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Sample records for postharvest pathogen inoculum

  1. Biological control of postharvest pathogens

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    Postharvest diseases of harvested commodities cause significant reductions in food availability and financial profits. Additionally, regulatory agencies are increasingly restricting or banning the postharvest use of synthetic chemical fungicides. This has increased the need to develop more ecofrie...

  2. Susceptibility of Postharvest Pathogens to Esential Oils

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    Božik M.

    2017-09-01

    Full Text Available Antimicrobial volatile substances from plants represent alternatives to synthetic pesticides and food preservatives. In this study, the compositions of some essential oils were determined by gas chromatography with mass spectrometry, and the inhibitory properties of the essential oils and their components against the bacterial postharvest pathogens Pectobacterium carotovorum subsp. carotovorum (CCM 1008, Pseudomonas syringae (CCM 7018, Xanthomonas campestris (CCM 22 were determined by the microdilution method. Essential oils from oregano, cinnamon, lemongrass, lavender, clove, rosemary, tea tree, eucalyptus, garlic, and ginger and their components cinnamaldehyde, eugenol, thymol, and carvacrol were used in the tests. The essential oil components exhibited strong antibacterial activity against all tested bacteria. The oregano and cinnamon essential oils were most effective. The rosemary, lavender, tea tree, eucalyptus, garlic, and ginger oils were not effective at the tested concentrations. In conclusion, certain essential oils, particularly their components, are highly effective and could be used for the control of postharvest bacterial pathogens.

  3. An antifungal role of hydrogen sulfide on the postharvest pathogens Aspergillus niger and Penicillium italicum.

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    Liu-Hui Fu

    Full Text Available In this research, the antifungal role of hydrogen sulfide (H2S on the postharvest pathogens Aspergillus niger and Penicillium italicum growing on fruits and under culture conditions on defined media was investigated. Our results show that H2S, released by sodium hydrosulfide (NaHS effectively reduced the postharvest decay of fruits induced by A. niger and P. italicum. Furthermore, H2S inhibited spore germination, germ tube elongation, mycelial growth, and produced abnormal mycelial contractions when the fungi were grown on defined media in Petri plates. Further studies showed that H2S could cause an increase in intracellular reactive oxygen species (ROS in A. niger. In accordance with this observation we show that enzyme activities and the expression of superoxide dismutase (SOD and catalase (CAT genes in A. niger treated with H2S were lower than those in control. Moreover, H2S also significantly inhibited the growth of Saccharomyces cerevisiae, Rhizopus oryzae, the human pathogen Candida albicans, and several food-borne bacteria. We also found that short time exposure of H2S showed a microbicidal role rather than just inhibiting the growth of microbes. Taken together, this study suggests the potential value of H2S in reducing postharvest loss and food spoilage caused by microbe propagation.

  4. Utilization of biological control agents for the management of postharvest pathogens of tomato

    International Nuclear Information System (INIS)

    Zafar, M.U.; Ansari, S.U.

    2016-01-01

    Twenty five isolates of Trichoderma, Bacillus and Pseudomonas spp. were obtained from rhizosphere of tomato growing fields using soil dilution technique on potato dextrose agar (PDA) and nutrient agar (NA) medium. Screening of these isolates were done against Geotrichum candidum, Trichothecium roseum and Rhizopus oryzae, causal agents of sour rot, pink mold rot and Rhizopus soft rot of tomato under the laboratory conditions. One promising isolate of each Trichoderma harzianum, Bacillus spp. and Pseudomonas fluorescens from the twenty five isolates were chosen and further evaluated as potential biological control agents (BCAs) against three important postharvest pathogens of tomato. Dual culture and spore concentration assay revealed that all three isolates inhibited radial growth of G. candidum, T. roseum and R. oryzae. Tomato fruits were inoculated with 25 micro L suspension of 10/sup 8/ cfu mL-1 for T. harzianum and 10/sup 8/cfu mL-1for each Bacillus sp. and P. fluorescens. Twenty four hours later the treated fruits were inoculated with 25 micro L of 105 conidia/mL of each of three postharvest pathogens. The results showed that P. fluorescens provided good control (78.1%) of G. candidum and (82.2%) R. oryzae, while, T. harzianum proved less effective to control all three pathogens. Bacillus spp. was only effective (88.4%) against T. roseum. Hence, our results depicted that Bacillus spp. and P. fluorescens proved to be a potential antagonist of T. roseum and R. oryzae however, all the tested BCAs were not consistent in their action against three postharvest pathogens of tomato. (author)

  5. Resting spore formation of aphid-pathogenic fungus Pandora nouryi depends on the concentration of infective inoculum.

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    Huang, Zhi-Hong; Feng, Ming-Guang

    2008-07-01

    Resting spore formation of some aphid-pathogenic Entomophthorales is important for the seasonal pattern of their prevalence and survival but this process is poorly understood. To explore the possible mechanism involved in the process, Pandora nouryi (obligate aphid pathogen) interacted with green peach aphid Myzus persicae on cabbage leaves under favourable conditions. Host nymphs showered with primary conidia of an isolate (LC(50): 0.9-6.7 conidia mm(-2) 4-7 days post shower) from air captures in the low-latitude plateau of China produced resting spores (azygospores), primary conidia or both spore types. Surprisingly, the proportion of mycosed cadavers forming resting spores (P(CFRS)) increased sharply within the concentrations (C) of 28-240 conidia mm(-2), retained high levels at 240-1760, but was zero or extremely low at 0.3-16. The P(CFRS)-C relationship fit well the logistic equation P(CFRS) = 0.6774/[1 + exp(3.1229-0.0270C)] (r(2) = 0.975). This clarified for the first time the dependence of in vivo resting spore formation of P. nouryi upon the concentration of infective inoculum. A hypothesis is thus proposed that some sort of biochemical signals may exist in the host-pathogen interaction so that the fungal pathogen perceives the signals for prompt response to forthcoming host-density changes by either producing conidia for infecting available hosts or forming resting spores for surviving host absence in situ.

  6. Potential of Cerbera odollam as a bio-fungicide for post-harvest pathogen Penicilium digitatum

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    Singh, Harbant; Yin-Chu, Sue; Al-Samarrai, Ghassan; Syarhabil, Muhammad

    2015-05-01

    Postharvest diseases due to fungal infection contribute to economic losses in agriculture industry during storage, transportation or in the market. Penicillium digitatum is one of the common pathogen responsible for the postharvest rot in fruits. This disease is currently being controlled by synthetic fungicides such as Guazatine and Imazalil. However, heavy use of fungicides has resulted in environmental pollution, such as residue in fruit that expose a significant risk to human health. Therefore, there is a strong need to develop alternatives to synthetic fungicide to raise customer confidence. In the current research, different concentrations (500 to 3000 ppm) of ethanol extract of Cerbera odollam or commonly known as Pong-pong were compared with Neem and the controls (Positive control/Guazatine; Negative control/DMSO) for the anti-fungicide activity in PDA media contained in 10 cm diameter Petri dishes, using a modification of Ruch and Worf's method. The toxicity (Lc50) of the C.odollam extract was determined by Brine-shrimp test (BST). The results of the research indicated that crude extraction from C.odollam showed the highest inhibition rate (93%) and smallest colony diameter (0.63 cm) at 3000 ppm in vitro compared with Neem (inhibition rate: 88%; colony diameter: 1.33 cm) and control (Positive control/Guazatine inhibition rate: 79%, colony diameter: 1.9 cm; Negative control/DMSO inhibition rate: 0%, colony diameter: 9.2 cm). C.odollam recorded Lc50 value of 5 µg/ml which is safe but to be used with caution (unsafe level: below 2 µg/ml). The above anti-microbial activity and toxicity value results indicate that C.odollam has a potential of being a future bio-fungicide that could be employed as an alternative to synthetic fungicide.

  7. A Mathematical Model for Pathogen Cross-Contamination Dynamics during the Postharvest Processing of Leafy Greens.

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    Mokhtari, Amir; Oryang, David; Chen, Yuhuan; Pouillot, Regis; Van Doren, Jane

    2018-01-08

    We developed a probabilistic mathematical model for the postharvest processing of leafy greens focusing on Escherichia coli O157:H7 contamination of fresh-cut romaine lettuce as the case study. Our model can (i) support the investigation of cross-contamination scenarios, and (ii) evaluate and compare different risk mitigation options. We used an agent-based modeling framework to predict the pathogen prevalence and levels in bags of fresh-cut lettuce and quantify spread of E. coli O157:H7 from contaminated lettuce to surface areas of processing equipment. Using an unbalanced factorial design, we were able to propagate combinations of random values assigned to model inputs through different processing steps and ranked statistically significant inputs with respect to their impacts on selected model outputs. Results indicated that whether contamination originated on incoming lettuce heads or on the surface areas of processing equipment, pathogen prevalence among bags of fresh-cut lettuce and batches was most significantly impacted by the level of free chlorine in the flume tank and frequency of replacing the wash water inside the tank. Pathogen levels in bags of fresh-cut lettuce were most significantly influenced by the initial levels of contamination on incoming lettuce heads or surface areas of processing equipment. The influence of surface contamination on pathogen prevalence or levels in fresh-cut bags depended on the location of that surface relative to the flume tank. This study demonstrates that developing a flexible yet mathematically rigorous modeling tool, a "virtual laboratory," can provide valuable insights into the effectiveness of individual and combined risk mitigation options. © 2018 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

  8. Physical Interactions between Yeast Pichia guilliermondii and Post-Harvest Fruit Pathogen Penicillium expansum

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    SRI WIDYASTUTI

    2008-03-01

    Full Text Available Attachment of yeast cells or bacteria on fungal hyphae have been observed in various antagonisms between microorganisms. Physical interactions between yeast Pichia guilliermondii and postharvest fruit pathogen Penicillium expansum in culture were studied in detail using light and transmission electron microscope to give better understanding on their mode of antagonism. Both organisms were co-cultured for 24-hr on potato dextrose agar. Light microscopy observations on the co-culture showed that the yeast cells attached firmly on the fungal hyphae. This attachment was inhibited by several substances such as enzymes degrading protein (protease or trypsin, a respiration inhibitor (sodium azide, an acid (hydrochloric acid or an alkali (sodium hydroxide. Although autoclaved hyphae did not affect the attachment, but boiled enzymes and autoclaved yeast cells totally abolished the attachment. These evidences suggested that the attachment might be an active process mediated by certain protein from live yeast cells. Transmission electron micrographs on the ultrastructure of the co-culture revealed that the hyphae showed abnormalities in their structure and organelles, and a degree of obvious damage. Physical interactions observed in this study could be contributed to the mechanism of antagonism between P. guilliermondii and P. expansum.

  9. Effcacy of different biological control agents against major postharvest pathogens of grapes under room temperature storage conditions

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    Ramu SENTHIL

    2011-05-01

    Full Text Available Normal 0 14 false false false IT ZH-TW X-NONE MicrosoftInternetExplorer4 Grapes were treated post harvest with a variety of biological agents to determine their effcacy in reducing yield loss. The agents Pseudomonas, Bacillus, Trichoderma and yeast isolates were individually screened against a number of postharvest pathogens including Aspergillus carbonarius, Penicillum expansum, and Fusarium moniliforme. B. subtilis strains EPC-8 and EPCO-16 showed high mycelial growth suppression of A. carbonarius and P. expansum  in vitro. The fungal antagonist Trichoderma viride strain (Tv Tvm was the most effective, inhibiting mycelial growth by 88.8 per cent. The biological control agents were tested in pre, post and combined inoculation studies against postharvest pathogens of grapes.  In the pre inoculation, B. subtilis (EPC-8 reduced the disease incidence of A. carbonarius causing rot, T. harzianum (Th Co was effective against P. expansum, and T. viride (Tv Tvm was effective against F. moniliforme. The same trend of effectiveness was also found in the post-inoculation and combined inoculation tests.

  10. The citrus postharvest pathogen Penicillium digitatum depends on the PdMpkB kinase for developmental and virulence functions.

    Science.gov (United States)

    Ma, Haijie; Sun, Xuepeng; Wang, Mingshuang; Gai, Yunpeng; Chung, Kuang-Ren; Li, Hongye

    2016-11-07

    The postharvest pathogen Penicillium digitatum causes green mold decay on citrus fruit, resulting in severe economic losses. To explore possible factors involved in fungal pathogenesis, phenotypic characterization of the budding yeast Fus3/Kiss1 mitogen-activated protein (MAP) kinase homolog was carried out. The P. digitatum MAP kinase B coding gene, designated PdMpkB, was functionally inactivated via homologous recombination. The fungal strain (∆PdMpkB) carrying a PdMpkBdeletion demonstrated altered gene expression profiles, reduced growth and conidiogenesis, elevated resistance to osmotic stress, and failed to induce green mold decay on citrus fruit. ∆PdMpkB was more resistant to CaCl2, NaCl and sorbitol than its progenitor strain, indicating a negative regulatory function of PdMpkB in osmotic stress adaptation. Fungal infection assays on citrus fruit revealed that ∆PdMpkB proliferated poorly within host tissues, induced water-soaking lesions, failed to break through host cuticle layers and thus, failed to produce aerial hyphae and conidia. Introduction of a functional copy of PdMpkB into a null mutant restored all defective phenotypes. Transcriptome analysis revealed that inactivation of PdMpkB impacted expression of the genes associated with cell wall-degrading enzyme activities, carbohydrate and amino acid metabolisms, conidial formation, and numerous metabolic processes. Our results define pivotal roles of the PdMpkB-mediated signaling pathway in developmental and pathological functions in the citrus postharvest pathogen P. digitatum. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Ecological Networks in Stored Grain: Key Postharvest Nodes for Emerging Pests, Pathogens, and Mycotoxins.

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    Hernandez Nopsa, John F; Daglish, Gregory J; Hagstrum, David W; Leslie, John F; Phillips, Thomas W; Scoglio, Caterina; Thomas-Sharma, Sara; Walter, Gimme H; Garrett, Karen A

    2015-10-01

    Wheat is at peak quality soon after harvest. Subsequently, diverse biota use wheat as a resource in storage, including insects and mycotoxin-producing fungi. Transportation networks for stored grain are crucial to food security and provide a model system for an analysis of the population structure, evolution, and dispersal of biota in networks. We evaluated the structure of rail networks for grain transport in the United States and Eastern Australia to identify the shortest paths for the anthropogenic dispersal of pests and mycotoxins, as well as the major sources, sinks, and bridges for movement. We found important differences in the risk profile in these two countries and identified priority control points for sampling, detection, and management. An understanding of these key locations and roles within the network is a new type of basic research result in postharvest science and will provide insights for the integrated pest management of high-risk subpopulations, such as pesticide-resistant insect pests.

  12. Proteomic Analysis of Kiwifruit in Response to the Postharvest Pathogen, Botrytis cinerea

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    Jia Liu

    2018-02-01

    Full Text Available Gray mold, caused by the fungus Botrytis cinerea, is the most significant postharvest disease of kiwifruit. In the present study, iTRAQ with LC-ESI-MS/MS was used to identify the kiwifruit proteins associated with the response to B. cinerea. A total of 2,487 proteins in kiwifruit were identified. Among them, 292 represented differentially accumulated proteins (DAPs, with 196 DAPs having increased, and 96 DAPs having decreased in accumulation in B. cinerea-inoculated vs. water-inoculated, control kiwifruits. DAPs were associated with penetration site reorganization, cell wall degradation, MAPK cascades, ROS signaling, and PR proteins. In order to examine the corresponding transcriptional levels of the DAPs, RT-qPCR was conducted on a subset of 9 DAPs. In addition, virus-induced gene silencing was used to examine the role of myosin 10 in kiwifruit, a gene modulating host penetration resistance to fungal infection, in response to B. cinerea infection. The present study provides new insight on the understanding of the interaction between kiwifruit and B. cinerea.

  13. Antifungal Effects of Zataria multiflora Essential Oil on the Inhibitory Growth of some Postharvest Pathogenic Fungi

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    Mahboobeh NASSERI

    2015-12-01

    Full Text Available The present study aimed to determine minimum inhibitory concentration and minimum fungicidal concentration of the essential oil of Zataria multiflora to control Alternaria solani, Rhizoctonia solani, Rhizopus stolonifer, Aspergillus flavus, Aspergillus ochraceus and Aspergillus niger. The essential oil of Zataria multiflora was tested in vitro on PDA (malt extract agar medium with eight concentrations: 0, 10, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 ppm. This investigation followed the completely randomized design (CRD with three replications. GC-MS evaluations of the essential oil revealed that thymol (35%, carvacrol (34%, cymene-p (9.89%, gamma-terpinene (5.88% and alpha-pinene (4.22% were the main compounds of Zataria multiflora oil. The results showed that the essential oil of Zataria multiflora has antifungal activity; the lowest inhibition (75% was observed in the A. niger, while the highest inhibition (95.3% was observed in A. solani. Minimum inhibitory concentration for A. solani, R. solani, R. stolonifer, A. flavus, A. ochraceus and A. niger was 200, 200, 200, 300, 300 and 200 ppm respectively. In addition, the present results showed that minimum fungicidal concentration (MFC for A. solani, R. solani, R .stolonifer, A. niger and A.ochraceus was 600, 400, 300, 900 and 700 ppm respectively and none of the tested concentrations were fatal for A. flavus. A. solani and R. solani showed a strong sensitivity to Zataria multiflora essential oil at all concentrations. Findings of the current study suggest that essential oils of Zataria multiflora could be used for control of postharvest phytopathogenic fungi on fruits or vegetables.

  14. Activity of the pterophyllins 2 and 4 against postharvest fruit pathogenic fungi. Comparison with a synthetic analog and related intermediates.

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    Pergomet, Jorgelina L; Di Liberto, Melina G; Derita, Marcos G; Bracca, Andrea B J; Kaufman, Teodoro S

    2018-03-01

    The antifungal activity of pterophyllin 2, pterophyllin 4, a 5-desmethyl analog of the latter and some of their synthetic intermediates, against three postharvest phytopathogenic fungi, was evaluated. The target fungi were Rhizopus stolonifer, Botrytis cinerea and Monilinia fructicola, which affect fruits worldwide, causing important economic losses. The tests were carried out with imazalil and carbendazim as positive controls. Minimum inhibitory concentrations and minimum fungicidal concentrations were determined, and the morphology of the colonies was examined microscopically. In liquid medium, it was found that pterophyllin 4 exhibited selective fungicidal activity toward M. fructicola, whereas its congener pterophyllin 2 proved to be less potent and not selective and the 5-desmethyl analog of pterophyllin 4 displayed a different activity profile. Morphological changes were observed in the colonies exposed to pterophyllin 4. The results highlighted the importance of small structural features for the antifungal behavior and also suggested that, in Nature, the pterophyllins may act as plant defenses against pathogens. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Application of bacteriophages in post-harvest control of human pathogenic and food spoiling bacteria.

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    Pérez Pulido, Rubén; Grande Burgos, Maria José; Gálvez, Antonio; Lucas López, Rosario

    2016-10-01

    Bacteriophages have attracted great attention for application in food biopreservation. Lytic bacteriophages specific for human pathogenic bacteria can be isolated from natural sources such as animal feces or industrial wastes where the target bacteria inhabit. Lytic bacteriophages have been tested in different food systems for inactivation of main food-borne pathogens including Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica, Shigella spp., Campylobacter jejuni and Cronobacter sakazkii, and also for control of spoilage bacteria. Application of lytic bacteriophages could selectively control host populations of concern without interfering with the remaining food microbiota. Bacteriophages could also be applied for inactivation of bacteria attached to food contact surfaces or grown as biofilms. Bacteriophages may receive a generally recognized as safe status based on their lack of toxicity and other detrimental effects to human health. Phage preparations specific for L. monocytogenes, E. coli O157:H7 and S. enterica serotypes have been commercialized and approved for application in foods or as part of surface decontamination protocols. Phage endolysins have a broader host specificity compared to lytic bacteriophages. Cloned endolysins could be used as natural preservatives, singly or in combination with other antimicrobials such as bacteriocins.

  16. Effects of post-harvest treatment using chitosan from Mucor circinelloides on fungal pathogenicity and quality of table grapes during storage.

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    de Oliveira, Carlos Eduardo Vasconcelos; Magnani, Marciane; de Sales, Camila Veríssimo; Pontes, Alline Lima de Souza; Campos-Takaki, Galba Maria; Stamford, Thayza Christina Montenegro; de Souza, Evandro Leite

    2014-12-01

    The aim of this study was to extract chitosan (CHI) from Mucor circinelloides UCP 050 grown in a corn steep liquor (CSL)-based medium under optimized conditions and to assess the efficacy of the obtained CHI to inhibit the post-harvest pathogenic fungi Aspergillus niger URM 5162 and Rhizopus stolonifer URM 3482 in laboratory media and as a coating on table grapes (Vitis labrusca L.). The effect of CHI coating on some physical, physicochemical and sensory characteristics of the fruits during storage was assessed. The greatest amount of CHI was extracted from M. circinelloides UCP 050 grown in medium containing 7 g of CSL per 100 mL at pH 5.5 with rotation at 180 rpm. CHI from M. circinelloides UCP 050 caused morphological changes in the spores of the fungal strains tested and inhibited mycelial growth and spore germination. CHI coating delayed the growth of the assayed fungal strains in artificially infected grapes, as well as autochthonous mycoflora during storage. CHI coating preserved the quality of grapes during storage, as measured by their physical, physicochemical and sensory attributes. These results demonstrate that edible coatings derived from M. circinelloides CHI could be a useful alternative for controlling pathogenic fungi and maintaining the post-harvest quality of table grapes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Cloning, characterization, expression and antifungal activity of an alkaline serine protease of Aureobasidium pullulans PL5 involved in the biological control of postharvest pathogens.

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    Zhang, Dianpeng; Spadaro, Davide; Valente, Silvia; Garibaldi, Angelo; Gullino, Maria Lodovica

    2012-02-15

    An alkaline protease gene was amplified from genomic DNA and cDNA of the antagonistic yeast-like fungus Aureobasidium pullulans PL5, a biocontrol agent effective against Monilinia laxa on stone fruit and Botrytis cinerea and Penicillium expansum on pome fruits. An open reading frame of 1248 bp encoding a 415-amino acid (aa) protein with a calculated molecular weight (M(r)) of 42.9 kDa and an isoelectric point (pI) of 4.5 was characterized. The cDNAALP5 gene had an 18-amino acid signal peptide, one N-gylcosylation, one histidine active site, and one serine active site. The ALP5 gene with a M(r) of 1351 bp contained two introns. One intron was of 54 bp, while the other was of 50 bp. Protein BLAST and phylogenetic tree analysis of the deduced amino sequences from the cDNAALP5 gene showed that the encoded protein had 100% homology to a protease enzyme (ALP2) of a sea strain of A. pullulans, suggesting that the protein ALP5 was an alkaline serine protease. Expression of ALP5 in Escherichia coli BL21 (DE3), followed by identification with Western-blotting, purification with Ni-NTA and analysis of enzymatic activity, yielded an homogeneous recombinant ALP5 which hydrolysed the substrate casein and inhibited the mycelial growth of the pathogens. At its optimal pH of 10.0 and reaction temperature of 50°C, the recombinant protease exhibited the highest activity towards the substrate casein, though the highest stability was at lower temperatures and pH between 7.0 and 9.0. This study provided the direct evidence that extracellular proteases secreted by the antagonist A. pullulans PL5 played a role in the biocontrol activities against some postharvest pathogens of apple and peach. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. DNA sequence analysis of herbarium specimens facilitates the revival of Botrytis mali, a postharvest pathogen of apple.

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    O'Gorman, Daniel T; Sholberg, Peter L; Stokes, Sarah C; Ginns, J

    2008-01-01

    The fungus Botrytis cinerea has been widely accepted as the species responsible for causing gray mold decay of apple, although a second species causing apple decay, B. mali, was reported in 1931. Botrytis mali was validly published in 1931, nevertheless it has always been considered a doubtful species. To study the relationship of Botrytis isolates causing gray mold on apple, DNA sequence analysis was employed. Twenty-eight Botrytis isolates consisting of 10 species were sampled, including two B. mali herbarium specimens from apple originally deposited in 1932. The DNA sequence analysis of the beta-tubulin and glyceraldehyde-3-phosphate dehydrogenase (G3PDH) genes placed the isolates into groupings with defined species boundaries that generally reflected the morphologically based model for Botrytis classification. The B. cinerea isolates from apple and other host plants were placed in a single clade. The B. mali herbarium specimens however always fell well outside that clade. The DNA sequence analysis reported in this study support the initial work by Ruehle (1931) describing the apple pathogen B. mali as a unique species.

  19. The science, development, and commercialization of postharvest biocontrol products

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    Postharvest biological control agents as a viable alternative to the use of synthetic chemicals have been the focus of considerable research for the last 30 years by many scientists and several commercial companies worldwide. Several antagonists of postharvest pathogens have been identified and tes...

  20. Effect of inoculum size, bacterial species, type of surfaces and contact time to the transfer of foodborne pathogens from inoculated to non-inoculated beef fillets via food processing surfaces.

    Science.gov (United States)

    Gkana, E; Chorianopoulos, N; Grounta, A; Koutsoumanis, K; Nychas, G-J E

    2017-04-01

    The objective of the present study was to determine the factors affecting the transfer of foodborne pathogens from inoculated beef fillets to non-inoculated ones, through food processing surfaces. Three different levels of inoculation of beef fillets surface were prepared: a high one of approximately 10 7  CFU/cm 2 , a medium one of 10 5  CFU/cm 2 and a low one of 10 3  CFU/cm 2 , using mixed-strains of Listeria monocytogenes, or Salmonella enterica Typhimurium, or Escherichia coli O157:H7. The inoculated fillets were then placed on 3 different types of surfaces (stainless steel-SS, polyethylene-PE and wood-WD), for 1 or 15 min. Subsequently, these fillets were removed from the cutting boards and six sequential non-inoculated fillets were placed on the same surfaces for the same period of time. All non-inoculated fillets were contaminated with a progressive reduction trend of each pathogen's population level from the inoculated fillets to the sixth non-inoculated ones that got in contact with the surfaces, and regardless the initial inoculum, a reduction of approximately 2 log CFU/g between inoculated and 1st non-inoculated fillet was observed. S. Typhimurium was transferred at lower mean population (2.39 log CFU/g) to contaminated fillets than E. coli O157:H7 (2.93 log CFU/g), followed by L. monocytogenes (3.12 log CFU/g; P < 0.05). Wooden surfaces (2.77 log CFU/g) enhanced the transfer of bacteria to subsequent fillets compared to other materials (2.66 log CFU/g for SS and PE; P < 0.05). Cross-contamination between meat and surfaces is a multifactorial process strongly depended on the species, initial contamination level, kind of surface, contact time and the number of subsequent fillet, according to analysis of variance. Thus, quantifying the cross-contamination risk associated with various steps of meat processing and food establishments or households can provide a scientific basis for risk management of such products. Copyright © 2016 Elsevier Ltd

  1. New Postharvest Technologies

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    Kidd and West’s discovery of the climacteric in apples in the 1920s and Blackman’s works on respiration of fruits in same time established the basis of modern postharvest plant physiology. Commercial use of controlled atmosphere rapidly expanded in the 1950s along with the in depth research. Ethylen...

  2. Biocontrol of Postharvest Anthracnose of Mango Fruit with Debaryomyces Nepalensis and Effects on Storage Quality and Postharvest Physiology.

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    Luo, Shanshan; Wan, Bin; Feng, Shuhan; Shao, Yuanzhi

    2015-11-01

    Anthracnose is presently recognized as one of the most important postharvest disease of mango worldwide. To control the disease, chemical fungicides for a long time was widely used among fruit farmers, but recently found that pathogen had developed increasingly resistance to it. With people's growing desire of healthy and green food, finding new and environmentally friendly biological control approach was very necessary. In this paper, we provided a kind of new antagonistic yeast which enriched the strain resources and the efficacy of Debaryomyces nepalensis against postharvest anthracnose of mango fruit and the influence on quality parameters were investigated. The results showed that the decay incidence and lesion diameter of postharvest anthracnose of mango treated by D. nepalensis were significantly reduced compared with the control fruit stored at 25 °C for 30 d or at 15 °C for 40 d, and the higher concentration of D. nepalensis was, the better the efficacy of the biocontrol was. Study also found that 1 h was the best treatment duration and antagonistic yeast inoculated earlier had good biocontrol effect on anthracnose. Meanwhile, treatment by D. nepalensis could significantly reduce postharvest anthracnose of mango, delay the decrease in firmness, TSS, TA, and ascorbic acid value, and do not impair surface color during postharvest storage. Moreover, the increase in MDA (malondialdehyde) content and increase in cell membrane permeability of fruit treated by D. nepalensis was highly inhibited. The results suggested D. nepalensis treatment could not only maintain storage quality of mango fruit, but also decrease the decay incidence to anthracnose disease. All these results indicated that D. nepalensis has great potential for development of commercial formulations to control postharvest pathogens of mango fruit. © 2015 Institute of Food Technologists®

  3. Effect of Verticillium dahliae soil inoculum levels on spinach seed infection

    DEFF Research Database (Denmark)

    Sapkota, Rumakanta; Olesen, Merete Halkjær; Deleuran, Lise Christina

    2016-01-01

    Verticillium dahliae is a soilborne pathogen and a threat to spinach seed production. The aim of this study was to understand the relation between V. dahliae soil inoculum and infection in harvested seed. Quantitative polymerase chain reaction was used for quantification of the pathogen. Semifield...... experiments in which spinach was grown in soils with different inoculum levels enabled us to determine a threshold level for V. dahliae DNA of 0.003 ng/g of soil for seed infection to occur. Soils from production fields were sampled in 2013 and 2014 during and before planting, as well as the harvested seed....... Seed from plants grown in infested soils were infected with V. dahliae in samples from both the semifield and open-field experiments. Lower levels of pathogen were found in seed from spinach grown in soils with a scattered distribution of V. dahliae (one or two positive of three soil subsamples) than...

  4. Biocontrol interventions for inactivation of foodborne pathogens on produce

    Science.gov (United States)

    Post-harvest interventions for control of foodborne pathogens on minimally processed foods are crucial for food safety. Biocontrol interventions have the primary objective of developing novel antagonists in combinations with physical and chemical interventions to inactivate pathogenic microbes. Ther...

  5. Rhizoctonia solani infection reduced by bacterial and fungal combination of biofertilizer inoculums on organic potato

    Science.gov (United States)

    Papp, Orsolya; Biro, Borbala; Abod, Eva; Jung, Timea; Tirczka, Imre; Drexler, Dora

    2017-04-01

    Soil biological functioning and proper agrotechnical management are of key importance in organic agriculture. Beneficial microbial inoculums are used either as plant strengthening products (psp) or also as plant protecting products (ppp). Question is, which type of microbes should be applied to certain soil-plant systems to improve yield or reduce the damage of soil-born plant pathogens? Objective of present study was to compare the effect of inoculums 1 (PPS) with plant growth promoting bacterium strains (PGPR) and inoculums 2 (TPB) with potential biocontrol-agents, including both fungi and bacteria in organic potato production. Field experiment was conducted at the Organic Research Station of the Szent István University (Babatpuszta, Hungary). Growth and quality of potato (Solanum tuberosum var. Demon) was studied in the two microbial treatments and control, in four replicates. The PPS inoculums included Pseudomonas protegens, Ps. jessenii and Strenotrophomonas maltophylia, with plant growth promoting (PGPR) effect. TPB inoculums consisted of Trichoderma hartianum, Pseudomonas putida and Bacillus subtilis strains with main biocontrol effects of fungal and bacterium combination. Strains were incubated for 24 hours at 28 oC in a rotary shaker (140 rpm/min) up till cell-number about 1010 cell.ml-1 in Nutrient broth substrate, and mixed to prepare combined inoculums. Each potato tuber was treated by 10 ml inoculums that was added to 100 ml water respectively with only water at the controls. Yield of potato (10 plants/plot) and tuber quality, i.e. the percentage ratio of scabbiness (Streptomyces scabies), Rhizoctonia solani, and Fusarium sp. infection was estimated. Abundance of total aerob and anaerob heterotrophs, total microscopic fungi, pseudomonads bacteria and some sporeforming microorganisms was assessed by the most probable number (MPN) method in soil samples, collected four times during vegetation. Soil enzyme, dehydrogenase (DH) and fluorescein diacetate

  6. The impact of the postharvest environment on the viability and virulence of decay fungi.

    Science.gov (United States)

    Liu, Jia; Sui, Yuan; Wisniewski, Michael; Xie, Zhigang; Liu, Yiqing; You, Yuming; Zhang, Xiaojing; Sun, Zhiqiang; Li, Wenhua; Li, Yan; Wang, Qi

    2018-07-03

    Postharvest decay of fruits, vegetables, and grains by fungal pathogens causes significant economic losses. Infected produce presents a potential health risk since some decay fungi produce mycotoxins that are hazardous to human health. Infections are the result of the interplay between host resistance and pathogen virulence. Both of these processes, however, are significantly impacted by environmental factors, such as temperature, UV, oxidative stress, and water activity. In the present review, the impact of various physical postharvest treatments (e.g., heat and UV) on the viability and virulence of postharvest pathogens is reviewed and discussed. Oxidative injury, protein impairment, and cell wall degradation have all been proposed as the mechanisms by which these abiotic stresses reduce fungal viability and pathogenicity. The response of decay fungi to pH and the ability of pathogens to modulate the pH of the host environment also affect pathogenicity. The effects of the manipulation of the postharvest environment by ethylene, natural edible coatings, and controlled atmosphere storage on fungal viability are also discussed. Lastly, avenues of future research are proposed.

  7. Post-harvest loss reduction

    NARCIS (Netherlands)

    Gogh, van Bart; Boerrigter, Henry; Noordam, Maryvon; Ruben, Ruerd; Timmermans, Toine

    2017-01-01

    This paper was written by experts from Wageningen University & Research (WUR), representing their combined expertise on food chains, post-harvest technology, sustainability, food security, economics, and food safety. The paper was drafted at the request of the Dutch Ministry of Economic Affairs

  8. Evaluation of Muscodor suthepensis strain CMU-Cib462 as a postharvest biofumigant for tangerine fruit rot caused by Penicillium digitatum.

    Science.gov (United States)

    Suwannarach, Nakarin; Bussaban, Boonsom; Nuangmek, Wipornpan; Pithakpol, Wasna; Jirawattanakul, Bantoon; Matsui, Kenji; Lumyong, Saisamorn

    2016-01-15

    This study investigated both the in vitro and in vivo biofumigant ability of the endophytic fungus Muscodor suthepensis CMU-Cib462 to control Penicillium digitatum, the main cause of tangerine fruit rot. Volatile compounds from M. suthepensis inhibited mycelial growth of the pathogen. The most abundant compound was 2-methylpropanoic acid, followed by 3-methylbutan-1-ol. They showed median effective doses (ED50) on P. digitatum growth of 74.91 ± 0.73 and 250.29 ± 0.29 µL L(-1) airspace respectively. Rye grain was found to be a suitable solid medium for M. suthepensis inoculum production. The results indicated that mycofumigation with a 30 g rye grain culture of M. suthepensis for 12 h controlled tangerine fruit rot. The percentage weight loss and soluble solids concentration of fumigated tangerines were similar to those of non-infected and non-fumigated fruits. Muscodor suthepensis has potential as a biofumigant for controlling postharvest disease of tangerine fruit. © 2015 Society of Chemical Industry.

  9. The Growth of Root Rot Disease on Pepper Seed Applied by Trichoderma Harzianum Inoculum

    Directory of Open Access Journals (Sweden)

    S. Sofian

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Root rot disease on pepper caused by Phytophthora capsici is one of the most important diseases on pepper. The using of antagonistic fungus of Trichoderma harzianum as a biological control agent of the pathogen is one of the important alternatives in controlling P. capsici without causing negative effects on the environment. The objectives of the research were to study about the ability of T. harzianum inoculum application in inhibiting the development of root-rot disease, influenced the growth of pepper seed, to studythe effective length time application of T. harzianum inoculum in inhibiting the development of root rot disease, and increased the growth of pepper seedlings. This research was arranged in a completely randomized design, with five treatments of length time application of T. harzianum inoculum i.e. control treatment without applicationtime of T. harzianum inoculum (K, application time of T. harzianum inoculum for 0 week (S0, application time of T. harzianum inoculum for 1 week (S1, application time of T. harzianum inoculum for two weeks (S2, application time of T. harzianum inoculum for three weeks (S3, and application time of T. harzianum inoculum for 4 weeks (S4 before planting. Each treatment was repeated15 times. The observed parameterswere disease percentage, the inhibition of antagonistic fungus, disease infection rate, plant height, number of leaves, wet and dry weight of plant, stem and leaves on pepper seed, and P. capsici population density. The result showed that application time of T. harzianum inoculumfor 4 weeks (S4 before planting is the most effective time in inhibiting the development of root rot disease than the other treatment sand also had significant effect on increasing the growth of pepper seed. The antagonism test showed that T. harzianum could inhibit P. capsiciin vitro. This result proves that application time of T. harzianum inoculums

  10. Application of real-time PCR to postharvest physiology – DNA isolation

    Science.gov (United States)

    Real-time PCR technology has been widely used in the postharvest plant physiology research. One of the difficulties to isolate DNA from plant martial and pathogen cells is the presence of rigid polysaccharide cell walls and capsules, which physically protect DNA from cell lysis. Many materials requi...

  11. Effects of post-harvest handling conditions on internalization and growth of Salmonella enterica in tomatoes

    Science.gov (United States)

    Internalization during post-harvest handling is a significant route of tomato contamination by phytopathogens and foodborne human pathogens. This study was conducted to determine the effect of immersion time, immersion depth, and the temperature differential between bacterial suspension and tomato p...

  12. Effect of Trichoderma on horticultural seedlings' growth promotion depending on inoculum and substrate type.

    Science.gov (United States)

    Marín-Guirao, J I; Rodríguez-Romera, P; Lupión-Rodríguez, B; Camacho-Ferre, F; Tello-Marquina, J C

    2016-10-01

    The biostimulant effect of Trichoderma spp. on horticultural crops are highly variable. Thus, practical use of Trichoderma sp. requires feasible formulated products and suitable substrates. This study evaluates the survival and the growth-promotion effect of a Trichoderma saturnisporum rice formulation compared with a nonformulated conidia suspension (seven treatments in total), on tomato, pepper and cucumber seedlings grown in two substrates: (i) rich in organic matter (OM) and (ii) mineral substrate without OM. The results showed beneficial effects on seedling growth in the OM-rich substrate when T. saturnisporum rice formulation (mainly at maximum concentration) was applied, but the effects were opposite when the mineral substrate without OM was used. The effects were closely linked to the level of inoculum in the substrate, which was greater upon application of the formulated inoculum as opposed to the nonformulated one. The use of rice to prepare the inoculum of T. saturnisporum seems to be promising for seedling growth in the nursery when it is applied in a substrate that is rich in organic matter, but it must be considered that under certain conditions of food shortage, Trichoderma sp. could show pathogenicity to seedlings. This study provides evidence of the complexity inherent in the use of micro-organisms in agriculture, while also confirming that the activity of the biofertilizers based on Trichoderma depends on the type of inoculum and its concentration, as well as the properties of the medium in which the fungi develop. Further studies assessing the effectiveness or possible pathogenicity of Trichoderma in different soils under greenhouse conditions must be addressed. © 2016 The Society for Applied Microbiology.

  13. Use of milk-based kombucha inoculum for milk fermentation

    Directory of Open Access Journals (Sweden)

    Kolarov Ljiljana A.

    2009-01-01

    Full Text Available In this investigation fermented milk beverages with 0.9% of milk fat were produced using 10 and 15% (v/v of traditional and milk-based kombucha inoculum by application of appropriate technological process. Milk fermentation using two types and concentrations of kombucha inoculum were stopped when the pH reached 4.5. Sigmoidal fermentation profiles were noticed with traditional kombucha inoculums and linear with milk-based kombucha inoculums. Chemical content and physico-chemical characteristics of kombucha fermented milk beverages were typical and yoghurt-like for all obtained products. The best textural and sensory characteristics possesed beverage obtained in fermentation of milk using 10% (v/v of milk-based kombucha inoculum.

  14. Physiological Characterization of Fungal Inoculum for Biotechnological Remediation of Soils

    Directory of Open Access Journals (Sweden)

    Nara Ballaminut

    2014-08-01

    Full Text Available The aim of this work was to study the bioremediating potential of Lentinus crinitus CCIBt2611 according to the physiological condition of the inoculum. Inoculum was prepared using sugarcane ground husk (C:N 90, at several physiological ages and applied in soil contaminated with pentachlorophenol. The inoculum's potential was assessed by evaluating the mycelium's vigor at soil's colonization, determination of peroxidase and phenoloxidase activities, in vitro degradation of Remazol Brilliant Blue R and in vivo degradation of pentachlorophenol. The results showed that the assessed parameters were relevant to identify the quality of the inoculum. For L. crinitus, 10 day old inoculum showed good soil-colonization speed with significant enzymatic activities, indicating the role of Manganese-dependent peroxidase and laccase in degradation, and efficient degradation of pentachlorophenol.

  15. Review on postharvest technology of banana fruit

    African Journals Online (AJOL)

    mu

    2013-02-13

    Feb 13, 2013 ... The aim of this review is in threefold: First, to explore the effect of different preharvest treatments on postharvest ... biochemical changes in banana during development, maturation, ripening and storage were reviewed. Third, postharvest ..... at full mature stage for local domestic market (Gowen,. 1995).

  16. Survey of postharvest handling, preservation and processing ...

    African Journals Online (AJOL)

    Survey of postharvest handling, preservation and processing practices along the camel milk chain in Isiolo district, Kenya. ... Despite the important contribution of camel milk to food security for pastoralists in Kenya, little is known about the postharvest handling, preservation and processing practices. In this study, existing ...

  17. Post-harvest Proteomics and Food Security

    NARCIS (Netherlands)

    Pedreschi Plasencia, R.P.; Lurie, S.; Hertog, W.; Nicolai, B.; Mes, J.J.; Woltering, E.J.

    2013-01-01

    To guarantee sufficient food supply for a growing world population, efforts towards improving crop yield and plant resistance should be complemented with efforts to reduce postharvest losses. Post-harvest losses are substantial and occur at different stages of the food chain in developed and

  18. Impact of relative humidity, inoculum carrier and size, and native microbiota on Salmonella ser. Typhimurium survival in baby lettuce.

    Science.gov (United States)

    López-Gálvez, Francisco; Gil, Maria Isabel; Allende, Ana

    2018-04-01

    The effects of relative humidity (RH), fluctuating climate conditions, inoculum size and carrier on the survival of Salmonella enterica serovar Typhimurium on baby lettuce in environmental test chambers were studied. Buffered peptone water (BPW), distilled water (DW), and irrigation water (IW) were compared as inoculum carriers. Additionally, survival of Salmonella in suspensions prepared using filtered and unfiltered IW was assessed. Salmonella Typhimurium survived better on baby lettuce plants at high RH independently of the inoculum size. When lettuce plants were grown under fluctuating environmental conditions, Salmonella survival was similar under both RH conditions. Regarding the inoculum carrier, the inoculated microorganism survived better on lettuce plants when BPW was used as carrier both at high and low RH. Survival rate of Salmonella in IW was affected by the presence of native microbiota. Native microbiota present in IW did not affect survival of Salmonella or the levels of mesophilic bacteria on the baby lettuce leaves. The information obtained in the present study contributes to the knowledge on the effect of environmental conditions on pathogenic bacteria survival on growing edible plants. These results are useful when selecting the methodology to carry out experimental studies on the survival of microbial pathogens under different pre-harvest conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Selection of inoculum size and Saccharomyces cerevisiae strain for ...

    African Journals Online (AJOL)

    SAM

    2014-07-02

    Jul 2, 2014 ... The aim of this work was to select an inoculum concentration and a ... (UFPEDA 1238 and UFPEDA 1334) were used to ferment a culture medium containing .... quantified by HPLC (Agilent HP 1100, Germany) in an Aminex.

  20. Influence of Inoculum Content on Performance of Anaerobic Reactors for Treating Cattle Manure using Rumen Fluid Inoculum

    OpenAIRE

    Sunarso; S. Johari; I N. Widiasa; Budiyono

    2009-01-01

    Biogas productions of cattle manure using rumen fluid inoculums were determined using batch anaerobic digesters at mesophilic temperatures (room and 38.5 oC). The aim of this paper was to analyze the influence of rumen fluid contents on biogas yield from cattle manure using fluid rumen inoculums. A series of laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure (M) was fed to each biodigester and mixed with rumen fluid (...

  1. Postharvest physicochemical properties of cucumber fruits ...

    African Journals Online (AJOL)

    BISHOP

    2016-12-14

    Dec 14, 2016 ... Department of Food Science and Technology, Federal University of Technology, Akure, .... The diameter was measured using a digital Vernier caliper (Model ..... Training manual on postharvest handling and marketing of.

  2. Postharvest biology and technology research and development ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    Sep 3, 2008 ... The applications of biological control agents in pre- and post-harvest operations and .... production, with regards to food safety, operator health and the ... and to work out sustainable compliance modalities for small-scale ...

  3. Food Safety Impacts from Post-Harvest Processing Procedures of Molluscan Shellfish.

    Science.gov (United States)

    Baker, George L

    2016-04-18

    Post-harvest Processing (PHP) methods are viable food processing methods employed to reduce human pathogens in molluscan shellfish that would normally be consumed raw, such as raw oysters on the half-shell. Efficacy of human pathogen reduction associated with PHP varies with respect to time, temperature, salinity, pressure, and process exposure. Regulatory requirements and PHP molluscan shellfish quality implications are major considerations for PHP usage. Food safety impacts associated with PHP of molluscan shellfish vary in their efficacy and may have synergistic outcomes when combined. Further research for many PHP methods are necessary and emerging PHP methods that result in minimal quality loss and effective human pathogen reduction should be explored.

  4. Evaluation of food additives as alternative or complementary chemicals to conventional fungicides for the control of major postharvest diseases of stone fruit for the control of major postharvest diseases of stone fruit

    Science.gov (United States)

    Among more than twenty food additives and GRAS (generally regarded as safe) compounds that were tested at three concentrations in in vivo primary screenings with several cultivars of California peaches, nectarines, and plums that had been artificially inoculated with seven major postharvest pathogen...

  5. Integrated Management of Causal Agents of Postharvest Fruit Rot of Apple

    Directory of Open Access Journals (Sweden)

    Mila Grahovac

    2011-01-01

    Full Text Available One of the major causes of poor quality and fruit loss (during storage and transportare diseases caused by phytopathogenic fungi. Economic losses which are the consequenceof the phytopathogenic fungus activity after harvest exceed the losses in the field.Themost important postharvest fungal pathogens of apple fruits are: Botrytis cinerea Pers. exFr., Penicillium expansum (Lk. Thom., Cryptosporiopsis curvispora (Peck. Grem., Colletotrichumgloeosporioides (Penz. Sacc., Monilinia sp., Gloeosporium album Osterw, Alternaria alternata(Fr. Keissler, Cladosporium herbarium Link., Cylindrocarpon mali (Alles. Wollenw., Stemphyliumbotryosum Wallr. The use of available protection technologies can significantly reducelosses caused by pathogens in storage. The concept of integrated pest management (IPMin apple fruits i.e. sustainable approach in control of causal agents of postharvest fruit rot,using cultural, physical, biological and chemical measures, to minimize economic, healthand risks to consumers and environment, is presented in the paper.

  6. The Effect of Feed to Inoculums Ratio on Biogas Production Rate from Cattle Manure Using Rumen Fluid as Inoculums

    Directory of Open Access Journals (Sweden)

    S. Sunarso

    2010-12-01

    Full Text Available In this study, rumen fluid of animal ruminant was used as inoculums to increase biogas production rate from cattle manure at mesophilic condition. A series of laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure was fed to each biodigester and mixed with rumen fluid and tap water resulting five different feed to inoculum (F/I ratios (i.e. 17.64, 23.51, 35.27, and 70.54. The operating temperatures were varied at room temperature. The results showed that the rumen fluid inoculated to biodigester significantly effected the biogas production. Rumen fluid inoculums caused biogas production rate and efficiency increase more than two times in compare to manure substrate without rumen fluid inoculums. At four F/Is tested, after 80 days digestion, the biogas yield were 191, 162, 144 and 112 mL/g VS, respectively. About 80% of the biogas production was obtained during the first 40 days of digestion. The best performance of biogas production will be obtained if F/I ratio is in the range of 17.64 to 35.27 (correspond to 25 – 50 % of rumen fluid. The future work will be carried out to study the dynamics of biogas production if both the rumen fluid inoculums and manure are fed in the continuous system

  7. Postharvest Ripening and Shelf Life of Mango ( Mangifera indica L ...

    African Journals Online (AJOL)

    Postharvest Ripening and Shelf Life of Mango ( Mangifera indica L.) Fruit as Influenced by ... evaluate the influence of 1-Methylcyclopropene (1-MCP) and polyethylene packaging (PP) on postharvest storage of mango. ... HOW TO USE AJOL.

  8. Pre-harvest treatments with fungicides and post-harvest dips in sodium bicarbonate to control postharvest decay in stone fruit.

    Science.gov (United States)

    D'Aquino, S; Barberis, A; Satta, D; De Pau, L; Schirra, M

    2012-01-01

    The objective of this study was to evaluate the effectiveness of different commercial formulations of fungicides containing one or more active ingredients in controlling postharvest decay of Thyrinthos and Boccuccia apricots, Red top peaches and Caldesi nectarines. Field treatments consisted of two sprays with cupric compounds, at the end of leaf fall and before bud swelling, one with sulfur compound, at fruit about half final size stage, and one with one of the following commercial formulations at the label suggested rates, one week before harvest: Teldor (fenexamid 50%; Bayer Crop Protection), Folicur (Tebuconazole 4.35%; Bayer Crop Protection), Signum (boscalid 26.7%, pyraclostrobin 6.7%; Basf Crop Protection), Score (difenoconazole 23.23%, Syngenta Crop Protection) and Switch (cyprodinil 37.5%, fludioxonil 25%, Syngenta Crop Protection). After harvest the fruit were stored for 1 week at 6 degrees C and 90% RH followed by 1 week at 20 degrees C and 60% RH to simulate retail conditions, or placed directly at 20 degrees C. All formulations significantly reduced decay in all cultivars. Switch, Signum and Folicur were the most active, while Score was slightly less effective. Teldor activity was low, especially in Thyrintos apricots, where the percentage of rotten fruit was slightly lower than in control fruit. Brown rot was the most representative disease, but in apricots a high percentage of fruit was affected by blue mold and grey mold. Rhizopus rot generally developed as a secondary disease on fruit previously affected by other pathogens and was more frequent in control and Teldor treated fruit. Preharvest sprays with Signum 3 days before harvest reduced postharvest decay after 1 week storage at 20 degrees C in Glo haven peaches and Venus nectarine harvested at advanced stage of maturity. Combining pre-harvest sprays with Signum and a 2-min postharvest dip in 2% sodium bicarbonate at 20 degrees C further reduced decay. In Sothern regions of Italy, the use of

  9. Exploitation of microbial antagonists for the control of postharvest diseases of fruits: a review.

    Science.gov (United States)

    Dukare, Ajinath Shridhar; Paul, Sangeeta; Nambi, V Eyarkai; Gupta, Ram Kishore; Singh, Rajbir; Sharma, Kalyani; Vishwakarma, Rajesh Kumar

    2018-01-16

    Fungal diseases result in significant losses of fruits and vegetables during handling, transportation and storage. At present, post-production fungal spoilage is predominantly controlled by using synthetic fungicides. Under the global climate change scenario and with the need for sustainable agriculture, biological control methods of fungal diseases, using antagonistic microorganisms, are emerging as ecofriendly alternatives to the use of fungicides. The potential of microbial antagonists, isolated from a diversity of natural habitats, for postharvest disease suppression has been investigated. Postharvest biocontrol systems involve tripartite interaction between microbial antagonists, the pathogen and the host, affected by environmental conditions. Several modes for fungistatic activities of microbial antagonists have been suggested, including competition for nutrients and space, mycoparasitism, secretion of antifungal antibiotics and volatile metabolites and induction of host resistance. Postharvest application of microbial antagonists is more successful for efficient disease control in comparison to pre-harvest application. Attempts have also been made to improve the overall efficacy of antagonists by combining them with different physical and chemical substances and methods. Globally, many microbe-based biocontrol products have been developed and registered for commercial use. The present review provides a brief overview on the use of microbial antagonists as postharvest biocontrol agents and summarises information on their isolation, mechanisms of action, application methods, efficacy enhancement, product formulation and commercialisation.

  10. Review on postharvest technology of banana fruit | Hailu | African ...

    African Journals Online (AJOL)

    These include disinfecting, packaging and storage temperature. Pre- and postharvest treatments were found to have an effect on postharvest quality of banana, suggesting that postharvest quality of produce subjected to preharvest treatments should be assessed from a quality improvement, maintenance and consumer ...

  11. Postharvest Losses in Africa: Analytical Review and Synthesis ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Across Africa, postharvest losses along the food chain from farm to fork jeopardize the food security of resource-poor farmers. Reducing postharvest losses can help increase food availability and improve access to food, nutritional quality, food safety, and farmers' incomes. Data on postharvest losses is in short supply.

  12. Association of Pectolytic Fluorescent PSeudomonas with Postharvest Rots of Onion

    Directory of Open Access Journals (Sweden)

    H.H. El-Hendawy

    2004-12-01

    Full Text Available Five isolates of pectolytic fluorescent pseudomonads were obtained from a rotted onion bulb and identified as Pseudomonas marginalis. At both 4 and 25oC, all isolates caused soft rot to detached plant parts of onion and to carrot, celery, cucumber, pepper, spinach, tomato and turnip (but not garlic. They did not however cause any symptoms in living plants of these same species. These results suggest that the onion isolates are a postharvest pathogen which is not destructive in the field but becomes a threat to fresh vegetables stored at low-temperature. Analysis of cellulosolytic and pectic enzymes revealed that pectic lyases, but not polygalacturonases, pectin methyl esterases and cellulases were produced in culture by each isolate.

  13. Gamma radiation influences postharvest disease incidence of pineapple fruits

    International Nuclear Information System (INIS)

    Damayanti, M.; Sharma, G.J.; Kundu, S.C.

    1992-01-01

    The application of gamma radiation for improving the storage of pineapple fruits [Ananas comosus (L.) Merr. cv. Queen] has been studied in an attempt to reduce decay caused by fungal pathogens such as Ceratocystis paradoxa (Dade)-Moreau and Penicillium purpurogenum Stoll. Gamma radiation at 50, 75, 100, 150, and 250 Gy improved shelf life. The maximum tolerable dose was approximately 250 Gy. Fruits irradiated with up to 150 Gy and then stored at 25 to 28C maintained their texture better than did the controls. Radiation, particularly at doses 250 Gy, caused browning of the skin and softening of tissues. Browning increased with increasing radiation dose and storage duration. Excessively high doses promoted spoilage. Doses in the range of 50 to 250 Gy, in combination with storage at 11 to 13C, can be used to reduce postharvest losses in pineapple due to fungal diseases and senescence, thereby extending shelf life

  14. Effect of mushroom ( Pleurotus tuber-regium ) inoculums on crude ...

    African Journals Online (AJOL)

    Pollution of soils by crude oil in Niger-Delta of Nigeria has brought untold hardship to the inhabitants of the region. This study was carried out in 2010/2011 and 2011/2012 to determine the effect of Pleurotus tuber-regium (mushroom) inoculums on crude oil polluted soil on stover and grain yields and as well as cob length ...

  15. 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...

  16. Use of bacillus subtilis strains to inhibit postharvest pathogenic fungi

    International Nuclear Information System (INIS)

    Arras, G.; Gambella, F.; Demontis, S.; Petretto, A.

    1995-01-01

    An isolate (87) of the bacillus subtilis strains isolated from cold stored citrus fruit 13 proved to inhibit the growth in vitro of the penicillium italicum used in the experiment (from 50.6% to 92.2%) and to inhibit botrytis cinerea (from 65.3% to 95.9%). A further test, superimposing on plates containing PDA strains Nos. 13, 173, and 160, totally inhibited the fungi. Tested in vivo on artificially bruised oranges, they significantly inhibited two fungi

  17. Postharvest biology and technology of pomegranate.

    Science.gov (United States)

    Pareek, Sunil; Valero, Daniel; Serrano, María

    2015-09-01

    Pomegranate is a subtropical and tropical fruit of great importance from a health point of view. Despite increasing consumer awareness of the health benefits of pomegranate, consumption of the fruit is still limited owing to poor postharvest handling, storage recommendations, short shelf life and quality deterioration during transportation, storage and marketing. The occurrence of physiological disorders such as husk scald, splitting and chilling injury is another challenge reducing marketability and consumer acceptance. Recently, notable work on postharvest biology and technology has been done. Pomegranate is highly sensitive to low-oxygen (pomegranate fruit is excessive weight loss, which may result in hardening of the husk and browning of the rind and arils. To reduce chilling injury incidence and to extend storability and marketing of pomegranates, good results were obtained with polyamine, heat, salicylic acid, methyl jasmonate or methyl salicylate treatments prior to cold storage. This article reviews the maturity indices, changes during maturation and ripening, postharvest physiology and technology of pomegranate fruit as well as the various postharvest treatments for maintaining fruit quality. © 2015 Society of Chemical Industry.

  18. Biochemical methane potential (BMP) of artichoke waste: the inoculum effect.

    Science.gov (United States)

    Fabbri, Andrea; Serranti, Silvia; Bonifazi, Giuseppe

    2014-03-01

    The aim of this work was to investigate anaerobic digestibility of artichoke waste resulting from industrial transformation. A series of batch anaerobic digestion tests was performed in order to evaluate the biochemical methane potential of the matrix in respect of the process. A comparison of the different performances of the laboratory-scale reactors operating in mesophilic conditions and utilizing three different values of the inoculum/substrate ratio was carried out. The best performance was achieved with an inoculum/substrate ratio of 2. Artichoke-processing byproducts showed a classical organic waste decomposition behaviour: a fast start-up phase, an acclimation stage, and a final stabilization phase. Following this approach, artichoke waste reached chemical oxygen demand removal of about 90% in 40 days. The high methane yield (average 408.62 mL CH4 gvs (-1) voltatile solids), makes artichoke waste a good product to be utilized in anaerobic digestion plants for biogas production.

  19. CONTROL OF POSTHARVEST TOMATO ROT BY SPORE SUSPENSION AND ANTIFUNGAL METABOLITES OF TRICHODERMA HARZIANUM

    Directory of Open Access Journals (Sweden)

    Momein H. El-Katatny

    2012-06-01

    Full Text Available Rot of cherry tomato (Lycopersicon esculentum fruits caused by several fungal pathogens is a detrimental disease leading to substantial yield loses worldwide. Alternaria isolates were the most common fungal species isolated from healthy or rotten fruits. Trichoderma harzianum spore suspension and culture filtrate were tested for their antagonistic activity on controlling tomato fruit rot. T. harzianum isolates suppressed or interfered with the growth of different postharvest tomato fungal pathogens albeit at different degrees. Their culture filtrate inhibited pathogen spore germination possibly due to the released extracellular diffusible metabolite(s. Besides, aberrant morphology of conidia was observed with deformation of hyphal tips. Furthermore, the resulting mycelia appeared desiccated with coagulated protoplasm leading to complete collapse of protoplasm in presence of T. harzianum culture filtrate. Application of T. harzianum spores to tomato fruits decreased disease severity significantly with the most profound effect at higher spore concentrations (108 cells per ml. Similarly, culture filtrate of T. harzianum prevented pathogen spore germination on the surface of tomato fruits leading to decreased incidence of rot symptoms at high culture filtrate concentrations. This work provides strong evidence that T. harzianum is a competent antagonist and its spore suspension and culture filtrate can be used efficiently to control postharvest tomato rot.

  20. Zingiber zerumbet flower stem postharvest characterization

    Directory of Open Access Journals (Sweden)

    Charleston Gonçalves

    2017-05-01

    Full Text Available About the Zingiber zerumbet little is known about its cut flower postharvest and market, despite its high ornamental potential. The inflorescences, which resemble a compact cone, emerge from the base of the plants and start with green color changing to red with the age. This study objective was to characterize floral stem of ornamental ginger in two cultivate conditions and to evaluate the longevity of those submitted to post-harvest treatments. Flower stems were harvest from clumps cultivated under full sun and partial shade area, and were submitted to the postharvest treatments: complete flower immersion in tap water (CFI or only the base stem immersion (BSI. The flower stems harvested from clumps at partial shade presented higher fresh weight, length and diameter of the inflorescences compared to flower stems harvested from clumps at full sun area. The flower stem bracts cultivated in full sun area changed the color from green to red 10.69 and 11.94 days after BSI and CFI postharvest treatments, and the vase life were 22.94 and 28.19 days, respectively. Flower stem harvest in partial shade area change the color only after 18.94 and 18.43 days and the vase life durability was 27.56 and 31.81, respectively. The complete immersion of the flower stem increase the vase life durability in 5.25 and 4.25 days compared to flowers kept with the stem base immersed only, in flower stems harvested from clumps cultivated in full sun area and partial shade area, respectively. Flower stems harvested from clumps cultivated in partial shade area and completely immerse in tap water during 3 hours increase the vase life durability in 8.87 days compared to flowers harvested from clumps cultivated in full sun area and base immersed only.

  1. Activation of inoculum microorganism from dairy cattle feces

    Science.gov (United States)

    Ayuningtyas, Widya D.; Ridwan, Roni; Joni, I. M.; Marlina, E. T.; Harlia, Ellin

    2018-02-01

    Coal produces Coal Bed Methane (CBM) which is formed both biogenically and thermogenically. Lignite is not utilized optimally because it has low heat content and productivity time limit that decreases CBM production. In order to utilize lignite waste, adding inoculum consortium microorganism from dairy cattle waste as starter for biogas process can be a solution. This study aimed to produce inoculum consortium microorganism as biogas starter from dairy cattle feces through in vitro activation process by Theoudorou modification method. The research used complete randomized design with 3 replications. The treatments were blank (R0), 100% concentrate (R1), 70% concentrate+30% grass (R2), 70% grass+30% concentrate (R3) and 100% grass (R4). All treatments were added by buffer solution and feces with ratio of 2:1 into 100 ml serum injection bottle with anaerobic conditions. The parameters observed were gas production, pH and gas kinetics (orskov's equation) for 2, 4, 6, 8, 10, 12, 24 and 48 hours. The results showed that the treatment had significant effect (P <0.05) on the observed parameters. The highest total gas production was for R2 and R3 treatments with total production of 91.17 ml and 101.17 ml, pH (6.62 and 6.57), maximum gas production (94.03 and 97.62 ml), speed of gas production (0.066 and 0.084 ml/hour). There is not a significant difference for both the treatments. The source of inoculum consortium microorganisms for biogas starter selected based on the observed parameters and potential availability of proteolytic and fibrocytic microorganisms is R2 (70% concentrate +30% grass).

  2. Combining Post-Harvest Fish Value Chain and Social Change ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    , they are not achieving their full potential in Africa. This project will examine interventions to reduce poverty and to improve food and nutrition security using post-harvest innovations in the fish value chain. Post-harvest handling in Zambia and ...

  3. Effects of pre- and postharvest calcium treatments on shelf life and postharvest quality of broccoli microgreens

    Science.gov (United States)

    Microgreens’ extremely short shelf life limits their commercial usage. The objective of this study is to compare the effect of pre- and post- harvest treatments using different forms of calcium on the postharvest quality and shelf-life of broccoli microgreens. Preharvest spray with calcium lactate, ...

  4. Effect of ultraviolet-C light on postharvest decay of strawberry

    International Nuclear Information System (INIS)

    Nigro, F.; Ippolito, A.; Salerno, M.; Lattanzio, V.

    2000-01-01

    The effect of ultraviolet-C light (u.v.-C) at low doses on postharvest decay of strawberries caused by Botrytis cinerea and other pathogens was investigated. Phenylalanine ammonia-lyase (PAL) activity and ethylene production, as influenced by ultraviolet-C irradiation, were also determined. Strawberries (cv. ‘Pajaro’) from plants that had been treated with chemicals against grey mould were irradiated with u.v.-C doses ranging from 0.25 to 4.00 kJ m-2 and inoculated with B. cinerea at different times (0, 12, 24 and 48 hours) after irradiation. To assess the effect of u.v.-C light on the naturally occurring postharvest decay, organically grown strawberries were also used. After treatment the strawberries were stored at 20±1°C or at 3°C. u.v.-C doses at 0.50 and 1.00 kJ m-2 significantly reduced botrytis storage rot arising from both artificial inoculations and natural infections in comparison with the unirradiated control. The doses shown to reduce botrytis rot produced an increase in PAL activity 12 h after irradiation; this result indicates the activation of metabolic a pathway related to the biosynthesis of phenolic compounds, which are usually characterized by antifungal activity. In addition, u.v.-C irradiation caused an increase in ethylene production proportional to the doses applied, reaching the highest value 6 h after treatment. The overall results from these investigations indicate that treatment with low u.v.-C doses produces a reduction in postharvest decay of strawberries related to induced resistance mechanisms. Moreover, a germicidal effect of reducing external contaminating pathogens cannot be excluded

  5. Zeolite and swine inoculum effect on poultry manure biomethanation

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Fotidis, Ioannis; Zaganas, I.D.

    2013-01-01

    Poultry manure is an ammonia-rich substrate that inhibits methanogenesis, causing severe problems to the anaerobic digestion process. In this study, the effect of different natural zeolite concentrations on the mesophilic anaerobic digestion of poultry waste inoculated with well-digested swine...... manure was investigated. A significant increase in methane production was observed in treatments where zeolite was added, compared to the treatment without zeolite.Methane production in the treatment with 10 g dm-3 of natural zeolite was found to be 109.75% higher compared to the treatment without...... zeolite addition. The results appear to be influenced by the addition of zeolite, which reduces ammonia toxicity in anaerobic digestion and by the ammonia-tolerant swine inoculum....

  6. Zeolite and swine inoculum effect on poultry manure biomethanation

    Science.gov (United States)

    Kougias, P. G.; Fotidis, I. A.; Zaganas, I. D.; Kotsopoulos, T. A.; Martzopoulos, G. G.

    2013-03-01

    Poultry manure is an ammonia-rich substrate that inhibits methanogenesis, causing severe problems to the anaerobic digestion process. In this study, the effect of different natural zeolite concentrations on the mesophilic anaerobic digestion of poultry waste inoculated with well-digested swine manure was investigated. A significant increase in methane production was observed in treatments where zeolite was added, compared to the treatment without zeolite.Methane production in the treatment with 10 g dm-3 of natural zeolite was found to be 109.75% higher compared to the treatment without zeolite addition. The results appear to be influenced by the addition of zeolite, which reduces ammonia toxicity in anaerobic digestion and by the ammonia-tolerant swine inoculum.

  7. Biocontrol with Trichoderma species for the management of postharvest crown rot of banana

    Directory of Open Access Journals (Sweden)

    G. Sangeetha

    2009-09-01

    Full Text Available Lasiodiplodia theobromae and Colletotrichum musae cause the postharvest crown rot disease complex of banana. In vitro experiments evaluated the effect of twelve isolates of Trichoderma spp. from the soil of organic banana orchards (‘native isolates’ and eight isolates of Trichoderma spp. from culture collections (‘introduced isolates’ on the two pathogens. The native and introduced Trichoderma spp. had varied antagonistic effects against the two pathogens. Eight Trichoderma spp. isolates effective in the in vitro assays were evaluated singly on fruits both at room temperature and in cold storage. Single antagonists did not satisfactorily control crown rot on the fruits as compared with the fungicide carbendazim. However, two isolates of T. viride, one of T. harzianum and one of T. koningii performed well when applied singly, and these were selected for evaluation in isolate mixtures. There was very little antagonism between these isolates. Of 11 two-way, three-way and four-way mixtures of these isolates, the four-way and a three-way mixtures reduced crown rot incidence, both at room temperature and in cold storage, giving better control than carbendazim. The study identified consortia of compatible Trichoderma antagonists with superior biocontrol potential for the management of the postharvest crown rot complex of banana.

  8. Postharvest changes in glycoalkaloid content of potatoes.

    Science.gov (United States)

    Friedman, M; McDonald, G M

    1999-01-01

    Potatoes contain antinutritional and potentially toxic compounds including inhibitors of digestive enzymes, hemagglutinins, and glycoalkaloids. Solanum glycoalkaloids are reported to inhibit cholinesterase, disrupt cell membranes, and induce teratogenicity. In this overview, we describe the role of potatoes in the human diet, reported changes in glycoalkaloid content of fresh and processed potatoes during storage, under the influence of light and radiation, following mechanical damage, and as a result of food processing. Also covered are safety aspects and suggested research needs to develop a protocol that can be adopted by the potato producers and processors to minimize post-harvest synthesis of glycoalkaloids in potatoes. Reducing the glycoalkaloid content of potatoes will provide a variety of benefits extending from the farm to processing, shipping, marketing, and consumption of potatoes and potato products. A commercially available ELISA kit is described which permits rapid assay of glycoalkaloid content of parts of the potato plant including leaves, tubers, and peel, as well as processed potato products including french fries, chips, and skins. Understanding the multiple overlapping aspects of glycoalkaloids in the plant and in the diet will permit controlling postharvest glycoalkaloid production for the benefit of the producer and consumer.

  9. Postharvest characteristics of two cultivars of cauliflower

    Directory of Open Access Journals (Sweden)

    Adenilson Mroginski de Souza

    2010-06-01

    Full Text Available The cauliflower has a great economic importance, especially for small producers, and it turns out to be a profitable crop in small areas. However, at postharvest period it is difficult to store it at a given room temperature due to sweating and a heavy breathing process, which leads to a discoloration of the inflorescence. Thus, the current study aimed to characterize the postharvest storage of cauliflower hybrids Snow Mystique and Graffiti kept at room temperature corresponding to an air temperature of 20 ± 2oC and a relative humidity (RH of 75%. Evaluations were made every three days during a period of 12 days of storage. The parameters studied were percentage of weight loss in fresh weight terms, firmness of stem, soluble solids, pH and measurable acidity. By evaluating the results, it was concluded that the cauliflower is not supposed to be stored at an air temperature of 20 ± 2oC and a 75% RH for more than three days, since the inflorescence presented a high water loss through the transpiration process under the environmental conditions in study.

  10. Human enteric pathogen internalization by root uptake into food crops

    Science.gov (United States)

    With an increasing number of outbreaks and illnesses associated with pre-harvest contaminated produce, understanding the potential and mechanisms of produce contamination by enteric pathogens can aid in the development of preventative measures and post-harvest processing to reduce microbial populati...

  11. Post-Harvest Deterioration of Cassava and its Control Using Extracts of Azadirachta Indica and Aframomum Melegueta

    Directory of Open Access Journals (Sweden)

    R. N. Okigbo

    2009-01-01

    Full Text Available Post-harvest deterioration is the most important cause of loss in cassava production and this is mainly as a result of microbial invasion of the tubers. This research was therefore carried out to identify and control the organisms responsible for post-harvest deterioration of cassava tubers. Ethanolic and water extractions of Azadirachta Indica (A. Juss leaves and Aframomum melegueta (Schumann seeds were used as antifungal agents and the susceptibility of four of the isolated pathogenic fungi to them was observed in culture. The tested organisms were Aspergillus niger Van Tiegh, Botryodiplodia theobromae Pat, Fusarium solani (Mart. Sacc and Penicillium oxalicum Currie and Thom. All tested organisms showed different degrees of inhibitions by the extracts with A. niger being the most inhibited by ethanolic extraction of A. melegueta. The overall result showed that A. indica was more active on the organisms though it’s effects and that of A. melegueta were not significantly different (P>0.05.

