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Athilingam T, Nelanuthala AVS, Breen C, Karedla N, Fritzsche M, Wohland T, Saunders TE. Long-range formation of the Bicoid gradient requires multiple dynamic modes that spatially vary across the embryo. Development 2024; 151:dev202128. [PMID: 38345326 PMCID: PMC10911119 DOI: 10.1242/dev.202128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 01/03/2024] [Indexed: 02/15/2024]
Abstract
Morphogen gradients provide essential positional information to gene networks through their spatially heterogeneous distribution, yet how they form is still hotly contested, with multiple models proposed for different systems. Here, we focus on the transcription factor Bicoid (Bcd), a morphogen that forms an exponential gradient across the anterior-posterior (AP) axis of the early Drosophila embryo. Using fluorescence correlation spectroscopy we find there are spatial differences in Bcd diffusivity along the AP axis, with Bcd diffusing more rapidly in the posterior. We establish that such spatially varying differences in Bcd dynamics are sufficient to explain how Bcd can have a steep exponential gradient in the anterior half of the embryo and yet still have an observable fraction of Bcd near the posterior pole. In the nucleus, we demonstrate that Bcd dynamics are impacted by binding to DNA. Addition of the Bcd homeodomain to eGFP::NLS qualitatively replicates the Bcd concentration profile, suggesting this domain regulates Bcd dynamics. Our results reveal how a long-range gradient can form while retaining a steep profile through much of its range.
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Affiliation(s)
- Thamarailingam Athilingam
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
- Mechanobiology Institute, National University of Singapore, Singapore117411
| | - Ashwin V. S. Nelanuthala
- Department of Biological Sciences and Centre for Bioimaging Sciences, National University of Singapore, Singapore117558
| | | | - Narain Karedla
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, OX3 7LF, UK
| | - Marco Fritzsche
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, OX3 7LF, UK
| | - Thorsten Wohland
- Department of Biological Sciences and Centre for Bioimaging Sciences, National University of Singapore, Singapore117558
- Department of Chemistry, National University of Singapore, Singapore117558
| | - Timothy E. Saunders
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
- Mechanobiology Institute, National University of Singapore, Singapore117411
- Department of Biological Sciences and Centre for Bioimaging Sciences, National University of Singapore, Singapore117558
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Hernández AI, Specht CD. Putative adaptive loci show parallel clinal variation in a California-endemic wildflower. Mol Ecol 2023. [PMID: 37246603 DOI: 10.1111/mec.17029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/27/2023] [Accepted: 05/12/2023] [Indexed: 05/30/2023]
Abstract
As the global climate crisis continues, predictions concerning how wild populations will respond to changing climate conditions are informed by an understanding of how populations have responded and/or adapted to climate variables in the past. Changes in the local biotic and abiotic environment can drive differences in phenology, physiology, morphology and demography between populations leading to local adaptation, yet the molecular basis of adaptive evolution in wild non-model organisms is poorly understood. We leverage comparisons between two lineages of Calochortus venustus occurring along parallel transects that allow us to identify loci under selection and measure clinal variation in allele frequencies as evidence of population-specific responses to selection along climatic gradients. We identify targets of selection by distinguishing loci that are outliers to population structure and by using genotype-environment associations across transects to detect loci under selection from each of nine climatic variables. Despite gene flow between individuals of different floral phenotypes and between populations, we find evidence of ecological specialization at the molecular level, including genes associated with key plant functions linked to plant adaptation to California's Mediterranean climate. Single-nucleotide polymorphisms (SNPs) present in both transects show similar trends in allelic similarity across latitudes indicating parallel adaptation to northern climates. Comparisons between eastern and western populations across latitudes indicate divergent genetic evolution between transects, suggesting local adaptation to either coastal or inland habitats. Our study is among the first to show repeated allelic variation across climatic clines in a non-model organism.
