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Leafy vegetables undergo abiotic and biotic stresses, and a series of processing steps that cause mechanical injury. Breaching the epidermis alters phyllosphere structural and nutrient conditions, resulting in successional shifts in leaf microbiota and entry of human pathogens. This study examined damage during processing of baby leaves (Swiss chard, spinach) and concomitant microbial successional events. Machine-harvesting, washing, and packaging caused major phyllosphere perturbations, with increasing levels of leaf damage. Older leaves showed most damage, but plant species was influential. Diversity estimates of bacterial and fungal communities revealed shifts in microbiota post-harvest, particularly after the washing step. Relative abundance of Pseudomonadaceae and Enterobacteriaceae increased from field to bag. Bacterial species specific to different harvesting and processing steps replaced core microbiota species. While processing is unavoidable, procedures that mitigate leaf damage can enhance shelf-life and food safety.
E. Mulaosmanovic; T.U.T. Lindblom; S.T. Windstam; M. Bengtsson; A.K. Rosberg; L. Mogren; B.W. Alsanius. Processing of leafy vegetables matters: Damage and microbial community structure from field to bag. Food Control 2021, 125, 107894 .
AMA StyleE. Mulaosmanovic, T.U.T. Lindblom, S.T. Windstam, M. Bengtsson, A.K. Rosberg, L. Mogren, B.W. Alsanius. Processing of leafy vegetables matters: Damage and microbial community structure from field to bag. Food Control. 2021; 125 ():107894.
Chicago/Turabian StyleE. Mulaosmanovic; T.U.T. Lindblom; S.T. Windstam; M. Bengtsson; A.K. Rosberg; L. Mogren; B.W. Alsanius. 2021. "Processing of leafy vegetables matters: Damage and microbial community structure from field to bag." Food Control 125, no. : 107894.
In Sub-Saharan Africa, being overweight in childhood is rapidly rising while stunting is still remaining at unacceptable levels. A key contributor to this double burden of malnutrition is dietary changes associated with nutrition transition. Although the importance of socio-economic drivers is known, there is limited knowledge about their stratification and relative importance to diet and to different forms of malnutrition. The aim of this study was to assess diet diversity and malnutrition in preschoolers and evaluate the relative importance of socioeconomic resources. Households with children under five (5467) were enrolled using a multi-stage sampling procedure. Standardized tools and procedures were used to collect data on diet, anthropometry and socio-economic factors. Multivariable analysis with cluster adjustment was performed. The prevalence of stunting was 19.6% (18.5–20.6), wasting 3.2% (2.8–3.7), and overweight/obesity 11.4% (10.6–12.2). Stunting, overweight, wasting and limited diet diversity was present in all social strata. Low maternal education was associated with an increased risk of stunting (Adjusted odds ratio (AOR): 1.8; 1.4–2.2), limited diet diversity (AOR: 0.33; 0.26–0.42) and reduced odds of being overweight (AOR: 0.61; 0.44–0.84). Preschoolers in Addis Ababa have limited quality diets and suffer from both under- and over-nutrition. Maternal education was an important explanatory factor for stunting and being overweight. Interventions that promote diet quality for the undernourished whilst also addressing the burgeoning problem of being overweight are needed.
Hanna Y. Berhane; Magnus Jirström; Semira Abdelmenan; Yemane Berhane; Beatrix Alsanius; Jill Trenholm; Eva-Charlotte Ekström. Social Stratification, Diet Diversity and Malnutrition among Preschoolers: A Survey of Addis Ababa, Ethiopia. Nutrients 2020, 12, 712 .
AMA StyleHanna Y. Berhane, Magnus Jirström, Semira Abdelmenan, Yemane Berhane, Beatrix Alsanius, Jill Trenholm, Eva-Charlotte Ekström. Social Stratification, Diet Diversity and Malnutrition among Preschoolers: A Survey of Addis Ababa, Ethiopia. Nutrients. 2020; 12 (3):712.
Chicago/Turabian StyleHanna Y. Berhane; Magnus Jirström; Semira Abdelmenan; Yemane Berhane; Beatrix Alsanius; Jill Trenholm; Eva-Charlotte Ekström. 2020. "Social Stratification, Diet Diversity and Malnutrition among Preschoolers: A Survey of Addis Ababa, Ethiopia." Nutrients 12, no. 3: 712.
Horticultural greenhouse production in circumpolar regions (>60° N latitude), but also at lower latitudes, is dependent on artificial assimilation lighting to improve plant performance and the profitability of ornamental crops, and to secure production of greenhouse vegetables and berries all year round. In order to reduce energy consumption and energy costs, alternative technologies for lighting have been introduced, including light-emitting diodes (LED). This technology is also well-established within urban farming, especially plant factories. Different light technologies influence biotic and abiotic conditions in the plant environment. This review focuses on the impact of light quality on plant–microbe interactions, especially non-phototrophic organisms. Bacterial and fungal pathogens, biocontrol agents, and the phyllobiome are considered. Relevant molecular mechanisms regulating light-quality-related processes in bacteria are described and knowledge gaps are discussed with reference to ecological theories.