  12. Report of postharvest rot of kiwifruit in Korea caused by Sclerotinia sclerotiorum.

    Science.gov (United States)

    Lee, Jung Han; Kwon, Young Ho; Kwack, Yong-Bum; Kwak, Youn-Sig

    2015-08-03

    In May 2014, sclerotinia rot symptoms caused by Sclerotinia sclerotiorum were observed on stored kiwifruit in Jinju, South Korea. The symptoms appeared as soft, water-soaked lesions on fruit covered with a white mycelium. The morphological characteristics and the internal transcribed spacer sequences of rRNA of the pathogen isolated from the sclerotinia rot showed it to be S. sclerotiorum. This was confirmed by performing a pathogenicity test with pure cultures of S. sclerotiorum and by reisolating S. sclerotiorum from artificially inoculated kiwifruits. Our results should help promote a better understanding of the diseases that affect kiwifruit and improve practices for postharvest disease control in the kiwifruit industry. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Inoculum Potential of Fusarium spp. Relates to Tillage and Straw Management in Norwegian Fields of Spring Oats

    Science.gov (United States)

    Hofgaard, Ingerd S.; Seehusen, Till; Aamot, Heidi U.; Riley, Hugh; Razzaghian, Jafar; Le, Vinh H.; Hjelkrem, Anne-Grete R.; Dill-Macky, Ruth; Brodal, Guro

    2016-01-01

    The increased occurrence of Fusarium-mycotoxins in Norwegian cereals over the last decade, is thought to be caused by increased inoculum resulting from more cereal residues at the soil surface as a result of reduced tillage practices. In addition, weather conditions have increasingly promoted inoculum development and infection by Fusarium species. The objective of this work was to elucidate the influence of different tillage regimes (autumn plowing; autumn harrowing; spring plowing; spring harrowing) on the inoculum potential (IP) and dispersal of Fusarium spp. in spring oats. Tillage trials were conducted at two different locations in southeast Norway from 2010 to 2012. Oat residues from the previous year’s crop were collected within a week after sowing for evaluation. IP was calculated as the percentage of residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. Fusarium avenaceum and F. graminearum were the most common Fusarium species recovered from oat residues. The IP of Fusarium spp. was significantly lower in plowed plots compared to those that were harrowed. Plowing in either the autumn or spring resulted in a low IP. Harrowing in autumn was more effective in reducing IP than the spring harrowing, and IP levels for the spring harrowed treatments were generally higher than all other tillage treatments examined. Surprisingly low levels of F. langsethiae were detected in the residues, although this species is a common pathogen of oat in Norway. The percentage of the residues infested with F. avenaceum, F. graminearum, F. culmorum, and F. langsethiae generally related to the quantity of DNA of the respective Fusarium species determined using quantitative PCR (qPCR). Fusarium dispersal, quantified by qPCR analysis of spore trap samples collected at and after heading, generally corresponded to the IP. Fusarium dispersal was also observed to increase after rainy periods. Our findings are in line with the

  14. Inoculum potential of Fusarium spp. relates to tillage and straw management in Norwegian fields of spring oats

    Directory of Open Access Journals (Sweden)

    Ingerd Skow Hofgaard

    2016-04-01

    Full Text Available The increased occurrence of Fusarium-mycotoxins in Norwegian cereals over the last decade, is thought to be caused by increased inoculum resulting from more cereal residues at the soil surface as a result of reduced tillage practices. In addition, weather conditions have increasingly promoted inoculum development and infection by Fusarium species. The objective of this work was to elucidate the influence of different tillage regimes (autumn plowing; autumn harrowing; spring plowing; spring harrowing on the inoculum potential (IP and dispersal of Fusarium spp. in spring oats. Tillage trials were conducted at two different locations in southeast Norway from 2010 to 2012. Oat residues from the previous year’s crop were collected within a week after sowing for evaluation. IP was calculated as the percentage of residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. F. avenaceum and F. graminearum were the most common Fusarium species recovered from oat residues. The IP of Fusarium spp. was significantly lower in plowed plots compared to those that were harrowed. Plowing in either the autumn or spring resulted in a low IP. Harrowing in autumn was more effective in reducing IP than the spring harrowing, and IP levels for the spring harrowed treatments were generally higher than all other tillage treatments examined. Surprisingly low levels of F. langsethiae were detected in the residues, although this species is a common pathogen of oat in Norway. The percentage of the residues infested with F. avenaceum, F. graminearum, F. culmorum and F. langsethiae generally related to the quantity of DNA of the respective Fusarium species determined using qPCR. Fusarium dispersal, quantified by quantitative PCR analysis of spore trap samples collected at and after heading, generally corresponded to IP. Fusarium dispersal was also observed to increase after rainy periods. Our findings are in line with the

  15. Retention of Viability of Salmonella in Sucrose as Affected by Type of Inoculum, Water Activity, and Storage Temperature.

    Science.gov (United States)

    Beuchat, Larry R; Mann, David A; Kelly, Christine A; Ortega, Ynes R

    2017-09-01

    Outbreaks of salmonellosis have been associated with consumption of high-sugar, low-water activity (a w ) foods. The study reported here was focused on determining the effect of storage temperature (5 and 25°C) on survival of initially high and low levels of Salmonella in dry-inoculated sucrose (a w 0.26 ± 0.01 to 0.54 ± 0.01) and wet-inoculated sucrose (a w 0.24 ± 0.01 to 0.44 ± 0.04) over a 52-week period. With the exception of dry-inoculated sucrose at a w 0.26, Salmonella survived for 52 weeks in dry- and wet-inoculated sucrose stored at 5 and 25°C. Retention of viability was clearly favored in sucrose stored at 5°C compared with 25°C, regardless of level or type of inoculum or a w . Survival at 5°C was not affected by a w . Initial high-inoculum counts of 5.18 and 5.25 log CFU/g of dry-inoculated sucrose (a w 0.26 and 0.54, respectively) stored for 52 weeks at 5°C decreased by 0.56 and 0.53 log CFU/g; counts decreased by >4.18 and >4.25 log CFU/g in samples stored at 25°C. Inactivation rates in wet-inoculated sucrose were similar to those in dry-inoculated sucrose; however, a trend toward higher persistence of Salmonella in dry- versus wet-inoculated sucrose suggests there was a higher proportion of cells in the wet inoculum with low tolerance to osmotic stress. Survival patterns were similar in sucrose initially containing a low level of Salmonella (2.26 to 2.91 log CFU/g). The pathogen was recovered from low-inoculated sucrose stored at 5°C for 52 weeks regardless of type of inoculum or a w and from dry-inoculated sucrose (a w 0.54) and wet-inoculated sucrose (a w 0.24) stored at 25°C for 12 and 26 weeks, respectively. Results emphasize the importance of preventing contamination of sucrose intended for use as an ingredient in foods not subjected to a treatment that would be lethal to Salmonella.

  16. Arthropods vector grapevine trunk disease pathogens.

    Science.gov (United States)

    Moyo, P; Allsopp, E; Roets, F; Mostert, L; Halleen, F

    2014-10-01

    Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases.

  17. Postharvest Practices for Organically Grown Products

    Directory of Open Access Journals (Sweden)

    Ilić Zoran S.

    2018-03-01

    Full Text Available Quality of produce cannot be improved after harvest, only maintained. Postharvest handling depends on the specific conditions of production, season, method of handling, and distance to market. Under organic production, growers harvest and market their produce at or near the peak ripeness more commonly than in many conventional systems. Organic production often includes more specialty varieties whose shelf life and shipping traits are reduced or even inherently poor. Harvesting and handling techniques that minimize injury to the commodity, as well as increased care with field and packinghouse sanitation, (chlorine, ozone, calcium hypochlorite, sodium hypochlorite and chlorine dioxide, acetic acid, peroxyacetic acid, vinegar, ethyl alcohol, hydrogen peroxide, etc. during postharvest processes are vital components of a postharvest management plan for organic products. Sodium carbonate, sodium bicarbonate, and physical treatments such as heat treatments (as hot water treatment or dips, short hot water rinsing and brushing or hot air can significantly lower the disease pressure on the harvested commodities. These sanitation practices are very easy to implement in the organic food production chain. They start in the field and continue during harvesting, sorting, packing, and transportation and continue even in the consumer’s home. All those treatments reduce rot development, provide quarantine security, and preserve fruit quality during cold storage and shelf life. In addition, the use chitosan, propolis, methyl jasmonate, essential oils, carnuba wax, biocontrol agents and modified atmosphere packaging can also reduce decay development during prolonged storage. All these treatments can be applied alone or in combination with each other in order to improve decay control after harvest and provide a healthy and safe product to the consumer. The aim of this chapter is to shed more light on the latest information on permitted treatments for organic

  18. Understanding the Physiology of Postharvest Needle Abscission in Balsam Fir

    OpenAIRE

    Lada, Rajasekaran R.; MacDonald, Mason T.

    2015-01-01

    Balsam fir (Abies balsamea) trees are commonly used as a specialty horticultural species for Christmas trees and associated greenery in eastern Canada and United States. Postharvest needle abscission has always been a problem, but is becoming an even bigger challenge in recent years presumably due to increased autumn temperatures and earlier harvesting practices. An increased understanding of postharvest abscission physiology in balsam fir may benefit the Christmas tree industry while simulta...

  19. Epizootic rabbit enteropathy inoculum (TEC4): antibiograms and antibiotic fractionation.

    Science.gov (United States)

    Huybens, Nathalie; Houeix, Julien; Licois, Dominique; Mainil, Jacques; Marlier, Didier

    2011-01-01

    Epizootic rabbit enteropathy (ERE) emerged and spread in Europe within the last 13 years causing major economical loss. The aims of the study was to evaluate antibiograms of TEC4, an inoculum composed of an extract of intestinal content of affected rabbits, and to test the potential of different antibiotic-based TEC4 fractions to reproduce the disease. Twenty nine different antibiotic discs were incubated for determining bacteria resistance. In a complementary study, nine tubes of liquid medium were inoculated with TEC4, incubated and added individually with amoxicillin/clavulanic acid, bacitracin, ceftiofur, doxycycline, novobiocin, streptomycyin, tylosin, vancomycin and 0.9% saline solution as control. The content of each tube was washed by centrifugation and suspended in saline. The three most effective antibiotics are florfenicol, amoxycillin/clavulanic acid and tylosin. A high concentration of Clostridium sordelli and Bacillus firmus were isolated in all fractions. Species never cultured from TEC4 were identified as Fusobacterium necrogenes (in vancomycin fraction), Cellulomonas sp (in novobiocin fraction) and Bacteroides distasonis (in doxycycline fraction). The ERE was reproduced when bacitracin, doxycycline and 0.9% fractions were inoculated. Rabbits showed ERE clinical signs with the specific drop in daily weight gain.

  20. Towards a universal microbial inoculum for dissolved organic carbon degradation experiments

    Science.gov (United States)

    Pastor, Ada; Catalán, Núria; Gutiérrez, Carmen; Nagar, Nupur; Casas-Ruiz, Joan P.; Obrador, Biel; von Schiller, Daniel; Sabater, Sergi; Petrovic, Mira; Borrego, Carles M.; Marcé, Rafael

    2017-04-01

    Dissolved organic carbon (DOC) is the largest biologically available pool of organic carbon in aquatic ecosystems and its degradation along the land-to-ocean continuum has implications for carbon cycling from local to global scales. DOC biodegradability is usually assessed by incubating filtered water inoculated with native microbial assemblages in the laboratory. However, the use of a native inoculum from several freshwaters, without having a microbial-tailored design, hampers our ability to tease apart the relative contribution of the factors driving DOC degradation from the effects of local microbial communities. The use of a standard microbial inoculum would allow researchers to disentangle the drivers of DOC degradation from the metabolic capabilities of microbial communities operating in situ. With this purpose, we designed a bacterial inoculum to be used in experiments of DOC degradation in freshwater habitats. The inoculum is composed of six bacterial strains that easily grow under laboratory conditions, possess a versatile metabolism and are able to grow under both aerobic and anaerobic conditions. The mixed inoculum showed higher DOC degradation rates than those from their isolated bacterial components and the consumption of organic substrates was consistently replicated. Moreover, DOC degradation rates obtained using the designed inoculum were responsive across a wide range of natural water types differing in DOC concentration and composition. Overall, our results show the potential of the designed inoculum as a tool to discriminate between the effects of environmental drivers and intrinsic properties of DOC on degradation dynamics.

  1. Effects of postharvest handling conditions on internalization and growth of Salmonella enterica in tomatoes.

    Science.gov (United States)

    Zhou, Bin; Luo, Yaguang; Nou, Xiangwu; Yang, Yang; Wu, Yunpeng; Wang, Qin

    2014-03-01

    Salmonella internalization in tomatoes during postharvest handling is a major food safety concern. This study was conducted to determine the effect of immersion time, immersion depth, and temperature differential between bacterial suspension and tomato pulp on the internalization of Salmonella enterica in tomato fruits. The effect of storage temperature and duration on the survival and growth of internalized Salmonella cells was also evaluated. Overall, immersion time significantly affected the incidence and extent of S. enterica internalization (P internalization. The depth of Salmonella internalization in tomato tissues also increased with increasing immersion time. Immersion time also significantly influenced the degree to which the temperature differential affected Salmonella internalization. With an immersion time of 2 min, the temperature differential had no significant effect on Salmonella internalization (P = 0.2536). However, with an immersion time of 15 min, a significantly larger Salmonella population became internalized in tomatoes immersed in solutions with a -30°F (-16.7°C) temperature differential. Internalized S. enterica cells persisted in the core tissues during 14 days of storage. Strain type and storage duration significantly affected (P internalized Salmonella recovered, but storage temperatures of 55 to 70°F (12.8 to 21.1°C) did not (P > 0.05). These findings indicate the importance of preventing pathogen internalization during postharvest handling.

  2. Inoculum and zeolite synergistic effect on anaerobic digestion of poultry manure

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Kougias, Panagiotis; Zaganas, Ioannis D.

    2014-01-01

    zeolite dosages on the mesophilic AD of poultry manure inoculated with a non-acclimatised to ammonia inoculum (dairy manure) was investigated. Additionally, a comparative analysis was performed between the data extracted from this study and the results of a previous study which has been conducted under...... the same experimental conditions but with the use of ammonia acclimatised inoculum (swine manure). At 5 and 10 g zeolite L−1, the methane yield of poultry manure was 43.4% and 80.3% higher compared with the experimental set without zeolite addition. However, the ammonia non-acclimatised inoculum...... was not efficient in digesting poultry manure even in the presence of 10 g zeolite L−1, due to low methane production (only 39%) compared to the maximum theoretical yield. Finally, ammonia acclimatised inoculum and zeolite have demonstrated a possible “synergistic effect” which led to a more efficient AD of poultry...

  3. Inoculum of arbuscular mycorrhizal fungi for production systems: science meets business

    Czech Academy of Sciences Publication Activity Database

    Gianinazzi, S.; Vosátka, Miroslav

    2004-01-01

    Roč. 82, - (2004), s. 1264-1271 ISSN 0008-4026 Institutional research plan: CEZ:AV0Z6005908 Keywords : Inoculum production * mycorrhiza applications Subject RIV: EF - Botanics Impact factor: 1.194, year: 2004

  4. A test system to quantify inoculum in runoff from Phytophthora ramorum-infected plant roots

    Science.gov (United States)

    Nina. Shishkoff

    2010-01-01

    Foliar hosts of Phytophthora ramorum are often susceptible to root infection, but the epidemiological significance of such infections is unknown. We used a standardized test system to study inoculum in runoff from root-infected Viburnum tinus cuttings.

  5. Inoculum density of Glomus mosseae and growth of onion plants in unsterilized bituminous coal spoil

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.G.

    1988-01-01

    The effect of inoculum, density (number of vesicular-arbuscular mycorrhizal (VAM) propagules g/sup -1/ of inoculum) on the growth of onions (Allium cepa L.) infected by Glomus mosseae (Nicol and Gerd). Gerdemann and Trappe, Comb nov in unsterilized coal spoil containing indigenous VAM fungi, including G. mosseae, was investigated. The amount of onion roots converted to mycorrhizas by inoculant fungus, estimated by a gridline intersect method, increased with inoculum density (..gamma..0.62, P0.05) until a plateau was reached. Onion growth responses also increased significantly (P<0.05) with the amount of VAM inoculum present in the coal spoil. The initial linear relationship between inoculum propagules (MPN estimates), percent colonization of onion roots and onion shoot dry weight became quadratic as the number of infection propagules increased. VAM infection had no significant effect on root:shoot ratios. Similarly there was no significant interaction (P>0.05) between the inoculum density, VAM-colonized root mass and the onion root:shoot fresh weight ratios. The amount of the windswept bituminous coal spoil bound to VAM (presumably because of VAM external hyphae) also increased as inoculum density increased (..gamma..0.63, P<0.05). There was a stronger correlation (ga0.85, P<0.05) between the amount of spoil adhered per plant and the root fresh wt plant/sup -1/ indicating that root effects were primarily responsible for increasing spoil adherence. There were negative correlations (P<0.05) between root fresh wt plant/sup -1/ (..gamma..-0.68), inoculum density (..gamma..-0.589), percent root elngth infected (..gamma..-0.73) and the amount of spoil adhered g/sup -1/ root fresh wt. The possible exploitation of VAM in revegetation of bituminous coal spoil is discussed. 25 refs., 2 tabs.

  6. Liming and postharvest quality of carambola fruits

    Directory of Open Access Journals (Sweden)

    Renato de Mello Prado

    2005-09-01

    Full Text Available To determine the effects of lime application on the postharvest quality of carambola fruit, an experiment with carambola trees cultivated on an acid soil was conducted at the Bebedouro, São Paulo, Brazil. The trees were treated with increasing doses of lime during the pre-planting period. Liming led to a increase in calcium concentration of carambola leaves and fruits. Adequate nutrition of the plant with calcium improved post-harvest fruit quality, permitting a longer (~ 2 days period of storage under ambient conditions.Tendo como objetivo avaliar os efeitos da aplicação de doses crescentes de calcário ao solo, na qualidade de frutos de caramboleira pela avaliação das alterações físico-químicas dos frutos após a colheita, foi instalado um experimento em Bebedouro-SP,Brasil, sobre um Latossolo Vermelho distrófico, ácido. Os tratamentos foram doses crescentes de calcário, em pré-plantio, como segue: D0 = zero; D1 = metade da dose; D2 = a dose; D3 = 1,5 vez a dose; e D4 = 2 vezes a dose para elevar V= 70%. No florescimento da caramboleira, avaliou-se o teor de cálcio na folha. Após a colheita dos frutos, determinou-se o teor de cálcio na polpa, o peso dos frutos, diâmetro transversal, comprimento, peso da polpa, % de polpa, ºBrix, acidez titulável e Ratio dos frutos. Diariamente, durante sete dias de armazenamento em condições ambiente, determinou-se a perda de massa fresca e a firmeza dos frutos. A calagem proporcionou um aumentou linear de cálcio nas folhas e nos frutos da caramboleira. A nutrição adequada da planta com cálcio melhorou a qualidade dos frutos pós-colheita, permitindo um período de armazenamento mais longo (~ 2 days, em condições ambiente.

  7. DIFFERENT SOURCES OF INOCULUM TO THE BOKASHI PROVIDES DISTINCT EFFECTS ON THE SOIL QUALITY

    Directory of Open Access Journals (Sweden)

    Juliana Cristina Scotton

    2017-10-01

    Full Text Available Bokashi soil conditioner aims to assist in the resilience of natural microbiota and its associated functions. Currently, there are several formulations of this conditioner, however, little is known about the influence of the sources of inoculum on the quality of the same. This study objective was to evaluate the effects of different sources of bokashi inoculum on microbiological and physical attributes of the soil. The experiment was conducted in tubes designated as microcosms, incubated at 24 °C for 32 days, with 4 treatments and 10 replications: C - control; SI - bokashi bran without inoculum; IN1 - bokashi with forest inoculum; IN2 - bokashi with consortium inoculum. The microbiological parameters of colony forming units of fungi and bacteria, microbial biomass carbon, basal soil respiration, metabolic and microbial quotient were evaluated. Among the physical parameters evaluated were dispersed clay, geometric mean diameter and organic carbon. The data were submitted to ANOVA and the measurements compared by the Tukey test at 5%. The fungal density was significantly higher for SI and IN1, as compared to the other treatments. In regards to the bacteria, there was an increase for IN1, in comparison with the control. The IN1 treatment demonstrated higher microbial activity and higher C uptake in the soil. Regarding the physical attributes, there was greater clay dispersion for IN2 and greater GMD for C. The bokashi formulation with forest inoculum and cropping field provides higher microbiological quality to the soil under controlled conditions.

  8. Improving Postharvest Storage of Apple Cv.

    Directory of Open Access Journals (Sweden)

    H. Etemadi Nasab

    2013-06-01

    Full Text Available Apple is one of the important fruit in Iran. according to respiration and ethylene production behaviors, apple classified as a climacteric fruit. Therefore, any treatments, which can inhibit or prevent the action of ethylene, they can increase the postharvest life of horticultural production. 1-methylcyclopropane (1-MCP is one of the chemical which is environmental save and use as a very small concentrations. In this experiment, the effects of 1-MCP at concentrations of 0 (as a control, 0.25, 0.5, 0.75 and 1 µl.l-1 were used in apple cv. "Golab Kohanz", a land race fruits which is cultivated from long times ago in Iran. After the 1-MCP treatment, they were moved to cold room at 2 ºC and RH of ca 90% for 60 days. Samples were removed from the cold room and analysis for physicochemical characteristics. "Golab Kohanz" apples treated with 1-MCP showed improved fruit firmness, titratable acidity (TA, and total soluble solid after 147 days at 2ºC , compared to the control non-treated fruits. Also, treatment with 1-MCP significantly reduced the incidence of superficial scald in "Golab Kohanze". In general, 1-MCP-treated apples delay ripening during storing in cold room and increased shelf life. Overall, the results indicate that 1-MCP has tremendous potential for maintaining apple quality during storage and post storage.

  9. Effect of seasonal abiotic conditions and field margin habitat on the activity of Pandora neoaphidis inoculum on soil.

    Science.gov (United States)

    Baverstock, J; Clark, S J; Pell, J K

    2008-03-01

    The ability of the aphid pathogenic fungus Pandora neoaphidis to remain active in the absence of a resting stage through a combination of continuous infection and as conidia deposited on soil was assessed alongside the potential for planted field margins to act as a refuge for the fungus. P. neoaphidis was able to infect the pea aphid, Acyrthosiphon pisum, when maintained under controlled conditions that simulated those that occur seasonally in the UK. Although there was a significant inverse relationship between temperature and time-to-kill, with death occurring after 4.2, 6.9 and 13.6 days when maintained under fluctuating summer, autumn and winter temperatures, respectively, there were no additional statistically significant effects of photoperiod. The activity of inoculum on soil was indirectly assessed by baiting with A. pisum. Under controlled conditions P. neoaphidis remained active on soil and was able to infect aphids for up to 80 days. However, the percentage of aphids that became infected decreased from 76% on day 1 to 11% on day 80. Whereas there was little difference in the activity of conidia that had been maintained at 4 degrees C and 10 degrees C, activity at 18 degrees C was considerably reduced. Under field conditions the activity of inoculum was strongly influenced by season. On day 49 there was little or no activity during spring, summer or winter. However, during autumn a mean proportion of 0.08 aphids still became infected with P. neoaphidis. Margin type did not affect the activity of conidia nor was there a difference in activity between blocks that had regenerated naturally and those that had been planted. These results suggest that P. neoaphidis can infect aphids and remain active on soil under the abiotic conditions that occur seasonally in the UK and that this fungus may be able to persist annually without a resting stage.

  10. Understanding the physiology of postharvest needle abscission in balsam fir

    Directory of Open Access Journals (Sweden)

    Mason Thane Macdonald

    2015-11-01

    Full Text Available Balsam fir (Abies balsamea trees are commonly used as a specialty horticultural species for Christmas trees and associated greenery in eastern Canada and United States. Postharvest needle abscission has always been a problem, but is becoming an even bigger challenge in recent years presumably due to increased autumn temperatures and earlier harvesting practices. An increased understanding of postharvest abscission physiology in balsam fir may benefit the Christmas tree industry while simultaneously advancing our knowledge in senescence and abscission of conifers in general. Our paper describes the dynamics of needle abscission in balsam fir while identifying key factors that modify abscission patterns. Concepts such as genotypic abscission resistance, nutrition, environmental factors, and postharvest changes in water conductance and hormone evolution are discussed as they relate to our understanding of the balsam fir abscission physiology. Our paper ultimately proposes a pathway for needle abscission via ethylene and also suggests other potential alternative pathways based on our current understanding.

  11. Effect of chitosan coatings on postharvest green asparagus quality.

    Science.gov (United States)

    Qiu, Miao; Jiang, Hengjun; Ren, Gerui; Huang, Jianying; Wang, Xiangyang

    2013-02-15

    Fresh postharvest green asparagus rapidly deteriorate due to its high respiration rate. The main benefits of edible active coatings are their edible characteristics, biodegradability and increase in food safety. In this study, the quality of the edible coatings based on 0.50%, 0.25% high-molecular weight chitosan (H-chitosan), and 0.50%, 0.25% low-molecular weight chitosan (L-chitosan) on postharvest green asparagus was investigated. On the basis of the results obtained, 0.25% H-chitosan and 0.50% L-chitosan treatments ensured lower color variation, less weight loss and less ascorbic acid, decrease presenting better quality of asparagus than other concentrations of chitosan treatments and the control during the cold storage, and prolonging a shelf life of postharvest green asparagus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Impact of Cropping Systems, Soil Inoculum, and Plant Species Identity on Soil Bacterial Community Structure.

    Science.gov (United States)

    Ishaq, Suzanne L; Johnson, Stephen P; Miller, Zach J; Lehnhoff, Erik A; Olivo, Sarah; Yeoman, Carl J; Menalled, Fabian D

    2017-02-01

    Farming practices affect the soil microbial community, which in turn impacts crop growth and crop-weed interactions. This study assessed the modification of soil bacterial community structure by organic or conventional cropping systems, weed species identity [Amaranthus retroflexus L. (redroot pigweed) or Avena fatua L. (wild oat)], and living or sterilized inoculum. Soil from eight paired USDA-certified organic and conventional farms in north-central Montana was used as living or autoclave-sterilized inoculant into steam-pasteurized potting soil, planted with Am. retroflexus or Av. fatua and grown for two consecutive 8-week periods to condition soil nutrients and biota. Subsequently, the V3-V4 regions of the microbial 16S rRNA gene were sequenced by Illumina MiSeq. Treatments clustered significantly, with living or sterilized inoculum being the strongest delineating factor, followed by organic or conventional cropping system, then individual farm. Living inoculum-treated soil had greater species richness and was more diverse than sterile inoculum-treated soil (observed OTUs, Chao, inverse Simpson, Shannon, P soil contained more Chloroflexi and Acidobacteria, while the sterile inoculum soil had more Bacteroidetes, Firmicutes, Gemmatimonadetes, and Verrucomicrobia. Organically farmed inoculum-treated soil had greater species richness, more diversity (observed OTUs, Chao, Shannon, P soil. Cyanobacteria were higher in pots growing Am. retroflexus, regardless of inoculum type, for three of the four organic farms. Results highlight the potential of cropping systems and species identity to modify soil bacterial communities, subsequently modifying plant growth and crop-weed competition.

  13. Postharvest quality of essential oil treated roses

    Directory of Open Access Journals (Sweden)

    Guilherme Mariano Manfredini

    2017-07-01

    Full Text Available The loss of commercial quality during storage and transportation of roses is one of the factors that reflect on production costs, leading producers to preventively apply harmful chemicals, mainly to hamper Botrytis cinerea development and reduce further losses. An alternative to increase flower longevity without contaminating the environment with harmful chemicals is the use of natural products, such as essential oils, which have fungistatic and insecticide properties, as well as low toxicity. The objective of this study was to evaluate the effect of essential oils on the vase life of Rosa cv. Avalanche: 12 treatments were tested, resulting from the combination of 5 types of essential oils plus the control in two cold storage periods (2 to 6 days at 1 °C, 90-95% RH. The essential oils tested were eucalyptus, cinnamon, lemongrass and peppermint (1%, clove (0.1%, plus a control with distilled water. Application was made by spraying the flower buds. After storage at low temperatures, the flower stems were kept in a room (16 °C, 70% RH during 10 days for evaluation. Flower stems stored for 2 days in a cold chamber showed better means for darkening, turgor and bent neck, as well as a lower weight loss by the stems. The application of lemongrass essential oil at 1% caused burns on the petals, compromising quality and pot life. The essential oils of peppermint and eucalyptus allowed flower quality maintenance until the 10th day of evaluation. It is possible to conclude that post-harvest spraying with peppermint or eucalyptus essential oil at 1%, combined with cold storage for 2 days, provided greater longevity and quality for cv. Avalanche roses.

  14. PROPOLIS EXTRACT IN POSTHARVEST CONSERVATION BANANA ' PRATA'

    Directory of Open Access Journals (Sweden)

    FLÁVIA REGINA PASSOS

    2016-01-01

    Full Text Available ABSTRACT In the present work were evaluated the effects of propolis coatings of various botanical sources on quality traits of bananas cv. Prata (Musa sapientum L. stored at room temperature. ´Prata´ bananas were selected and submitted to five postharvest treatments: four coatings applied by immersion in propolis extracts at a concentration of 2.5% (w/v and a control (without coating. Propolis extracts were applied as 1 a wild type aqueous propolis extract, 2 a wild type hydroalcoholic propolis extract, 3 a rosemary green type hydroalcoholic propolis extract and 4 a red type hydroalcoholic propolis extract. The bananas were evaluated at three-day intervals along 12 days for fresh weight losses, flesh firmness, soluble solids (SS, titratable acidity (TA, the ratio SS/TA and pH. Sensory analyses were performed after three and six days of storage by 55 not trained panelists designed for acceptability. At the end of the twelve-day storage period, bananas coated either with the rosemary green hydroalcoholic extract or with the aqueous extract presented lower fresh weight losses in comparison to the bananas of the control treatment. No differences were determined in relation to flesh firmness and along the storage period TA values decreased and pH values increased in bananas of all treatments. SS contents increased towards the end of the storage period that, consequently, contributed to increases in the SS/TA ratio. The most significant increase in SS/TA ratio was determined in bananas coated with the red type hydroalcoholic extract. Taste panelists did not detect significant differences amongst coated and not coated cv. Prata bananas up to six days of storage.

  15. Development of a robust, versatile, and scalable inoculum train for the production of a DNA vaccine.

    Science.gov (United States)

    Okonkowski, J; Kizer-Bentley, L; Listner, K; Robinson, D; Chartrain, M

    2005-01-01

    For many microbial fermentation processes, the inoculum train can have a substantial impact on process performance in terms of productivity, profitability, and process control. In general, it is understood that a well-characterized and flexible inoculum train is essential for future scale-up and implementation of the process in a pilot plant or manufacturing setting. A fermentation process utilizing E. coli DH5 for the production of plasmid DNA carrying the HIV gag gene for use as a vaccine is currently under development in our laboratory. As part of the development effort, we evaluated inoculum train schemes that incorporate one, two, or three stages. In addition, we investigated the effect of inoculum viable-cell concentrations, either thawed or actively growing, over a wide range (from 2.5 x 10(4) to 1.0 x 10(8) viable cells/mL or approximately 0.001% to 4% of final working volume). The various inoculum trains were evaluated in terms of final plasmid yield, process time, reproducibility, robustness, and feasibility at large scale. The results of these studies show that final plasmid yield remained in the desired range, despite the number of stages or inoculation viable-cell concentrations comprising the inoculum train. On the basis of these observations and because it established a large database, the first part of these investigations supports an exceptional flexibility in the design of scalable inoculum trains for this DNA vaccine process. This work also highlighted that a slightly higher level of process reproducibility, as measured by the time for the culture to reach mid-exponential growth, was observed when using actively growing versus frozen cells. It also demonstrated the existence of a viable-cell concentration threshold for the one-stage process, since we observed that inoculation of the production stage with very low amounts of viable cells from a frozen source could lead to increased process sensitivity to external factors such as variation in the

  16. Low doses of gamma radiation in the management of postharvest Lasiodiplodia theobromae in mangos

    Directory of Open Access Journals (Sweden)

    Alice Maria Gonçalves Santos

    2015-09-01

    Full Text Available The postharvest life of mango is limited by the development of pathogens, especially fungi that cause rot, among which stands out the Lasiodiplodia theobromae. Several control methods have been employed to minimize the damages caused by this fungus, chemical control can leave residues to man and nature; physical control by the use of gamma radiation in combination with modified atmosphere and cold storage. The use of gamma radiation helps to reduce the severity of the pathogen assist in the ripening process of fruits, even at low doses (0.25, 0.35 and 0.45 kGy chemical properties such as pH, soluble solids, acid ascorbic, titratable acidity and also the quality parameters of the pulp showed no damage that are ideal for trade and consumption of mangoes. This treatment can be extended for use in the management of diseases such as natural infections for penducular rot complex that has as one of L. theobroma pathogens involved.

  17. Evaluation of yeasts obtained from Antarctic soil samples as biocontrol agents for the management of postharvest diseases of apple (Malus × domestica).

    Science.gov (United States)

    Vero, Silvana; Garmendia, Gabriela; González, M Belén; Bentancur, Oscar; Wisniewski, Michael

    2013-03-01

    Psychrotrophic yeasts were isolated from Antarctic soils, selected based on their ability to grow in apple juice at low temperatures, and were evaluated as potential biocontrol agents for the management of postharvest diseases of apple during cold storage. Among the species recovered, an isolate of Leucosporidium scottii, designated At17, was identified as a good biocontrol agent for blue and gray mold of two apple cultivars. The selected isolate produced soluble and volatile antifungal substances that were inhibitory to apple pathogens. Siderophore production was also demonstrated, but it did not appear to play a role in pathogen inhibition. The selected yeast had the capacity to form a biofilm when grown in apple juice, which is considered an important attribute of postharvest antagonists to successfully colonize wounds and intact fruit surfaces. At17 was resistant to commonly used postharvest fungicides, so application of a combination of low-dose fungicide along with the biocontrol agent could be used as an integrated management practice. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  18. Potential of a new strain of Bacillus amyloliquefaciens BUZ-14 as a biocontrol agent of postharvest fruit diseases.

    Science.gov (United States)

    Calvo, H; Marco, P; Blanco, D; Oria, R; Venturini, M E

    2017-05-01

    The biocontrol potential of the Bacillus amyloliquefaciens strain BUZ-14 was tested against the main postharvest diseases of orange, apple, grape and stone fruit. After characterizing the temperature and pH growth curves of strain BUZ-14, its in vitro antifungal activity was determined against Botrytis cinerea, Monilinia fructicola, M. laxa, Penicillium digitatum, P. expansum and P. italicum. Subsequently, in vivo activity was tested against these pathogens by treating fruit with cells, endospores and cell-free supernatants. The in vitro results showed that BUZ-14 inhibited the growth of all the pathogens tested corresponding to the least susceptible species, P. italicum, and the most susceptible, M. laxa. In vivo tests corroborated these results as most of the treatments decreased the incidence of brown rot in stone fruit from 100% to 0%, establishing 10 7  CFU mL -1 as the minimum inhibitory concentration. For the Penicillium species a preventive treatment inhibited P. digitatum and P. italicum growth in oranges and reduced P. expansum incidence in apples from 100% to 20%. Finally, it has been demonstrated that BUZ-14 was able to survive and to control brown rot in peaches stored at cool temperatures, making it a very suitable biocontrol agent for application during the post-harvest storage and marketing of horticultural products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Effect of inoculum size on the antibiotic susceptibilities of β-lactamase positive isolates of Moraxella catarrhalis

    Directory of Open Access Journals (Sweden)

    J. Vraneš

    2005-08-01

    Full Text Available It is well known that bacteria producing β-lactamases in general show marked inoculum effect in susceptibility testing. The aim of this study is to determine the effect of inoculum size on the susceptibility of β-lactamase positive strains of M. catarrhalis to oral β-lactam and non β-lactam antibiotics. MICs of antibiotics were determined by a twofold microdilution technique with two different inoculum sizes were tested: 5x 105 CFU/ml -standard inoculum and 5 x107 CFU/ml -high inoculum. The highest increase (4-fold was observed with penicillins alone (amoxycillin and ampicillin or combined with inhibitor and ceftibuten, followed by older cephalosporins, erithromycine and chloramphenicol ( 2-fold. Tetracycline did not show a significant increase in MIC when a higher inoculum size was applied. In spite of the increase in MIC with high inoculum all strains were still susceptible to amoxycillin combined with clavulanate. MICs of cephalosporins were also below the resistance breakpoint for most of the strains at the higher inoculum. Based on that, we can conclude that therapeutic implications of the inoculum effect were not significant.These data suggest that high inocula should be used to determine MICs of ampicillin and amoxycillin for M. catarrhalis but that this precaution is unnecessary with the cephalosporins tested or with amoxycillin/clavulanate

  20. Improving the uptake of postharvest innovations by farmers: A ...

    African Journals Online (AJOL)

    The uptake of postharvest innovations by Cameroonian farmers is generally low. In an attempt to improve on the situation a new extension strategy was tested. Multiple participative activities were carried out with members of a rural organisation as a strategy to encourage them to adopt new cassava processing technologies ...

  1. Fungi associated with post-harvest deterioration of dried Clarias ...

    African Journals Online (AJOL)

    Fungi associated with post-harvest deterioration of dried Clarias gariepinus vended in some ... Journal of Aquatic Sciences ... Results revealed that fish samples from okpokpo market contained highest number (10) of fungal isolates while samples from Afaha ... Key Words: Mycoflora, isolation, fungi, Fusarium, C. gariepinus ...

  2. Postharvest quality of cut roses following electron-beam irradiation

    International Nuclear Information System (INIS)

    Chang, A.Y.; Gladon, R.J.; Gleason, M.L.; Parker, S.K.; Agnew, N.H.; Olson, D.G.

    1997-01-01

    Cut Rosa x hybrida L. 'Royalty' flowers were used to determine the efficacy of electron-beam irradiation for increasing postharvest quality and decreasing petal infection by Botrytis cinerea Pers. In an experiment for determining the injury threshold, roses received electron-beam irradiation of 0, 0.5, 1, 2, and 4 kGy. Irradiation dosages greater than or equal to 4 kGy caused necrosis on petal tissue and decreased postharvest life at 20 degrees C. In a second experiment to evaluate postharvest quality, roses were irradiated at 0, 0.25, 0.5, 0.75, and 1 kGy. Dosages of 0.25 and 0.5 kGy slowed the rate of flower bud opening for 2 days but did not decrease postharvest quality when compared with nonirradiated roses. Roses that received irradiation dosages of 0.75 and 1 kGy showed unacceptable quality. In a third experiment, roses that had or had not been inoculated with B. cinerea were irradiated at 0, 0.25, 0.5, and 0.75 kGy. Irradiation did not control B. cinerea populations, and rose quality decreased as dosage increased. In a fourth experiment to determine the effect of irradiation on B. cinerea, conidia on water-agar plates exposed to dosages less than or equal to 1, 2, and 4 kGy germinated at rates of approximately 90%, 33%, and 2%, respectively, within 24 h

  3. POST-HARVEST FUNGAL DISEASES OF PAWPAW ( CARICA ...

    African Journals Online (AJOL)

    Post-harvest fungal diseases of pawpaw (Carica papaya L.) fruits sold in Mile 3 Market, Port Harcourt were investigated bi-weekly for sixteen weeks using the Standard Blotter Method. The following fungi were isolated from the tissues of diseased fruits: Fusarium solani, Phoma carica-papaya Aspergillus flavus, Aspergillus ...

  4. Postharvest quality and safety maintenance of the physical ...

    African Journals Online (AJOL)

    Biodegradable edible coatings from Moringa oil(MO) and Neem oil (NO) was applied to carrot fruits in order to provide environmentally friendly, healthy treatments (with which to better preserve fresh fruit quality) and safety during postharvest storage at ambient temperature of 27± 3oC and relative humidity of 50-60% .

  5. Pre-harvest calcium sulfate application improves postharvest quality ...

    African Journals Online (AJOL)

    The quality of cut rose flowers at the postharvest stage is affected by pre-harvest conditions. The present study was conducted to examine the possible involvement of calcium sulfate (CaSO4) in regulation of rose flower senescence. Roses (Rosa hybrida L.) cultivars 'Cool Water' and 'Pretty Blinda', were treated with either ...

  6. Postharvest Ripening and Shelf Life of Mango (Mangifera indica L ...

    African Journals Online (AJOL)

    The mango (Mangifera indica L.) is a climacteric and highly perishable fruit that requires specialized postharvest handling to extend its storage life. The study was undertaken at Melkassa Agricultural Research Center (MARC) to evaluate the influence of 1-Methylcyclopropene (1-MCP) and polyethylene packaging (PP) on ...

  7. Postharvest problems of tomato production in Ghana - Field studies ...

    African Journals Online (AJOL)

    W.O Ellis, N.S. Olympio, E. Mensah, P. Adu-Amankwa, A. Y Tetteh ... To overcome this problem there is the need to develop simple, cost-effective and easily ... postharvest problems, preservation methods and marketing practices of farmers.

  8. Postharvest Losses in Africa: Analytical Review and Synthesis ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Across Africa, postharvest losses along the food chain from farm to fork jeopardize the food security of resource-poor farmers. ... Agent(e) responsable du CRDI ... La pleuropneumonie contagieuse des bovins est une maladie d'origine bactérienne qui a de graves conséquences sur l'économie et le commerce en Afrique ...

  9. Tomato farmers adoption level of postharvest value addition ...

    African Journals Online (AJOL)

    The study examined tomato farmers' adoption level of postharvest value addition technology and its constraints in Surulere Area of Oyo state. 160 tomato farmers were randomly selected and interviewed through structured interview schedule. Data obtained were subjected to descriptive and inferential statistics. Results ...

  10. Potential of predatory bacteria as biocontrol agents for foodborne and plant pathogens

    Science.gov (United States)

    Foodborne pathogens such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, Shigella are responsible for frequent occurrences of illnesses and mortality in humans and produce losses. Pre-harvest yield losses and post-harvest decay on minimally processed produce (fruits, vegetables...

  11. Determinants of Yam Postharvest Management in the Zabzugu District of Northern Ghana

    Directory of Open Access Journals (Sweden)

    Isaac Gershon Kodwo Ansah

    2016-01-01

    Full Text Available Postharvest loss reduction has received attention in many policy documents across nations to ensure global food security, particularly in developing countries. Many researchers have examined various options for reducing postharvest losses. We contribute our quota to this scientific discourse by using a different approach. We argue that the human element of managing postharvest loss is central and therefore poses the question of what are the characteristics of the farmer who manages postharvest losses better. We examine this question by using a cross section of yam farmers in the Zabzugu district in Northern Ghana and generate a proportional variable called postharvest management, which measures how effective a farmer works to reduce storage losses. We then use a fractional logistic regression model to examine the determinants of postharvest management. A significant result is that subsistence farmers manage postharvest losses better than commercial farmers. Characteristically, the farmer who effectively manages postharvest losses is a young, subsistence farmer, living in or close to a district capital with fewer household members, has attained formal education, and produces more yam. Efforts to reduce postharvest losses require the provision of access roads to remote towns or providing effective storage techniques and training on postharvest management practices.

  12. Effect of storage duration on frozen inoculum to be used for the in vitro gas production technique in rabbit

    Directory of Open Access Journals (Sweden)

    Antonino Nizza

    2010-01-01

    Full Text Available The present study aimed to investigate the effect of storage duration of frozen inoculum on fermentation parametersobtained with the in vitro gas production technique. Two non-predigested diets differing in chemical composition andespecially crude fibre content (low fibre diet: 13.8%; high-fibre diet: 22.6% were ground to pass a 1 mm screen andsubjected to fermentation with the same inoculum frozen for different periods: after 1 month (inoculum 1, after 2months (inoculum 2 and after 3 months (inoculum 3. The inoculum used was obtained from the caecal content of 75-day-old NZW rabbits. After defrosting, the caecal content was diluted with the medium 1:1 (V/V and squeezed throughsix layers of gauze to obtain the inoculum. The substrate affected several fermentation parameters. In particular, thehigh-fibre diet had lower potential and cumulative gas production (A = ml/g 220 vs 256; P vs 221; P acids (mmol/g 56.2 vs 49.8; P P values of degraded organic matter (62.4%, 62.7% and 62.7% respectively for inocula 1, 2 and 3 and similarproduction of VFA (54.0, 52.2 and 52.8 mmol/g, respectively for inocula 1, 2 and 3. This research showed it is possibleto use frozen inoculum for at least 3 months and in this time interval obtain the same parameters of in vitro fermentation.

  13. In Vitro Fermentation of Porcine Milk Oligosaccharides and Galacto-oligosaccharides Using Piglet Fecal Inoculum

    NARCIS (Netherlands)

    Difilippo, Elisabetta; Pan, Feipeng; Logtenberg, Madelon; Willems, Rianne; Braber, Saskia; Fink-Gremmels, Johanna; Schols, Henk A.; Gruppen, Harry

    2016-01-01

    In this study, the in vitro fermentation by piglet fecal inoculum of galacto-oligosaccharides (GOS) and porcine milk oligosaccharides (PMOs) was investigated to identify possible preferences for individual oligosaccharide structures by piglet microbiota. First, acidic PMOs and GOS with degrees of

  14. In Vitro Fermentation of Porcine Milk Oligosaccharides and Galacto-oligosaccharides Using Piglet Fecal Inoculum

    NARCIS (Netherlands)

    Difilippo, Elisabetta; Pan, Feipeng; Logtenberg, Madelon; Willems, Rianne H A M; Braber, Saskia; Fink-Gremmels, Johanna; Schols, Henk A; Gruppen, Harry

    In this study, the in vitro fermentation by piglet fecal inoculum of galacto-oligosaccharides (GOS) and porcine milk oligosaccharides (PMOs) was investigated to identify possible preferences for individual oligosaccharide structures by piglet microbiota. First, acidic PMOs and GOS with degrees of

  15. Effect of pH and inoculum size on pentachlorophenol degradation ...

    African Journals Online (AJOL)

    The success of this depends on finding strains able to degrade PCP in a changeable environment. The aim of this work was to study the influence of pH of the medium and the effect of inoculum size on pentachlorophenol degradation by Pseudomonas sp. A study of PCP degradation kinetics was performed to assess such ...

  16. The water kefir grain inoculum determines the characteristics of the resulting water kefir fermentation process.

    Science.gov (United States)

    Laureys, D; De Vuyst, L

    2017-03-01

    To investigate the influence of the water kefir grain inoculum on the characteristics of the water kefir fermentation process. Three water kefir fermentation processes were started with different water kefir grain inocula and followed as a function of time regarding microbial species diversity, community dynamics, substrate consumption profile and metabolite production course. The inoculum determined the water kefir grain growth, the viable counts on the grains, the time until total carbohydrate exhaustion, the final metabolite concentrations and the microbial species diversity. There were always 2-10 lactic acid bacterial cells for every yeast cell and the majority of these micro-organisms was always present on the grains. Lactobacillus paracasei, Lactobacillus hilgardii, Lactobacillus nagelii and Saccharomyces cerevisiae were always present and may be the key micro-organisms during water kefir fermentation. Low water kefir grain growth was associated with small grains with high viable counts of micro-organisms, fast fermentation and low pH values, and was not caused by the absence of exopolysaccharide-producing lactic acid bacteria. The water kefir grain inoculum influences the microbial species diversity and characteristics of the fermentation process. A select group of key micro-organisms was always present during fermentation. This study allows a rational selection of a water kefir grain inoculum. © 2016 The Society for Applied Microbiology.

  17. Inoculum and zeolite synergistic effect on anaerobic digestion of poultry manure.

    Science.gov (United States)

    Fotidis, Ioannis A; Kougias, Panagiotis G; Zaganas, Ioannis D; Kotsopoulos, Thomas A; Martzopoulos, Gerasimos G

    2014-01-01

    Poultry manure is an ammonia-rich substrate due to its high content of proteins and amino acids. Ammonia is the major inhibitor of anaerobic digestion (AD) process, affecting biogas production and causing great economic losses to the biogas plants. In this study, the effect of different natural zeolite dosages on the mesophilic AD of poultry manure inoculated with a non-acclimatized to ammonia inoculum (dairy manure) was investigated. Additionally, a comparative analysis was performed between the data extracted from this study and the results of a previous study, which has been conducted under the same experimental conditions but with the use of ammonia acclimatized inoculum (swine manure). At 5 and 10 g zeolite L(-1), the methane yield of poultry manure was 43.4% and 80.3% higher compared with the experimental set without zeolite addition. However, the ammonia non-acclimatized inoculum was not efficient in digesting poultry manure even in the presence of 10 g zeolite L(-1), due to low methane production (only 39%) compared with the maximum theoretical yield. Finally, ammonia acclimatized inoculum and zeolite have demonstrated a possible 'synergistic effect', which led to a more efficient AD of poultry manure. The results of this study could potentially been used by the biogas plant operators to efficiently digest poultry manure.

  18. Effects of inoculum potential on screening for resistance to Plasmodiophora brassicae in greenhouse trials

    Directory of Open Access Journals (Sweden)

    Józef Robak

    2013-12-01

    Full Text Available Several factors, including growth medium, inoculum density, and inoculum storage affected the reaction of resistant and susceptible Brassicas to Plasmodiophora brassicae in the greenhouse. A high level of disease was achieved using Peat-litte mix R and a commercial greenhouse mix. There was litte difference in disease incidence when spore suspensions were pipeted into planting holes or when seedlings were dipped into spore suspensions. Seedlings transplanted from sand or Petri dishes gave higher levels of disease than direct seeding. Two-year frozen storage of clubs reduced the inoculum potential to a level unable to define resistance. Inoculum levels of 103-7 spores per ml from fresh clubs, or 105-7 spores per ml from clubs frozen for 2 or 4 years, produced 90% club incidence of susceptible cauliflower and Chinese cabbage, A concentration of only 106-8 spores per ml from fresh clubs was required for maximum disease expression in a cauliflower line partially resistant to clubroot.

  19. Optimization of the production of mycorrhizal inoculum on substrate with organic fertilizer

    Directory of Open Access Journals (Sweden)

    Ieda R Coelho

    2014-12-01

    Full Text Available The system for production of inoculum of arbuscular mycorrhizal fungi (AMF using sand and vermiculite irrigated with nutrient solution is promising. However, organic amendments added to the substrate can stimulate sporulation of AMF and replace the nutrient solution. The aim of this study was to maximize the production of AMF (Acaulospora longula, Claroideoglomus etunicatum, Dentiscutata heterogama and Gigaspora albida using selected organic substrates (vermicompost, coir dust and Tropstrato together with sand and vermiculite. The production of spores varied among the tested AMF and according to the organic source added to the substrate. The vermicompost promoted higher sporulation of A. longula in relation to the other AMF and substrates. The Tropstrato® inhibited the sporulation of D. heterogama while the reproduction of C. etunicatum was not affected by the organic compounds. The inoculum of A. longula also showed a high number of infective propagules and promoted biomass accumulation in maize plants. The system of inoculum production using sand and vermiculite + 10% vermicompost favors the production of infective inoculum of A. longula with the fungus benefiting growth of corn plants.

  20. Increasing Biogas Production Rate from Cattle Manure Using Rumen Fluid as Inoculums

    Directory of Open Access Journals (Sweden)

    Budiyono Budiyono

    2013-10-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 In this study, rumen fluid of animal ruminant was used as inoculums to increase biogas production rate from cattle manure at mesophilic condition. A series of laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure (M was fed to each biodigester and mixed with rumen fluid (R and tap water (W in several ratio resulting six different M:W:R ratio contents i.e. 1:1:0; 1:0.75:0.25; 1:0.5:0.5; 1:0.25:0.75; and 1:0:1 (correspond to 0; 12.5; 25, 37.5; 50, and 100 % rumen, respectively and six different total solid (TS contents i.e. 2.6, 4.6, 6.2, 7.4, 9.2, 12.3, and 18.4 %. The operating temperatures were at room temperature. The results showed that the rumen fluid inoculated to biodigester significantly effected the biogas production. Rumen fluid inoculums caused biogas production rate and efficiency increase more than two times in compare to manure substrate without rumen fluid inoculums. The best performance for biogas production was the digester with rumen fluid and TS content in the range of 25-50 % and 7.4 and 9.2 %, respectively. These results suggest that, based on TS content effects to biogas yield, rumen fluid inoculums exhibit the similar effect with other inoculums. Increasing rumen content will also increase biogas production. Due to the optimum total solid (TS content for biogas production between 7-9 % (or correspond to more and less manure and total liquid 1:1, the rumen fluid content of 50 % will give the best performance for biogas production. The future work will be carried out to study the dynamics of biogas production if both the rumen fluid inoculums and manure are fed in the continuous system Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Doi: 10.12777/ijse.6.1.31-38 [How to cite this article: Budiyono, Widiasa, I.N., Johari, S. and Sunarso. (2014. Increasing Biogas

  1. Heat shock and salicylic acid on postharvest preservation of organic strawberries

    Directory of Open Access Journals (Sweden)

    Sidiane Coltro

    2014-06-01

    Full Text Available Heat shock and salicylic acid have been studied on shelf-life extension of fruits. The benefits of these techniques have been related to their effect on inducing physiological defense responses against the oxidative stress and pathogen development. The objective of this study was to evaluate the effect of heat shock and salicylic acid on the postharvest preservation and contents of total phenolics, anthocyanins, ascorbic acid, fresh weight loss and microbiological quality of organic strawberries cv. Dover. Strawberries produced organically and stored at 5 ºC were subjected to heat shock (45 ºC ± 3 ºC for 3 h, application of salicylic acid (soaking in 2.0 mmol L-1 solution, heat shock in combination with salicylic acid and control. After treatment, the fruits were packed and stored in a climatic chamber at 5 ºC ± 2 ºC. At 1, 7 and 14 days, the experimental units were removed from refrigeration and kept at room temperature of approximately 20 ºC for two days. There was no effect of treatments on fresh weight loss, incidence of pathogens or chemical variations in strawberry fruits during the storage period. In natural conditions, organically grown strawberries remained in good condition for sale up to seven days of storage in all treatments.

  2. Effect of alternative postharvest control treatments on the storability of 'Golden Delicious' apples.

    Science.gov (United States)

    Moscetti, Roberto; Carletti, Letizia; Monarca, Danilo; Cecchini, Massimo; Stella, Elisabetta; Massantini, Riccardo

    2013-08-30

    Apples are subject to a high degree of fungal diseases, but the use of synthetic fungicides has been questioned because of public safety concerns, social rejection, and the development of resistance in pathogens. Thus, development of new postharvest treatments against apple fungal pathogens is necessary. Most studies have reported their effectiveness, but not all report the effects on the quality and storability of the fruit. In this study, the effects of physical (hot water), chemical (quercetin) and biological (yeast antagonist) microfungal control on the quality of 'Golden Delicious' apple during storage at 2 ± 0.5 °C, and 90 ± 2% of relative humidity, for 2 months were investigated and compared. Heat-treated apples exhibited peel fruit damage (surface browning and internal breakdown disorders) and promoted ripening in the fruit. The quercetin caustic spray caused the development of peel chemical burn in all treated fruit. Both yeast antagonist and quercetin treatments did not affect the apple ripening process but stimulated an increase in ethylene production and in respiratory activity. The data indicated that the effects on quality and storability were dependent on the method of treatment used, and antagonistic yeast was the best microfungal control because of it did not cause any disorders or negative effects on apple quality during storage. © 2013 Society of Chemical Industry.

  3. Natural Variation in Banana Varieties Highlights the Role of Melatonin in Postharvest Ripening and Quality.

    Science.gov (United States)

    Hu, Wei; Yang, Hai; Tie, Weiwei; Yan, Yan; Ding, Zehong; Liu, Yang; Wu, Chunlai; Wang, Jiashui; Reiter, Russel J; Tan, Dun-Xian; Shi, Haitao; Xu, Biyu; Jin, Zhiqiang

    2017-11-22

    This study aimed to investigate the role of melatonin in postharvest ripening and quality in various banana varieties with contrasting ripening periods. During the postharvest life, endogenous melatonin showed similar performance with ethylene in connection to ripening. In comparison to ethylene, melatonin was more correlated with postharvest banana ripening. Exogenous application of melatonin resulted in a delay of postharvest banana ripening. Moreover, this effect is concentration-dependent, with 200 and 500 μM treatments more effective than the 50 μM treatment. Exogenous melatonin also led to elevated endogenous melatonin content, reduced ethylene production through regulation of the expression of MaACO1 and MaACS1, and delayed sharp changes of quality indices. Taken together, this study highlights that melatonin is an indicator for banana fruit ripening in various varieties, and the repression of ethylene biosynthesis and postharvest ripening by melatonin can be used for biological control of postharvest fruit ripening and quality.

  4. Biodegradation of PAHs in petroleum-contaminated soil using tamarind leaves as microbial inoculums

    Directory of Open Access Journals (Sweden)

    Kanchana Juntongjin

    2007-03-01

    Full Text Available Petroleum-contaminated soil contains various hazardous materials such as aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs. This study focused on PAHs since they are potentially toxic,mutagenic, and carcinogenic. Bioremediation of PAHs was carried out by adding tamarind leaf inoculums into petroleum-contaminated soil. Tamarind and other leguminous leaves have been reported to containedseveral PAH-degrading microorganisms. To minimize the amount of leaves added, the preparation of tamarind leaf inoculums was developed by incubating tamarind leaves with a sub-sample of contaminated soil for 49 days. After that, the efficiency of tamarind leaf inoculums was tested with two soil samplescollected from a navy dockyard and railway station in Samutprakarn and Bangkok, respectively. These soil samples had different levels of petroleum contamination. Bioaugmentation treatment was carried out bymixing contaminated soil with the inoculum at the ratio of 9:1. For navy dockyard soil, the concentration of phenanthrene was decreased gradually and reached the undetectable concentration within 56 days in theinoculated soil; meanwhile 70-80% of fluoranthene and pyrene were remained at the end of treatment. For railway station soil, which had lower petroleum contamination, PAH degradation was more rapid, forexample, the concentration of phenanthrene was below detection limit after 28 days. Besides PAHs, the amounts of several hydrocarbons were also reduced after treatment. At the same time, numerousphenanthrene-degrading bacteria, which were used as representatives of PAH degraders, could be observed in both inoculated soils. However, higher numbers of bacteria were found in railway station soil, whichcorresponded with the lower amount of PAHs and higher amount of soil nutrients. The results showed that inoculum prepared from tamarind leaves could be used to degrade PAHs as well as clean-up petroleum contaminated soil.

  5. Effect of inoculum-substrate ratio on acclimatization of pharmaceutical effluent in an anaerobic batch reactor.

    Science.gov (United States)

    Muruganandam, B; Saravanane, R; Lavanya, M; Sivacoumar, R

    2008-07-01

    Anaerobic treatment has gained tremendous success over the past two decades for treatment of industrial effluents. Over the past 30 years, the popularity of anaerobic wastewater treatment has increased as public utilities and industries have utilized its considerable benefits. Low biomass production, row nutrient requirements and the energy production in terms of methane yield are the significant advantages over aerobic treatment process. Due to the disadvantages reported in the earlier investigations, during the past decade, anaerobic biotechnology now seems to become a stable process technology in respect of generating a high quality effluent. The objective of the present experimental study was to compare the biodegradability of recalcitrant effluent (pharmaceutical effluent) for various inoculum-substrate ratios. The batch experiments were conducted over 6 months to get effect of ratio of inoculum-substrate on the acclimatization of pharmaceutical effluent. The tests were carried out in batch reactors, serum bottles, of volume 2000 mL and plastic canes of 10000 mL. Each inoculum was filled with a cow dung, sewage and phosphate buffer. The batch was made-up of diluted cow dung at various proportions of water and cow dung, i.e., 1:1 and 1:2 (one part of cow dung and one part of water by weight for 1:1). The bottles were incubated at ambient temperature (32 degrees C-35 degrees C). The bottles were closed tightly so that the anaerobic condition is maintained. The samples were collected and biodegradability was measured once in four days. The bottles were carefully stirred before gas measurement. The substrate was added to a mixture of inoculum and phosphate nutrients. The variations in pH, conductivity, alkalinity, COD, TS, TVS, VSS, and VFA were measured for batch process. The biogas productivity was calculated for various batches of inoculum-substrate addition and conclusions were drawn for expressing the biodegradability of pharmaceutical effluent on

  6. Effect of the Combination Hot Water - Calcium Chloride on the In Vitro Growth of Colletotrichum gloeosporioides and the Postharvest Quality of Infected Papaya

    Directory of Open Access Journals (Sweden)

    Lidia Elena Ayón-Reyna

    2017-12-01

    Full Text Available Anthracnose of papaya fruit caused by the fungus Colletotrichum gloeosporioides is one of the most economically important postharvest diseases. Hot water immersion (HW and calcium chloride (Ca treatments have been used to control papaya postharvest diseases; however, the effect of the combination HW-Ca on the pathogen growth and the development of the disease in infected papaya fruit has been scarcely studied. The aim of this study was to evaluate the effect of the HW-Ca treatment on the in vitro growth of C. gloesporioides conidia and the quality of infected papaya. In vitro, the HW-Ca treated conidia showed reduced mycelial growth and germination. In vivo, the HW-Ca treatment of infected papaya delayed for 5 days the onset of the anthracnose symptoms and improved the papaya postharvest quality. The combined treatment HW-Ca was better than any of the individual treatments to inhibit the in vitro development of C. gloeosporioides and to reduce the negative effects of papaya anthracnose.

  7. Identification and characterization of a new Bacillus atrophaeus strain B5 as biocontrol agent of postharvest anthracnose disease in soursop (Annona muricata) and avocado (Persea americana).

    Science.gov (United States)

    Guardado-Valdivia, Lizeth; Tovar-Pérez, Erik; Chacón-López, Alejandra; López-García, Ulises; Gutiérrez-Martínez, Porfirio; Stoll, Alexandra; Aguilera, Selene

    2018-05-01

    Anthracnose is a fungal disease caused by Colletotrichum species that is detrimental to numerous fruit, including soursop and avocado. The use of fungicides to maintain the high quality of fruit creates a potential health risk. One alternative to this problem is the biological control, which has been applied successfully during postharvest. The Bacillus species are one of the most studied biological agents against postharvest pathogens because accomplish their biocontrol performance by producing a variety of metabolites. In this study, we evaluated the activity of metabolites contained in the cell free supernatant, obtained from Bacillus strain B5 culture, against micelial growth and spore germination of two virulent strains of C. gloeosporioides isolated from soursop and avocado. On the basis of 16S rDNA gene sequence analysis, this strain was identified as Bacillus atrophaeus. A preventive treatment using cell free supernatant, reduced severity and incidence of anthracnose disease on harvested soursop and avocado fruit. B. atrophaeus strain B5 harbors genes involved in the production of antibiotics such as surfactin, bacillomycin and iturin, which could be contributing to the efficiency of the preventive treatment during postharvest. The antagonistic role of metabolites contained in the cell free supernatant against anthracnose disease, provide a new approach by which to attack this problem and can help reduce the use of chemical pesticides, environmental pollution, leading to the safer fruit preservation. Copyright © 2018 Elsevier GmbH. All rights reserved.

  8. System analysis for technology transfer readiness assessment of horticultural postharvest

    Science.gov (United States)

    Hayuningtyas, M.; Djatna, T.

    2018-04-01

    Availability of postharvest technology is becoming abundant, but only a few technologies are applicable and useful to a wider community purposes. Based on this problem it requires a significant readiness level of transfer technology approach. This system is reliable to access readiness a technology with level, from 1-9 and to minimize time of transfer technology in every level, time required technology from the selection process can be minimum. Problem was solved by using Relief method to determine ranking by weighting feasible criteria on postharvest technology in each level and PERT (Program Evaluation Review Technique) to schedule. The results from ranking process of post-harvest technology in the field of horticulture is able to pass level 7. That, technology can be developed to increase into pilot scale and minimize time required for technological readiness on PERT with optimistic time of 7,9 years. Readiness level 9 shows that technology has been tested on the actual conditions also tied with estimated production price compared to competitors. This system can be used to determine readiness of technology innovation that is derived from agricultural raw materials and passes certain stages.

  9. Postharvest conservation of alstroemeria ‘ajax’ using 1-methylcyclopropene

    Directory of Open Access Journals (Sweden)

    Vanessa Cury Galati

    Full Text Available ABSTRACT Cut flowers deteriorate quickly and require postharvest technologies to increase their durability, which is usually around 8 days. Due to the scarce information related to postharvest physiology of Alstroemeria cut flowers, this study aimed to verify the best dose of 1-methylcyclopropene (1-MCP to the postharvest conservation of inflorescences of Alstroemeria cv. Ajax, considering the factors associated with floral senescence and loss of the decorative life. The stems were submitted to four doses of 1-MCP (0; 100; 250; 500 ppb, then placed in containers with distilled water and stored at room temperature (22 ºC. The treatments were performed in triplicate containing three stems per replicate. The evaluations were performed every three days for a total of 12 days of storage. An F test was conducted, and the means were compared by the Tukey test (p≤0.05. Among the applied treatments the dose of 500 ppb of 1-MCP reduces the loss of water of the stems of alstroemerias during the storage period, keeping the petals turgids and the levels of carotenoids and anthocyanins high, however, this was not enough to keep the decorative quality of the flowers, once the 1-MCP did not solve the problems of yellowing of the leaves and floral openning, which are important characteristics for its commercialization.

  10. Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

    Directory of Open Access Journals (Sweden)

    Elizandra Pivotto Pavanello

    2015-12-01

    Full Text Available ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole associated with postharvest application of T. harzianum, after cold storage (with and without application, in three evaluation times (zero, two and four days at 20 °C, resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

  11. Hairy nightshade as a potential Potato leafroll virus (Luteoviridae: Polerovirus) inoculum source in Pacific Northwest potato ecosystems.

    Science.gov (United States)

    Srinivasan, R; Alvarez, J M

    2008-09-01

    Hairy nightshade, Solanum sarrachoides, is a solanaceous weed found abundantly in Pacific Northwest potato ecosystems. It serves as a reservoir for one of the important potato viruses, Potato leafroll virus (PLRV) (Luteoviridae: Polerovirus), and its most important vector, the green peach aphid, Myzus persicae (Homoptera: Aphididae). Laboratory research indicated an increased green peach aphid settling and performance on S. sarrachoides than on potato. It also revealed that green peach aphids transmitted PLRV more efficiently from S. sarrachoides to potato than from potato to potato. To test the efficiency of S. sarrachoides as an inoculum source in the field, a two season (2004 and 2005) trial was conducted at Kimberly, Idaho. Two inoculum sources, PLRV-infected potato and PLRV-infected S. sarrachoides, were compared in this trial. Green peach aphid density and temporal and spatial PLRV spread were monitored at weekly intervals. Higher densities of green peach aphids were observed on plots with S. sarrachoides and inoculum sources (PLRV-infected S. sarrachoides and potato) than on plots without S. sarrachoides and inoculum sources. PLRV infection in plots with PLRV-infected S. sarrachoides was similar to or slightly higher than in plots with PLRV-infected potato as an inoculum source. Temporal and spatial PLRV spread was similar in plots with either inoculum source. Thus, S. sarrachoides is as efficient as or a better PLRV inoculum source than potato.

  12. Potential of UVC germicidal irradiation in suppressing crown rot disease, retaining postharvest quality and antioxidant capacity of Musa AAA "Berangan" during fruit ripening.

    Science.gov (United States)

    S Mohamed, Nuratika Tamimi; Ding, Phebe; Kadir, Jugah; M Ghazali, Hasanah

    2017-09-01

    Crown rot caused by fungal pathogen is the most prevalent postharvest disease in banana fruit that results significant economic losses during transportation, storage, and ripening period. Antifungal effects of ultraviolet C (UVC) irradiation at doses varied from 0.01 to 0.30 kJ m -2 were investigated in controlling postharvest crown rot disease, maintenance of fruit quality, and the effects on antioxidant capacity of Berangan banana fruit during ripening days at 25 ± 2°C and 85% RH. Fruits irradiated with 0.30 kJ m -2 exhibited the highest (i.e., 62.51%) reduction in disease severity. However, the application of UVC at all doses caused significant browning damages on fruit peel except the dose of 0.01 kJ m -2 . This dose synergistically reduced 46.25% development of postharvest crown and did not give adverse effects on respiration rate, ethylene production, weight loss, firmness, color changes, soluble solids concentration, titratable acidity, and pH in banana as compared to the other treatments and control. Meanwhile, the dose also enhanced a significant higher level of total phenolic content, FRAP, and DPPH values than in control fruits indicating the beneficial impact of UVC in fruit nutritional quality. The results of scanning electron micrographs confirmed that UVC irradiation retarded the losses of wall compartments, thereby maintained the cell wall integrity in the crown tissue of banana fruit. The results suggest that using 0.01 kJ m -2 UVC irradiation dose as postharvest physical treatment, the crown rot disease has potential to be controlled effectively together with maintaining quality and antioxidant of banana fruit.

  13. Simultaneous heavy metals removal and municipal sewage sludge dewaterability improvement in bioleaching processes by various inoculums.

    Science.gov (United States)

    Shi, Chaohong; Zhu, Nengwu; Shang, Ru; Kang, Naixin; Wu, Pingxiao

    2015-11-01

    The heavy metals content and dewaterability of municipal sewage sludge (MSS) are important parameters affecting its subsequent disposal and land application. Six kinds of inoculums were prepared to examine the characteristics of heavy metals removal and MSS dewaterability improvement in bioleaching processes. The results showed that Cu, Zn and Cd bioleaching efficiencies (12 days) were 81-91, 87-93 and 81-89%, respectively, which were significantly higher than those of Fe-S control (P bioleaching boosted by the prepared inoculums could also significantly enhance MSS dewaterability (P bioleaching for heavy metals removal and dewaterability improvement. It also suggested that the synergy of sulfur/ferrous-oxidizing bacteria (SFOB) enriched from AMD and the cooperation of exogenous and indigenous SFOB significantly promoted bioleaching efficiencies.

  14. Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time

    DEFF Research Database (Denmark)

    Hartzen, S H; Andersen, L P; Bremmelgaard, A

    1997-01-01

    No standardized method of susceptibility testing for Helicobacter pylori is currently available, so before a large agar dilution study comprising 230 H. pylori strains belonging to more than 80 genetically different groups was initiated, we performed a relatively small preliminary study....../spot) as the inoculum and 72 h as the incubation time. A modest inoculum effect was noted for amoxicillin and metronidazole. By the methodology derived from our preliminary study, the susceptibilities of 230 H. pylori strains to six antibiotics were subsequently determined. The results were generally in accord...... with those of others, and apart from metronidazole, the MIC of which for approximately 25% of the strains tested was >8 microg/ml, resistance was low in Denmark. The situation might, however, quickly change when and if the number of indications for antibiotic therapy for H. pylori infections increase...