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Affiliation(s)
- Adriana I Hernández
- School of Integrative Plant Science, Section of Plant Biology and The L.H. Bailey Hortorium, Cornell University, Ithaca, New York, USA
| | - Chelsea D Specht
- School of Integrative Plant Science, Section of Plant Biology and The L.H. Bailey Hortorium, Cornell University, Ithaca, New York, USA
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Xiong ZR, Cobo M, Whittal RM, Snyder AB, Worobo RW. Purification and characterization of antifungal lipopeptide produced by Bacillus velezensis isolated from raw honey. PLoS One 2022; 17:e0266470. [PMID: 35385565 PMCID: PMC8985968 DOI: 10.1371/journal.pone.0266470] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/21/2022] [Indexed: 01/22/2023] Open
Abstract
Raw honey contains a diverse microbiota originating from honeybees, plants, and soil. Some gram-positive bacteria isolated from raw honey are known for their ability to produce secondary metabolites that have the potential to be exploited as antimicrobial agents. Currently, there is a high demand for natural, broad-spectrum, and eco-friendly bio-fungicides in the food industry. Naturally occurring antifungal products from food-isolated bacteria are ideal candidates for agricultural applications. To obtain novel antifungals from natural sources, we isolated bacteria from raw clover and orange blossom honey to evaluate their antifungal-producing potential. Two Bacillus velezensis isolates showed strong antifungal activity against food-isolated fungal strains. Antifungal compound production was optimized by adjusting the growth conditions of these bacterial isolates. Extracellular proteinaceous compounds were purified via ammonium sulfate precipitation, solid phase extraction, and RP-HPLC. Antifungal activity of purified products was confirmed by deferred overlay inhibition assay. Mass spectrometry (MS) was performed to determine the molecular weight of the isolated compounds. Whole genome sequencing (WGS) was conducted to predict secondary metabolite gene clusters encoded by the two antifungal-producing strains. Using MS and WGS data, we determined that the main antifungal compound produced by these two Bacillus velezensis isolates was iturin A, a lipopeptide exhibiting broad spectrum antifungal activity.
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Affiliation(s)
- Zirui Ray Xiong
- Department of Food Science, Cornell University, Ithaca, NY, United States of America
- * E-mail:
| | - Mario Cobo
- Department of Food Science, Cornell University, Ithaca, NY, United States of America
| | - Randy M. Whittal
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Abigail B. Snyder
- Department of Food Science, Cornell University, Ithaca, NY, United States of America
| | - Randy W. Worobo
- Department of Food Science, Cornell University, Ithaca, NY, United States of America
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Harvey CA, Pritts AA, Zwetsloot MJ, Jansen K, Pulleman MM, Armbrecht I, Avelino J, Barrera JF, Bunn C, García JH, Isaza C, Munoz-Ucros J, Pérez-Alemán CJ, Rahn E, Robiglio V, Somarriba E, Valencia V. Transformation of coffee-growing landscapes across Latin America. A review. Agron Sustain Dev 2021; 41:62. [PMID: 34484434 PMCID: PMC8406019 DOI: 10.1007/s13593-021-00712-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/28/2021] [Indexed: 06/01/2023]
Abstract
UNLABELLED In Latin America, the cultivation of Arabica coffee (Coffea arabica) plays a critical role in rural livelihoods, biodiversity conservation, and sustainable development. Over the last 20 years, coffee farms and landscapes across the region have undergone rapid and profound biophysical changes in response to low coffee prices, changing climatic conditions, severe plant pathogen outbreaks, and other drivers. Although these biophysical transformations are pervasive and affect millions of rural livelihoods, there is limited information on the types, location, and extent of landscape changes and their socioeconomic and ecological consequences. Here we review the state of knowledge on the ongoing biophysical changes in coffee-growing regions, explore the potential socioeconomic and ecological impacts of these changes, and highlight key research gaps. We identify seven major land-use trends which are affecting the sustainability of coffee-growing regions across Latin America in different ways. These trends include (1) the widespread shift to disease-resistant cultivars, (2) the conventional intensification of coffee management with greater planting densities, greater use of agrochemicals and less shade, (3) the conversion of coffee to other agricultural land uses, (4) the introduction of Robusta coffee (Coffea canephora) into areas not previously cultivated with coffee, (5) the expansion of coffee into forested areas, (6) the urbanization of coffee landscapes, and (7) the increase in the area of coffee produced under voluntary sustainability standards. Our review highlights the incomplete and scattered information on the drivers, patterns, and outcomes of biophysical changes in coffee landscapes, and lays out a detailed research agenda to address these research gaps and elucidate the effects of different landscape trajectories on rural livelihoods, biodiversity conservation, and other aspects of sustainable development. A better understanding of the drivers, patterns, and consequences of changes in coffee landscapes is vital for informing the design of policies, programs, and incentives for sustainable coffee production. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13593-021-00712-0.
