governmental organizations.

  4. [Physicians' knowledge in Israel on the biology and control of head lice].

    Science.gov (United States)

    Mumcuoglu, Kosta Y; Mumcuoglu, Michael; Danilevich, Maria; Gilead, Leon

    2008-10-01

    Health providers such as physicians, nurses and pharmacists should be knowledgeable about the biology of head lice and the ways to control them effectively, in order to reduce the proportion of children infested with head lice. To evaluate the knowledge of physicians in Israel on the biology and epidemiology of lice, as well as their experience with infested individuals and their preferences for diagnosis, prophylaxis and control. An anonymous questionnaire with 37 questions was used. The first 20 questions addressed the general knowledge of physicians on lice biology and control, while the remaining 17 questions were related to their personal experience with lice and louse treatment. Out of 273 physicians interviewed 66.8% had good knowledge of lice, while the remaining 33.2% had some knowledge on lice. The difference between the groups of physicians with medium and good knowledge on lice was borderline significant (P=0.0722), with the dermatologists borderline significantly less knowledgeable than the rest (P=0.0765). Significant differences were found between those physicians with 4-6 or 11-20 years of professional experience and the remaining groups (twice Pbiology and control was higher than male physicians (39.4% and 29.4%, respectively), the differences were borderline significant (P=0.09). Pediatricians and dermatologists examined significantly more children than family physicians and general practitioners (P control of head louse infestations.

  5. Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism.

    Science.gov (United States)

    Wu, Si; Ge, Xi; Lv, Zhixin; Zhi, Zeyong; Chang, Zengyi; Zhao, Xin Sheng

    2011-09-15

    The OMPs (outer membrane proteins) of Gram-negative bacteria have to be translocated through the periplasmic space before reaching their final destination. The aqueous environment of the periplasmic space and high permeability of the outer membrane engender such a translocation process inevitably challenging. In Escherichia coli, although SurA, Skp and DegP have been identified to function in translocating OMPs across the periplasm, their precise roles and their relationship remain to be elucidated. In the present paper, by using fluorescence resonance energy transfer and single-molecule detection, we have studied the interaction between the OMP OmpC and these periplasmic quality control factors. The results of the present study reveal that the binding rate of OmpC to SurA or Skp is much faster than that to DegP, which may lead to sequential interaction between OMPs and different quality control factors. Such a kinetic partitioning mechanism for the chaperone-substrate interaction may be essential for the quality control of the biogenesis of OMPs.

  6. Combination of cupric ion with hydroxylamine and hydrogen peroxide for the control of bacterial biofilms on RO membranes.

    Science.gov (United States)

    Lee, Hye-Jin; Kim, Hyung-Eun; Lee, Changha

    2017-03-01

    Combinations of Cu(II) with hydroxylamine (HA) and hydrogen peroxide (H 2 O 2 ) (i.e., Cu(II)/HA, Cu(II)/H 2 O 2 , and Cu(II)/HA/H 2 O 2 systems) were investigated for the control of P. aeruginosa biofilms on reverse osmosis (RO) membranes. These Cu(II)-based disinfection systems effectively inactivated P. aeruginosa cells, exhibiting different behaviors depending on the state of bacterial cells (planktonic or biofilm) and the condition of biofilm growth and treatment (normal or pressurized condition). The Cu(II)/HA and Cu(II)/HA/H 2 O 2 systems were the most effective reagents for the inactivation of planktonic cells. However, these systems were not effective in inactivating cells in biofilms on the RO membranes possibly due to the interactions of Cu(I) with extracellular polymeric substances (EPS), where biofilms were grown and treated in center for disease control (CDC) reactors. Different from the results using CDC reactors, in a pressurized cross-flow RO filtration unit, the Cu(II)/HA/H 2 O 2 treatment significantly inactivated biofilm cells formed on the RO membranes, successfully recovering the permeate flux reduced by the biofouling. The pretreatment of feed solutions by Cu(II)/HA and Cu(II)/HA/H 2 O 2 systems (applied before the biofilm formation) effectively mitigated the permeate flux decline by preventing the biofilm growth on the RO membranes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Aromatic inhibitors derived from ammonia-pretreated lignocellulose hinder bacterial ethanologenesis by activating regulatory circuits controlling inhibitor efflux and detoxification

    Directory of Open Access Journals (Sweden)

    David H. Keating

    2014-08-01

    Full Text Available Efficient microbial conversion of lignocellulosic hydrolysates to biofuels is a key barrier to the economically viable deployment of lignocellulosic biofuels. A chief contributor to this barrier is the impact on microbial processes and energy metabolism of lignocellulose-derived inhibitors, including phenolic carboxylates, phenolic amides (for ammonia-pretreated biomass, phenolic aldehydes, and furfurals. To understand the bacterial pathways induced by inhibitors present in ammonia-pretreated biomass hydrolysates, which are less well studied than acid-pretreated biomass hydrolysates, we developed and exploited synthetic mimics of ammonia-pretreated corn stover hydrolysate (ACSH. To determine regulatory responses to the inhibitors normally present in ACSH, we measured transcript and protein levels in an Escherichia coli ethanologen using RNA-seq and quantitative proteomics during fermentation to ethanol of synthetic hydrolysates containing or lacking the inhibitors. Our study identified four major regulators mediating these responses, the MarA/SoxS/Rob network, AaeR, FrmR, and YqhC. Induction of these regulons was correlated with a reduced rate of ethanol production, buildup of pyruvate, depletion of ATP and NAD(PH, and an inhibition of xylose conversion. The aromatic aldehyde inhibitor 5-hydroxymethylfurfural appeared to be reduced to its alcohol form by the ethanologen during fermentation, whereas phenolic acid and amide inhibitors were not metabolized. Together, our findings establish that the major regulatory responses to lignocellulose-derived inhibitors are mediated by transcriptional rather than translational regulators, suggest that energy consumed for inhibitor efflux and detoxification may limit biofuel production, and identify a network of regulators for future synthetic biology efforts.