  15. Use of disposable reactors to generate inoculum cultures for E. coli production fermentations.

    Science.gov (United States)

    Mahajan, Ekta; Matthews, Timothy; Hamilton, Ryan; Laird, Michael W

    2010-01-01

    Disposable technology is being used more each year in the biotechnology industry. Disposable bioreactors allow one to avoid expenses associated with cleaning, assembly and operations, as well as equipment validation. The WAVE bioreactor is well established for Chinese Hamster Ovary (CHO) production, however, it has not yet been thoroughly tested for E. coli production because of the high oxygen demand and temperature maintenance requirements of that platform. The objective of this study is to establish a robust process to generate inoculum for E. coli production fermentations in a WAVE bioreactor. We opted not to evaluate the WAVE system for production cultures because of the high cell densities required in our current E. coli production processes. Instead, the WAVE bioreactor 20/50 system was evaluated at laboratory scale (10-L) to generate inoculum with target optical densities (OD(550)) of 15 within 7-9 h (pre-established target for stainless steel fermentors). The maximum settings for rock rate (40 rpm) and angle (10.5) were used to maximize mass transfer. The gas feed was also supplemented with additional oxygen to meet the high respiratory demand of the culture. The results showed that the growth profiles for the inoculum cultures were similar to those obtained from conventional stainless steel fermentors. These inoculum cultures were subsequently inoculated into 10-L working volume stainless steel fermentors to evaluate the inocula performance of two different production systems during recombinant protein production. The results of these production cultures using WAVE inocula showed that the growth and recombinant protein production was comparable to the control data set. Furthermore, an economic analysis showed that the WAVE system would require less capital investment for installation and operating expenses would be less than traditional stainless steel systems. (c) 2010 American Institute of Chemical Engineers

  16. Effect of Substrate-Inoculum Ratio on the Biochemical Methane Potential of Municipal Biowastes

    OpenAIRE

    Parra-Orobio Brayan Alexis; Torres-Lozada Patricia; Marmolejo-Rebellón Luis Fernando; Cárdenas-Cleves Lina Marcela; Vásquez-Franco Carlos; Torres-López Wilmar Alexander; Ordoñez-Andrade José Abdón

    2015-01-01

    Biowastes are the predominant fraction of municipal solid waste (MSW) of developing countries. Biowastes are characterized by a high content of organic matter; characteristics which facilitates its transformation through biological processes such as anaerobic digestion (AD). Using biochemical methane potential (PBM) assays, in this study we evaluated the influence of substrate-inoculum (S/I) ratio on the AD of biowaste from MSW. The S/I ranged between 0.25 to 9 gSVsubstrate * ...

  17. Reactor performances and microbial communities of biogas reactors: effects of inoculum sources.

    Science.gov (United States)

    Han, Sheng; Liu, Yafeng; Zhang, Shicheng; Luo, Gang

    2016-01-01

    Anaerobic digestion is a very complex process that is mediated by various microorganisms, and the understanding of the microbial community assembly and its corresponding function is critical in order to better control the anaerobic process. The present study investigated the effect of different inocula on the microbial community assembly in biogas reactors treating cellulose with various inocula, and three parallel biogas reactors with the same inoculum were also operated in order to reveal the reproducibility of both microbial communities and functions of the biogas reactors. The results showed that the biogas production, volatile fatty acid (VFA) concentrations, and pH were different for the biogas reactors with different inocula, and different steady-state microbial community patterns were also obtained in different biogas reactors as reflected by Bray-Curtis similarity matrices and taxonomic classification. It indicated that inoculum played an important role in shaping the microbial communities of biogas reactor in the present study, and the microbial community assembly in biogas reactor did not follow the niche-based ecology theory. Furthermore, it was found that the microbial communities and reactor performances of parallel biogas reactors with the same inoculum were different, which could be explained by the neutral-based ecology theory and stochastic factors should played important roles in the microbial community assembly in the biogas reactors. The Bray-Curtis similarity matrices analysis suggested that inoculum affected more on the microbial community assembly compared to stochastic factors, since the samples with different inocula had lower similarity (10-20 %) compared to the samples from the parallel biogas reactors (30 %).

  18. Cefazolin high-inoculum effect in methicillin-susceptible Staphylococcus aureus from South American hospitals.

    Science.gov (United States)

    Rincón, Sandra; Reyes, Jinnethe; Carvajal, Lina Paola; Rojas, Natalia; Cortés, Fabián; Panesso, Diana; Guzmán, Manuel; Zurita, Jeannete; Adachi, Javier A; Murray, Barbara E; Nannini, Esteban C; Arias, Cesar A

    2013-12-01

    Clinical failures with cefazolin have been described in high-inoculum infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) producing type A β-lactamase. We investigated the prevalence of the cefazolin inoculum effect (InE) in MSSA from South American hospitals, since cefazolin is used routinely against MSSA due to concerns about the in vivo efficacy of isoxazolyl penicillins. MSSA isolates were recovered from bloodstream (n = 296) and osteomyelitis (n = 68) infections in two different multicentre surveillance studies performed in 2001-02 and 2006-08 in South American hospitals. We determined standard-inoculum (10(5)cfu/mL) and high-inoculum (10(7) cfu/mL) cefazolin MICs. PFGE was performed on all isolates that exhibited a cefazolin InE. Multilocus sequence typing (MLST) and sequencing of part of blaZ were performed on representative isolates. The overall prevalence of the cefazolin InE was 36% (131 isolates). A high proportion (50%) of MSSA isolates recovered from osteomyelitis infections exhibited the InE, whereas it was observed in 33% of MSSA recovered from bloodstream infections. Interestingly, Ecuador had the highest prevalence of the InE (45%). Strikingly, 63% of MSSA isolates recovered from osteomyelitis infections in Colombia exhibited the InE. MLST revealed that MSSA isolates exhibiting the InE belonged to diverse genetic backgrounds, including ST5, ST8, ST30 and ST45, which correlated with the prevalent methicillin-resistant S. aureus clones circulating in South America. Types A (66%) and C (31%) were the most prevalent β-lactamases. Our results show a high prevalence of the cefazolin InE associated with type A β-lactamase in MSSA isolates from Colombia and Ecuador, suggesting that treatment of deep-seated infections with cefazolin in those countries may be compromised.

  19. Anaerobic biodegradability of Category 2 animal by-products: methane potential and inoculum source.

    Science.gov (United States)

    Pozdniakova, Tatiana A; Costa, José C; Santos, Ricardo J; Alves, M M; Boaventura, Rui A R

    2012-11-01

    Category 2 animal by-products that need to be sterilized with steam pressure according Regulation (EC) 1774/2002 are studied. In this work, 2 sets of experiments were performed in mesophilic conditions: (i) biomethane potential determination testing 0.5%, 2.0% and 5.0% total solids (TS), using sludge from the anaerobic digester of a wastewater treatment plant as inoculum; (ii) biodegradability tests at a constant TS concentration of 2.0% and different inoculum sources (digested sludge from a wastewater treatment plant; granular sludge from an upflow anaerobic sludge blanket reactor; leachate from a municipal solid waste landfill; and sludge from the slaughterhouse wastewater treatment anaerobic lagoon) to select the more adapted inoculum to the substrate in study. The higher specific methane production was of 317 mL CH(4)g(-1) VS(substrate) for 2.0% TS. The digested sludge from the wastewater treatment plant led to the lowest lag-phase period and higher methane potential rate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Anaerobic biodigestion of sugarcane vinasse under mesophilic conditions using manure as inoculum

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Farias Silva

    2016-11-01

    Full Text Available Sugarcane vinasse is one of the most polluting residues produced by Brazilian ethanol industries, mainly because of its harmful effects on the environmental, such as high organic matter load and acidity. Anaerobic digestion is a highly efficient wastewater treatment method that could potentially be used to treat sugarcane vinasse. This study examined the anaerobic biodigestion of sugarcane vinasse in mesophilic conditions (30 - 45°C by varying the inoculum concentration (0.5 to 5.5% and pH (6 - 8. Changes of Chemical Oxygen Demand (COD, total solids content, and yield and composition of biogas after the biodigestion of the vinasse were assessed. The vinasse was efficiently digested under mesophilic anaerobic conditions over a 23-day Hydraulic Retention Time (HRT and a 5-day acidogenic phase with a consequent reduction of COD (54 - 83% and total solids (52 - 87%. Statistical analyses at a confidence level of 95% suggested that temperature, pH and inoculum concentration did not influence on the anaerobic biodigestion of the vinasse. The optimal operating parameters were found to be temperatures of 30 - 35°C, inoculum concentration of 0.5% and pH of 6 - 7. The results emphasize the promising use of the treated sugarcane vinasse as a biofertilizer for agriculture, indicating that the anaerobic digestion process is an excellent alternative for Brazilian ethanol industries.

  1. Inoculum development by using activated sludge to remove hydrogen sulphide (H2S through biofiltration*

    Directory of Open Access Journals (Sweden)

    Alejandra Mora

    2005-07-01

    Full Text Available Different activated sludges were used for developing an inoculum able to degrade hydrogen sulphide in a pilot scale biofiltration plant using two different support materials: sugarcane bagasse and this bagasse mixed with pumice stone. Adapting and selecting microbial species which degrade hydrogen sulphide (H2S was aided by adding nutrients plus a specific substrate to the activated sludge. Population variation was monitored within the different trophic groups in the biofiter medium during pilot scale plant operation, a general trend towards sulphur-oxidising bacteria (SOB growth being observed as was a decrease in heterotrophic bacteria, molds and yeasts. The activated sludge which showed the highest substrate degradation speed was selected for standardising inoculum preparation; the different nutritional mediums were evaluated during this process. Measuring some variables for controlling the process led to choosing the pH for determining the proper point of inoculum adaptation for this specific substrate. The inoculation procedure and support characteristics in terms of establishing and developing the microbial species increased biofilter removal efficiency by up to 99% from start-up. Key words: biofilter, activated sludge, adapted microorganisms, sulphur-oxidising bacteria, respirometry. Este artículo es el resultado de un proyecto cofinanciado por Colciencias y desarrollado por un grupo de investigadores vinculados al proyecto a través de las entidades Corporación

  2. Enhancing anaerobic digestion of food waste through biochemical methane potential assays at different substrate: inoculum ratios.

    Science.gov (United States)

    Hobbs, Shakira R; Landis, Amy E; Rittmann, Bruce E; Young, Michelle N; Parameswaran, Prathap

    2018-01-01

    Food waste has a high energy potential that can be converted into useful energy in the form of methane via anaerobic digestion. Biochemical Methane Potential assays (BMPs) were conducted to quantify the impacts on methane production of different ratios of food waste. Anaerobic digester sludge (ADS) was used as the inoculum, and BMPs were performed at food waste:inoculum ratios of 0.42, 1.42, and 3.0g chemical oxygen demand/g volatile solids (VS). The 1.42 ratio had the highest CH 4 -COD recovery: 90% of the initial total chemical oxygen demand (TCOD) was from food waste, followed by ratios 0.42 and 3.0 at 69% and 57%, respectively. Addition of food waste above 0.42 caused a lag time for CH 4 production that increased with higher ratios, which highlighted the negative impacts of overloading with food waste. The Gompertz equation was able to represent the results well, and it gave lag times of 0, 3.6 and 30days and maximum methane productions of 370, 910, and 1950mL for ratios 0.42, 1.42 and 3.0, respectively. While ratio 3.0 endured a long lag phase and low VSS destruction, ratio 1.42 achieved satisfactory results for all performance criteria. These results provide practical guidance on food-waste-to-inoculum ratios that can lead to optimizing methanogenic yield. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells.

    KAUST Repository

    Siegert, Michael; Li, Xiu-Fen; Yates, Matthew D; Logan, Bruce E

    2014-01-01

    High current densities in microbial electrolysis cells (MECs) result from the predominance of various Geobacter species on the anode, but it is not known if archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD) sludge dominated by acetoclastic Methanosaeta, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% (w/v) resulted in the highest methane production rates (0.27 mL mL(-1) cm(-2), gas volume normalized by liquid volume and cathode projected area) and highest peak current densities (0.5 mA cm(-2)) for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and quantitative PCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance.

  4. Fermentation of Rice Straw Uses Mix Inoculum of Anaerobe Facultative Bacteria Isolate from Buffalo Rumen

    International Nuclear Information System (INIS)

    Sasongko, W. T.; Irawan Sugoro

    2004-01-01

    Rice straw quality could be increased as feed by fermentation which has been mixed with bacteria inoculum from buffalo rumen. This experiment used rice straw from Atomita 4, four treatments and one control, i.e. A (rice straw, molasses 5 %, urea 5 %, and inoculum 10 %), B (rice straw, molasses 5 %, and urea 5 %), C (rice straw, molasses 5 %, and inoculum 10 %), D (rice straw and molasses 5 %), and K (control) have been used in this experiment. The parameters were digestibility of dry matter and organic matter, VFA, ammonia and in vitro gas production. The result, showed that the highest gas production, dry matter and organic matter digestibility occurred on A i.e. 17.48 ml/200 mg, 57.78%, and 52.39 %. The highest ammonia occurred on D (32.99 mg/100 ml) and the highest VFA occurred on C (12.36 mmol/100 ml). The concentration of ammonia and VFA of A significant to treatment of D and C). It may be concluded that the A treatment is the best and have potency to be develop. (author)

  5. Extension of Small-Scale Postharvest Horticulture Technologies—A Model Training and Services Center

    Directory of Open Access Journals (Sweden)

    Lisa Kitinoja

    2015-07-01

    Full Text Available A pilot Postharvest Training and Services Center (PTSC was launched in October 2012 in Arusha, Tanzania as part of a United States Agency for International Development (USAID funded project. The five key components of the PTSC are (1 training of postharvest trainers, (2 postharvest training and demonstrations for local small-scale clientele, (3 adaptive research, (4 postharvest services, and (5 retail sales of postharvest tools and supplies. During the years of 2011–2012, a one year e-learning program was provided to 36 young horticultural professionals from seven Sub-Saharan African countries. These postharvest specialists went on to train more than 13,000 local farmers, extension workers, food processors, and marketers in their home countries in the year following completion of their course. Evaluators found that these specialists had trained an additional 9300 people by November 2014. When asked about adoption by their local trainees, 79% reported examples of their trainees using improved postharvest practices. From 2012–2013, the project supported 30 multi-day training programs, and the evaluation found that many of the improved practices being promoted were adopted by the trainees and led to increased earnings. Three PTSC components still require attention. Research activities initiated during the project are incomplete, and successful sales of postharvest goods and services will require commitment and improved partnering.

  6. Metabolomics analysis of postharvest ripening heterogeneity of ‘Hass' avocadoes

    NARCIS (Netherlands)

    Pedreschi, R.; Munoz, P.; Robledo, P.; Becerra, C.; Defilippi, B.G.; Eekelen, van H.D.L.M.; Mumm, R.; Westra, E.H.; Vos, de R.C.H.

    2014-01-01

    The complex physiology of ‘Hass’ avocado renders its postharvest ripening heterogeneous and unpre-dictable. Several approaches have previously been undertaken to broaden our understanding of the causesof this postharvest ripening heterogeneity but without much success. In this study, a fruit biopsy

  7. Breeding as a tool for improving postharvest quality characters of lily and tulip flowers

    NARCIS (Netherlands)

    Meulen-Muisers, van der J.J.M.; Oeveren, van J.C.; Tuyl, van J.M.

    1997-01-01

    Segregation of postharvest quality characters was studied in lily and tulip. A large variation in longevity of both lily and tulip flowers was found within populations tested at individual plant level. Other postharvest quality characters like number of flowers per stem, male sterility (lily) and

  8. Effects of cuticular wax on the postharvest quality of blueberry fruit.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Chen, Hangjun; Fang, Xiangjun; Zheng, Yonghua

    2018-01-15

    The blueberry fruit has a light-blue appearance because its blue-black skin is covered with a waxy bloom. This layer is easily damaged or removed during fruit harvesting and postharvest handling. We investigated the effects of wax removal on the postharvest quality of blueberry fruit and their possible mechanisms. The removal of natural wax on the fruit was found to accelerate the postharvest water loss and decay, reduce the sensory and nutritional qualities, and shorten the shelf-life. Wax removal decreased the activities of antioxidant enzymes and contents of antioxidants, and accelerated accumulation of ROS and lipid peroxidation, especially at the later period of storage. Moreover, the organellar membrane structure was disrupted in fruit with wax removed. These results indicate that cuticular wax plays an important role in maintaining the postharvest quality and delaying fruit senescence. The results should improve our understanding for better preservation of postharvest quality of blueberry fruit. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Effects of Chitin and Its Derivative Chitosan on Postharvest Decay of Fruits: A Review

    Directory of Open Access Journals (Sweden)

    Weimin Liu

    2011-01-01

    Full Text Available Considerable economic losses to harvested fruits are caused by postharvest fungal decay during transportation and storage, which can be significantly controlled by synthetic fungicides. However, considering public concern over pesticide residues in food and the environment, there is a need for safer alternatives for the control of postharvest decay to substitute synthetic fungicides. As the second most abundant biopolymer renewable source in nature, chitin and its derivative chitosan are widely used in controlling postharvest decay of fruits. This review aims to introduce the effect of chitin and chitosan on postharvest decay in fruits and the possible modes of action involved. We found most of the actions discussed in these researches rest on physiological mechanisms. All of the mechanisms are summarized to lay the groundwork for further studies which should focus on the molecular mechanisms of chitin and chitosan in controlling postharvest decay of fruits.

  10. [In vitro simulation of rabbit cecal fermentation in a semi- continuous flow fermentor. II. Effect of inoculum type].

    Science.gov (United States)

    Adjiri, D; Bouillier-Oudot, M; Lebas, F; Candau, M

    1992-01-01

    Two Rusitec fermentors were operated under identical conditions. One was seeded with an inoculum of rabbit caecal contents, and the other with bovine rumen contents. The fermentation substrate was rabbit feed that had been digested with amylase and pepsin. The substrate constituents (organic matter, OM and NDF) were lost in 48 h at a significantly higher rate in the presence of rumen inoculum (OM: +10%, NDF: +15%). The pHs of the 2 fermentors were similar at pH 6.6. The fermentors produced similar amounts of protein nitrogen per 24 h, after 6 d of adaptation. Volatile fatty acid production was slightly higher in the presence of rumen inoculum. The fermentor inoculated with rumen contents produced a higher percentage of propionic acid (25%) than of butyric acid (7%), while fermentation with rabbit caecal contents gave the opposite ratio (C3/C4 = 0.81). Consequently, only the rabbit caecal inoculum provided the fermentation profile characteristic of the species.

  11. Isolation and characterization of Enterobacteriaceae species infesting post-harvest strawberries and their biological control using bacteriophages.

    Science.gov (United States)

    Kurtböke, D Ipek; Palk, A; Marker, A; Neuman, C; Moss, L; Streeter, K; Katouli, M

    2016-10-01

    Strawberry is a significantly consumed fruit worldwide, mostly without being subjected to disinfection processes. During the harvest and transfer from farm to consumers as well as where organic farming practises have been employed, the surface of the fruit may become contaminated by pathogenic bacteria. Post-harvest strawberry fruits in punnets available for public consumption were thus screened for the presence of enteric bacteria in the Sunshine Coast region of Queensland, Australia. Some of the tested samples (13 %) were found to carry such bacteria and even in greater numbers if organic amendments were used (69 %). The bacteria were found to belong in the genera of Escherichia, Enterobacter, Raoultella, Klebsiella, Pantoea, Shigella, Citrobacter and Cronobacter within the family Enterobacteriaceae. Some of the isolates were found to adhere to Caco-2 cells representing human gut epithelium as well as carrying virulence and toxin genes. Resistance mostly against sulphafurazole, cefoxitin, ampicillin and nitrofurantoin was found among 14 different antimicrobial agents tested including 100 % resistance to cefoxitin and ampicillin in the genus Pantoea. In the second phase of the study, bacteriophages were isolated against the isolates and were subsequently applied to post-harvest fruits. A significant (P ≤ 0.001) reduction in the number of enteric bacteria was observed when a high-titre polyvalent bacteriophage suspension (×10(12) PFU/mL) was applied to the fruit surface. Bacteriophages also decreased the adhesion of the Escherichia coli isolates to Caco-2 cells. Findings might indicate that biological control using bacteriophages might be of significant value for the industry targeting to reduce pathogenic loads of bacteria on the fruit.

  12. Efficacy of plant essential oils on postharvest control of rots caused by fungi on different stone fruits in vivo.

    Science.gov (United States)

    Lopez-Reyes, Jorge Giovanny; Spadaro, Davide; Prelle, Ambra; Garibaldi, Angelo; Gullino, Maria Lodovica

    2013-04-01

    The antifungal activity of plant essential oils was evaluated as postharvest treatment on stone fruit against brown rot and grey mold rot of stone fruit caused by Monilinia laxa and Botrytis cinerea, respectively. The essential oils from basil (Ocimum basilicum), fennel (Foeniculum sativum), lavender (Lavandula officinalis), marjoram (Origanum majorana), oregano (Origanum vulgare), peppermint (Mentha piperita), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), savory (Satureja montana), thyme (Thymus vulgaris), and wild mint (Mentha arvensis) were tested at two different concentrations on apricots (cv. Kyoto and cv. Tonda di Costigliole), nectarines (cv. Big Top and cv. Nectaross) and plums (cv. Italia and cv. TC Sun). The volatile composition of the essential oils tested was determined by gas chromatography-mass spectrometry analysis. The treatments containing essential oils from oregano, savory, and thyme at 1% (vol/vol) controlled both B. cinerea and M. laxa growing on apricots cv. Tonda di Costigliole and plums cv. Italia and cv. TC Sun; however, the same treatments were phytotoxic for the carposphere of nectarines cv. Big Top and cv. Nectaross. Treatments with 10% (vol/vol) essential oils were highly phytotoxic, notwithstanding their efficacy against the pathogens tested. The essential oils containing as major components α-pinene, p-cymene, carvacrol, and thymol showed similar results on stone fruit, so their antimicrobial activity and the phytotoxicity produced could be based on the concentration of their principal compounds and their synergistic activity. The efficacy of the essential oil treatments on control of fungal pathogens in postharvest depended on the fruit cultivar, the composition and concentration of the essential oil applied, and the length of storage.

  13. Advances in postharvest technologies to extend the storage life of minimally processed fruits and vegetables.

    Science.gov (United States)

    Ali, Asgar; Yeoh, Wei Keat; Forney, Charles; Siddiqui, Mohammed Wasim

    2017-10-26

    Minimally processed fresh produce is one of the fastest growing segments of the food industry due to consumer demand for fresh, healthy, and convenient foods. However, mechanical operations of cutting and peeling induce the liberation of cellular contents at the site of wounding that can promote the growth of pathogenic and spoilage microorganisms. In addition, rates of tissue senescence can be enhanced resulting in reduced storage life of fresh-cut fruits and vegetables. Chlorine has been widely adopted in the disinfection and washing procedures of fresh-cut produce due to its low cost and efficacy against a broad spectrum of microorganisms. Continuous replenishment of chlorine in high organic wash water can promote the formation of carcinogenic compounds such as trihalomethanes, which threaten human and environmental health. Alternative green and innovative chemical and physical postharvest treatments such as ozone, electrolyzed water, hydrogen peroxide, ultraviolet radiation, high pressure processing, and ultrasound can achieve similar reduction of microorganisms as chlorine without the production of harmful compounds or compromising the quality of fresh-cut produce.

  14. Effect of postharvest practices including degreening on citrus carpoplane microbial biomes.

    Science.gov (United States)

    Gomba, A; Chidamba, L; Korsten, L

    2017-04-01

    To investigate the effect of commercial citrus packhouse processing steps on the fruit surface microbiome of Clementines and Palmer navel oranges. Viable bacteria, yeast and fungi counts, and the pyrosequencing analysis of the 16S rRNA and ITS were used to evaluate the community structure and population dynamics of phylloepiphytic bacteria and fungi associated with commercial postharvest processing. Drenching significantly reduced microbial counts in all cases except for yeasts on navels, while the extent of degreening effects varied between the citrus varieties. Pyrosequencing analysis showed a total of 4409 bacteria and 5792 fungi nonchimeric unique sequences with an average of 1102 bacteria and 1448 fungi reads per sample. Dominant phyla on the citrus carpoplane were Proteobacteria (53·5%), Actinobacteria (19·9%), Bacteroidetes (5·6%) and Deinococcus-Thermus (5·4%) for bacteria and Ascomycota (80·5%) and Basidiomycota (9·8%) for fungi. Beginning with freshly harvested fruit fungal diversity declined significantly after drenching, but had little effect on bacteria and populations recovered during degreening treatments, including those for Penicillium sp. Packhouse processing greatly influences microbial communities on the citrus carpoplane. A broad orange biome was described with pyrosequencing and gave insight into the likely survival and persistence of pathogens, especially as they may affect the quality and safety of the packed product. A close examination of the microbiota of fruit and the impact of intervention strategies on the ecological balance may provide a more durable approach to reduce losses and spoilage. © 2017 The Society for Applied Microbiology.

  15. Mummified fruit as a source of inoculum and disease dynamics of olive anthracnose caused by Colletotrichum spp.

    Science.gov (United States)

    Moral, Juan; Trapero, Antonio

    2012-10-01

    Anthracnose, caused by Colletotrichum spp., is a destructive disease of olive fruit worldwide. The objective of this study was to investigate the influence of agronomical and weather factors on inoculum production using detached olive fruit and on the development of epidemics in the field. The pathogen produced very large numbers of conidia on rotted (>1.87 × 10(8) conidia/fruit) or mummified (>2.16 × 10(4) conidia/fruit) fruit under optimal conditions. On mummified fruit, conidial production was highest on mummies incubated at 20 to 25°C and 96 h of wetness. Repeated washings of mummies reduced conidial production until it was very low after five washings. When mummies were placed in the tree canopy, conidial production was not reduced after 6 months (May to October); but, when they were held on the soil or buried in the soil, conidial production comparatively decreased up to 10,000 times. Anthracnose epidemics on susceptible 'Hojiblanca' and 'Picudo' during three seasons (2005-08) were influenced by rainfall, temperature, and fruit ripening, and had three main phases: the latent period (May to October); the onset of the epidemic, which coincided with the beginning of fruit ripening (early November); and disease development, which was predicted by the Weibull model (November to March). No epidemics developed on the susceptible cultivars during the driest season (2007-08) or on the resistant 'Picual' olive during any of the three seasons. These results provide the basis for a forecasting system of olive anthracnose which could greatly improve the management of this disease.

  16. A rapid culture system uninfluenced by an inoculum effect increases reliability and convenience for drug susceptibility testing of Mycobacterium tuberculosis.

    Science.gov (United States)

    Jung, Yong-Gyun; Kim, Hyejin; Lee, Sangyeop; Kim, Suyeoun; Jo, EunJi; Kim, Eun-Geun; Choi, Jungil; Kim, Hyun Jung; Yoo, Jungheon; Lee, Hye-Jeong; Kim, Haeun; Jung, Hyunju; Ryoo, Sungweon; Kwon, Sunghoon

    2018-06-05

    The Disc Agarose Channel (DAC) system utilizes microfluidics and imaging technologies and is fully automated and capable of tracking single cell growth to produce Mycobacterium tuberculosis (MTB) drug susceptibility testing (DST) results within 3~7 days. In particular, this system can be easily used to perform DSTs without the fastidious preparation of the inoculum of MTB cells. Inoculum effect is one of the major problems that causes DST errors. The DAC system was not influenced by the inoculum effect and produced reliable DST results. In this system, the minimum inhibitory concentration (MIC) values of the first-line drugs were consistent regardless of inoculum sizes ranging from ~10 3 to ~10 8 CFU/mL. The consistent MIC results enabled us to determine the critical concentrations for 12 anti-tuberculosis drugs. Based on the determined critical concentrations, further DSTs were performed with 254 MTB clinical isolates without measuring an inoculum size. There were high agreement rates (96.3%) between the DAC system and the absolute concentration method using Löwenstein-Jensen medium. According to these results, the DAC system is the first DST system that is not affected by the inoculum effect. It can thus increase reliability and convenience for DST of MTB. We expect that this system will be a potential substitute for conventional DST systems.

  17. Control of postharvest decay in fruits and vegetables by irradiation

    International Nuclear Information System (INIS)

    Ismail, F.A.; Afifi, S.A.

    1976-01-01

    The effect of postharvest gamma-irradiation of strawberries and carrots on their organoleptic quality, storage capacity and chemical composition was investigated. Radiation doses of 25 krad for strawberries and 75 krad for carrots were chosen as optimum doses not causing significant changes in the organoleptic quality. It was found that strawberries and carrots irradiated with a dose of 25 and 75 krad, respectively, retained its microbiological stability even during storage at 12 0 C (strawberries) and at 25 - 30 0 C (carrots), respectively. It was also found that changes in the chemical composition depend on storage temperature and time and are not affected substantially by irradiation. (author)

  18. Inhibitory effects of crude extracts from several plants on postharvest pathogens of citrus

    Science.gov (United States)

    Gong, Mingfu; Guan, Qinlan; Xu, Shanshan

    2018-04-01

    China is one of the most important origin of citrus. Enormous economic losses was caused by fungal diseases in citrus harvest storage every year. The effective antimicrobial substances of garlic, ginger, celery and pepper were extracted by ethanol extraction and water extraction respectively. The inhibitory effects of the crude extract on Penicillium sp. caused fungal diseases in citrus harvest storage were also determined. The results showed that the extracts of garlic, ginger and celery had inhibitory effect on P. sp., but the extracts of pepper had no inhibitory effect on P. sp.. The garlic ethanol extracts had the best inhibitory effect on P. citrinum.

  19. Biocontrol ability and action mechanism of food-isolated yeast strains against Botrytis cinerea causing post-harvest bunch rot of table grape.

    Science.gov (United States)

    Parafati, Lucia; Vitale, Alessandro; Restuccia, Cristina; Cirvilleri, Gabriella

    2015-05-01

    Strains belonging to the species Saccharomyces cerevisiae, Wickerhamomyces anomalus, Metschnikowia pulcherrima and Aureobasidium pullulans, isolated from different food sources, were tested in vitro as biocontrol agents (BCAs) against the post-harvest pathogenic mold Botrytis cinerea. All yeast strains demonstrated antifungal activity at different levels depending on species and medium. Killer strains of W. anomalus and S. cerevisiae showed the highest biocontrol in vitro activity, as demonstrated by largest inhibition halos. The competition for iron and the ability to form biofilm and to colonize fruit wounds were hypothesized as the main action mechanisms for M. pulcherrima. The production of hydrolytic enzymes and the ability to colonize the wounds were the most important mechanisms for biocontrol activity in A. pullulans and W. anomalus, which also showed high ability to form biofilm. The production of volatile organic compounds (VOCs) with in vitro and in vivo inhibitory effect on pathogen growth was observed for the species W. anomalus, S. cerevisiae and M. pulcherrima. Our study clearly indicates that multiple modes of action may explain as M. pulcherrima provide excellent control of postharvest botrytis bunch rot of grape. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Banana fertigation with treated sanitary wastewater: postharvest and microbiological quality

    Directory of Open Access Journals (Sweden)

    Pablo Fernando Santos Alves

    2017-06-01

    Full Text Available Sewage may serve as a source of water and nutrients for plants. In this study, the effects of fertigation with treated sanitary wastewater from Janaúba Sewage Treatment Plant were evaluated on the postharvest and microbiological quality of ‘Prata-Anã’ banana. A randomized block experimental design was used. Four concentrations of wastewater were tested (70, 130, 170, and 200% of 150 kg ha-1 sodium. A wastewater-free control treatment was used for comparison. Two crop cycles were assessed for postharvest and microbiological quality. The parameters measured included total soluble solids, titratable acidity, total soluble solids/titratable acidity ratio, pH, total coliforms, and fecal coliforms on both the peel and the pulp. In the first crop cycle, both soluble solids and fruit pulp pH decreased as wastewater level increased up to a maximum of 141.5%. These correlations were not observed in the second cycle. Wastewater management did not affect the titratable acidity of the soluble solids. The agricultural application of treated sanitary wastewater provided banana fruits with a microbiological profile similar to that obtained with the control (pure water and with mineral fertilizers. A microbial balance is necessary to maintain the nutritional status of the banana crop.

  1. Bitter pit in apples: pre- and postharvest factors: A review

    International Nuclear Information System (INIS)

    Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

    2016-01-01

    Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

  2. Bitter pit in apples: pre- and postharvest factors: A review

    Energy Technology Data Exchange (ETDEWEB)

    Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

    2016-07-01

    Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

  3. Volatile aldehydes are promising broad-spectrum postharvest insecticides.

    Science.gov (United States)

    Hammond, D G; Rangel, S; Kubo, I

    2000-09-01

    A variety of naturally occurring aldehydes common in plants have been evaluated for their insecticidal activity and for phytotoxicity to postharvest fruits, vegetables, and grains. Twenty-nine compounds were initially screened for their activity against aphids on fava bean leaf disks. Application under reduced pressure (partial vacuum) for the first quarter of fumigation increased insecticidal activity severalfold. The 11 best aldehydes were assayed against aphids placed under the third leaf of whole heads of iceberg lettuce using the same two-tier reduced-pressure regime, which caused no additional detriment to the commodity over fumigation at atmospheric pressure. Phytotoxicity to naked and wrapped iceburg lettuce, green and red table grapes, lemon, grapefruit, orange, broccoli, avocado, cabbage, pinto bean, and rice at doses that killed 100% of aphids was recorded for three promising fumigants: propanal, (E)-2-pentenal, and 2-methyl-(E)-2-butenal. These three compounds have excellent potential as affordable postharvest insect control agents, killing 100% of the aphids with little or no detectable harm to a majority of the commodities tested. Preliminary assays indicate that similar doses are also effective against mealybugs, thrips, and whitefly.

  4. Susceptibility screening of hyphae-forming fungi with a new, easy, and fast inoculum preparation method.

    Science.gov (United States)

    Schmalreck, Arno; Willinger, Birgit; Czaika, Viktor; Fegeler, Wolfgang; Becker, Karsten; Blum, Gerhard; Lass-Flörl, Cornelia

    2012-12-01

    In vitro susceptibility testing of clinically important fungi becomes more and more essential due to the rising number of fungal infections in patients with impaired immune system. Existing standardized microbroth dilution methods for in vitro testing of molds (CLSI, EUCAST) are not intended for routine testing. These methods are very time-consuming and dependent on sporulating of hyphomycetes. In this multicentre study, a new (independent of sporulation) inoculum preparation method (containing a mixture of vegetative cells, hyphae, and conidia) was evaluated. Minimal inhibitory concentrations (MIC) of amphotericin B, posaconazole, and voriconazole of 180 molds were determined with two different culture media (YST and RPMI 1640) according to the DIN (Deutsches Institut für Normung) microdilution assay. 24 and 48 h MIC of quality control strains, tested per each test run, prepared with the new inoculum method were in the range of DIN. YST and RPMI 1640 media showed similar MIC distributions for all molds tested. MIC readings at 48 versus 24 h yield 1 log(2) higher MIC values and more than 90 % of the MICs read at 24 and 48 h were within ± 2 log(2) dilution. MIC end point reading (log(2 MIC-RPMI 1640)-log(2 MIC-YST)) of both media demonstrated a tendency to slightly lower MICs with RPMI 1640 medium. This study reports the results of a new, time-saving, and easy-to-perform method for inoculum preparation for routine susceptibility testing that can be applied for all types of spore-/non-spore and hyphae-forming fungi.

  5. Rotylenchulus reniformis on Greenhouse-grown Foliage Plants: Host Range and Sources of Inoculum.

    Science.gov (United States)

    Starr, J L

    1991-10-01

    Two sources of inoculum of reniform nematodes, Rotylenchulus reniformis, were identified for infestation of ornamental foliage plants in commercial greenhouses. These were water from a local canal system and rooted cuttings purchased from other sources. Eight ornamental plant species were identified as good hosts for the reniform nematode, with each species supporting a reniform population density equal to or greater than that supported by 'Rutgers' tomato and a reproduction factor of greater than 1.0. Nine other plant species were identified as poor hosts.

  6. Comparison of two possible routes of pathogen contamination of spinach leaves in a hydroponic cultivation system.

    Science.gov (United States)

    Koseki, Shigenobu; Mizuno, Yasuko; Yamamoto, Kazutaka

    2011-09-01

    The route of pathogen contamination (from roots versus from leaves) of spinach leaves was investigated with a hydroponic cultivation system. Three major bacterial pathogens, Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes, were inoculated into the hydroponic solution, in which the spinach was grown to give concentrations of 10⁶ and 10³ CFU/ml. In parallel, the pathogens were inoculated onto the growing leaf surface by pipetting, to give concentrations of 10⁶ and 10³ CFU per leaf. Although contamination was observed at a high rate through the root system by the higher inoculum (10⁶ CFU) for all the pathogens tested, the contamination was rare when the lower inoculum (10³ CFU) was applied. In contrast, contamination through the leaf occurred at a very low rate, even when the inoculum level was high. For all the pathogens tested in the present study, the probability of contamination was promoted through the roots and with higher inoculum levels. The probability of contamination was analyzed with logistic regression. The logistic regression model showed that the odds ratio of contamination from the roots versus from the leaves was 6.93, which suggested that the risk of contamination from the roots was 6.93 times higher than the risk of contamination from the leaves. In addition, the risk of contamination by L. monocytogenes was about 0.3 times that of Salmonella enterica subsp. enterica serovars Typhimurium and Enteritidis and E. coli O157:H7. The results of the present study indicate that the principal route of pathogen contamination of growing spinach leaves in a hydroponic system is from the plant's roots, rather than from leaf contamination itself.

  7. Effect of inoculum density and soil tillage on the development and severity of rhizoctonia root rot.

    Science.gov (United States)

    Schroeder, K L; Paulitz, T C

    2008-03-01

    Rhizoctonia spp. cause substantial yield losses in direct-seeded cereal crops compared with conventional tillage. To investigate the mechanisms behind this increased disease, soils from tilled or direct-seeded fields were inoculated with Rhizoctonia spp. at population densities from 0.8 to 250 propagules per gram and planted with barley (Hordeum vulgare). The incidence and severity of disease did not differ between soils with different tillage histories. Both R. solani AG-8 and R. oryzae stunted plants at high inoculum densities, with the latter causing pre-emergence damping-off. High inoculum densities of both species stimulated early production of crown roots in barley seedlings. Intact soil cores from these same tilled and direct-seeded fields were used to evaluate the growth of Rhizoctonia spp. from colonized oat seeds. Growth of R. oryzae was not affected by previous tillage history. However, R. solani AG-8 grew more rapidly through soil from a long-term direct-seeded field compared to tilled soils. The differential response between these two experiments (mixed, homogenized soil versus intact soil) suggests that soil structure plays a major role in the proliferation of R. solani AG-8 through soils with different tillage histories.

  8. Effect of inoculum sources on the enrichment of nitrite-dependent anaerobic methane-oxidizing bacteria.

    Science.gov (United States)

    He, Zhanfei; Cai, Chen; Shen, Lidong; Lou, Liping; Zheng, Ping; Xu, Xinhua; Hu, Baolan

    2015-01-01

    Nitrite-dependent anaerobic methane oxidation (n-damo) is a newly discovered biological process that couples anaerobic oxidation of methane (AOM) to nitrite reduction. In this study, three different inocula, methanogenic sludge, paddy soil, and freshwater sediment were used to enrich n-damo bacteria in three sequencing batch reactors (SBRs), and three n-damo enrichment cultures, C1, C2 and C3, were obtained, respectively. After 500 days of incubation, Methylomirabilis oxyfera-like bacteria and n-damo activities were observed in cultures C1, C2, and C3, and the specific activities were 0.8 ± 0.1, 1.4 ± 0.1, and 1.0 ± 0.1 μmol CH4 h(-1) g(-1) VSS, respectively. The copy numbers of 16S rRNA genes from cultures C1, C2, and C3 were 5.0 ± 0.4 × 10(8), 6.1 ± 0.1 × 10(9), and 1.0 ± 0.2 × 10(9) copies g(-1) dry weight, respectively. The results indicated that paddy soil is an excellent inoculum for n-damo bacterial enrichment. This work expanded the alternative source of n-damo inoculum and benefited the further research of n-damo process.

  9. Production of native arbuscular mycorrhizal fungi inoculum under different environmental conditions

    Directory of Open Access Journals (Sweden)

    Yamir Torres-Arias

    Full Text Available Abstract In order to obtain an arbuscular mycorrhizal fungi (AMF native inoculum from Sierra de Moa and determine the most appropriate conditions for its big scale production, four light and temperature combinations were tested in three plant species (Calophyllum antillanum, Talipariti elatum and Paspalum notatum. Growth and development parameters, as well as the mycorrhizal functioning of the seedlings were evaluated. The natural light treatment under high temperatures (L-H was the most suitable for the growth and development of the three plant species, showing the highest total biomass values, mainly of root, and a positive root-shoot ratio balance. This treatment also promoted higher values of root mycorrhizal colonization, external mycelium and AMF spore density. A total of 38 AMF species were identified among the plants and environmental conditions tested. Archaeospora sp.1, Glomus sp.5, Glomus brohultii and G. glomerulatum were observed in all the treatments. The L-H condition can be recommended for native inoculum production, as it promotes a better expression of the AM symbiosis and an elevated production of mycorrhizal propagules.

  10. Effect of gamma irradiation and its convergent treatment for control of postharvest Botrytis cinerea of cut roses

    International Nuclear Information System (INIS)

    Chu, Eun-Hee; Shin, Eun-Jung; Park, Hae-Jun; Jeong, Rae-Dong

    2015-01-01

    Postharvest diseases cause considerable losses to harvested crops. Among them, gray mold (Botrytis cinerea) is a major problem of exporting to cut rose flowers into Korea. Irradiation treatment is an alternative to phytosanitary purposes and a useful nonchemical approach to the control of postharvest diseases. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against B. cinerea on cut rose varieties, ‘Shooting Star’ and ‘Babe’. The irradiating dose required to reduce the population by 90%, D 10 , was 0.99 kGy. Gamma irradiation showed complete inhibition of spore germination and mycelial growth of B. cinerea, especially 4.0 kGy in vitro. Antifungal activity of gamma irradiation on rose B. cinerea is a dose-dependent manner. A significant phytotoxicity such as bent neck in cut rose quality was shown from gamma irradiation at over 0.4 kGy (p<0.05) in both varieties. Although there is no significant difference in both varieties for fresh weight, in the case of flower rate, ‘Babe’ shows more sensitivity than ‘Shooting Star’. In vivo assays demonstrated that established doses in in vitro, over 4 kGy, could completely inactive fungal pathogens, but such high doses can cause severe flowers damage. Thus, to eliminate negative impact on their quality, gamma irradiation was evaluated at lower doses in combination with an eco-friendly chemical, sodium dichloroisocyanurate (NaDCC) to examine the inhibition of B. cinerea. Intriguingly, only the combined treatment with 0.2 kGy of gamma irradiation and 70 ppm of NaDCC exhibited significant synergistic antifungal activity against blue mold decay in both varieties. Together, these results suggest that a synergistic effect of the combined treatment with gamma irradiation and NaDCC can be efficiently used to control the postharvest diseases in cut rose flowers, and will provide a promising technology for horticulture products for exportation. - Highlights: • Gamma irradiation and Na

  11. Associations between milking practices, somatic cell counts and milk postharvest losses in smallholder dairy and pastoral camel herds in Kenya

    Directory of Open Access Journals (Sweden)

    Olivier B. Kashongwe

    2017-06-01

    Full Text Available On-farm hygienic practices are important in assuring quality and safety of milk for consumers and for reducing losses at production and at post-harvest. This study investigated the relationship between milking practices, mastitis as well as milk somatic cell counts (SCC and the effects of high SCC on milk production and post-harvest losses (PHL in smallholder dairy (n = 64 and pastoral camel (n = 15 herds in Kenya. The collected data included milking practices, mastitis test on udder quarters (n = 1236 and collection of milk samples for laboratory analyses: SCC, detection of Staphylococcus aureus and Streptococcus species. Production losses were computed as a proportion of cows and herds with SCC (>200,000 cells/mL and PHL as quantity of milk exceeding 4 × 105 cells/mL. Practices associated with production herds included hands, udder washing and drying, and milk let down stimulation with calves suckling or manually (p < 0.001. Udder drying was only applied in peri-urban herds (100%. Herd level prevalence of mastitis was lower in smallholder than in pastoral herds (60.7% vs 93.3%. Mastitis positive samples had higher prevalence of S.aureus than of Streptococcus species in both smallholder (57.9% vs 23.7% and pastoral (41.6% vs 36.5% herds. Moreover, SCC was significantly affected by presence of mastitis and S.aureus (p < 0.001. Milk PHL from high SCC was higher in smallholder rural herds (27% compared to peri-urban (7% and in pastoral peri-urban (81% compared to rangelands (76%. Milking practices may have contributed to maintain mastitis pathogens in herds. This has led to substantial pre and postharvest milk losses in smallholder and pastoral herds. Therefore teat dipping, dry cow period and herd level mastitis treatment may complement current practices for lower SCC and milk PHL.

  12. Comparative proteomic and metabolomic profiling of citrus fruit with enhancement of disease resistance by postharvest heat treatment.

    Science.gov (United States)

    Yun, Ze; Gao, Huijun; Liu, Ping; Liu, Shuzhen; Luo, Tao; Jin, Shuai; Xu, Qiang; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2013-03-16

    postharvest citrus fruit, and gives new insights into HT improved fruit disease resistance during subsequent storage of 'Kamei' Satsuma mandarin. Interpretation of the data for the proteins and metabolites revealed reactive oxygen species (ROS) and lignin play important roles in heat treatment induced fruit resistance to pathogens and physiological disorders.

  13. Genome Sequence, Assembly and Characterization of Two Metschnikowia fructicola Strains Used as Biocontrol Agents of Postharvest Diseases

    Directory of Open Access Journals (Sweden)

    Edoardo Piombo

    2018-04-01

    Full Text Available The yeast Metschnikowia fructicola was reported as an efficient biological control agent of postharvest diseases of fruits and vegetables, and it is the bases of the commercial formulated product “Shemer.” Several mechanisms of action by which M. fructicola inhibits postharvest pathogens were suggested including iron-binding compounds, induction of defense signaling genes, production of fungal cell wall degrading enzymes and relatively high amounts of superoxide anions. We assembled the whole genome sequence of two strains of M. fructicola using PacBio and Illumina shotgun sequencing technologies. Using the PacBio, a high-quality draft genome consisting of 93 contigs, with an estimated genome size of approximately 26 Mb, was obtained. Comparative analysis of M. fructicola proteins with the other three available closely related genomes revealed a shared core of homologous proteins coded by 5,776 genes. Comparing the genomes of the two M. fructicola strains using a SNP calling approach resulted in the identification of 564,302 homologous SNPs with 2,004 predicted high impact mutations. The size of the genome is exceptionally high when compared with those of available closely related organisms, and the high rate of homology among M. fructicola genes points toward a recent whole-genome duplication event as the cause of this large genome. Based on the assembled genome, sequences were annotated with a gene description and gene ontology (GO term and clustered in functional groups. Analysis of CAZymes family genes revealed 1,145 putative genes, and transcriptomic analysis of CAZyme expression levels in M. fructicola during its interaction with either grapefruit peel tissue or Penicillium digitatum revealed a high level of CAZyme gene expression when the yeast was placed in wounded fruit tissue.

  14. Pathogen intelligence

    Directory of Open Access Journals (Sweden)

    Michael eSteinert

    2014-01-01

    Full Text Available Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behaviour, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behaviour, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies.

  15. The effect of ionizing irradiation on the postharvest quality of vegetables

    International Nuclear Information System (INIS)

    Morris, S.C.

    1985-01-01

    The widespread adoption of irradiation as a postharvest treatment must depend on superior performances with regard to product quality, economics, safety both during application and of the final product, and finally consumer acceptance

  16. Development of biocontrol agents from food microbial isolates for controlling post-harvest peach brown rot caused by Monilinia fructicola.

    Science.gov (United States)

    Zhou, Ting; Schneider, Karin E; Li, Xiu-Zhen

    2008-08-15

    An unconventional strategy of screening food microbes for biocontrol activity was used to develop biocontrol agents for controlling post-harvest peach brown rot caused by Monilinia fructicola. Forty-four microbial isolates were first screened for their biocontrol activity on apple fruit. Compared with the pathogen-only check, seven of the 44 isolates reduced brown rot incidence by >50%, including four bacteria: Bacillus sp. C06, Lactobacillus sp. C03-b and Bacillus sp. T03-c, Lactobacillus sp. P02 and three yeasts: Saccharomyces delbrueckii A50, S. cerevisiae YE-5 and S. cerevisiae A41. Eight microbial isolates were selected for testing on peaches by wound co-inoculation with mixtures of individual microbial cultures and conidial suspension of M. fructicola. Only two of them showed significant biocontrol activity after five days of incubation at 22 degrees C. Bacillus sp. C06 suppressed brown rot incidence by 92% and reduced lesion diameter by 88% compared to the pathogen-only check. Bacillus sp.T03-c reduced incidence and lesion diameter by 40% and 62%, respectively. The two isolates were compared with Pseudomonas syringae MA-4, a biocontrol agent for post-harvest peach diseases, by immersing peaches in an aliquot containing individual microbial isolates and the pathogen conidia. Treatments with isolates MA-4, C06 and T03-c significantly controlled brown rot by 91, 100, and 100% respectively. However, only isolates MA-4 and C06 significantly reduced brown rot by 80% and 15%, respectively when bacterial cells alone were applied. On naturally infected peaches, both the bacterial culture and its cell-free filtrate of the isolate C06 significantly controlled peach decay resulting in 77 and 90% reduction, respectively, whereas the treatment using only the bacterial cells generally had no effect. Isolate C06 is a single colony isolate obtained from a mesophilic cheese starter, and has been identified belonging to Bacillus amyloliquefaciens. The results have clearly

  17. Potential applications of ionizing radiation in postharvest handling of fresh fruits and vegetables

    International Nuclear Information System (INIS)

    Kader, A.A.

    1986-01-01

    The advantages and limitations of potential uses of ionizing radiation of harvested fresh fruits and vegetables are discussed. Potential applications include: sprout inhibition of tuber, bulb, and root vegetables; inhibition of post-harvest growth of asparagus and mushrooms; insect disinfestation; alteration of ripening and senescence in fresh fruits; and post-harvest microorganism disease control. Cost, consumer acceptance, and logistical problems are cited as possible limiting factors. Factors influencing response also are discussed

  18. Toward better understanding of postharvest deterioration: biochemical changes in stored cassava (Manihot esculenta Crantz) roots

    OpenAIRE

    Uarrota, Virgílio Gavicho; Nunes, Eduardo da Costa; Peruch, Luiz Augusto Martins; Neubert, Enilto de Oliveira; Coelho, Bianca; Moresco, Rodolfo; Garcia Domínguez, Moralba; Sánchez, Teresa; Luna Meléndez, Jorge Luis; Dufour, Dominique; Ceballos, Hernan; Becerra Lopez-Lavalle, Luis Augusto; Hershey, Clair; Rocha, Miguel; Maraschin, Marcelo

    2016-01-01

    Abstract Food losses can occur during production, postharvest, and processing stages in the supply chain. With the onset of worldwide food shortages, interest in reducing postharvest losses in cassava has been increasing. In this research, the main goal was to evaluate biochemical changes and identify the metabolites involved in the deterioration of cassava roots. We found that high levels of ascorbic acid (AsA), polyphenol oxidase (PPO), dry matter, and proteins are correlated with overall l...

  19. Comparison of buffalo rumen liquor and buffalo faeces as inoculum for the in vitro gas production technique

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    V. Piccolo

    2010-01-01

    Full Text Available The in vitro gas production technique (IVGPT, Theodorou et al., 1994 requires a rumen liquor (RL inoculum, as the other methods utilising a microbial fermentation approach to feedstuff evaluation. However, the RL is collected either from animals fitted with rumen cannula or at slaughtering. This raises a number of practical, economical and ethical problems, thus several studies have been carried out to test alternative inocula. To this aim faeces (FA have been demonstrated to have high potentiality for the Tilley and Terry (1963 technique (El Saher et al., 1987; Akther et al., 1999; Cone et al., 2002. Mauricio et al. (2001, evaluating the forages fermentative characteristics by IVGPT, found lower potential gas production and longer lag times for bovine FA compared to RL as inoculum. Aim of present paper was to compare buffalo RL and FA as inoculum for IVGPT.

  20. Effect of Selenium on Control of Postharvest Gray Mold of Tomato Fruit and the Possible Mechanisms Involved

    Science.gov (United States)

    Wu, Zhilin; Yin, Xuebin; Bañuelos, Gary S.; Lin, Zhi-Qing; Zhu, Zhu; Liu, Ying; Yuan, Linxi; Li, Miao

    2016-01-01

    Selenium (Se) has important benefits for crop growth and stress tolerance at low concentrations. However, there is very little information on antimicrobial effect of Se against the economically important fungus Botrytis cinerea. In the present study, using sodium selenite as Se source, we investigated the effect of Se salts on spore germination and mycelial growth of the fungal pathogen in vitro and gray mold control in harvested tomato fruit. Se treatment at 24 mg/L significantly inhibited spore germination of the fungal pathogen and effectively controlled gray mold in harvested tomato fruit. Se treatment at 24 mg/L seems to induce the generation of intracellular reactive oxygen species in the fungal spores. The membrane integrity damage was observed with fluorescence microscopy following staining with propidium iodide after treatment of the spores with Se. These results suggest that Se has the potential for controlling gray mold rot of tomato fruits and might be useful in integrated control against gray mold disease of postharvest fruits and vegetables caused by B. cinerea. The mechanisms by which Se decreased gray mold decay of tomato fruit may be directly related to the severe damage to the conidia plasma membrane and loss of cytoplasmic materials from the hyphae. PMID:26779128

  1. Effect of selenium on control of postharvest gray mould of tomato fruit and the possible mechanisms involved

    Directory of Open Access Journals (Sweden)

    Zhilin eWu

    2016-01-01

    Full Text Available Selenium (Se has important benefits for crop growth and stress tolerance at low concentrations. However, there is very little information on antimicrobial effect of selenium against the economically important fungus Botrytis cinerea. In the present study, using sodium selenite as Se source, we investigated the effect of Se salts on spore germination and mycelial growth of the fungal pathogen in vitro and gray mould control in harvested tomato fruit. Se treatment at 24 mg/L significantly inhibited spore germination of the fungal pathogen and effectively controlled gray mould in harvested tomato fruit. Se treatment at 24 mg/L seems to induce the generation of intracellular reactive oxygen species in the fungal spores. The membrane integrity damage was observed with fluorescence microscopy following staining with propidium iodide after treatment of the spores with Se. These results suggest that Se has the potential for controlling gray mould rot of tomato fruits and might be useful in integrated control against gray mould disease of postharvest fruits and vegetables caused by B. cinerea. The mechanisms by which Se decreased gray mould decay of tomato fruit may be directly related to the severe damage to the conidia plasma membrane and loss of cytoplasmic materials from the hyphae.

  2. Pre- and postharvest preventive measures and intervention strategies to control microbial food safety hazards of fresh leafy vegetables.

    Science.gov (United States)

    Gil, Maria I; Selma, Maria V; Suslow, Trevor; Jacxsens, Liesbeth; Uyttendaele, Mieke; Allende, Ana

    2015-01-01

    This review includes an overview of the most important preventive measures along the farm to fork chain to prevent microbial contamination of leafy greens. It also includes the technological and managerial interventions related to primary production, postharvest handling, processing practices, distribution, and consumer handling to eliminate pathogens in leafy greens. When the microbiological risk is already present, preventive measures to limit actual contamination events or pathogen survival are considered intervention strategies. In codes of practice the focus is mainly put on explaining preventive measures. However, it is also important to establish more focused intervention strategies. This review is centered mainly on leafy vegetables as the commodity identified as the highest priority in terms of fresh produce microbial safety from a global perspective. There is no unique preventive measure or intervention strategy that could be applied at one point of the food chain. We should encourage growers of leafy greens to establish procedures based on the HACCP principles at the level of primary production. The traceability of leafy vegetables along the chain is an essential element in ensuring food safety. Thus, in dealing with the food safety issues associated with fresh produce it is clear that a multidisciplinary farm to fork strategy is required.

  3. The contribution of the Institute of Sciences of Food Production of CNR in the postharvest scientific context

    International Nuclear Information System (INIS)

    Agabbio, M.

    2006-01-01

    The Institute of Sciences of Food Production of CNR (National Research Council) has been designated to perform scientific studies in the postharvest field; they mainly aim at extending the life of horticultural commodities, maintaining their quality during storage and limiting fruit losses during the marketing period. The scientific work of the Institute concerns fruit and vegetable products, both fresh and minimally transformed. Experimental research on these commodities aims at providing process parameters (temperature, relative humidity, atmosphere) to managers of packinghouses, in order to have efficient cold storage. Another research field regards pathogen control for the purpose of maintaining product healthiness and at the same time of avoiding environmental pollution. Particularly in this field, research on commonly used compounds and the screening of new ones in order to prevent pathogen diseases are carried out with International protocols, contemporarily with other Countries. Surveys are completed with wide-reaching studies on alternative systems such as physical methods (thermotherapy, UV rays, curing), biological control (essential oils and antagonist microorganisms) and with GRAS (Generally Recognized As Safe) compounds, harmless for the consumer and the environment. A great deal of research is carried out in order to examine physiological phenomena, particularly during ripening and senescence periods of the fruit and aspects connected with quality. In twenty-five years of activity, almost five hundred papers have been issued illustrating technological innovations [it

  4. Relation between ethyl alcohol production by Saccharomyces cerevisiae from Iraqi dates, pure sugar solution, and the amount of inoculum

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, N.D.; Al-Talibi, A.A.; Abboud, A.R.

    1975-01-01

    An experiment was initiated to investigate the production of ethyl alcohol using Zahdi data extraction and pure sugar (sucrose) solutions in different concentrations as media and S. cerevisiae as a starter. Through this investigation the following facts have been found: 0.5% ammonium phosphate as a source of nutrient was satisfactory, date extraction of 25% and inoculum of 12% gave the highest yield of ethyl alcohol; however 15% of pure sucose solution gave the maximum yield with a slight difference when compared with 20%; increasing the inoculum shortened the time of fermentation with no effect on inhibitory phenomenon; the rate of alcohol production was associated with the rate of yeast proliferation.

  5. The Study Of Metalworking Fluids Biodegradability By Indirect Measurement Of Bacterial Inoculum Respiration

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    Gerulová Kristína

    2015-06-01

    Full Text Available An apparatus for measuring biodegradability of metalworking fluids (MWFs was constructed according to (1, based on the Zahn-Wellens test which enables a continuous determination of CO2 production by the change in conductivity of absorption solution. Results obtained from the testing of 8 different MWFs by this modified method were compared to those obtained in standardized OECD 302 B. The comparison showed better description of bacterial inoculum activity in tested solution; lag phase was easy to indicate. Tested emulsion achieved the level of primary degradability 39.7 – 40.8 %, and semi-synthetics 19.1 – 43.5%. The samples of synthetics where the degradation level reached 43.9 - 58.6 % were identified as the most degradable metalworking fluids.

  6. Physical and textural characteristics of fermented milk products obtained by kombucha inoculums with herbal teas

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    Malbaša Radomir V.

    2012-01-01

    Full Text Available In this investigation, kombucha fermented milk products were produced from milk with 1.6% milk fat using 10% (v/v kombucha inoculums cultivated on the extracts of peppermint and stinging nettle. The fermentation process was conducted at temperatures of 37, 40 and 43°C. Fermentation was stopped when the pH value of 4.5 was reached. The fermentation process was shortened with an increase of temperature. Physical characteristics of the fermented products were determined by using standard methods of analysis. Textural characteristics were determined by texture profile analysis. The obtained products showed good physical and textural characteristics, typical for the yoghurt-like products. [Projekat Ministarstva nauke Republike Srbije, br. III-46009

  7. Correlation of the microstructure with viscosity and textural properties during milk fermentation by kombucha inoculum

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir R.

    2014-01-01

    Full Text Available The aim of this study was to examine the changes in the microstructure, textural properties and viscosity of the gel formed during milk fermentation with kombucha inoculum and to establish a relationship between the microstructure and these properties. The values of the analyzed characteristics were measured during the gelation at 42°C at the following pHs: 5.4, 5.1, 4.8 and 4.6. The microstructure analysis revealed disappearance of coarse cluster structure and appearance of finer casein micelles network during fermentation. The obtained results showed significant differences in them viscosity and textural properties during fermentation, which is in accordance with their microstructure. The correlation of the examined properties and microstructure of the gel was established. [Projekat Ministarstva nauke Republike Srbije, br. 46009

  8. Inoculum pretreatment affects bacterial survival, activity and catabolic gene expression during phytoremediation of diesel contaminated soil.

    Science.gov (United States)

    Khan, Sumia; Afzal, Muhammad; Iqbal, Samina; Mirza, Muhammad Sajjad; Khan, Qaiser M

    2013-04-01

    Plant-bacteria partnership is a promising approach for remediating soil contaminated with organic pollutants. The colonization and metabolic activity of an inoculated microorganism depend not only on environmental conditions but also on the physiological condition of the applied microorganisms. This study assessed the influence of different inoculum pretreatments on survival, gene abundance and catabolic gene expression of an applied strain (Pantoea sp. strain BTRH79) in the rhizosphere of ryegrass vegetated in diesel contaminated soil. Maximum bacterium survival, gene abundance and expression were observed in the soil inoculated with bacterial cells that had been pregrown on complex medium, and hydrocarbon degradation and genotoxicity reduction were also high in this soil. These findings propose that use of complex media for growing plant inocula may enhance bacterial survival and colonization and subsequently the efficiency of pollutant degradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Effect of ionic strength, cation exchanger and inoculum age on the performance of Microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, Yama; Das, Debabrata [Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302 (India)

    2009-09-15

    Power generation in Microbial fuel cells (MFCs) is a function of various physico-chemical as well as biological parameters. In this study, we have examined the effect of ionic strength, cation exchanger and inoculum age on power generation in a mediator MFC with methylene blue as electron mediator using Enterobacter cloacae IIT-BT08. The effect of ionic strength was studied using NaCl in the anode chamber of a two chambered salt-bridge MFC at concentrations of 5 mM, 10 mM and 15 mM. Maximum power density of 12.8 mW/m{sup 2} was observed when 10 mM NaCl was used. Corresponding current density was noted to be 35.5 mA/m{sup 2}. Effect of cation exchanger was observed by replacing salt-bridge with a proton exchange membrane of equal surface area. When the salt-bridge was replaced by a proton exchange membrane, a 3-fold increase in the power density was observed. Power density and current density of 37.8 mW/m{sup 2} and 110.3 mA/m{sup 2} respectively were detected. The influence of the pre-inoculum on the MFC was studied using E. cloacae IIT-BT08 grown for 12, 14, 16 and 18 h. It was observed that 16 h grown culture when inoculated in the anode chamber gave the maximum power output. Power density and current density of 68 mW/m{sup 2} and 168 mA/m{sup 2} respectively were obtained. We demonstrate from these results that both physico-chemical as well as biological parameters need to be optimized for improving the power generation in MFCs. (author)

  10. Effects of substrate to inoculum ratio on the biochemical methane potential of piggery slaughterhouse wastes.

    Science.gov (United States)

    Yoon, Young-Man; Kim, Seung-Hwan; Shin, Kook-Sik; Kim, Chang-Hyun

    2014-04-01

    The aim of this study was to assess the effect of substrate to inoculum ratio (S/I ratio) on the biochemical methane potential (BMP) and anaerobic biodegradability (Ddeg) of different piggery slaughterhouse wastes, such as piggery blood, intestine residue, and digestive tract content. These wastes were sampled from a piggery slaughterhouse located in Kimje, South Korea. Cumulative methane production curves for the wastes were obtained from the anaerobic batch fermentation having different S/I ratios of 0.1, 0.5, 1.0, and 1.5. BMP and anaerobic biodegradabilities (Ddeg) of the wastes were calculated from cumulative methane production data for the tested conditions. At the lowest S/I ration of 0.1, BMPs of piggery blood, intestine residue, and digestive tract content were determined to be 0.799, 0.848, and 1.076 Nm(3) kg(-1)-VSadded, respectively, which were above the theoretical methane potentials of 0.539, 0.644, and 0.517 Nm(3) kg(-1)-VSadded for blood, intestine residue, and digestive tract content, respectively. However, BMPs obtained from the higher S/I ratios of 0.5, 1.0, and 1.5 were within the theoretical range for all three types of waste and were not significantly different for the different S/I ratios tested. Anaerobic biodegradabilities calculated from BMP data showed a similar tendency. These results imply that, for BMP assay in an anaerobic reactor, the S/I ratio of anaerobic reactor should be above 0.1 and the inoculum should be sufficiently stabilized to avoid further degradation during the assay.

  11. Effects of Substrate to Inoculum Ratio on the Biochemical Methane Potential of Piggery Slaughterhouse Wastes

    Directory of Open Access Journals (Sweden)

    Young-Man Yoon

    2014-04-01

    Full Text Available The aim of this study was to assess the effect of substrate to inoculum ratio (S/I ratio on the biochemical methane potential (BMP and anaerobic biodegradability (Ddeg of different piggery slaughterhouse wastes, such as piggery blood, intestine residue, and digestive tract content. These wastes were sampled from a piggery slaughterhouse located in Kimje, South Korea. Cumulative methane production curves for the wastes were obtained from the anaerobic batch fermentation having different S/I ratios of 0.1, 0.5, 1.0, and 1.5. BMP and anaerobic biodegradabilities (Ddeg of the wastes were calculated from cumulative methane production data for the tested conditions. At the lowest S/I ration of 0.1, BMPs of piggery blood, intestine residue, and digestive tract content were determined to be 0.799, 0.848, and 1.076 Nm3 kg−1-VSadded, respectively, which were above the theoretical methane potentials of 0.539, 0.644, and 0.517 Nm3 kg−1-VSadded for blood, intestine residue, and digestive tract content, respectively. However, BMPs obtained from the higher S/I ratios of 0.5, 1.0, and 1.5 were within the theoretical range for all three types of waste and were not significantly different for the different S/I ratios tested. Anaerobic biodegradabilities calculated from BMP data showed a similar tendency. These results imply that, for BMP assay in an anaerobic reactor, the S/I ratio of anaerobic reactor should be above 0.1 and the inoculum should be sufficiently stabilized to avoid further degradation during the assay.

  12. Postharvest application of a novel chitinase cloned from Metschnikowia fructicola and overexpressed in Pichia pastoris to control brown rot of peaches.

    Science.gov (United States)

    Banani, Houda; Spadaro, Davide; Zhang, Dianpeng; Matic, Slavica; Garibaldi, Angelo; Gullino, Maria Lodovica

    2015-04-16

    Metschnikowia fructicola strain AP47 is a yeast antagonist against postharvest pathogens of fruits. The yeast was able to produce chitinase enzymes in the presence of pathogen cell wall. A novel chitinase gene MfChi (GenBank accession number HQ113461) was amplified from the genomic DNA of Metschnikowia fructicola AP47. Sequence analysis showed lack of introns, an open reading frame (ORF) of 1098 bp encoding a 365 amino acid protein with a calculated molecular weight of 40.9 kDa and a predicted pI of 5.27. MfChi was highly induced in Metschnikowia fructicola after interaction with Monilinia fructicola cell wall, suggesting a primary role of MfChi chitinase in the antagonistic activity of the yeast. The MfChi gene overexpressed in the heterologous expression system of Pichia pastoris KM71 and the recombinant chitinase showed high endochitinase activity towards 4-Nitrophenyl β-d-N,N',N″-triacetylchitotriose substrate. The antifungal activity of the recombinant chitinase was investigated against Monilinia fructicola and Monilinia laxa in vitro and on peaches. The chitinase significantly controlled the spore germination and the germ tube length of the tested pathogens in PDB medium and the mycelium diameter in PDA. The enzyme, when applied on peaches cv. Redhaven, successfully reduced brown rot severity. This work shows that the chitinase MfChi could be developed as a postharvest treatment with antimicrobial activity for fruit undergoing a short shelf life, and confirms that P. pastoris KM71 is a suitable microorganism for cost-effective large-scale production of recombinant chitinases. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. PATHOGENICITY OF FUSARIUM SPP. ISOLATED FROM WEEDS AND PLANT DEBRIS IN EASTERN CROATIA TO WHEAT AND MAIZE

    Directory of Open Access Journals (Sweden)

    Jelena Ilić

    2012-12-01

    Full Text Available Pathogenicity of thirty isolates representing 14 Fusarium species isolated from weeds and plant debris in eastern Croatia was investigated in the laboratory. Pathogenicity tests were performed on wheat and maize seedlings. The most pathogenic Fusarium spp. was F. graminearum isolated from Amaranthus retroflexus, Abutilon theophrasti and Chenopodium album. There was a noticeable inter- and intraspecies variability in pathogenicity towards wheat and maize. Isolates of F. solani from Sonchus arvensis and F. verticillioides from C. album were highly pathogenic to wheat seedlings and apathogenic to maize seedlings. Isolates of F. venenatum were very pathogenic to wheat and maize being the first report about pathogenicity of this species. This experiment proves that weeds and plant debris can serve as alternate hosts and source of inoculum of plant pathogens.

  14. Hydrogen sulfide prolongs postharvest storage of fresh-cut pears (Pyrus pyrifolia by alleviation of oxidative damage and inhibition of fungal growth.

    Directory of Open Access Journals (Sweden)

    Kang-Di Hu

    Full Text Available Hydrogen sulfide (H2S has proved to be a multifunctional signaling molecule in plants and animals. Here, we investigated the role of H2S in the decay of fresh-cut pears (Pyrus pyrifolia. H2S gas released by sodium hydrosulfide (NaHS prolonged the shelf life of fresh-cut pear slices in a dose-dependent manner. Moreover, H2S maintained higher levels of reducing sugar and soluble protein in pear slices. H2S significantly reduced the accumulation of hydrogen peroxide (H2O2, superoxide radicals (•O2(- and malondialdehyde (MDA. Further investigation showed that H2S fumigation up-regulated the activities of antioxidant enzymes ascorbate peroxidase (APX, catalase (CAT, and guaiacol peroxidase (POD, while it down-regulated those of lipoxygenase (LOX, phenylalanine ammonia lyase (PAL and polyphenol oxidase (PPO. Furthermore, H2S fumigation effectively inhibited the growth of two fungal pathogens of pear, Aspergillus niger and Penicillium expansum, suggesting that H2S can be developed as an effective fungicide for postharvest storage. The present study implies that H2S is involved in prolonging postharvest storage of pears by acting as an antioxidant and fungicide.

  15. Salicylic acid treatment reduces the rot of postharvest citrus fruit by inducing the accumulation of H2O2, primary metabolites and lipophilic polymethoxylated flavones.