Beatrix Alsanius; Maria Karlsson; Anna Rosberg; Martine Dorais; Most Naznin; Sammar Khalil; Karl-Johan Bergstrand. Light and Microbial Lifestyle: The Impact of Light Quality on Plant–Microbe Interactions in Horticultural Production Systems—A Review. Horticulturae 2019, 5, 41 .
AMA StyleBeatrix Alsanius, Maria Karlsson, Anna Rosberg, Martine Dorais, Most Naznin, Sammar Khalil, Karl-Johan Bergstrand. Light and Microbial Lifestyle: The Impact of Light Quality on Plant–Microbe Interactions in Horticultural Production Systems—A Review. Horticulturae. 2019; 5 (2):41.
Chicago/Turabian StyleBeatrix Alsanius; Maria Karlsson; Anna Rosberg; Martine Dorais; Most Naznin; Sammar Khalil; Karl-Johan Bergstrand. 2019. "Light and Microbial Lifestyle: The Impact of Light Quality on Plant–Microbe Interactions in Horticultural Production Systems—A Review." Horticulturae 5, no. 2: 41.
Despite numerous outbreaks of foodborne illnesses associated with sprouts, consumption of raw sprouted seeds is still linked with a healthy lifestyle in Scandinavia. Different types of sprouting modules for home sprout production are available on the market, and sold without information about risks associated with sprouting. During sprouting, conditions are ideal for seed emergence, but also for bacterial proliferation. Moreover, since seeds used for sprouting are non-sterile, human pathogens may propagate within sprouting modules. This study assessed vertical dispersal of Escherichia coli strain O157:H7 in two types of three-layered sprouting modules intended for home sprouting. Organic fenugreek seeds were artificially inoculated and transferred to either the top or bottom layer of sprouting modules. As commensal bacterial biota can affect survival of an artificially introduced strain, but can also contain pathogens, culturable bacterial species on fenugreek seeds were evaluated. A Beta-Poisson model was used to assess the risk of consumer exposure to the artificially introduced strain when added to seeds in the top or bottom layer. We found that the inoculated strain dispersed vertically up and down between the layers and that the risk of bacterial dispersal was high in either direction, posing a high risk of consumer exposure.
Emina Mulaosmanovic; Sebastian Farkas; Ivar Vågsholm; Julia Darlison; Maria Sousa; Lars Mogren; Samareh Gharaie; Beatrix W. Alsanius; Julia Lindén. Safety risks associated with dispersal of E. coli O157:H7 in home sprouting modules. LWT 2018, 101, 783 -788.
AMA StyleEmina Mulaosmanovic, Sebastian Farkas, Ivar Vågsholm, Julia Darlison, Maria Sousa, Lars Mogren, Samareh Gharaie, Beatrix W. Alsanius, Julia Lindén. Safety risks associated with dispersal of E. coli O157:H7 in home sprouting modules. LWT. 2018; 101 ():783-788.
Chicago/Turabian StyleEmina Mulaosmanovic; Sebastian Farkas; Ivar Vågsholm; Julia Darlison; Maria Sousa; Lars Mogren; Samareh Gharaie; Beatrix W. Alsanius; Julia Lindén. 2018. "Safety risks associated with dispersal of E. coli O157:H7 in home sprouting modules." LWT 101, no. : 783-788.
Mothers carry the prime responsibility for childcare and feeding in low-income countries. Understanding their experiences in providing food for their children is paramount to informing efforts to improve the nutritional status of children. Such information is lacking in Sub-Saharan Africa. To understand what influences urban mothers’ food acquisition and their motivations for selecting food for their children, 36 in-depth interviews were carried out with mothers having children under five years of age. Interviews were conducted in the local language, audio-recorded, transcribed, and translated into English. Data were analyzed using thematic analysis which led to the identification of four major themes: mothers give-in to a child-driven diet; quick-fix versus the privilege of planning; keen awareness on food safety, nutrition, and diet diversity; and social, familial, and cultural influences. The findings indicate that child feeding practices are influenced by interlinked social and environmental factors. Hence, nutrition education campaigns should focus on targeting not only families but also their children. Attention should also be given to food safety regulations, as well as to the much-needed support of mothers who are struggling to ensure their children’s survival in low-income countries.
Hanna Y. Berhane; Eva-Charlotte Ekström; Magnus Jirström; Yemane Berhane; Christopher Turner; Beatrix W. Alsanius; Jill Trenholm. What Influences Urban Mothers’ Decisions on What to Feed Their Children Aged Under Five—The Case of Addis Ababa, Ethiopia. Nutrients 2018, 10, 1142 .