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Affiliation(s)
- Celia A. Harvey
- Monteverde Institute, Apdo.69-5655, Monteverde, Puntarenas, Costa Rica
| | - Alyssa A. Pritts
- Farming Systems Ecology Group, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
| | - Marie J. Zwetsloot
- Soil Biology Group, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands
| | - Kees Jansen
- Rural Sociology Group, Wageningen University & Research, Hollandseweg 1, 6706 KN Wageningen, The Netherlands
| | - Mirjam M. Pulleman
- Soil Biology Group, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands
- The International Center for Tropical Agriculture (CIAT), Km 17 Recta Cali-Palmira, AA 6713, 763537 Cali, Colombia
| | - Inge Armbrecht
- Departamento de Biología, Universidad del Valle, Calle 13 # 100-00 ed, 320 Cali, Colombia
| | - Jacques Avelino
- CIRAD, UMR PHIM, San José, Costa Rica
- PHIM, Univ Montpellier, CIRAD, INRAE, Institut Agro, IRD, Montpellier, France
- Program of Agriculture, Livestock and Agroforestry, CATIE, Turrialba, 7170 Costa Rica
- IICA, 2200 Coronado, San José, AP 55 Costa Rica
| | - Juan F. Barrera
- Arthropod Ecology and Pest Management Group, Department of Agriculture, Society and Environment, El Colegio de la Frontera Sur, Carretera Antiguo Aeropuerto km 2.5, 30700 Tapachula, Chiapas Mexico
| | - Christian Bunn
- The International Center for Tropical Agriculture (CIAT), Km 17 Recta Cali-Palmira, AA 6713, 763537 Cali, Colombia
- University of Göttingen, Platz der Göttinger Sieben 5, 37073 Göttingen, Germany
| | - Javier Hoyos García
- Parque Tecnológico de Innovación TECNiCAFÉ, Cra 17 # 48 N 18 Casa 53 Conjunto Cerrado Entrepinos, Popayán, Cauca Colombia
| | - Carlos Isaza
- Programa de Café para Solidaridad en Colombia, Solidaridad, Calle 43 N, °23-78 Manizales, Colombia
| | - Juana Munoz-Ucros
- School of Integrative Plant Science, Cornell University, 236 Tower Rd, Ithaca, NY USA
| | - Carlos J. Pérez-Alemán
- Fundación Solidaridad Latinoamericana, Calle Evelio Lara No. 131-B, Ciudad del Saber, Ciudad de Panamá, Panamá
| | - Eric Rahn
- The International Center for Tropical Agriculture (CIAT), Km 17 Recta Cali-Palmira, AA 6713, 763537 Cali, Colombia
| | - Valentina Robiglio
- World Agroforestry Centre (ICRAF), c/o CIP, Av. La Molina 1895, P.O Box 1558, 12 Lima, Peru
| | - Eduardo Somarriba
- Program of Agriculture, Livestock and Agroforestry, CATIE, Turrialba, 7170 Costa Rica
| | - Vivian Valencia
- Farming Systems Ecology Group, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
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Davis AE, Deutsch KR, Torres AM, Mata Loya MJ, Cody LV, Harte E, Sossa D, Muñiz PA, Ng WH, McArt SH. Eristalis flower flies can be mechanical vectors of the common trypanosome bee parasite, Crithidia bombi. Sci Rep 2021; 11:15852. [PMID: 34349198 PMCID: PMC8338921 DOI: 10.1038/s41598-021-95323-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/22/2021] [Indexed: 11/17/2022] Open
Abstract
Flowers can be transmission platforms for parasites that impact bee health, yet bees share floral resources with other pollinator taxa, such as flies, that may be hosts or non-host vectors (i.e., mechanical vectors) of parasites. Here, we assessed whether the fecal-orally transmitted gut parasite of bees, Crithidia bombi, can infect Eristalis tenax flower flies. We also investigated the potential for two confirmed solitary bee hosts of C. bombi, Osmia lignaria and Megachile rotundata, as well as two flower fly species, Eristalis arbustorum and E. tenax, to transmit the parasite at flowers. We found that C. bombi did not replicate (i.e., cause an active infection) in E. tenax flies. However, 93% of inoculated flies defecated live C. bombi in their first fecal event, and all contaminated fecal events contained C. bombi at concentrations sufficient to infect bumble bees. Flies and bees defecated inside the corolla (flower) more frequently than other plant locations, and flies defecated at volumes comparable to or greater than bees. Our results demonstrate that Eristalis flower flies are not hosts of C. bombi, but they may be mechanical vectors of this parasite at flowers. Thus, flower flies may amplify or dilute C. bombi in bee communities, though current theoretical work suggests that unless present in large populations, the effects of mechanical vectors will be smaller than hosts.
