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Alan T. Critchley

Alan T. Critchley
Verschuren Centre for Sustainability in Energy and Environment

About

260
Publications
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Introduction
Currently reviewing research in Marine Biology, Botany and Phycology. A recent project, now finalized, was a book for Springer on the cultivation/utilisation of Kappaphycus and Eucheuma seaweeds with Drs Anicia Hurtado and Iain Neish as co-editors. We are very pleased with outcome and thank all contributors most sincerely. A project entitled SEECS - " seaweed extracts for enhanced cultivation of seaweeds" will be updated with a major review by Dr Anicia Hurtado very soon. Will also add some preliminary details about a seaweed resources of the world publication project in the very near future.

Publications

Publications (260)
Article
Seaweed-derived extracts are commonly used as biostimulants in agriculture and, more recently, to cultivate other types of seaweeds. Here, we examined if Ascophyllum marine plant extract powder (aka AMPEP) and Kelpak® influenced changes in the life history of the commercially important, Neopyropia yezoensis. N. yezoensis was cultured in von Stosch...
Article
A R T I C L E I N F O Keywords: Alzheimer's disease Drosophila melanogaster Flavonoid-rich ascophyllum nodosum Mitochondrial Oxidative stress A B S T R A C T Background: In Alzheimer Disease (AD) pathogenesis, aggregation of Aβ 42 fibrils strongly correlates with memory dysfunction and neurotoxicity. Till date, no promising cures for AD. Report sho...
Article
Full-text available
Sargassum thunbergii is a brown macroalga endemic to the northwest Pacific. It plays important ecological roles in the structure and maintenance of coastal marine ecosystems. The bioactive compounds extracted from S. thunbergii have been extensively documented for potential use in anti-obesity, anti-inflammatory activity, anti-tumor, anti-oxidant a...
Article
Background: In Alzheimer Disease (AD) pathogenesis, aggregation of Aβ42 fibrils strongly correlates with memory dysfunction and neurotoxicity. Till date, no promising cures for AD. Report shows that flavonoids contributed anti-oxidant, anti-cancer and neuroprotection activity by regulating the mitochondrial machinery. Here, we first report the iden...
Article
The use of seaweed extracts as biostimulants to promote enhancements in other seaweed crops is gaining momentum. Here we examined if the seaweed-derived biostimulant Ascophyllum marine plant extract powder - AMPEP, enhanced growth and thermal tolerance of cultured thalli of Neopyropia yezoensis when grown under optimal and sub-optimal temperature c...
Article
Full-text available
Highlights 1. This policy brief highlights key challenges that must be addressed for the long-term sustainability of the global seaweed industry, ensuring its role in providing nature-based solutions within the sustainable ocean economy agenda and in contributing to the UN Decade of Ocean Science for Sustainable Development (2021-2030). 2. Seaweed...
Technical Report
Full-text available
Cottier-Cook, E.J., Nagabhatla, N., Asri, A., Beveridge, M., Bianchi, P., Bolton, J., Bondad-Reantaso, M.G., Brodie, J., Buschmann, A., Cabarubias, J., Campbell, I., Chopin, T., Critchley, A., De Lombaerde, P., Doumeizel, V., Gachon, C.M.M., Hayashi, L., Hewitt, C.L., Huang, J., Hurtado, A.Q., Kambey, C., Kim, G.H., Le Masson, V., Lim, P.E., Liu, T...
Article
Full-text available
Extracts from the brown seaweed, Ascophyllum nodosum (ANE), are extensively used as plant biostimulants. Ascophyllum nodosum extracts, as applied to plants, impart resistance/tolerance against various abiotic and biotic stresses due to the presence of multiple biological primers and elicitors. However, little information is available on the effects...
Article
Full-text available
In the present study, the effect of a commercial extract of the seaweed Ascophyllum nodosum on in vitro micropropagation, shoot regeneration, and rhizoghenesis were studied in Nicotiana benthamiana and Prunus domestica. Results showed that the MS medium supplemented with various concentrations of the Ascophyllum extract (5, 10, 50, and 100 mg L−1)...
Article
Extracts from the brown seaweed, Ascophyllum nodosum (ANE), are extensively used as plant biostimulants. Ascophyllum nodosum extracts, as applied to plants, impart resistance/tolerance against various abiotic and biotic stresses due to the presence of multiple biological primers and elicitors. However, little information is available on the effects...
Article
Full-text available
The cover image is based on the Review Article Kelp aquaculture in China: A retrospective and future prospects by Zi-Min Hu et al., https://doi.org/10.1111/raq.12524.