AMA StyleHanna Y. Berhane, Eva-Charlotte Ekström, Magnus Jirström, Yemane Berhane, Christopher Turner, Beatrix W. Alsanius, Jill Trenholm. What Influences Urban Mothers’ Decisions on What to Feed Their Children Aged Under Five—The Case of Addis Ababa, Ethiopia. Nutrients. 2018; 10 (9):1142.
Chicago/Turabian StyleHanna Y. Berhane; Eva-Charlotte Ekström; Magnus Jirström; Yemane Berhane; Christopher Turner; Beatrix W. Alsanius; Jill Trenholm. 2018. "What Influences Urban Mothers’ Decisions on What to Feed Their Children Aged Under Five—The Case of Addis Ababa, Ethiopia." Nutrients 10, no. 9: 1142.
Despite the overruling impact of light in the phyllosphere, little is known regarding the influence of light spectra on non-phototrophic bacteria colonizing the leaf surface. We developed an in vitro method to study phenotypic profile responses of bacterial pure cultures to different bands of the visible light spectrum using monochromatic (blue: 460 nm; red: 660 nm) and polychromatic (white: 350–990 nm) LEDs, by modification and optimization of a protocol for the Phenotype MicroArray™ technique (Biolog Inc., CA, USA). The new protocol revealed high reproducibility of substrate utilization under all conditions tested. Challenging the non-phototrophic bacterium Pseudomonas sp. DR 5–09 with white, blue, and red light demonstrated that all light treatments affected the respiratory profile differently, with blue LED having the most decisive impact on substrate utilization by impairing respiration of 140 substrates. The respiratory activity was decreased on 23 and 42 substrates under red and white LEDs, respectively, while utilization of one, 16, and 20 substrates increased in the presence of red, blue, and white LEDs, respectively. Interestingly, on four substrates contrasting utilization patterns were found when the bacterium was exposed to different light spectra. Although non-phototrophic bacteria do not rely directly on light as an energy source, Pseudomonas sp. DR 5–09 changed its respiratory activity on various substrates differently when exposed to different lights. Thus, ability to sense and distinguish between different wavelengths even within the visible light spectrum must exist, and leads to differential regulation of substrate usage. With these results, we hypothesize that different light spectra might be a hitherto neglected key stimulus for changes in microbial lifestyle and habits of substrate usage by non-phototrophic phyllospheric microbiota, and thus might essentially stratify leaf microbiota composition and diversity.
Samareh Gharaie; Lea A. I. Vaas; Anna Karin Rosberg; Sofia T. Windstam; Maria E. Karlsson; Karl-Johan Bergstrand; Sammar Khalil; Walter Wohanka; Beatrix W. Alsanius. Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09. PLOS ONE 2017, 12, e0189862 .
AMA StyleSamareh Gharaie, Lea A. I. Vaas, Anna Karin Rosberg, Sofia T. Windstam, Maria E. Karlsson, Karl-Johan Bergstrand, Sammar Khalil, Walter Wohanka, Beatrix W. Alsanius. Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09. PLOS ONE. 2017; 12 (12):e0189862.
Chicago/Turabian StyleSamareh Gharaie; Lea A. I. Vaas; Anna Karin Rosberg; Sofia T. Windstam; Maria E. Karlsson; Karl-Johan Bergstrand; Sammar Khalil; Walter Wohanka; Beatrix W. Alsanius. 2017. "Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09." PLOS ONE 12, no. 12: e0189862.
Within sustainable production, produce quality and safety are essential features. However, methods, requirements, conditions and even legislation for produce quality and safety in production in rural areas cannot always be directly transferred to production in urban areas and on rooftops. This chapter describes features of produce quality, produce safety and safety hazards in urban rooftop farming employing various technological solutions and serving various purposes in different climate zones. Sustainability is discussed in terms of product quality and safety, and requirements to resolve the principal issues are presented.
Beatrix W. Alsanius; Andrea Kosiba Held; Martine Dorais; Cecilia Onyango; Lars Mogren. Produce Quality and Safety. Urban Agriculture 2017, 195 -216.
AMA StyleBeatrix W. Alsanius, Andrea Kosiba Held, Martine Dorais, Cecilia Onyango, Lars Mogren. Produce Quality and Safety. Urban Agriculture. 2017; ():195-216.
Chicago/Turabian StyleBeatrix W. Alsanius; Andrea Kosiba Held; Martine Dorais; Cecilia Onyango; Lars Mogren. 2017. "Produce Quality and Safety." Urban Agriculture , no. : 195-216.
Multitrophic water-based production systems, such as aquaponics, are a means to supply animal protein, fish lipids and high-quality horticultural produce rich in fibre, minerals and bioactive compounds in urban areas. In this chapter, we describe the specific demands of fish and crop production and technological solutions. However, for long-term economic viability, financial investment in such systems must be met by sustainable economic output from the systems. For methods such as rooftop aquaponics, further system development and capacity building are therefore essential preconditions for wider establishment in urban areas.