    Science.gov (United States)

    Zhu, Feng; Chen, Jiajing; Xiao, Xue; Zhang, Mingfei; Yun, Ze; Zeng, Yunliu; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2016-09-15

    To comprehensively analyze the effects of salicylic acid (SA) on the storability of Satsuma mandarin (Citrus unshiu), fruits were treated with 2mM SA. The disease incidence of control/SA-treated fruit at 50d and 120d after treatment was 23.3%/10% and 67.3%/23.3%, respectively, suggesting that SA treatment can significantly reduce the rot rate of postharvest citrus fruit. Fruit quality assays revealed that the treatment can maintain fruit firmness without affecting the inner quality. Furthermore, the contents of H2O2 and some defense-related metabolites, such as ornithine and threonine, in citrus pericarp, were significantly increased by SA treatment. Moreover, it was lipophilic polymethoxylated flavones, rather than flavanone glycosides, that accumulated in SA-treated fruits and these can directly inhibit pathogen development. These results suggest that the effects of SA on postharvest citrus fruit may be attributed to the accumulation of H2O2 and defense-related metabolites. Copyright © 2016. Published by Elsevier Ltd.

  16. Using Reduced Inoculum Densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to Prevent False-Resistant Results and Improve Accuracy: A Multicenter Evaluation

    Directory of Open Access Journals (Sweden)

    Glenn P. Morlock

    2017-01-01

    Full Text Available The primary platform used for pyrazinamide (PZA susceptibility testing of Mycobacterium tuberculosis is the MGIT culture system (Becton Dickinson. Since false-resistant results have been associated with the use of this system, we conducted a multicenter evaluation to determine the effect of using a reduced cell density inoculum on the rate of false resistance. Two reduced inoculum densities were compared with that prescribed by the manufacturer (designated as “BD” method. The reduced inoculum methods (designated as “A” and “C” were identical to the manufacturer’s protocol in all aspects with the exception of the cell density of the inoculum. Twenty genetically and phenotypically characterized M. tuberculosis isolates were tested in duplicate by ten independent laboratories using the three inoculum methods. False-resistant results declined from 21.1% using the standard “BD” method to 5.7% using the intermediate (“A” inoculum and further declined to 2.8% using the most dilute (“C” inoculum method. The percentages of the resistant results that were false-resistant declined from 55.2% for the “BD” test to 28.8% and 16.0% for the “A” and “C” tests, respectively. These results represent compelling evidence that the occurrence of false-resistant MGIT PZA susceptibility test results can be mitigated through the use of reduced inoculum densities.

  17. On-farm production of arbuscular mycorrhizal funus inoculum in compost and vermiculite mixtures: results of on-farm demonstrations and impact of compost microbiological quality

    Science.gov (United States)

    The sustainability and profitability of many agricultural systems can be enhanced through the utilization of inoculum of arbuscular mycorrhizal fungi. Inocula are commercially available, but inoculum can also be produced on-farm in mixtures of compost and vermiculite with a nurse host plant. Demon...

  18. Effects of Phytophthora cinnamomi isolate, inoculum delivery method, flood, and drought on vigor, disease severity and mortality of blueberry plants

    Science.gov (United States)

    Four studies evaluated the effect of Phytophthora cinnamomi isolates, inoculum delivery methods, and flood and drought conditions on vigor, disease severity scores, and survival of blueberry plants grown in pots in the greenhouse. Phytophthora cinnamomi isolates were obtained from blueberry plants ...

  19. Effects of sludge inoculum and organic feedstock on active microbial communities and methane yield during anaerobic digestion

    Directory of Open Access Journals (Sweden)

    David eWilkins

    2015-10-01

    Full Text Available Anaerobic digestion (AD is a widespread microbial technology used to treat organic waste and recover energy in the form of methane (biogas. While most AD systems have been designed to treat a single input, mixtures of digester sludge and solid organic waste are emerging as a means to improve efficiency and methane yield. We examined laboratory anaerobic cultures of AD sludge from two sources amended with food waste, xylose, and xylan at mesophilic temperatures, and with cellulose at meso- and thermophilic temperatures, to determine whether and how the inoculum and substrate affect biogas yield and community composition. All substrate and inoculum combinations yielded methane, with food waste most productive by mass. Pyrosequencing of transcribed bacterial and archaeal 16S rRNA showed that community composition varied across substrates and inocula, with differing ratios of hydrogenotrophic/acetoclastic methanogenic archaea associated with syntrophic partners. While communities did not cluster by either inoculum or substrate, additional sequencing of the bacterial 16S rRNA gene in the source sludge revealed that the bacterial communities were influenced by their inoculum. These results suggest that complete and efficient AD systems could potentially be assembled from different microbial inocula and consist of taxonomically diverse communities that nevertheless perform similar functions.

  20. Chemical disinfection of non-porous inanimate surfaces experimentally contaminated with four human pathogenic viruses.

    OpenAIRE

    Sattar, S. A.; Springthorpe, V. S.; Karim, Y.; Loro, P.

    1989-01-01

    The chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenza virus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 microliter amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were...

  1. Gamma radiation effects on physico-chemical parameters of apple fruit during commercial post-harvest preservation

    International Nuclear Information System (INIS)

    Mostafavi, Hossein Ahari; Mirmajlessi, Seyed Mahyar; Mirjalili, Seyed Mohammad; Fathollahi, Hadi; Askari, Hadi

    2012-01-01

    The physico-chemical parameters (including moisture, total soluble solids, antioxidant activity, phenolic content and firmness) of cv. Red Delicious apple subjected to γ radiation were evaluated for their ability to avoid the post-harvest blue mold caused by Penicillium expansum during cold storage. Freshly harvested apples were inoculated with P. expansum. Treated fruits were irradiated at doses of 0, 300, 600, 900 and 1200 Gy and stored at 1 °C. Apples were evaluated at three month intervals. The results showed that there was a clear link between phenolic content and antioxidant activity, so that dose range of 900 Gy and higher significantly decreased phenolic content and antioxidant activity. The moisture percent of stored apples was more responsive to irradiation (at doses of 900–1200 Gy) than storage time and pathogen. Lesion diameter of pathogen-treated non-irradiated apples was significantly increased after three months. This means that storage at low temperature is not enough to avoid blue mold growth. As dose and storage time increased firmness decreased; also pathogen accelerated softening of stored apples. This study showed conclusively that low irradiation doses (300 and 600 Gy) combined with cold storage is a way to minimize apple quality losses during nine month storage period. - Highlights: ► A suitable method to reduce apple quality losses during nine month storage period. ► Effects of γ radiation and cold storage on physico-chemical parameters of the apple. ► Potential dual benefit of low irradiation dose combined with cold storage. ► Radiation dose determination for Penicillium expansum control.

  2. Postharvest storage quality of gamma-irradiated 'climax' rabbiteye blueberries

    International Nuclear Information System (INIS)

    Miller, W.R.; Mitcham, E.J.; McDonald, R.E.; King, J.R.

    1994-01-01

    Postharvest quality of 'Climax' rabbiteye blueberries (Vaccinium ashei Read) was evaluated after exposure to dosages of 0, 0.75,1.5,2.25, or 3.0 kGy gamma irradiation (0.1 18 kGy-min-1) and after subsequent storage. Irradiation did not affect weight loss, but irradiated berries were softer than nontreated berries. There was also a trend toward increased decay as dose increased. Irradiation had no effect on powdery bloom or surface color; total soluble solids concentration, acidity, and pH were affected slightly. Flavor preference was highest for nonirradiated berries and generally declined as dosage increased. Irradiation at 2.25 and 3.0 kGy resulted in increased levels of xylosyl residues in cell walls, and xylosyl residues were the most abundant cell-wall neutral sugar detected in blueberries. There was no evidence of cell wall pectin loss in irradiated berries. Irradiation at 1.5 kGy lowered the quality of fresh-market 'Climax' blueberries

  3. Postharvest technologies for mangosteen (Garcinia mangostana L. conservation

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Pontes Penteado Moretzsohn de Castro

    2012-12-01

    Full Text Available The application of technologies to extend the postharvest life of mangosteen fruit was studied and compared to storage at 25 °C/70-75%R.H (25 °C control treatment. The fruits were packed in expanded polystyrene (EPS trays (5 fruits/tray. Five treatments were carried out at 13 °C/ 90-95% RH: application of carnauba wax coating, lecithin + CMC (carboxymethyl cellulose coating, 50 µm LDPE (low density polyethylene film coating, 13 µm PVC (Polyvinyl chloride, and non-coated sample (13 °C control treatment. Physicochemical analyses were performed twice a week. A statistical design was completely randomized with 8 repetitions for each treatment plus the control treatment. The results were submitted to variance analysis, and the averages compared by the Tukey test at 5% probability. Among the quality parameters analyzed, more significant differences were observed for weight loss, texture, and peel moisture content. The results showed that the maximum storage period for mangosteen at 25 °C is two weeks; while storage at13 °C can guarantee the conservation of this fruit for 25 days. Therefore, the treatment at 13 °C/90-95% RH without the use of coatings and films was more effective and economical.

  4. Postharvest internal browning of pineapple fruit originates at the phloem.

    Science.gov (United States)

    Luengwilai, Kietsuda; Beckles, Diane M; Siriphanich, Jingtair

    2016-09-01

    A typical symptom of postharvest chilling injury (PCI) in pineapple fruit (Ananas comosus (L.) Merr.) is internal browning (IB) near the fruit core. Since vascular bundles (VBs) are localized to this region, it was hypothesized that the VBs might be the site of IB. To test this, the anatomy and histochemistry of VBs during chilling stress in four pineapple cultivars with different levels of sensitivity to PCI were examined. Fruit were stored at 10°C for up to three weeks to stimulate translucency symptoms (TS; the initiation of IB). After three weeks of chilling exposure, the cultivars 'MD2' showed 0%, 'Pattavia' and 'Savee' showed 10-16%, and 'Trad Sri Thong' showed 100% TS and IB symptom. Scanning electron microscopy and in situ histochemical staining techniques that detect enzymes and substrates commonly associated with IB initiation were used in parallel. The TS of pineapple fruit coincided with the collapse of the phloem tissue. The VBs in the tissue where IB was initiated (i.e., the flesh adjacent to the core or F/C) had the highest activity of polyphenol oxidase, hydrogen peroxide, and phenolic compounds. The IB-resistant 'MD2' genotype had fewer VBs, but a greater proportion of sclerenchyma fibers (Ppineapple IB occurrence in the phloem was proposed. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Foodborne pathogens

    Directory of Open Access Journals (Sweden)

    Thomas Bintsis

    2017-06-01

    Full Text Available Foodborne pathogens are causing a great number of diseases with significant effects on human health and economy. The characteristics of the most common pathogenic bacteria (Bacillus cereus, Campylobacter jejuni, Clostridium botulinum, Clostridium perfringens, Cronobacter sakazakii, Esherichia coli, Listeria monocytogenes, Salmonella spp., Shigella spp., Staphylococccus aureus, Vibrio spp. and Yersinia enterocolitica, viruses (Hepatitis A and Noroviruses and parasites (Cyclospora cayetanensis, Toxoplasma gondii and Trichinella spiralis, together with some important outbreaks, are reviewed. Food safety management systems based on to classical hazard-based approach has been proved to be inefficient, and risk-based food safety approach is now suggested from leading researchers and organizations. In this context, a food safety management system should be designed in a way to estimate the risks to human health from food consumption and to identify, select and implement mitigation strategies in order to control and reduce these risks. In addition, the application of suitable food safety education programs for all involved people in the production and consumption of foods is suggested.

  6. Evaluation of sulfur dioxide-generating pads and modified atmosphere packaging for control of postharvest diseases in blueberries

    Science.gov (United States)

    Postharvest diseases are a limiting factor of storage and shelf life of blueberries. Gray mold caused by Botrytis cinerea is one of the most important postharvest diseases in blueberries grown in California. In this study, we evaluated the effects of sulfur dioxide (SO2)-generating pads (designated ...

  7. Effects of pre-and postharvest lighting on quality and shelf life of fresh-cut lettuce

    NARCIS (Netherlands)

    Woltering, E.J.; Witkowska, I.M.

    2016-01-01

    The effects of pre-and postharvest lighting on quality and shelf life of fresh-cut lettuce was investigated. Lettuce was grown under different light intensities (120 and 250 μmol m-2 s-1 PAR from fluorescent tubes) and quality at harvest and subsequent postharvest

  8. Chitosan-limonene coating in combination with modified atmosphere packaging preserve postharvest quality of cucumber during storage

    NARCIS (Netherlands)

    Maleki, Gisoo; Sedaghat, Naser; Woltering, Ernst J.; Farhoodi, Mehdi; Mohebbi, Mohebbat

    2018-01-01

    Since cucumbers suffer from a short postharvest life, applying different technologies is increasingly used as effective ways to increase their shelf life and quality. In this study a combination of chitosan-limonene coating and MAP storage has been used as a postharvest treatment to maintain

  9. Influence of postharvest processing and storage conditions on key antioxidants in pūhā (Sonchus oleraceus L.)

    DEFF Research Database (Denmark)

    Ou, Zong-Quan; Schmierer, David M; Strachan, Clare J

    2014-01-01

    To investigate effects of different postharvest drying processes and storage conditions on key antioxidants in Sonchus oleraceus L. leaves.......To investigate effects of different postharvest drying processes and storage conditions on key antioxidants in Sonchus oleraceus L. leaves....

  10. Solidago canadensis L. Essential Oil Vapor Effectively Inhibits Botrytis cinerea Growth and Preserves Postharvest Quality of Strawberry as a Food Model System.

    Science.gov (United States)

    Liu, Shumin; Shao, Xingfeng; Wei, Yanzhen; Li, Yonghua; Xu, Feng; Wang, Hongfei

    2016-01-01

    This study investigated the anti-fungal properties of Solidago canadensis L. essential oil (SCLEO) against Botrytis cinerea in vitro, and its ability to control gray mold and maintain quality in strawberry fruits. SCLEO exhibited dose-dependent antifungal activity against B. cinerea and profoundly altered mycelial morphology, cellular ultrastructure, and membrane permeability as evaluated by scanning electron microscopy, transmission electron microscopy, and fluorescence microscopy. SCLEO vapor at 0.1 mL/L maintained higher sensory acceptance and reduced decay of fresh strawberry fruit, and also reduced gray mold in artificially inoculated fruit. SCLEO treatment did not, however, stimulate phenylalanin ammonia-lyase, polyphenol oxidase, or chitinase, enzymes related to disease resistance. This suggests that SCLEO reduces gray mold by direct inhibition of pathogen growth. SCLEO vapor may provide a new and effective strategy for controlling postharvest disease and maintaining quality in strawberries.

  11. Solidago canadensis L essential oil vapor effectively inhibits Botrytis cinerea growth and preserves postharvest quality of strawberry as a food model system

    Directory of Open Access Journals (Sweden)

    Shumin Liu

    2016-08-01

    Full Text Available This study investigated the anti-fungal properties of Solidago canadensis L essential oil (SCLEO against Botrytis cinerea in vitro, and its ability to control gray mold and maintain quality in strawberry fruits. SCLEO exhibited dose-dependent antifungal activity against B. cinerea and profoundly altered mycelial morphology, cellular ultrastructure, and membrane permeability as evaluated by scanning electron microscopy, transmission electron microscopy, and fluorescence microscopy. SCLEO vapor at 0.1 mL/L maintained higher sensory acceptance and reduced decay of fresh strawberry fruit, and also reduced gray mold in artificially inoculated fruit. SCLEO treatment did not however, stimulate phenylalanin ammonia-lyase (PAL, polyphenol oxidase (POD, or chitinase (CHI, enzymes related to disease resistance. This suggests that SCLEO reduces gray mold by direct inhibition of pathogen growth. SCLEO vapor may provide a new and effective strategy for controlling postharvest disease and maintaining quality in strawberries.

  12. Post-harvest conservation of organic strawberries coated with cassava starch and chitosan

    Directory of Open Access Journals (Sweden)

    Raquel P Campos

    2011-10-01

    Full Text Available The strawberry is as non-climacteric fruit, but has a high post-harvest respiration rate, which leads to a rapid deterioration at room temperature. This study aimed to evaluate the application of biodegradable coating on postharvest conservation of organic strawberries, cv. Camarosa, packed in plastic hinged boxes and stored at 10ºC. The treatments consisted of: a control; b 2% cassava starch; c 1% chitosan; and d 2% cassava starch + 1% chitosan. Physical and chemical characteristics of fruits were evaluated at 3, 6 and 9 days of storage, and microbiological and sensory analyses were carried out at the end of the storage period. The treatments influenced positively the post-harvest quality of organic strawberries. The coating cassava starch + chitosan provided the best results, with less than 6% of loss in fruit mass, lower counts of yeast and psychrophilic microorganisms and the best appearance according to the sensory analysis.

  13. Apple biological and physiological disorders in the orchard and in postharvest according to production system

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Martins

    2013-03-01

    Full Text Available The study aimed to evaluate the incidence of biological and physiological disorders in the field and postharvested apples cvs. Gala, Fuji and Catarina grown in four production systems: conventional, organic transition, integrated and organic. Apples were evaluated for damages related to biological and physiological disorders in the orchard and after harvest. The greatest damages were attributed to pests, especially Anastrepha fraterculus in the organic system and Grapholita molesta in the organic transition. Apples produced in organic orchards had higher damage levels caused by postharvest physiological disorders than those grown in other production systems. For apples becoming from organic orchards most of the damage was due to lenticels breakdown and degeneration ('Gala', and bitter pit ('Fuji' and 'Catarina'. The incidence of postharvest rot was not influenced by apple production system.

  14. Decomposition of corn and soybean residues under field conditions and their role as inoculum source

    Directory of Open Access Journals (Sweden)

    E.M. Reis

    2011-03-01

    Full Text Available Necrotrophic parasites of above-ground plant parts survive saprophytically, between growing seasons in host crop residues. In an experiment conducted under field conditions, the time required in months for corn and soybean residues to be completely decomposed was quantified. Residues were laid on the soil surface to simulate no-till farming. Crop debris of the two plant species collected on the harvesting day cut into pieces of 5.0cm-long and a 200g mass was added to nylon mesh bags. At monthly intervals, bags were taken to the laboratory for weighing. Corn residues were decomposed within 37.0 months and those of soybean, within 34.5 months. Hw main necrotrophic fungi diagnosed in the corn residues were Colletotrichum gramicola, Diplodia spp. and Gibberella zeae, and those in soybeans residues were Cercospora kikuchii, Colletotrichum spp, Glomerella sp. and Phomopsis spp. Thus, those periods shoulb be observed in crop rotation aimed at to eliminating contaminated residues and, consequently, the inoculum from the cultivated area.

  15. Sterilization of Carriers by using Gamma Irradiation for Bio fertilizer Inoculum Production

    International Nuclear Information System (INIS)

    Tittabutr, Panlada; Teamtisong, Kamonluck; Pewlong, Wachiraporn; Teaumroong, Neuhg; Laoharojanaphand, Sirinart; Boonkerd, Nantakorn

    2009-07-01

    Full text: Gamma irradiation has been widely used in sterilization process, which leads to improvement in the quality of the products. In the case of bio fertilizer inoculum, the sterilized carrier is also needed for producing high quality bio fertilizer. This study aimed at determining the factors, such as carrier materials, moistures, and packing sizes including packaging materials that may affect the sterilization efficiency by using gamma irradiation. All carrier materials, peat and compost, could be efficiently sterilized by irradiation. The carriers that have moisture content lower than 20% could be sterilized by irradiation at 15 kGy, while carrier with 30% moisture content must be sterilized by irradiation at 25 kGy. Higher irradiation dose was also necessary for sterilization of bigger carrier packing sizes. For, packaging materials, polyethylene bag appeared most durable after gamma irradiation even at high doses. However, contaminants could be detected in irradiated carrier after storage at room temperature for two months. It was hypothesized that these contaminants are spore forming microorganisms, which resist gamma irradiation. This hypothesis, as well as the quality of bio fertilizer produced from irradiated carrier, will be further evaluated

  16. Bacterial inoculum enhances keratin degradation and biofilm formation in poultry compost.

    Science.gov (United States)

    Ichida, J M; Krizova, L; LeFevre, C A; Keener, H M; Elwell, D L; Burtt, E H

    2001-11-01

    Native microbial populations can degrade poultry waste, but the process can be hastened by using feather-degrading bacteria. Strains of Bacillus licheniformis and a Streptomyces sp. isolated from the plumage of wild birds were grown in a liquid basal medium and used to inoculate feathers in compost bioreaction vessels. Control vessels had only basal medium added to the feathers, litter and straw. Temperature, ammonia, carbon and nitrogen were monitored for 4 weeks. Scanning electron microscopy of the feather samples showed more complete keratin-degradation, more structural damage, and earlier microbial biofilm formation on inoculated feathers than on uninoculated feathers. A diverse community of aerobic bacteria and fungi were cultured early, but declined rapidly. Thermophilic B. licheniformis and Streptomyces spp. were abundant throughout. Enteric gram-negative bacteria, (e.g., Salmonella, E. coli) originally found on waste feathers were not recovered after day 4. Vessel temperatures reached 64-71 degrees C within 36 h and stabilized at 50 degrees C. When tumble-mixed at day 14, renewed activity peaked at 59 degrees C and quickly dropped as available carbon was used. Feathers soaked in an inoculum of B. licheniformis and Streptomyces degraded more quickly and more completely than feathers that were not presoaked. Inoculation of feather waste could improve composting of the large volume of feather waste generated every year by poultry farms and processing plants.

  17. Effects of chlorogenic acid on capacity of free radicals scavenging and proteomic changes in postharvest fruit of nectarine.

    Directory of Open Access Journals (Sweden)

    Yu Xi

    Full Text Available To study how chlorogenic acid affects changes of reactive oxygen species (ROS and the proteins involved in ROS scavenging of nectarine during storage time, the fruits were treated with chlorogenic acid (CHA then stored at 25°C for further studies. The CHA-treatment significantly reduced O2-· production rate, H2O2 content, and membrane permeability of nectarine fruit during storage. The key proteins related the nectarine fruit senescence during storage were identified by two-dimensional electrophoresis and MALDI-TOF/TOF. Level and enzymatic activity of peroxidase were reduced, while both the protein levels and the enzymatic activities of superoxide dismutase, glutathione reductase, glutathione-s-transferase and monodehydroascorbate reductase were enhanced in nectarine fruit treated with CHA. In addition, levels of several pathogen-related proteins were also enhanced by CHA-treatment. Taking together, the present study showed that CHA could influence changes in defense related proteins and reduced oxidative damage in nectarine fruit during postharvest ripening.

  18. Effect of Carbon Monoxide on Active Oxygen Metabolism of Postharvest Jujube

    OpenAIRE

    Shaoying Zhang; Qin Li; Yulan Mao

    2014-01-01

    To prolong the shelf life postharvest jujube, the effect of carbon monoxide (CO) on senescence of postharvest jujube in relation to active oxygen metabolism was investigated. Jujubes were fumigated with CO gas at 5, 10, 20 or 40μmol/L for 1 h, and then stored for 30 days at room temperature. Changes in membrane permeability, malonaldehyde (MDA), H2O2, O2•− content, and activities of active oxygen metabolism associated enzymes including superoxide dismutase (SOD), catalase (CAT) and peroxidase...

  19. Effects of differents gamma radiation doses absorbed for postharvest tomato fruits

    International Nuclear Information System (INIS)

    Silva Abreu, Toneypson da; Jesus, Edgar F.O. de; Soares, Antonio G.

    1997-01-01

    Postharvest tomato fuits Santa Cruz were submitted to prestorage gamma irradiation treatment with different doses range zero (unirradiated fruits) to 1000 Gy. The aim of this study is to evaluate the postharvest quality parameters: Hunter colour values for light transmittance analysis, pH, total titratable acidity, total soluble solids, maximum firmness and maturity stage. The fruits were stored under (25±1) 0 C with (93±3) relative humidity. The results obtained from the different irradiated treatments showed 600 Gy as the best dose to increase the shelf-life of tomato fruits and to decay its ripening. (author). 5 refs., 12 figs., 1 tab

  20. Propolis extract in postharvest conservation Solo papaya cv. 'Golden'

    Directory of Open Access Journals (Sweden)

    Flávia Regina Passos

    2016-12-01

    Full Text Available The high perishability of papaya (Carica papaya L. reduces its lifespan as well as limits marketing. Coating the fruits is an alternative to aid food preservation. We aimed to evaluate the effects of coating propolis extract on the physicochemical characteristics of papaya stored at room temperature. Solo papayas cv. 'Golden' were randomly divided into five postharvest treatment groups, three forms of dip-coating (70% alcohol, hydroalcoholic extract of propolis to 2.5%, and hydroalcoholic extract of propolis to 5% and two controls (one uncoated and one with refrigerated uncoated fruits. The weight loss, firmness, soluble solids (SS, titratable acidity (TA, SS/TA, and hydrogen potential (pH were evaluated at the intervals of 4 days every 12th storage day. Sensory analysis was performed on the 4th day of storage of papayas and evaluated by untrained through the acceptance testing. Treatments “refrigerated”, “propolis 2.5%”, and “5% propolis” presented with the lowest weight loss. The firmness level for treatment propolis 5% was superior to that of control, alcohol, and 2.5% propolis treatments. The SS was greater for propolis 5% treatment, which only differed from the alcohol treatment. The TA and SS/TA did not vary with the treatments, but with the storage time. The pH of refrigerated papaya showed significant differences in relation to other treatments. The fruits subjected to refrigerated treatment presented with chilling injury. Papayas coated with propolis extract showed sensory acceptability similar to that in other treatments on the 4th day of storage. The coating of propolis extract is a promising alternative for the control of weight loss and for the maintenance of firmness in Solo papaya cv. 'Golden'.

  1. Microbial Production of Xylitol from Oil Palm Empty Fruit Bunch Hydrolysate: Effects of Inoculum and pH

    Directory of Open Access Journals (Sweden)

    M.T.A.P. Kresnowati

    2016-11-01

    Full Text Available Considering its high content of hemicellulose, oil palm empty fruit bunch (EFB lignocellulosic biomass waste from palm oil processing has the potential to be utilized as the raw material for the production of xylitol, a low calorie, low GI, and anti cariogenic alternative sugar with similar sweetness to sucrose. This research explored the possibility of converting EFB to xylitol via green microbial fermentation, in particular the effects of inoculum and initial pH on the fermentation performance. It was observed that the cell concentration in the inoculum and the initial pH affect cell growth and xylitol production. pH 5 was observed to give the best fermentation performance. Further, the fermentation tended to yield more xylitol at higher initial cell concentration. It was also observed that no growth or fermentation inhibitory compounds were found in the EFB hydrolysate obtained from enzymatic hydrolysis of EFB. Thus it can be used directly as substrate for xylitol fermentation.

  2. Influence of physiological state of inoculum on volatile acidity production by Saccharomyces cerevisiae during high sugar fermentation

    Directory of Open Access Journals (Sweden)

    Marina Bely

    2005-12-01

    Full Text Available An approach consisting of controlling yeast inoculum to minimize volatile acidity production by Saccharomyces cerevisiae during the alcoholic fermentation of botrytized must was investigated. Direct inoculation of rehydrated active dry yeasts produced the most volatile acidity, while a yeast preparation pre-cultured for 24 hours reduced the final production by up to 23 %. Using yeasts collected from a fermenting wine as a starter must also reduced volatile acidity production. The conditions for preparing the inoculum affected the fermentation capacity of the first generation yeasts: fermentation duration, sugar to ethanol ratio, and wine composition. A pre-culture medium with a low sugar concentration (< 220 g/L is essential to limit volatile acidity production in high sugar fermentations.

  3. Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements

    Science.gov (United States)

    Zbrun, María V.; Soto, Lorena P.; Bertozzi, Ezequiel; Sequeira, Gabriel J.; Marti, Luis E.; Signorini, Marcelo L.; Armesto, Roberto Rodríguez; Rosmini, Marcelo R.

    2012-01-01

    The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 109 CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 1010 CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection. PMID:23000583

  4. Impact of an arbuscular mycorrhizal fungus versus a mixed microbial inoculum on the transcriptome reprogramming of grapevine roots.

    Science.gov (United States)

    Balestrini, Raffaella; Salvioli, Alessandra; Dal Molin, Alessandra; Novero, Mara; Gabelli, Giovanni; Paparelli, Eleonora; Marroni, Fabio; Bonfante, Paola

    2017-07-01

    Grapevine, cultivated for both fruit and beverage production, represents one of the most economically important fruit crops worldwide. With the aim of better understanding how grape roots respond to beneficial microbes, a transcriptome sequencing experiment has been performed to evaluate the impact of a single arbuscular mycorrhizal (AM) fungal species (Funneliformis mosseae) versus a mixed inoculum containing a bacterial and fungal consortium, including different AM species, on Richter 110 rootstock. Results showed that the impact of a single AM fungus and of a complex microbial inoculum on the grapevine transcriptome differed. After 3 months, roots exclusively were colonized after the F. mosseae treatment and several AM marker genes were found to be upregulated. The mixed inoculum led only to traces of colonization by AM fungi, but elicited an important transcriptional regulation. Additionally, the expression of genes belonging to categories such as nutrient transport, transcription factors, and cell wall-related genes was significantly altered in both treatments, but the exact genes affected differed in the two conditions. These findings advance our understanding about the impact of soil beneficial microbes on the root system of a woody plant, also offering the basis for novel approaches in grapevine cultivation.

  5. Content of sugar, organic acids and ethanol in fermented milk beverages obtained with different types of kombucha inoculum

    Directory of Open Access Journals (Sweden)

    Iličić Mirela D.

    2017-01-01

    Full Text Available The aim of this study was to examine the influence of different types and concentration of kombucha inoculum on content of sugar, organic acids and ethanol in the fermented beverages produced from milk of 0.9% fat content. Three different kombucha inoculums, cultivated on black tea with addition of sucrose: standard inoculum - 10% (w/w and 15% (w/w, concentrated by microfiltration- 10% (w/w and 15% (w/w, and concentrated by evaporation - 1.5% (w/w and 3.0% (w/w, were applied in the manufacture of fermented milk. Contents of lactose, galactose, glucose, fructose, organic acids, and ethanol in the kombuha fermented milk beverages were determined by the enzyme tests. It was found that the lactose content varied from 3.30 to 4.0 g/100g. All samples showed higher content glucose than fructose. The content of L-lactic acid in the samples ranged from 0.4 to 0.7 g/100g, while significantly lower level of D-lactic and acetic acid were determined in all samples of kombucha fermented milk (<0.06g/100g.[Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 46009

  6. Addition of Bacillus sp. inoculums in bedding for swine on a pilot scale: effect on microbial population and bedding temperature.

    Science.gov (United States)

    Corrêa, E K; Ulguim, R R; Corrêa, L B; Castilhos, D D; Bianchi, I; Gil-Turnes, C; Lucia, T

    2012-10-01

    Thermal and microbiological characteristics of beddings for swine were compared according to their depth and of addition of inoculums. Bedding was added to boxes at 0.25 (25D) and 0.50 m (50D), with three treatments: control (no inoculums); T1, with 250 g of Bacillus cereus var. toyoii at 8.4 × 10(7) CFU; and T2, with 250 g of a pool of B. subtilis, Bacillus licheniformis and Bacillus polymyxa at 8.4 × 10(7) CFU (250 g for 25D and 500 g for 50D). Mean temperatures were 28.5 ± 3.9 at the surface and 35.2 ± 8.9 inside the beddings. The most probable number (MPN) of thermophilic bacteria was higher for T1 and T2 than for the control (P<0.05). The MPN of thermophilic bacteria and fungi was greater for D50 than for D25 (P<0.05). The use of 25D without inoculums is recommended due to the reduction of thermophilic microbiota. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Consortium inoculum of five thermo-tolerant phosphate solubilizing Actinomycetes for multipurpose biofertilizer preparation.

    Science.gov (United States)

    Nandimath, Arusha P; Karad, Dilip D; Gupta, Shantikumar G; Kharat, Arun S

    2017-10-01

    Alkaline pH of the soil facilitates the conversion of phosphate present in phosphate fertilizer applied in the field to insoluble phosphate which is not available to plants. Problem of soluble phosphate deficiency arises, primarily due to needless use of phosphate fertilizer. We sought to biofertilizer with the thermo-tolerant phosphate solubilizing actinomycetes consortium that could convert insoluble phosphate to soluble phosphate at wider temperature range. In the present investigation consortium of five thermo-tolerant phosphate solubilizing actinomycetes was applied for preparation of inoculum to produce multipurpose bio-fertilizer. Phosphates solubilizing thermo-tolerant 32 actinomycetes strains were processed for identification with the use of PIBWIN software and were screened for phosphate solubilizing activity. Amongst these five actinomycetes were selected on the basis of their ability to produce cellulase, chitinase, pectinase, protease, lipase, amylase and phosphate solubilizing enzymes. Ability to produce these enzymes at 28°C and 50°C were examined. Biofertilizer was prepared by using agricultural waste as a raw material. While preparation of bio-fertilizer the pH decreased from 7.5 to 4.3 and temperature increased up to 74°C maximum at the end of 4 th week and in subsequent week it started to decline gradually till it reached around 50°C, which was found to be stable up to eighth week. This thermo-tolerant actinomycetes consortium released soluble phosphate of up to 46.7 μg ml -1 . As the mesophilic organisms die out at high temperature of composting hence thormo-tolerant actinomycetes would be the better substitute for preparation of phosphate solubilizing bio-fertilizer with added potential to degrade complex macromolecules in composting.

  8. Comparison of methods for glycogen analysis of in vitro fermentation pellets produced with strained ruminal inoculum.

    Science.gov (United States)

    Hall, Mary Beth; Hatfield, Ronald D

    2015-11-01

    Microbial glycogen measurement is used to account for fates of carbohydrate substrates. It is commonly applied to washed cells or pure cultures which can be accurately subsampled, allowing the use of smaller sample sizes. However, the nonhomogeneous fermentation pellets produced with strained rumen inoculum cannot be accurately subsampled, requiring analysis of the entire pellet. In this study, two microbial glycogen methods were compared for analysis of such fermentation pellets: boiling samples for 3h in 30% KOH (KOH) or for 15min in 0.2M NaOH (NaOH), followed by enzymatic hydrolysis with α-amylase and amyloglucosidase, and detection of released glucose. Total α-glucan was calculated as glucose×0.9. KOH and NaOH did not differ in the α-glucan detected in fermentation pellets (29.9 and 29.6mg, respectively; P=0.61). Recovery of different control α-glucans was also tested using KOH, NaOH, and a method employing 45min of bead beating (BB). For purified beef liver glycogen (water-soluble) recovery, BB (95.0%)>KOH (91.4%)>NaOH (87.4%; PBB (93.8%)>KOH (91.0%; Pglycogen (water-insoluble granules) did not differ among KOH (87.0%), NaOH (87.6%), and BB (86.0%; P=0.81), but recoveries for all were below 90%. Differences among substrates in the need for gelatinization and susceptibility to destruction by alkali likely affected the results. In conclusion, KOH and NaOH glycogen methods provided comparable determinations of fermentation pellet α-glucan. The tests on purified α-glucans indicated that assessment of recovery in glycogen methods can differ by the control α-glucan selected. Published by Elsevier B.V.

  9. Impact of preharvest and postharvest alginate treatments enriched with vanillin on postharvest decay, biochemical properties, quality and sensory attributes of table grapes.

    Science.gov (United States)

    Konuk Takma, Dilara; Korel, Figen

    2017-04-15

    Alginate solution enriched with vanillin as a bioactive compound was investigated for improving preharvest and postharvest quality and safety of table grapes. Alginate treatments with or without vanillin as preharvest spray and postharvest coating were implemented on table grapes of Alphonse Lavalleé and Razaki cultivars. Fungal decay, biochemical properties, quality and sensory attributes were evaluated at day of preharvest treatment, at harvesting and during 35days of storage at 4±2°C. Alginate treatments with or without vanillin were effective in preventing weight and firmness losses. Total soluble solids, titratable acidity, and color of grapes coated with alginate coatings with or without vanillin showed minor changes compared to control grapes. Alginate coating incorporating vanillin provided significant reduction (1.73log CFU/g) in yeast-mold growth. Moreover, the coatings maintained greater total phenolic content and antioxidant activity compared to others during postharvest storage. In terms of sensory attributes, appearance was ranked as the highest for alginate coating without vanillin due to glossiness of alginate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Fungicidal activity of essential oils of Cinnamomum zeylanicum (L.) and Syzygium aromaticum (L.) Merr et L.M. Perry against crown rot and anthracnose pathogens isolated from banana.

    Science.gov (United States)

    Ranasinghe, L; Jayawardena, B; Abeywickrama, K

    2002-01-01

    To develop a post-harvest treatment system against post-harvest fungal pathogens of banana using natural products. Colletotrichum musae was isolated and identified as the causative agent responsible for anthracnose peel blemishes while three fungi, namely Lasiodiplodia theobromae, C. musae and Fusarium proliferatum, were identified as causative agents responsible for crown rot. During the liquid bioassay, cinnamon [Cinnamomum zeylanicum (L.)] leaf, bark and clove [Syzygium aromaticum (L.)] oils were tested against the anthracnose and crown rot pathogens. The test oils were fungistatic and fungicidal against the test pathogens within a range of 0.03-0.11% (v/v). Cinnamon and clove essential oils could be used as antifungal agents to manage post harvest fungal diseases of banana. Cinnamon and clove essential oil could be used as alternative post-harvest treatments on banana. Banana treated with essential oil is chemically safe and acceptable to consumers. Benomyl (Benlate), which is currently used to manage fungal pathogens, can cause adverse health effects and could be replaced with volatile essential oils.

  11. Public health implications of post-harvest fish handling practices in ...

    African Journals Online (AJOL)

    A wide range of handling practices for harvested fish exists and they have economic as well as public health implications. This paper is a review of the existing problems in fish handling technologies at post-harvest in Nigeria. The public health aspects with the associated implications are highlighted. Status of policy on fish ...

  12. Molecular analysis of differentially expressed genes during postharvest deterioration in cassava (Manihot esculenta Crantz) tuberous roots

    NARCIS (Netherlands)

    Huang, J.; Bachem, C.W.B.; Jacobsen, E.; Visser, R.

    2001-01-01

    One of the major problems for cassava is the rapid deterioration after harvesting cassava tuberous roots, which limits the possibilities for production and distribution of cassava in the world. Postharvest deterioration is an inherent problem for cassava since wounding and mechanical damage of the

  13. Combined preharvest and postharvest treatments affect rapid leaf wilting in Bouvardia cut flowers

    NARCIS (Netherlands)

    Schouten, Rob E.; Dien, van Luka; Shahin, Arwa; Heimovaara, Sjoukje; Meeteren, van Uulke; Verdonk, Julian C.

    2018-01-01

    Bouvardia is an ornamental shrub, commercially cultivated as flowering stem. Occasionally, negative water balance, which leads to rapid leaf wilting, ends vase life immediately. This work studies the effect of preharvest and postharvest conditions on vase life, water uptake and transpiration.

  14. Reducing Postharvest Losses during Storage of Grain Crops to Strengthen Food Security in Developing Countries

    Directory of Open Access Journals (Sweden)

    Deepak Kumar

    2017-01-01

    Full Text Available While fulfilling the food demand of an increasing population remains a major global concern, more than one-third of food is lost or wasted in postharvest operations. Reducing the postharvest losses, especially in developing countries, could be a sustainable solution to increase food availability, reduce pressure on natural resources, eliminate hunger and improve farmers’ livelihoods. Cereal grains are the basis of staple food in most of the developing nations, and account for the maximum postharvest losses on a calorific basis among all agricultural commodities. As much as 50%–60% cereal grains can be lost during the storage stage due only to the lack of technical inefficiency. Use of scientific storage methods can reduce these losses to as low as 1%–2%. This paper provides a comprehensive literature review of the grain postharvest losses in developing countries, the status and causes of storage losses and discusses the technological interventions to reduce these losses. The basics of hermetic storage, various technology options, and their effectiveness on several crops in different localities are discussed in detail.

  15. Post-harvest technologies for various crops of pakistan: status quo, employment generation and prospects

    International Nuclear Information System (INIS)

    Ahmad, M.

    2005-01-01

    The climatic conditions of Pakistan vary from tropical to temperate, allow 40 different kinds of vegetables, 21 type of fruit, and 5 major crops (wheat, cotton, rice, sugarcane, and maize) to grow. During the peak harvest-season, a great proportion of fresh agricultural/horticultural produce is lost, due to unavailability of suitable post-harvest technologies. An effort was made to present the status quo, constraints, Government policies and possible post-harvest technologies that can be developed/adopted in the country to generate employment in the rural areas. Secondary processing-industry (flour mills, sugar mills, oil mills etc.) is fairly developed in the country. However. primary processing of agricultural produce is poorly developed in the country. The higher cost of the processed products, consumers habits of eating fresh commodities, seasonability of fresh fruit and vegetables, and low quality of the processed products are the key-constraints for the slow growth of post-harvest processing industry. By removing these constraints, and by developing/adopting various technologies, identified in this paper, we may help to establish post-harvest processing industry on sound footings. Consequently, the employment-opportunities will increase in the rural areas of the country. (author)

  16. Application of biofilms in the post-harvest conservation of pequi ...

    African Journals Online (AJOL)

    The aim of this study was to assess the post-harvest conservation of this fruit by using different sources of biofilms as a means to ensure the maintenance of fruit physical and chemical characteristics in order to increase its shelf life. Fruits were submitted to four treatments: control (no coating) (T1); 0.5% w/w carnauba wax ...

  17. Physically based modelling and optimal operation for product drying during post-harvest processing.

    NARCIS (Netherlands)

    Boxtel, van A.J.B.; Lukasse, L.; Farkas, I.; Rendik, Z.

    1996-01-01

    The development of new procedures for crop production and post-harvest processing requires models. Models based on physical backgrounds are most useful for this purpose because of their extrapolation potential. An optimal procedure is developed for alfalfa drying using a physical model. The model

  18. Sensitivity of the quarantine pest rough sweetpotato weevil, Blosyrus asellus to postharvest irradiation treatment

    Science.gov (United States)

    Rough sweetpotato weevil, Blosyrus asellus (Olivier), is a new quarantine pest of Hawaii sweetpotatoes. Currently, sweetpotatoes can be exported from Hawaii to the U.S. mainland using a postharvest irradiation treatment of 150 Gy to control three other regulated insect pests. Studies were conducted...

  19. EFFECT OF CONVENTIONAL AND ALTERNATIVE PRODUCTS ON POSTHARVEST DISEASE CONTROL IN AVOCADOS

    Directory of Open Access Journals (Sweden)

    Ivan Herman Fischer

    2018-02-01

    Full Text Available ABSTRACT Postharvest diseases constitute a serious problem for avocado commercialization. Thus, the present study aimed to evaluate the effect of conventional and alternative products in controlling diseases affecting ‘Hass’ avocados in the field and in the postharvest by carrying out physicochemical characterization of fruits subjected to postharvest treatments. In the field, besides the management adopted by the farmer, seven products were sprayed three times during fruiting for evaluation. Postharvest products were diluted in water or in oxidized polyethylene wax and shellac. Water treatments with potassium phosphite, Soil-Set®, chlorine dioxide, thyme essential oil, sodium bicarbonate, lemon grass essential oil and thiabendazole reduced the incidence of diseased fruits, and anthracnose, the main disease, was controlled with sodium bicarbonate, lemon grass essential oil and thiabendazole. Greater soluble solids content was found for control (water, chlorine dioxide, acibenzolar-S-methyl and thiabendazole. For the products that reduced anthracnose, there was no correlation between the disease and the physicochemical parameters, evidencing that the disease control is not associated with delayed ripening. For wax treatments, diseases were not controlled, and the fruits presented lower titratable acidity with thyme essential oil, sodium bicarbonate, control (wax, acibenzolar-S-methyl and lemon grass essential oil. Control and thyme essential oil were highlighted for maintaining the green coloration of the fruit skin for the shortest period. Under field conditions, azoxystrobin, thiabendazole, difenoconazole+azoxystrobin and acibenzolar-S-methyl+azoxystrobin reduced the occurrence of diseased fruits, while anthracnose control was only obtained with azoxystrobin.

  20. Reducing Postharvest Losses during Storage of Grain Crops to Strengthen Food Security in Developing Countries.

    Science.gov (United States)

    Kumar, Deepak; Kalita, Prasanta

    2017-01-15

    While fulfilling the food demand of an increasing population remains a major global concern, more than one-third of food is lost or wasted in postharvest operations. Reducing the postharvest losses, especially in developing countries, could be a sustainable solution to increase food availability, reduce pressure on natural resources, eliminate hunger and improve farmers' livelihoods. Cereal grains are the basis of staple food in most of the developing nations, and account for the maximum postharvest losses on a calorific basis among all agricultural commodities. As much as 50%-60% cereal grains can be lost during the storage stage due only to the lack of technical inefficiency. Use of scientific storage methods can reduce these losses to as low as 1%-2%. This paper provides a comprehensive literature review of the grain postharvest losses in developing countries, the status and causes of storage losses and discusses the technological interventions to reduce these losses. The basics of hermetic storage, various technology options, and their effectiveness on several crops in different localities are discussed in detail.

  1. Postharvest flower development in asiatic hybrid lilies as related to tepal carbohydrate status

    NARCIS (Netherlands)

    Meulen-Muisers, van der J.J.M.; Oeveren, van J.C.; Plas, van der L.H.W.; Tuyl, van J.M.

    2001-01-01

    For three Asiatic hybrid lily cultivars (‘Bright Beauty’, ‘Fashion’, ‘Orlito’) the potential postharvest performance of floral buds in terms of growth, anthesis and longevity was studied in relation to tepal carbohydrate status. To determine the importance of carbohydrate redistribution within lily

  2. Genetic and physiological aspects of postharvest flower longevity in Asiatic hybrid lilies (Lilium L.)

    NARCIS (Netherlands)

    Meulen-Muisers, van der J.J.M.

    2000-01-01

    In The Netherlands Lilium is economically the fourth overall flower crop for cut flower production. Longevity is a main quality characteristic for cut flowers. During postharvest handling of Asiatic hybrid lilies pretreatment with chemical solutions containing silver is

  3. Identification of determinants of postharvest losses in Zimbabwean tomato supply chains as basis for dedicated interventions

    NARCIS (Netherlands)

    Macheka, L.; Spelt, E.J.H.; Bakker, E.J.; Vorst, van der J.G.A.J.; Luning, P.A.

    2018-01-01

    Postharvest losses (PHL) are a major problem in tomato supply chains, especially in tropical climates, as up to 40% of harvested fruits are estimated to decay along the chain. The study aimed at identifying which farmers' context characteristics, logistics and quality control activities relate with

  4. Quantifying residues from postharvest fumigation of almonds and walnuts with propylene oxide

    Science.gov (United States)

    A novel analytical approach, involving solvent extraction with methyl tert-butyl ether (MTBE) followed by gas chromatography (GC), was developed to quantify residues that result from the postharvest fumigation of almonds and walnuts with propylene oxide (PPO). Verification and quantification of PPO,...

  5. Effect of visible light treatments on postharvest senescence of broccoli (Brassica oleracea L.).

    Science.gov (United States)

    Büchert, Agustin M; Gómez Lobato, Maria E; Villarreal, Natalia M; Civello, Pedro M; Martínez, Gustavo A

    2011-01-30

    Broccoli (Brassica oleracea L.) is a rapidly perishable vegetable crop. Several postharvest treatments have been applied in order to delay de-greening. Since light has been shown to have an effect on pigment accumulation during development and darkness is known to induce senescence, the effect of continuous and periodic exposure to low-intensity white light at 22 °C on postharvest senescence of broccoli heads was assayed. Exposure to a constant dose of 12 micromol m(-2) s(-1) was selected as the most suitable treatment and was employed for subsequent experiments. During the course of the treatments, hue and L* values as well as chlorophyll content and visual observation of florets indicated an evident delay in yellowing in treated samples compared with controls. No statistically significant differences in total protein content were found, but soluble protein content was higher in treated samples. Total and reducing sugar as well as starch levels decreased during postharvest senescence, with lower values in control samples. The results of this study indicate that storage under continuous low-intensity light is an efficient and low-cost treatment that delays postharvest senescence while maintaining the quality of harvested broccoli florets. 2010 Society of Chemical Industry.

  6. Impact of postharvest ripening strategies on 'Hass' avocado fatty acid profiles

    NARCIS (Netherlands)

    Pedreschi Plasencia, Romina; Hollak, S.; Harkema, H.; Otma, E.; Robledo, P.; Westra, Eelke; Berg-Somhorst, van de Dianne; Ferreyra, R.; Defilippi, B.G.

    2016-01-01

    Persea americana Mill. cv 'Hass' is a subtropical fruit highly appreciated as a rich source of fatty acids mostly of the monounsaturated type. Commonly commercially applied postharvest ripening strategies for the ready to eat market based on high temperature (15 and 20 °C) and external ethylene

  7. Commodity Systems Assessment Methodology of Postharvest Losses in Vegetable Amaranths: The Case of Tamale, Ghana

    Directory of Open Access Journals (Sweden)

    Mildred Osei-Kwarteng

    2017-01-01

    Full Text Available A semistructured questionnaire based on the commodity system assessment methodology (CSAM was used to determine postharvest losses in vegetable amaranths (VA. Fifty producers and retailers were randomly selected from five and four major VA producing areas and markets, respectively, and interviewed. Data obtained were subjected to descriptive statistical analyses. The survey revealed that absence of laws, regulation, incentives, and inadequate technical information affected the production of VA. The utmost preproduction challenge was poor quality seeds with poor seed yield (35%, low viability (19%, and nontrueness (46%. It was noted that some cultural practices including planting pattern and density, irrigation, and fertiliser use had effects on postharvest losses. Some postharvest practices used were cleaning with water, trimming, sorting, and grading. Usually the produce was transported to marketing centers by cars and motor cycle trailers. Generally poor temperature management after harvest was a big challenge for the postharvest handling of VA. The potential of vegetable amaranths as a commodity in the study area can be enhanced by providing the necessary institutional support, incentives, and use of good management practices along the value chain. An interdisciplinary approach and quantification of losses along the chain are recommended for any future study.

  8. Pre-harvest methyl jasmonate treatment enhances cauliflower chemoprotective attributes without a loss in postharvest quality.

    Science.gov (United States)

    Ku, Kang Mo; Choi, Jeong-Hee; Kushad, Mosbah M; Jeffery, Elizabeth H; Juvik, John A

    2013-06-01

    Methyl jasmonate (MeJA) treatment can significantly increase glucosinolate (GS) concentrations in Brassica vegetables and potentially enhance anticancer bioactivity. Although MeJA treatment may promote ethylene biosynthesis, which can be detrimental to postharvest quality, there are no previous reports of its effect on cauliflower postharvest quality. To address this, cauliflower curds in field plots were sprayed with either 0.1 % Triton X-100 (control) or 500 μM MeJA solutions four days prior to harvest, then stored at 4 °C. Tissue subsamples were collected after 0, 10, 20, and 30 days of postharvest storage and assayed for visual color change, ethylene production, GS concentrations, and extract quinone reductase inductive activity. MeJA treatment increased curd GS concentrations of glucoraphanin, glucobrassicin, and neoglucobrassicin by 1.5, 2.4, and 4.6-fold over controls, respectively. MeJA treated cauliflower showed significantly higher quinone reductase activity, a biomarker for anticancer bioactivity, without reducing visual color and postharvest quality for 10 days at 4 °C storage.

  9. Postharvest fumigation of California table grapes with ozone to control Western black widow spider (Araneae: Theridiidae)

    Science.gov (United States)

    Ozone fumigations were evaluated for postharvest control of Western black widow spider (BWS), Latrodectus hesperus (Chamberlin and Ivie), in fresh table grapes destined for export from California USA. Mature adult female black widow spiders were contained in separate gas-permeable cages within a flo...

  10. Resistance to post-harvest microbial rot in yam: Integration of ...

    African Journals Online (AJOL)

    Post-harvest microbial rot is an important disease that causes severe losses in yam (Dioscorea spp.) storage. Rot from microbial infection of healthy yam tubers reduces their table quality and renders them unappealing to consumers. A study was carried out at Bimbilla in the Nanumba North District of Ghana to evaluate ...

  11. isolation and identification of postharvest spoilage fungi associated

    African Journals Online (AJOL)

    DR. AMINU

    (5%). Proper handling from the farm as well as during storage and the avoidance of mixing of diseased ones with the healthy ones were identified as important factors in preventing loss. The use of suitable chemical treatment of the orange is also recommended as means of reducing economic loss due to fungal pathogens.

  12. Emerging Pathogens Initiative (EPI)

    Data.gov (United States)

    Department of Veterans Affairs — The Emerging Pathogens Initiative (EPI) database contains emerging pathogens information from the local Veterans Affairs Medical Centers (VAMCs). The EPI software...

  13. Recent Advances in Physical Post-Harvest Treatments for Shelf-Life Extension of Cereal Crops

    Science.gov (United States)

    Schmidt, Marcus; Zannini, Emanuele; Arendt, Elke K.

    2018-01-01

    As a result of the rapidly growing global population and limited agricultural area, sufficient supply of cereals for food and animal feed has become increasingly challenging. Consequently, it is essential to reduce pre- and post-harvest crop losses. Extensive research, featuring several physical treatments, has been conducted to improve cereal post-harvest preservation, leading to increased food safety and sustainability. Various pests can lead to post-harvest losses and grain quality deterioration. Microbial spoilage due to filamentous fungi and bacteria is one of the main reasons for post-harvest crop losses and mycotoxins can induce additional consumer health hazards. In particular, physical treatments have gained popularity making chemical additives unnecessary. Therefore, this review focuses on recent advances in physical treatments with potential applications for microbial post-harvest decontamination of cereals. The treatments discussed in this article were evaluated for their ability to inhibit spoilage microorganisms and degrade mycotoxins without compromising the grain quality. All treatments evaluated in this review have the potential to inhibit grain spoilage microorganisms. However, each method has some drawbacks, making industrial application difficult. Even under optimal processing conditions, it is unlikely that cereals can be decontaminated of all naturally occurring spoilage organisms with a single treatment. Therefore, future research should aim for the development of a combination of treatments to harness their synergistic properties and avoid grain quality deterioration. For the degradation of mycotoxins the same conclusion can be drawn. In addition, future research must investigate the fate of degraded toxins, to assess the toxicity of their respective degradation products. PMID:29565832

  14. Ecosystem screening approach for pathogen-associated microorganisms affecting host disease.

    Science.gov (United States)

    Galiana, Eric; Marais, Antoine; Mura, Catherine; Industri, Benoît; Arbiol, Gilles; Ponchet, Michel

    2011-09-01

    The microbial community in which a pathogen evolves is fundamental to disease outcome. Species interacting with a pathogen on the host surface shape the distribution, density, and genetic diversity of the inoculum, but the role of these species is rarely determined. The screening method developed here can be used to characterize pathogen-associated species affecting disease. This strategy involves three steps: (i) constitution of the microbial community, using the pathogen as a trap; (ii) community selection, using extracts from the pathogen as the sole nutrient source; and (iii) molecular identification and the screening of isolates focusing on their effects on the growth of the pathogen in vitro and host disease. This approach was applied to a soilborne plant pathogen, Phytophthora parasitica, structured in a biofilm, for screening the microbial community from the rhizosphere of Nicotiana tabacum (the host). Two of the characterized eukaryotes interfered with the oomycete cycle and may affect the host disease. A Vorticella species acted through a mutualistic interaction with P. parasitica, disseminating pathogenic material by leaving the biofilm. A Phoma species established an amensal interaction with P. parasitica, strongly suppressing disease by inhibiting P. parasitica germination. This screening method is appropriate for all nonobligate pathogens. It allows the definition of microbial species as promoters or suppressors of a disease for a given biotope. It should also help to identify important microbial relationships for ecology and evolution of pathogens.

  15. Pathogenic Streptomyces spp. abundance affected by potato cultivars.

    Science.gov (United States)

    Nahar, Kamrun; Goyer, Claudia; Zebarth, Bernie J; Burton, David L; Whitney, Sean

    2018-04-16

    Potato cultivars vary in their tolerance to common scab (CS), however how they affect CS-causing Streptomyces spp. populations over time is poorly understood. This study investigated the effects of potato cultivar on pathogenic Streptomyces spp. abundance, measured using quantitative PCR, in three spatial locations in a CS-infested field: 1) soil close to the plant (SCP); 2) rhizosphere (RS); and 3) geocaulosphere (GS) soils. Two tolerant (Gold Rush, Hindenburg) and two susceptible cultivars (Green Mountain, Agria) were tested. The abundance of pathogenic Streptomyces spp. significantly increased in late August compared with other dates in RS of susceptible cultivars in both years. Abundance of pathogenic Streptomyces spp., when averaged over locations and time, was significantly greater in susceptible cultivars compared with tolerant cultivars in 2014. Principal coordinates analysis showed that SCP and RS soil properties (pH, organic carbon and nitrogen concentrations) explained 68% and 76% of total variation in Streptomyces spp. abundance among cultivars in 2013, respectively, suggesting that cultivars influenced CS pathogen growth conditions. The results suggested that the genetic background of potato cultivars influenced the abundance of pathogenic Streptomyces spp., with 5 to 6 times more abundant Streptomyces spp. in RS of susceptible cultivars compared with tolerant cultivars, which would result in substantially more inoculum left in the field after harvest.  .

  16. Fungi of the genus Fusarium as pathogens of soybean seedlings

    Directory of Open Access Journals (Sweden)

    Joanna Marcinkowska

    2013-12-01

    Full Text Available Twenty isolates of fungi of the genus Fusarium collected in the period 1980-1982 from various organs of diseased soybean plants were investigated. Eight of them proved pathogenic to soybean seedlings. The species F. culmorum was most numerously represented among the isolated (4 of 8 pathogens. Isolates of F. sambucinum were also pathogenic (2 of 4 and those of F. soloni (1 of 3, too. The only isolate of F. avenaceum also caused seedling blight. Two isolates of F. oxysporum and two of F. arthrosporioides were not pathogenic. Numerous isolates affected seed gernination and one greatly inhibited growth of the infected seedlings. Pathogenicity was tested in the laboratory in Petri plates on isolate cultures and on filter paper imbibed with fungal inoculum and, in the greenhouse on a peat and perlite substrate. The degree of infection and the character of the disease symptoms depended on the experimental conditions. The results of experiments in plates and in the greenhouse supplemented one another.

  17. Post-storage cell wall metabolism in two sweet cherry (Prunus avium L.) cultivars displaying different postharvest performance

    OpenAIRE

    Belge, Burcu; Comabella, Eva; Graell i Sarle, Jordi; Lara Ayala, Isabel

    2015-01-01

    The biochemical processes underlying firmness loss of sweet cherry (Prunus avium L.) fruit are poorly understood.Studies on cell wall metabolism of sweet cherry have been generally undertaken during on-tree development or at harvest maturity, while published reports on postharvest changes are scarce and fragmentary. In this work, cell wall modifications after storage at 0 ºC were studied in two cherry cultivars ('Celeste' and 'Somerset') displaying different postharvest potential. Firmness wa...

  18. Assessment of the efficiency of essential oils in the preservation of postharvest papaya in an antimicrobial packaging system

    OpenAIRE

    Espitia,Paula Judith Perez; Soares,Nilda de Fátima Ferreira; Botti,Laura Costa Moreira; Melo,Nathália Ramos de; Pereira,Olinto Liparini; Silva,Washington Azevêdo da

    2012-01-01

    Rot and damage caused by post-harvest phytopathogenic fungi affect fruit quality. Essential oils (EO) are considered as an alternative to fungicides. Postharvest diseases of fruits may also be controlled by the bagging approach and the use of antimicrobial packaging. Based on the beneficial properties of EO and the concepts of bagging and antimicrobial packaging, this study aimed to develop sachets containing EO to be used as part of an antimicrobial packaging system. The activities of oregan...

  19. Fermentation of Ammonia Fiber Expansion Treated and Untreated Barley Straw in a Rumen Simulation Technique Using Rumen Inoculum from Cattle with Slow versus Fast Rate of Fiber Disappearance.

    Science.gov (United States)

    Griffith, Candace L; Ribeiro, Gabriel O; Oba, Masahito; McAllister, Tim A; Beauchemin, Karen A

    2016-01-01

    The purpose of this study was to determine the effect of rumen inoculum from heifers with fast vs. slow rate of in situ fiber digestion on the fermentation of complex versus easily digested fiber sources in the forms of untreated and Ammonia Fiber Expansion (AFEX) treated barley straw, respectively, using an artificial rumen simulation technique (Rusitec). In situ fiber digestion was measured in a previous study by incubating untreated barley straw in the rumen of 16 heifers fed a diet consisting of 700 g/kg barley straw and 300 g/kg concentrate. The two heifers with fastest rate of digestion (Fast ≥ 4.18% h -1 ) and the two heifers with the slowest rate of digestion (Slow ≤ 3.17% h -1 ) were chosen as inoculum donors for this study. Two Rusitec apparatuses each equipped with eight fermenters were used in a completely randomized block design with two blocks (apparatus) and four treatments in a 2 × 2 factorial arrangement of treatments (Fast or Slow rumen inoculum and untreated or AFEX treated straw). Fast rumen inoculum and AFEX straw both increased ( P 0.05) methane production per gram of digested material for both untreated and AFEX straw, and reduced (interaction, P < 0.05) acetate: propionate ratio for untreated straw. Greater relative populations of Ruminococcus albus ( P < 0.05) and increased microbial N production ( P = 0.045) were observed in Fast rumen inoculum. AFEX straw in Fast inoculum had greater total bacterial populations than Slow, but for untreated straw this result was reversed (interaction, P = 0.013). These findings indicate that differences in microbial populations in rumen fluid contribute to differences in the capacity of rumen inoculum to digest fiber.

  20. Soil amendments improve microbial ecology parameters of "topsoil inoculum" used in post-mining restoration

    Science.gov (United States)

    Kumaresan, Deepak; Munoz-Rojas, Miriam; Moreira-Grez, Benjamin; Kariman, Khalil; Whiteley, Andrew

    2017-04-01

    Mine operations generate substantial volumes of waste substrates, which are crushed and/or chemically treated waste rock from which ores are extracted. Establishment of rehabilitated landforms using post-mining substrates (i.e. waste rocks, tailings) that typically exhibit extreme conditions (such as high pH, nutrient deficiency, excessive salinity and metal toxicity) can be a major environmental problem and a critical issue during mine closure operations. More importantly, mine sites are located predominantly in arid or semi-arid lands where our understanding of basic ecosystem processes and microbial interactions with native plants (e.g. Eucalyptus spp., Acacia spp., Grevillea spp. in Western Australia) are limited. Despite the wide acknowledgement on the impact of microbial functional diversity on overall soil and plant health, no detailed attention has been paid to understand the role of belowground microbial functional diversity in the context of mine rehabilitation strategies. In this research, we investigated the role of nitrogen-based and microbial consortia amendments on improving the microbial ecology parameters of "topsoil inoculum" and subsequently its cascading effect on seedling establishment and plant morphology of Acacia ancistrocarpa, a legume native to the Pilbara and other regions of Western Australia and commonly used in arid zone restoration. The study was conducted under controlled environmental conditions in potted plants using topsoil retrieved from previously stockpiled material as growth media. A morphological assessment was undertaken to measure shoot length, shoot weight, root length, root area and root weight. Soil chemical properties, e.g. carbon, nitrogen and trace metals concentrations were determined Microbial activity was measured with the 1-day CO2 test, which determines soil microbial respiration rate based on the measurement of the CO2 burst produced after moistening dry soil (Muñoz-Rojas et al., 2016). Bacterial and archaeal

  1. High salinity relay as a post-harvest processing method for reducing Vibrio vulnificus levels in oysters (Crassostrea virginica).

    Science.gov (United States)

    Audemard, Corinne; Kator, Howard I; Reece, Kimberly S

    2018-08-20

    High salinity relay of Eastern oysters (Crassostrea virginica) was evaluated as a post-harvest processing (PHP) method for reducing Vibrio vulnificus. This approach relies on the exposure of oysters to natural high salinity waters and preserves a live product compared to previously approved PHPs. Although results of prior studies evaluating high salinity relay as a means to decrease V. vulnificus levels were promising, validation of this method as a PHP following approved guidelines is required. This study was designed to provide data for validation of this method following Food and Drug Administration (FDA) PHP validation guidelines. During each of 3 relay experiments, oysters cultured from 3 different Chesapeake Bay sites of contrasting salinities (10-21 psu) were relayed without acclimation to high salinity waters (31-33 psu) for up to 28 days. Densities of V. vulnificus and densities of total and pathogenic Vibrio parahaemolyticus (as tdh positive strains) were measured using an MPN-quantitative PCR approach. Overall, 9 lots of oysters were relayed with 6 exhibiting initial V. vulnificus >10,000/g. As recommended by the FDA PHP validation guidelines, these lots reached both the 3.52 log reduction and the levels ranged from 2 to 61% after 28 days of relay. Although the identification of the factors implicated in oyster mortality will require further examination, this study strongly supports the validation of high salinity relay as an effective PHP method to reduce levels of V. vulnificus in oysters to endpoint levels approved for human consumption. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Physiological attributes of fungi associated with stem end rot of mango (mangifera indica l.) cultivars in postharvest fruit losses

    International Nuclear Information System (INIS)

    Maqsood, A.; Nafees, M.; Ashraf, I.; Qureshi, R.

    2014-01-01

    Stem end rot majorly contribute in post-harvest losses of mango during storage. Maximum disease incidence (70%) was recorded in Sindhari cultivar followed by Chaunsa (64%), Fajri (62.5%) and 50% in both Langra and Anwar ratol. In vitro studies were carried out to identifyfungal pathogens responsible for rotting and decaying mango fruits during storage along with isolation and testing their pathogencity on healthy fruits. Results revealed that all selected commercial mango varieties infected by stem end rot. Colletotrichum gloeosporioides, Lasidodiplodia theobromae, Alternaria alternate, Aspergillus niger, Dothiorella domonicana were identified from Sindhri mango fruits, in which of C. gloeosporioides was found the most prevalent. Phomopsis mangiferae, Botryodiplodia theobromae, Altrnaria spp. Aspergillus niger, A. flavis were found in Chaunsa and Phomopsis mangiferae was most prevalent, while Botryodiplodia theobromae caused infection to locally cosumed Fajri variety. Effect of abiotic factors like pH, temperature, light intensity and carbon sources were tested against these isolates. The most efficient carbon source was glucose, which supported the maximum growth of the P. mangiferae and L. Theobromae, while C. gloeosporioides had maximum growth on lactose. All fungi had maximum growth at pH range of 6-6.5 and temperature range of 25-30 degree C on PDA medium. Alternate cycles of 12hr light and 12 hr darkness resulted maximum mycelial growth as compared to the 24 hour continuous exposure to either dark or light. Susceptibility of fungi with cultivars and intensity of spread under specific abiotic conditions provides basic information in this paper to minimize stem end rot of mango in field and storage conditions. (author)

  3. assessment of injection of liquid rhizobial inoculum and traditional inoculation of soybean under furrow and drip irrigation

    International Nuclear Information System (INIS)

    Janat, M.; Kurdali, F.

    2008-01-01

    Soybean in naturally N 2 -fixing legume, but it needs artificial inoculation with appropriate strains of rhizobia when introduced to land not previously cultivated to the crop. As soybean is being introduced to Syria, inoculation with Bradyrhizobium japonicum is essential to ensure effective biological nitrogen fixation by the crop. The question is: what is the most effective mean of inoculation?. As Syria is a water-short country, we examined the possibility of applying the rhizobial inoculant in irrigation system (Biofertigation) in contrast with the conventional seed pelleting application. In a 2 year experiment at a research station near Damascus, we compared seed pelleting of the inoculant under furrow and drip irrigation, with repeated inoculation by injection of a liquid culture rhizobial inoculum through the drip system. Drip irrigation enhanced N 2 fixation by soybean regardless of inoculation technique ad repeated inoculation. Injection of the liquid rhizobial inoculum through drip irrigation system was shown to enhances the acquisition of atmospheric N 2 and improve N 2 fixation by soybean.(author)

  4. Effectiveness of Accelerator and Inoculum in Fermentation of Goat’s Rumen Contents as Animal Feed Ingredients

    Science.gov (United States)

    Bakrie, B.; Sente, U.; Mayasari, K.; Syah, R. F.

    2018-02-01

    The goat’s rumen contents is slaughterhouse waste that has potential to be used as animal feed, but it has to be first processed into silage. This study aims to determine the type of accelerator and to investigate whether the addition of inoculum was required during the fermentation process. The research was conducted using a Completely Randomized Factorial Design, consisting of 2 treatment factors and 6 replications. The treatment factors were: a) Accelerator (rice bran or cassava pomade/onggok); b) Inoculum Lactobacillus plantarum (with or without using inoculant). Results showed that there was an increase in crude protein (CP) content with the use of rice bran at after fermentation compared to before fermentation. The CP contents with the use of onggok almost the same at after and before fermentation. Increase in the content of crude fiber (CF) after fermentation was both for using rice bran or onggok. However, the content of CF using onggok was much higher than with rice bran. There was no significant effect for both types of accelerators used in CP and CF contents at after fermentation with or without the addition of Lactobacillus plantarum as the inoculant. It can be concluded that for the fermentation of goat’s rumen contents it is better to use rice bran rather than onggok as the accelerator and inoculant is not required during the fermentationprocess.

  5. Enhancement of acidogenic fermentation for volatile fatty acid production from food waste: Effect of redox potential and inoculum.

    Science.gov (United States)

    Yin, Jun; Yu, Xiaoqin; Zhang, Yeer; Shen, Dongsheng; Wang, Meizhen; Long, Yuyang; Chen, Ting

    2016-09-01

    The aim of this study was to explore the effects of redox potential (ORP) and inoculum on volatile fatty acids (VFAs) production from food waste by acidogenic fermentation. Four experimental conditions with two ORP levels were tested: limited aeration conditions with ORP level of -100 to -200mV inoculating anaerobic sludge (LA+AnS) or aerobic sludge (LA+AeS), and anaerobic conditions with ORP level of -200 to -300mV inoculating anaerobic sludge with 2-bromoethanosulfophate (AN+BES) and without BES (AN). The maximal VFA yield (0.79g COD/g VS) was attained in LA+AnS reactor due to enhanced hydrolysis of substrates, especially proteins (degradation efficiency 78.3%). A higher frequency of phylum Firmicutes under limited aeration conditions (42.2-48.2%) was observed than that under anaerobic conditions (21.1%). The microbial community was more diverse in LA+AnS reactors than LA+AeS. We conclude that appropriate ORP level (from -100 to -200mV) and inoculum play essential roles in VFA production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Effects of inoculum type and bulk dissolved oxygen concentration on achieving partial nitrification by entrapped-cell-based reactors.