  8. Expression and characterization of antimicrobial peptides Retrocyclin-101 and Protegrin-1 in chloroplasts to control viral and bacterial infections.

    Science.gov (United States)

    Lee, Seung-Bum; Li, Baichuan; Jin, Shuangxia; Daniell, Henry

    2011-01-01

    Retrocyclin-101 (RC101) and Protegrin-1 (PG1) are two important antimicrobial peptides that can be used as therapeutic agents against bacterial and/or viral infections, especially those caused by the HIV-1 or sexually transmitted bacteria. Because of their antimicrobial activity and complex secondary structures, they have not yet been produced in microbial systems and their chemical synthesis is prohibitively expensive. Therefore, we created chloroplast transformation vectors with the RC101 or PG1 coding sequence, fused with GFP to confer stability, furin or Factor Xa cleavage site to liberate the mature peptide from their fusion proteins and a His-tag to aid in their purification. Stable integration of RC101 into the tobacco chloroplast genome and homoplasmy were confirmed by Southern blots. RC101 and PG1 accumulated up to 32%-38% and 17%∼26% of the total soluble protein. Both RC101 and PG1 were cleaved from GFP by corresponding proteases in vitro, and Factor Xa-like protease activity was observed within chloroplasts. Confocal microscopy studies showed location of GFP fluorescence within chloroplasts. Organic extraction resulted in 10.6-fold higher yield of RC101 than purification by affinity chromatography using His-tag. In planta bioassays with Erwinia carotovora confirmed the antibacterial activity of RC101 and PG1 expressed in chloroplasts. RC101 transplastomic plants were resistant to tobacco mosaic virus infections, confirming antiviral activity. Because RC101 and PG1 have not yet been produced in other cell culture or microbial systems, chloroplasts can be used as bioreactors for producing these proteins. Adequate yield of purified antimicrobial peptides from transplastomic plants should facilitate further preclinical studies. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology and Blackwell Publishing Ltd.

  9. Design, modeling and control of a pneumatically actuated manipulator inspired by biological continuum structures

    International Nuclear Information System (INIS)

    Kang, Rongjie; Zheng Tianjiang; Guglielmino, Emanuele; Caldwell, Darwin G; Branson, David T

    2013-01-01

    Biological tentacles, such as octopus arms, have entirely flexible structures and virtually infinite degrees of freedom (DOF) that allow for elongation, shortening and bending at any point along the arm length. The amazing dexterity of biological tentacles has driven the growing implementation of continuum manipulators in robotic systems. This paper presents a pneumatic manipulator inspired by biological continuum structures in some of their key features and functions, such as continuum morphology, intrinsic compliance and stereotyped motions with hyper redundant DOF. The kinematics and dynamics of the manipulator are formulated and identified, and a hierarchical controller taking inspiration from the structure of an octopus nervous system is used to relate desired stereotyped motions to individual actuator inputs. Simulations and experiments are carried out to validate the model and prototype where good agreement was found between the two. (paper)

  10. Efficacy of a commercial probiotic relative to oxytetracycline as Gram-negative bacterial control agents in a rotifer (Brachionus plicatilis) batch culture

    Science.gov (United States)

    Two trials were conducted to evaluate two gram-negative bacterial control strategies in batch cultures of the rotifer Brachionus plicatilis. In the first trial, rotifers at an initial density of 47/mL were cultured for 5 d and dosed with a 10-mg/L solution of either oxytetracycline or a commercial p...

  11. The quality control for biological-shield heavy concrete construction of nuclear power project

    International Nuclear Information System (INIS)

    Sun Hongjun; Ma Xinchao

    2012-01-01

    The paper introduces the function and characteristics of biological protective heavy-concrete, and its main application scope and role in Fangjiashan nuclear power project. From the aspects of raw material selection, mixing ratio test, heavy concrete production, the paper discusses the main control points of heavy concrete construction process, points out the basic characteristics of heavy concrete construction, and put forward measures to prevent density non-uniformity during heavy concrete construction and to control slump during transportation. Results prove that reasonable construction process control can assure the engineering quality. (authors)

  12. Energy-based control for a biologically inspired hexapod robot with rolling locomotion

    Directory of Open Access Journals (Sweden)

    Takuma Nemoto

    2015-04-01

    Full Text Available This paper presents an approach to control rolling locomotion on the level ground with a biologically inspired hexapod robot. For controlling rolling locomotion, a controller which can compensate energy loss with rolling locomotion of the hexapod robot is designed based on its dynamic model. The dynamic model describes the rolling locomotion which is limited to planar one by an assumption that the hexapod robot does not fall down while rolling and influences due to collision and contact with the ground, and it is applied for computing the mechanical energy of the hexapod robot and a plant for a numerical simulation. The numerical simulation of the rolling locomotion on the level ground verifies the effectiveness of the proposed controller. The simulation results show that the hexapod robot can perform the rolling locomotion with the proposed controller. In conclusion, it is shown that the proposed control approach is effective in achieving the rolling locomotion on the level ground.

  13. Polymorphism in Bacterial Flagella Suspensions

    Science.gov (United States)

    Schwenger, Walter J.