Beatrix W. Alsanius; Sammar Khalil; Rolf Morgenstern. Rooftop Aquaponics. Urban Agriculture 2017, 103 -112.
AMA StyleBeatrix W. Alsanius, Sammar Khalil, Rolf Morgenstern. Rooftop Aquaponics. Urban Agriculture. 2017; ():103-112.
Chicago/Turabian StyleBeatrix W. Alsanius; Sammar Khalil; Rolf Morgenstern. 2017. "Rooftop Aquaponics." Urban Agriculture , no. : 103-112.
Beatrix W. Alsanius; Karl-Johan Bergstrand; Rahel Hartmann; Samareh Gharaie; Walter Wohanka; Martine Dorais; Anna Karin Rosberg. Ornamental flowers in new light: Artificial lighting shapes the microbial phyllosphere community structure of greenhouse grown sunflowers (Helianthus annuus L.). Scientia Horticulturae 2017, 216, 234 -247.
AMA StyleBeatrix W. Alsanius, Karl-Johan Bergstrand, Rahel Hartmann, Samareh Gharaie, Walter Wohanka, Martine Dorais, Anna Karin Rosberg. Ornamental flowers in new light: Artificial lighting shapes the microbial phyllosphere community structure of greenhouse grown sunflowers (Helianthus annuus L.). Scientia Horticulturae. 2017; 216 ():234-247.
Chicago/Turabian StyleBeatrix W. Alsanius; Karl-Johan Bergstrand; Rahel Hartmann; Samareh Gharaie; Walter Wohanka; Martine Dorais; Anna Karin Rosberg. 2017. "Ornamental flowers in new light: Artificial lighting shapes the microbial phyllosphere community structure of greenhouse grown sunflowers (Helianthus annuus L.)." Scientia Horticulturae 216, no. : 234-247.
Martine Dorais; Beatrix Waechter Alsanius. Recent advances in organic horticulture technology and management. Scientia Horticulturae 2016, 208, 1 -2.
AMA StyleMartine Dorais, Beatrix Waechter Alsanius. Recent advances in organic horticulture technology and management. Scientia Horticulturae. 2016; 208 ():1-2.
Chicago/Turabian StyleMartine Dorais; Beatrix Waechter Alsanius. 2016. "Recent advances in organic horticulture technology and management." Scientia Horticulturae 208, no. : 1-2.
Highlights•Premature browning (PMB) occurred in hamburgers packaged in high oxygen atmosphere.•PMB led to shorter heating times and higher survival at all consumer preference colour scores.•Doneness judgement based on both meat colour and texture improves safety.•Under present conditions PMB increased relative risk for illness up to 300 times compared with controls.•Variable microbial reduction at recommended core temperatures constituted was a potential risk. AbstractThis study investigated the effect of premature browning (PMB) on the survival of Escherichia coli O157:H7 in beef hamburgers after cooking with respect to interior colour of the hamburger and recommendations to cook hamburgers to a core temperature of 71 °C. Assessment of doneness by visual inspection or measurement of internal temperature was compared in terms of survival and the increased relative risk of illness due to PMB was estimated. At the last consume-by-day, hamburgers made from minced meat packaged in 80/20 O2/CO2 (MAP hamburger) and from meat minced at retail packaged in atmospheric condition (control hamburger) were inoculated with a gfp-tagged strain of E. coli O157:H7 (E. coli O157:H7gfp+). Hamburgers were cooked for different times during assessment of the core temperature every 30 s and cut in halves after cooking. Doneness was evaluated based on visual judgement of the internal colour using a score chart (C-score) from ‘uncooked’ (score 1) to ‘tan with no evidence of pink’ (score 5). An alternative five point score chart (TCC-score) including texture of the meat, clarity of meat juice and internal colour was also developed. Enumeration of viable E. coli O157:H7gfp+ in cooked hamburgers was based on fluorescent colonies recovered from plates. Results showed that MAP hamburgers developed PMB when compared with controls (P = 0.0003) and that the shortest cooking time for the highest C-score was 6 and 11 min for MAP and control hamburgers, respectively. The mean temperature in the MAP hamburger was then 60.3 °C. The TCC-score reduced the difference between MAP and control hamburgers. It was also shown that the survival of E. coli O157:H7gfp+ was highest in MAP hamburgers. The predicted absolute risks for illness were highest for MAP hamburgers for all C-scores and the relative risk associated with PMB increased with doneness. For a C-score of 4 (slightly pink) the predicted relative risk for illness was 300 times higher for MAP hamburger than for controls. A variable pathogen reduction was observed when cooking hamburgers to temperatures of 70–76 °C (the 5th and 95th percentile range was around 3.3 log CFU). The lower reductions, at the 5th percentile, may, depending on initial contamination levels, not be enough to ensure sufficient and safe inactivation of E. coli O157:H7. Efforts to inform consumers about PMB in minced meat packaged in high oxygen packages (≥ 60% O2) are needed with the aim to make consumers use thermometers correctly or at least not determine doneness based only on meat colour.