    Science.gov (United States)

    Rongsayamanont, Chaiwat; Limpiyakorn, Tawan; Khan, Eakalak

    2014-07-01

    An entrapment of nitrifiers into gel matrix is employed as a tool to fulfill partial nitrification under non-limiting dissolved oxygen (DO) concentrations in bulk solutions. This study aims to clarify which of these two attributes, inoculum type and DO concentration in bulk solutions, is the decisive factor for partial nitrification in an entrapped-cell based system. Four polyvinyl alcohol entrapped inocula were prepared to have different proportions of nitrite-oxidizing bacteria (NOB) and nitrite-oxidizing activity. At a DO concentration of 3 mg l(-1), the number of active NOB cells in an inoculum was the decisive factor for partial nitrification enhancement. However, when the DO concentration was reduced to 2 mg l(-1), all entrapped cell inocula showed similar degrees of partial nitrification. The results suggested that with the lower bulk DO concentration, the preparation of entrapped cell inocula is not useful as the DO level becomes the decisive factor for achieving partial nitrification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Chemical characteristics of beddings for swine: effects of bedding depths and of addition of inoculums in a pilot-scale.

    Science.gov (United States)

    Corrêa, E K; Corezzolla, J L; Corrêa, M N; Bianchi, I; Gil-Turnes, C; Lucia, T

    2012-11-01

    The effect of depths and of addition of inoculums on the chemical content of swine beddings was evaluated. For beddings 0.25m (25D) and 0.50m (50D) deep, three treatments were tested in two repeats with the same beddings: control (no inoculums); T1 (250g of Bacillus cereus var. toyoii at 8.4×10(7)CFU/g); and T2 (250g of a pool of Bacillus sp. at 8.4×10(7)CFU/g) (250g for 25D and 500g for 50D). For 25D, the C:N ratio was lower, but N, K and C contents were greater than for 50D (P0.05). In the second repeat, beddings presented lower C:N ratio and greater N, P and K contents than in the first repeat (P<0.05). Thus, the compost produced after using 25D twice had greater fertilizer value than that of 50D. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Oxidative Stress Associated with Chilling Injury in Immature Fruit: Postharvest Technological and Biotechnological Solutions.

    Science.gov (United States)

    Valenzuela, Juan Luis; Manzano, Susana; Palma, Francisco; Carvajal, Fátima; Garrido, Dolores; Jamilena, Manuel

    2017-07-08

    Immature, vegetable-like fruits are produced by crops of great economic importance, including cucumbers, zucchini, eggplants and bell peppers, among others. Because of their high respiration rates, associated with high rates of dehydration and metabolism, and their susceptibility to chilling injury (CI), vegetable fruits are highly perishable commodities, requiring particular storage conditions to avoid postharvest losses. This review focuses on the oxidative stress that affects the postharvest quality of vegetable fruits under chilling storage. We define the physiological and biochemical factors that are associated with the oxidative stress and the development of CI symptoms in these commodities, and discuss the different physical, chemical and biotechnological approaches that have been proposed to reduce oxidative stress while enhancing the chilling tolerance of vegetable fruits.

  9. Significance of Genetic, Environmental, and Pre- and Postharvest Factors Affecting Carotenoid Contents in Crops: A Review.

    Science.gov (United States)

    Saini, Ramesh Kumar; Keum, Young-Soo

    2018-05-30

    Carotenoids are a diverse group of tetraterpenoid pigments that play indispensable roles in plants and animals. The biosynthesis of carotenoids in plants is strictly regulated at the transcriptional and post-transcriptional levels in accordance with inherited genetic signals and developmental requirements and in response to external environmental stimulants. The alteration in the biosynthesis of carotenoids under the influence of external environmental stimulants, such as high light, drought, salinity, and chilling stresses, has been shown to significantly influence the nutritional value of crop plants. In addition to these stimulants, several pre- and postharvesting cultivation practices significantly influence carotenoid compositions and contents. Thus, this review discusses how various environmental stimulants and pre- and postharvesting factors can be positively modulated for the enhanced biosynthesis and accumulation of carotenoids in the edible parts of crop plants, such as the leaves, roots, tubers, flowers, fruit, and seeds. In addition, future research directions in this context are identified.

  10. Postharvest Exogenous Application of Abscisic Acid Reduces Internal Browning in Pineapple.

    Science.gov (United States)

    Zhang, Qin; Liu, Yulong; He, Congcong; Zhu, Shijiang

    2015-06-10

    Internal browning (IB) is a postharvest physiological disorder causing economic losses in pineapple, but there is no effective control measure. In this study, postharvest application of 380 μM abscisic acid (ABA) reduced IB incidence by 23.4-86.3% and maintained quality in pineapple fruit. ABA reduced phenolic contents and polyphenol oxidase and phenylalanine ammonia lyase activities; increased catalase and peroxidase activities; and decreased O2(·-), H2O2, and malondialdehyde levels. This suggests ABA could control IB through inhibiting phenolics biosynthesis and oxidation and enhancing antioxidant capability. Furthermore, the efficacy of IB control by ABA was not obviously affected by tungstate, ABA biosynthesis inhibitor, nor by diphenylene iodonium, NADPH oxidase inhibitor, nor by lanthanum chloride, calcium channel blocker, suggesting that ABA is sufficient for controlling IB. This process might not involve H2O2 generation, but could involve the Ca(2+) channels activation. These results provide potential for developing effective measures for controlling IB in pineapple.

  11. THE IMPACT OF ENVIRONMENTALLY FRIENDLY POSTHARVEST TREATMENTS ON THE ANTIOXIDANT ACTIVITY OF STRAWBERRY FRUITS DURING STORAGE

    Directory of Open Access Journals (Sweden)

    Ivna Štolfa

    2014-12-01

    Full Text Available Proper postharvest storage is an effective way to maintain the quality and nutritional values of fruits. The aim of this study was to determine how environmentally friendly postharvest treatments with salicylic acid solution, colloidal silver solution and ozone, affect the antioxidant activity of strawberry fruits (Fragaria x ananassa Duch. cv. Albion during 7 days of storage at 4°C. The content of ascorbic acid, total phenols and antioxidant activity of strawberry fruits were determined spec-trophotometrically. After 7 days of storage in strawberry fruits treated with all three treatments separately, the contents of ascorbic acid were higher than in the control fruits, supporting the usefulness of these treatments for preserving fruit quality and nutritional value during storage. The treatment with salicylic acid solution showed the most beneficial effect during storage causing a significant increase in the content of ascorbic acid, phenols and antioxidant activity at the end of the storage period.

  12. The in vitro culture of Phytophthora infestans isolates occurring on the tomato - their pathogenicity and usefulness for artificial inoculations

    Directory of Open Access Journals (Sweden)

    Elżbieta Horodecka

    2013-12-01

    Full Text Available In investigations on the fungus, Phytophthora infestans, isolated from open air, field-grown tomatoes, particular attention was paid to the pathogenicity of 32 isolates and the suitability of 10 kinds of natural media. It is concluded that Phytophthora races in Poland have highly varied pathogenicities and that they belong to race 0 or 1. The races were divided into subgroups of various aggressiveness. It was found that the best medium to obtain an inoculum was the agar-oat medium without vitamin B1. Vitamin B1 as well as tomatine added to agar media stimulated growth, but inhibited sporulation of Phytophthora infestans.

  13. Transcriptomic events associated with internal browning of apple during postharvest storage

    OpenAIRE

    Mellidou, Ifigeneia; Buts, Kim; Hatoum, Darwish; Ho, Quang Tri; Johnston, Jason W; Watkins, Christopher B; Schaffer, Robert J; Gapper, Nigel E; Giovannoni, Jim J; Rudell, David R; Hertog, Maarten LATM; Nicolai, Bart M

    2014-01-01

    Background Postharvest ripening of apple (Malus x domestica) can be slowed down by low temperatures, and a combination of low O2 and high CO2 levels. While this maintains the quality of most fruit, occasionally storage disorders such as flesh browning can occur. This study aimed to explore changes in the apple transcriptome associated with a flesh browning disorder related to controlled atmosphere storage using RNA-sequencing techniques. Samples from a browning-susceptible cultivar (‘Braeburn...

  14. [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

  15. Hydrogen Sulfide Alleviates Postharvest Senescence of Grape by Modulating the Antioxidant Defenses

    Directory of Open Access Journals (Sweden)

    Zhi-Jing Ni

    2016-01-01

    Full Text Available Hydrogen sulfide (H2S has been identified as an important gaseous signal in plants. Here, we investigated the mechanism of H2S in alleviating postharvest senescence and rotting of Kyoho grape. Exogenous application of H2S released from 1.0 mM NaHS remarkably decreased the rotting and threshing rate of grape berries. H2S application also prevented the weight loss in grape clusters and inhibited the decreases in firmness, soluble solids, and titratable acidity in grape pulp during postharvest storage. The data of chlorophyll and carotenoid content suggested the role of H2S in preventing chlorophyll breakdown and carotenoid accumulation in both grape rachis and pulp. In comparison to water control, exogenous H2S application maintained significantly higher levels of ascorbic acid and flavonoid and total phenolics and reducing sugar and soluble protein in grape pulp. Meanwhile, H2S significantly reduced the accumulation of malondialdehyde (MDA, hydrogen peroxide (H2O2, and superoxide anion (O2∙- in grape pulp. Further investigations showed that H2S enhanced the activities of antioxidant enzymes ascorbate peroxidase (APX and catalase (CAT and decreased those of lipoxygenase (LOX in both grape peels and pulp. In all, we provided strong evidence that H2S effectively alleviated postharvest senescence and rotting of Kyoho grape by modulating antioxidant enzymes and attenuating lipid peroxidation.

  16. Preharvest, harvest and postharvest factors inherent to roselle (Hibiscus sabdariffa L. crop: A review.

    Directory of Open Access Journals (Sweden)

    Balois-Morales, R.

    2016-01-01

    Full Text Available Hibiscus sabdariffa L. is cultivated to obtain fiber from the stems, oil from the seeds, and to harvest its calyces. Currently, there is a growing interest for the calyces due to studies that have proven their functional feature as the antioxidant effect, alluded to its anthocyanin content, and other benefits that expand their use to the pharmaceutical sector. However, there are no studies focused on relating all the factors involved in the process, from sowing and preharvest management, to harvest, postharvest management, distribution and the sale of dried calyces. The aim of this review is to highlight the factors involved in Roselle management such as variety, crop nutrition, sowing date, irrigation, plagues and diseases incidence and use of phytohormones. To establish the optimal time of calyces harvest, studies have been focused on determining aspects such as size, pH, dry matter content and anthocyanins at different times after blooming. As for the postharvest, the trend marked by studies is to implement improvements in the drying process of calyces and to let producers, distributors and sellers know the quality standards because much of the damage during postharvest is associated with deficiencies in the way calyces are handled.

  17. Effect of Calcium Chloride and Cooling on Post-Harvest Brussels Cabbage (Brassica Oleracea L.

    Directory of Open Access Journals (Sweden)

    Alfonso Rincón Pérez

    2014-11-01

    Full Text Available In recent years, the demand of crucifers has increased and particularly of Brussels sprouts (Brassica genus, species Brassica oleracea L.; mainly due to their functional properties; however, this vegetable is perishable and with inadequate techniques in postharvest handling, considerable losses are generated. The objective of this research was to determine the effect of calcium chloride and cooling on postharvest behavior of Brussels sprouts. A completely randomized design was performed, treatments corresponded to three storage temperatures (4°C, 8°C and temperature (18°C and three concentrations of calcium chloride (0%, 2% and 4% were used. Sprouts were harvested at commercial maturity on a farm irrigation district in Usochicamocha, Boyacá Department; of uniform size, excellent plant health and free from mechanical damage conditions. For 19 days of storage, weight loss, respiratory rate and total chlorophyll were measured. Sprouts stored at room temperature lasted 11days postharvest, while cooled lasted for 19 days. A significant effect in reducing weight loss between those sprouts which were stored at 4°C and 8°C and treated with calcium chloride solution at 4% was observed. For the respiratory rate was observed a significant reduction insprouts stored at 4°C. Therefore the most favorable temperature for the storage of Brussels sprouts is 4°C and calcium chloride solution 4%,useful information for producers and marketers.

  18. Ethylene Control Technologies in Extending Postharvest Shelf Life of Climacteric Fruit.

    Science.gov (United States)

    Zhang, Junhua; Cheng, Dong; Wang, Baobin; Khan, Iqbal; Ni, Yonghao

    2017-08-30

    Fresh fruit is important for a healthy diet. However, because of their seasonal production, regional specific cultivation, and perishable nature, it is essential to develop preservation technologies to extend the postharvest shelf life of fresh fruits. Climacteric fruit adopt spoilage because of ethylene, a key hormone associated with the ripening process. Therefore, controlling ethylene activity by following safe and effective approaches is a key to extend the postharvest shelf life of fruit. In this review, ethylene control technologies will be discussed aiming for the need of developing more innovative and effective approaches. The biosynthesis pathway will be given first. Then, the technologies determining the postharvest shelf life of climacteric fruit will be described with special attention to the latest and significant published works in this field. Special attention is given to 1-methylcyclopropene (1-MCP), which is effective in fruit preservation technologies. Finally, the encapsulation technology to improve the stability of 1-MCP will be proposed, using a potential encapsulation agent of 1-MCP, calixarene.

  19. Detection of Aflatoxin Producing Aspergillus flavus in Post-harvest Contaminated Vigna ungulculata Seeds

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Gautam

    2014-07-01

    Full Text Available The present study was carried out with a specific objective to study postharvest spoilage of Lobhiya (Vigna unguiculata seeds contaminated with Aspergillus flavus. Infected seeds were collected and cultured on potato dextrose agar (PDA media, at 25±2 °C. Aspergillus flavus isolates were primarily characterized by its morphological and microscopic characteristics. Collected fungal isolates were also screened for their afaltoxigenic nature on preliminary basis and at molecular level. For preliminary screening, 5 mm disc of fungal culture was soaked with few drops of liquid ammonia. Color change from yellow pigment to plum-red with different intensities showed the mycotoxic nature of the fungus. DNA from fungal isolates was isolated and amplified using PCR with aflatoxin specific primers, apa-2, ver-1 and omt-1. Amplicons of 1032 bp, 895 bp and 596 bp were obtained in most of the isolates regardless of primer set used which was useful to differentiate between mycotoxic and nontoxic isolates of A. flavus. The isolation of aflatoxigenic strains of A. flavus during post-harvest period of lobhiya seeds raise a serious concern over the quality of seeds and a threat to heath of consumers. It was concluded that Aspergillus flavus is responsible for postharvest spolilage of Lobhiya (Vigna unguiculata.

  20. Effect of chitosan and its derivatives as antifungal and preservative agents on postharvest green asparagus.

    Science.gov (United States)

    Qiu, Miao; Wu, Chu; Ren, Gerui; Liang, Xinle; Wang, Xiangyang; Huang, Jianying

    2014-07-15

    The antifungal activity and effect of high-molecular weight chitosan (H-chitosan), low-molecular weight chitosan (L-chitosan) and carboxymethyl chitosan (C-chitosan) coatings on postharvest green asparagus were evaluated. L-chitosan and H-chitosan efficiently inhibited the radial growth of Fusarium concentricum separated from postharvest green asparagus at 4 mg/ml, which appeared to be more effective in inhibiting spore germination and germ tube elongation than that of C-chitosan. Notably, spore germination was totally inhibited by L-chitosan and H-chitosan at 0.05 mg/ml. Coated asparagus did not show any apparent sign of phytotoxicity and maintained good quality over 28 days of cold storage, according to the weight loss and general quality aspects. Present results inferred that chitosan could act as an attractive preservative agent for postharvest green asparagus owing to its antifungal activity and its ability to stimulate some defense responses during storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Chitosan controls postharvest anthracnose in bell pepper by activating defense-related enzymes.

    Science.gov (United States)

    Edirisinghe, Madushani; Ali, Asgar; Maqbool, Mehdi; Alderson, Peter G

    2014-12-01

    Anthracnose, a postharvest disease caused by the fungus Colletotrichum capsici is the most devastating disease of bell pepper that causes great economic losses especially in tropical climates. Therefore, the objective of this study was to evaluate the antifungal properties of chitosan (low molecular weight from crab shell, Mw: 50 kDa and 75-85 % deacetylated) against anthracnose by inducing defense-related enzymes. The concentrations of 0, 0.5, 1.0, 1.5 and 2.0 % chitosan were used to control the fungus in vitro and postharvest. There was a reduction in C. capsici mycelial growth and the highest chitosan concentration (2.0 %) reduced the growth by 70 % after 7 days incubation. In germination test, the concentration of 1.5 and 2.0 % chitosan reduced spore germination in C. capsici between 80 % and 84 %, respectively. In postharvest trial the concentration of 1.5 % decreased the anthracnose severity in pepper fruit by approximately 76 % after 28 days of storage (10 ± 1 °C; 80 % RH). For enzymatic activities, the concentration of 1.5 and 2.0 % chitosan increased the polyphenol oxidase (PPO), peroxidase (POD) and total phenolics in inoculated bell pepper during storage. Based on these results, the chitosan presents antifungal properties against C. capsici, as well as potential to induce resistance on bell pepper.

  2. Efficiency of a yeast-based formulation for the biocontrol of postharvest anthracnose of papayas

    Directory of Open Access Journals (Sweden)

    Jaqueline Rabelo de Lima

    2014-09-01

    Full Text Available To identify formulations of biological agents that enable survival, stability and a good surface distribution of the antagonistic agent, studies that test different application vehicles are necessary. The efficiency of two killer yeasts, Wickerhamomyces anomalus (strain 422 and Meyerozyma guilliermondii (strain 443, associated with five different application vehicles, was assessed for the protection of postharvest papayas. In this study, after 90 days of incubation at 4ºC, W. anomalus (strain 422 and M. guilliermondii (strain 443 were viable with all application vehicles tested. Fruits treated with different formulations (yeasts + application vehicles had a decreased severity of disease (by at least 30% compared with untreated fruits. The treatment with W. anomalus (strain 422 + 2% starch lowered disease occurrence by 48.3%. The most efficient treatments using M. guilliermondii (strain 443 were those with 2% gelatin or 2% liquid carnauba wax, both of which reduced anthracnose by 50% in postharvest papayas. Electron micrographs of the surface tissues of the treated fruits showed that all application vehicles provided excellent adhesion of the yeast to the surface. Formulations based on starch (2%, gelatin (2% and carnauba wax (2% were the most efficient at controlling fungal diseases in postharvest papayas.

  3. Ice immersion as a postharvest treatment of oysters for the reduction of Vibrio vulnificus.

    Science.gov (United States)

    Quevedo, Ana C; Smith, James G; Rodrick, Gary E; Wright, Anita C

    2005-06-01

    Vibrio vulnificus produces serious illnesses that are commonly associated with shellfish consumption, particularly raw oysters. Ingestion can result in fatal septicemia in susceptible individuals with hepatitis, cirrhosis, immune dysfunction, diabetes, or hemochromatosis (metabolic iron overload). Therefore, postharvest treatments to reduce vibrio levels in oysters have been recommended. In this study, rapid chilling by immersion of unwashed whole oysters in ice for 3 h was assessed as a postharvest treatment for reduction of V. vulnificus. Treated oysters were subsequently refrigerated at 45 degrees F (7.2 degrees C), whereas control oysters were not iced but were maintained at 45 degrees F throughout the study. Homogenized meats were monitored for total heterotrophic aerobic bacteria, V. vulnificus, and fecal coliform content before and after treatment over a 2-week period. V. vulnificus was enumerated by DNA probe hybridization of colonies from standard plate counts on nonselective medium, and recovery was compared for several media. Loss of plating efficiency was observed on standard selective and differential media compared with nonselective agars. Numbers of V. vulnificus generally declined in treated samples compared with controls; however, increases in total heterotrophic bacteria and fecal coliforms were also observed in treated samples at some time points. This study does not support the use of ice immersion as a postharvest method because of the relatively small declines in V. vulnificus numbers and the possibility of concomitant increases in fecal coliform and total bacterial contamination.

  4. THE ROLE OF POSTHARVEST MACHINERIES AND PACKAGING IN MINIMIZING AFLATOXIN CONTAMINATION IN PEANUT

    Directory of Open Access Journals (Sweden)

    Raffi Paramawati

    2016-10-01

    Full Text Available As a tropical country with relatively high humidity and temperature, Indonesia is struggling with aflatoxin which frequently contaminates peanut. Aflatoxin is a carcinogenic toxic substance that could cause liver cancer. Due to the increasing concern on food safety, the Indonesian Drugs and Foods Agency specifies the maximum aflatoxin allowed in peanut as much as 20 ppb. However, researches showed that aflatoxin contamination in peanut in Indonesia is much higher than the threshold. The study was carried out to observe the effect of using postharvest machineries and packaging  treatments on aflatoxin contamination in peanut. Reduction of postharvest processes was conducted by using series of machineries, e.g. thresher, dryer, and sheller. Packaging treatments, e.g. vacuum plastic pack, hermetic glass chamber, and polyethylene (PE plastic wrap were carried out during storage at ambient temperature (25-27°C. The results showed that using machineries in postharvest handling produced peanut free from aflatoxin contamination. However, without effective packaging, the aflatoxin level would increase during storage. Hermetic packaging could protect peanut from the mold as indicated by low level of aflatoxin contamination.

  5. Protein changes in the albedo of citrus fruits on postharvesting storage.

    Science.gov (United States)

    Lliso, Ignacio; Tadeo, Francisco R; Phinney, Brett S; Wilkerson, Curtis G; Talón, Manuel

    2007-10-31

    In this work, major protein changes in the albedo of the fruit peel of Murcott tangor (tangerine x sweet orange) during postharvest ageing were studied through 2D PAGE. Protein content in matured on-tree fruits and in fruits stored in nonstressing [99% relative humidity (RH) and 25 degrees C], cold (99% RH and 4 degrees C), and drought (60% RH and 25 degrees C) conditions was initially determined. Protein identification through MS/MS determinations revealed in all samples analyzed the occurrence of manganese superoxide dismutase (Mn SOD), actin, ATP synthase beta subunit (ATPase), citrus salt-stress associated protein (CitSap), ascorbate peroxidase (APX), translationally controlled tumor protein (TCTP), and a cysteine proteinase (CP) of the papain family. The latter protein was identified in two different gel spots, with different molecular mass, suggesting the simultaneous presence of the proteinase precursor and its active form. While Mn SOD, actin, ATPase, and CitSap were unchanged in the assayed conditions, TCTP and APX were downregulated during the postharvest ageing process. Ageing-induced APX repression was also reversed by drought. CP contents in albedo, which were similar in on- and off-tree fruits, were strongly dependent upon cold storage. The active/total CP protein ratio significantly increased after cold exposure. This proteomic survey indicates that major changes in protein content in the albedo of the peel of postharvest stored citrus fruits are apparently related to the activation of programmed cell death (PCD).

  6. Asparagus chain: Fifth year production of different genotypes and postharvest behaviour.

    Directory of Open Access Journals (Sweden)

    Erika Kirschenbilder

    2015-01-01

    Full Text Available The objective of this investigation was to study greenhouse precocious spears yield of three genotypes of asparagus on its fifth harvest season. The trial was established at the Faculty of Agricultural, Pontifical Catholic University of Argentina, on November, 15, 2006. 19 different harvests were made from 04/09/2012 to 22/10/2012, one every two days. A multifactor ANOVA-LSD test (P>0.05 was performed. Variables analyzed were: total productivity and commercial productivity (PFT and PFC, total number of spears and commercial number of spears (NTT and NTC; caliber distribution (DC: Jumbo (J, Extra-Large (XL, Large (L, Medium (M and Small (S and finally, quality defects (D: spiked spears (TE; short spears (TC and other defects (OD. During the post-harvest period, bundles (A, trays (BA and polyethylene bags were used to study fresh weight evolution (EPF; daily fresh weight loss (PPFD and average fresh weight during the post-harvest period (PPFP. Italian breeds yielded above 9 t/ha, twice the Argentinean national average. According to the production results, Giove stood out regarding PFT, PFC, NTT, NTC and a proper DC, where the 70% of spears measured L and XL. With regard to postharvest behavior, it was found that the lowest degree of dehydration was obtained by using bags and trays.

  7. Long-term effect of inoculum pretreatment on fermentative hydrogen production by repeated batch cultivations: homoacetogenesis and methanogenesis as competitors to hydrogen production

    DEFF Research Database (Denmark)

    Luo, Gang; Karakashev, Dimitar Borisov; Xie, Li

    2011-01-01

    Long-term effects of inoculum pretreatments(heat, acid, loading-shock) on hydrogen production from glucose under different temperatures (378C, 558C) and initial pH (7 and 5.5) were studied by repeated batch cultivations. Results obtained showed that it was necessary to investigate the long......-term effect of inoculum pretreatment on hydrogen production since pretreatments may just temporarily inhibit the hydrogen consuming processes. After long-term cultivation, pretreated inocula did not enhance hydrogen production compared to untreated inocula under mesophilic conditions (initial pH 7 and pH 5.......5) and thermophilic conditions (initial pH 7). However, pretreatment could inhibit lactate production and lead to higher hydrogen yield under thermophilic conditions at initial pH 5.5. The results further demonstrated that inoculum pretreatment could not permanently inhibit either methanogenesis or homoacetogenesis...

  8. AMPK in Pathogens

    OpenAIRE

    Mesquita, Inês Morais; Moreira, Diana; Marques, Belém Sampaio; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo Jorge Leal

    2016-01-01

    During host–pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recogn...

  9. Current strategies in the farm practices and post-harvest pesticidal defence

    Directory of Open Access Journals (Sweden)

    Luciano Suss

    2008-04-01

    Full Text Available Today, people often talk about biologic agriculture and Integrated Production (IP, even if the real meaning of these terms is altered. In both cases, they deal with production methods characterized by a particular attention to the reduction of the environmental impact of all the farm practices used, especially for defence from adversities, being the element of major concern for environment and consumers’ health.Farm practice evolution, especially those about pest defence, is based on important conceptual change, accurate scientific analysis and organization of technical assistance, rationalization of agri-pharmaceutical product use is one of the main objective of Integrated Production Specifications (IPS. The quantitative reduction is the first objective, obtained by various means such as the use of efficient equipment and the qualitative selection based on the priority use of minor impact means, effectiveness being equal. At post-harvest, the anti-parasitary defence is undergoing deep changes in our country. Once, pesticides very toxic and persistent were used; however, in the last years the availability of active principles (a.p. usable on foodstuffs or in productive environments; for instance, methyl bromide use has been progressively reduced till its banishment because it is recognized to damage the ozone layer. Thus, on the whole we can talk about “integrated pest management” even for the post-harvest sector. However, substantial differences exist between agriculture and post-harvest, thus the integrated pest management in food production environment has to be designed in a different way. The fundamental element of this technique is to identify a tolerance threshold to pest attack but for the defence of food industries and stored foodstuffs is very difficult, if not impossible, to fix a limit to insect presence after which intervening is compulsory. Monitoring of pest attacks and the implementation of prevention practices is

  10. Modeling the vacuolar storage of malate shed lights on pre- and post-harvest fruit acidity.

    Science.gov (United States)

    Etienne, Audrey; Génard, Michel; Lobit, Philippe; Bugaud, Christophe

    2014-11-18

    Malate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. Several studies suggest that malate accumulation in fruit cells is controlled at the level of vacuolar storage. However, the regulation of vacuolar malate storage throughout fruit development, and the origins of the phenotypic variability of the malate concentration within fruit species remain to be clarified. In the present study, we adapted the mechanistic model of vacuolar storage proposed by Lobit et al. in order to study the accumulation of malate in pre and postharvest fruits. The main adaptation concerned the variation of the free energy of ATP hydrolysis during fruit development. Banana fruit was taken as a reference because it has the particularity of having separate growth and post-harvest ripening stages, during which malate concentration undergoes substantial changes. Moreover, the concentration of malate in banana pulp varies greatly among cultivars which make possible to use the model as a tool to analyze the genotypic variability. The model was calibrated and validated using data sets from three cultivars with contrasting malate accumulation, grown under different fruit loads and potassium supplies, and harvested at different stages. The model predicted the pre and post-harvest dynamics of malate concentration with fairly good accuracy for the three cultivars (mean RRMSE = 0.25-0.42). The sensitivity of the model to parameters and input variables was analyzed. According to the model, vacuolar composition, in particular potassium and organic acid concentrations, had an important effect on malate accumulation. The model suggested that rising temperatures depressed malate accumulation. The model also helped distinguish differences in malate concentration among the three cultivars and between the pre and post-harvest stages by highlighting the probable importance of proton pump activity and particularly of the free

  11. Synergism of cattle and bison inoculum on ruminal fermentation and select bacterial communities in an artificial rumen (Rusitec fed barley straw

    Directory of Open Access Journals (Sweden)

    Daniela B Oss

    2016-12-01

    Full Text Available This study evaluated the effect of increasing the proportion of bison relative to cattle inoculum on fermentation and microbial populations within an artificial rumen (Rusitec. The experiment was a completely randomized design with a factorial treatment structure (proportion cattle:bison inoculum; 0:100, 33:67, 67:33 and 100:0 replicated in two Rusitec apparatuses (n=8 fermenters. The experiment was 15 d with 8 d of adaptation and 7 d of sampling. Fermenters were fed a diet of 70:30 barley straw:concentrate (DM basis. True digestibility of DM was determined after 48 h of incubation from d 13-15, and daily ammonia (NH3 and volatile fatty acid (VFA production were measured on d 9-12. Protozoa counts were determined at d 9, 11, 13 and 15 and particle-associated bacteria (PAB from d 13-15. Select bacterial populations in the PAB were measured using RT-qPCR. Fermenter was considered the experimental unit and day of sampling as a repeated measure. Increasing the proportion of bison inoculum resulted in a quadratic effect (P0.05. Increasing bison inoculum linearly increased (P<0.05 concentrate aNDF disappearance, total and concentrate N disappearance as well as total daily VFA and acetate production. A positive quadratic response (P<0.05 was observed for daily NH3-N, propionate, butyrate, valerate, isovalerate and isobutyrate production, as well as the acetate:propionate ratio. Increasing the proportion of bison inoculum linearly increased (P<0.05 total protozoa numbers. No effects were observed on pH, total gas and methane production, microbial N synthesis, or copies of 16S rRNA associated with total bacteria, Selenomonas ruminantium or Prevotella bryantii. Increasing bison inoculum had a quadratic effect (P<0.05 on Fibrobacter succinogenes, and tended to linearly (P<0.10 increase Ruminococcus flavefaciens and decrease (P<0.05 Ruminococcus albus copy numbers. In conclusion, bison inoculum increased the degradation of feed protein and fibre. A mixture

  12. Black pod: diverse pathogens with a global impact on cocoa yield.

    Science.gov (United States)

    Guest, David

    2007-12-01

    ABSTRACT Pathogens of the Straminipile genus Phytophthora cause significant disease losses to global cocoa production. P. megakarya causes significant pod rot and losses due to canker in West Africa, whereas P. capsici and P. citrophthora cause pod rots in Central and South America. The global and highly damaging P. palmivora attacks all parts of the cocoa tree at all stages of the growing cycle. This pathogen causes 20 to 30% pod losses through black pod rot, and kills up to 10% of trees annually through stem cankers. P. palmivora has a complex disease cycle involving several sources of primary inoculum and several modes of dissemination of secondary inoculum. This results in explosive epidemics during favorable environmental conditions. The spread of regional pathogens must be prevented by effective quarantine barriers. Resistance to all these Phytophthora species is typically low in commercial cocoa genotypes. Disease losses can be reduced through integrated management practices that include pruning and shade management, leaf mulching, regular and complete harvesting, sanitation and pod case disposal, appropriate fertilizer application and targeted fungicide use. Packaging these options to improve uptake by smallholders presents a major challenge for the industry.

  13. Pathogenicity of Neonectria fuckeliana on Norway Spruce Clones in Sweden and Potential Management Strategies

    Directory of Open Access Journals (Sweden)

    Martin Pettersson

    2018-02-01

    Full Text Available The fungus Neonectria fuckeliana has become an increasing problem on Norway spruce (Picea abies in the Nordic countries during recent years. Canker wounds caused by the pathogen reduce timber quality and top-dieback is a problem for the Christmas tree industry. In this study, four inoculation trials were conducted to examine the ability of N. fuckeliana to cause disease on young Norway spruce plants and determine how different wound types would affect the occurrence and severity of the disease. Symptom development after 8–11 months was mainly mild and lesion lengths under bark were generally minor. However, N. fuckeliana could still be reisolated and/or molecularly detected. Slow disease development is in line with older studies describing N. fuckeliana as a weak pathogen. However, the results do not explain the serious increased damage by N. fuckeliana registered in Nordic forests and Christmas tree plantations. Potential management implications, such as shearing Christmas trees during periods of low inoculum pressure, cleaning secateurs between trees, and removal and burning of diseased branches and trees to avoid inoculum transfer and to keep disease pressure low, are based on experiments presented here and experiences with related pathogens.

  14. The pathogenicity of thymidine kinase-deficient mutants of herpes simplex virus in mice.

    Science.gov (United States)

    Field, H J; Wildy, P

    1978-10-01

    The pathogenicity for mice of two mutants of herpes simplex virus (type 1 and type 2), which fail to induce thymidine kinase, were compared with their respective parent strains. The mutants were much less virulent than the parents following either intracerebral or peripheral inoculation. The replication of the virus at the site of inoculation and its progression into the nervous system were studied. Following a very large inoculum in the ear, the type 1 mutant was found to establish a latent infection in the cervical dorsal root ganglia. Mice inoculated intracerebrally with small doses of the mutant viruses were solidly immune to challenge with lethal doses of the parent strain.

  15. Optimization of inoculum to substrate ratio for bio-energy generation in co-digestion of tannery solid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sri Bala Kameswari, K.; Chitra Kalyanaraman,; Porselvam, S. [Central Leather Research Institute (CLRI), Environmental Technology Division, Chennai (India); Thanasekaran, K. [Anna University, Centre for Environmental Studies, Chennai (India)

    2012-04-15

    The inoculum to substrate (I/S) ratio is an important factor which influences the anaerobic digestion process. In this study, the effect of different I/S ratios on the performance of co-digestion of fleshings along with mixture of sludge generated during treatment of tannery wastewater was investigated. The parameters studied were biogas generation, volatile solids reduction, volatile fatty acid (VFA) production, and the stability of the digestion process based on VFA to alkalinity ratio was evaluated for various I/S ratios. Economical significance of I/S ratio as related to the volume of the anaerobic digester and the potential benefit of bio-energy generated are discussed in detail. (orig.)

  16. A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits.

    Science.gov (United States)

    Etienne, Audrey; Génard, Michel; Bugaud, Christophe

    2015-01-01

    Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity.

  17. A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits.

    Directory of Open Access Journals (Sweden)

    Audrey Etienne

    Full Text Available Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity.

  18. Reversibility of neurofilamentous inclusion formation following repeated sublethal intracisternal inoculums of AlCl3 in New Zealand white rabbits.

    Science.gov (United States)

    Strong, M J; Gaytan-Garcia, S; Jakowec, D M

    1995-01-01

    In this report, we describe the clinical, topographical and immunohistochemical characteristics of neurofilament (NF) inclusion formation induced by the intracisternal inoculation of young adult New Zealand white rabbits at 28-day intervals with 100 micrograms AlCl3 over the course of 267 days. The ability to recover following cessation of aluminum exposure has also been assessed. The extent of neurofilamentous inclusion formation was proportionate to the cumulative amount of AlCl3 inoculated and initially consisted of fusiform axonal distention in the ventral spinal cord at day 51 following the initial inoculum. Spinal motor neuron perikaryal inclusions and discrete axonal spheroids were observed at day 107 and supraspinal neurofilamentous pathology by day 156. Perikaryal inclusions were immunoreactive to antibodies recognizing both poorly phosphorylated (SMI 32) and more highly phosphorylated high molecular weight NF (NFH). In contrast, axonal spheroids were intensely immunoreactive at all stages with antibodies recognizing highly phosphorylated NFH and an age-dependent NFH phosphorylation state (SMI 34) with only faint SMI 32 immunoreactivity. Immunoreactivity to an antibody recognizing ubiquitin-protein conjugates did not appear until day 156, whereas inclusions were not immunoreactive to antibodies recognizing either phosphatase-dependent or -independent microtubule-associated protein tau at any stage. Upon withdrawal from further AlCl3 exposure after intervals of 51, 107 or 156 days following the initial inoculum, clinical recovery ensued in all rabbits. In all but the most severely affected rabbits, perikaryal neurofilamentous inclusions resolved. However, axonal spheroids continued to be prominent. These studies demonstrate that the repetitive intracisternal inoculation of AlCl3 in New Zealand white rabbits induces a reversible process of neurofilamentous inclusion formation that preferentially affects motor neurons, and in which recovery will occur in

  19. Control of bull’s-eye rot of apple caused by Neofabraea perennans and Neofabraea kienholzii using pre- and postharvest fungicides

    Science.gov (United States)

    Bull’s-eye rot is a major postharvest disease of apple caused by several fungi belonging to the Neofabraea and Phlyctema genera. Chemical control of these fungi is a crucial component of disease management for apples that are conventionally grown. The efficacy of several pre-harvest and postharvest ...

  20. Feasibility of a network of excellence postharvest food losses : combining knowledge and competences to reduce food losses in developing and emerging economies

    NARCIS (Netherlands)

    Gogh, van J.B.; Aramyan, L.H.; Sluis, van der A.A.; Soethoudt, J.M.; Scheer, F.P.

    2013-01-01

    Motivation: food security & postharvest losses Fruits and vegetables supply chains in developing countries are characterised by relatively high losses between harvest and consumption. In general, the postharvest system includes all stages in the chain where the activity/service is intended to

  1. Utilization of inoculum of AM fungi produced on-farm for the production of Capsicum annuum: a summary of 7 years of field trials on a conventional vegetable farm

    Science.gov (United States)

    Utilization of arbuscular mycorrhizal [AM] fungus inoculum has been encouraged as a way for vegetable farmers to better utilize the AM symbiosis. On-farm systems can economically produce inoculum that has been shown to increase the yield of specific crops. We conducted seven years of field studies...

  2. Pre-acclimation of a wastewater inoculum to cellulose in an aqueous–cathode MEC improves power generation in air–cathode MFCs

    KAUST Repository

    Cheng, Shaoan; Kiely, Patrick; Logan, Bruce E.

    2011-01-01

    -cathode MFCs with this inoculum produced maximum power densities of 1070mWm-2 (cathode surface area) in single-chamber and 880mWm-2 in two-chamber MFCs. Coulombic efficiencies ranged from 25% to 50%, and COD removals were 50-70% based on total cellulose

  3. Fermentation of Ammonia Fiber Expansion Treated and Untreated Barley Straw in a Rumen Simulation Technique using Rumen Inoculum from Cattle with Slow Versus Fast Rate of Fiber Disappearance

    Directory of Open Access Journals (Sweden)

    Karen Ann Beauchemin

    2016-11-01

    Full Text Available The purpose of this study was to determine the effect of rumen inoculum from heifers with fast vs. slow rate of in situ fiber digestion on the fermentation of complex versus easily digested fiber sources in the forms of untreated and Ammonia Fiber Expansion (AFEX treated barley straw, respectively, using an artificial rumen simulation technique (Rusitec. In situ fiber digestion was measured in a previous study by incubating untreated barley straw in the rumen of sixteen heifers fed a diet consisting of 700 g/kg barley straw and 300 g/kg concentrate. The two heifers with fastest rate of digestion (Fast > 4.18 % h-1 and the two heifers with the slowest rate of digestion (Slow 0.05 methane per gram of digested material for both untreated and AFEX straw, and reduced (interaction, P < 0.05 acetate: propionate ratio for untreated straw. Greater relative populations of Ruminococcus albus (P < 0.05 and increased microbial N production (P = 0.045 were observed in Fast rumen inoculum. AFEX straw in Fast inoculum had greater total bacterial populations than Slow, but for untreated straw this result was reversed (interaction, P = 0.013. These findings indicate that differences in microbial populations in rumen fluid contribute to differences in the capacity of rumen inoculum to digest fiber.

  4. Influence of carbon source and inoculum type on anaerobic biomass adhesion on polyurethane foam in reactors fed with acid mine drainage.

    Science.gov (United States)

    Rodriguez, Renata P; Zaiat, Marcelo

    2011-04-01

    This paper analyzes the influence of carbon source and inoculum origin on the dynamics of biomass adhesion to an inert support in anaerobic reactors fed with acid mine drainage. Formic acid, lactic acid and ethanol were used as carbon sources. Two different inocula were evaluated: one taken from an UASB reactor and other from the sediment of a uranium mine. The values of average colonization rates and the maximum biomass concentration (C(max)) were inversely proportional to the number of carbon atoms in each substrate. The highest C(max) value (0.35 g TVS g(-1) foam) was observed with formic acid and anaerobic sludge as inoculum. Maximum colonization rates (v(max)) were strongly influenced by the type of inoculum when ethanol and lactic acid were used. For both carbon sources, the use of mine sediment as inoculum resulted in a v(max) of 0.013 g TVS g(-1) foam day(-1), whereas 0.024 g TVS g(-1) foam day(-1) was achieved with anaerobic sludge. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Application of Biofilm Covered Activated Carbon Particles as a Microbial Inoculum Delivery System for Enhanced Bioaugmentation of PCBs in Contaminated Sediment

    Science.gov (United States)

    2013-09-01

    after anaerobic digestion at thermophilic conditions (60- 70C). Application of biofilm covered activated carbon particles as a microbial inoculum...Sludge Thickener; Sludge = Sludge after anaerobic digestion at thermophilic conditions (60- 70C). C3. Microscopic evaluation of dechlorinating...associated enzymes are capable of opening the biphenyl ring structure and transform the molecule into a linear structure, this changed structure was not

  6. Use of starter cultures of lactic acid bacteria and yeasts as inoculum enrichment for the production of gowé, a sour beverage from Benin

    DEFF Research Database (Denmark)

    Vieira-Dalodé, G.; Madodé, Y.E.; Hounhouigan, J.

    2008-01-01

    Lactobacillus fermentum, Weissella confusa, Kluyveromyces marxianus and Pichia anomala, previously isolated during natural fermentation of traditional gowé, were tested as inoculum enrichment for controlled fermentation of gowé. The final product was subjected to chemical analysis and sensory eva...

  7. Using an on-line UV-C apparatus to treat harvested fruit for controlling postharvest decay

    International Nuclear Information System (INIS)

    Wilson, C.L.; Upchurch, B.; El Ghaouth, A.; Stevens, C.; Khan, V.; Droby, S.; Chalutz, E.

    1997-01-01

    An apparatus was designed to deliver low-dose UV-C light to the surface of fruit on a processing line and tested for its control of postharvest decay. It consisted of a row of UV-C emitting lamps mounted on a frame above a conveyer belt that transported the fruit. The dosage of the UV-C light delivered to the fruit surface was regulated by varying the speed of the conveyor belt. Postharvest decay after 28 days storage of 'Empire' apples was reduced 52% relative to the untreated checks when the fruit were conveyed at 6.2 m · min -1 (1.38 kJ · m -2 dose) under the UV-C apparatus. Factors affecting the practical application of UV-C irradiation of fruit for controlling postharvest decay are discussed

  8. A novel aspartic acid protease gene from pineapple fruit (Ananas comosus): cloning, characterization and relation to postharvest chilling stress resistance.

    Science.gov (United States)

    Raimbault, Astrid-Kim; Zuily-Fodil, Yasmine; Soler, Alain; Cruz de Carvalho, Maria H

    2013-11-15

    A full-length cDNA encoding a putative aspartic acid protease (AcAP1) was isolated for the first time from the flesh of pineapple (Ananas comosus) fruit. The deduced sequence of AcAP1 showed all the common features of a typical plant aspartic protease phytepsin precursor. Analysis of AcAP1 gene expression under postharvest chilling treatment in two pineapple varieties differing in their resistance to blackheart development revealed opposite trends. The resistant variety showed an up-regulation of AcAP1 precursor gene expression whereas the susceptible showed a down-regulation in response to postharvest chilling treatment. The same trend was observed regarding specific AP enzyme activity in both varieties. Taken together our results support the involvement of AcAP1 in postharvest chilling stress resistance in pineapple fruits. Copyright © 2013 Elsevier GmbH. All rights reserved.

  9. Fecundity compensation and tolerance to a sterilizing pathogen in Daphnia.

    Science.gov (United States)

    Vale, P F; Little, T J

    2012-09-01

    Hosts are armed with several lines of defence in the battle against parasites: they may prevent the establishment of infection, reduce parasite growth once infected or persevere through mechanisms that reduce the damage caused by infection, called tolerance. Studies on tolerance in animals have focused on mortality, and sterility tolerance has not been investigated experimentally. Here, we tested for genetic variation in the multiple steps of defence when the invertebrate Daphnia magna is infected with the sterilizing bacterial pathogen Pasteuria ramosa: anti-infection resistance, anti-growth resistance and the ability to tolerate sterilization once infected. When exposed to nine doses of a genetically diverse pathogen inoculum, six host genotypes varied in their average susceptibility to infection and in their parasite loads once infected. How host fecundity changed with increasing parasite loads did not vary between genotypes, indicating that there was no genetic variation for this measure of fecundity tolerance. However, genotypes differed in their level of fecundity compensation under infection, and we discuss how, by increasing host fitness without targeting parasite densities, fecundity compensation is consistent with the functional definition of tolerance. Such infection-induced life-history shifts are not traditionally considered to be part of the immune response, but may crucially reduce harm (in terms of fitness loss) caused by disease, and are a distinct source of selection on pathogens. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  10. Influence of inoculum density on population dynamics and dauer juvenile yields in liquid culture of biocontrol nematodes Steinernema carpocapsae and S. feltiae (Nematoda: Rhabditida).

    Science.gov (United States)

    Hirao, Ayako; Ehlers, Ralf-Udo

    2010-01-01

    For improvement of mass production of the rhabditid biocontrol nematodes Steinernema carpocapsae and Steinernema feltiae in monoxenic liquid culture with their bacterial symbionts Xenorhabdus nematophila and Xenorhabdus bovienii, respectively, the effect of the initial nematode inoculum density on population development and final concentration of dauer juveniles (DJs) was investigated. Symbiotic bacterial cultures are pre-incubated for 1 day prior to inoculation of DJs. DJs are developmentally arrested and recover development as a reaction to food signals provided by their symbionts. After development to adults, the nematodes produce DJ offspring. Inoculum density ranged from 1 to 10 x 10(3) DJ per milliliter for S. carpocapsae and 1 to 8 x 10(3) DJs per milliliter for S. feltiae. No significant influence of the inoculum density on the final DJ yields in both nematode species was recorded, except for S. carpocapsae cultures with a parental female density 300 for S. carpocapsae and almost 200 for S. feltiae. The compensative adaptation of fecundity to nematode population density is responsible for the lack of an inoculum (or parental female) density effect on DJ yields. At optimal inoculation density of S. carpocapsae, offspring were produced by the parental female population, whereas S. feltiae always developed a F1 female population, which contributed to the DJ yields and was the reason for a more scattered distribution of the yields. The F1 female generation was accompanied by a second peak in X. bovienii density. The optimal DJ inoculum density for S. carpocapsae is 3-6 x 10(3) DJs per milliliter in order to obtain >10(3) parental females per milliliter. Density-dependent effects were neither observed on the DJ recovery nor on the sex ratio in the parental adult generation. As recovery varied between different batches, assessment of the recovery of inoculum DJ batches is recommended. S. feltiae was less variable in DJ recovery usually reaching >90%. The

  11. Effect of photo-selective nettings on post-harvest quality and bioactive compounds in selected tomato cultivars.

    Science.gov (United States)

    Selahle, Maphoko Kamogelo; Sivakumar, Dharini; Soundy, Puffy

    2014-08-01

    Photo-selective coloured netting is referred to as a 'new agro-technological' concept adopted to manipulate light quality changes that can induce favourable responses in plants. Tomato (Solanum lycopersicum L.) cultivars AlvaV, Irit and SCX 248 grown under the black net (commercial net, 25% shading) showed higher weight loss, loss of firmness, ascorbic acid content and decline in the ratio of soluble solids content/titrable acidity during post-harvest storage (low-temperature storage at 10°C and 90% relative humidity for 21 days followed by market shelf conditions at 25°C for 2 days). During post-harvest storage, lycopene, β-carotene, total phenolic content and antioxidant scavenging activity were higher in cvs AlfaV and Irit grown under the black or pearl nets. However, the β-carotene, total phenolic content and antioxidant scavenging activity were higher in SCX 248 grown under the red net during post-harvest storage. Cultivar AlfaV grown under the red and pearl nets had a higher number of odour active aroma compounds during post-harvest storage. Panellists preferred cv. AlfaV grown under the pearl nets after storage based on taste, overall appearance and firm textured fruits. Pearl photo-selective nets retained the overall fruit quality and bioactive components in cvs AlfaV and Irit during post-harvest storage. Red photo-selective nets, however, showed greater influence on retention of overall fruit quality and bioactive compounds in cv. SCX 248 during post-harvest storage. © 2013 Society of Chemical Industry.

  12. Methyl Jasmonate and 1-Methylcyclopropene Treatment Effects on Quinone Reductase Inducing Activity and Post-Harvest Quality of Broccoli

    Science.gov (United States)

    Ku, Kang Mo; Choi, Jeong Hee; Kim, Hyoung Seok; Kushad, Mosbah M.; Jeffery, Elizabeth H.; Juvik, John A.

    2013-01-01

    Effect of pre-harvest methyl jasmonate (MeJA) and post-harvest 1-methylcyclopropene (1-MCP) treatments on broccoli floret glucosinolate (GS) concentrations and quinone reductase (QR, an in vitro anti-cancer biomarker) inducing activity were evaluated two days prior to harvest, at harvest and at 10, 20, and 30 days of post-harvest storage at 4 °C. MeJA treatments four days prior to harvest of broccoli heads was observed to significantly increase floret ethylene biosynthesis resulting in chlorophyll catabolism during post-harvest storage and reduced product quality. Post-harvest treatment with 1-methylcyclopropene (1-MCP), which competitively binds to protein ethylene receptors, maintained post-harvest floret chlorophyll concentrations and product visual quality in both control and MeJA-treated broccoli. Transcript abundance of BoPPH, a gene which is responsible for the synthesis of pheophytinase, the primary enzyme associated with chlorophyll catabolism in broccoli, was reduced by 1-MCP treatment and showed a significant, negative correlation with floret chlorophyll concentrations. The GS, glucobrassicin, neoglucobrassicin, and gluconasturtiin were significantly increased by MeJA treatments. The products of some of the GS from endogenous myrosinase hydrolysis [sulforaphane (SF), neoascorbigen (NeoASG), N-methoxyindole-3-carbinol (NI3C), and phenethyl isothiocyanate (PEITC)] were also quantified and found to be significantly correlated with QR. Sulforaphane, the isothiocyanate hydrolysis product of the GS glucoraphanin, was found to be the most potent QR induction agent. Increased sulforaphane formation from the hydrolysis of glucoraphanin was associated with up-regulated gene expression of myrosinase (BoMyo) and the myrosinase enzyme co-factor gene, epithiospecifier modifier1 (BoESM1). This study demonstrates the combined treatment of MeJA and 1-MCP increased QR activity without post-harvest quality loss. PMID:24146962

  13. Role of chlorophyllase in chlorophyll homeostasis and post-harvest breakdown in Piper betle L. leaf.

    Science.gov (United States)

    Gupta, Supriya; Gupta, Sanjay Mohan; Kumar, Nikhil

    2011-10-01

    Piper betle L., a dioecious shade-loving perennial climber is one of the important Pan-Asiatic plants. More than hundred landraces having marked variation in leaf chlorophyll (Chl) content are in cultivation in India. In this study, role of chlorophyllase (Chlase) in Chl homeostasis and post-harvest breakdown was investigated in two contrasting P. betle landraces Kapoori Vellaikodi (KV) with light green and Khasi Shillong (KS) with dark green leaves. The two landraces showed negative correlation between Chl content and Chlase activity in fresh as well as stored leaves. Accumulation of chlorophyllide a (Chlid a) was correlated with the level of Chlase activity, which was higher in KV than KS. The overall response of abscisic acid (ABA) and benzylaminopurine (BAP) was similar in KV and KS, however, the time-course was different. ABA-induced Chl loss was accompanied by rise in Chlase activity in KV and KS and the delay in Chl loss by BAP was accompanied by reduction in Chlase activity. While there were significant differences in Chlase activity in KV and KS, only minor differences were observed in the enzyme properties like pH and temperature optima, Km and Vmax. No landrace-related differences were observed on the effect of metal ions and functional group reagents/amino acid effectors on Chlase activity. These results showed that despite significant differences in Chl content and Chlase activity between landraces KV and KS, the properties of Chlase were similar. The findings show that in P. betle Chlase is involved in Chl homeostasis and also in Chl degradation during post-harvest storage and responds to hormonal regulations. These findings might be useful in predicting the stability of Chl during post-harvest storage and also the shelf-life in other P. betle landraces.

  14. Postharvest behaviour of two Sardinian apple varieties following immersion in heated sodium bicarbonate solution.

    Science.gov (United States)

    Venditti, T; Molinu, M G; Dore, A; Agabbio, M; D'Hallewin, G

    2010-01-01

    'Miali' and 'Caddina' are apple varieties of Sardinian germplasm, mainly produced under sustainable conditions. Fruit is rarely subjected to cold storage and postharvest losses are generally high. In order to prolong the marketing period and contain postharvest decay of these local varieties, we investigated on their storage behaviour and on the efficacy of combined alternative postharvest treatments. Pre-climateric fruit was harvested and immersed for 0 (control), 15, 30, 45 or 60 sec. in water at 20, 50, 55 or 60 degrees C with or without 2% (W/V) NaHCO3 (SBC). Then, fruit was stored for 4 months at 5 degrees C and 90% RH followed by a 6 day simulated marketing period (SMP) at 10 degrees C and 75% RH. Decay was monitored at the end of storage and after the SMP, while appearance and physiological disorders were evaluated after SMP. During storage 56 and 62% of the untreated 'Caddina' and 'Miali' apples rotted, respectively. During the SMP, an additional 3% of 'Caddina' and 5% of 'Miali' was lost. Among the treatments the best decay control, for both varieties, was attained when fruit was immersed in the SBC solution at 55 degrees C for 60 sec. Compared to control, decay was reduced by 91 and 95% for 'Caddina' and 'Miali', respectively. This combination induced some rind damage, mainly on 'Caddina' fruit. Superficial scald was evident on 'Caddina' and scored as medium while, cold storage induced a significant deposition of epicuticular wax in 'Miali' fruit, affecting significantly fruit appearance. A significant reduction of decay was also achieved when fruit was immersed at 60 degrees C for 30 or 45 sec., attaining for 'Caddina' a reduction of 82 and 88% of decay, respectively. Other combinations were lesser effective or produced rind damages and most decay was caused by Penicillium expansum.

  15. Improving environmental performance of post-harvest supply chains of fruits and vegetables in Europe: Potential contribution from ultrasonic humidification

    DEFF Research Database (Denmark)

    Fabbri, Serena; Olsen, Stig Irving; Owsianiak, Mikołaj

    2018-01-01

    Post-harvest losses of fruits and vegetables during refrigerated storage, transportation and retail are an important contributor to total environmental impacts of food supply chains in Europe. Ultrasonic humidification can reduce these post-harvest losses, but it is currently unknown whether...... that humidification may be an attractive technology for making supply chain management more sustainable....... implementing the technology in practice improves the environmental performance of the supply chains. Here, using life cycle assessment we showed that ultrasonic humidification has the potential to reduce environmental impacts, including climate change impacts, of selected fruits and vegetables in Europe by up...

  16. Effects of Lavender Essential Oil and Methyl Salicylate on Gray Mold Control and Postharvest Quality of Strawberry

    Directory of Open Access Journals (Sweden)

    M. Sayyari

    2016-07-01

    Full Text Available Introduction: Strawberry (fragaria×ananassa Duch. fruit characterized by short storage life, often estimated last less than one week even under optimum conditions at 8°C. The loss of fruit quality is often caused by gray mold (Botrytis cinerea that is the most frequent reported postharvest disease in strawberry during storage (6. In recent years, considerable attention has given to elimination of synthetic chemical and fungicides application and development of various alternative strategies for controlling fruit and vegetables diseases (2. One strategy is replacement of natural products with plant origin such as essential oil and methyl salicylate (MeSA. Essential oils are volatile, natural and complex compounds characterized by a strong odor formed by aromatic plants in form of secondary metabolites. In nature, essential similar oils that extract from lavender (Lavandula angustifolia play an important role in protection of the plants against pathogen incidence that can be replaced by synthetic fungicides (1, 4 and 14. MeSA is also a volatile natural compound synthesized from salicylic acid which has an important role in the plant defense-mechanism, as well as plant growth and development (5, 19 and 20. Therefore, the main objective of this research was to study the effects of MeSA and lavender essential oil (LEO on decay control caused by Botrytis cinerea as well as post-harvest quality indices of strawberry fruits during cold storage. Material and Methods: First, antifungal activity was studied by using a contact assay (in vitro, which produces hyphal growth inhibition. Briefly, potato dextrose agar (PDA plates were prepared using 8 cm diameter glass petri dishes and inhibitory percentage was determined. For in-vivo assessment of LEO and MeSA effects on Botrytis-caused fungal disease control, the experiment was conducted as factorial in completely randomized design (CRD with 3 replicates. The treatments were 3 concentration of LEO including

  17. AMPK in Pathogens.

    Science.gov (United States)

    Mesquita, Inês; Moreira, Diana; Sampaio-Marques, Belém; Laforge, Mireille; Cordeiro-da-Silva, Anabela; Ludovico, Paula; Estaquier, Jérôme; Silvestre, Ricardo

    2016-01-01

    During host-pathogen interactions, a complex web of events is crucial for the outcome of infection. Pathogen recognition triggers powerful cellular signaling events that is translated into the induction and maintenance of innate and adaptive host immunity against infection. In opposition, pathogens employ active mechanisms to manipulate host cell regulatory pathways toward their proliferation and survival. Among these, subversion of host cell energy metabolism by pathogens is currently recognized to play an important role in microbial growth and persistence. Extensive studies have documented the role of AMP-activated protein kinase (AMPK) signaling, a central cellular hub involved in the regulation of energy homeostasis, in host-pathogen interactions. Here, we highlight the most recent advances detailing how pathogens hijack cellular metabolism by suppressing or increasing the activity of the host energy sensor AMPK. We also address the role of lower eukaryote AMPK orthologues in the adaptive process to the host microenvironment and their contribution for pathogen survival, differentiation, and growth. Finally, we review the effects of pharmacological or genetic AMPK modulation on pathogen growth and persistence.

  18. Potatoes, pathogens and pests

    NARCIS (Netherlands)

    Lazebnik, Jenny

    2017-01-01

    Currently, fungicides are necessary to protect potato crops against late blight, Phytophthora infestans, one of the world’s most damaging crop pathogens. The introgression of plant resistance genes from wild potato species targeted specifically to the late blight pathogen into

  19. Food-borne pathogens

    International Nuclear Information System (INIS)

    Niemand, J.G.

    1985-01-01

    The Salmonella scare reinforced the importance of never taking chances when it comes to controlling pathogens. The issue has been resolved by radurisation. The article deals with the various pathogens that can effect food and argues the case for radurisation in dealing with them. It also looks at some of the other food products that can be treated using this process

  20. Pathogen inactivation techniques.

    Science.gov (United States)

    Pelletier, J P R; Transue, S; Snyder, E L

    2006-01-01

    The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area

  1. The effect of growth regulators on post-harvest Alchemilla mollis (Bauser Rothm. leaf longevity

    Directory of Open Access Journals (Sweden)

    Janowska Beata

    2016-12-01

    Full Text Available Leaves of Alchemilla mollis (Bauser Rothm. were the subject of the study. The leaves were harvested early in the morning from the department’s ornamental plant collection. Selected leaves were fully-developed and showed no signs of damage or discolouring. Gibberellic acid (GA3, benzyladenine (BA, meta-methoxytopolin (MemT and its riboside (MemTR at concentrations of 25, 50 and 75 mg dm−3 were applied in the form of solutions to four-hour leaf-conditioning in the room at a temperature of 18-20°C. After conditioning, the leaves were placed in distilled water. Leaves put into distilled water immediately after cutting served as the control. The post-harvest longevity of leaves of Alchemilla mollis was 7.2-11.8 days. The conditioning of leaves in gibberellic acid solutions at concentrations of 25-50 mg dm−3, benzyladenine at concentrations of 25 mg dm−3 and meta-methoxytopolin and its riboside at concentrations of 75 mg dm−3 extended the post-harvest longevity of leaves by 10.1-81.9%. The conditioning of leaves in gibberellic acid at a concentration of 50 mg dm−3 inhibited the degradation of chlorophyll, as indicated by the highest SPAD index values.

  2. Effect of plasma activated water on the postharvest quality of button mushrooms, Agaricus bisporus.

    Science.gov (United States)

    Xu, Yingyin; Tian, Ying; Ma, Ruonan; Liu, Qinghong; Zhang, Jue

    2016-04-15

    Non-thermal plasma is a new approach to improving microbiological safety while maintaining the sensory attributes of the treated foods. Recent research has reported that plasma activated water (PAW) can also efficiently inactivate a wide variety of microorganisms. This study invested the effects of plasma-activated water soaking on the postharvest preservation of button mushrooms (Agaricus bisporus) over seven days of storage at 20°C. Plasma activated water reduced the microbial counts by 1.5 log and 0.5 log for bacteria and fungi during storage, respectively. Furthermore, the corresponding physicochemical and biological properties were assessed between plasma activated water soaking groups and control groups. The results for firmness, respiration rate and relative electrical conductivity suggested that plasma activated water soaking can delay mushroom softening. Meanwhile, no significant change was observed in the color, pH, or antioxidant properties of A. bisporus treated with plasma activated water. Thus, plasma activated water soaking is a promising method for postharvest fresh-keeping of A. bisporus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Carbon Monoxide Fumigation Improved the Quality, Nutrients, and Antioxidant Activities of Postharvest Peach

    Science.gov (United States)

    Li, Ying; Pei, Fei

    2014-01-01

    Peaches (Prunus persica cv. Yanhong) were fumigated with carbon monoxide (CO) at 0, 0.5, 5, 10, and 20 μmol/L for 2 hours. The result showed that low concentration CO (0.5–10 μmol/L) might delay the decrease of firmness and titrable acid content, restrain the increase of decay incidence, and postpone the variation of soluble solids content, but treating peaches with high concentration CO (20 μmol/L) demonstrated adverse effects. Further research exhibited that exogenous CO could induce the phenylalnine ammonialyase activity, maintain nutrient contents such as Vitamin C, total flavonoid, and polyphenol, and enhance antioxidant activity according to reducing power and 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl radical scavenging activity. Treating peaches with appropriate concentration CO was beneficial to the quality, nutrients, and antioxidant activity of postharvest peaches during storage time. Therefore, CO fumigation might probably become a novel method to preserve postharvest peach and other fruits in the future. PMID:26904651

  4. Changes in Cuticular Wax Composition of Two Blueberry Cultivars during Fruit Ripening and Postharvest Cold Storage.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Chen, Hangjun; Wu, Weijie; Fang, Xiangjun

    2018-03-21

    Cuticular wax plays an important role for the quality of blueberry fruits. In this study, the cuticular wax composition of two blueberry cultivars, 'Legacy' ( Vaccinium corymbosum) and 'Brightwell' ( Vaccinium ashei), was examined during fruit ripening and postharvest cold storage. The results showed that wax was gradually deposited on the epidermis of blueberry fruits and the content of major wax compounds, except that for diketones, increased significantly during fruit ripening. The total wax content was 2-fold greater in 'Brightwell' blueberries than that in 'Legacy' blueberries during fruit ripening. The total wax content of both cultivars decreased during 30 days of storage at 4 °C, and the variation of cuticular wax composition was cultivar-dependent. The content of diketones decreased significantly in 'Legacy' blueberries, while the content of triterpenoids and aliphatic compounds showed different fold changes in 'Brightwell' blueberries after 30 days of storage at 4 °C. Overall, our study provided a quantitative and qualitative overview of cuticular wax compounds of blueberry fruits during ripening and postharvest cold storage.

  5. Effect of Post-Harvest Treatments on Enzyme Activity and Quality of Cold Stored Ber Fruit

    Directory of Open Access Journals (Sweden)

    Sukhjit K. JAWANDHA

    2012-11-01

    Full Text Available Ber (Zizyphus mauritiana Lamk fruits are perishable in nature and have poor shelf- life. To extend the storage life of ber fruits different post-harvest treatments, like CaCl2 (0.5, 1.0 and 2.0%, Ca(NO32 (0.5, 1.0 and 2.0%, gibberellic acid (GA3 (20, 40 and 60 ppm and Bavistin (0.1% were given to fruits and their effect was studied on the storage life and quality of Umran ber (Zizyphus mauritiana Lamk fruits under cold storage conditions. Fruits of uniform size and colour were harvested, from healthy plants, and subjected to post harvest dip of different chemicals, before packing in CFB boxes and placed in cold storage (3-5C and 85-90% RH They have been evaluated after 10, 20 and 30 days of storage for physiological loss in weight (PLW, firmness, pectin methyl esterase (PME activity and palatability rating. The PLW increased and fruit firmness decreased during storage at each treatment. The sensory rating increased up to 10 days at all treatments, except control but subsequently it decreased during storage. The increase rate in PME activity was faster, up to 10 days, in untreated fruits, while treated fruits showed slower rise in PME activity, up to 20 days with a decline afterwards. It can be concluded that ber fruits can be stored up to 20 days by post-harvest treatment using GA3 at 60 ppm, with acceptable quality.

  6. Quantifying host potentials: indexing postharvest fresh fruits for spotted wing Drosophila, Drosophila suzukii.

    Directory of Open Access Journals (Sweden)

    David E Bellamy

    Full Text Available Novel methodology is presented for indexing the relative potential of hosts to function as resources. A Host Potential Index (HPI was developed as a practical framework to express relative host potential based on combining results from one or more independent studies, such as those examining host selection, utilization, and physiological development of the organism resourcing the host. Several aspects of the HPI are addressed including: 1 model derivation; 2 influence of experimental design on establishing host rankings for a study type (no choice, two-choice, and multiple-choice; and, 3 variable selection and weighting associated with combining multiple studies. To demonstrate application of the HPI, results from the interactions of spotted wing drosophila (SWD, Drosophila suzukii Matsumura (Diptera: Drosophilidae, with seven "reported" hosts (blackberries, blueberries, sweet cherries, table grapes, peaches, raspberries, and strawberries in a postharvest scenario were analyzed. Four aspects of SWD-host interaction were examined: attraction to host volatiles; population-level oviposition performance; individual-level oviposition performance; and key developmental factors. Application of HPI methodology indicated that raspberries ( (meanHPIvaried  = 301.9±8.39; rank 1 of 7 have the greatest potential to serve as a postharvest host for SWD relative to the other fruit hosts, with grapes ( (meanHPIvaried  = 232.4±3.21; rank 7 of 7 having the least potential.

  7. Implications of Postharvest Food Loss/Waste Prevention to Energy and Resources Conservation

    Science.gov (United States)

    Cai, X.; Shafiee-Jood, M.

    2015-12-01

    World's growing demand for food is driven by population and income growth, dietary changes, and the ever-increasing competition between food, feed and bioenergy challenges food security; meanwhile agricultural expansion and intensification threats the environment by the various detrimental impacts. Researchers have attempted to explore strategies to overcome this grand challenge. One of the promising solutions that have attracted considerable attention recently is to increase the efficiency of food supply chain by reducing food loss and waste (FLW). According to recent studies conducted by Food and Agriculture Organization (FAO), United Nation, almost one third of the food produced for human consumption globally is lost or wasted along the food supply chain. This amount of food discarded manifests a missing, yet potential, opportunity to sustainably enhance both food security and environmental sustainability. However, implementing the strategies and technologies for tackling FLW does not come up as an easy solution since it requires economic incentives, benefit and cost analysis, infrastructure development, and appropriate market mechanism. In this presentation I will provide a synthesis of knowledge on the implications of postharvest food loss/waste prevention to energy and resource conservation, environmental protection, as well as food security. I will also discuss how traditional civil and environmental engineering can contribute to the reduction of postharvest food loss, an important issue of sustainable agriculture.

  8. Influence of Cultivar on the Postharvest Hardening of Trifoliate Yam (Dioscorea dumetorum Tubers

    Directory of Open Access Journals (Sweden)

    Christian Siadjeu

    2016-01-01

    Full Text Available The influence of cultivar on the postharvest hardening of Dioscorea dumetorum tubers was assessed. 32 cultivars of D. dumetorum tubers were planted in April 2014, harvested at physiological maturity, and stored under prevailing tropical ambient conditions (19–28°C, 60–85% RH for 0, 5, 14, 21, and 28 days. Samples were evaluated for cooked hardness. Results showed that one cultivar, Ibo sweet 3, was not affected by the hardening phenomenon. The remaining 31 were all subject to the hardening phenomenon at different degree. Cooked hardness increased more rapidly in cultivars with many roots on the tuber surface compared to cultivars with few roots on the tuber surface. When both the characteristics flesh colour and number of roots on tuber surface were associated, cooked hardness in cultivars with yellow flesh and many roots increased more rapidly than in cultivars with white flesh and many roots, whereas cooked hardness in cultivars with yellow flesh and few roots increased more slowly than in cultivars with white flesh and few roots. Accessions collected in high altitude increased more rapidly compared to accessions collected in low altitude. The cultivar Ibo sweet 3 identified in this study could provide important information for breeding program of D. dumetorum against postharvest hardening phenomenon.

  9. Ionizing radiation treatment to improve postharvest life and maintain quality of fresh guava fruit

    International Nuclear Information System (INIS)

    Singh, S.P.; Pal, R.K.

    2009-01-01

    We investigated the potential of ionizing radiation for improving physiological responses, quality, and storage time of fresh guava fruit. Ionizing radiation treatment suppressed the respiration and ethylene production rates and thus retarded the process of fruit ripening during storage. Irradiation treatment also retarded the physical and biochemical changes associated with ripening such as firmness, titratable acidity, soluble solids content, and vitamin C during storage, but for doses higher than 0.25 kGy the vitamin C content decreased. The positive effects of ionizing radiation treatment on delayed fruit ripening and other quality attributes diminished during 22 days of storage at 10 deg. C. Thus, a combination of ionizing radiation with low-temperature storage (10 deg. C) did not have much synergistic effect on storage life and quality of guava fruit. In conclusion, ionizing radiation treatment of guava fruit with 0.25 kGy dose increased the postharvest life by 3-4 days, maintained fruit quality, and reduced the decay incidence. The optimal dose (0.25 kGy) for postharvest life extension of guava fruit may be exploited to provide phytosanitary security against many insect pests including fruit flies

  10. Hydrogen sulfide extends the postharvest life and enhances antioxidant activity of kiwifruit during storage.

    Science.gov (United States)

    Zhu, Liqin; Wang, Wei; Shi, Jingying; Zhang, Wei; Shen, Yonggen; Du, Huaying; Wu, Shaofu

    2014-10-01

    Exogenous hydrogen sulfide (H₂S) treatment can prolong the postharvest life of cut flowers and strawberries. Little work has been done to explore the effects of H₂S on respiratory climacteric fruits such as kiwifruits during storage. Therefore the aim of the present study was to evaluate the effects of H₂S treatment at concentrations of 15–1000 µmol L⁻¹ on the postharvest life of kiwifruit during 25 °C storage and the role of H₂S in regulating the antioxidant defensive system of kiwifruit. Treatments with 45 and 90 µmol L⁻¹ H₂S significantly inhibited the increase in soluble sugar content and the decrease in vitamin C (Vit C), chlorophyll content and firmness, inhibited ethylene production and both superoxide production rate (O(·2)⁻) and hydrogen peroxide content. Kiwifruits with 45 and 90 µmol L⁻¹ H₂S exhibited significantly higher activities of superoxide dismutase, catalase and peroxidase. Treatment with 180 µmol L⁻¹ H₂S promoted the ripening of kiwifruits. Treatments with 45 and 90 µmol L⁻¹ H₂S could delay the maturation and senescence of kiwifruits and maintain higher titratable acid (TA) and Vit C during eating-ripe storage by inhibiting ethylene production, improving protective enzyme activities and decreasing the accumulation of reactive oxygen species to protect the cell membrane during storage. © 2014 Society of Chemical Industry.