    Bacterial flagella are a type of biological polymer studied for its role in bacterial motility and the polymorphic transitions undertaken to facilitate the run and tumble behavior. The naturally rigid, helical shape of flagella gives rise to novel colloidal dynamics and material properties. This thesis studies methods in which the shape of bacterial flagella can be controlled using in vitro methods and the changes the shape of the flagella have on both single particle dynamics and bulk material properties. We observe individual flagellum in both the dilute and semidilute regimes to observe the effects of solvent condition on the shape of the filament as well as the effect the filament morphology has on reptation through a network of flagella. In addition, we present rheological measurements showing how the shape of filaments effects the bulk material properties of flagellar suspensions. We find that the individual particle dynamics in suspensions of flagella can vary with geometry from needing to reptate linearly via rotation for helical filaments to the prevention of long range diffusion for block copolymer filaments. Similarly, for bulk material properties of flagella suspensions, helical geometries show a dramatic enhancement in elasticity over straight filaments while block copolymers form an elastic gel without the aid of crosslinking agents.

  14. Biological control against the carob moth Ectomyelois ceratoniae in oases and in packing houses in Tunisia

    International Nuclear Information System (INIS)

    Dhouibi, M.H.; Cheikh, T.; Cherni, M.; Ben Moussa, I.; Hawlitsky, N.; Zaaraoui, H.; Krisaane, T.

    2000-01-01

    The carob moth, Ectomyelois ceratoniae Zeller is abundant in the Mediterranean countries. It attacks various dry fruit in cultures or in stored products, notably pomegranate, Punica granatum L.; date palm, Phoenis dactylifera L. plantations; citrus, Citrus spp., apricot, Prunus armeniaca L. and pistachios, Pistachio vera. We can find E. ceratoniae in the north as well as in the south of Tunisia, especially in central zones and Saharan areas where caterpillar infestations can reach 90% of pomegranate fruit and 20% of dates (Dhouibi 1991). To reduce this damage, several control methods have been experimented. Chemical control is the most effective means of control against pests. However, against this species, insecticides seem to be difficult and randomly used, due to the endophytic behaviour of the pyralid and the position of the fruit on the pomegranate tree. Moreover, this method has very ominous repercussions on biological cadence. Besides, it is necessary to look for other control means to allow the preservation of the ecosystem. In Tunisia, several efforts have been directed at biological control, by using local parasitoids and through usage of the bio-insecticides mainly Bacillus thuringiensis (Dhouibi 1992, 1994, Dhouibi and Jemmasi 1993). In order to substitute the chemical control and to strengthen the integrated control, other possibilities can be envisaged, for example, the genetic method or the autocidal control, that is, based on mass rearing and the substerile male releases into the natural population. For the purpose, it provokes the sterility to ulterior generations and evaluates the impact of irradiation on the different biological parameters of emerged adults from treated nymphs and their competitiveness. Dhouibi and Omran (1995) and Dhouibi and Tijani (1996) have studied the mass rearing of the carob moth pyralid on an artificial diet and the effect of different irradiation doses, especially a substerilising dose, on E. ceratoniae pupae

  15. Biological control against the carob moth Ectomyelois ceratoniae in oases and in packing houses in Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Dhouibi, M H; Cheikh, T; Cherni, M; Ben Moussa, I [Institut National Agronomique de Tunisie, Tunis Mahrajene (Tunisia); Hawlitsky, N [INRA Versaille (France); Zaaraoui, H; Krisaane, T [Groupement Interprofessionnel de Dattes de Toseur (Tunisia)

    2000-07-01

    The carob moth, Ectomyelois ceratoniae Zeller is abundant in the Mediterranean countries. It attacks various dry fruit in cultures or in stored products, notably pomegranate, Punica granatum L.; date palm, Phoenis dactylifera L. plantations; citrus, Citrus spp., apricot, Prunus armeniaca L. and pistachios, Pistachio vera. We can find E. ceratoniae in the north as well as in the south of Tunisia, especially in central zones and Saharan areas where caterpillar infestations can reach 90% of pomegranate fruit and 20% of dates (Dhouibi 1991). To reduce this damage, several control methods have been experimented. Chemical control is the most effective means of control against pests. However, against this species, insecticides seem to be difficult and randomly used, due to the endophytic behaviour of the pyralid and the position of the fruit on the pomegranate tree. Moreover, this method has very ominous repercussions on biological cadence. Besides, it is necessary to look for other control means to allow the preservation of the ecosystem. In Tunisia, several efforts have been directed at biological control, by using local parasitoids and through usage of the bio-insecticides mainly Bacillus thuringiensis (Dhouibi 1992, 1994, Dhouibi and Jemmasi 1993). In order to substitute the chemical control and to strengthen the integrated control, other possibilities can be envisaged, for example, the genetic method or the autocidal control, that is, based on mass rearing and the substerile male releases into the natural population. For the purpose, it provokes the sterility to ulterior generations and evaluates the impact of irradiation on the different biological parameters of emerged adults from treated nymphs and their competitiveness. Dhouibi and Omran (1995) and Dhouibi and Tijani (1996) have studied the mass rearing of the carob moth pyralid on an artificial diet and the effect of different irradiation doses, especially a substerilising dose, on E. ceratoniae pupae.

  16. Enhancing water stress tolerance improves fitness in biological control strains of Lactobacillus plantarum in plant environments.