Sofia Boqvist; Lise-Lotte Fernström; Beatrix W. Alsanius; Roland Lindqvist. Escherichia coli O157:H7 reduction in hamburgers with regard to premature browning of minced beef, colour score and method for determining doneness. International Journal of Food Microbiology 2015, 215, 109 -116.
AMA StyleSofia Boqvist, Lise-Lotte Fernström, Beatrix W. Alsanius, Roland Lindqvist. Escherichia coli O157:H7 reduction in hamburgers with regard to premature browning of minced beef, colour score and method for determining doneness. International Journal of Food Microbiology. 2015; 215 ():109-116.
Chicago/Turabian StyleSofia Boqvist; Lise-Lotte Fernström; Beatrix W. Alsanius; Roland Lindqvist. 2015. "Escherichia coli O157:H7 reduction in hamburgers with regard to premature browning of minced beef, colour score and method for determining doneness." International Journal of Food Microbiology 215, no. : 109-116.
Currently, there is little knowledge of the establishment of repeatedly applied biological control agents (BCAs) in the phyllosphere of plants and, in particular, their interactions with the resident microbiome. Under field conditions, the BCA Aureobasidium pullulans was applied as a model organism to organically grown strawberries during two subsequent years (2011, 2012), either as single strain treatment or with the co-application of the entomopathogenic fungus Beauveria bassiana. Fungal and bacterial communities of strawberry leaves were investigated by means of plate counts and 454 pyrosequencing. The establishment of the introduced A. pullulans strains considerably differed between the two years, presumably due to distinct environmental conditions. Short-term and long-term effects of BCA applications on the composition and diversity of fungal communities could be observed as a result of successful establishment of A. pullulans, in 2011, showing, for instance, reduced diversity of fungal communities by competitive displacement shortly after BCA introduction. Due to considerable dynamics in untreated resident microbial communities in the phyllosphere in general, however, we suggest that even the effects caused by the applied BCA preparations in 2011 are negligible under practical conditions.
Justine Sylla; Beatrix W. Alsanius; Erika Krüger; Annette Reineke; Monika Bischoff-Schaefer; Walter Wohanka. Introduction of Aureobasidium pullulans to the Phyllosphere of Organically Grown Strawberries with Focus on Its Establishment and Interactions with the Resident Microbiome. Agronomy 2013, 3, 704 -731.
AMA StyleJustine Sylla, Beatrix W. Alsanius, Erika Krüger, Annette Reineke, Monika Bischoff-Schaefer, Walter Wohanka. Introduction of Aureobasidium pullulans to the Phyllosphere of Organically Grown Strawberries with Focus on Its Establishment and Interactions with the Resident Microbiome. Agronomy. 2013; 3 (4):704-731.
Chicago/Turabian StyleJustine Sylla; Beatrix W. Alsanius; Erika Krüger; Annette Reineke; Monika Bischoff-Schaefer; Walter Wohanka. 2013. "Introduction of Aureobasidium pullulans to the Phyllosphere of Organically Grown Strawberries with Focus on Its Establishment and Interactions with the Resident Microbiome." Agronomy 3, no. 4: 704-731.
The increasing use of biological control agents (BCAs) against Botrytis cinerea in strawberry raises the question of whether there are any undesirable impacts of foliar applications of BCAs on nontarget microorganisms in the phyllosphere. Therefore, our objective was to investigate this issue within a field study. Strawberry plants were repeatedly sprayed with three BCAs—namely, RhizoVital 42 fl. (Bacillus amyloliquefaciens FZB42), Trianum-P (Trichoderma harzianum T22), and Naturalis (Beauveria bassiana ATCC 74040)—to suppress Botrytis cinerea infections. Microbial communities of differentially treated leaves were analyzed using plate counts and pyrosequencing and compared with the microbial community of nontreated leaves. Plate count results indicate that the applied Bacillus and Trichoderma spp. survived in the strawberry phyllosphere throughout the strawberry season. However, no significant impacts on the leaf microbiota could be detected by this culture-dependent technique. Pyrosequencing of internal transcribed spacer ribosomal RNA and 16S RNA sequences revealed a change in fungal composition and diversity at class level after the introduction of T. harzianum T22 to the phyllosphere, whereas the bacterial composition and diversity was not affected by either this Trichoderma preparation or the other two BCAs. Our results suggest that pyrosequencing represents a useful method for studying microbial interactions in the phyllosphere.
Justine Sylla; Beatrix W. Alsanius; Erika Krüger; Annette Reineke; Stephan Strohmeier; Walter Wohanka. Leaf Microbiota of Strawberries as Affected by Biological Control Agents. Phytopathology® 2013, 103, 1001 -1011.