  11. Postharvest Processing and Benefits of Black Pepper, Coriander, Cinnamon, Fenugreek, and Turmeric Spices.

    Science.gov (United States)

    Balasubramanian, S; Roselin, P; Singh, K K; Zachariah, John; Saxena, S N

    2016-07-26

    Spices are prime source for flavor, aroma, and taste in cuisines and play an active role as medicines due to their high antioxidant properties. As medicine or food, the importance of spices cannot be overemphasized. The medicinal values of spices are very well established in treating various ailments like cancer, fever, malaria, stomach offset, nausea, and many more. A spice may be available in several forms: fresh, whole dried, or pre-ground dried which requires further processing to be utilized in the form of value-added product. This review paper deals with the cultivation, postharvesting, chemical composition, uses, health, and medicinal benefits of the selected spice viz., black pepper, coriander, cinnamon, fenugreek, turmeric, and technological advances in processing of spices viz., super critical fluid extraction, cryogenic grinding, and microencapsulation etc. This paper also focuses on issues related to utilization of spices toward its high end-product development and characterization in pharmaceuticals and other medicinal purposes. The availability of different spices and their varietal differences and location have their pertinent characters, which are much demanding to refine postharvest and processing to assure its quality in the international market.

  12. Preharvest methyl jasmonate and postharvest UVC treatments: increasing stilbenes in wine.

    Science.gov (United States)

    Fernández-Marín, María Isabel; Puertas, Belén; Guerrero, Raúl F; García-Parrilla, María Carmen; Cantos-Villar, Emma

    2014-03-01

    Stilbene-enriched wine is considered to be an interesting new food product with added value due to its potential health-promoting properties. Stilbene concentration in grape is highly variable and rather scarce. However, it can be increased by stress treatments. For this reason, numerous pre- and postharvest grape treatments, and some combinations of them, have been tested to maximize stilbene content in grapes. In the present manuscript, Syrah grapes were treated with (i) methyl jasmonate (MEJA), (ii) ultraviolet light (UVC), and (iii) methyl jasmonate and ultraviolet light (MEJA-UVC) and compared with untreated grapes. Afterward, winemaking was developed. Wine achieved by combination of both treatments (MEJA-UVC) contained significantly higher stilbene concentration (trans-resveratrol and piceatannol) than its respective control (2.5-fold). Wine quality was improved in color-related parameters (color intensity, L*, a*, b*, ΔE*, anthocyanins, and tannin). Moreover, MEJA-UVC wines obtained the highest score in sensorial analysis. To the best of our knowledge, this is the first time that pre- and postharvest treatments are combined to increase stilbenes in wine. The effect of treatment combination (methyl jasmonate and UVC light) on grape and wine was evaluated. Our results highlight the positive effect of the treatments in stilbene content, color parameters, and sensorial analysis. Moreover, added-value by-products were achieved. © 2014 Institute of Food Technologists®

  13. Responses of Phospholipase D and Antioxidant System to Mechanical Wounding in Postharvest Banana Fruits

    Directory of Open Access Journals (Sweden)

    Li Li

    2017-01-01

    Full Text Available Banana fruits are susceptible to mechanical damage. The present study was to investigate the responses of phospholipase D (PLD and antioxidant system to mechanical wounding in postharvest banana fruits. During 16 d storage at 25°C and 90% relative humidity, PLD activity in wounded fruits was significantly higher than that in control (without artificial wounding fruits. The higher value of PLD mRNA was found in wounded fruits than in control. PLD mRNA expression reached the highest peak on day 4 in both groups, but it was 2.67 times in wounded fruits compared to control at that time, indicating that PLD gene expression was activated in response to wounding stress. In response to wounding stress, the higher lipoxygenase (LOX activity was observed and malondialdehyde (MDA production was accelerated. The activities of antioxidant enzymes such as superoxide dismutase (SOD, catalase (CAT, peroxidase (POD, and ascorbate peroxidase (APX in wounded fruits were significantly higher than those in control. The concentrations of reactive oxygen species (ROS such as superoxide anion (O2•- and hydrogen peroxide (H2O2 in fruits increased under mechanical wounding. The above results provided a basis for further investigating the mechanism of postharvest banana fruits adapting to environmental stress.

  14. Storage and methyl jasmonate in postharvest conservation of roses cv. Avalanche

    Directory of Open Access Journals (Sweden)

    Elka Fabiana Aparecida Almeida

    2017-07-01

    Full Text Available The use of methyl jasmonate has demonstrated its efficiency to extend the vase life of cut flowers. The objective of this study was to evaluate the effect of methyl jasmonate associated with storage at low temperatures on the postharvest quality of Rosa cv. Avalanche stems. The treatments consisted of 125, 250, 500 and 1000 μM of methyl jasmonate, besides the control with distilled water. The flower buds were sprayed with 4 mL of the solution, according to the treatments, and then kept in a cold chamber (1 °C for periods of 2 and 6 days. Subsequently, the stems were taken to the postharvest laboratory at a temperature of 16 °C. Better quality, higher fresh weight and water absorption were observed in flower stems stored for 2 days. The application of methyl jasmonate caused less turgescence and greater darkening of roses. It was possible to conclude that two days is the best storage time at 1 °C and the use of methyl jasmonate does not maintain the quality of roses cv. Avalanche after harvest.

  15. Adoption of On-farm and Post-harvest Rice Quality Enhancing Technologies in Nigeria

    Directory of Open Access Journals (Sweden)

    Tiamiyu, SA.

    2014-01-01

    Full Text Available This paper examines the rate and determinants of adoption of improved rice quality enhancing technologies among a randomly selected sample of 150 farmers and 18 rice processors from six rice producing areas of Niger State. Data were collected through interview schedule using questionnaires. Descriptive statistics and regression model were adopted to analyze data. Results show that adoption of quality enhancing technologies was low among the selected sample of these rice value chain actors. The adoption indices of on-farm and post-harvest quality enhancing practices were 0.46 and 0.37 respectively. Some socioeconomic attributes including: Age, level of education, contact with extension, access to credit and level of commercialization were statistically significant determining factors (P≤0.05 influencing adoption at farm level, while post-harvest technology adoption was determined by level of education, access to credit and membership of cooperatives. Promotion of quality enhanced technologies among these actors in the rice value chain is recommended.

  16. The diversity of postharvest losses in cassava value chains in selected developing countries

    Directory of Open Access Journals (Sweden)

    Diego Naziri

    2014-12-01

    Full Text Available The extent of physical and economic postharvest losses at different stages of cassava value chains has been estimated in four countries that differ considerably in the way cassava is cultivated, processed and consumed and in the relationships and linkages among the value chain actors. Ghana incurs by far the highest losses because a high proportion of roots reach the consumers in the fresh form. Most losses occur at the last stage of the value chain. In Nigeria and Vietnam processors incur most of the losses while in Thailand most losses occur during harvesting. Poorer countries incur higher losses despite their capacity to absorb sub-standard products (therefore transforming part of the physical losses into economic losses and less strict buyer standards. In monetary terms the impact of losses is particularly severe in Ghana and estimated at about half a billion US dollar per annum while in the other countries it is at the most about USD 50 million. This comparison shows that there are no “one-size-fits-all" solutions for addressing postharvest losses but rather these must be tailor-made to the specific characteristics of the different value chains.

  17. Bioactivity of essential oils in phytopathogenic and post-harvest fungi control.

    Science.gov (United States)

    Santamarina, M P; Ibáñez, M D; Marqués, M; Roselló, J; Giménez, S; Blázquez, M A

    2017-11-01

    Commercial thyme and lavender essential oils were analysed by GC/MS. Sixty-six compounds accounting for 98.6-99.6% of total essential oil were identified. Thymol (52.14 ± 0.21%), followed by p-cymene (32.24 ± 0.16%), carvacrol (3.71 ± 0.01%) and γ-terpinene (3.34 ± 0.02%), were the main compounds in thyme essential oil, while large amounts of oxygenated monoterpenes linalool acetate (37.07 ± 0.24%) and linalool (30.16 ± 0.06%) were found in lavender one. In vitro antifungal activity of the essential oils was evaluated at 200 and 300 μg/mL against 10 phytopathogenic and post-harvest fungi, which significantly affect agriculture. Micelial growth inhibition was calculated for each tested fungus and dose. Thyme essential oil showed satisfactory results with 90-100% growth inhibition in almost all the assayed fungi at 300 μg/mL, while lavender essential oil showed no noteworthy inhibition data at either dose, and its growth was even enhanced. Thyme essential oil represents a natural alternative to control harvest and post-harvest fungi, and to extend the shelf-life of agriculture products.

  18. Disposable gendine antimicrobial gloves for preventing transmission of pathogens in health care settings.

    Science.gov (United States)

    Reitzel, Ruth; Rosenblatt, Joel; Jiang, Ying; Hachem, Ray; Raad, Issam

    2014-01-01

    Transmission of organisms by contact of gloves with surfaces following contact with a pathogen source has been recognized as an important vector for pathogenesis of health care-associated infections. In these cases, the gloves protect the wearer from contact with the pathogenic organisms; however, this personal protection can facilitate the wearer unwittingly becoming a carrier of the pathogens from one location to another. A novel gendine (combination of chlorhexidine and gentian violet) antiseptic coating for the external surface of the glove was developed as a potential intervention to prevent this mode of transmission. We characterized the ability of the coating to rapidly kill bacterial and fungal pathogens within 1 minute of contact with the glove surface. The International Organization of Standardization 22196 concentrated inoculum contact testing methodology was followed. The gendine-coated gloves were able to fully eradicate multidrug-resistant organisms included methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterocci, multidrug-resistant Pseudomonas aeruginosa, and Klebsiella pneumoniae carbapenemase producing. In addition, Candida albicans, Candida glabarata, and 2 pathogenic Escherichia coli strains commonly associated with invasive gastroenteritis were also fully eradicated within 1 minute of contact. The gendine coating did not adversely impact the finish or integrity of the disposable gloves. The highly efficacious gendine-coated antimicrobial gloves potentially provide an additional means of protection against horizontal transmission of common pathogens in a hospital setting. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  19. Processes for managing pathogens.

    Science.gov (United States)

    Godfree, Alan; Farrell, Joseph

    2005-01-01

    Wastewater contains human, animal, and plant pathogens capable of causing viral, bacterial, or parasitic infections. There are several routes whereby sewage pathogens may affect human health, including direct contact, contamination of food crops, zoonoses, and vectors. The range and numbers of pathogens in municipal wastewater vary with the level of endemic disease in the community, discharges from commercial activities, and seasonal factors. Regulations to control pathogen risk in the United States and Europe arising from land application of biosolids are based on the concept of multiple barriers to the prevention of transmission. The barriers are (i) treatment to reduce pathogen content and vector attraction, (ii) restrictions on crops grown on land to which biosolids have been applied, and (iii) minimum intervals following application and grazing or harvesting. Wastewater treatment reduces number of pathogens in the wastewater by concentrating them with the solids in the sludge. Although some treatment processes are designed specifically to inactivate pathogens, many are not, and the actual mechanisms of microbial inactivation are not fully understood for all processes. Vector attraction is reduced by stabilization (reduction of readily biodegradable material) and/or incorporation immediately following application. Concerns about health risks have renewed interest in the effects of treatment (on pathogens) and advanced treatment methods, and work performed in the United States suggests that Class A pathogen reduction can be achieved less expensively than previously thought. Effective pathogen risk management requires control to the complete chain of sludge treatment, biosolids handling and application, and post-application activities. This may be achieved by adherence to quality management systems based on hazard analysis critical control point (HACCP) principles.

  20. Improved microbial conversion of de-oiled Jatropha waste into biohydrogen via inoculum pretreatment: process optimization by experimental design approach

    Directory of Open Access Journals (Sweden)

    Gopalakrishnan Kumar

    2015-03-01

    Full Text Available In this study various pretreatment methods of sewage sludge inoculum and the statistical process optimization of de-oiled jatropha waste have been reported. Peak hydrogen production rate (HPR and hydrogen yield (HY of 0.36 L H2/L-d and 20 mL H2/g Volatile Solid (VS were obtained when heat shock pretreatment (95 oC, 30 min was employed. Afterwards, an experimental design was applied to find the optimal conditions for H2 production using heat-pretreated seed culture. The optimal substrate concentration, pH and temperature were determined by using response surface methodology as 205 g/L, 6.53 and 55.1 oC, respectively. Under these circumstances, the highest HPR of 1.36 L H2/L-d was predicted. Verification tests proved the reliability of the statistical approach. As a result of the heat pretreatment and fermentation optimization, a significant (~ 4 folds increase in HPR was achieved. PCR-DGGE results revealed that Clostridium sp. were majorly present under the optimal conditions.

  1. Microbial monitoring of ammonia removal in a UASB reactor treating pre-digested chicken manure with anaerobic granular inoculum.

    Science.gov (United States)

    Yangin-Gomec, Cigdem; Pekyavas, Goksen; Sapmaz, Tugba; Aydin, Sevcan; Ince, Bahar; Akyol, Çağrı; Ince, Orhan

    2017-10-01

    Performance and microbial community dynamics in an upflow anaerobic sludge bed (UASB) reactor coupled with anaerobic ammonium oxidizing (Anammox) treating diluted chicken manure digestate (Total ammonia nitrogen; TAN=123±10mg/L) were investigated for a 120-d operating period in the presence of anaerobic granular inoculum. Maximum TAN removal efficiency reached to above 80% with as low as 20mg/L TAN concentrations in the effluent. Moreover, total COD (tCOD) with 807±215mg/L in the influent was removed by 60-80%. High-throughput sequencing revealed that Proteobacteria, Actinobacteria, and Firmicutes were dominant phyla followed by Euryarchaeota and Bacteroidetes. The relative abundance of Planctomycetes significantly increased from 4% to 8-9% during the late days of the operation with decreased tCOD concentration, which indicated a more optimum condition to favor ammonia removal through anammox route. There was also significant association between the hzsA gene and ammonia removal in the UASB reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. High efficient ethanol and VFAs production from gas fermentation: effect of acetate, gas and inoculum microbial composition

    DEFF Research Database (Denmark)

    El-Gammal, Maie; Abou-Shanab, Reda; Angelidaki, Irini

    2017-01-01

    In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas fermenta......In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas...... fatty acids and ethanol was achieved by the pure culture (Clostridium ragsdalei). Depending on the headspace gas composition, VFA concentrations were up to 300% higher after fermentation with Clostridium ragsdalei compared to fermentation with mixed culture. The preferred gas composition with respect...... to highest VFA concentration was pure CO (100%) regardless of microbial composition of the inoculum and media composition. The addition of acetate had a negative impact on the VFA formation which was depending on the initial gas composition in head space....

  3. Effects of inoculum to substrate ratio and co-digestion with bagasse on biogas production of fish waste.

    Science.gov (United States)

    Xu, Jie; Mustafa, Ahmed M; Sheng, Kuichuan

    2017-10-01

    To overcome the biogas inhibition in anaerobic digestion of fish waste (FW), effects of inoculum to substrate ratio (I/S, based on VS) and co-digestion with bagasse on biogas production of FW were studied in batch reactors. I/S value was from 0.95 to 2.55, bagasse content in co-digestion (based on VS) was 25%, 50% and 75%. The highest biogas yield (433.4 mL/gVS) with 73.34% methane content was obtained at an I/S value of 2.19 in mono-digestion of FW; the biogas production was inhibited and the methane content was below 70% when I/S was below 1.5. Co-digestion of FW and bagasse could improve the stability and biogas potential, also reducing the time required to obtain 70% of the total biogas production, although the total biogas yield and methane content decreased with the increase in bagasse content in co-digestion. Biogas yield of 409.5 mL/gVS was obtained in co-digestion of 75% FW and 25% bagasse; simultaneously 78.46% of the total biogas production was achieved after 10 days of digestion.

  4. High efficiency bio-hydrogen production from glucose revealed in an inoculum of heat-pretreated landfill leachate sludge

    International Nuclear Information System (INIS)

    Wong, Y.M.; Juan, J.C.; Ting, Adeline; Wu, T.Y.

    2014-01-01

    Bio-hydrogen is a promising sustainable energy to replace fossil fuels. This study investigated bio-H 2 production from the inoculum of heat-pretreated landfill leachate sludge using glucose as model substrate. The seed sludge pretreated at 65 °C showed the highest amount of H 2 at the optimum condition of pH 6 and 37 °C. The maximum H 2 yield estimated by the modified Gompertz model was 6.43 mol H 2 /mol glucose. The high efficient of H 2 production is thermodynamically feasible with the Gibbs free energy of −34 kJ/mol. This study reveals that pretreated landfill leachate sludge has considerable potential for H 2 production. - Highlights: • Heat retreated landfill leachate sludge revealed high efficient H 2 production. • High efficient H 2 yield, 6.4 mol H 2 /mol glucose. • The synergisms between H 2 -producing bacteria may responsible for the high H 2 yield. • High H 2 yield is thermodynamically feasible with Gibbs free energy of −34 kJ/mol

  5. Optimization of solid content, carbon/nitrogen ratio and food/inoculum ratio for biogas production from food waste.

    Science.gov (United States)

    Dadaser-Celik, Filiz; Azgin, Sukru Taner; Yildiz, Yalcin Sevki

    2016-12-01

    Biogas production from food waste has been used as an efficient waste treatment option for years. The methane yields from decomposition of waste are, however, highly variable under different operating conditions. In this study, a statistical experimental design method (Taguchi OA 9 ) was implemented to investigate the effects of simultaneous variations of three parameters on methane production. The parameters investigated were solid content (SC), carbon/nitrogen ratio (C/N) and food/inoculum ratio (F/I). Two sets of experiments were conducted with nine anaerobic reactors operating under different conditions. Optimum conditions were determined using statistical analysis, such as analysis of variance (ANOVA). A confirmation experiment was carried out at optimum conditions to investigate the validity of the results. Statistical analysis showed that SC was the most important parameter for methane production with a 45% contribution, followed by F/I ratio with a 35% contribution. The optimum methane yield of 151 l kg -1 volatile solids (VS) was achieved after 24 days of digestion when SC was 4%, C/N was 28 and F/I were 0.3. The confirmation experiment provided a methane yield of 167 l kg -1 VS after 24 days. The analysis showed biogas production from food waste may be increased by optimization of operating conditions. © The Author(s) 2016.

  6. Influence of feed/inoculum ratios and waste cooking oil content on the mesophilic anaerobic digestion of food waste.

    Science.gov (United States)

    Li, Yangyang; Jin, Yiying; Borrion, Aiduan; Li, Jinhui

    2018-03-01

    Information on the anaerobic digestion (AD) of food waste (FW) with different waste cooking oil contents is limited in terms of the effect of the initial substrate concentrations. In this work, batch tests were performed to evaluate the combined effects of waste cooking oil content (33-53%) and feed/inoculum (F/I) ratios (0.5-1.2) on biogas/methane yield, process stability parameters and organics reduction during the FW AD. Both waste cooking oil and the inoculation ratios were found to affect digestion parameters during the AD process start-up and the F/I ratio was the predominant factor affecting AD after the start-up phase. The possible inhibition due to acidification caused by volatile fatty acids accumulation, low pH values and long-chain fatty acids was reversible. The characteristics of the final digestate indicated a stable anaerobic system, whereas samples with F/I ratios ranging from 0.8 to 1.2 display higher propionic and valeric acid contents and high amounts of total ammonia nitrogen and free ammonia nitrogen. Overall, F/I ratios higher than 0.70 caused inhibition and resulted in low biogas/methane yields from the FW. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Alcohol-to-acid ratio and substrate concentration affect product structure in chain elongation reactions initiated by unacclimatized inoculum.

    Science.gov (United States)

    Liu, Yuhao; Lü, Fan; Shao, Liming; He, Pinjing

    2016-10-01

    The objective of the study was to investigate whether the ratio of ethanol to acetate affects yield and product structure in chain elongation initiated by unacclimatized mixed cultures. The effect of varying the substrate concentration, while maintaining the same ratio of alcohol to acid, was also investigated. With a high substrate concentration, an alcohol to acid ratio >2:1 provided sufficient electron donor capacity for the chain elongation reaction. With an ethanol to acetate ratio of 3:1 (300mM total carbon), the highest n-caproate concentration (3033±98mg/L) was achieved during the stable phase of the reaction. A lower substrate concentration (150mM total carbon) gave a lower yield of products and led to reduced carbon transformation efficiency compared with other reaction conditions. The use of unacclimatized inoculum in chain elongation can produce significant amounts of odd-carbon-number carboxylates as a result of protein hydrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Implication of Abscisic Acid on Ripening and Quality in Sweet Cherries: Differential Effects during Pre- and Post-harvest

    Science.gov (United States)

    Tijero, Verónica; Teribia, Natalia; Muñoz, Paula; Munné-Bosch, Sergi

    2016-01-01

    Sweet cherry, a non-climacteric fruit, is usually cold-stored during post-harvest to prevent over-ripening. The aim of the study was to evaluate the role of abscisic acid (ABA) on fruit growth and ripening of this fruit, considering as well its putative implication in over-ripening and effects on quality. We measured the endogenous concentrations of ABA during the ripening of sweet cherries (Prunus avium L. var. Prime Giant) collected from orchard trees and in cherries exposed to 4°C and 23°C during 10 days of post-harvest. Furthermore, we examined to what extent endogenous ABA concentrations were related to quality parameters, such as fruit biomass, anthocyanin accumulation and levels of vitamins C and E. Endogenous concentrations of ABA in fruits increased progressively during fruit growth and ripening on the tree, to decrease later during post-harvest at 23°C. Cold treatment, however, increased ABA levels and led to an inhibition of over-ripening. Furthermore, ABA levels positively correlated with anthocyanin and vitamin E levels during pre-harvest, but not during post-harvest. We conclude that ABA plays a major role in sweet cherry development, stimulating its ripening process and positively influencing quality parameters during pre-harvest. The possible influence of ABA preventing over-ripening in cold-stored sweet cherries is also discussed. PMID:27200070

  9. Effect of defoliation prior to a frost on postharvest respiration rate, extractable sucrose, and invert sugar concentration of sugarbeet

    Science.gov (United States)

    This study investigated the effect of defoliation prior to a frost on postharvest storage properties of sugarbeet (Beta vulgaris L.). Roots of plants with canopies intact until harvest were compared to roots of plants that had been defoliated prior to a frost on multiple harvest dates following a da...

  10. Post-harvest quality model of pineapple guava fruit according to storage and weather conditions of cultivation

    Directory of Open Access Journals (Sweden)

    Alfonso Parra-Coronado

    Full Text Available ABSTRACT The post-harvest quality of pineapple guava fruit is determined by the storage and prevailing weather conditions during growth and development. This study proposes a model for post-harvest fruit quality according to the storage and weather conditions in the pineapple guava growing region. Physiologically ripe fruit were collected during two harvests from two locations within the Department of Cundinamarca (Colombia: Tenjo and San Francisco de Sales. The fruits were stored at 18 ± 1 °C (76 ± 5% relative humidity (RH, over 11 days and at 5 ± 1 °C (87 ± 5% RH, over 31 days, and the quality attributes were evaluated every two days. Models of the most significant physio-chemical quality characteristics of the post-harvest fruit were developed by using the Excel® Solver tool for all data obtained in the two crop periods. The results showed that storage and prevailing weather conditions, which differed according to the altitude of the growing site, had considerable impacts on the physio-chemical characteristics of the fruit throughout the post-harvest ripening process.

  11. Metropolitan food supply : case study Cairo : a quick scan study to enhance fresh food supply and minimize postharvest losses

    NARCIS (Netherlands)

    Broek, van den W.H.A.M.; Boerrigter, H.A.M.

    2014-01-01

    To investigate options for “Metropolitan food production systems” in Egypt and specifically in the Cairo region, a ‘cold chain quick scan’ is conducted by Wageningen UR post-harvest specialists. The study comprehends a quick scan for market demand, market willingness and a search for trend

  12. Opportunities and Best Practices to Support Sustainable Production for Small Growers and Post-Harvest Processors in Southern California

    Science.gov (United States)

    Fissore, Cinzia; Duran, Daniel F.; Russell, Robert

    2015-01-01

    This article describes current practices and needs associated with water and gas conservation among Southern California greenhouse growers, Post-Harvest Processors (PHPs), and agricultural associations. Two communication forums were held with the goal of educating the local gas company and small growers and PHPs on the most compelling needs and…

  13. Post-harvesting silvicultural treatments in logging gaps: A comparison between enrichment planting and tending of natural regeneration

    NARCIS (Netherlands)

    Schwartz, G.; Lopes, J.C.A.; Mohren, G.M.J.; Peña-Claros, M.

    2013-01-01

    Despite greatly improved forest management in recent decades, long-term assessments show that if current harvesting volumes and cutting cycles are maintained, future volume yields of commercial species will decrease. A possible solution is to apply post-harvesting silvicultural treatments to

  14. Mucor rot - An emerging postharvest disease of mandarin fruit caused by Mucor piriformis and other Mucor spp. in California

    Science.gov (United States)

    In recent years, an emerging, undescribed postharvest fruit rot disease was observed on mandarin fruit after extended storage in California. We collected decayed mandarin fruit from three citrus packinghouses in the Central Valley of California in 2015 and identified this disease as Mucor rot caused...

  15. Postharvest and sensory evaluation of selected ‘Hass’-‘Bacon’ avocado hybrids grown in East-Central Florida

    Science.gov (United States)

    Avocado (Persea americana Mill.) is a high-value fruit that continues to increase in consumer demand. A population of ‘Hass’-‘Bacon’ hybrids was planted at USDA-ARS, Fort Pierce as part of a study to find selections with good horticultural and postharvest quality traits for Florida. Extensive pheno...

  16. IMPROVEMENT OF MANGOSTEEN FARMING AND POSTHARVEST HANDLING STRATEGIES BASED ON GLOBAL GAP STANDARD AT KIARA PEDES, PURWAKARTA DISTRICT

    Directory of Open Access Journals (Sweden)

    Nanda Erlangga

    2012-09-01

    Full Text Available The objectives of this research were (1 to determine the value chain of mangosteen at Kiara Pedes Sub district, Purwakarta District, (2 to identify the gap between actual condition at Kiara Pedes and Global GAP standard, (3 to identify internal and external factors that can affect the implementation strategy of Global GAP standards, and (4 to develop alternative strategies that can be applied to improve the system of mangosteen cultivation and post harvest handling based on Global GAP standards. The analytical tools being used in this study were value chain analysis, gap analysis, internal and external factor evaluation (IFE, EFE, IE matrix, SWOT analysis, and quantitative strategic planning matrix (QSPM. Identified primary actors in mangosteen value chain were farmers, middlemen, suppliers, exporters, and local and overseas retailers. Based on IE Matrix and SWOT analysis, the strategies to implement Global GAP standards were (a to increase mangosteen productivity and improve its quality by using developed cultivation and postharvest technology, (b to increase productivity, and improve quality and transportation network in accordance with Global GAP standard, (c to improve clean water and post-harvest infrastructure through cooperation with exporters and financial institutions, and (d to improve warehouse and supporting facilities such as packaging and sanitation according to the Global GAP standard for minimizing the environmental constraints. The most priority strategies from the QSPM analysis were improving clean water and post-harvest infrastructure through cooperation with exporters and financial institutions, followed by using the developed cultivation and postharvest technology to increase mangosteen productivity and improve its quality.Keywords: Mangosteen, Global GAP Standard, Value Chain, Improvement Strategies, Farming and Postharvest Handling Practices

  17. Induction of sporulation and the influence of time, temperature, and inoculum size on growth in two species of aquatic fungi (Saprolegniales)

    Science.gov (United States)

    Bailey, T.A.; Bradford, K.; Bland, C.E.

    1990-01-01

    Because the infective stage of most mycoses of aquatic organisms is the zoospore, we attempted to establish optimum conditions under which zoospores could be produced for use in antifungal testing. Optimum sporulation time, incubation time, inoculum size, and growth temperature were determined for each oftwo saprolegniaceous fungi, Achlya flagellata Coker and Saprolegnia hypogyna (Pringsheim) de Bary. Both species produced the largest number of zoospores after 18 hours (51.7 spores/ml for A. jlagellata and 848.0 spores/ml for S. hypogyna), and yielded maximum growth after 48 hours at 22 'C. The recommended test inoculum size for S. hypogyna (5,600 spores/ml was nearly three times that for A. flagellata (2,000 spores/ml),

  18. Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation

    DEFF Research Database (Denmark)

    Birch, Heidi; Hammershøj, Rikke Høst; Comber, Mike

    2017-01-01

    Biodegradation is a dominant removal process for many organic pollutants, and biodegradation tests serve as tools for assessing their environmental fate within regulatory risk assessment. In simulation tests, the inoculum is not standardized, varying in microbial quantity and quality, thereby...... potentially impacting the observed biodegradation kinetics. In this study we investigated the effect of inoculum origin on the biodegradation kinetics of hydrocarbons for five inocula from surface waters varying in urbanization and thus expected pre-exposure to petroleum hydrocarbons. A new biodegradation...... method for testing mixtures of hydrophobic chemicals at trace concentrations was demonstrated: Aqueous solutions containing 9 hydrocarbons were generated by passive dosing and diluted with surface water resulting in test systems containing native microorganisms exposed to test substances at ng...

  19. Effect of soil solarization on soil-borne pathogens

    International Nuclear Information System (INIS)

    Sobh, Hana

    1995-01-01

    Author.Soil solarization was conducted at three locations on the Lebanese coast. Maximum soil temperatures recorded were 53 and 48 celsius degrees at Jiyeh, 48.9, 46 and 43 celsius degrees at Naameh and 48, 45 and 43.5 celsius degrees at Khaldeh at 5, 15 and 25cm soil depths respectively. Mean soil temperatures recorded at 3pm were at Jiyeh 51.6, 47 and 46 celsius degrees compared to Naameh 47, 45 and 41 celsius degrees and Khaldeh 44, 42 and 41 celsius degrees at 5, 15 and 25 cm respectively. The mean temperature in solarized soils were 7.3 to 15 celsius degrees higher than those of the nonsolarized soils indicating a sustained increase of soil temperature in the solarized soils. The effect of soil solarization on artificially introduced fungal pathogens in the soil at Khaldeh, resulted in complete destruction of sclerotia of Sclerotinia spp. at three depths studied. However, with respect to the two other pathogens tested, solarization resulted in reduction of the viability of microsclerotia of Verticillium spp. by 99-79% and of Fusarium oxysporum f. sp. melonis inoculum by 88-54% at 5 and 15 cm respectively, but only by 45% and 14% reduction at 25 cm. This level of control is significant when it is compared to the percentage of control where the level of reduction of inoculum viability did not exceed 10% at any soil depth. As there were contradicting reports in the literature on nematodes, two field trials in greenhouses were conducted to study the possibility of integrating 2 methods for management on nematodes. Soil solarization alone or in combination with biological control of nematodes using Arthrobotrys spp. and Dactyl ella brocophaga to control the root-knot nematodes on two crops, tomato at Naameh and cucumber at Jiyeh were compared to Methyl Bromide treatment. It was evident that, even on a very susceptible crop like cucumber, the integration of biological control and soil solarization gave a good level of control similar to methyl bromide. Neither root

  20. Using lytic bacteriophages to eliminate or significantly reduce contamination of food by foodborne bacterial pathogens.

    Science.gov (United States)

    Sulakvelidze, Alexander

    2013-10-01

    Bacteriophages (also called 'phages') are viruses that kill bacteria. They are arguably the oldest (3 billion years old, by some estimates) and most ubiquitous (total number estimated to be 10(30) -10(32) ) known organisms on Earth. Phages play a key role in maintaining microbial balance in every ecosystem where bacteria exist, and they are part of the normal microflora of all fresh, unprocessed foods. Interest in various practical applications of bacteriophages has been gaining momentum recently, with perhaps the most attention focused on using them to improve food safety. That approach, called 'phage biocontrol', typically includes three main types of applications: (i) using phages to treat domesticated livestock in order to reduce their intestinal colonization with, and shedding of, specific bacterial pathogens; (ii) treatments for decontaminating inanimate surfaces in food-processing facilities and other food establishments, so that foods processed on those surfaces are not cross-contaminated with the targeted pathogens; and (iii) post-harvest treatments involving direct applications of phages onto the harvested foods. This mini-review primarily focuses on the last type of intervention, which has been gaining the most momentum recently. Indeed, the results of recent studies dealing with improving food safety, and several recent regulatory approvals of various commercial phage preparations developed for post-harvest food safety applications, strongly support the idea that lytic phages may provide a safe, environmentally-friendly, and effective approach for significantly reducing contamination of various foods with foodborne bacterial pathogens. However, some important technical and nontechnical problems may need to be addressed before phage biocontrol protocols can become an integral part of routine food safety intervention strategies implemented by food industries in the USA. © 2013 Society of Chemical Industry.

  1. Effect of inoculum and molasses concentration as supplement to vinasse of distillery for the production of biomass of native Candida utilis

    Directory of Open Access Journals (Sweden)

    Lady Cajo

    2011-06-01

    Full Text Available Vinasse is a residue of alcohol distilleries, rich in mineral salts and organic matter, whose use is limited and finally it is poured to the sewage system, causing pollution, nevertheless, can constitute a substrate for the production of biomass yeasts, used in the animal feed. In the present investigation was determined the effect of the concentration of the inoculum and the molasses as supplement of the vinasse, for the production of biomass of native Candida utilis. Yeasts were isolated of leaves of Zea mays L. "maize" in Sabouraud glucosade agar, were identified 40.23 % as C. utilis. Next, were cultivated in vinasse with 30 g/L of molasses, to 28 ºC, during 24 hours, the biomass was weighed and was selected C. utilis MKJ12, because it had the highest biomass value of 7.667 g/L. This yeast in concentration of 25, 50 and 75 mL/L of inoculum was cultivated in bioreactors Batch tank type containing 300 mL of vinasse with 10, 30, and 50 g/L of molasses, with downward air flow (1vvm, and incubation was 28 ºC during 20 hours. With 50 mL/L of inoculum and 50 g/L of molasses was determined the shortest generation time (2.88 h and the highest values in number of generations (6.95, specific rate of growth (0.35 h-1 , weight of biomass (11.78 g/L and percentage of protein (40.15 %. Feasibility was demonstrated of the production of C. utilis biomass with 5 mL of inoculum in vinasse supplemented by molasses.

  2. Efficacy of Daptomycin Monotherapy and In Combination with β-lactams for Daptomycin-Susceptible Enterococcus faecium Harboring LiaSR Substitutions: Influence of The Inoculum Effect.

    Science.gov (United States)

    Kebriaei, Razieh; Rice, Seth A; Singh, Kavindra V; Stamper, Kyle C; Dinh, An Q; Rios, Rafael; Diaz, Lorena; Murray, Barbara E; Munita, Jose M; Tran, Truc T; Arias, Cesar A; Rybak, Michael J

    2018-05-14

    Enterococcus faecium that harbor LiaFSR substitutions but are phenotypically susceptible to daptomycin (DAP) by current breakpoints are problematic since predisposition to resistance may lead to therapeutic failure. Using a simulated endocardial vegetation (SEV) PK/PD model, we investigated DAP regimens (6, 8 and 10 mg/kg/day) as monotherapy and in combination with ampicillin (AMP), ceftaroline (CPT) or ertapenem (ERT) against E. faecium HOU503, a DAP-susceptible strain that harbors common LiaS and LiaR substitutions found in clinical isolates (T120S and W73C, respectively). Of interest, the efficacy of DAP monotherapy, at any dose regimen, was dependent on the size of the inoculum. At an inoculum of ∼10 9 CFU/g, DAP doses of 6-8 mg/kg/d were not effective and led to significant regrowth with emergence of resistant derivatives. In contrast, at an inoculum of ∼10 7 , marked reductions in bacterial counts were observed with DAP 6 mg/kg/d with no resistance. The inoculum effect was confirmed in a rat model using humanized DAP exposures. Combinations of DAP with AMP, CPT or ERT demonstrated enhanced eradication and reduced potential for resistance allowing for de-escalation of the DAP dose. Persistence of the LiaRS substitutions were identified in DAP-resistant isolates recovered from the SEV model and in DAP-resistant derivatives of an initially DAP-susceptible clinical isolate of E. faecium (HOU668) harboring LiaSR substitutions and recovered from a patient with a recurrent bloodstream infection. Our results provide novel data for the use of DAP monotherapy and combinations for recalcitrant E. faecium infections and paves the way for testing these approaches in humans. Copyright © 2018 American Society for Microbiology.

  3. Extracts against Various Pathogens

    Directory of Open Access Journals (Sweden)

    Ritika Chauhan

    2013-07-01

    The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens.

  4. Evolution of microbial pathogens

    National Research Council Canada - National Science Library

    DiRita, Victor J; Seifert, H. Steven

    2006-01-01

    ... A. Hogan vvi ■ CONTENTS 8. Evolution of Pathogens in Soil Rachel Muir and Man-Wah Tan / 131 9. Experimental Models of Symbiotic Host-Microbial Relationships: Understanding the Underpinnings of ...

  5. Indicators for waterborne pathogens

    National Research Council Canada - National Science Library

    Committee on Indicators for Waterborne Pathogens, National Research Council

    2004-01-01

    ... not practical or feasible to monitor for the complete spectrum of microorganisms that may occur in water, and many known pathogens are difficult to detect directly and reliably in water samples.Â...

  6. Host–Pathogen Interactions

    NARCIS (Netherlands)

    Smits, M.A.; Schokker, D.J.

    2011-01-01

    The outcome of an infection is determined by numerous interactions between hosts and pathogens occurring at many different biological levels, ranging from molecule to population. To develop new control strategies for infectious diseases in livestock species, appropriate methodologies are needed

  7. Plasticity in early immune evasion strategies of a bacterial pathogen.

    Science.gov (United States)

    Bernard, Quentin; Smith, Alexis A; Yang, Xiuli; Koci, Juraj; Foor, Shelby D; Cramer, Sarah D; Zhuang, Xuran; Dwyer, Jennifer E; Lin, Yi-Pin; Mongodin, Emmanuel F; Marques, Adriana; Leong, John M; Anguita, Juan; Pal, Utpal

    2018-04-17

    Borrelia burgdorferi is one of the few extracellular pathogens capable of establishing persistent infection in mammals. The mechanisms that sustain long-term survival of this bacterium are largely unknown. Here we report a unique innate immune evasion strategy of B. burgdorferi , orchestrated by a surface protein annotated as BBA57, through its modulation of multiple spirochete virulent determinants. BBA57 function is critical for early infection but largely redundant for later stages of spirochetal persistence, either in mammals or in ticks. The protein influences host IFN responses as well as suppresses multiple host microbicidal activities involving serum complement, neutrophils, and antimicrobial peptides. We also discovered a remarkable plasticity in BBA57-mediated spirochete immune evasion strategy because its loss, although resulting in near clearance of pathogens at the inoculum site, triggers nonheritable adaptive changes that exclude detectable nucleotide alterations in the genome but incorporate transcriptional reprograming events. Understanding the malleability in spirochetal immune evasion mechanisms that ensures their host persistence is critical for the development of novel therapeutic and preventive approaches to combat long-term infections like Lyme borreliosis.

  8. Radiophosphorous in vitro incorporation by rumen microorganisms in different inoculum proportions; Incorporacao in vitro do radiofosforo pelos microorganismos ruminais em diferentes proporcoes do inoculo

    Energy Technology Data Exchange (ETDEWEB)

    Cabral Filho, Sergio Luiz Salomon; Gobbo, Sarita Priscila; Bueno, Ives Claudio da Silva; Machado, Mariana de Carvalho; Nozella, Eduardo Fernando; Abdalla, Adibe Luiz [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    2002-07-01

    Estimation of rumen microbial population activity is an important parameter on feed evaluation. Increases on microbial population have a positive correlation with increases on protein supply for ruminant animal. In vitro methodology is based on relationships between {sup 32} P and N incorporation for the rumen microorganisms. The objective of this paper was to test different types of inoculum in {sup 32} P microbial incorporation technique. Treatments were two different types of inoculum (rumen content), where one of them has only liquid phase and the other has 50% liquid and 50% solid phase. Five different feedstuffs were used as substrate (corn grain, maize silage, soybean meal, alfalfa hay and Panicum grass). The incubation was done in plastics tubes containing 1 g of substrate, buffer solution (4ml), 16ml of inoculum and 25{mu}l of {sup 32} P-labelled phosphate solution (3700 Bq). Nitrogen incorporation (N{sub i}) into microbial mass was between 2,9 to 13,6 mg of N{sub i}, g DM{sup -1}. Treatments did not differ statistical (P>0,05), but treatments and substrate interaction was significant (P<0,05) for Panicum grass. Results did not demonstrated advantage to use solid phase in {sup 32} P technique, however significant interaction suggest more studies with roughages. (author)

  9. Influence of arbuscular mycorrhizal fungi inoculum produced on-farm and phosphorus on growth and nutrition of native woody plant species from Brazil

    Directory of Open Access Journals (Sweden)

    Luis Claudio Goetten

    2016-03-01

    Full Text Available Mycorrhizal fungus inoculum produced on-farm can be used during production of woody plant seedlings to reduce costs associated with purchase of commercial inoculant and fertilization. This study aimed to test the efficiency of a mycorrhizal inoculant produced on-farm to promote growth and nutrition of woody species in combination with different levels of phosphorus. Plants were submitted to different treatments of phosphorus (0, 40 and 80 mg P/dm3 and mycorrhizal inoculation (uninoculated, and inoculation with Rhizophagus clarus [Rc] or Claroideoglomus etunicatum [Ce]. Species included were Luehea divaricata, Centrolobium robustum, Schinus terebinthifolius, Garcinia gardneriana, Cedrella fissilis, and Lafoensia pacari. The inoculum was produced using the on-farm methodology. Mycorrhizal colonization of plants inoculated with Rc and Ce ranged from 44.8 to 74.8%, except forGarcinia gardneriana. Inoculation treatment increased plant height and stem diameter of Luehea divaricata, Centrolobium robustum and Cedrella fissilis while phosphorus, inoculation and the interaction affected these parameters for G. gardneriana and Lafoensia pacari. Shoot biomass increased significantly with inoculation treatment in four species. For most species, mycorrhizal fungus inoculation and the addition of phosphorus increased the shoot phosphorus content. Mycorrhizal fungus inoculum produced on-farm successfully colonized tree seedlings and improved growth and/or nutrition under nursery conditions, producing seedlings useful for revegetation of degraded lands.

  10. Pre-acclimation of a wastewater inoculum to cellulose in an aqueous–cathode MEC improves power generation in air–cathode MFCs

    KAUST Repository

    Cheng, Shaoan

    2011-01-01

    Cellulose has been used in two-chamber microbial fuel cells (MFCs), but power densities were low. Higher power densities can be achieved in air-cathode MFCs using an inoculum from a two-chamber, aqueous-cathode microbial electrolysis cell (MEC). Air-cathode MFCs with this inoculum produced maximum power densities of 1070mWm-2 (cathode surface area) in single-chamber and 880mWm-2 in two-chamber MFCs. Coulombic efficiencies ranged from 25% to 50%, and COD removals were 50-70% based on total cellulose removals of 60-80%. Decreasing the reactor volume from 26 to 14mL (while maintaining constant electrode spacing) decreased power output by 66% (from 526 to 180mWm-2) due to a reduction in total mass of cellulose added. These results demonstrate that air-cathode MFCs can produce high power densities with cellulose following proper acclimation of the inoculum, and that organic loading rates are important for maximizing power densities from particulate substrates. © 2010 Elsevier Ltd.

  11. Effect of different accellerators and inoculums used in fermentation on quality of dead chicken silage flour as feed ingredient for catfish

    Directory of Open Access Journals (Sweden)

    B. Bakrie

    2017-05-01

    Full Text Available This research aimed at investigating the effect using molasses and cornmeal as additives with Lactobacillus sp. and Streptomyces sp. as inoculums during fermentation on the quality of silage flour made from dead chickens. The study was conducted using a completely randomized factorial design, consisting of 2 factors with 5 replications. The materials used were the newly dead chickens which were chopped and mixed thoroughly with all ingredients; then transferred into a 5 liters plastic box for fermentation. Observations were made after 3 weeks fermentation, including: a physical characteristics, b microbial contents, and c nutritional contents. The data were calculated using variance analysis utilizing computer program of SPSS version 21.0. It was found that based on the protein contents the Lactobacillus sp. (19.0% was better than the Streptomyces sp. (17.8% if combined with molasses and corn meal as the accelerators. However, the fat contents produced were relatively similar for both of the inoculums (mean of 37.8%. It can be concluded that in order to obtain a best fermented product in terms of the protein and fat content, the dead chicken should be fermented using molasses and cornmeal as the accelerator and Lactobacillus sp. as the inoculum.

  12. Effects of Aspergillus niger inoculum concentration upon the kinetics of starchy wastewater pretreatment in a tanks-in-series bioreactor under transitory conditions

    Directory of Open Access Journals (Sweden)

    L. Coulibaly

    2007-12-01

    Full Text Available This paper discusses the effects of three Aspergillus niger inoculum concentrations (0.12, 2.3 and 3.6 g/l upon the kinetics of starch pretreatment under aerobic and transitory conditions using a tanks-in-series reactor. A synthetic wastewater containing starch as model polysaccharide was fed into the reactor system to study this polymer transformation by Aspergillus niger. Starch and metabolites (oligosaccharides with a molecular weight lower than 1 kDa in the individual reactors were quantified respectively by the starch iodine complex (SIC and anthrone methods. Enzyme activities were characterised with API ZYM kits. Starch degradation and metabolite accumulation were both influenced by both fungal inoculum and reactor HRT. Starch degradation improved from 34 to 99% with a parallel in increase inoculum concentration from 0.12 to 3.6 g/l. An overall of 400 mg/l of metabolites accumulated in the reactor system. A. niger secreted both extracellular and cell-wall-bound enzymes among which amylases.

  13. Effect of incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder on ACE inhibitory activity in fermented milk by L. plantarum LP69.

    Science.gov (United States)

    Shu, Guowei; Yang, Hui; Chen, He; Zhang, Qiuhong; Tian, Yue

    2015-01-01

    Angiotensin I converting enzyme (ACE) plays an important physiological role in regulating hypertension. Lactic acid bacteria are known to produce ACE inhibitory peptides which can lower hypertension during fermentation. The effect of incubation time (0~36 h), inoculum size (3, 4, 5, 6 and 7%, v/v), temperature (25, 30, 35, 40 and 45°C), sterilization time (5, 10, 15, 20 and 25 min), concentration of goat milk powder (8, 10, 12, 14 and 16%, w/v) and whey powder (0.5, 0.6, 0.7, 0.8 and 0.9%, w/v) on ACE inhibitory peptides fermented from goat milk by Lactobacillus plantarum LP69 was investigated using single factor experiment. The optimal incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder in fermented milk by L. plantarum LP69 was 14 h, 3.0%, 35°C, 20 min, 14% and 0.70% for ACE inhibitory activity and 22 h, 3.0%, 40°C, 25 min, 16% and 0.60% for viable cell counts, respectively. The incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder had a significant influence on ACE inhibitory activity in fermented milk by Lactobacillus plantarum LP69, the results are beneficial for further screening of main factors by using fractional factorial designs.

  14. Effect of Various Inoculum Levels of Multidrug-Resistant Salmonella enterica Serovar Heidelberg (2011 Ground Turkey Outbreak Isolate on Cecal Colonization, Dissemination to Internal Organs, and Deposition in Skeletal Muscles of Commercial Turkeys after Experimental Oral Challenge

    Directory of Open Access Journals (Sweden)

    Divek V. T. Nair

    2018-01-01

    Full Text Available Salmonella enterica serovar Heidelberg (S. Heidelberg is a major foodborne pathogen colonizing poultry. The pathogen is associated with a significant number of foodborne outbreaks through contaminated poultry meat, including turkeys. Recently, multidrug-resistant (MDR strains of S. Heidelberg have emerged as a threat to human public health in the United States. The objective of this study was to determine the cecal colonization, dissemination to internal organs, and the potential for skeletal muscle deposition of an MDR S. Heidelberg isolate from the 2011 ground turkey outbreak in the United States after the experimental oral challenge of poults (young turkeys and adult turkey hens. In the poult study, two separate experiments using day-old, straight-run, commercial hybrid converter poults were randomly assigned to five challenge groups (0, 10∧2, 10∧4, 10∧6, 10∧8 CFU groups; 12 poults/group; N = 60/experiment and a week after, treatment groups were challenged separately with 0-, 2-, 4-, 6-, and 8- log10 CFU of S. Heidelberg orally. After 14 days post-challenge, the poults were euthanized, and samples were collected to determine MDR S. Heidelberg colonization in the cecum, dissemination to liver and spleen, and deposition in the thigh, drumstick, and breast muscles. A similar experimental design was followed for the adult turkey hens. In two separate experiments, 11-week-old commercial Hybrid Converter turkey hens (4 hens/group; N = 20/experiment were challenged with MDR S. Heidelberg and on day 16 post-challenge, birds were euthanized and samples were collected to determine Salmonella populations in the samples. The results indicated that, in turkey poults, the recovery of MDR S. Heidelberg was highest in the cecum followed by spleen, liver, thigh, drumstick, and breast. All tested inoculum levels resulted in more than 3.5 log10 CFU/g colonization in the poult cecum. The cecal colonization, dissemination to internal organs, and tissue

  15. The Effect of Initial Inoculum Source on the Microbial Community Structure and Dynamics in Laboratory-Scale Sequencing Batch Reactors

    KAUST Repository

    Hernandez, Susana

    2011-07-01

    Understanding the factors that shapes the microbial community assembly in activated sludge wastewater treatment processes provide a conceptual foundation for improving process performance. The aim of this study was to compare two major theories (deterministic theory and neutral theory) regarding the assembly of microorganisms in activated sludge: Six lab-scale activated sludge sequencing batch reactors were inoculated with activated sludge collected from three different sources (domestic, industrial, and sugar industry WWTP). Additionally, two reactors were seeded with equal proportion of sludge from the three WWTPs. Duplicate reactors were used for each sludge source (i.e. domestic, industrial, sugar and mix). Reactors were operated in parallel for 11 weeks under identical conditions. Bacterial diversity and community structure in the eight SBRs were assessed by 16S rRNA gene pyrosequencing. The 16S rRNA gene sequences were analyzed using taxonomic and clustering analysis and by measuring diversity indices (Shannon-weaver and Chao1 indices). Cluster analysis revealed that the microbial community structure was dynamic and that replicate reactors evolved differently. Also the microbial community structure in the SBRs seeded with a different sludge did not converge after 11 weeks of operation under identical conditions. These results suggest that history and distribution of taxa in the source inoculum were stronger regulating factors in shaping bacterial community structure than environmental factors. This supports the neutral theory which states that the assembly of the local microbial community from the metacommunity is random and is regulated by the size and diversity of the metacommunity. Furthermore, sludge performance, measured by COD and ammonia removal, confirmed that broad-scale functions (e.g. COD removal) are not influenced by dynamics in the microbial composition, while specific functions (e.g. nitrification) are more susceptible to these changes.

  16. Effect of modified atmosphere packaging (MAP) with low and superatmospheric oxygen on the quality and antioxidant enzyme system of golden needle mushrooms (Flammulina velutipes) during postharvest storage

    NARCIS (Netherlands)

    Wang, Cheng T.; Wang, Chang T.; Cao, Y.P.; Nout, M.J.R.; Sun, B.G.; Liu, L.

    2011-01-01

    To quantify the effect of oxygen concentrations on the quality and antioxidant enzyme system of stored golden needle mushroom, modified atmosphere packaging (MAP) with low and initial superatmospheric oxygen was applied during mushroom storage, and physiological changes associated with postharvest

  17. Data on the no-load performance analysis of a tomato postharvest storage system.

    Science.gov (United States)

    Ayomide, Orhewere B; Ajayi, Oluseyi O; Banjo, Solomon O; Ajayi, Adesola A

    2017-08-01

    In this present investigation, an original and detailed empirical data on the transfer of heat in a tomato postharvest storage system was presented. No-load tests were performed for a period of 96 h. The heat distribution at different locations, namely the top, middle and bottom of the system was acquired, at a time interval of 30 min for the test period. The humidity inside the system was taken into consideration. Thus, No-load tests with or without introduction of humidity were carried out and data showing the effect of a rise in humidity level, on temperature distribution were acquired. The temperatures at the external mechanical cooling components were acquired and could be used for showing the performance analysis of the storage system.

  18. Food irradiation - a viable technology for reducing postharvest losses of food

    International Nuclear Information System (INIS)

    Loaharanu, P.

    1985-01-01

    Research and development in the past 30 years have clearly demonstrated that food irradiation is a safe, effective and environmentally clean process of food preservation. Twenty-seven countries have approved over 40 irradiated foods or groups of related food items for human consumption, either on an unconditional or a restricted basis. The technology is beginning to play an important role in reducing post-harvest losses of food and in facilitating wider distribution of food in the trade. Its wide application in solving microbial spoilage losses of food, insect disinfestation, improving hygienic qualities, slowing down physiological processes of foods is reviewed. Special emphasis is placed on applications of direct relevance to countries in Asia and the Pacific region

  19. Effect of post-harvest treatment on bioactive phytochemicals of Thai black rice.

    Science.gov (United States)

    Norkaew, Orranuch; Boontakham, Pittayaporn; Dumri, Kanchana; Noenplab, Acharaporn Na Lampang; Sookwong, Phumon; Mahatheeranont, Sugunya

    2017-02-15

    Because black rice is rich in antioxidants, appropriate methods of post-harvest treatment are necessary for maintaining these bioactive phytochemicals. Drying methods, storage temperatures, storage duration, and packaging methods affected the contents of some bioactive compounds in the two varieties of Thai black rice used in this research. Sun drying reduces the loss of anthocyanins and γ-oryzanols more than does hot air drying. Glutinous black rice stored as paddy at cool room temperature retains more anthocyanins, γ-oryzanols, and vitamin E than does paddy stored at room temperature. Nylon/LLDPE pouches containing N2 are the most suitable packaging for preserving the key aroma compound 2-acetyl-1-pyrroline (2AP), total phenolic, and anthocyanin contents of unpolished aromatic black rice. These pouches also retard the formation of some common off-flavor compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Radiation processing as a post-harvest quarantine control for raisins, dried figs and dried apricots

    International Nuclear Information System (INIS)

    Cetinkaya, N.; Ozyardimci, B.; Denli, E.; Ic, E.

    2006-01-01

    The commercially packed samples of raisins, dried figs and dried apricots were irradiated using doses in the range of 0.5-1.0 kGy for disinfestation and 0.5-5.0 kGy for sensory analysis with the dose rate ranging from 1.44 to 1.92 kGy/h. Pests on dried fruits were evaluated after 0, 1, 2 and 3 months of storage for irradiated dried figs and 1, 3, 6 and 12 months of storage for raisins and dried apricots. Sensory analysis of dried figs, dried apricots and raisins were carried out after 0, 1, 3, 6 and 12 months of storage. The results indicated that radiation processing at low doses (∼1.0 kGy) is an effective post-harvest treatment and quarantine control for these products with no adverse effects on sensory (marketing) attributes

  1. Effects of elevated temperature postharvest on color aspect, physiochemical characteristics, and aroma components of pineapple fruits.

    Science.gov (United States)

    Liu, Chuanhe; Liu, Yan

    2014-12-01

    In this work, 2 separate experiments were performed to describe the influence of elevated temperature treatments postharvest on the color, physiochemical characteristics and aroma components of pineapple fruits during low-temperature seasons. The L* (lightness) values of the skin and pulp of pineapple fruits were decreased. The a* (greenness-redness) and b* (blueness-yellowness) values of the skin and pulp were all markedly increased. The elevated temperature significantly increased the contents of total soluble solids (TSS) and slightly affected contents of vitamin C (nonsignificant). Titratable acidity (TA) of pineapple fruits were notably decreased, whereas the values of TSS/TA of pineapple fruits were significantly increased. The firmness of the pineapple fruits decreased and more esters and alkenes were identified. The total relative contents of esters were increased, and the total relative contents of alkenes were decreased. © 2014 Institute of Food Technologists®

  2. Radiation processing as a post-harvest quarantine control for raisins, dried figs and dried apricots

    Energy Technology Data Exchange (ETDEWEB)

    Cetinkaya, N. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey)]. E-mail: nurcet@taek.gov.tr; Ozyardimci, B. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey); Denli, E. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey); Ic, E. [TAEA, Ankara Nuclear Research Center in Agriculture and Animal Sciences, 06983 Ankara (Turkey)

    2006-03-15

    The commercially packed samples of raisins, dried figs and dried apricots were irradiated using doses in the range of 0.5-1.0 kGy for disinfestation and 0.5-5.0 kGy for sensory analysis with the dose rate ranging from 1.44 to 1.92 kGy/h. Pests on dried fruits were evaluated after 0, 1, 2 and 3 months of storage for irradiated dried figs and 1, 3, 6 and 12 months of storage for raisins and dried apricots. Sensory analysis of dried figs, dried apricots and raisins were carried out after 0, 1, 3, 6 and 12 months of storage. The results indicated that radiation processing at low doses ({approx}1.0 kGy) is an effective post-harvest treatment and quarantine control for these products with no adverse effects on sensory (marketing) attributes.

  3. Split double factorial with additional treatment and the post-harvest of Niagara grapes

    Directory of Open Access Journals (Sweden)

    Pórtya Piscitelli Cavalcanti

    2015-09-01

    Full Text Available ABSTRACTThis study aims to discuss and explain how to deal with the analysis of experiments conducted in completely randomized design (CRD and subdivided into double factorial with additional treatment in the plot. In addition it was illustrate the discussion by analyzing data from an experiment on post-harvest of Niagara grapes. The sums of squares for each source of variation are presented, while discussing how the additional treatment affects the whole variation. Niagara grapes were treated in the pre-harvest with three preservatives (calcium chloride, calcium nitrate and calcium lactate at 0%, 0.5%, 1% and 2% and stored for 0, 10, 20 and 30 days.All the preservatives evaluated at 0% represented the control (additional treatment.

  4. Effects of inoculum source and co-digestion strategies on anaerobic digestion of residues generated in the treatment of waste vegetable oils.

    Science.gov (United States)

    Hidalgo, Dolores; Martín-Marroquín, Jesús M

    2014-09-01

    This work aims at selecting a suitable strategy to improve the performance of the anaerobic digestion of residues generated in the treatment of waste vegetable oils (WVO). Biochemical methane potential (BMP) assays were conducted at 35 °C to evaluate the effects of substrate mix ratio between a mixture of WVO residues (M) and pig manure (PM) co-digesting by using different inocula. Inoculum from an industrial digester fed with organic waste from hotels, restaurants and catering leftovers (HORECA) showed higher methanogenic activity (55.5 mLCH4 gVS(-1) d(-1)) than municipal wastewater treatment plant (mWWTP) inoculum (42.6 mL CH4 gVS(-1) d(-1)). Furthermore, the results showed that the resistance to WVO residues toxicity was higher for the HORECA sludge than for the mWWTP sludge. HORECA inoculum produced more biogas in all the assays. Moreover, the resulting biogas was of better quality, containing an average of 71.1% (SD = 1.6) methane compared to an average of 69.5% (SD = 1.2) methane for test with mWWTP sludge. The maximum degradation rate occurred at the higher PM mix ratio (M/PM:1/3), reaching 26.7 ± 4.3 mLCH4 gVS(-1) d(-1) for mWWTP inoculum, versus 42.0 ± 1,5 mLCH4 gVS(-1) d(-1) achieved for HORECA inoculum. A high reduction of volatile solids (between 70% and 81%) was obtained with both inocula at all M/PM ratios assayed (1/0, 1/3, 1/1 and 3/1 v/v) but, bearing in mind the operation of a full-scale anaerobic plant, the optimal scenario assayed corresponds to the ratio M/PM: 1/3 v/v where shorter lag periods will make it possible to operate at lower hydraulic retention times. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Postharvest transfer and survival of Salmonella enterica serotype enteritidis on living lettuce.

    Science.gov (United States)

    Waitt, J A; Kuhn, D D; Welbaum, G E; Ponder, M A

    2014-02-01

    The potential for postharvest transfer of Salmonella to 'living lettuce' is not well understood. In this study, the transfer of Salmonella enterica Enteritidis (6 log CFU g(-1) ) from worker hands or contaminated roots to leaves of living lettuce was quantified. Transfer rates of Salmonella from contaminated gloves to sequentially handled lettuce heads ranged from 94% to head 1, 82% to head 2 and 69% to head 3. On average, 2.9 ± 0.1 log CFU g(-1) (64%) Salmonella was transferred from inoculated roots to leaves resulting from typical postharvest handling activities for living lettuce. Salmonella persisted on leaves stored at recommended storage temperatures (4°C) and increased 0.5 log CFU g(-1) when stored at temperature abuse conditions (12°C). Salmonella increased 1.6 log CFU g(-1) on roots after 18-day storage at 12°C, emphasizing the need to maintain temperature control to reduce the risk of human illness. Hydroponically grown lettuce packaged in plastic clamshells with intact roots, marketed as 'living lettuce', is increasing in popularity due to its extended shelf life. This study demonstrates the transfer of Salmonella from contaminated worker hands and contaminated roots to leaves where it persisted at 4°C for 18 day. Temperature abuse (12°C) increased Salmonella on roots and leaves. These findings suggest that failure to maintain temperatures below 12°C can pose a risk for consumers purchasing living lettuce at markets where recommended storage temperatures are not maintained. © 2013 The Society for Applied Microbiology.

  6. Effect of postharvest dehydration on the composition of pinot noir grapes (Vitis vinifera L.) and wine.

    Science.gov (United States)

    Moreno, Jorge J; Cerpa-Calderón, Fiorella; Cohen, Seth D; Fang, Yu; Qian, Michael; Kennedy, James A

    2008-08-15

    This study was conducted in order to improve our understanding of how phenolics and aroma compounds change in wine grapes during postharvest dehydration. Pinot noir grapes grown in the Willamette Valley of Oregon were harvested at 22.0 and 24.0°Brix. Grapes harvested at 22.0°Brix were divided into three equal lots with one lot immediately used for wine production, and the remaining two lots placed inside an air tunnel with an air speed of 1.0-1.8ms(-1), 38% relative humidity and a temperature of 22°C. The soluble solids content and weight loss were measured daily and wines were made from grapes when they reached 24.8 and 26.7°Brix. The soluble solids of grapes increased about 1°Brix per day; therefore, on the third and fourth day the berries reached the desired concentration; weight loss was 14 and 16%, respectively. Results from berry phenolic analysis indicated that per berry anthocyanin amount remained unchanged during dehydration. The composition of proanthocyanidins isolated from berries changed during dehydration. Volatile compounds in wines made from dehydrated grapes contained more terpenes and norisoprenoids (β-ionone, β-damascenone) when compared to wine made from the original fruit. Wines made from increasingly dehydrated grapes tended to resemble the composition and flavour profile of wines made from grapes left on the vine (i.e. with extended ripening). The results of this study suggest that postharvest flavour changes consistent with changes during fruit ripening can occur in grapes when harvested early and allowed to dehydrate under controlled conditions prior to fermentation. Copyright © 2008 Elsevier Ltd. All rights reserved.

  7. Transcriptome profiling of postharvest strawberry fruit in response to exogenous auxin and abscisic acid.

    Science.gov (United States)

    Chen, Jingxin; Mao, Linchun; Lu, Wenjing; Ying, Tiejin; Luo, Zisheng

    2016-01-01

    Auxin and abscisic acid regulate strawberry fruit ripening and senescence through cross-talk of their signal transduction pathways that further modulate the structural genes related to physico-chemical properties of fruit. The physiological and transcriptomic changes in harvested strawberry fruits in responses to IAA, ABA and their combination were analyzed. Exogenous IAA delayed the ripening process of strawberries after harvest while ABA promoted the postharvest ripening. However, treatment with a combination of IAA and ABA did not slow down nor accelerate the postharvest ripening in the strawberry fruits. At the molecular level, exogenous IAA up regulated the expressions of genes related to IAA signaling, including AUX/IAA, ARF, TOPLESS and genes encoding E3 ubiquitin protein ligase and annexin, and down regulated genes related to pectin depolymerization, cell wall degradation, sucrose and anthocyanin biosyntheses. In contrast, exogenous ABA induced genes related to fruit softening, and genes involved in signaling pathways including SKP1, HSPs, CK2, and SRG1. Comparison of transcriptomes in responses to individual treatments with IAA or ABA or the combination revealed that there were cooperative and antagonistic actions between IAA and ABA in fruit. However, 17% of the differentially expressed unigenes in response to the combination of IAA and ABA were unique and were not found in those unigenes responding to either IAA or ABA alone. The analyses also found that receptor-like kinases and ubiquitin ligases responded to both IAA and ABA, which seemed to play a pivotal role in both hormones' signaling pathways and thus might be the cross-talk points of both hormones.

  8. Effect of Post-Harvest Treatments on Enzyme Activity and Quality of Cold Stored Ber Fruit

    Directory of Open Access Journals (Sweden)

    Sukhjit K. JAWANDHA

    2012-11-01

    Full Text Available Ber (Zizyphus mauritiana Lamk fruits are perishable in nature and have poor shelf- life. To extend the storage life of ber fruits different post-harvest treatments, like CaCl2 (0.5, 1.0 and 2.0%, Ca(NO32 (0.5, 1.0 and 2.0%, gibberellic acid (GA3 (20, 40 and 60 ppm and Bavistin (0.1% were given to fruits and their effect was studied on the storage life and quality of �Umran� ber (Zizyphus mauritiana Lamk fruits under cold storage conditions. Fruits of uniform size and colour were harvested, from healthy plants, and subjected to post harvest dip of different chemicals, before packing in CFB boxes and placed in cold storage (3-5�C and 85-90% RH They have been evaluated after 10, 20 and 30 days of storage for physiological loss in weight (PLW, firmness, pectin methyl esterase (PME activity and palatability rating. The PLW increased and fruit firmness decreased during storage at each treatment. The sensory rating increased up to 10 days at all treatments, except control but subsequently it decreased during storage. The increase rate in PME activity was faster, up to 10 days, in untreated fruits, while treated fruits showed slower rise in PME activity, up to 20 days with a decline afterwards. It can be concluded that ber fruits can be stored up to 20 days by post-harvest treatment using GA3 at 60 ppm, with acceptable quality.

  9. Variation in cassava germplasm for tolerance to post-harvest physiological deterioration.

    Science.gov (United States)

    Venturini, M T; Santos, L R; Vildoso, C I A; Santos, V S; Oliveira, E J

    2016-05-06

    Tolerant varieties can effectively control post-harvest physiological deterioration (PPD) of cassava, although knowledge on the genetic variability and inheritance of this trait is needed. The objective of this study was to estimate genetic parameters and identify sources of tolerance to PPD and their stability in cassava accessions. Roots from 418 cassava accessions, grown in four independent experiments, were evaluated for PPD tolerance 0, 2, 5, and 10 days post-harvest. Data were transformed into area under the PPD-progress curve (AUP-PPD) to quantify tolerance. Genetic parameters, stability (Si), adaptability (Ai), and the joint analysis of stability and adaptability (Zi) were obtained via residual maximum likelihood (REML) and best linear unbiased prediction (BLUP) methods. Variance in the genotype (G) x environment (E) interaction and genotypic variance were important for PPD tolerance. Individual broad-sense heritability (hg(2)= 0.38 ± 0.04) and average heritability in accessions (hmg(2)= 0.52) showed high genetic control of PPD tolerance. Genotypic correlation of AUP-PPD in different experiments was of medium magnitude (ȓgA = 0.42), indicating significant G x E interaction. The predicted genotypic values o f G x E free of interaction (û + ĝi) showed high variation. Of the 30 accessions with high Zi, 19 were common to û + ĝi, Si, and Ai parameters. The genetic gain with selection of these 19 cassava accessions was -55.94, -466.86, -397.72, and -444.03% for û + ĝi, Si, Ai, and Zi, respectively, compared with the overall mean for each parameter. These results demonstrate the variability and potential of cassava germplasm to introduce PPD tolerance in commercial varieties.

  10. INFLUÊNCIA DA DENSIDADE DE INÓCULO DE Fusarium solani f.sp. phaseoli NA SEVERIDADE DA PODRIDÃO RADICULAR SECA DO FEIJOEIRO EFFECT OF Fusarium solani f.sp. phaseoli INOCULUM DENSITY ON DRY ROOT ROT SEVERITY IN THE COMMON BEAN

    Directory of Open Access Journals (Sweden)

    Gesimária Ribeiro Costa

    2007-09-01

    . The results indicated that the minimum inoculum density for disease occurrence varied with the soil type. For a non-cultivated soil, the minimum inoculum density was greater than 5,127 propagules per gram of soil, while for cultivated soil, the minimum inoculum density was 3,701 propagules per gram of soil. Disease severity in seedlings grown in cultivated soil was twice as great as for those grown in non-cultivated soil. Total soil microbial activity, as determined by dehydrogenase of fluorescein diacetate, did not correlate with the population of the pathogen, indicating that the mere presence of these organisms in the samesoils does not imply that they are active.

    KEY-WORDS: Suppressive soil; conducive soil; Phaseolus vulgaris.

  11. The phytopathogen Dickeya dadantii (Erwinia chrysanthemi 3937) is a pathogen of the pea aphid.

    Science.gov (United States)

    Grenier, Anne-Marie; Duport, Gabrielle; Pagès, Sylvie; Condemine, Guy; Rahbé, Yvan

    2006-03-01

    Dickeya dadantii (Erwinia chrysanthemi) is a phytopathogenic bacterium causing soft rot diseases on many crops. The sequencing of its genome identified four genes encoding homologues of the Cyt family of insecticidal toxins from Bacillus thuringiensis, which are not present in the close relative Pectobacterium carotovorum subsp. atrosepticum. The pathogenicity of D. dadantii was tested on the pea aphid Acyrthosiphon pisum, and the bacterium was shown to be highly virulent for this insect, either by septic injury or by oral infection. The lethal inoculum dose was calculated to be as low as 10 ingested bacterial cells. A D. dadantii mutant with the four cytotoxin genes deleted showed a reduced per os virulence for A. pisum, highlighting the potential role of at least one of these genes in pathogenicity. Since only one bacterial pathogen of aphids has been previously described (Erwinia aphidicola), other species from the same bacterial group were tested. The pathogenic trait for aphids was shown to be widespread, albeit variable, within the phytopathogens, with no link to phylogenetic positioning in the Enterobacteriaceae. Previously characterized gut symbionts from thrips (Erwinia/Pantoea group) were also highly pathogenic to the aphid, whereas the potent entomopathogen Photorhabdus luminescens was not. D. dadantii is not a generalist insect pathogen, since it has low pathogenicity for three other insect species (Drosophila melanogaster, Sitophilus oryzae, and Spodoptera littoralis). D. dadantii was one of the most virulent aphid pathogens in our screening, and it was active on most aphid instars, except for the first one, probably due to anatomical filtering. The observed difference in virulence toward apterous and winged aphids may have an ecological impact, and this deserves specific attention in future research.