    Science.gov (United States)

    Daranas, Núria; Badosa, Esther; Francés, Jesús; Montesinos, Emilio; Bonaterra, Anna

    2018-01-01

    Lactobacillus plantarum strains PM411 and TC92 can efficiently control bacterial plant diseases, but their fitness on the plant surface is limited under unfavourable low relative humidity (RH) conditions. To increase tolerance of these strains to water stress, an adaptive strategy was used consisting of hyperosmotic and acidic conditions during growth. Adapted cells had higher survival rates under desiccation than non-adapted cells. Transcript levels and patterns of general stress-related genes increased immediately after the combined-stress adaptation treatment, and remained unaltered or repressed during the desiccation challenge. However, there were differences between strains in the transcription patterns that were in agreement with a better performance of adapted cells of PM411 than TC92 in plant surfaces under low RH environmental conditions. The combined-stress adaptation treatment increased the survival of PM411 cells consistently in different plant hosts in the greenhouse and under field conditions. Stress-adapted cells of PM411 had similar biocontrol potential against bacterial plant pathogens than non-adapted cells, but with less variability within experiments.

  17. Enhancing water stress tolerance improves fitness in biological control strains of Lactobacillus plantarum in plant environments.

    Directory of Open Access Journals (Sweden)

    Núria Daranas

    Full Text Available Lactobacillus plantarum strains PM411 and TC92 can efficiently control bacterial plant diseases, but their fitness on the plant surface is limited under unfavourable low relative humidity (RH conditions. To increase tolerance of these strains to water stress, an adaptive strategy was used consisting of hyperosmotic and acidic conditions during growth. Adapted cells had higher survival rates under desiccation than non-adapted cells. Transcript levels and patterns of general stress-related genes increased immediately after the combined-stress adaptation treatment, and remained unaltered or repressed during the desiccation challenge. However, there were differences between strains in the transcription patterns that were in agreement with a better performance of adapted cells of PM411 than TC92 in plant surfaces under low RH environmental conditions. The combined-stress adaptation treatment increased the survival of PM411 cells consistently in different plant hosts in the greenhouse and under field conditions. Stress-adapted cells of PM411 had similar biocontrol potential against bacterial plant pathogens than non-adapted cells, but with less variability within experiments.

  18. Artificially constructed quorum-sensing circuits are used for subtle control of bacterial population density.

    Directory of Open Access Journals (Sweden)

    Zhaoshou Wang

    Full Text Available Vibrio fischeri is a typical quorum-sensing bacterium for which lux box, luxR, and luxI have been identified as the key elements involved in quorum sensing. To decode the quorum-sensing mechanism, an artificially constructed cell-cell communication system has been built. In brief, the system expresses several programmed cell-death BioBricks and quorum-sensing genes driven by the promoters lux pR and PlacO-1 in Escherichia coli cells. Their transformation and expression was confirmed by gel electrophoresis and sequencing. To evaluate its performance, viable cell numbers at various time periods were investigated. Our results showed that bacteria expressing killer proteins corresponding to ribosome binding site efficiency of 0.07, 0.3, 0.6, or 1.0 successfully sensed each other in a population-dependent manner and communicated with each other to subtly control their population density. This was also validated using a proposed simple mathematical model.

  19. A peptide export-import control circuit modulating bacterial development regulates protein phosphatases of the phosphorelay.

    Science.gov (United States)

    Perego, M

    1997-08-05

    The phosphorelay signal transduction system activates developmental transcription in sporulation of Bacillus subtilis by phosphorylation of aspartyl residues of the Spo0F and Spo0A response regulators. The phosphorylation level of these response regulators is determined by the opposing activities of protein kinases and protein aspartate phosphatases that interpret positive and negative signals for development in a signal integration circuit. The RapA protein aspartate phosphatase of the phosphorelay is regulated by a peptide that directly inhibits its activity. This peptide is proteolytically processed from an inactive pre-inhibitor protein encoded in the phrA gene. The pre-inhibitor is cleaved by the protein export apparatus to a putative pro-inhibitor that is further processed to the active inhibitor peptide and internalized by the oligopeptide permease. This export-import circuit is postulated to be a mechanism for timing phosphatase activity where the processing enzymes regulate the rate of formation of the active inhibitor. The processing events may, in turn, be controlled by a regulatory hierarchy. Chromosome sequencing has revealed several other phosphatase-prepeptide gene pairs in B. subtilis, suggesting that the use of this mechanism may be widespread in signal transduction.

  20. Biological control agents for suppression of post-harvest diseases of potatoes: strategies on discovery and development

    Science.gov (United States)

    As used in plant pathology, the term "biological control" or its short form “biocontrol” commonly refers to the decrease in the inoculum or the disease-producing activity of a pathogen accomplished through one or more organisms, including the host plant but excluding man. Biological control of plant...

  1. The influence of flower morphology and nectar quality on the longevity of a parasitoid biological control agent

    NARCIS (Netherlands)

    Vattala, H.D.; Wratten, S.D.; Phillips, C.B.; Wäckers, F.L.

    2006-01-01

    Conservation biological control aims to enhance the efficacy of arthropod biological control agents, such as parasitoids, partly by providing them with access to floral nectar. However, the suitability of a flower species for providing nectar to a parasitoid is dependent on the morphologies of the

  2. Protein-polymer nano-machines. Towards synthetic control of biological processes

    Directory of Open Access Journals (Sweden)

    Alexander Cameron

    2004-09-01

    Full Text Available Abstract The exploitation of nature's machinery at length scales below the dimensions of a cell is an exciting challenge for biologists, chemists and physicists, while advances in our understanding of these biological motifs are now providing an opportunity to develop real single molecule devices for technological applications. Single molecule studies are already well advanced and biological molecular motors are being used to guide the design of nano-scale machines. However, controlling the specific functions of these devices in biological systems under changing conditions is difficult. In this review we describe the principles underlying the development of a molecular motor with numerous potential applications in nanotechnology and the use of specific synthetic polymers as prototypic molecular switches for control of the motor function. The molecular motor is a derivative of a TypeI Restriction-Modification (R-M enzyme and the synthetic polymer is drawn from the class of materials that exhibit a temperature-dependent phase transition. The potential exploitation of single molecules as functional devices has been heralded as the dawn of new era in biotechnology and medicine. It is not surprising, therefore, that the efforts of numerous multidisciplinary teams 12. have been focused in attempts to develop these systems. as machines capable of functioning at the low sub-micron and nanometre length-scales 3. However, one of the obstacles for the practical application of single molecule devices is the lack of functional control methods in biological media, under changing conditions. In this review we describe the conceptual basis for a molecular motor (a derivative of a TypeI Restriction-Modification enzyme with numerous potential applications in nanotechnology and the use of specific synthetic polymers as prototypic molecular switches for controlling the motor function 4.