AMA StyleJustine Sylla, Beatrix W. Alsanius, Erika Krüger, Annette Reineke, Stephan Strohmeier, Walter Wohanka. Leaf Microbiota of Strawberries as Affected by Biological Control Agents. Phytopathology®. 2013; 103 (10):1001-1011.
Chicago/Turabian StyleJustine Sylla; Beatrix W. Alsanius; Erika Krüger; Annette Reineke; Stephan Strohmeier; Walter Wohanka. 2013. "Leaf Microbiota of Strawberries as Affected by Biological Control Agents." Phytopathology® 103, no. 10: 1001-1011.
Beatrix W. Alsanius; Karl-Johan Bergstrand; Stephen Burleigh; Nicolas Gruyer; Anna Karin Rosberg. Persistence of fenhexamid in the nutrient solution of a closed cropping system. Agricultural Water Management 2013, 127, 25 -30.
AMA StyleBeatrix W. Alsanius, Karl-Johan Bergstrand, Stephen Burleigh, Nicolas Gruyer, Anna Karin Rosberg. Persistence of fenhexamid in the nutrient solution of a closed cropping system. Agricultural Water Management. 2013; 127 ():25-30.
Chicago/Turabian StyleBeatrix W. Alsanius; Karl-Johan Bergstrand; Stephen Burleigh; Nicolas Gruyer; Anna Karin Rosberg. 2013. "Persistence of fenhexamid in the nutrient solution of a closed cropping system." Agricultural Water Management 127, no. : 25-30.
Biological control of plant pathogens on strawberries may be improved by the simultaneous application of different biological control agents (BCAs). Therefore, the compatibility of various BCAs which had previously shown to be effective against powdery mildew (Podosphaera aphanis (Wallr.) U. Braun & S. Takam) under laboratory conditions was examined in vitro. Inhibitory effects between fungal and bacterial BCAs were demonstrated in dual culture tests on two solid nutrient media. Leaf disc assays with single and multiple strain treatments demonstrated either unaffected or significantly improved control of P. aphanis for many multiple strain treatments, even if antagonistic interactions previously occurred in dual culture tests. Highest inhibition of powdery mildew conidiation (80.7% reduction) was achieved with multiple strain treatments with Bacillus subtilis FZB24 and Metarhizium anisopliae (p<0.001). In this combination, conidiation was 3.7 times lower than in single treatments with B. subtilis indicating synergistic interactions between these BCAs. Combinations of Trichoderma harzianum T58 and B. subtilis FZB24 showed antagonistic interactions in dual culture tests as well as in leaf disc assays. In this combination, powdery mildew conidiation on leaf discs was four times higher compared to single treatments with T. harzianum T58
Justine Sylla; Beatrix W. Alsanius; Erika Krüger; Dorit Becker; Walter Wohanka. In vitro compatibility of microbial agents for simultaneous application to control strawberry powdery mildew (Podosphaera aphanis). Crop Protection 2013, 51, 40 -47.
AMA StyleJustine Sylla, Beatrix W. Alsanius, Erika Krüger, Dorit Becker, Walter Wohanka. In vitro compatibility of microbial agents for simultaneous application to control strawberry powdery mildew (Podosphaera aphanis). Crop Protection. 2013; 51 ():40-47.
Chicago/Turabian StyleJustine Sylla; Beatrix W. Alsanius; Erika Krüger; Dorit Becker; Walter Wohanka. 2013. "In vitro compatibility of microbial agents for simultaneous application to control strawberry powdery mildew (Podosphaera aphanis)." Crop Protection 51, no. : 40-47.
The goal of this study was to evaluate the use of passive bioreactors to reduce water-borne plant pathogens (Pythium ultimum and Fusarium oxysporum) and nutrient load (NO−3 and SO2−4) in greenhouse effluent. Sterilized and unsterilized passive bioreactors filled with a reactive mixture of organic carbon material were used in three replicates. After a startup period of 2 (sterilized) or 5 (unsterilized) weeks, the bioreactor units received for 14 weeks a reconstituted commercial greenhouse effluent composed of 500 mg L−1 SO2−4 and 300 mg L−1 NO−3 and were inoculated three times with P. ultimum and F. oxysporum (106 CFU mL−1). Efficacy in removing water-borne plant pathogens and nitrate reached 99.9% for both the sterilized and unsterilized bioreactors. However, efficacy in reducing the SO2−4 load sharply decreased from 89% to 29% after 2 weeks of NO−3-supply treatment for the unsterilized bioreactors. Although SO2−4 removal efficacy for the sterilized bioreactors did not recover after 4 weeks of NO−3-supply treatment, the unsterilized bioreactor nearly reached a similar level of SO2−4 removal after 4 weeks of NO−3-supply treatment compared with affluent loaded only with SO2−4, where no competition for the carbohydrate source occurred between the denitrification process and sulfate-reducing bacteria activity. Performance differences between the sterilized and unsterilized bioreactors clearly show the predominant importance of sulfate-reducing bacteria. Consequently, when sulfate-reducing bacteria reach their optimal activity, passive bioreactors may constitute a cheap, low-maintenance method of treating greenhouse effluent to recycle wastewater and eliminate nutrient runoff, which has important environmental impacts.