Article
Full-text available
To exploit the nutraceutical and biomedical potential of selected seaweed-derived polymers in an economically viable way, it is necessary to analyze and understand their quality and yield fluctuations throughout the seasons. In this study, the seasonal polysaccharide yield and respective quality were evaluated in three selected seaweeds, namely the...
Chapter
Biostimulants are any substances (e.g., humic or fulvic acids, vermicompost leachate, seaweed extracts, smoke-water, protein hydrolyzates amino acids, betaines, polysaccharides, phosphites, polyamines, and chitosan) or microorganisms (e.g., microalgae, beneficial bacteria, or fungi) that stimulate natural process within a plant and can be applied t...
Chapter
Full-text available
A plant biostimulant is any substance or microorganism which can be applied to plants to enhance seed germination and plant growth development along with its nutritional efficiency. Plant biostimulants collectively influence: plant growth development, pollen tube development, flower and fruit set, plant pigments, shoot and root development, nutriti...
Chapter
Biostimulants, in general, and seaweed extracts, in particular, have been progressively accepted into agronomic programs over the past 25 years. Products that were once considered “snake oil” or ineffective elixirs have steadily secured increasingly larger portions of the agricultural products market. This progression only occurred through collecti...
Article
Full-text available
Globally, China has the largest scale of kelp cultivation and production operations. However, its kelp aquaculture industry is suffering from declining germplasm diversity, degradation of agronomic traits, the presence of polluted environments, changing ocean conditions and increasing anthropological interference. This review covers two of the most...
Article
Full-text available
Seaweeds (macroalgae) are, together with microalgae, main contributors to the Earth's production of organic matter and atmospheric oxygen as well as fixation of carbon dioxide. In addition, they contain a bounty of fibres and minerals, as well as macro-and micronutrients that can serve both technical and medicinal purposes, as well as be a healthy...
Article
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Sustainable agricultural practices increasingly demand novel, environmentally friendly compounds which induce plant immunity against pathogens. Stimulating plant immunity using seaweed extracts is a highly viable strategy, as these formulations contain many bio-elicitors (phyco-elicitors) which can significantly boost natural plant immunity. Certai...
Chapter
Most of the world’s seaweed-derived extracts used for their biostimulatory/bioeffector properties for plants (i.e., abiotic and biotic stress reduction) are manufactured from brown algae, generally harvested from wild populations, or collected as storm-cast (e.g., Ascophyllum, Durvillaea, Ecklonia, Laminaria/Saccharina, Sargassum, etc.). Extracts o...
Chapter
A plethora of papers and book chapters have been published wherein the effects of biostimulants on plant growth and development, resistance to biotic and abiotic stress, crop yield and food quality were examined. Natural biostimulants are known to stimulate yield and quality, photochemical efficiency and to protect the photosynthetic pigments. In t...
Article
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Snakebites are a serious occupational problem affecting rural populations of tropical and sub-tropical, developing countries. Envenomation caused by the snakes Bothrops jararaca and B. jararacussu is characterized by local pain, edema, hemorrhage, tissue necrosis, and death. Despite the fact that antivenom may prevent the death of bite victims, tre...
Article
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Ascophyllum nodosum is a large and common brown alga. The fronds are olive-brown but can appear yellowish when stressed. It is a common, intertidal species around the periphery of the North Atlantic Ocean. It is particularly common on the northwestern coast of Europe (from Svalbard to Portugal), including east Greenland, Iceland and the NE coast of...
Method
Eucheumatoids is the collective name of red seaweeds belonging to the genera Kappaphycus and Eucheuma. These two red seaweeds are endemic to tropical waters within latitudes 20° north and south of the Equator. Commercial cultivation of these red seaweeds was pioneered in the Philippines in the early 1970s using vegetative thalli (Doty 1973). To dat...
Article