  3. Agronomic aspects of strip intercropping lettuce with alyssum for biological control of aphids

    OpenAIRE

    Brennan, Eric B.

    2013-01-01

    Organic lettuce growers in California typically use insectary strips of alyssum (Lobularia maritima (L.) Desv.) to attract hoverflies (Syrphidae) that provide biological control of aphids. A two year study with transplanted organic romaine lettuce in Salinas, California investigated agronomic aspects of lettuce monoculture and lettuce-alyssum strip intercropping on beds in replacement intercropping treatments where alyssum transplants replaced 2 to 8% of the lettuce transplants, and in additi...

  4. The Use and Exchange of Biological Control Agents for Food and Agriculture

    Institute of Scientific and Technical Information of China (English)

    J.C.van; Lenteren; M.J.W.Cock; J.Brodeur; B.Barratt; F.Bigler; K.Bolckmans; F.Haas; P.G.Mason; J.R.P.Parra

    2010-01-01

    The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories of biological control:classical and augmentative.Allowing access to BCAs for use inanother country imposes no risk of liability to the source country.Local scientific knowledge abouthabitats,fauna andflora,can be helpful

  5. Dynamic Analysis of a Phytoplankton-Fish Model with Biological and Artificial Control

    OpenAIRE

    Wang, Yapei; Zhao, Min; Pan, Xinhong; Dai, Chuanjun

    2014-01-01

    We investigate a nonlinear model of the interaction between phytoplankton and fish, which uses a pair of semicontinuous systems with biological and artificial control. First, the existence of an order-1 periodic solution to the system is analyzed using a Poincaré map and a geometric method. The stability conditions of the order-1 periodic solution are obtained by a theoretical mathematical analysis. Furthermore, based on previous analysis, we investigate the bifurcation in the order-1 periodi...

  6. Trichoderma-plant-pathogen interactions: advances in genetics of biological control.

    Science.gov (United States)

    Mukherjee, Mala; Mukherjee, Prasun K; Horwitz, Benjamin A; Zachow, Christin; Berg, Gabriele; Zeilinger, Susanne

    2012-12-01

    Trichoderma spp. are widely used in agriculture as biofungicides. Induction of plant defense and mycoparasitism (killing of one fungus by another) are considered to be the most important mechanisms of Trichoderma-mediated biological control. Understanding these mechanisms at the molecular level would help in developing strains with superior biocontrol properties. In this article, we review our current understanding of the genetics of interactions of Trichoderma with plants and plant pathogens.

  7. A blinded, randomized controlled trial of high-dose vitamin D supplementation to reduce recurrence of bacterial vaginosis.

    Science.gov (United States)

    Turner, Abigail Norris; Carr Reese, Patricia; Fields, Karen S; Anderson, Julie; Ervin, Melissa; Davis, John A; Fichorova, Raina N; Roberts, Mysheika Williams; Klebanoff, Mark A; Jackson, Rebecca D

    2014-11-01

    Low serum vitamin D levels have been associated with increased prevalence of the reproductive tract condition bacterial vaginosis (BV). The objective of this trial was to evaluate the effect of high-dose vitamin D supplementation on BV recurrence. This randomized, placebo-controlled, double-blinded trial enrolled 118 women with symptomatic BV from an urban sexually transmitted disease clinic (clinicaltrials.gov registration NCT01450462). All participants received 500 mg of oral metronidazole twice daily for 7 days. Intervention participants (n = 59) also received 9 doses of 50,000 IU of cholecalciferol (vitamin D3) over 24 weeks; control women (n = 59) received matching placebo. Recurrent BV was assessed via Nugent scoring after 4, 12, and 24 weeks. We assessed the effect of the intervention using an intention-to-treat approach, fitting Cox proportional hazards models to evaluate recurrent BV over the follow-up period. Most participants (74%) were black, with a median age of 26 years. Median presupplementation serum 25-hydroxyvitamin D [25(OH)D] was similar across randomization arms: 16.6 ng/mL in the vitamin D arm and 15.8 ng/mL in the control arm. At trial completion, median 25(OH)D among women receiving vitamin D was 30.5 ng/mL, vs 17.8 ng/mL in control women; 16% of women receiving vitamin D and 57% receiving placebo remained vitamin D deficient (<20 ng/mL). BV prevalence among women randomized to vitamin D was very similar to those randomized to placebo at the 4- and 12-week visits, but by the 24-week visit, BV prevalence was 65% among women in the vitamin D arm and 48% among control women. BV recurrence was not reduced by vitamin D supplementation (intention-to-treat hazard ratio, 1.11; 95% confidence interval, 0.68-1.81). Among women experiencing recurrent BV, median time to recurrence was 13.7 weeks in the vitamin D arm and 14.3 weeks in the control arm. Women receiving vitamin D experienced significant increases in serum 25(OH)D, but this increase was not

  8. Cellular adverse actions of dibromoacetonitrile, a by-product in water bacterial control, at sublethal levels in rat thymocytes.