Nicolas Gruyer; Martine Dorais; Beatrix W. Alsanius; Gérald J. Zagury. Use of a passive bioreactor to reduce water-borne plant pathogens, nitrate, and sulfate in greenhouse effluent. Journal of Environmental Science and Health, Part A 2013, 48, 1740 -1747.
AMA StyleNicolas Gruyer, Martine Dorais, Beatrix W. Alsanius, Gérald J. Zagury. Use of a passive bioreactor to reduce water-borne plant pathogens, nitrate, and sulfate in greenhouse effluent. Journal of Environmental Science and Health, Part A. 2013; 48 (13):1740-1747.
Chicago/Turabian StyleNicolas Gruyer; Martine Dorais; Beatrix W. Alsanius; Gérald J. Zagury. 2013. "Use of a passive bioreactor to reduce water-borne plant pathogens, nitrate, and sulfate in greenhouse effluent." Journal of Environmental Science and Health, Part A 48, no. 13: 1740-1747.
This study evaluated the effectiveness of C-enriched subsurface-flow constructed wetlands in reducing high concentrations of nitrate (NO3−) and sulfate (SO42−) in greenhouse wastewaters. Constructed wetlands were filled with pozzolana, planted with common cattail (Typha latifolia), and supplemented as follows: (i) constructed wetland with sucrose (CW+S), wetland units with 2 g L−1 of sucrose solution from week 1 to 28; (ii) constructed wetland with compost (CW+C), wetland units supplemented with a reactive mixture of compost and sawdust; (iii) constructed wetland with compost and no sucrose (CW+CNS) from week 1 to 18, and constructed wetland with compost and sucrose (CW+CS) at 2 g L−1 from week 19 to 28; and (iv) constructed wetland (CW). During 28 wk, the wetlands received a typical reconstituted greenhouse wastewater containing 500 mg L−1 SO42− and 300 mg L−1 NO3−. In CW+S, CW+C, and CW+CS, appropriate C:N ratio (7:3.4) and redox potential (−53 to 39 mV) for denitrification resulted in 95 to 99% NO3− removal. Carbon source was not a limiting factor for denitrification in C-enriched constructed wetlands. In CW+S and CW+CS, the dissolved organic carbon (DOC)/SO42− ratios of 0.36 and 0.28 resulted in high sulfate-reducing bacteria (SRB) counts and high SO42− removal (98%), whereas low activities were observed at DOC/SO42− ratios of 0.02 (CW) to 0.11 (CW+C, CW+CNS). On week 19, when organic C content was increased by sucrose addition in CW+CS, SRB counts increased from 2.80 to 5.11 log[CFU+1] mL−1, resulting in a level similar to the one measured in CW+S (4.69 log[CFU+1] mL−1). Consequently, high sulfate reduction occurred after denitrification, suggesting that low DOC (38–54 mg L−1) was the limiting factor. In CW, DOC concentration (9–10 mg L−1) was too low to sustain efficient denitrification and, therefore, sulfate reduction. Furthermore, the high concentration of dissolved sulfides observed in CW+S and CW+CS treated waters were eliminated by adding FeCl3. Copyright © 2013. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
Nicolas Gruyer; Martine Dorais; Beatrix W. Alsanius; Gérald J. Zagury. Simultaneous Removal of Nitrate and Sulfate from Greenhouse Wastewater by Constructed Wetlands. Journal of Environmental Quality 2013, 42, 1256 -1266.
AMA StyleNicolas Gruyer, Martine Dorais, Beatrix W. Alsanius, Gérald J. Zagury. Simultaneous Removal of Nitrate and Sulfate from Greenhouse Wastewater by Constructed Wetlands. Journal of Environmental Quality. 2013; 42 (4):1256-1266.
Chicago/Turabian StyleNicolas Gruyer; Martine Dorais; Beatrix W. Alsanius; Gérald J. Zagury. 2013. "Simultaneous Removal of Nitrate and Sulfate from Greenhouse Wastewater by Constructed Wetlands." Journal of Environmental Quality 42, no. 4: 1256-1266.