  12. Viral pathogen discovery

    Science.gov (United States)

    Chiu, Charles Y

    2015-01-01

    Viral pathogen discovery is of critical importance to clinical microbiology, infectious diseases, and public health. Genomic approaches for pathogen discovery, including consensus polymerase chain reaction (PCR), microarrays, and unbiased next-generation sequencing (NGS), have the capacity to comprehensively identify novel microbes present in clinical samples. Although numerous challenges remain to be addressed, including the bioinformatics analysis and interpretation of large datasets, these technologies have been successful in rapidly identifying emerging outbreak threats, screening vaccines and other biological products for microbial contamination, and discovering novel viruses associated with both acute and chronic illnesses. Downstream studies such as genome assembly, epidemiologic screening, and a culture system or animal model of infection are necessary to establish an association of a candidate pathogen with disease. PMID:23725672

  13. Highly pathogenic avian influenza.

    Science.gov (United States)

    Swayne, D E; Suarez, D L

    2000-08-01

    Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

  14. Tryptanthrin content in Isatis tinctoria leaves--a comparative study of selected strains and post-harvest treatments.

    Science.gov (United States)

    Oberthür, Christine; Hamburger, Matthias

    2004-07-01

    Tryptanthrin is a pharmacologically active compound in the anti-inflammatory herb Isatis tinctoria, with potent inhibitory activity on prostaglandin and leukotriene synthesis and on inducible NO synthase. The tryptanthrin content of five defined woad strains was analyzed in dependence of the time of harvest and post-harvest treatment. Tryptanthrin was determined by a validated ESI-LC-MS isotope dilution assay with d(8)-tryptanthrin as internal standard. The tryptanthrin concentration in freeze-dried leaf samples was low. Drying at ambient temperature led to a significant increase of tryptanthrin concentration, but the highest concentrations were found when leaves were dried at 40 degrees C. Tryptanthrin content in fermented woad leaves was below the limit of quantification. Tryptanthrin appears thus to be a product of post-harvest processes, but details of its formation remain to be elucidated.

  15. Effect of gamma irradiation and its convergent treatment for control of postharvest Botrytis cinerea of cut roses

    Science.gov (United States)

    Chu, Eun-Hee; Shin, Eun-Jung; Park, Hae-Jun; Jeong, Rae-Dong

    2015-10-01

    Postharvest diseases cause considerable losses to harvested crops. Among them, gray mold (Botrytis cinerea) is a major problem of exporting to cut rose flowers into Korea. Irradiation treatment is an alternative to phytosanitary purposes and a useful nonchemical approach to the control of postharvest diseases. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against B. cinerea on cut rose varieties, 'Shooting Star' and 'Babe'. The irradiating dose required to reduce the population by 90%, D10, was 0.99 kGy. Gamma irradiation showed complete inhibition of spore germination and mycelial growth of B. cinerea, especially 4.0 kGy in vitro. Antifungal activity of gamma irradiation on rose B. cinerea is a dose-dependent manner. A significant phytotoxicity such as bent neck in cut rose quality was shown from gamma irradiation at over 0.4 kGy (ptechnology for horticulture products for exportation.

  16. Post-harvest treatments in smooth-stalked meadow grass (Poa pratensis L.) - effect on carbohydrates and tiller development

    DEFF Research Database (Denmark)

    Boelt, Birte

    2007-01-01

    Temperate grass species require a period of short days/low temperature to respond to flower induction stimuli. The same environmental conditions stimulate the increase in carbohydrate concentration in aboveground biomass and the accumulation of reserve carbohydrates in the basal plant parts....... The present investigation was initiated to investigate the effect of post-harvest treatments on dry matter production in autumn, carbohydrate content, the number of reproductive tillers and seed yield in a turf-type cultivar ‘Conni' of smooth-stalked meadow grass. The results show that post-harvest treatments...... harvest and all residues removed. The results from plant samples in autumn indicate that decreasing aboveground biomass production leads to a higher carbohydrate concentration which may stimulate the reproductive development in smooth-stalked meadow grass....

  17. Control of postharvest diseases of fruit by heat and fungicides: efficacy, residue levels, and residue persistence. A review.

    Science.gov (United States)

    Schirra, Mario; D'Aquino, Salvatore; Cabras, Paolo; Angioni, Alberto

    2011-08-24

    Extensive research has been done in recent years to reduce the heavy dependence on chemical fungicides to control postharvest diseases and disorders of horticultural crops. Alternative strategies were based on improved cultural practices, biological control, plant-defense promoters, and physical treatments such as UV illumination, radiofrequency treatment, heat therapy, and storage technologies. Among these, postharvest heat treatments such as hot water dips, short hot water rinsing and brushing, and hot air conditioning have reduced rot development and enhanced fruit resistance to chilling injury in sensitive cultivars while retaining fruit quality during cold storage and shelf life. Additive or synergistic increases in effectiveness were observed by integrating heat therapy with various chemical compounds, thus leading to significant reductions in the application of active ingredients to protect produce from decay. This paper highlights the knowledge on this topic with emphasis on heat therapy effects and factors affecting the uptake, persistence, and performance of fungicide residues when they are applied in combination with hot water.

  18. Populations and identification of fungi causing postharvest molds, on pineapple peduncles in two regions in Costa Rica

    Directory of Open Access Journals (Sweden)

    Johanny Castro Chinchilla

    2015-11-01

    Full Text Available Pineapple peduncle mold is an important postharvest problem in Costa Rica and it causes fruit rejection. The objective of this study was to identify and quantify the most important fungi in different postharvest phases. Monthly samplings were performed during one production year in 2 regions of Costa Rica. The main genera of fungi were identified and characterized at the molecular level. The colony forming units (CFU were determined in disinfection water, wax, cooling rooms air and in the peel and peduncle of fruits before (NP and after (P processing with the common postharvest treatments of the farms. Fruits were stored in cooling rooms during 22 days and at the end incidence and severity of peduncle molds were evaluated. During the year, changes in fungi populations were observed in all postharvest phases and in the fruits, with higher populations in wax than in disinfection water. Fungi population and molds were higher in the peduncle of NP fruits as compared with P fruits, coincident with larger mold populations at the end of storage. Fungi recovered in the cooling rooms air could also be a source for peduncle molds development. Penicillium purpureogenum, P. diversum and Penicllium sp., were the main fungi identified, with an in vitro high sporulation rate and growing in the peduncle. Moreover, different commercial practices, such as waxing and cooling, where spores were captured, can enhance the peduncle molds development, so it is considered important the cleaning of cooling rooms, as well as developing mechanisms to avoid accumulation in wax of important populations of microorganisms.

  19. Continuing Climate Warming Will Result in Failure of Post-Harvest Natural Regeneration across the Landscape in Interior Alaska

    Science.gov (United States)

    Morimoto, M.; Juday, G. P.; Huettmann, F.

    2016-12-01

    Following forest disturbance, the stand initiation stage decisively influences future forest structure. Understanding post-harvest regeneration, especially under climate change, is essential to predicting future carbon stores in this extensive forest biome. We apply IPCC B1, A1B, and A2 climate scenarios to generate plausible future forest conditions under different management. We recorded presence of white spruce, birch, and aspen in 726 plots on 30 state forest white spruce harvest units. We built spatially explicit models and scenarios of species presence/absence using TreeNet (Stochastic Gradient Boosting). Post-harvest tree regeneration predictions in calibration data closely matched the validation set, indicating tree regeneration scenarios are reliable. Early stage post-harvest regeneration is similar to post-fire regeneration and matches the pattern of long-term natural vegetation distribution, confirming that site environmental factors are more important than management practices. Post-harvest natural regeneration of tree species increases under moderate warming scenarios, but fails under strong warming scenarios in landscape positions with high temperatures and low precipitation. Under all warming scenarios, the most successful regenerating species following white spruce harvest is white spruce. Birch experiences about 30% regeneration failure under A2 scenario by 2050. White spruce and aspen are projected to regenerate more successfully when site preparation is applied. Although white spruce has been the major managed species, birch may require more intensive management. Sites likely to experience regeneration failure of current tree species apparently will experience biome shift, although adaptive migration of existing or new species might be an option. Our scenario modeling tool allows resource managers to forecast tree regeneration on productive managed sites that have made a disproportionate contribution to carbon flux in a critical region.

  20. Human pathogen avoidance adaptations

    NARCIS (Netherlands)

    Tybur, J.M.; Lieberman, D.

    2016-01-01

    Over the past few decades, researchers have become increasingly interested in the adaptations guiding the avoidance of disease-causing organisms. Here we discuss the latest developments in this area, including a recently developed information-processing model of the adaptations underlying pathogen

  1. Post-storage cell wall metabolism in two sweet cherry (Prunus avium L.) cultivars displaying different postharvest performance.

    Science.gov (United States)

    Belge, Burcu; Comabella, Eva; Graell, Jordi; Lara, Isabel

    2015-09-01

    The biochemical processes underlying firmness loss of sweet cherry (Prunus avium L.) fruit are poorly understood. Studies on cell wall metabolism of sweet cherry have been generally undertaken during on-tree development or at harvest maturity, while published reports on postharvest changes are scarce and fragmentary. In this work, cell wall modifications after storage at 0 ℃ were studied in two cherry cultivars ('Celeste' and 'Somerset') displaying different postharvest potential. Firmness was largely determined by the yields of the Na2CO3- and KOH-soluble fractions, enriched in covalently-bound pectins and in matrix glycans, respectively, and correlated well with ascorbic acid contents. The yields of these two cell wall fractions were correlated inversely with pectinmethylesterase and endo-1,4-β-d-glucanase activities, indicating a relevant role of these two enzymes in postharvest firmness changes in sweet cherry. The amount of solubilised cell wall materials was closely associated to the contents of dehydroascorbic acid, suggesting the possible involvement of oxidative mechanisms in cell wall disassembly. These data may help understanding the evolution of fruit quality during the marketing period, and give hints for the design of suitable management strategies to preserve key attributes. © The Author(s) 2014.

  2. Effect of postharvest ultraviolet-C treatment on the proteome changes in fresh cut mango (Mangifera indica L. cv. Chokanan).

    Science.gov (United States)

    George, Dominic Soloman; Razali, Zuliana; Santhirasegaram, Vicknesha; Somasundram, Chandran

    2016-06-01

    Postharvest treatments of fruits using techniques such as ultraviolet-C have been linked with maintenance of the fruit quality as well as shelf-life extension. However, the effects of this treatment on the quality of fruits on a proteomic level remain unclear. This study was conducted in order to understand the response of mango fruit to postharvest UV-C irradiation. Approximately 380 reproducible spots were detected following two-dimensional gel electrophoresis. Through gel analysis, 24 spots were observed to be differentially expressed in UV-C treated fruits and 20 were successfully identified via LCMS/MS. Postharvest UV-C treatment resulted in degradative effects on these identified proteins of which 40% were related to stress response, 45% to energy and metabolism and 15% to ripening and senescence. In addition, quality and shelf-life analysis of control and irradiated mangoes was evaluated. UV-C was found to be successful in retention of quality and extension of shelf-life up to 15 days. Furthermore, UV-C was also successful in increasing antioxidants (total flavonoid, reducing power and ABTS scavenging activity) in mangoes. This study provides an overview of the effects of UV-C treatment on the quality of mango on a proteomic level as well as the potential of this treatment in shelf-life extension of fresh-cut fruits. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  3. Biochemical and proteomic analysis of grape berries (Vitis labruscana) during cold storage upon postharvest salicylic acid treatment.

    Science.gov (United States)

    Cai, Han; Yuan, Xiaozhuan; Pan, Jiaojiao; Li, Huan; Wu, Ziming; Wang, Yun

    2014-10-15

    Salicylic acid (SA) treatment has been widely used to maintain fruit quality during postharvest storage. To elucidate the molecular mechanism related to this treatment, the effect of SA treatment on fruit quality as well as protein expression profiles of grape berries (Vitis labruscana cv. Kyoho) during the subsequent cold storage was evaluated. As expected, SA treatment inhibited postharvest loss and chilling damage by reducing fruit softening and membrane damage and slowing weight loss. A gel-based proteomic approach was designed to screen for differentially expressed proteins in SA-treated and control grape berries. A total of 69 differentially accumulated proteins were successfully identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, which can be functionally classified into eight categories. Among these proteins, antioxidant enzymes including ascorbate peroxidase, oxidoreductase, and glutathione S-transferase were induced, and the abundances of several defense-related proteins, such as heat shock protein (HSP) and temperature-induced lipocalin, were up-regulated by SA treatment. In addition, proteins involved in carbohydrate catabolism and energy production were also induced by SA treatment. Interpretation of the data for differential accumulation of proteins revealed that the effect of SA on reducing postharvest losses and chilling damage of grape berries during cold storage may be due to activated defense responses and carbohydrate metabolism and higher levels of energy status.

  4. Effect of time of day for harvest and postharvest treatments on the sugar metabolism of broccoli (Brassica oleracea var. italica

    Directory of Open Access Journals (Sweden)

    Joaquin Hasperue

    2014-02-01

    Full Text Available     Loss of sugars contributes to accelerate postharvest senescence of broccoli. Several treatments have been developed to delay senescence, but in many cases their effects on sugar metabolism were not analyzed. We studied the effect of harvest at different times of day (08:00, 13:00 and 18:00 h and of several postharvest treatments as heat treatment (HT, modified atmosphere (MA and 1-methylcylcopropene (1-MCP on sugar levels and activities of enzymes related to sucrose and starch degradation. Harvesting at the end of day delayed the loss of chlorophylls and caused the lowest decrement in sugars, although no differences in invertase, sucrose synthase and β-amylase activities were detected among samples. Treatments of MA and 1-MCP caused a lower loss of glucose and fructose, while HT caused a lower decrement of sucrose. Treated samples maintained higher levels of chlorophylls. The treatments reduced the activity of invertase and sucrose synthase and induced higher levels of β-amylase activity. Harvesting at the end of day and performing simultaneously a MA treatment could be a good combination to maintain the green color of the inflorescence and sugar levels during postharvest of broccoli.

  5. Effects of postharvest salicylic acid dipping on Alternaria rot and disease resistance of jujube fruit during storage.

    Science.gov (United States)

    Cao, Jiankang; Yan, Jiaqi; Zhao, Yumei; Jiang, Weibo

    2013-10-01

    Considerable postharvest losses caused by Alternaria alternata often occur in Chinese jujube fruit, and synthetic fungicides have been widely used to protect the fruit from Alternaria rot. However, the potential harmfulness of fungicide residues to human health and the environment cannot be ignored. This study was conducted to develop an alternative approach for controlling postharvest disease by inducing fruit resistance with salicylic acid (SA) dipping. Disease incidence and lesion area in the jujube fruit inoculated with A. alternata were significantly inhibited by 2 and 2.5 mmol L(-1) SA dipping. Naturally infected decay rate and index in jujubes were also significantly reduced by SA dipping during long-term storage at 0°C. SA enhanced activities of the main defense-related enzymes including phenylalanine ammonia-lyase, peroxidase, chitinase and β-1,3-glucanase in the fruit during storage. SA strongly decreased catalase activity but increased superoxide dismutase activity and ascorbic acid content in jujubes. The beneficial effects of SA on fruit protection may be due to its ability to activate several highly coordinated defence-related systems in jujubes, instead of its fungicidal activity. The findings indicated that application of SA would offer an alternative approach that helps to control postharvest disease and maintain storage quality in fruits. © 2013 Society of Chemical Industry.

  6. Postharvest behavior of tamarillo (Solanum betaceum Cav. treated with CaCl2 under different storage temperatures

    Directory of Open Access Journals (Sweden)

    Lida Paola Pinzón-Gómez

    2014-08-01

    Full Text Available The tamarillo, or tree tomato, produced in Colombia, has great potential for commercialization in the global market for tropical exotic fruits, but suffers quality losses during the postharvest phase due to the use of inappropriate technologies. In order to extend the postharvest life of these fruits, the effect of calcium chloride (CaCl2 and different storage temperatures was evaluated. A completely randomized design was used, where the block criterion was the temperature with three treatments (control and calcium chloride doses of 570 and 862 mM and three blocks (6, 9°C and ambient temperature [20°C], for a total of nine experimental treatments monitored every five days for 20 days. The CaCl2 treatments delayed softening over time, as compared to the control but did not affect the other quality attributes. Generally, the fruits stored at low temperatures lost less fresh weight and had a lower respiration rate as compared with the fruits stored at the ambient temperature. During the postharvest, it was observed that the fruits had a pH between 3.84 and 4.36, total acidity between 0.57 and 1.6% and 9.79°Brix on average. The physicochemical properties of the tamarillo were more affected by the ambient temperature than by the application of CaCl2. The temperature of 9°C is recommended for maintaining the quality of this fruit for 20 days.

  7. Effect of ethylene and 1-methylcyclopropene on the postharvest behavior of cape gooseberry fruits (Physalis peruviana L.).

    Science.gov (United States)

    Balaguera-López, Helber E; Espinal-Ruiz, Mauricio; Zacarías, Lorenzo; Herrera, Aníbal O

    2017-01-01

    Cape gooseberry (Physalis peruviana L.) fruits are highly perishable berries that exhibit a climacteric respiratory behavior. The objective of this study was to evaluate the effect of ethylene and the ethylene action inhibitor 1-methylcyclopropene on the postharvest behavior of cape gooseberry fruits (ecotype Colombia). Fruits were treated with ethylene, in an ethephon application (1000 µL L -1 ), and pretreated with 1-methylcyclopropene (1 µL L -1 ), 1-methylcyclopropene+ethylene, and results compared with a control without application. Subsequently, the fruits were maintained at room temperature (20 ℃, 75% RH) for up to 11 days. The pretreatment of the cape gooseberry fruits with 1-methylcyclopropene delayed most of the ripening-associated parameters, with a reduction in the respiration rate and ethylene production, skin color development, total soluble solids, total carotenoid content, loss of firmness, loss of total titratable acidity and emission of volatile compounds such as ethyl octanoate, ethyl butanoate, ethyl decanoate, and hexyl decanoate. Conversely, application of ethephon accelerated most of these physiological changes and also overcame most of the effects prevented by the ethylene action inhibitor. Altogether, the results supported the idea of a climacteric-like behavior for cape gooseberry fruits and pointing out that the pretreatment with 1-methylcyclopropene may be a promising and efficient postharvest treatment to delay maturity and extend the postharvest period. © The Author(s) 2016.

  8. Viabilidade do inoculante turfoso produzido com bactérias associativas e molibdênio Viability of peat inoculum produced with associative bacteria and molybdenum

    Directory of Open Access Journals (Sweden)

    Salomão Lima Guimarães

    2013-03-01

    Full Text Available Dentre os veículos de inoculação de bactérias diazotróficas, o turfoso é considerado o mais utilizado no Brasil. A turfa possibilita a viabilidade de um grande número de células, protegendo-as também das adversidades do solo. O objetivo deste trabalho foi avaliar a viabilidade do inoculante turfoso desenvolvido com bactérias diazotróficas associativas e molibdênio. As bactérias BR11417 (Herbaspirillum seropedicae e BR11340 (Burkholderia sp., foram multiplicadas por um período de 24 horas e uma alíquota de 10 mL com 10(8 cel. mL-1 foi transferida para sacos de polipropileno contendo 35 g de turfa. Foram adicionadas duas doses e duas fontes de molibdênio: 1,12 e 2,25 g de molibdato de sódio e de amônio, respectivamente. Como controle, foi utilizado o inoculante sem molibdênio. A legislação brasileira, por meio da lei n° 86955, especifica que os inoculantes comerciais à base de micro-organismos fixadores de nitrogênio apresentem concentrações mínimas de 10(8 células viáveis por grama do produto no momento do uso e que a viabilidade das células seja mantida por um período mínimo de seis meses. Este estudo mostrou que sem a adição do molibdênio ao inoculante, as bactérias sobreviveram com um número de células viáveis em torno de 10(8 células g-1 de inoculante, por um período de até 110 dias. Com a adição do molibdênio, o inoculante manteve-se viável por um período de 180 dias. A aplicação do molibdênio contribui para o aumento da viabilidade do inoculante turfoso produzido com as estirpes BR11417 e BR11340.Among the vehicles in use for diazotroph inoculation, peat is considered the most-widely used in Brazil. Peat makes possible the viability of a large number of cells, at the same time protecting them from adversities found in the soil. The objective of this study was to evaluate the viability of peat inoculum developed with diazotroph bacteria and molybdenum. The bacteria BR11417 (Herbaspirillum

  9. Efficacy of Ceftaroline against Methicillin-Susceptible Staphylococcus aureus Exhibiting the Cefazolin High-Inoculum Effect in a Rat Model of Endocarditis

    Science.gov (United States)

    Tran, Truc T.; Nannini, Esteban C.; Tam, Vincent H.; Arias, Cesar A.; Murray, Barbara E.

    2017-01-01

    ABSTRACT Certain Staphylococcus aureus strains exhibit an inoculum effect (InE) with cefazolin (CFZ) that has been associated with therapeutic failures in high-inoculum infections. We assessed the in vitro activities of ceftaroline (CPT), CFZ, and nafcillin (NAF) against 17 type A β-lactamase (βla)-producing, methicillin-susceptible S. aureus (MSSA) strains, including the previously reported TX0117, which exhibits the CFZ InE, and its βla-cured derivative, TX0117c. Additionally, we determined the pharmacokinetics of CPT in rats after single intramuscular doses of 20 and 40 mg/kg of body weight and evaluated the activities of CPT (40 mg/kg every 8 h [q8h]), CFZ, and NAF against TX0117 and TX0117c in a rat model of infective endocarditis. No InE was observed for CPT or NAF, whereas a marked InE was detected for CFZ (MIC, 8 to ≥128 μg/ml). CPT and NAF treatment against TX0117 resulted in mean bacterial counts of 2.3 and 2.1 log10 CFU/g in vegetations, respectively, compared to a mean of 5.9 log10 CFU/g in the CFZ-treated group (CPT and NAF versus CFZ, P = 0.001; CPT versus NAF, P = 0.9830). Both CFZ and CPT were efficacious against the βla-cured derivative, TX0117c, compared to time zero (t0) (P = <0.0001 and 0.0015, respectively). Our data reiterate the in vivo consequences of the CFZ InE and show that CPT is not affected by this phenomenon. CPT might be considered for high-inoculum infections caused by MSSA exhibiting the CFZ InE. PMID:28483961

  10. Efficacy of Ceftaroline against Methicillin-Susceptible Staphylococcus aureus Exhibiting the Cefazolin High-Inoculum Effect in a Rat Model of Endocarditis.

    Science.gov (United States)

    Singh, Kavindra V; Tran, Truc T; Nannini, Esteban C; Tam, Vincent H; Arias, Cesar A; Murray, Barbara E

    2017-07-01

    Certain Staphylococcus aureus strains exhibit an inoculum effect (InE) with cefazolin (CFZ) that has been associated with therapeutic failures in high-inoculum infections. We assessed the i n vitro activities of ceftaroline (CPT), CFZ, and nafcillin (NAF) against 17 type A β-lactamase (βla)-producing, methicillin-susceptible S. aureus (MSSA) strains, including the previously reported TX0117, which exhibits the CFZ InE, and its βla-cured derivative, TX0117c. Additionally, we determined the pharmacokinetics of CPT in rats after single intramuscular doses of 20 and 40 mg/kg of body weight and evaluated the activities of CPT (40 mg/kg every 8 h [q8h]), CFZ, and NAF against TX0117 and TX0117c in a rat model of infective endocarditis. No InE was observed for CPT or NAF, whereas a marked InE was detected for CFZ (MIC, 8 to ≥128 μg/ml). CPT and NAF treatment against TX0117 resulted in mean bacterial counts of 2.3 and 2.1 log 10 CFU/g in vegetations, respectively, compared to a mean of 5.9 log 10 CFU/g in the CFZ-treated group (CPT and NAF versus CFZ, P = 0.001; CPT versus NAF, P = 0.9830). Both CFZ and CPT were efficacious against the βla-cured derivative, TX0117c, compared to time zero ( t 0 ) ( P = InE and show that CPT is not affected by this phenomenon. CPT might be considered for high-inoculum infections caused by MSSA exhibiting the CFZ InE. Copyright © 2017 American Society for Microbiology.

  11. Autophagy in plant pathogenic fungi.

    Science.gov (United States)

    Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

    2016-09-01

    Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Temperature Effect Study on Growth and Survival of Pathogenic Vibrio parahaemolyticus in Jinjiang Oyster (Crassostrea rivularis with Rapid Count Method

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    2018-01-01

    Full Text Available The growth of Vibrio parahaemolyticus (V. parahaemolyticus in oysters during postharvest storage increases the possibility of its infection in humans. In this work, to investigate the growth or survival profiles in different media, pathogenic V. parahaemolyticus in APW, Jinjiang oyster (JO, Crassostrea rivularis slurry, and live JO were studied under different temperatures. All the strain populations were counted through our double-layer agar plate (DLAP method. In APW, the pathogenic V. parahaemolyticus showed continuous growth under 15, 25, and 35°C, while a decline in behavior was displayed under 5°C. The similar survival trend of pathogenic V. parahaemolyticus in JO slurry and live JO was observed under 5, 25, and 35°C, except the delayed growth or decline profile compared to APW. Under 15°C, they displayed decline and growth profile in JO slurry and live JO, respectively. These results indicate the different sensitivity of pathogenic V. parahaemolyticus in these matrices to temperature variation. Furthermore, nonpathogenic V. parahaemolyticus displayed little difference in survival profiles when inoculated in live JO under corresponding temperatures. The results indicate that inhibition or promotion effect could be regulated under different storage temperature for both pathogenic and nonpathogenic strains. Besides, the DLAP method showed the obvious quickness and efficiency during the bacteria count.

  13. Evolution of microbial pathogens.

    OpenAIRE

    Morschhäuser, J; Köhler, G; Ziebuhr, W; Blum-Oehler, G; Dobrindt, U; Hacker, J

    2000-01-01

    Various genetic mechanisms including point mutations, genetic rearrangements and lateral gene transfer processes contribute to the evolution of microbes. Long-term processes leading to the development of new species or subspecies are termed macroevolution, and short-term developments, which occur during days or weeks, are considered as microevolution. Both processes, macro- and microevolution need horizontal gene transfer, which is particularly important for the development of pathogenic micr...

  14. Pathogenic characterization of lasiodplodia causing stem end rot of mango and its control using botanicals

    International Nuclear Information System (INIS)

    Ullah, S. F.; Hussain, Y.; Iram, S.

    2017-01-01

    Two widely cultivated mango fruit varieties White chounsa and Sindhri were collected from two major mango growing areas of Punjab and Sindh Provinces of Pakistan. This study was focused on pathological characterization of predominant postharvest diseases such as stem end rot of mango (Mangifera indica) caused by Lasiodiplodia theobromae, and evaluation of bio-control activity by different plant extracts. L. theobromae aggressiveness of isolates was tested by artificial inoculations under controlled conditions, all isolates proved pathogenic in varying degree of aggressiveness on (Sindhri and White chounsa) with reference to control. Calculated standard error mean varied in lesion area produced by pathogens 6-63cm/sup 2/ (Sindhri) and 60-170 cm/sup 2/ (White chounsa). Re-isolation of respective fungi verified the Koch's postulates. Plant extract of Datura stramonium, Aloe-vera, Eucalyptus camaldulensis, were used to control the radial growth of L. theobromae. Comparative analysis showed D. Stramonium and E. camaldulensis extracts most efficiently reduced the growth of Lasiodiplodia isolates, in comparison to Aloe-vera extract, restrict the 15-20% growth. All pathological results and treatments were significant at p<0.05 through ANOVA. This study emphasizes the behavior of pathogens which could be helpful in mango breeding to introduce resistance toward Lasiodiplodia and referred plants provide the best alternative of chemical fungicides. (author)

  15. Metabolites produced by antagonistic microbes inhibit the principal avocado pathogens in vitro

    Directory of Open Access Journals (Sweden)

    Sara Ramírez R.

    2015-04-01

    Full Text Available The demand for Hass avocado in the global market exceeds the supply by over 50%. Colombia has a remarkable advantage as a producer in the region due to its high yields. However, the productivity of this crop can be seriously affected by diseases such as root rot, caused by Phytophthora cinnamomi, postharvest body rot and stem end rot, caused by Colletotrichum sp. and Phomopsis sp., respectively. The potential of 76 bacterial isolates obtained from avocado rhizosphere to produce inhibitory metabolites against avocado's pathogens was evaluated. The antagonistic effect of the rhizobacteria against P. cinnamomi, Colletotrichum sp. and Phomopsis sp. was tested through dual cultures. Thirty-six percent of the tested isolates presented inhibition halos against P. cinnamomi, 36% against Colletotrichum sp. and 67% against Phomopsis sp. Additionally, three isolates were selected for fermentation tests using different broth cultures. The extracts obtained from fermentations in the minimal medium of isolates ARP5.1 and AED06 showed inhibitory activity against the evaluated pathogens, but this effect was not observed with the AED26 extract. The media supplemented with copper chloride did not enhance activity of the extracts. These results suggest that using microbial metabolic extracts is a viable alternative for controlling avocado pathogens in vitro.

  16. Effects of Inoculum Amount, Initial pH, and Nicotine Load on the Set-Up of Bioaugmented System with Pseudomonas Sp. HF-1 to Treat Tobacco Wastewater

    Directory of Open Access Journals (Sweden)

    Kun Zhang

    2014-01-01

    Full Text Available This study evaluated and optimized the influence of inoculum amount, initial pH, and nicotine load on the construction of Pseudomonas sp. HF-1 bioaugmented system for tobacco wastewater treatment. The results demonstrated that the optimum condition for the set-up of strain HF-1 bioaugmented system was 1.10 mg/g (dry weight of strain HF-1/dry weight of activated sludge of inoculum amount, initial pH 7.0, and 250–1000 mg/L nicotine load. Higher than 1.10 mg/g could lead to noncolonization of strain HF-1 in activated sludge and failure of set-up of this bioaugmented system. Higher than pH 8.0 could restrain the colonization of strain HF-1 in activated sludge. Even though strain HF-1 colonizes in the activated sludge when pH was above 8.0, the removal of nicotine and total organic carbon (TOC was suppressed due to low activities of bacteria in the activated sludge. Nicotine load did not show inhibition effect on set-up of bioaugmented system, but the ability of TOC removal was restrained when the nicotine load was above 1000 mg/L. This work could offer vital parameters for the set-up of bioaugmented system to treat tobacco wastewater in engineering.

  17. The influence of Aspergillus niger inoculum dosage on nutritive value and metabolizable energy of apu-apu meal (Pistia stratiotes L.) on broiler chicken

    Science.gov (United States)

    Gloria, J.; Tafsin, M.; Hanafi, N. D.; Daulay, A. H.

    2018-02-01

    Apu-apu lives at tropical and subtropical fresh waterways. The apu-apu meals ultization as feed still limited. The problem of ultization apu-apu meals as ingredients is a high crude fiber and need a treatment to decrease crude fiber. This study aim to find out the influence of Aspergillus niger inoculums dosage on apu-apu meal (Pistia stratiotes L.) on metabolizable energy on broiler chicken. This research used completely randomize design (CRD). The treatments consists of Aspergillus niger inoculum dosage (CFU/g) such as P0 (0), P1 (104 CFU/g), P2 (106 CFU/g), and P3 (108 CFU/g). The variable were observed : apparent metabolizable energy (AME), true metabolizable energy (TME), apparent metabolizable energy nitrogen corrected (AMEn) and true metabolizable energy nitrogen corrected (TMEn).The results showed that the dosage of Aspergillus niger increase nutritive value of Aspergillus niger. Dosage of Aspergillus niger also influence (P<0.05) metabolizable energy of apu-apu meals. Dosage 108 CFU/g had metabolizable energy significantly higher than other treatments. Conclusion of this research is the Aspergillus niger at the dosage 108 CFU/g increased nutritive value and metabolizable energy of apu-apu meal.

  18. The influence of inoculum composition on selected bioactive and nutritional parameters of grass pea tempeh obtained by mixed-culture fermentation with Rhizopus oligosporus and Aspergillus oryzae strains.

    Science.gov (United States)

    Starzynska-Janiszewska, A; Stodolak, B; Dulinski, R; Mickowska, B

    2012-04-01

    Tempeh is a popular Indonesian product obtained from legume seeds by solid-state fermentation with Rhizopus sp. The aim of this research was to study the effect of simultaneous mixed-culture fermentation of grass pea seeds on selected parameters of products as compared to traditional tempeh. The inoculum contained different ratios of Rhizopus oligosporus and Aspergillus oryzae spores. The simultaneous fermentation of grass pea seeds with inoculum consisting of 1.2 × 10(6) R. oligosporus and 0.6 × 10(6) A. oryzae spores (per 60 g of seeds) resulted in a product of improved quality, as compared with traditionally made tempeh (obtained after inoculation with 1.2 × 10(6) R. oligosporus spores), at the same fermentation time. This product had radical scavenging ability 70% higher than the one obtained with pure R. oligosporus culture and contained 2.23 g/kg dm of soluble phenols. The thiamin and riboflavin levels were above three (340 µg/g dm) and two (50.50 µg/g dm) folds higher than in traditionally made tempeh, respectively. The product had 65% in vitro bioavailability of proteins and 33% in vitro bioavailability of sugars. It also contained 40% less 3-N-oxalyl-L-2, 3-diaminopropionic acid (0.074 g/kg dm), as compared to traditional tempeh.

  19. Chitosan Coating: A Postharvest Treatment to Delay Oxidative Stress in Loquat Fruits during Cold Storage

    Directory of Open Access Journals (Sweden)

    Giuseppina Adiletta

    2018-04-01

    Full Text Available Loquat is a non-climacteric fruit consumed fresh for its essential nutrients and phytochemical compounds. In this study, the effects of chitosan coating (1% w/v on changes in the enzymatic antioxidant and membrane damage in three loquat selections (CREAFRC-S18; CREAFRC-S35 and CREAFRC-S36 and three loquat cultivars (Golden Nugget, Algerie and Nespolone rosso di Trabia stored at 7 °C over 21 days were evaluated. Chitosan treatment enhanced the activities of superoxide dismutase, catalase and ascorbate peroxidase. Moreover, this treatment inhibited polyphenol oxidase and guaiacol peroxidase activities, extending the storage life of loquat. Chitosan also preserved membrane integrity by inhibiting lipoxygenase activity and malondialdehyde accumulation. Principal component analysis provided a global view of the responses of both loquat selections and cultivars to the postharvest chitosan coating and storage temperature. These findings suggest that chitosan treatment could be a valid tool for improving the activity of antioxidant enzymes, preserving the enzymatic browning of loquat fruits.

  20. Effect of controlled atmosphere on postharvest quality of 'Douradão' peaches

    Directory of Open Access Journals (Sweden)

    Ligia Regina Radomille de Santana

    2011-03-01

    Full Text Available This study was carried out with one of the most important cultivar grown in the State of Sao Paulo, Brazil, which has gained the preference of consumers, due to its sweet taste, intense skin color and large size; however, these fruits are susceptible to chilling injury when cold stored for long periods. The use of controlled atmosphere (CA with elevated CO2 and reduced O2 concentrations prevent the onset of the chilling symptom. Thus, the effect of three different conditions of controlled atmosphere (CA1, CA2, CA3 and Control was evaluated in order to extend the storage life of 'Douradão' peaches. After 14, 21 and 28 days, samples were withdrawn from CA and kept in fresh air at 25 ± 1 °C and 90 ± 5% RH to complete ripening. On the day of removal and after 4 days, were the peaches quality characteristics were evaluated. The results showed that the use of CA during cold storage reduced weight loss and prevented postharvest decay. CA2 and CA3 treatments were effective in keeping good quality of 'Douradão' peaches during 28 days of cold storage, the ripe fruits showed reduced incidence of woolliness, adequate juiciness and flesh firmness. CA1 and Control treatments did not present marketable conditions after 14 days of cold storage.

  1. In Vitro Control of Post-Harvest Fruit Rot Fungi by Some Plant Essential Oil Components

    Directory of Open Access Journals (Sweden)

    Gian Luigi Rana

    2012-02-01

    Full Text Available Eight substances that are main components of the essential oils from three Mediterranean aromatic plants (Verbena officinalis, Thymus vulgaris and Origanum vulgare, previously found active against some phytopathogenic Fungi and Stramenopila, have been tested in vitro against five etiological agents of post-harvest fruit decay, Botrytis cinerea, Penicillium italicum, P. expansum, Phytophthora citrophthora and Rhizopus stolonifer. The tested compounds were β-fellandrene, β-pinene, camphene, carvacrol, citral, o-cymene, γ-terpinene and thymol. Citral exhibited a fungicidal action against P. citrophthora; carvacrol and thymol showed a fungistatic activity against P. citrophthora and R. stolonifer. Citral and carvacrol at 250 ppm, and thymol at 150 and 250 ppm stopped the growth of B. cinerea. Moreover, thymol showed fungistatic and fungicidal action against P. italicum. Finally, the mycelium growth of P. expansum was inhibited in the presence of 250 ppm of thymol and carvacrol. These results represent an important step toward the goal to use some essential oils or their components as natural preservatives for fruits and foodstuffs, due to their safety for consumer healthy and positive effect on shelf life extension of agricultural fresh products.

  2. Preservation of Postharvest Quality of Leafy Amaranth (Amaranthus spp. Vegetables Using Evaporative Cooling

    Directory of Open Access Journals (Sweden)

    Jane Ambuko

    2017-01-01

    Full Text Available Leafy vegetables are very highly perishable and must be utilized immediately after harvest. Their fast deterioration is attributed to various biological and environmental factors with temperature playing a central role. Evaporative cooling is a low-cost temporary storage technology that offers smallholder vegetable farmers an alternative to expensive cold rooms. The present study sought to determine the effectiveness of evaporative cooling using zero energy brick cooler (ZEBC and evaporative charcoal cooler (ECC, to preserve the postharvest quality of leafy amaranth vegetables. Freshly harvested vegetables were separated into bundles weighing 300 grams and stored under ZEBC, ECC, and ambient room conditions (control. Real time changes in temperature and relative humidity (RH as well as changes in quality attributes (physiological weight loss (PWL, wilting index, hue angle, and vitamin C were determined during the storage period. The temperature difference between the ZEBC and ECC versus the ambient air ranged between 4 and 10°C. Significantly higher RH (80–100% was recorded in both evaporative cooling chambers. At the end of storage, higher PWL (47.6% was recorded at ambient room conditions compared to 10.5 and 6.7% under ZEBC and ECC, respectively. A rapid decline in vitamin C (51% was reported in vegetables stored at ambient room conditions. Overall, there was better vegetable quality preservation under ECC and ZEBC.

  3. Effect of main stem pruning and fruit thinning on the postharvest conservation of melon

    Directory of Open Access Journals (Sweden)

    Rafaella M. de A. Ferreira

    Full Text Available ABSTRACT Main stem pruning and fruit thinning are cultivation practices that can influence the yield and quality of the fruit. This study aimed to evaluate the effects of main stem pruning and fruit thinning on the postharvest conservation of Charentais Banzai melons. In the field, the plants were subjected to main stem pruning and fruit thinning, with harvesting done 74 days after sowing (DAS. The fruits were transported to the laboratory where they were cleaned, characterized, and stored in a cold chamber (5 °C and 90 ± 2% RH. In the field, the experiment was designed as a split-plot using a 2 × 4 + 1 factorial design, with two levels of main stem pruning (pruned and unpruned, four levels of thinning times (42, 45, 48, and 51 DAS, and a control (unpruned and unthinned. The sub-plot consisted of storage times (0, 7, 14, 21, and 28 days, with four blocks. The preharvest treatments did not significantly influence the production characteristics of the Banzai hybrid. The treatment without pruning increased the titratable acidity of fruit, and the thinning at 51 days after sowing (DAS reduced soluble sugars. There was a decline in pulp firmness, titratable acidity, reducing sugars, and an increase in soluble solids, total soluble sugar, and non-reducing sugars during storage. Pruning the main melon stem reduced the weight loss of the fruit after 28 days of storage.

  4. Food and nutrition security: challenges of post-harvest handling in Kenya.

    Science.gov (United States)

    Kimiywe, J

    2015-11-01

    Presently, close to 1 billion people suffer from hunger and food insecurity. Statistics in Kenya indicates that over 10 million people suffer from chronic food insecurity and poor nutrition, 2-4 million people require emergency food assistance at any given time with nearly 30 % of Kenya's children being undernourished, 35 % stunted while micro-nutrient deficiency is wide spread. Key among the challenges contributing to inadequate foods include lack of certified seeds, seasonal production (rain-fed), high post-harvest losses and wastages, poor transportation, low value additions which reduce their market competitiveness. The present paper examines some of the underlying causes for high food wastage experience in Kenya and the associated challenges in addressing these problems. The paper also provides an overview of some of the basic solutions that have been recommended by various stakeholders. However, in spite of the recent efforts made to mitigate food wastage, there is still an urgent need to address these gaps through participatory, innovative community based interventions that will create resilience to climate change and enhance livelihoods of smallholder farmers in diverse ecosystems.

  5. Study of Post-Harvest Ambon Banana ( Musa acuminata ) Preservation Using X-Ray

    International Nuclear Information System (INIS)

    Dwijananti, P.; Handayani, L.; Marwoto, P.; Iswari, R.S.

    2016-01-01

    An exposure to Ambon banana ( Musa Acuminata ) samples has been done by using X-rays with current, voltage and exposure time are control parameters. This study aimed to determine storage ability of the post-harvest sample. Five samples were exposured by x-rays with the dose of (3-5) × 10 -14 Gy. The samples were stored at room temperature. Their mass and physical condition (color and smell) were evaluated every 3 days. It was found that the control sample which was not exposured by X-ray was ripe in the sixth day indicated by the yellow color and good smell of the banana. Meanwhile, the samples which were exposured by (3 - 5) × 10 -14 Gy doze of X-ray looked fresher and still had green color. These samples showed their ripening in the ninth day and their mass decrease was (12-13)% which is lower than the control sample. The preservation of banana can be done through low-dose X-ray exposure. (paper)

  6. Effect of LED irradiation on the ripening and nutritional quality of postharvest banana fruit.

    Science.gov (United States)

    Huang, Jen-Yi; Xu, Fengying; Zhou, Weibiao

    2018-04-24

    With the ability to tailor wavelengths necessary to the photosynthetically active radiation spectrum of plant pigments, light-emitting diodes (LEDs) offer vast possibilities in horticultural lighting. The influence of LED light irradiation on major postharvest features of banana was investigated. Mature green bananas were treated daily with selected blue (464-474 nm), green (515-525 nm) and red (617-627 nm) LED lights for 8 days, and compared with non-illuminated control. The positive effect of LED lighting on the acceleration of ripening in bananas was greatest for blue, followed by red and green. Under the irradiation of LED lights, faster peel de-greening and flesh softening, and increased ethylene production and respiration rate in bananas were observed during storage. Furthermore, the accumulations of ascorbic acid, total phenols, and total sugars in banana fruit were enhanced by LED light exposure. LED light treatment can induce the ripening of bananas and improve their quality and nutrition potential. These findings might provide new chemical-free strategies to shorten the time to ripen banana after harvest by using LED light source. This article is protected by copyright. All rights reserved.

  7. An Overview of the Post-Harvest Grain Storage Practices of Smallholder Farmers in Developing Countries

    Directory of Open Access Journals (Sweden)

    Ashish Manandhar

    2018-04-01

    Full Text Available Grain storage loss is a major contributor to post-harvest losses and is one of the main causes of food insecurity for smallholder farmers in developing countries. Thus, the objective of this review is to assess the conventional and emerging grain storage practices for smallholder farmers in developing countries and highlight their most promising features and drawbacks. Smallholder farmers in developing countries use conventional grain storage structures and handling systems such as woven bags or cribs to store grain. However, they are ineffective against mold and insects already present in the grain before storage. Different chemicals are also mixed with grain to improve grain storability. Hermetic storage systems are effective alternatives for grain storage as they have minimal storage losses without using any chemicals. However, hermetic bags are prone to damage and hermetic metal silos are cost-prohibitive to most smallholder farmers in developing countries. Thus, an ideal grain storage system for smallholder farmers should be hermetically sealable, mechanically durable, and cost-effective compared to the conventional storage options. Such a storage system will help reduce grain storage losses, maintain grain quality and contribute to reducing food insecurity for smallholder farmers in developing countries.

  8. Handling and postharvest shelf life of ora-pro-nobis leaves

    Directory of Open Access Journals (Sweden)

    Camila Karen Reis Barbosa

    2015-08-01

    Full Text Available The goal of this study was to assess the effects of hydrocooling and plastic bag use on the postharvest quality ora-pro-nobis (Pereskia aculeata Mill. leaves stored at 5 and 25ºC. The experiments were conducted in a split plot scheme, with treatments in plots and subplots storage time in a randomized block design. The leaf chlorophyll content, mass loss (ML, relative water content (RWC, soluble sugars levels, reducings (RED, non-reducings and starch were determined. In leaves stored at 25ºC, the ML was higher when leaves were hydrocooled. The highest RWC resulted from the use of plastic bag, which prevented the leaves from wilting for a longer period of time. The soluble sugars levels varied according to the increase or decrease in RWC. The contents of RED decreased with the time of storage at 25°C. The cold storage increased the shelf life of ora-pro-nobis by 168 hours. The hydrocooling increased the RWC of leaves, although it did not influence the shelf life. The perforated plastic bag was effective in increasing the shelf life, and when associated with hydrocooling, the plastic bags provide a lower rate of loss of fresh mass.

  9. Reduction of energy usage in postharvest horticulture through management of ethylene.

    Science.gov (United States)

    Wills, Ron B H; Golding, John B

    2015-05-01

    Cool chain management is the preferred technology to extend the postharvest life of horticultural produce, but with rising energy costs and community pressure to reduce greenhouse gas emissions, there is a need to use less energy-intensive technologies. Minimising the level of ethylene around horticultural produce inhibits ripening and senescence and therefore has the potential to reduce the use of refrigeration. The long-distance transport of bananas within Australia and from Central America to Europe is used as a case study to show that the need for refrigeration could be reduced if the appropriate concentrations of ethylene were maintained around fruit during transit. Data are also presented to show a similar benefit of ethylene control with green beans, as well as another study showing that apples treated with the ethylene action inhibitor 1-methylcyclopropene could be stored at a higher temperature without loss of quality to the consumer. The range of technologies available to manage ethylene levels is discussed. © 2014 Society of Chemical Industry.

  10. Postharvest Chemical, Sensorial and Physical-Mechanical Properties of Wild Apricot (Prunus armeniaca L.

    Directory of Open Access Journals (Sweden)

    Evica MRATINIĆ

    2011-11-01

    Full Text Available Some chemical, sensorial and physical-mechanical properties of 19 apricot genotypes and Hungarian Best (control such as moisture content, soluble solids content, titratable acidity ratio and their ratio, fruit and stone mass, flesh/stone ratio, fruit dimensions (length, width, thickness, arithmetic and geometric mean diameter, sphericity, surface area and aspect ratio were determined. Their application is also discussed. The highest moisture content and stone mass observed in X-1/1/04 and X-1/2/04, soluble solids content in ZO-1/03, titratable acidity in ZL-2/03, SS/TA ratio in ZL-1/03, and fruit mass and flesh/stone ratio in DL-1/1/04 genotype. The most number of genotypes have orange and deep orange skin and flesh colour, respectively, whereas sweet kernel taste was predominant in most genotypes. Regarding physical-mechanical properties, the superior fruit dimensions (length, width, thickness, arithmetic and geometric mean diameter and surface area observed in DL-1/1/04 genotype, whereas the highest sphericity and surface area observed in X-1/1/04 and X-1/2/04 genotypes. Also, the series of genotypes evaluated have better chemical, sensorial and physical-mechanical properties than Hungarian Best (control. Finally, information about these properties is very important for understanding the behaviour of the product during the postharvest operations.

  11. Comparative evaluation of six storage methods for postharvest preservation of cowpea grain

    KAUST Repository

    Baoua, I. B.

    2012-04-01

    Several technologies reputedly minimize losses of stored cowpea grain to bruchid beetles on low resource farms in Africa. Side by side comparison of these different postharvest storage methods can provide the basis for deciding which performs best. We compared six different technologies for cowpea storage: (1) grain mixed with ash; (2) mixed with sand; (3) fumigated with phostoxin; (4) admixed with the stems and leaves of . Boscia senegalensis (Pers) Lam ex Poir, a potential botanical insecticide; (5) disinfested using a solar heater, and; (6) hermetically sealed in triple-layer plastic bags. Sampling was done at thirty-day intervals over five months of storage. Counts were made of (i) adult emergence holes, (ii) dead larvae and (iii) surviving bruchid larvae and adults. Controls, which consisted of infested cowpea grain stored in cloth bags, were damaged extensively. . Boscia senegalensis-treated grain suffered similar severe damage. All other treatments suppressed bruchid population increases as was evident from the much lower counts of emergence holes and lower numbers of surviving or dead insects. © 2012 Elsevier Ltd.

  12. Ozone fumigation for safety and quality of wine grapes in postharvest dehydration.

    Science.gov (United States)

    Botondi, Rinaldo; De Sanctis, Federica; Moscatelli, Niccolò; Vettraino, Anna Maria; Catelli, Cesare; Mencarelli, Fabio

    2015-12-01

    This paper proposes postharvest ozone fumigation (as a method) to control microorganisms and evaluate the effect on polyphenols, anthocyanins, carotenoids and cell wall enzymes during the grape dehydration for wine production. Pignola grapes were ozone-treated (1.5 g/h) for 18 h (A=shock treatment), then dehydrated or ozone-treated (1.5 g/h) for 18 h and at 0.5 g/h for 4 h each day (B=long-term treatment) during dehydration. Treatment and dehydration were performed at 10 °C. No significant difference was found for total carotenoid, total phenolic and total anthocyanin contents after 18 h of O3 treatment. A significant decrease in phenolic and anthocyanin contents occurred during treatment B. Also carotenoids were affected by B ozone treatment. Pectin methylesterase (PME) and polygalacturonase (PG) activities were higher in A-treated grapes during dehydration. Finally, ozone reduced fungi and yeasts by 50%. Shock ozone fumigation (A treatment) before dehydration can be used to reduce the microbial count during dehydration without affecting polyphenol and carotenoid contents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Changes in postharvest quality of Swiss chard grown using 3 organic preharvest treatments.

    Science.gov (United States)

    Daiss, N; Lobo, M G; Gonzalez, M

    2008-08-01

    Using storage conditions recommended for conventional chard (4 degrees C, 90% RH and 7 d), the chard treated with some organic preharvest treatments [effective microorganisms, a fermented mixture of effective microorganisms with organic matter (EM-Bokashi + EM), and an auxiliary soil product] lost considerable water (> 2%) and weight (> 25%). These results indicate that organic methods tested produce a vegetable that can not sustain its quality when commercialized through the conventional supply chain. Nevertheless, respiration, color, pH, and titratable acidity practically remained constant during conservation. Ascorbic acid content was constant in chard treated with the different preharvest treatments and collected at 8 wk after sowing (normal harvest). However, the ascorbic acid content of the control chard decreased 60% after 7 d of storage. This vitamin diminished (35%) in chard collected after 19 wk after sowing (late harvest) during the postharvest conservation. The greatest difference in chard quality was registered between sampling dates since chard collected during the late harvest had higher levels of dry matter, sugars, acids, proteins, and ascorbic acid than chard collected during the normal harvest.

  14. Effect of salicylic acid treatment on postharvest quality, antioxidant activities, and free polyamines of asparagus.

    Science.gov (United States)

    Wei, Yunxiao; Liu, Zhenfeng; Su, Yujing; Liu, Donghong; Ye, Xingqian

    2011-03-01

    The effects of salicylic acid (SA) on the quality and antioxidant activity of asparagus stored at 18 ± 2 °C were investigated by analyzing the color, chlorophyll, shear force, and the activity of antioxidant compounds such as ascorbic acid, phenolics, flavonoids, 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity ferric reducing antioxidant power (FRAP), and polyamines (PAs). The results showed that SA improved the color and maintained the chlorophyll, phenolic, flavonoid, and ascorbic acid content of asparagus. High concentrations of SA caused a deterioration in asparagus would harm to color and had no effect on shear force within 6 d. SA induced the maximum concentration of phenolics in postharvest asparagus, promoted the increase in total flavonoids before 6 to 9 d, affected the antioxidant activity positively as indicated by the resultant increase in FRAP concentration; however, SA was only active with regard to DPPH scavenging activity within 6 d of treatment. Spermidine (Spd) is the most common form of PA in asparagus, and free putrescine (Put) contents increased over the first 3 d following harvest and then decreased. Spd and Spm concentrations evolved in a similar way and decreased during storage. Higher Spd and Spm contents in the SA pre-treatment Put was inhabited and its peaks appeared later.

  15. Burdock fructooligosaccharide enhances biocontrol of Rhodotorula mucilaginosa to postharvest decay of peaches.

    Science.gov (United States)

    Zhang, Hongyin; Liu, Zhouyang; Xu, Baitian; Chen, Keping; Yang, Qiya; Zhang, Qiuyun

    2013-10-15

    The influence of adding burdock fructooligosaccharide (BFO) in the culture media on the efficacy of Rhodotorula mucilaginosa in controlling postharvest decay of peaches and its possible mode of action were investigated. The antagonistic activity of R. mucilaginosa to Rhizopus decay and blue mold decay of peaches was greatly enhanced through cultivation in the nutrient yeast dextrose agar (NYDA) medium amended with BFO at the concentration of 0.32%, compared with that cultivated in NYDB without BFO. R. mucilaginosa at 1×10(8) cells/mL cultivation in the NYDB media did not reduce the natural decay incidence of peaches, compared with the control after 30 d at 4 °C followed by 7d at 20 °C. However, R. mucilaginosa cultivation in the NYDB media amended with BFO at the concentration of 0.32% reduced the natural decay incidence of peaches. The population of R. mucilaginosa harvested from NYDB amended with BFO at 0.32% increased rapidly in peach wounds compared to that harvested from NYDB without BFO no matter peaches were stored at 20 °C or 4 °C. The activities of chitinase and β-1,3-glucanase of cell-free culture filtrate of R. mucilaginosa harvested from NYDB amended with BFO at 0.32% were higher than that at other concentrations and the control. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Chitin enhances biocontrol of Rhodotorula mucilaginosa to postharvest decay of peaches.

    Science.gov (United States)

    Zhang, Hongyin; Yang, Qiya; Ge, Lingling; Zhang, Guochao; Zhang, Xiaoli; Zhang, Xiaoyun

    2016-07-01

    Biological control using microbial antagonists is a promising alternative approach to synthetic fungicides. However, effective biological control requires enhancing the consistency and efficacy of the antagonists used to control postharvest diseases. This study investigated the effect of chitin on the biocontrol efficacy of Rhodotorula mucilaginosa against blue mold and Rhizopus decay of peaches and on the protein expression profiles of R. mucilaginosa. The antagonistic activity of R. mucilaginosa harvested from the nutrient yeast dextrose broth (NYDB) with 0.5% chitin added was significantly improved compared with culture in NYDB without chitin. The R. mucilaginosa population cultured in chitin-supplement NYDB and nutrient yeast chitin borth (NYCB) harvested from peach wounds was more than that of R. mucilaginosa cultured in NYDB without chitin throughout the storage period except at 1 d. The protein expression profiles findings revealed that there were several differentially expressed proteins of R. mucilaginosa in the 0.5% chitin-supplemented NYDB and NYCB compared with that of R. mucilaginosa in NYDB. Most of these were cellular proteomes relating to the primary metabolic reactions such as glycoside hydrolases, phosphoribosyl pyrophosphate, and NADH dehydrogenases. Some proteins were also related to signal transmission and stress response. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Characteristics of postharvest quality in regional fruits treate with ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Josenilda M.; Villar, Heldio P. [Centro Regional de Ciencias Nucleares (CRCN/CNEN-NE), Recife, PE (Brazil)], e-mail: jmnilda@cnen.gov.br; Correia, Lidia C.S.A.; Maciel, Maria Ines S. [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil)], e-mail: aidil_alencar@yahoo.com.br, e-mail: marines@ufrpe.br

    2009-07-01

    In order to investigate the effects of irradiation on the main characteristics of quality postharvest of three cultivated species of the Northeast Region of Brazil, experiments with cashew (Anacardium occidentale L. var. Nanum), sapodilla (Manilkara sapodilla (L) Van Royen) and mangaba (Hancornia speciosa Gomes) have been performed. Cashew peduncles stored for fourteen days under 6.5 deg C had presented best results in the sensorial analyses for external appearance, flavour and aroma when irradiated with 1 kGy. sapodillas irradiated with doses of 300, 600 and 900 Gy have not displayed harmed sensorial qualities when stored under 20 deg C during twelve days. Doses up to 800 Gy had not harmed the external and internal appearance of mangabas after being stored for a fortnight under 13 deg C. Chemical characteristics of TSS, TTA, pH and solid/acidity ratio have not been affected significantly by the different doses applied to the three studied species. Amount of ascorbic acid was lower in the irradiated fruits, with significant differences for the species Anacardium occidentale L. var. Nanum and Hancornia speciosa Gomes. (author)

  18. Data supporting the role of enzymes and polysaccharides during cassava postharvest physiological deterioration.

    Science.gov (United States)

    Uarrota, Virgílio Gavicho; Moresco, Rodolfo; Schmidt, Eder Carlos; Bouzon, Zenilda Laurita; da Costa Nunes, Eduardo; de Oliveira Neubert, Enilto; Peruch, Luiz Augusto Martins; Rocha, Miguel; Maraschin, Marcelo

    2016-03-01

    This data article is referred to the research article entitled The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration by Uarrota et al. (2015). Food Chemistry 197, Part A, 737-746. The stress duo to PPD of cassava roots leads to the formation of ROS which are extremely harmful and accelerates cassava spoiling. To prevent or alleviate injuries from ROS, plants have evolved antioxidant systems that include non-enzymatic and enzymatic defence systems such as ascorbate peroxidase, guaiacol peroxidase and polysaccharides. In this data article can be found a dataset called "newdata", in RData format, with 60 observations and 06 variables. The first 02 variables (Samples and Cultivars) and the last 04, spectrophotometric data of ascorbate peroxidase, guaiacol peroxidase, tocopherol, total proteins and arcsined data of cassava PPD scoring. For further interpretation and analysis in R software, a report is also provided. Means of all variables and standard deviations are also provided in the Supplementary tables ("data.long3.RData, data.long4.RData and meansEnzymes.RData"), raw data of PPD scoring without transformation (PPDmeans.RData) and days of storage (days.RData) are also provided for data analysis reproducibility in R software.

  19. Effect of irradiation on the post-harvest life of potatoes

    International Nuclear Information System (INIS)

    Mahboob, F.; Badshah, N.; Jabeen, N.; Ayub, G.

    2004-01-01

    Research work was conducted to find out the effect of irradiation on the post-harvest life of potatoes. Cultivar Raja was obtained from Agricultural Research Institute, Tarnab, and irradiated by Cobalt-60 source at different doses 0, 5, 7.5, 10 and 15 Krad at the Nuclear Institute for Food and Agriculture (NIFA), Tarnab during the year 2002. The samples were then stored for three months at the Horticultural Research Farm, Malakandher, at a room temperature of 30-39 degree C and relative humidity of 29-63%. Various tests carried out at Food Science laboratory revealed that irradiation significantly affected the weight loss, sugars, starch, ascorbic acid, sprouting and specific gravity. It was observed that maximum sprouting has occurred in control (42.1%) followed by 5 Krad irradiated tubers (6.4%). While irradiation doses of 7.5, 10 and 15 Krad completely inhibited sprouting. Maximum percent decrease in weight (42.66%), reducing sugars (0.57%), non reducing sugars (0.87%), starch (12%), ascorbic acid (32%) and specific gravity (4%) were recorded for control while minimum percent decrease in weight (31.40%), reducing sugars (0.19%), non-reducing sugars (0.27%), starch (8.0%), ascorbic acid (12%) and specific gravity (1.7%) were noted for IS Krad irradiated tubers. Irradiation dose of 7.5 Krad seems to be better for the extension of shelf life of potatoes

  20. An attempt of postharvest orange fruit rot control using essential oils from Mediterranean plants.

    Science.gov (United States)

    Camele, Ippolito; De Feo, Vincenzo; Altieri, Luciana; Mancini, Emilia; De Martino, Laura; Luigi Rana, Gian

    2010-12-01

    Twelve essential oils from Mediterranean aromatic plants were tested at different doses against four fungi known as causal agents of post-harvest orange fruit rot: Botrytis cinerea, Penicillium italicum, Phytophthora citrophthora, and Rhizopus stolonifer. Essential oils were obtained from Hyssopus officinalis, Lavandula angustifolia, Majorana hortensis, Melissa officinalis, Ocimum basilicum, Origanum vulgare, Salvia officinalis, and Thymus vulgaris (Family Lamiaceae), Verbena officinalis (Family Verbenaceae), and Pimpinella anisum, Foeniculum vulgare, and Carum carvi (Family Apiaceae). Because preliminary in vitro experiments showed that only the oils from V. officinalis, T. vulgaris, and O. vulgare exhibited some fungistatic activity against the above-named fungi, these three essential oils were used in successive in vivo tests carried out to protect healthy "Washington navel" orange fruits from artificial infection by the same micromycetes. The essential oil of T. vulgaris, at a 2,000 ppm dose, controlled fruit rot by B. cinerea, P. citrophthora, and R. stolonifer but was ineffective against P. italicum. Essential oils of V. officinalis and O. vulgare inhibited infection by the first two fungi and only by P. citrophthora, respectively. This finding represents an important result, with the goal of using the essential oils as natural preservatives for food products, due to their positive effect on their safety and shelf life.

  1. Characteristics of postharvest quality in regional fruits treate with ionizing radiation

    International Nuclear Information System (INIS)

    Silva, Josenilda M.; Villar, Heldio P.; Correia, Lidia C.S.A.; Maciel, Maria Ines S.

    2009-01-01

    In order to investigate the effects of irradiation on the main characteristics of quality postharvest of three cultivated species of the Northeast Region of Brazil, experiments with cashew (Anacardium occidentale L. var. Nanum), sapodilla (Manilkara sapodilla (L) Van Royen) and mangaba (Hancornia speciosa Gomes) have been performed. Cashew peduncles stored for fourteen days under 6.5 deg C had presented best results in the sensorial analyses for external appearance, flavour and aroma when irradiated with 1 kGy. sapodillas irradiated with doses of 300, 600 and 900 Gy have not displayed harmed sensorial qualities when stored under 20 deg C during twelve days. Doses up to 800 Gy had not harmed the external and internal appearance of mangabas after being stored for a fortnight under 13 deg C. Chemical characteristics of TSS, TTA, pH and solid/acidity ratio have not been affected significantly by the different doses applied to the three studied species. Amount of ascorbic acid was lower in the irradiated fruits, with significant differences for the species Anacardium occidentale L. var. Nanum and Hancornia speciosa Gomes. (author)

  2. Comparative evaluation of six storage methods for postharvest preservation of cowpea grain

    KAUST Repository

    Baoua, I. B.; Amadou, L.; Margam, V.; Murdock, L. L.

    2012-01-01

    Several technologies reputedly minimize losses of stored cowpea grain to bruchid beetles on low resource farms in Africa. Side by side comparison of these different postharvest storage methods can provide the basis for deciding which performs best. We compared six different technologies for cowpea storage: (1) grain mixed with ash; (2) mixed with sand; (3) fumigated with phostoxin; (4) admixed with the stems and leaves of . Boscia senegalensis (Pers) Lam ex Poir, a potential botanical insecticide; (5) disinfested using a solar heater, and; (6) hermetically sealed in triple-layer plastic bags. Sampling was done at thirty-day intervals over five months of storage. Counts were made of (i) adult emergence holes, (ii) dead larvae and (iii) surviving bruchid larvae and adults. Controls, which consisted of infested cowpea grain stored in cloth bags, were damaged extensively. . Boscia senegalensis-treated grain suffered similar severe damage. All other treatments suppressed bruchid population increases as was evident from the much lower counts of emergence holes and lower numbers of surviving or dead insects. © 2012 Elsevier Ltd.

  3. Ultralow oxygen treatment for postharvest control of Nasonovia ribisnigri (Homoptera: Aphididae) on iceberg lettuce.

    Science.gov (United States)

    Liu, Yong-Biao

    2005-12-01

    The aphid Nasonovia ribisnigri (Mosley) is a common pest of lettuce in the United States. It hinders export of U.S. lettuce to the overseas market such as Japan where it is a quarantined pest. Ultralow oxygen treatments were studied for control of the insect on iceberg lettuce. Small-scale ultralow oxygen treatments in plastic jars were conducted at 1, 5, and 10 degrees C for different durations to determine effective treatment against nymphs and alates of N. ribisnigri. At oxygen levels of 0.015-0.025%, N. ribisnigri can be controlled in 3 d at 1 degrees C, 2 d at 5 degrees C, and 1 d at 10 degrees C. Large-scale ultralow oxygen treatments were conducted in bulk container treatment chambers with commercial iceberg lettuce heads for 2 d at 6 degrees C with oxygen levels of 0.015 and 0.025% and for 3 d at 3 degrees C with oxygen level of 0.015%. All treatments achieved complete control of N. ribisnigri. No negative impact on lettuce quality was detected after 2 wk of posttreatment storage. Therefore, the selected treatments have potential to be commercially developed for postharvest control of N. ribisnigri on iceberg lettuce.

  4. Effect of different 1-methylcyclopropene doses on the postharvest period of pitahaya fruits (Selenicereus megalanthus Haw.

    Directory of Open Access Journals (Sweden)

    Javier Giovanni Álvarez-Herrera

    2016-07-01

    application of 1-methylcyclopropene (1-MCP on the preservation and quality of dragon fruit, given that it has been effective in the conservation and postharvest quality of many agricultural species allowing longer life, using a completely randomized experiment design with three treatments: 0, 300 and 600 mg L-1 of 1-MCP, with four replications. The 600 mg L-1 of 1-MCP dose was able to maintain the quality of the dragon fruit longer (28 days after harvest (dah because it managed to reduce the respiratory rate. The application of 1-MCP did not affect the firmness, loss of mass, total soluble solids, total titratable acidity, or total carotenoids in the fruits. The application of 1-MCP slowed the loss of fruit quality in terms of color because the 600 mg L-1 dose maintained the lightness of the fruits longer, reduced the color changes as expressed in a* and b* values and decreased the chlorophyll degradation.

  5. Ethylene and 1-MCP affect the postharvest behavior of yellow pitahaya fruits (Selenicereus megalanthus Haw.

    Directory of Open Access Journals (Sweden)

    Yuli Alexandra Deaquiz

    2014-04-01

    Full Text Available The pitahaya or dragon fruit is one of the most representative exotic fruits that Colombia has, with an important, growing international market, but the cultivation and postharvest of this fruit lack sufficient technological support to be more competitive. Therefore, alternatives that provide good-quality products that meet market requirements are very important. Therefore, the objective of this research was to determine the effect of a ripening retardant and ethylene application on the conservation and quality of pitahaya fruits and the possible changes during ripening associated with ethylene, for which a completely randomized design with three treatments was used, corresponding to the application of ethylene (ethephon, 3 mL L-1, 1-methylcyclopropene (1-MCP, 600 mg L-1 and a control, with four replications, for a total of 12 experimental units. The fruits were stored at 18°C with 75% relative humidity. The 1-MCP application significantly decreased the loss of firmness, total soluble solids, loss of fresh mass and respiratory rate. Fruits from the control and ethylene treatment tended toward a climateric respiratory behavior. The total carotenoid content of the fruits was significantly higher in the ethylene application and the control treatment, which was consistent with the color change of the fruits. It can be concluded that the 1-MCP application reduced the ethylene action, slowing the ripening of the dragon fruits.

  6. Post-harvest UVC irradiation effect on anthocyanin profile of grape berries

    International Nuclear Information System (INIS)

    Rosas, I. de; Ponce, M.; Gargantini, R.; Martinez, L.

    2010-01-01

    Anthocyanins are a class of phenolic compounds that contribute to the color of red grapes and have shown nutraceutical properties for human health. UVC light irradiation has been proved to increase phenolic compounds such as stilbenes, but its effect on anthocyanins has not been reported. The aim of this work was to identify the best treatment conditions of UVC light irradiation on post-harvest berries of Malbec (M), Cabernet Sauvignon (CS) and Tempranillo (T) for anthocyanin increments. Grape berries were irradiated with 240 W at 20 and 40 cm from the light source, for 30, 60 and 120 seconds. Both, irradiated and control grapes were stored on darkness at 20 C degree until anthocyanin extraction with methanol/ClH. HPLC analysis were performed and nine anthocyanins were quantified. UVC light irradiation modified the anthocyanin profile of the three cultivars. All the glucoside anthocyanins derivates and peonidin-acetyl-glucoside, as well as total anthocyanins were increased when CS berries were exposed to UVC for 120 s at 40 cm. This suggests that UVC stimulated the entire biosynthetic pathway. The anthocyanin content of the control berries was always higher than the treatments with UVC on M and T, making necessary to evaluate less rigorous conditions for these varieties. (authors)

  7. The anti-senescence effect of resveratrol reduces postharvest softening rate in cherimoya fruit

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    Aaran Aquilino Morales Pérez

    2014-03-01

    Full Text Available Due to its climateric behavior, the cherimoya fruit (Annona cherimola Mill. is a very perishable commodity. Present research aimed to observe the anti-senescence effect of resveratrol (RVS; this plant bioregulator was applied at 1.6, 0.16, 0.016 and 0 mM at 0, 8 and 15 days before harvest (DBH. At 1, 7 and 15 days of postharvest life, several physical and biochemical determinations were performed on the cherimoya fruit. After 15 days under room temperature conditions, in relation to control fruit, those fruit with 1.6 mM RVS applied 15 DBH reduced skin softening rate 78% and 54% for ‘Fino de Jete’ and ‘Bronceada’, respectively. Similarly, after 15 days of storage, a non-trained group of tasters preferred those fruit treated with 1.6 mM RVS 15 DBH; they qualified the fruit as better than the control fruit in presentation, aroma and taste.