    Science.gov (United States)

    Kishida, Takumi; Akiyoshi, Kenji; Erdenedalai, Erdenebat; Enhetomuru, Anu; Imai, Shoji; Oyama, Yasuo

    2018-09-01

    The aim of this study was to investigate the effects of dibromoacetonitrile (DBAN), a by-product in water bacterial control, at sublethal concentrations on rat thymocytes, by using a cytometric technique with appropriate fluorescent dyes. By using this method, the possibility that DBAN induces cellular actions related to oxidative stress was assessed. DBAN reduced the content of cellular nonprotein thiols under Zn 2+ -free conditions. It elevated the intracellular level of Zn 2+ , being independent from external Zn 2+ . DBAN increased cell vulnerability to the cytotoxic action of hydrogen peroxide. These actions of DBAN were likely related to oxidative stress. DBAN is formed by the reaction of bromides and chlorinated oxidants during water disinfection. Hydrolysis of 2,2-dibromo-3-nitrilopropionamide, an antimicrobial used in hydraulic fracturing fluids for production of shale gas and oil, produces DBAN. Therefore, the concern regarding the levels of DBAN in industrial water systems is necessary to avoid the environmental risk to humans and wild mammals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Efficacy and safety of oral tinidazole and metronidazole in treatment of bacterial vaginosis: a randomized control trial

    Directory of Open Access Journals (Sweden)

    Zahra Abbaspoor

    2014-05-01

    Full Text Available Aims: Oral metronidazole 500 mg twice a day for one week is currently the treatment of choice for bacterial vaginosis (BV. Complete treatment by this regimen takes time and occurs less often. This drug has significant side effects too. Using a drug in the shortest treatment course may increases the success of treatment. To evaluate the effectiveness and safety of oral tinidazole compare to metronidazole in treatment of BV.Methods: In this randomized, controlled, double-blind, comparative, clinical trial, 110 non-pregnant women aged between 15-45 years with confirmed diagnosis of BV by Amsels criteria were randomly assigned to receive either 2 g tinidazole tablet once daily for 2 days (n=55 or 500 mg metronidazole table twice daily for 7 days (n=55.The cure and recurrence rate were evaluated in both groups after 2 and 4 weeks follow up visits. For statistical analysis t-test,   test, fisher's exact test and Mann-Whitney test were used.Results: The results showed that cure rate after 2 weeks in tinidazole tablet group was 84.6٪ and in metronidazole group was 85.4٪ (p=0.9, and after 4 weeks recurrence rate in tinidazole and metronidazole groups was 6.9٪and 12.1٪respectively (P=0.3.Conclusions: Tinidazole table 2 g once daily for 2 days is as effective as metronidazole tablet 500 mg twice a day for 7 days in treatment of BV.

  10. Supercritical CO2 impregnation of PLA/PCL films with natural substances for bacterial growth control in food packaging.

    Science.gov (United States)

    Milovanovic, Stoja; Hollermann, Gesa; Errenst, Cornelia; Pajnik, Jelena; Frerich, Sulamith; Kroll, Stephen; Rezwan, Kurosch; Ivanovic, Jasna

    2018-05-01

    Biodegradable polymers with antibacterial properties are highly desirable materials for active food packaging applications. Thymol, a dietary monoterpene phenol with a strong antibacterial activity is abundant in plants belonging to the genus Thymus. This study presents two approaches for supercritical CO 2 impregnation of poly(lactic acid)(PLA)/poly(ε-caprolactone)(PCL) blended films to induce antibacterial properties of the material: (i) a batch impregnation process for loading pure thymol, and (ii) an integrated supercritical extraction-impregnation process for isolation of thyme extract and its incorporation into the films, operated in both batch or semi-continuous modes with supercritical solution circulation. The PCL content in films, impregnation time and CO 2 flow regime were varied to maximize loading of the films with thymol or thyme extract with preserving films' structure and thermal stability. Representative film samples impregnated with thymol and thyme extract were tested against Gram (-) (Escherichia coli) and Gram(+) (Bacillus subtilis) model strains, by measuring their metabolic activity and re-cultivation after exposure to the films. The film containing thymol (35.8 wt%) showed a strong antibacterial activity leading to a total reduction of bacterial cell viability. Proposed processes enable fast, controlled and organic solvent-free fabrication of the PLA/PCL films containing natural antibacterial substances at moderately low temperature, with a compact structure and a good thermal stability, for potential use as active food packaging materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Evaluation of biologic occupational risk control practices: quality indicators development and validation.

    Science.gov (United States)

    Takahashi, Renata Ferreira; Gryschek, Anna Luíza F P L; Izumi Nichiata, Lúcia Yasuko; Lacerda, Rúbia Aparecida; Ciosak, Suely Itsuko; Gir, Elucir; Padoveze, Maria Clara

    2010-05-01

    There is growing demand for the adoption of qualification systems for health care practices. This study is aimed at describing the development and validation of indicators for evaluation of biologic occupational risk control programs. The study involved 3 stages: (1) setting up a research team, (2) development of indicators, and (3) validation of the indicators by a team of specialists recruited to validate each attribute of the developed indicators. The content validation method was used for the validation, and a psychometric scale was developed for the specialists' assessment. A consensus technique was used, and every attribute that obtained a Content Validity Index of at least 0.75 was approved. Eight indicators were developed for the evaluation of the biologic occupational risk prevention program, with emphasis on accidents caused by sharp instruments and occupational tuberculosis prevention. The indicators included evaluation of the structure, process, and results at the prevention and biologic risk control levels. The majority of indicators achieved a favorable consensus regarding all validated attributes. The developed indicators were considered validated, and the method used for construction and validation proved to be effective. Copyright (c) 2010 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  12. Towards Biological Control of Kudzu Through an Improved Understanding of Insect-Kudzu Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Orr, D.; Barber, G.; DeBarr, G.; Thornton, M.