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Affiliation(s)
- Abby E Davis
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA.
- Department of Environmental and Rural Science, The University of New England, Armidale, NSW, 2351, Australia.
| | - Kaitlin R Deutsch
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Alondra M Torres
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Mesly J Mata Loya
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Lauren V Cody
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Emma Harte
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - David Sossa
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Paige A Muñiz
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Wee Hao Ng
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Scott H McArt
- Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
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6
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Abstract
Every mammalian species harbours a gut microbiota, and variation in the gut microbiota within mammalian species can have profound effects on host phenotypes. In this review, we summarize recent evidence that gut microbiotas have influenced the course of mammalian adaptation and diversification. Associations with gut microbiotas have: (i) promoted the diversification of mammalian species by enabling dietary transitions onto difficult-to-digest carbon sources and toxic food items; (ii) shaped the evolution of adaptive phenotypic plasticity in mammalian species through the amplification of signals from the external environment and from postnatal developmental processes; and (iii) generated selection for host mechanisms, including innate and adaptive immune mechanisms, to control the gut microbiota for the benefit of host fitness. The stability of specific gut microbiotas within host species lineages varies substantially across the mammalian phylogeny, and this variation may alter the ultimate evolutionary outcomes of relationships with gut microbiotas in different mammalian clades. In some mammalian species, including humans, relationships with host species-specific gut microbiotas appear to have led to the evolution of host dependence on the gut microbiota for certain functions. These studies implicate the gut microbiota as a significant environmental factor and selective agent shaping the adaptive evolution of mammalian diet, phenotypic plasticity, gastrointestinal morphology and immunity. This article is part of the theme issue 'The role of the microbiome in host evolution'.
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Affiliation(s)
- Andrew H. Moeller
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jon G. Sanders
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Cornell Institute for Host-Microbe Interaction and Disease, Cornell University, Ithaca, NY 14853, USA
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Martínez C, Jaramillo C, Correa-Metrío A, Crepet W, Moreno JE, Aliaga A, Moreno F, Ibañez-Mejia M, Bush MB. Neogene precipitation, vegetation, and elevation history of the Central Andean Plateau. Sci Adv 2020; 6:eaaz4724. [PMID: 32923618 PMCID: PMC7455194 DOI: 10.1126/sciadv.aaz4724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 07/14/2020] [Indexed: 05/26/2023]
Abstract
Andean uplift played a fundamental role in shaping South American climate and species distribution, but the relationship between the rise of the Andes, plant composition, and local climatic evolution is poorly known. We investigated the fossil record (pollen, leaves, and wood) from the Neogene of the Central Andean Plateau and documented the earliest evidence of a puna-like ecosystem in the Pliocene and a montane ecosystem without modern analogs in the Miocene. In contrast to regional climate model simulations, our climate inferences based on fossil data suggest wetter than modern precipitation conditions during the Pliocene, when the area was near modern elevations, and even wetter conditions during the Miocene, when the cordillera was around ~1700 meters above sea level. Our empirical data highlight the importance of the plant fossil record in studying past, present, and future climates and underscore the dynamic nature of high elevation ecosystems.