  8. Aspergillus flavus: human pathogen, allergen and mycotoxin producer.

    Science.gov (United States)

    Hedayati, M T; Pasqualotto, A C; Warn, P A; Bowyer, P; Denning, D W

    2007-06-01

    Aspergillus infections have grown in importance in the last years. However, most of the studies have focused on Aspergillus fumigatus, the most prevalent species in the genus. In certain locales and hospitals, Aspergillus flavus is more common in air than A. fumigatus, for unclear reasons. After A. fumigatus, A. flavus is the second leading cause of invasive aspergillosis and it is the most common cause of superficial infection. Experimental invasive infections in mice show A. flavus to be 100-fold more virulent than A. fumigatus in terms of inoculum required. Particularly common clinical syndromes associated with A. flavus include chronic granulomatous sinusitis, keratitis, cutaneous aspergillosis, wound infections and osteomyelitis following trauma and inoculation. Outbreaks associated with A. flavus appear to be associated with single or closely related strains, in contrast to those associated with A. fumigatus. In addition, A. flavus produces aflatoxins, the most toxic and potent hepatocarcinogenic natural compounds ever characterized. Accurate species identification within Aspergillus flavus complex remains difficult due to overlapping morphological and biochemical characteristics, and much taxonomic and population genetics work is necessary to better understand the species and related species. The flavus complex currently includes 23 species or varieties, including two sexual species, Petromyces alliaceus and P. albertensis. The genome of the highly related Aspergillus oryzae is completed and available; that of A. flavus in the final stages of annotation. Our understanding of A. flavus lags far behind that of A. fumigatus. Studies of the genomics, taxonomy, population genetics, pathogenicity, allergenicity and antifungal susceptibility of A. flavus are all required.

  9. TAXONOMY OF FUSARIUM SPECIES ISOLATED FROM CULTIVATED PLANTS, WEEDS AND THEIR PATHOGENICITY FOR WHEAT

    Directory of Open Access Journals (Sweden)

    Jasenka Ćosić

    2002-06-01

    Full Text Available Fusarium species are wide-spread and known to be pathogenic agents to cultivated plants in various agroclimatic areas. During a four year investigation 10 Fusarium species and Microdochium nivale were isolated from wheat, barley, maize and soybean as well as from 10 weeds collected from 10 locations in Slavonia and Baranya. Fusarium graminearum was dominant on wheat and barley, F. moniliforme on maize and F. oxysporum on soybean. Regarding weeds, the presence of the following Fusarium species was established: F. graminearum on Amaranthus hybridus, Capsella bursa-pastoris, Lamium purpureum, Sorghum halepense and Urtica dioica, F. moniliforme on Abutilon theophrasti, F. subglutinans on Polygonum aviculare, F. avenaceum on Capsella bursa-pastoris, Rumex crispus and Matricaria sp., F. culmorum on Abutilon theophrasti, F. sporotrichioides on Polygonum aviculare, F. proliferatum and F. poae on Artemisia vulgaris. Pathogenicity test to wheat seedlings was done in our laboratory on winter wheat cultivars Slavonija and Demetra (totally 146 isolates. The most pathogenic species to wheat seedilings were F. graminearum, F. culmorum and F. sporotrichioides and the least pathogenic F. moniliforme, F. solani, F. oxysporum and F. poae. Pathogenicity test for wheat ears was done on genotypes Osk.8c9/3-94 and Osk.6.11/2 (totally 25 isolates. The results obtained by our investigation showed that there were no significant differences in pathogenicity of Fusarium species isolated from both cultivated plants and weeds. Weeds represent a constant source of inoculum of F. species for cultivated plants and they serve as epidemiologic bridges among vegetations.

  10. High relative humidity pre-harvest reduces post-harvest proliferation of Salmonella in tomatoes

    NARCIS (Netherlands)

    Devleesschauwer, Brecht; Marvasi, Massimiliano; Giurcanu, Mihai C.; Hochmuth, George J.; Speybroeck, Niko; Havelaar, Arie H.; Teplitski, Max

    2017-01-01

    Outbreaks of human illness caused by enteric pathogens such as Salmonella are increasingly linked to the consumption of fruits and vegetables. Knowledge on the factors affecting Salmonella proliferation on fresh produce therefore becomes increasingly important to safeguard public health. Previous

  11. Elaboration and quality control of the inoculum of the experimental vaccine Brucella S19-tn7-GFP for use in white animals and associated serological test for the detection of anti-GFP antibodies

    International Nuclear Information System (INIS)

    Salas Alfaro, Dariana

    2014-01-01

    The preparation of the inoculum of the experimental vaccine Brucella S19-Tn7-GFP is optimized for application in white animals. An associated serological test has allowed differentiating infected animals from those vaccinated with the experimental strain. The same bacteriological and biological properties of the B. abortus S19-Tn7-GFP strain have maintained in the parental vaccine strain S19 and is stable over time. A protocol for the inoculums of strain S19-Tn7-GFP is established for its preparation and use in white animals and quality control. The inoculum stability is evaluated through the simulation of conditions that can be presented in the transportation and application process in the field. An enzyme immunoassay ELISA is optimized for the detection of anti-GFP antibodies in cattle [es

  12. Antifungal activity of 1-methylcyclopropene (1-MCP) against anthracnose (Colletotrichum gloeosporioides) in postharvest mango fruit and its possible mechanisms of action.

    Science.gov (United States)

    Xu, Xiangbin; Lei, Huanhuan; Ma, Xiuyan; Lai, Tongfei; Song, Hongmiao; Shi, Xuequn; Li, Jiangkuo

    2017-01-16

    Anthracnose caused by Colletotrichum gloeosporioides is one of the most important postharvest diseases in mango fruit, often causing huge economic losses. In this study, the effect of 1-methylcyclopropene (1-MCP) against anthracnose in postharvest mango fruit and the mechanisms involved were investigated. 1-MCP induced reactive oxygen species (ROS) generation, damaged the mitochondria and destroyed the integrity of plasma membrane of spores of C. gloeosporioides, significantly suppressing spore germination and mycelial growth of C. gloeosporioides. 1-MCP also decreased the decay incidence and lesion expansion of mango fruit caused by C. gloeosporioides. For the first time this study demonstrated that 1-MCP suppressed anthracnose of postharvest mango fruit by directly inhibiting spore germination and mycelial growth of C. gloeosporioides, thus providing a promising strategy for disease control. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Relevance of the main postharvest handling operations on the development of brown rot disease on stone fruits.

    Science.gov (United States)

    Bernat, Maria; Segarra, Joan; Casals, Carla; Teixidó, Neus; Torres, Rosario; Usall, Josep

    2017-12-01

    Brown rot caused by Monilinia spp. is one of the most important postharvest diseases of stone fruit. The aim of this study was to evaluate the relevance of the main postharvest operations of fruit - hydrocooling, cold room, water dump, sorting and cooling tunnel - in the development of M. laxa on peaches and nectarines artificially infected 48, 24 or 2 h before postharvest operations. Commercial hydrocooling operation reduced incidence to 10% in 'Pp 100' nectarine inoculated 2 and 24 h before this operation; however, in 'Fantasia' nectarine incidence was not reduced, although lesion diameter was decreased in all studied varieties. Hydrocooling operation for 10 min and 40 mg L -1 of sodium hypochlorite reduced brown rot incidence by 50-77% in nectarines inoculated 2 h before operation; however, in peach varieties it was not reduced. Water dump operation showed reduction of incidence on nectarine infected 2 h before immersion for 30 s in clean water at 4 °C and 40 mg L -1 sodium hypochlorite; however, in peach varieties it was not reduced. Cold room, sorting and cooling tunnel operation did not reduce brown rot incidence. From all studied handling operations on stone fruit packing houses, hydrocooling is the most relevant in the development of brown rot disease. Duration of the treatment seems to be more important than chlorine concentration. In addition, hydrocooling and water dump were less relevant in peaches than in nectarines. As a general trend, hydrocooling and water dump reduced incidence on fruit with recent infections (2 or 24 h before operation); however, when infections have been established (48 h before operation) diseases were not reduced. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Preservação do inóculo de Plasmodiophora brassicae utilizando o método de congelamento Preservation of Plasmodiophora brassicae inoculum using the freezing method

    Directory of Open Access Journals (Sweden)

    Juliana Cristina Sodário Cruz

    2009-02-01

    brassica species naturally infected by P. brassicae, showing typical clubroot symptoms, sampled in the same farm, located in the Pardinho County, State of São Paulo, were collected during different seasons and were immediately frozen at approximately 20ºC. The treatments were divided as follows: T1: clubroots frozen for 389 days (arugula; T2: clubroots frozen for 242 days (broccoli; T3: clubroots frozen for 21 days (Chinese cabbage, and T4: control (without inoculum. The pathogenicity tests were conducted under greenhouse conditions (25±2ºC. Each plant of the susceptible variety of Chinese cabbage (Pak choi was inoculated with 2mL of a spore suspension of each treatment at a concentration of 10(7 spores.mL-1. Each treatment consisted of six replicates distributed in random blocks. The roots of plants were washed and evaluated five weeks after inoculation. There were significant differences between treatments. The frozen materials preserved their infective traits over a period of 21 to 242 days, demonstrating that the freezing method could be an option to preserve the resistance structures of this pathogen.

  15. Repeated applications of CPPU on highbush blueberry cv. Duke increase yield and enhance fruit quality at harvest and during postharvest

    Directory of Open Access Journals (Sweden)

    Jorge B Retamales

    2014-04-01

    Full Text Available Applications of N-(2-chloro-4-pyridyl-N'-phenylurea (CPPU can increase blueberry (Vaccinium corymbosum L. yield and fruit size, but their impact on postharvest is unknown. We studied repeated CPPU applications effects on yield and quality (harvest, postharvest, over 2 yr on mature 'Duke' plants in South-Central Chile. The first year, 5 or 10 mL L-1 CPPU was applied at 3, 10, and/or 17 d after full bloom (DAFB plus a non-sprayed control. The second year, 5 or 10 mL L-1 CPPU were sprayed 10 and 17 DAFB plus a control. The first year, only 10 mL L-1 CPPU sprayed 3+17 DAFB increased yield (32.5% > control; 10 mL L-1 CPPU applied 10 or 3+17 DAFB had highest fruit diameter; and 10 mL L-1 CPPU at 17 DAFB or at 3+10+17 DAFB had highest soluble solids. Overall, 10 mL L-1 CPPU applied 3+17 DAFB, was the best treatment for year one, since it increased fruit yield and diameter, while soluble solids and postharvest weight loss were similar to control. The second year, 10 mL L-1 CPPU reduced fruit coloration (blue color coverage index: BCCI and soluble solids, but not firmness at harvest. This rate increased berry weight (24.2% and fruit wax (59% > wax coverage index: WCI at harvest. Harvest and postharvest WCI increased consistently as CPPU rate increased. CPPU reduced fruit rotting (15% at 45+5 evaluation. During storage, CPPU-treated-fruit had a slower decrease in firmness (30.5% < control at 30+1, but no difference at 30+5. CPPU-treated-fruit usually had higher post harvest soluble solids. Ten mL L-1 CPPU retarded color evolution at harvest and at 30+1, but not at 30+5, 40+1 or 40+5.

  16. Effect of pre-harvest fruit bagging on post-harvest quality of guava cv. Swarupkathi

    Directory of Open Access Journals (Sweden)

    Md. Mokter Hossain

    2018-04-01

    The investigation was carried out at Germplasm Centre (BAU-GPC, Bangladesh Agricultural University, during March to July 2016 in order to investigate the effect of pre-harvest fruit bagging on post-harvest quality of guava cv. Swarupkathi. Four different bagging materials viz. brown paper bag, white paper bag, white polythene bag, black polythene bag included for the study and uncovered fruits were used as control treatment. The experiment was laid out in randomized complete block design with three replications. Fruit bagging treatments showed significant effects on different parameters studied. It was observed that fruit size, fruit weight, vitamin C concentration, and moisture content increased due to fruit bagging. Fruits were gained maximum in size (6.59 cm length, 5.86 cm diameter and weight (164.26 g under white paper bag followed by white polythene bag (131.3g. The skin color of fruits was very attractive in case of white paper bag than that of other treatments. Total soluble solid concentration of the fruit was found maximum (12.33% Brix under brown paper bag while maximum vitamin C concentration (162.14 mg 100 g-1 was recorded under white paper bag. Uncovered fruits showed maximum total sugar, non-reducing sugar, reducing sugar concentrations (10.13%, 6.05%, 4.08%, respectively.The results revealed that fruit bagging in general, improved the growth and quality of guava fruits as compared to control. Among the various fruit covering materials, white paper bag was found to be the best for overall improvement of physical and chemical quality of guava cv. Swarupkathi. [Fundam Appl Agric 2018; 3(1.000: 363-371

  17. Bioactive maca (Lepidium meyenii) alkamides are a result of traditional Andean postharvest drying practices.

    Science.gov (United States)

    Esparza, Eliana; Hadzich, Antonella; Kofer, Waltraud; Mithöfer, Axel; Cosio, Eric G

    2015-08-01

    Maca, Lepidium meyenii Walpers (Brassicaceae), is an annual herbaceous plant native to the high plateaus of the Peruvian central Andes. Its underground storage hypocotyls have been a traditional medicinal agent and dietary staple since pre-Columbian times. Reported properties include energizing and fertility-enhancing effects. Published reports have focused on the benzylalkamides (macamides) present in dry hypocotyls as one of the main bioactive components. Macamides are secondary amides formed by benzylamine and a fatty acid moiety, with varying hydrocarbon chain lengths and degree of unsaturation. Although it has been assumed that they are usually present in fresh undamaged tissues, analyses show them to be essentially absent from them. However, hypocotyls dried by traditional Andean postharvest practices or industrial oven drying contain up to 800μgg(-1) dry wt (2.3μmolg(-1) dry wt) of macamides. In this study, the generation of macamides and their putative precursors were studied during nine-week traditional drying trials at 4200m altitude and in ovens under laboratory conditions. Freeze-thaw cycles in the open field during drying result in tissue maceration and release of free fatty acids from storage and membrane lipids up to levels of 1200μgg(-1) dry wt (4.3μmolg(-1) dry wt). Endogenous metabolism of the isothiocyanates generated from glucosinolate hydrolysis during drying results in maximal benzylamine values of 4300μgg(-1) dry wt (40.2μmolg(-1) dry wt). Pearson correlation coefficients of the accumulation profiles of benzylamine and free fatty acid to that of macamides showed good values of 0.898 and 0.934, respectively, suggesting that both provide sufficient substrate for amide synthesis during the drying process. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. POSTHARVEST QUALITY OF FEIJOA FLOWERS TREATED WITH DIFFERENT PRESERVATIVE SOLUTIONS AND 1-METHYLCYCLOPROPENE

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    ALEXANDRA GOEDE DE SOUZA

    Full Text Available ABSTRACT This study was carried out to assess the postharvest quality preservation of feijoa(Acca sellowiana Berg flowers in response to treatments with different preservative solutions and 1-methylcyclopropene (1-MCP. Recently opened feijoa flowers were harvested in the morning (between 8h and 10h and immediately after pulsed with preservative solutions of salicylic acid, ascorbic acid and sucrose, all at doses of 0 (control, 2, 5 or 10%, and treated with 1-MCP at doses of 0 (control, 250, 500 or 1,000 nL L-1. Each trial with preservative solutions or 1-MCP treatment was a distinct experiment conducted in a completely randomized design with four replicates, each replicate with four flowers. After the treatment, the flowers were stored for 12 days at 10±1 oC and 85±5% RH. At every two-days intervals the flower petals were visually evaluated for wilting and darkening according to a hedonic scale varying from 1 (less intense to 5 (more intense. Petal color was ranked from 1 (intense pink to 5 (white. The 1-MCP at 500 nL L-1 and the salicylic acid (regardless of the dose delayed the changes of petal color for up to eight and six days of storage, respectively. Flowers treated with salicylic acid, 1-MCP or ascorbic acid had a more substantial delay in petal wilting. Flowers treated with salicylic acid had wilting rank of 2 after six days of storage when treated with doses of 5% or 10%, and after eight days when treated with the dose of 2%, while flowers treated with 1-MCP at 500 and 1,000 nL L-1 and ascorbic acid at 2% and 5% had wilting rank of 2 after four days of storage. The most substantial delay of petal darkening (until the fourth day of storage was achieved with 1-MCP at 500 nL L-1.

  19. Analysis of ethylene biosynthesis and perception during postharvest cold storage of Marsh and Star Ruby grapefruits.

    Science.gov (United States)

    Lado, Joanna; Rodrigo, María Jesús; Zacarías, Lorenzo

    2015-10-01

    Grapefruits are among the citrus species more sensitive to cold and develop chilling injury symptoms during prolonged postharvest storage at temperatures lower than 8 ℃-10 ℃. The plant hormone ethylene has been described either to protect or potentiate chilling injury development in citrus whereas little is known about transcriptional regulation of ethylene biosynthesis, perception and response during cold storage and how the hormone is regulating its own perception and signaling cascade. Then, the objective of the present study was to explore the transcriptional changes in the expression of ethylene biosynthesis, receptors and response genes during cold storage of the white Marsh and the red Star Ruby grapefruits. The effect of the ethylene action inhibitor, 1-MCP, was evaluated to investigate the involvement of ethylene in the regulation of the genes of its own biosynthesis and perception pathway. Ethylene production was very low at the harvest time in fruits of both varieties and experienced only minor changes during storage. By contrast, inhibition of ethylene perception by 1-MCP markedly induced ethylene production, and this increase was highly stimulated during shelf-life at 20 ℃, as well as transcription of ACS and ACO. These results support the auto-inhibitory regulation of ethylene in grapefruits, which acts mainly at the transcriptional level of ACS and ACO genes. Moreover, ethylene receptor1 and ethylene receptor3 were induced by cold while no clear role of ethylene was observed in the induction of ethylene receptors. However, ethylene appears to be implicated in the transcriptional regulation of ERFs both under cold storage and shelf-life. © The Author(s) 2014.

  20. Performance of triple bagging hermetic technology for postharvest storage of cowpea grain in Niger

    KAUST Repository

    Baoua, Ibrahim B.

    2012-10-01

    Triple bagging technology for protecting postharvest cowpea grain from losses to the bruchid, Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae: Bruchinae) is currently being adopted on a fairly large scale in ten West and Central African countries, including Niger. The triple bag consists of two inner high-density polyethylene bags acting as oxygen barriers, which in turn are encased in an outer woven polypropylene bag that serves primarily for mechanical strength. These hermetic bags, available in either 50 or 100 kg capacity, are called Purdue Improved Cowpea Storage (PICS) bags. Adoption of PICS technology in West and Central Africa has been driven by its effectiveness, simplicity, low cost, durability, and manufacture within the region. From surveys on adoption we discovered that farmers have begun to re-use bags they had used the previous year or even the previous two years. In the present study, we compared the performance of three different types of PICS bags: (1) new 50 kg (2) new 100 kg bags and (3) once-used 50 kg bags, all filled with naturally infested untreated cowpeas. In these PICS bags the O 2 levels within the bags initially fell to about 3 percent (v/v) while the CO 2 rose to nearly 5 percent (v/v). After five months of storage, new and used 50 kg bags and new 100 kg bags preserved the grain equally well. There were greatly reduced numbers of adults and larvae in the PICS bags versus the controls, which consisted of grain stored in single layer woven bags. The proportion of grain having C. maculatus emergence holes after five months of storage in PICS bags was little changed from that found when the grain was first put into the bags. The PICS technology is practical and useful in Sahelian conditions and can contribute to improved farmers\\' incomes as well as increase availability of high quality, insecticide-free cowpea grain as food. © 2012 Elsevier Ltd.

  1. Behavioral pattern of physicochemical constituents of the postharvest mango (Mangifera indica L.) influenced by storage stimuli.

    Science.gov (United States)

    Islam, Md Khairul

    2013-12-15

    An investigation was carried at the laboratory of the Department of Biochemistry and Molecular Biology, University of Rajshahi, Bangladesh during the period from May, 2010 to September, 2011 to study the behavioral pattern of some physicochemical constituents of the mango pulp. The experiment was comprised of two popular mango cultivars in Bangladesh (viz., Langra and Khirshapat) and six storage stimuli, namely control, paraffin coating, perforated polyethylene cover, unperforated polyethylene cover, hot water (55 +/- 1 degree C) and low temperature (4 +/- 1 degree C). The two factors experiment was assigned in randomized complete block design with tree replicates. The varieties had profound variation in terms of most of the characters studied in the laboratory condition. Initially the Langra significantly enriched a greater amount of vitamin C (151.23 mg/100 g) and titratable acidity (4.31%) and these were decreased gradually with the progress of storage period. The Khirshapat showed higher pulp pH (5.83); produced enormous amount of TSS (18.00%) and sugar (TS = 17.62%, RS = 6.51% and NRS = 11.06%) content at 12th day of storage. The pH, TSS, sugar (TS, RS and NRS) content of mango pulp was rapidly increased, whereas vitamin C and titratable acidity decreased drastically from the untreated mangoes. On the other hand, low temperature retarded the changes. The Langra using low temperature (4 +/- 1 degree C) exhibited lower diminishing tendency in vitamin C and titratable acidity and also using no treatment slightly increased TSS; enriched enormous amount of sugar (TS, RS and NRS). Therefore, low temperature (4 +/- 1 degree C) was found satisfactory for delay ripening and postharvest changes of mango in storage condition.

  2. Effect of salicylic acid and aloe vera gel on postharvest quality of table grapes ( Vitis Vinifera

    Directory of Open Access Journals (Sweden)

    H. Peyro

    2017-06-01

    Full Text Available To investigate the effects of salicylic acid dipping and Aloe vera gel coating on shelf life and post harvest quality of table grapes (Vitis vinifera of the cultivar Shahroudi, a factorial experiment was conducted on the basis of randomized complete blocks design with three factors and three replicates in agricultural faculty of Islamic Azad University in 2014. The treatments were dipping in Salicylic acid (three levels of 0, 1 and 2 mmmol-1 for 15 minutes and coating with Aloe vera gel (four levels of 0, 10%, 15% and 20% w/v and measurement of traits in 1st day, 30th day and 60th day after treatment of berries. The results showed that the interaction effect of salicylic acid and Aloe vera gel application was significant on all of traits except for pH value in a way that the best and the minimum weight loss (0.09g was obtained by application of 2 mmol-1 Salicylic acid and 20% Aloe vera gel in 1st day after treatment. The greatest amount of total soluble solids (428.43 g.100g-1 fruit juice was found in 2 mmol-1 Salicylic acid and 15% Aloe vera gel in 60th day. The highest Catalase enzyme activity (0.0013 Ua.mg-1Pro was attained in 2 mmol-1 Salicylic acid and 15% Aloe vera gel in 30th day. These results demonstrated that treatment of grape berries by salicylic acid and Aloe vera gel had positive effect on shelf life of table grapes and their postharvest quality

  3. Two endogenous substrates for polyphenoloxidase in pericarp tissues of postharvest rambutan fruit.

    Science.gov (United States)

    Sun, Jian; Su, Weiqiang; Peng, Hongxiang; Zhu, Jianhua; Xu, Liangxiong; Bruñá, Nuria Martí

    2010-08-01

    The catalytic oxidation of phenolic substrates by polyphenoloxidase (PPO) causes pericarp browning of postharvest rambutan fruit. In the present study, PPO and its endogenous substrates were extracted from rambutan pericarp tissues (RPT). The substrate extracts were sequentially partitioned with ethyl acetate and n-butanol. The analysis of total phenolic content showed that the most phenolic compounds were distributed in ethyl acetate fraction. By high-performance liquid chromatography (HPLC), (-)-epicatechin (EC) and proanthocyanidin A2 (PA2) were identified from this fraction. After reacting with rambutan PPO, EC turned brown rapidly within 10 min, indicating that it was a significant endogenous substrate. Although PA2 could also be oxidized by the PPO, it turned brown very slowly. In addition, because EC and PA2 were continually catalyzed into browning products by PPO during storage of the fruit at 4 and 25 degrees C, their contents in RPT gradually declined with the extended storage time. It was further observed that both substrate contents in rambutan fruit storing at 25 degrees C decreased more rapidly than that storing at 4 degrees C, suggesting that low temperature inhibited the catalytic oxidation of substrates so as to slow down pericarp browning. Practical Application: Pericarp browning is a serious problem to storage and transport of harvested rambutan fruit. A generally accepted opinion on the browning mechanism is the oxidation of phenolic substrates by PPO. Ascertaining PPO substrates will effectively help us to control enzymatic reaction by chemical methods so as to delay or even prevent pericarp browning of harvested rambutan fruit.

  4. EFFECTS OF HEAT TREATMENT AND CALCIUM ON POSTHARVEST STORAGE OF ATEMOYA FRUITS*

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    LIZ MARIA ABI RACHED TORRES

    2010-03-01

    Full Text Available

    The aim of the present study was to investigate the effect of postharvest warm dipping with calcium chloride (CaCl2 on atemoya fruit (Annona cherimola Mill x Annona squamosa L. storage. Fruits were immersed in 6% CaCl2 solution at 20 and 40°C for 20 min followed by storage at room temperature. The effectiveness of the treatment was assessed in terms of its impact on peel and fl esh appearance, weight loss, total soluble solids (TSS, total titratable acidity (TTA, pH, ascorbic acid content, total phenolics, and enzyme activities of polyphenoloxidase (PPO and peroxidase (POD. Treatment at 40°C preserved eatable conditions up to 6 days, although calcium affected the appearance of the peel as soon as 4 days. Flesh browning was detected only on the 8th day in untreated fruits, after an increase in PPO and POD activities and total phenolics, and a decrease in ascorbic acid content. The weight loss was continuous throughout the storage period, with no signifi cant difference between treatments. TTA and TSS contents increased and pH decreased during the experiment. Results suggest that CaCl2 dipping had a positive effect on fl esh browning, which was reduced, while heat treatment showed a synergic effect, which could be related broadly with a fall in PPO activity. The variations in ascorbic acid content during storage suggest that the warm dipping combined with CaCl2, contributed to the antioxidant capacity of the fruit.

  5. Combining color chart, colorimetric measurement and chemical compounds for postharvest quality of white wine grapes.

    Science.gov (United States)

    Sollazzo, Marco; Baccelloni, Simone; D'Onofrio, Claudio; Bellincontro, Andrea

    2018-01-03

    This paper provides data for the potential use of a color chart to establish the best quality of white wine grapes destined for postharvest processing. Grechetto, Vermentino and Muscat of Alexandria white wine grape varieties were tested by sampling berries at different dates during their quality attribute evolution. A color chart and reflectance spectrocolorimeter were used in combination with analyses of total carotenoids and chlorophylls in all three varieties and of volatile organic compounds (VOCs) in Grechetto alone. Total carotenoids decreased from 0.85 to 0.76 µg g -1 in Grechetto berries and from 0.70 to 0.46 µg g -1 in Vermentino berries while increased from 0.70 to 0.80 µg g -1 in Muscat berries during ripening. Total chlorophylls decreased in all varieties, and a strict correlation was found between hue angle (measured by color chart or spectrocolorimeter) and chlorophyll disappearance, with R 2 ranging from 0.81 to 0.95 depending on the variety. VOCs were only measured in Grechetto grapes, and a significant increase in glycosylation was found with ripening. The concentration of different classes of VOCs exhibited a clear decrease during ripening, except for terpenoids and esters which showed a peak at the beginning. The benzenoid class reached the highest concentration, which was almost 50% of the total. Cluster analysis using Ward's method enabled the best grape quality to be identified. This experimental work highlights that a color chart is cheap and easy to use to define the right quality stage for white wine grapes. The color chart enabled the enochemical features to be matched with the VOC results for the aromatic maturity of Grechetto. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  6. Quantifying Residues from Postharvest Propylene Oxide Fumigation of Almonds and Walnuts.

    Science.gov (United States)

    Jimenez, Leonel R; Hall, Wiley A; Rodriquez, Matthew S; Cooper, William J; Muhareb, Jeanette; Jones, Tom; Walse, Spencer S

    2015-01-01

    A novel analytical approach involving solvent extraction with methyl tert-butyl ether (MTBE) followed by GC was developed to quantify residues that result from the postharvest fumigation of almonds and walnuts with propylene oxide (PPO). Verification and quantification of PPO, propylene chlorohydrin (PCH) [1-chloropropan-2-ol (PCH-1) and 2-chloropropan-1-ol (PCH-2)], and propylene bromohydrin (PBH) [1-bromopropan-2-ol (PBH-1) and 2-bromopropan-1-ol (PBH-2)] was accomplished with a combination of electron impact ionization MS (EIMS), negative ion chemical ionization MS (NCIMS), and electron capture detection (ECD). Respective GC/EIMS LOQs for PPO, PCH-1, PCH-2, PBH-1, and PBH-2 in MTBE extracts were [ppm (μg/g nut)] 0.9, 2.1, 2.5, 30.3, and 50.0 for almonds and 0.8, 2.2, 2.02, 41.6, and 45.7 for walnuts. Relative to GC/EIMS, GC-ECD analyses resulted in no detection of PPO, similar detector responses for PCH isomers, and >100-fold more sensitive detection of PBH isomers. NCIMS did not enhance detection of PBH isomers relative to EIMS and was, respectively, approximately 20-, 5-, and 10-fold less sensitive to PPO, PCH-1, and PCH-2. MTBE extraction efficiencies were >90% for all analytes. The 10-fold concentration of MTBE extracts yielded recoveries of 85-105% for the PBH isomers and a concomitant decrease in LODs and LOQs across detector types. The recoveries of PCH isomers and PPO in the MTBE concentrate were relatively low (approximately 50 to 75%), which confound improvements in LODs and LOQs regardless of detector type.

  7. Efficacy of gaseous ozone to counteract postharvest table grape sour rot.

    Science.gov (United States)

    Pinto, L; Caputo, L; Quintieri, L; de Candia, S; Baruzzi, F

    2017-09-01

    This work aims at studying the efficacy of low doses of gaseous ozone in postharvest control of the table grape sour rot, a disease generally attributed to a consortium of non-Saccharomyces yeasts (NSY) and acetic acid bacteria (AAB). Sour rot incidence of wounded berries, inoculated with 8 NSYstrains, or 7 AAB, or 56 yeast-bacterium associations, was monitored at 25 °C up to six days. Sour rot incidence in wounded berries inoculated with yeast-bacterium associations resulted higher than in berries inoculated with one single NSY or AAB strain. Among all NSY-AAB associations, the yeast-bacterium association composed of Candida zemplinina CBS 9494 (Cz) and Acetobacter syzygii LMG 21419 (As) showed the highest prevalence of sour rot; thus, after preliminary in vitro assays, this simplified As-Cz microbial consortium was inoculated in wounded berries that were stored at 4 °C for ten days under ozone (2.14 mg m -3 ) or in air. At the end of cold storage, no berries showed sour-rot symptoms although ozonation mainly affected As viable cell count. After additional 12 days at 25 °C, the sour rot index of inoculated As-Cz berries previously cold-stored under ozone or in air accounted for 22.6 ± 3.7% and 66.7 ± 4.5%, respectively. Molecular analyses of dominant AAB and NSY populations of both sound and rotten berries during post-refrigeration period revealed the appearance of new strains mainly belonging to Gluconobacter albidus and Hanseniaspora uvarum species, respectively. Cold ozonation resulted an effective approach to extend the shelf-life of table grapes also after cold storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Selection of aggressive pathogenic and solopathogenic strains of Ustilago maydis to improve Huitlacoche production

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    Porfirio Raúl Galicia-García

    Full Text Available ABSTRACT Ustilago maydis is a basidiomycete known as the causative agent of 'common smut', worldwide disease of maize that is recognized by the galls it forms, which have considerable potential as a gourmet food. Results of infection are quite variable, even under optimal greenhouse conditions. In order to find pathogenic strains able to be used as a highly infective and stable inoculum for the successful production of galls either in greenhouses or in the field, ears with gall symptoms containing teliospores were recovered from maize plants. The teliospores were suspended in water and plated on nutrient-rich medium. Twenty-six colonies developed, containing three types of yeast-like colonies: saprotrophic, pathogenic, and solopathogenic. DAPI staining confirmed the presence of solopathogenic strains with diploid sporidia. Groups of different mating types were found when pairs of the 26 strains were arranged resembling partial-diallel combinations. Amplification of the partial b locus revealed that the strains found harbor the alleles b3 and b4, allowing the formation in dikaryotic strains of heterodimeric regulatory proteins associated with fungal development and pathogenicity. In this study, we isolated compatible haploid and solopathogenic diploid strains for their high capacity for inducing smut.

  9. Epidemiological Features and Trends of Brown Spot of Pear Disease Based on the Diversity of Pathogen Populations and Climate Change Effects.

    Science.gov (United States)

    Moragrega, Concepció; Puig, Mireia; Ruz, Lídia; Montesinos, Emilio; Llorente, Isidre

    2018-02-01

    Brown spot of pear, caused by the fungus Stemphylium vesicarium, is an emerging disease of economic importance in several pear-growing areas in Europe. In recent years, new control strategies combining sanitation practices and fungicide applications according to developed forecasting models have been introduced to manage the disease. However, the pathogenic and saprophytic behavior of this pathogen makes it difficult to manage the disease. In addition, climate change can also result in variations in the severity and geographical distribution of the disease. In this study, ecological and epidemiological aspects of brown spot of pear disease related to inoculum characterization and climate change impact were elucidated. The pathogenic variation in S. vesicarium populations from pear orchards and its relationship to inoculum sources (air samples, leaf debris, and infected host and nonhost tissues) was determined using multivariate analysis. In total, six variables related to infection and disease development on cultivar Conference pear detached leaves of 110 S. vesicarium isolates were analyzed. A high proportion of isolates (42%) were nonpathogenic to pear; 85% of these nonpathogenic isolates were recovered from air samples. Most isolates recovered from lesions (93%) and pseudothecia (83%) were pathogenic to pear. A group of pathogenic isolates rapidly infected cultivar Conference pear leaves resulted in disease increase that followed a monomolecular model, whereas some S. vesicarium isolates required a period of time after inoculation to initiate infection and resulted in disease increase that followed a logistic model. The latter group was mainly composed of isolates recovered from pseudothecia on leaf debris, whereas the former group was mainly composed of isolates recovered from lesions on pear fruit and leaves. The relationship between the source of inoculum and pathogenic/aggressiveness profile was confirmed by principal component analysis. The effect of

  10. Pathogenic mycoflora on carrot seeds

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    Bogdan Nowicki

    2013-12-01

    Full Text Available Altogether 300 seed samples were collected during 9 years in 8 regions of Poland and the fungi Were isolated and their pathogenicity to carrot seedlings was examined. Alternaria rudicina provcd to be the most important pathogen although. A. alternata was more common. The other important pathogens were Fusarium spp., Phoma spp. and Botrytis cinerea. The infection of carrot seeds by A. radicina should be used as an important criterium in seed quality evaluation.

  11. Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation.

    Science.gov (United States)

    Birch, Heidi; Hammershøj, Rikke; Comber, Mike; Mayer, Philipp

    2017-10-01

    Biodegradation is a dominant removal process for many organic pollutants, and biodegradation tests serve as tools for assessing their environmental fate within regulatory risk assessment. In simulation tests, the inoculum is not standardized, varying in microbial quantity and quality, thereby potentially impacting the observed biodegradation kinetics. In this study we investigated the effect of inoculum origin on the biodegradation kinetics of hydrocarbons for five inocula from surface waters varying in urbanization and thus expected pre-exposure to petroleum hydrocarbons. A new biodegradation method for testing mixtures of hydrophobic chemicals at trace concentrations was demonstrated: Aqueous solutions containing 9 hydrocarbons were generated by passive dosing and diluted with surface water resulting in test systems containing native microorganisms exposed to test substances at ng-μg/L levels. Automated Headspace Solid Phase Microextraction coupled to GC-MS was applied directly to these test systems to determine substrate depletion relative to abiotic controls. Lag phases were generally less than 8 days. First order rate constants were within one order of magnitude for each hydrocarbon in four of the five waters but lower in water from a rural lake. The sequence of degradation between the 9 hydrocarbons showed similar patterns in the five waters indicating the potential for using selected hydrocarbons for benchmarking between biodegradation tests. Degradation half-times were shorter than or within one order of magnitude of BioHCwin predictions for 8 of 9 hydrocarbons. These results showed that location choice is important for biodegradation kinetics and can provide a relevant input to aquatic exposure and fate models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Batch, design optimization, and DNA sequencing study for continuous 1,3-propanediol production from waste glycerol by a soil-based inoculum.

    Science.gov (United States)

    Kanjilal, Baishali; Noshadi, Iman; Bautista, Eddy J; Srivastava, Ranjan; Parnas, Richard S

    2015-03-01

    1,3-propanediol (1,3-PD) was produced with a robust fermentation process using waste glycerol feedstock from biodiesel production and a soil-based bacterial inoculum. An iterative inoculation method was developed to achieve independence from soil and selectively breed bacterial populations capable of glycerol metabolism to 1,3-PD. The inoculum showed high resistance to impurities in the feedstock. 1,3-PD selectivity and yield in batch fermentations was optimized by appropriate nutrient compositions and pH control. The batch yield of 1,3-PD was maximized to ~0.7 mol/mol for industrial glycerol which was higher than that for pure glycerin. 16S rDNA sequencing results show a systematic selective enrichment of 1,3-PD producing bacteria with iterative inoculation and subsequent process control. A statistical design of experiments was carried out on industrial glycerol batches to optimize conditions, which were used to run two continuous flow stirred-tank reactor (CSTR) experiments over a period of >500 h each. A detailed analysis of steady states at three dilution rates is presented. Enhanced specific 1,3-PD productivity was observed with faster dilution rates due to lower levels of solvent degeneration. 1,3-PD productivity, specific productivity, and yield of 1.1 g/l hr, 1.5 g/g hr, and 0.6 mol/mol of glycerol were obtained at a dilution rate of 0.1 h(-1)which is bettered only by pure strains in pure glycerin feeds.

  13. Inoculum effect of high concentrations of methicillin-susceptible Staphylococcus aureus on the efficacy of cefazolin and other beta-lactams.

    Science.gov (United States)

    Saeki, Masachika; Shinagawa, Masaaki; Yakuwa, Yuki; Nirasawa, Shinya; Sato, Yuki; Yanagihara, Nozomi; Takahashi, Satoshi

    2018-03-01

    The existence of a cefazolin inoculum effect (InE) of methicillin-susceptible Staphylococcus aureus (MSSA), which is speculated to be a reason for cefazolin treatment failure in MSSA infections, is controversial. In Japan, although cefazolin is one of the therapeutic choices for patients with MSSA infection, there are few reports of this effect. Additionally, the association between InE and blaZ type in beta-lactams other than cefazolin has not been well documented. In this study, we confirmed an MSSA InE in several beta-lactams, including cefazolin, and its relationship with blaZ, using 52 MSSA isolates from blood cultures. Three isolates (5.8%) that possessed type A blaZ showed a pronounced cefazolin InE. Five isolates (9.6%) showed pronounced InE with sulbactam/ampicillin; four isolates had type C blaZ and one had type A blaZ. However, we confirmed InE in MSSA isolates with blaZ not only type A and C but also B and D. For cefotaxime, ceftriaxone, imipenem, and meropenem, regardless of the presence of blaZ, we did not observe a significant increase in MICs at a high inoculum of MSSA. Hence, our results suggest that the above four beta-lactams are good alternatives to cefazolin if InE leads to treatment failure in a patient. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  14. Redução do inóculo inicial de Sclerotinia sclerotiorum em soja cultivada após uso do sistema Santa Fé Reduction of Sclerotinia sclerotiorum initial inoculum in soybean grown after the use of the Santa Fé system

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    Claudia Adriana Görgen

    2010-10-01

    Full Text Available O objetivo deste trabalho foi avaliar a efetividade do sistema Santa Fé na redução do inóculo inicial de Sclerotinia sclerotiorum, agente causal do mofo-branco em soja. O experimento foi realizado em Jataí, GO, nas safras de 2007/2008, 2008/2009 e 2009/2010, em lavoura comercial infestada naturalmente pelo patógeno. Foram feitas avaliações quanto ao número de escleródios germinados na superfície do solo, e quanto ao número de apotécios e estipes do patógeno. Utilizou-se o delineamento experimental de blocos ao acaso, em arranjo fatorial (2x4, com quatro repetições. Os tratamentos consistiram do sistema Santa Fé (milho + Urochloa ruziziensis e do milho solteiro implantados na safrinha, em março de 2008 e 2009. Além disso, estudaram-se também quatro diferentes épocas de avaliação da germinação dos escleródios e produção de apotécios e estipes. Verificou-se que o sistema Santa Fé aumentou a proporção de escleródios menores que 2 mm, considerados de menor infectividade, e favoreceu a redução do inóculo inicial por meio da germinação de escleródios e formação de apotécios na entressafra, o que reduziu o número de escleródios germinados e o número de apotécios em pleno florescimento durante os cultivos da soja. O sistema Santa Fé pode reduzir o inóculo inicial de S. sclerotiorum, e pode ser utilizado no manejo do mofo-branco da soja.The objective of this work was to evaluate the effectiveness of Santa Fé system on reduction of the initial inoculum of Sclerotinia sclerotiorum, the causal agent of white mold in soybean. The experiment was carried out in Jataí, GO, Brazil, during 2007/2008, 2008/2009 and 2009/2010 growing seasons, in a commercial field naturally infested with the pathogen. Evaluations were done for number of sclerodia germinated on the soil surface, and for the pathogen number of apothecia and stipes. The experimental design was a randomized block, in a 2x4 factorial arrangement with four

  15. Rapid detection of pathogenic bacteria by volatile organic compound (VOC) analysis

    Science.gov (United States)

    Senecal, Andre G.; Magnone, Joshua; Yeomans, Walter; Powers, Edmund M.

    2002-02-01

    Developments in rapid detection technologies have made countless improvements over the years. However, because of the limited sample that these technologies can process in a single run, the chance of capturing and identifying a small amount of pathogens is difficult. The problem is further magnified by the natural random distribution of pathogens in foods. Methods to simplify pathogenic detection through the identification of bacteria specific VOC were studied. E. coli O157:H7 and Salmonella typhimurium were grown on selected agar medium to model protein, and carbohydrate based foods. Pathogenic and common spoilage bacteria (Pseudomonas and Morexella) were screened for unique VOC production. Bacteria were grown on agar slants in closed vials. Headspace sampling was performed at intervals up to 24 hours using Solid Phase Micro-Extraction (SPME) techniques followed by GC/MS analysis. Development of unique volatiles was followed to establish sensitivity of detection. E. coli produced VOC not found in either Trypticase Soy Yeast (TSY) agar blanks or spoilage organism samples were - indole, 1-decanol, and 2-nonanone. Salmonella specific VOC grown on TSY were 3-methyl-1-butanol, dimethyl sulfide, 2-undecanol, 2-pentadecanol and 1-octanol. Trials on potato dextrose agar (PDA) slants indicated VOC specific for E. coli and Salmonella when compared to PDA blanks and Pseudomonas samples. However, these VOC peaks were similar for both pathogens. Morexella did not grow on PDA slants. Work will continue with model growth mediums at various temperatures, and mixed flora inoculums. As well as, VOC production based on the dynamics of bacterial growth.

  16. Effect of postharvest application of ethylene on phenolic acids and anthocyanins profile in three blueberry cultivars (Vaccinium corymbosum).

    Science.gov (United States)

    Costa, Daniela V T A; de Almeida, Domingos P F; Pintado, Manuela

    2018-03-30

    Blueberry is a fruit that has been extensively studied for its health benefits, mainly due to its high antioxidant activity. There are a high correlation between antioxidant activity and total anthocyanins and phenolic compounds. The postharvest treatment using ethylene may be a factor affecting the anthocyanins content. The objective of this work was to analyze the postharvest treatment using ethylene on the anthocyanins profile during the storage of blueberries and phytochemical composition of 'Bluecrop', 'Goldtraube' and 'Ozarkblue'. Fruits were harvested at commercial maturity; the treatment was carried out with 1000 μL L -1 of ethylene for 24 h followed by storage at 4 °C under normal atmosphere for 56 d. One day after treatment with ethylene, this increased seven (more than 45%) and four (more than 65%) of the nine anthocyanins identified in the cultivars Bluecrop, Goldtraube respectively, and decreased five of the seven anthocyanins identified in 'Ozarkblue'. For 'Bluecrop' however this increase was reduced until the end of storage but in 'Goldtraube' seven anthocyanins had increased. The effect of ethylene on anthocyanin composition appeared to depend on the cultivar. 'Bluecrop' and 'Goldtraube' responded positively with increase on total anthocyanins. This article is protected by copyright. All rights reserved.

  17. Fumigation characteristics of ozone in postharvest treatment of Kabkab dates (Phoenix dactylifera L.) against selected insect infestation.

    Science.gov (United States)

    Niakousari, Mehrdad; Erjaee, Zahra; Javadian, Shahram

    2010-04-01

    Methyl bromide fumigation, the most accepted quarantine treatment for dates and many other dried commodities, will be phased out by 2015 worldwide. As a result, there is a critical need to develop durable alternatives for methyl bromide as postharvest treatments of agricultural commodities. This article presents a new method for postharvest treatment of Kabkab dates (Phoenix dactylifera L.) by application of gaseous ozone to reduce or eliminate all life stages (adults, larvae, and eggs) of Indian meal moth (Plodia interpunctella) and sawtooth grain beetle (Oryzaephilus surinamensis). The effect of the ozonation process on the sugar content of dates was also evaluated. Infested dates were exposed to ozone concentrations of 600, 1,200, 2,000, and 4,000 ppm for 1 and 2 h. As insect eggs are known to be most tolerant to many chemical or physical treatments, they were additionally exposed to an atmosphere of pure carbon dioxide prior to ozonation. Exposing samples to ozone concentrations of >2,000 ppm for 2 h resulted in complete mortality of larvae and adults. Exposure to 4,000 ppm of ozone for 2 h resulted in 80% mortality of eggs, and exposure to CO(2) prior to ozonation did not improve the effect of ozonation on eggs. Ozone did not have any influence on the sugar content of Kabkab dates.

  18. Dissipation and Migration of Pyrethroids in Auricularia polytricha Mont. from Cultivation to Postharvest Processing and Dietary Risk

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    Jin-Jing Xiao

    2018-03-01

    Full Text Available In order to ensure raw consumption safety the dissipation behavior, migration, postharvest processing, and dietary risk assessment of five pyrethroids in mushroom (Auricularia polytricha Mont. cultivated under Chinese greenhouse-field conditions. Half-lives (t1/2 of pyrethroids in fruiting body and substrate samples were 3.10–5.26 and 17.46–40.06 d, respectively. Fenpropathrin dissipated rapidly in fruiting bodies (t1/2 3.10 d; bifenthrin had the longest t1/2. At harvest, pyrethroid residues in A. polytricha (except fenpropathrin were above the respective maximum residue limits (MRLs. Some migration of lambda-cyhalothrin was observed in the substrate-fruit body system. In postharvest-processing, sun-drying and soaking reduced pyrethroid residues by 25–83%. We therefore recommend that consumers soak these mushrooms in 0.5% NaHCO3 at 50 °C for 90 min. Pyrethroids exhibit a particularly low PF value of 0.08–0.13%, resulting in a negligible exposure risk upon mushroom consumption. This study provides guidance for the safe application of pyrethroids to edible fungi, and for the establishment of MRLs in mushrooms to reduce pesticide exposure in humans.

  19. Effect of different coatings on post-harvest quality and bioactive compounds of pomegranate (Punica granatum L.) fruits.

    Science.gov (United States)

    Meighani, Hossein; Ghasemnezhad, Mahmood; Bakhshi, Davood

    2015-07-01

    The effect of three different coatings; resin wax (Britex Ti), carnauba wax (Xedasol M14), and chitosan (1 and 2 % w/v) on postharvest quality of pomegranate fruits were investigated. Fruits quality characteristics and bioactive compounds were evaluated during 40, 80 and 120 days storage at 4.5 °C and 3 additional days at 20 °C. The results showed that uncoated fruits showed higher respiration rate, weight loss, L* and b* values of arils, total soluble solids (TSS)/titratable acidity (TA), and pH than coated fruits during storage. Coating treatments could delay declining TSS and TA percent, a* value of arils, as well as bioactive compounds such as total phenolics, flavonoids and anthocyanins content and antioxidant activity. The coated fruits with commercial resin and carnauba waxes showed significantly lower respiration rate and weight loss than other treatments, however carnauba wax could maintain considerably higher fruits quality and bioactive compounds than other coating treatments. The results suggested that postharvest application of carnauba wax have a potential to extend storage life of pomegranate fruits by reducing respiration rate, water loss and maintaining fruit quality.

  20. Post-Harvest Induced Production of Salvianolic Acids and Significant Promotion of Antioxidant Properties in Roots of Salvia miltiorrhiza (Danshen

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    Guo-Jun Zhou

    2014-05-01

    Full Text Available Danshen, the dried roots of Salvia miltiorrhiza, is an extremely valued Traditional Chinese Medicine. Previously, we have demonstrated that salvianolic acid B (SaB, the important bioactive ingredient in this herb, was a post-harvest product. Here, we further reported that all salvianolic acids (SAs in the roots were post-harvest products of the drying process. In addition, the results of various radical scavenging activity assays, including lipid peroxidation (1, DPPH (2, hydroxyl (3 and superoxide (4, were significantly increased along with the accumulation of total salvianolic acids in the process. The contents of chemical targets and antioxidant activities both reached the highest value under thermal treatment at 130 °C for 80 min. In this dehydration period, contents of SaB, and sum of nine SAs increased from 0.01% to 5.51%, and 0.20% to 6.61%; and IC50 of antioxidant activity decreased from 4.85 to 2.69 (1; 7.75 to 0.43 (2; 2.57 to 1.13 (3 and 17.25 to 1.10 mg/mL. These results further supported the hypothesis that the newly harvested plant roots were still physiologically active and the secondary metabolites might be produced due to dehydration stress after harvest. Our findings supplied an important and useful theoretical basis for promoting the quality of Danshen and other medicinal plant materials.

  1. Effect of hydrocooling, packaging, and cold storage on the post-harvest quality of peppermint (Mentha piperita L.

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    C.K.R. BARBOSA

    2016-01-01

    Full Text Available ABSTRACT The purpose of this study was to assess the effects of hydrocooling and polyethylene terephthalate (PET perforated and non-perforated packaging on post-harvest quality of peppermint (Mentha piperita L. leaves stored at 5 and 25ºC. The experiments were conducted using a subdivided parcel layout in a completely randomized design with four replicates. Each parcel used a 2x3 layout (two hydrocooling treatments and three packaging treatments with subparcels for storage time. The shelf life, chlorophyll content, mass loss (ML, relative water content (RWC, total soluble sugars (TSS, reducing sugars (Red, non-reducing sugars (NRed and starch of the leaves were determined. Cold storage increased the shelf life of the peppermint by up to 64 times (>15 days. Hydrocooling increased the RWC of the leaves. Plastic packaging was effective in maintaining the RWC. Unperforated packages more effectively prevented ML in the peppermint leaves and prevented the leaves from wilting for a longer period of time. The chlorophyll content of the leaves varied according to the treatment. The soluble sugars and starch levels varied according to RWC. Hydrocooling with the use of non-perforated plastic packages was the most effective method for maintaining the postharvest quality of the peppermint.

  2. Study on freshness quality and post-harvest loss of Hilsa (Tenualosa Ilisha during marketing in Mymensingh town, Bangladesh

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    Dilip Chandra Ray

    2015-08-01

    Full Text Available An investigation was conducted to know the freshness quality and associated post-harvest loss of hilsa, if any, transported to Mymensingh from the major landing centers through Cox’s Bazar-Chittagong (route A and Barguna-Chandpur (route B routes for a period of July to October 2012. The average environmental temperature of the wholesale and retail markets was 30.7 °C and 30.6 °C where the body temperature of hilsa was 4.5 °C (route A and 4.7 °C (route B, respectively. The Freshness quality of hilsa was assessed using sensory defects points (DPs that eventually gave rise to numerical values ‘1’ being the freshest and ‘5’ being the worst quality. The DPs of hilsa were found 2.0, which reveal that the fishes were in excellent conditions, i.e., there was no significant post-harvest loss even during retail sale. DPs on arrival and at wholesale in July, September and October were significantly different after auction and during retail sale (p<0.05, and in August differed significantly only during retail sale (p<0.05. It was observed that hilsa transported to Mymensingh from Barguna-Chandpur were better in quality than those transported from Cox’s Bazar-Chittagong. The reason behind this finding was not studied and this needs to be elucidated through further research.

  3. Chloride stress triggers maturation and negatively affects the postharvest quality of persimmon fruit. Involvement of calyx ethylene production.

    Science.gov (United States)

    Besada, Cristina; Gil, Rebeca; Bonet, Luis; Quiñones, Ana; Intrigliolo, Diego; Salvador, Alejandra

    2016-03-01

    In recent years many hectares planted with persimmon trees in E Spain have been diagnosed with chloride toxicity. An effect of this abiotic stress on fruit quality has been reported in different crops. However, the impact of chloride stress on persimmon fruit quality is unknown. The harvest and postharvest quality of persimmons harvested from trees that manifest different intensities of chloride toxicity foliar symptoms was evaluated herein. Our results revealed that fruits from trees under chloride stress conditions underwent chloride accumulation in the calyx, which was more marked the greater the salt stress intensity trees were exposed to. Increased chloride concentrations in the calyx stimulated ethylene production in this tissue. In the fruits affected by slight and moderate chloride stress, calyx ethylene production accelerated the maturity process, as reflected by increased fruit colour and diminished fruit firmness. In the fruits under severe chloride stress, the high ethylene levels in the calyx triggered autocatalytic ethylene production in other fruit tissues, which led fruit maturity to drastically advance. In these fruits effectiveness of CO2 deastringency treatment was not complete and fruit softening enhanced during the postharvest period. Moreover, chloride stress conditions had a marked effect on reducing fruit weight, even in slightly stressed trees. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Combination of UV-C treatment and Metschnikowia pulcherrimas for controlling Alternaria rot in postharvest winter jujube fruit.

    Science.gov (United States)

    Guo, Dongqi; Zhu, Lixia; Hou, Xujie

    2015-01-01

    The potential of using antagonistic yeast Metschnikowia pulcherrimas alone or in combination with ultraviolet-C (UV-C) treatment for controlling Alternaria rot of winter jujube, and its effects on postharvest quality of fruit was investigated. The results showed that spore germination of Alternaria alternata was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m(-2) ) in vitro. In vivo, UV-C treatment (5 kJ m(-2) ) or antagonist yeast was capable of reducing the percentage of infected wounds and lesion diameter in artificially inoculated jujube fruits, however, in fruit treated with combination of UV-C treatment and M. pulcherrima, the percentage of infected wounds and lesion diameter was only 16.0% and 0.60 cm, respectively. The decay incidence on winter jujube fruits treated with the combination of UV-C treatment and M. pulcherrima was 23% after storage at 0 ± 1 °C for 45 d followed by 22 °C for 7 d. None of the treatments impaired quality parameters of jujube fruit. Thus, the combination of UV-C radiation and M. pulcherrima could be an alternative to synthetic fungicides for controlling postharvest Alternaria rot of winter jujube. © 2014 Institute of Food Technologists®

  5. Pathogenic agents in freshwater resources

    Science.gov (United States)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  6. Comparative proteomic analysis of pathogenic and non-pathogenic strains from the swine pathogen Mycoplasma hyopneumoniae

    Directory of Open Access Journals (Sweden)

    Klein Cátia S

    2009-12-01

    Full Text Available Abstract Background Mycoplasma hyopneumoniae is a highly infectious swine pathogen and is the causative agent of enzootic pneumonia (EP. Following the previous report of a proteomic survey of the pathogenic 7448 strain of swine pathogen, Mycoplasma hyopneumoniae, we performed comparative protein profiling of three M. hyopneumoniae strains, namely the non-pathogenic J strain and the two pathogenic strains 7448 and 7422. Results In 2DE comparisons, we were able to identify differences in expression levels for 67 proteins, including the overexpression of some cytoadherence-related proteins only in the pathogenic strains. 2DE immunoblot analyses allowed the identification of differential proteolytic cleavage patterns of the P97 adhesin in the three strains. For more comprehensive protein profiling, an LC-MS/MS strategy was used. Overall, 35% of the M. hyopneumoniae genome coding capacity was covered. Partially overlapping profiles of identified proteins were observed in the strains with 81 proteins identified only in one strain and 54 proteins identified in two strains. Abundance analysis of proteins detected in more than one strain demonstrates the relative overexpression of 64 proteins, including the P97 adhesin in the pathogenic strains. Conclusions Our results indicate the physiological differences between the non-pathogenic strain, with its non-infective proliferate lifestyle, and the pathogenic strains, with its constitutive expression of adhesins, which would render the bacterium competent for adhesion and infection prior to host contact.

  7. Postharvest and sensory evaluation of selected ‘Hass’x‘Bacon’ and ‘Bacon’x ‘Hass’ avocado hybrids grown in East-Central Florida

    Science.gov (United States)

    Avocado (Persea americana Mill.) is a high-value fruit that continues to increase in consumer demand. A population of ‘Hass’-‘Bacon’ hybrids was planted at USDA-ARS, Fort Pierce as part of a study to find selections with good horticultural and postharvest quality traits for Florida. Extensive phenot...

  8. Effect of methyl salicylate in combination with 1-methylcyclopropene on postharvest quality and decay caused by Botrytis cinerea in tomato fruit.

    Science.gov (United States)

    Min, Dedong; Li, Fujun; Zhang, Xinhua; Shu, Pan; Cui, Xixi; Dong, Lulu; Ren, Chuntao; Meng, Demei; Li, Jian

    2018-01-20

    Postharvest diseases result in major losses in fruits. Tomato is susceptible to postharvest rot caused by Botrytis cinerea and is regarded as a good model system to study postharvest disease and quality deterioration in fruit. To develop a safe and effective technique to alleviate disease and maintain fruit quality, the effects of methyl salicylate (MeSA) and 1-methylcyclopropene (1-MCP) either separately or combined on quality and gray mold caused by B. cinerea in tomato fruit were investigated. The results showed that application of MeSA (0.05 mmol L -1 ) delayed fruit ripening and reduced gray mold. Compared with MeSA treatment, 1-MCP (0.5 µL L -1 ) effectively delayed fruit ripening. Further, MeSA combined with 1-MCP treatment was more effective in inhibiting fungal decay during storage than MeSA treatment alone. The combined treatment not only enhanced pathogenesis-related protein 1 (PR1) expression, activities of defense enzymes and total phenolic content but also inhibited the increase in electrical conductivity and malondialdehyde content. The combined treatment was also more effective in retaining firmness, color change and titratable acidity content than MeSA treatment alone. MeSA combined with 1-MCP treatment was a useful technique to maintain quality and alleviate gray mold in postharvest tomato fruit during storage. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  9. Use of bacillus subtilis strains to inhibit postharvest pathogenic fungi; Attivita` antagonista di alcuni ceppi di bacillus subtilis nei confronti di funghi patogeni

    Energy Technology Data Exchange (ETDEWEB)

    Arras, G.; Gambella, F.; Demontis, S.; Petretto, A.

    1995-09-01

    An isolate (87) of the bacillus subtilis strains isolated from cold stored citrus fruit 13 proved to inhibit the growth in vitro of the penicillium italicum used in the experiment (from 50.6% to 92.2%) and to inhibit botrytis cinerea (from 65.3% to 95.9%). A further test, superimposing on plates containing PDA strains Nos. 13, 173, and 160, totally inhibited the fungi. Tested in vivo on artificially bruised oranges, they significantly inhibited two fungi.

  10. IMPROVING POSTHARVEST VASE-LIFE AND QUALITY OF CUT GERBERA FLOWERS USING NATURAL AND CHEMICAL PRESERVATIVES

    Directory of Open Access Journals (Sweden)

    Mehrdad Jafarpour

    2015-06-01

    Full Text Available Gerbera is one of ten popular cut flowers in the world which occupies the forth place according to the global trends in floriculture. Hence, this study aimed to investigate the effects of chemical, hormonal and essential oil substances in preservative solutions to improve its postharvest qualitative characteristics. Two pulse treatments including distilled water (pulse1 and 4% CaCl2 + 3% sucrose (pulse2 for 24 hour were applied before long-time treatments. Long-time treatments were comprised of (1 Hormonal treatments: 0, 25, 30 mg*l-1 Gibberellic acid, 0, 150, 250 mg*l-1 Benzyl adenine and 0, 100, 200 mg*l-1 5-Sulfosalicylic acid (2 Chemical treatments: 0, 0.4, 0.8 mM Silver thiosulphate, 0, 5, 10 mg*l-1 Nano-silver particles, 0, 4, 6 mM Aminooxy acetic acid and 0, 200 and 400 mg*l-1 8-hydroxyquinoline sulphate (3 Essential oils: Thymus essential oil and Stevia essential oils (0, 0.1 and 0.2 mg*l-1. Data were subjected to analysis of variance based on the factorial experiment model in the layout completely randomized design. Mean comparison was performed using the Duncan’s multiple range test. Parameters of fresh weight, stem bending, capitulum diameter, carotenoid pigments of petal and vase-life longevity were evaluated during 12 days. The highest fresh weight was obtained when cut flowers were held in a solution containing pulse1 + 250 mg*l-1 BA. Among all treatments, 8-HQS treatment showed the best effects on preventing stem bending, increasing capitulum diameter and also on prolonging of vase-life, but nonetheless, the effects of pulse treatments and 8-HQS concentrations were insignificant. To conclude, 200 mg*l-1 8-HQS without pulse treatment has the potential to be used as a commercial preservative solution to improve the keeping quality and vase-life of this important cut flower.

  11. Inactivation of bacterial pathogens in yoba mutandabota, a dairy product fermented with the probiotic Lactobacillus rhamnosus yoba.

    Science.gov (United States)

    Mpofu, Augustine; Linnemann, Anita R; Nout, Martinus J R; Zwietering, Marcel H; Smid, Eddy J; den Besten, Heidy M W

    2016-01-18

    Mutandabota is a dairy product consumed as a major source of proteins and micronutrients in Southern Africa. In this study the microbial safety of traditional and a variant of mutandabota fermented with the probiotic Lactobacillus rhamnosus yoba (yoba mutandabota) was investigated by challenging the products with five important food pathogens: Listeria monocytogenes, Salmonella spp., Campylobacter jejuni, Escherichia coli O157:H7 and Bacillus cereus. Pasteurized full-fat cow's milk was used for producing traditional and yoba mutandabota, and was inoculated with a cocktail of strains of the pathogens at an inoculum level of 5.5 log cfu/mL. Survival of the pathogens was monitored over a potential consumption time of 24h for traditional mutandabota, and over 24h of fermentation followed by 24h of potential consumption time for yoba mutandabota. In traditional mutandabota (pH3.4 ± 0.1) no viable cells of B. cereus and C. jejuni were detected 3h after inoculation, while L. monocytogenes, E. coli O157:H7 and Salmonella spp. significantly declined (Pfermentation, mainly due to organic acids produced during fermentation. Only Salmonella spp. was able to grow in yoba mutandabota during the first 9h of fermentation, but then decreased in viable plate count. None of the tested pathogens were detected (>3.5 log inactivation) after 3h into potential consumption time of yoba mutandabota. Inactivation of pathogens in mutandabota is of public health significance because food-borne pathogens endanger public health upon consumption of contaminated food, especially in Southern Africa where there are many vulnerable consumers of mutandabota such as children, elderly and immuno-compromised people with HIV/AIDS. The findings of this study demonstrate that mutandabota fermented with L. rhamnosus yoba has antimicrobial properties against the tested pathogens and it is safer compared to the traditional mutandabota. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Effects of Ethanolic Ferolagu angulata Extract on Pathogenic Gastrointestinal Bacteria and Probiotic Bacteria in Skimmed Milk Medium

    Directory of Open Access Journals (Sweden)

    Reza Naghiha

    2016-12-01

    Full Text Available Background:    Due to excessive consumption of synthetic drugs, drug resistance rate of pathogenic bacteria is increasing and there is an ever-increasing need to find new safe compounds to tackle this problem. This study was conducted to investigate the consequences of chavill extract on the growth and viability of gastrointestinal pathogenic bacterium and probiotics bacteria. Methods:    The experiment contained three levels of the chavill extract concentrations (0, 1 and 3% which were added to the milk free fat in accompany with three probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei and lactobacillus plantaram and a pathogenic gastrointestinal bacterium (Salmonella typhimurium. Bacterial inoculums (1×107 CFU/ml with different concentrations of chavill extract were added to skimmed milk medium and bacteria growth were enumerated. Results:  The concentration of 1% chavill extract significantly increased the total count of probiotic bacteria compared to the control group, while the number of pathogenic bacteria was decreased. At 3% chavill extract the growth of Lactobacillus acidophilus and Lactobacillus plantaram were increased. On the other hand, it prevented the growth of Salmonella typhimurium Conclusion:   Chavill extracts would play as an alternative to antibiotics in pharmacological studies to decreases harmful bacteria and increase probiotic bacteria.

  13. Óleos essenciais no controle pós-colheita de Colletotrichum gloeosporioides em mamão Essential oils on postharvest control of Colletotrichum gloeosporioides in papaya fruit

    Directory of Open Access Journals (Sweden)

    P.R. Carnelossi

    2009-01-01

    Full Text Available Os subprodutos de plantas medicinais têm sido estudados como uma alternativa para o controle de doenças de plantas visando amenizar e/ou reduzir o uso abusivo de agrotóxicos, principalmente em condições pós-colheita. Assim, este trabalho teve como objetivo avaliar, in vitro e in vivo, o controle de Colletotrichum gloeosporioides, agente causal da antracnose do mamão em pós-colheita, por óleos essenciais (OEs de Cymbopogon citratus, Eucalyptus citriodora, Mentha arvensis e Artemisia dracunculus. Para inibição do crescimento micelial in vitro, os OEs foram incorporados ao BDA (Batata-dextrose-ágar tendo-se observado a inibição total ou parcial do crescimento micelial e da esporulação deste fitopatógeno, dependendo do óleo essencial utilizado. No ensaio in vivo utilizaram-se os OEs de C. citratus (1% e E. citriodora (1%. A inoculação com o fitopatógeno foi concomitante e 24 h após os tratamentos alternativos, que foram: óleos essenciais de C. citratus e de E. citriodora (1% e biomassa cítrica (150 mL 100 L-1 (Ecolife®. Os parâmetros avaliados foram severidade da doença, redução da massa, diâmetro, comprimento final dos frutos, pH e a concentração de sólidos solúveis totais (ºBrix. Pode-se observar que, no controle da doença, os frutos tratados e imediatamente inoculados com o fitopatógenos apresentaram maior AACPD (Área Abaixo da Curva do Progresso da Doença. Porém, frutos tratados e inoculados 24 h após os tratamentos apresentaram maior controle da doença, confirmando o potencial dos óleos essenciais testados no presente trabalho.The products from medicinal plants have been studied as an alternative in the control of plant diseases in order to mitigate and / or reduce pesticide abuse mainly in postharvest. Thus, the present study aimed to evaluate, in vitro and in vivo, the control of Colletotrichum gloeosporioides, the causative agent of papaya anthracnose, in postharvest using essential oils (EOs of

  14. Transient virulence of emerging pathogens.

    Science.gov (United States)

    Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

    2010-05-06

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

  15. Ecological niche of plant pathogens

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    Ecaterina Fodor

    2011-06-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread. 

  16. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-02-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.

  17. Simulating the environmental performance of post-harvest management measures to comply with the EU Nitrates Directive.

    Science.gov (United States)

    De Waele, J; D'Haene, K; Salomez, J; Hofman, G; De Neve, S

    2017-02-01

    Nitrate (NO 3 - ) leaching from farmland remains the predominant source of nitrogen (N) loads to European ground- and surface water. As soil mineral N content at harvest is often high and may increase by mineralisation from crop residues and soil organic matter, it is critical to understand which post-harvest management measures can be taken to restrict the average NO 3 - concentration in ground- and surface waters below the norm of 50 mg l -1 . Nitrate leaching was simulated with the EU-rotate_N model on a silty and a sandy soil following the five main arable crops cultivated in Flanders: cut grassland, silage maize, potatoes, sugar beets and winter wheat, in scenarios of optimum fertilisation with and without post-harvest measures. We compared the average NO 3 - concentration in the leaching water at a depth of 90 cm in these scenarios after dividing it by a factor of 2.1 to include natural attenuation processes occurring during transport towards ground- and surface water. For cut grassland, the average attenuated NO 3 - concentration remained below the norm on both soils. In order to comply with the Nitrates Directive, post-harvest measures seemed to be necessary on sandy soils for the four other crops and on silty soils for silage maize and for potatoes. Successful measures appeared to be the early sowing of winter crops after harvesting winter wheat, the undersowing of grass in silage maize and the removal of sugar beet leaves. Potatoes remained a problematic crop as N uptake by winter crops was insufficient to prevent excessive NO 3 - leaching. For each crop, maximum levels of soil mineral N content at harvest were proposed, both with and without additional measures, which could be used in future nutrient legislation. The approach taken here could be upscaled from the field level to the subcatchment level to see how different crops could be arranged within a subcatchment to permit the cultivation of problem crops without adversely affecting the water

  18. Proteomics and transcriptomics of broccoli subjected to exogenously supplied and transgenic senescence-induced cytokinin for amelioration of postharvest yellowing.

    Science.gov (United States)

    Liu, Mao-Sen; Li, Hui-Chun; Lai, Ying-Mi; Lo, Hsiao-Feng; Chen, Long-Fang O

    2013-11-20

    Previously, we investigated transgenic broccoli harboring senescence-associated-gene (SAG) promoter-triggered isopentenyltransferase (ipt), which encodes the key enzyme for cytokinin (CK) synthesis and mimics the action of exogenous supplied CK in delaying postharvest senescence of broccoli. Here, we used proteomics and transcriptomics to compare the mechanisms of ipt-transgenic and N(6)-benzylaminopurine (BA) CK treatment of broccoli during postharvest storage. The 2 treatments conferred common and distinct mechanisms. BA treatment decreased the quantity of proteins involved in energy and carbohydrate metabolism and amino acid metabolism, and ipt-transgenic treatment increased that of stress-related proteins and molecular chaperones and slightly affected levels of carbohydrate metabolism proteins. Both treatments regulated genes involved in CK signaling, sugar transport, energy and carbohydrate metabolism, amino acid metabolism and lipid metabolism, although ipt-transgenic treatment to a lesser extent. BA treatment induced genes encoding molecular chaperones, whereas ipt-transgenic treatment induced stress-related genes for cellular protection during storage. Both BA and ipt-transgenic treatments acted antagonistically on ethylene functions. We propose a long-term acclimation of metabolism and protection systems with ipt-transgenic treatment of broccoli and short-term modulation of metabolism and establishment of a protection system with both BA and ipt-transgenic treatments in delaying senescence of broccoli florets. Transgenic broccoli harboring senescence-associated-gene (SAG) promoter-triggered isopentenyltransferase (ipt), which encodes the key enzyme for cytokinin (CK) synthesis and N(6)-benzylaminopurine (BA) CK treated broccoli both showed retardation of postharvest senescence during storage. The mechanisms underlying the two treatments were compared. The combination of proteomic and transcriptomic evidences revealed that the 2 treatments conferred common

  19. Host pathogen relations: exploring animal models for fungal pathogens.

    Science.gov (United States)

    Harwood, Catherine G; Rao, Reeta P

    2014-06-30

    Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  20. Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Catherine G. Harwood

    2014-06-01

    Full Text Available Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.