    2001-08-03

    The authors evaluated various approaches to the biological control of kudzu and exotic weed that infests the SRS. A large number of native pollinators were found to be attracted to kudzu. The viability of seed was found to be low, between 2% and 11%. This is the result of native Hemiptera. The results suggest that seed feeding insects should not be targeted for importation. Both kudzu and soybeans had the same level of abundance and diversity of herbivore insects and the same levels of defoliation. No vine or root damaging species were found. Efforts should be targeted to the latter insects to control kudzu.

  13. Quality control in the neutron activation analysis of biological markers for selenium in epidemiological investigations

    International Nuclear Information System (INIS)

    Morris, J.S.; Ngwenyama, R.A.; Guthrie, J.M.; Brockman, J.D.; Spate, V.L.; Robertson, J.D.

    2008-01-01

    Instrumental neutron activation analysis is routinely used at the MURR to quantify selenium in prospectively-collected biologic markers including blood serum and toenails. These specimens are typically collected from well-defined cohort populations participating in investigations assessing selenium intake and incidence of chronic disease endpoints. These epidemiological investigations, whether observational (case-control) or clinical (intervention), typically generate thousands of samples. The purpose of this paper is to assess, through evaluation of quality control results, if the achievable accuracy and precision in the measurement of selenium using NAA is adequate to determine a relative risk of 1.2 at high confidence in epidemiological studies. (author)

  14. Is the efficacy of biological control against plant diseases likely to be more durable than that of chemical pesticides?

    Directory of Open Access Journals (Sweden)

    Marc eBardin

    2015-07-01

    Full Text Available The durability of a control method for plant protection is defined as the persistence of its efficacy in space and time. It depends on (i the selection pressure exerted by it on populations of plant pathogens and (ii on the capacity of these pathogens to adapt to the control method. Erosion of effectiveness of conventional plant protection methods has been widely studied in the past. For example, apparition of resistance to chemical pesticides in plant pathogens or pests has been extensively documented. The durability of biological control has often been assumed to be higher than that of chemical control. Results concerning pest management in agricultural systems have shown that this assumption may not always be justified. Resistance of various pests to one or several toxins of Bacillus thuringensis and apparition of resistance of the codling moth Cydia pomonella to the Cydia pomonella granulovirus have, for example, been described. In contrast with the situation for pests, the durability of biological control of plant diseases has hardly been studied and no scientific reports proving the loss of efficiency of biological control agents against plant pathogens in practice has been published so far. Knowledge concerning the possible erosion of effectiveness of biological control is essential to ensure a durable efficacy of biological control agents on target plant pathogens. This knowledge will result in identifying risk factors that can foster the selection of strains of plant pathogens resistant to biological control agents. It will also result in identifying types of biological control agents with lower risk of efficacy loss i.e. modes of action of biological control agents that does not favor the selection of resistant isolates in natural populations of plant pathogens. An analysis of the scientific literature was then conducted to assess the potential for plant pathogens to become resistant to biological control agents.

  15. Integration of Plant Defense Traits with Biological Control of Arthropod Pests: Challenges and Opportunities.

    Science.gov (United States)

    Peterson, Julie A; Ode, Paul J; Oliveira-Hofman, Camila; Harwood, James D

    2016-01-01

    Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be semiochemically, plant toxin-, plant nutrient-, and/or physically mediated. Case studies involving predators, parasitoids, and pathogens of crop pests will be presented and discussed. These diverse groups of natural enemies may respond differently to crop plant traits based on their own unique biology and the ecological niches they fill. Genetically modified crop plants that have been engineered to express transgenic products affecting herbivorous pests are an additional consideration. For the most part, transgenic plant incorporated protectant (PIP) traits are compatible with biological control due to their selective toxicity to targeted pests and relatively low non-target impacts, although transgenic crops may have indirect effects on higher trophic levels and arthropod communities mediated by lower host or prey number and/or quality. Host plant resistance and biological control are two of the key pillars of integrated pest management; their potential interactions, whether they are synergistic, complementary, or disruptive, are key in understanding and achieving sustainable and effective pest management.

  16. Integration of plant defense traits with biological control of arthropod pests: challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Julie A Peterson

    2016-11-01

    Full Text Available Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be semiochemically-, plant toxin-, plant nutrient-, and/or physically-mediated. Case studies involving predators, parasitoids, and pathogens of crop pests will be presented and discussed. These diverse groups of natural enemies may respond differently to crop plant traits based on their own unique biology and the ecological niches they fill. Genetically modified crop plants that have been engineered to express transgenic products affecting herbivorous pests are an additional consideration. For the most part, transgenic plant incorporated protectant (PIP traits are compatible with biological control due to their selective toxicity to targeted pests and relatively low non-target impacts, although transgenic crops may have indirect effects on higher trophic levels and arthropod communities mediated by lower host or prey number and/or quality. Host plant resistance and biological control are two of the key pillars of integrated pest management; their potential interactions, whether they are synergistic, complementary, or disruptive, are key in understanding and achieving sustainable and effective pest management.