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Affiliation(s)
- C. Martínez
- Plant Biology Section, School of Integrative Plant Sciences, Cornell University, 412 Mann Library Building, Ithaca, NY 14853, USA
- Smithsonian Tropical Research Institute, Unit 0948, APO AA 34002, Balboa, Ancon 084303092, Panama
| | - C. Jaramillo
- Smithsonian Tropical Research Institute, Unit 0948, APO AA 34002, Balboa, Ancon 084303092, Panama
- ISEM, U. Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - A. Correa-Metrío
- Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad de México 04520, México
| | - W. Crepet
- Plant Biology Section, School of Integrative Plant Sciences, Cornell University, 412 Mann Library Building, Ithaca, NY 14853, USA
| | - J. E. Moreno
- Smithsonian Tropical Research Institute, Unit 0948, APO AA 34002, Balboa, Ancon 084303092, Panama
| | - A. Aliaga
- Departamento de Paleontología de Vertebrados, Museo de Historia Natural LimaUNMSM, Av. Arenales 1256, Jesús María, Lima, Perú
| | - F. Moreno
- Earth and Environmental Sciences, University of Rochester, 227 Hutchison Hall, University of Rochester, Rochester, NY 14627, USA
| | - M. Ibañez-Mejia
- Earth and Environmental Sciences, University of Rochester, 227 Hutchison Hall, University of Rochester, Rochester, NY 14627, USA
| | - M. B. Bush
- Ocean Engineering and Marine Sciences, Florida Institute of Technology, 225 Harris Building, Melbourne, FL, 32901, USA
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Pegan TM, Craig DP, Gulson-Castillo ER, Gabrielson RM, Bezner Kerr W, MacCurdy R, Powell SP, Winkler DW. Solar-powered radio tags reveal patterns of post-fledging site visitation in adult and juvenile Tree Swallows Tachycineta bicolor. PLoS One 2018; 13:e0206258. [PMID: 30408052 PMCID: PMC6224047 DOI: 10.1371/journal.pone.0206258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/09/2018] [Indexed: 11/19/2022] Open
Abstract
The availability of small, lightweight tracking devices enhances our ability to study birds during mobile phases of their lives. Tree Swallows Tachycineta bicolor, a model species of wild songbird, are well-studied during their breeding season; but our understanding of their biology at other times of the year, when they are not tied to the fixed location of a nest, is more limited. We developed a lightweight radio tag with no battery (solar nanotag) to study the movements of small animals, and we deployed it to explore the behavior of Tree Swallows after the end of their summer breeding season. We tagged 32 breeding adult swallows and 36 juveniles and monitored their presence and absence at the breeding site during the post-fledging period. Although our observations are based on very small sample sizes, the tags revealed previously unknown patterns in Tree Swallow behavior during the post-breeding season. Some Tree Swallow fledglings continued to visit the site repeatedly in the months following the nesting season, with the latest detection occurring on September 30th; by contrast, all adults had permanently departed by the end of July. These results inform future hypotheses about post-breeding movements in Tree Swallows. But, more generally, the detection of tagged swallows on their distant wintering grounds, seven months after tagging, indicates the potential of studying small passerine movements throughout their entire lifetimes, and suggests a rich array of applications for these "Life Tags" to study the movements of small animals world-wide.
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Affiliation(s)
- Teresa M. Pegan
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States of America
| | - David P. Craig
- Department of Biology, Willamette University, Salem, OR, United States of America
| | - Eric R. Gulson-Castillo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States of America
| | - Richard M. Gabrielson
- Technology for Animal Biology and Environmental Research (TABER), Cornell University, Ithaca, NY, United States of America
| | - Wayne Bezner Kerr
- Technology for Animal Biology and Environmental Research (TABER), Cornell University, Ithaca, NY, United States of America
| | - Robert MacCurdy
- Technology for Animal Biology and Environmental Research (TABER), Cornell University, Ithaca, NY, United States of America
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, United States of America
| | - Steven P. Powell
- Technology for Animal Biology and Environmental Research (TABER), Cornell University, Ithaca, NY, United States of America
| | - David W. Winkler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States of America
- Technology for Animal Biology and Environmental Research (TABER), Cornell University, Ithaca, NY, United States of America
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Teeken B, Olaosebikan O, Haleegoah J, Oladejo E, Madu T, Bello A, Parkes E, Egesi C, Kulakow P, Kirscht H, Tufan HA. Cassava Trait Preferences of Men and Women Farmers in Nigeria: Implications for Breeding. Econ Bot 2018; 72:263-277. [PMID: 30573920 PMCID: PMC6267705 DOI: 10.1007/s12231-018-9421-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/18/2018] [Indexed: 05/21/2023]
Abstract
Nigeria is the world's largest cassava producer, hosting a diverse array of cassava farmers and processors. Cassava breeding programs prioritize "common denominator" traits in setting breeding agendas, to impact the largest possible number of people through improved varieties. This approach has been successful, but cassava adoption rates are less than expected, with room for improvement by integrating traits in demand by farmers and processors. This paper aims to inform breeding priority setting, by examining trait and varietal preferences of men and women cassava farmer/processors. Men and women in eight communities in Southwest and Southeast Nigeria were consulted using mixed methods. Women and men had significantly different patterns of cassava use in the Southwest. Fifty-five variety names were recorded from the communities demonstrating high genetic diversity maintained by growers, especially in the Southeast. High yield, early maturity, and root size were most important traits across both regions, while traits women and men preferred followed gender roles: women prioritized product quality/cooking traits, while men placed higher priority on agronomic traits. Trait preference patterns differed significantly between the Southeast and Southwest, and showed differentiation based on gender. Patterns of access to stem sources were determined more by region and religion than gender.