The objectives of this study were to evaluate the risks and benefits of using artificial wetland-treated waters to irrigate tomato plants (Lycopersicom esculentum) and the potential for suppression of Pythium ultimum. The experiment was conducted in a greenhouse using tap water (control) and treated waters coming from three types of horizontal subsurface flow artificial wetlands filled with pozzolana and implanted with common cattail (Typha latifolia). Wetland units contained either a simple [artificial wetland with sucrose (AWS)] or complex [artificial wetland with compost (AWC)] carbon source or no [artificial wetland with no carbon (AW)] additional carbon source. A complete randomized split-block design comparing root sensitivity to root rot (inoculated and uninoculated plants) in main plots and four nutrient solutions [1) control, 2) treated water from AWS, 3) treated water from AWC, and 4) treated water from AW] in subplots was used in six replications. Tomato plants were inoculated with P. ultimum twice during the experimental period. The use of treated waters reduced the in vivo root Pythium population by 84% and 100% when the treated waters were from AWS and AWC, respectively. In vitro trials showed that sterilization or membrane filtration (0.2 μm) of treated waters significantly reduced the potential for suppression of P. ultimum, suggesting that microbial activity played an important role. On the other hand, all AW-treated waters had a negative effect on root development of uninoculated young tomato plants. Root dry weights of plants irrigated with treated waters was 56% lower than in control plants, while their shoot:root ratio was two times higher for plants irrigated with treated waters. The inoculated and AWC-treated water treatments also reduced the Fv:Fm ratio of dark-adapted leaves, representing the maximum quantum efficiency of photosystem II. Organic compounds present in treated waters, expressed as total and dissolved organic compounds, may have affected tomato root development.
Nicolas Gruyer; Martine Dorais; Gérald J. Zagury; Beatrix W. Alsanius. Effects of Using Water Treated by Artificial Wetlands on Root Rot Suppression and Tomato Growth. HortTechnology 2011, 21, 759 -766.
AMA StyleNicolas Gruyer, Martine Dorais, Gérald J. Zagury, Beatrix W. Alsanius. Effects of Using Water Treated by Artificial Wetlands on Root Rot Suppression and Tomato Growth. HortTechnology. 2011; 21 (6):759-766.
Chicago/Turabian StyleNicolas Gruyer; Martine Dorais; Gérald J. Zagury; Beatrix W. Alsanius. 2011. "Effects of Using Water Treated by Artificial Wetlands on Root Rot Suppression and Tomato Growth." HortTechnology 21, no. 6: 759-766.
Three commercial biocontrol agents [Trichoderma polysporum plus T. harzianum (Binab T), Gliocladium cantenulatum (Gliomix), and Streptomyces griseoviridis (Mycostop)] were evaluated for their ability to reduce root diseases caused by Pythium aphanidermatum, Phytophthora cryptogea, or Fusarium oxysporum f. sp. radicis-lycopersici in hydroponically-grown tomatoes. Studies were performed using two types of growing medium, peat or pumice, under controlled conditions in a closed irrigation system. The level of disease control varied depending on the biocontrol agent, growing medium, and pathogen. In pumice, amendment with Binab T, Gliomix, or Mycostop reduced the levels and disease incidence of all three pathogens. However, Mycostop had no significant effect on the level of any of the three pathogens in peat, although Binab T and Gliomix both achieved successful biocontrol. In both growth media, biocontrol of F. oxysporum f. sp. radicis-lycopersici was poor compared with that of P. aphanidermatum or P. cryptogea. Overall, tomato plant growth increased after the introduction of any of the biocontrol agents, in the presence of any of the three pathogens, compared with the untreated controls.
Sammar Khalil; Malin Hultberg; Beatrix W. Alsanius. Effects of growing medium on the interactions between biocontrol agents and tomato root pathogens in a closed hydroponic system. The Journal of Horticultural Science and Biotechnology 2009, 84, 489 -494.
AMA StyleSammar Khalil, Malin Hultberg, Beatrix W. Alsanius. Effects of growing medium on the interactions between biocontrol agents and tomato root pathogens in a closed hydroponic system. The Journal of Horticultural Science and Biotechnology. 2009; 84 (5):489-494.
Chicago/Turabian StyleSammar Khalil; Malin Hultberg; Beatrix W. Alsanius. 2009. "Effects of growing medium on the interactions between biocontrol agents and tomato root pathogens in a closed hydroponic system." The Journal of Horticultural Science and Biotechnology 84, no. 5: 489-494.
Thomas Brand; Walter Wohanka; Beatrix W Alsanius. Enzyme activity assays for nutrient solutions from closed irrigation systems. Scientia Horticulturae 2002, 92, 329 -338.
AMA StyleThomas Brand, Walter Wohanka, Beatrix W Alsanius. Enzyme activity assays for nutrient solutions from closed irrigation systems. Scientia Horticulturae. 2002; 92 (3):329-338.
Chicago/Turabian StyleThomas Brand; Walter Wohanka; Beatrix W Alsanius. 2002. "Enzyme activity assays for nutrient solutions from closed irrigation systems." Scientia Horticulturae 92, no. 3: 329-338.