  17. Evaluation of an Internally Controlled Multiplex Tth Endonuclease Cleavage Loop-Mediated Isothermal Amplification (TEC-LAMP Assay for the Detection of Bacterial Meningitis Pathogens

    Directory of Open Access Journals (Sweden)

    Owen Higgins

    2018-02-01

    Full Text Available Bacterial meningitis infection is a leading global health concern for which rapid and accurate diagnosis is essential to reduce associated morbidity and mortality. Loop-mediated isothermal amplification (LAMP offers an effective low-cost diagnostic approach; however, multiplex LAMP is difficult to achieve, limiting its application. We have developed novel real-time multiplex LAMP technology, TEC-LAMP, using Tth endonuclease IV and a unique LAMP primer/probe. This study evaluates the analytical specificity, limit of detection (LOD and clinical application of an internally controlled multiplex TEC-LAMP assay for detection of leading bacterial meningitis pathogens: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae. Analytical specificities were established by testing 168 bacterial strains, and LODs were determined using Probit analysis. The TEC-LAMP assay was 100% specific, with LODs for S. pneumoniae, N. meningitidis and H. influenzae of 39.5, 17.3 and 25.9 genome copies per reaction, respectively. Clinical performance was evaluated by testing 65 archived PCR-positive samples. Compared to singleplex real-time PCR, the multiplex TEC-LAMP assay demonstrated diagnostic sensitivity and specificity of 92.3% and 100%, respectively. This is the first report of a single-tube internally controlled multiplex LAMP assay for bacterial meningitis pathogen detection, and the first report of Tth endonuclease IV incorporation into nucleic acid amplification diagnostic technology.

  18. Evaluation of an Internally Controlled Multiplex Tth Endonuclease Cleavage Loop-Mediated Isothermal Amplification (TEC-LAMP) Assay for the Detection of Bacterial Meningitis Pathogens

    Science.gov (United States)

    Clancy, Eoin; Cormican, Martin; Boo, Teck Wee; Cunney, Robert

    2018-01-01

    Bacterial meningitis infection is a leading global health concern for which rapid and accurate diagnosis is essential to reduce associated morbidity and mortality. Loop-mediated isothermal amplification (LAMP) offers an effective low-cost diagnostic approach; however, multiplex LAMP is difficult to achieve, limiting its application. We have developed novel real-time multiplex LAMP technology, TEC-LAMP, using Tth endonuclease IV and a unique LAMP primer/probe. This study evaluates the analytical specificity, limit of detection (LOD) and clinical application of an internally controlled multiplex TEC-LAMP assay for detection of leading bacterial meningitis pathogens: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae. Analytical specificities were established by testing 168 bacterial strains, and LODs were determined using Probit analysis. The TEC-LAMP assay was 100% specific, with LODs for S. pneumoniae, N. meningitidis and H. influenzae of 39.5, 17.3 and 25.9 genome copies per reaction, respectively. Clinical performance was evaluated by testing 65 archived PCR-positive samples. Compared to singleplex real-time PCR, the multiplex TEC-LAMP assay demonstrated diagnostic sensitivity and specificity of 92.3% and 100%, respectively. This is the first report of a single-tube internally controlled multiplex LAMP assay for bacterial meningitis pathogen detection, and the first report of Tth endonuclease IV incorporation into nucleic acid amplification diagnostic technology. PMID:29425124

  19. The Florey lecture, 1983. Biological control, as exemplified by smallpox eradication and myxomatosis.

    Science.gov (United States)

    Fenner, F

    1983-06-22

    Biological control is an important method of dealing with plant and insect pests. The control of rabbits by myxomatosis and the eradication of smallpox by vaccination are unusual examples of biological control, in that they involve a vertebrate and a viral pest respectively. Myxomatosis is a benign disease in Sylvilagus rabbits in South America which is transmitted mechanically by mosquitoes. In the European rabbit, Oryctolagus, which is a pest in Australia and England, the virus from Sylvilagus produces a generalized disease that is almost always lethal. Myxomatosis was deliberately introduced into Australia in 1950 and into Europe in 1952. It was at first spectacularly successful in controlling the rabbit pest, but biological adjustments occurred in the virulence of the virus and the genetic resistances of rabbits. After 30 years of interaction, natural selection has resulted in a balance at a fairly high level of viral virulence. Smallpox has been a major scourge of mankind for over 1500 years. It spread from Asia to Europe in the Middle ages and from Europe to Africa and the Americas in the 15th and 16th centuries. Jenner's cowpox vaccine provided a method of control that reduced the severity of the disease during the 19th century but failed to eliminate the disease from many countries before the 1930s. Thereafter it was eradicated from Europe and North America, but remained endemic in South America, Africa and Asia. In 1967 it was still endemic in 33 countries and W.H.O. established a programme for global eradication within 10 years. The goal was achieved in 1977. Problems of the eradication programme and reasons for its success will be described.

  20. Biological control of white mold by Trichoderma harzianum in common bean under field conditions

    Directory of Open Access Journals (Sweden)

    Daniel Diego Costa Carvalho

    2015-12-01

    Full Text Available Abstract: The objective of this work was to evaluate Trichoderma harzianum isolates for biological control of white mold in common bean (Phaseolus vulgaris. Five isolates were evaluated for biocontrol of white mold in 'Perola' common bean under field conditions, in the 2009 and 2010 crop seasons. A commercial isolate (1306 and a control treatment were included. Foliar applications at 2x109 conidia mL-1 were performed at 42 and 52 days after sowing (DAS, in 2009, and at 52 DAS in 2010. The CEN287, CEN316, and 1306 isolates decreased the number of Sclerotinia sclerotiorum apothecia per square meter in comparison to the control, in both crop seasons. CEN287, CEN316, and 1306 decreased white mold severity during the experimental period, when compared to the control.