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Affiliation(s)
- Béla Teeken
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | | | - Joyce Haleegoah
- Council on Science and Industrial Research-Crops Research Institute (CSIR-CRI), Accra, Ghana
| | - Elizabeth Oladejo
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Tessy Madu
- National Root Crops Research Institute (NRCRI), Umudike, Nigeria
| | - Abolore Bello
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Elizabeth Parkes
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Chiedozie Egesi
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
- National Root Crops Research Institute (NRCRI), Umudike, Nigeria
- Cornell University, Ithaca, New York USA
| | - Peter Kulakow
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Holger Kirscht
- Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), Bonn, Germany
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Gildemyn S, Molitor B, Usack JG, Nguyen M, Rabaey K, Angenent LT. Upgrading syngas fermentation effluent using Clostridium kluyveri in a continuous fermentation. Biotechnol Biofuels 2017; 10:83. [PMID: 28367228 PMCID: PMC5372331 DOI: 10.1186/s13068-017-0764-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/18/2017] [Indexed: 05/07/2023]
Abstract
BACKGROUND The product of current syngas fermentation systems is an ethanol/acetic acid mixture and the goal is to maximize ethanol recovery. However, ethanol currently has a relatively low market value and its separation from the fermentation broth is energy intensive. We can circumvent these disadvantages of ethanol production by converting the dilute ethanol/acetic acid mixture into products with longer carbon backbones, which are of higher value and are more easily extracted than ethanol. Chain elongation, which is the bioprocess in which ethanol is used to elongate short-chain carboxylic acids to medium-chain carboxylic acids (MCCAs), has been studied with pure cultures and open cultures of microbial consortia (microbiomes) with several different substrates. While upgrading syngas fermentation effluent has been studied with open cultures, to our knowledge, no study exists that has performed this with pure cultures. RESULTS Here, pure cultures of Clostridium kluyveri were used in continuous bioreactors to convert ethanol/acetic acid mixtures into MCCAs. Besides changing the operating conditions in regards to substrate loading rates and composition, the effect of in-line product extraction, pH, and the use of real syngas fermentation effluent on production rates were tested. Increasing the organic loading rates resulted in proportionally higher production rates of n-caproic acid, which were up to 40 mM day-1 (4.64 g L-1 day-1) at carbon conversion efficiencies of 90% or higher. The production rates were similar for bioreactors with and without in-line product extraction. Furthermore, a lower ethanol/acetic acid ratio (3:1 instead of 10:1) enabled faster and more efficient n-caproic acid production. In addition, n-caprylic acid production was observed for the first time with C. kluyveri (up to 2.19 ± 0.34 mM in batch). Finally, the use of real effluent from syngas fermentation, without added yeast extract, but with added defined growth factors, did maintain similar production rates. Throughout the operating period, we observed that the metabolism of C. kluyveri was inhibited at a mildly acidic pH value of 5.5 compared to a pH value of 7.0, while reactor microbiomes perform successfully at mildly acidic conditions. CONCLUSIONS Clostridium kluyveri can be used as a biocatalyst to upgrade syngas fermentation effluent into MCCAs at pH values above 5.5.
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Affiliation(s)
- Sylvia Gildemyn
- Cornell University, Biological and Environmental Engineering, Riley-Robb Hall, Ithaca, NY 14853 USA
- Ghent University, Center for Microbial Ecology and Technology (CMET), Coupure Links 653, 9000 Ghent, Belgium
- Organic Waste SystemsDok Noord 5, 9000 Ghent, Belgium
| | - Bastian Molitor
- Cornell University, Biological and Environmental Engineering, Riley-Robb Hall, Ithaca, NY 14853 USA
| | - Joseph G. Usack
- Cornell University, Biological and Environmental Engineering, Riley-Robb Hall, Ithaca, NY 14853 USA
| | - Mytien Nguyen
- Cornell University, Biological and Environmental Engineering, Riley-Robb Hall, Ithaca, NY 14853 USA
| | - Korneel Rabaey
- Ghent University, Center for Microbial Ecology and Technology (CMET), Coupure Links 653, 9000 Ghent, Belgium
| | - Largus T. Angenent
- Cornell University, Biological and Environmental Engineering, Riley-Robb Hall, Ithaca, NY 14853 USA
- University of Tübingen, Center for Applied GeoSciences, Hölderlinstr. 12, 72074 Tübingen, Germany
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