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Can be viewed at: https://rdcu.be/b4phC Seaweeds have been around since well before the dawn of mankind and have had varying degrees of influence on societies throughout history. Today, they have a well-established position of value after much scientific endeavour and commercialisation of applications. In the distant past, however, seaweeds were s...
Article
Full-text available
Gracilaria spp. (agarophytes) are cultivated by Panamanian communities to use directly as food and as important components of traditional medicines and remedies. These uses are part of the traditional culture of both the Guna Indians and the Afro-Antillean communities. One driving force to better understand the biology of the various species of Gra...
Article
Full-text available
Marine macroalgae (seaweeds), are amongst the first multicellular organisms and, as such, the precursors to land plants. By the time ‘land’ animals arrived on the scene, terrestrial plants were plentiful and varied, and herbivorous diets developed in concert with the food sources most commonly available. However, skip forward several hundred millen...
Article
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Seaweeds comprise ca. 12,000 species. Global annual harvest is ca. 30.13 million metric tonnes, (valued ca. $11.7 billion USD in 2016) for various commercial applications. The growing scope of seaweed-based applications in food, agricultural fertilizers, animal feed additives, pharmaceuticals, cosmetics and personal care is expected to boost market...
Article
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Poultry and its products are an economical source of high-quality protein for human consumption. In animal agriculture, antibiotics are used as therapeutic agents to treat disease in livestock, or as prophylactics to prevent disease and in so doing enhance production. However, the extensive use of antibiotics in livestock husbandry has come at the...
Article
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Four strains of Kappaphycus spp. (viz. K. alvarezii-tambalang brown and green, K. striatus-sacol green) and K. malesianus (aring-aring) were grown in Semporna, Sabah, for three consecutive growth cycles from August 2018 to January 2019, each for a duration of 45 days. The study was established in order to determine the impacts of a commercially pro...
Article
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Eucheumatopsis isiformis Núñez-Resendiz, Dreckmann & Sentíes is a red alga with great economic potential due to its iota-carrageenan content that could serve as a substitute for traditional carrageenan sources (Freile-Pelegrín and Robledo, J Appl Phycol 20:537–541, 2008) such as the red alga Kappaphycus alvarezii (Loureiro et al., New Phytol 206:48...
Article
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Presently, there is lack of a vaccine that would lead to immunization against the virus COVID-19, but here are some of the characteristics that various seaweeds have and which may provide a glimpse into potential solutions of this global health problem in the near future and possibly forearm us for any future such pandemics. Many species of marine...
Article
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The increasing demands for seaweeds have promoted the designation of the seaweed industry as the third Entry Point Project (EPP) under the National Key Economic Area (NKEA) initiative of the Economic Transformation Programme (ETP) of the Malaysian government. The farming of carrageenophytes has emerged as a successful enterprise and provides a prom...
Chapter
Full-text available
Abstract A detailed understanding of physiological and reproductive processes in seaweeds has repeatedly proven to be an essential pre-requisite in the successful development of a sustainable industry. The prime example of this was the classical discovery of the “conchocelis”- phase of Pyropia (Porphyra) by Kathleen Mary Drew-Baker in 1949. Such el...
Article
The science of seaweeds (i.e., phycology, the study of algae including macroalgae) is many centuries old. Indeed, some of the earliest taxonomic names using the binomial system, as applied by Linnaeus to any living thing were given to common seaweeds (i.e., Fucus). The taxonomic work was soon followed by studies on their biology (structure and repr...
Article
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As the world prepares to live the year 2020, this series of special issues published by Botanica Marina, highlighting world seaweed resources has, indeed, proven to be rich fodder for visionaries. Its production and publication coincide with a time when social justice movements across the world have become united around global environmental issues...
Chapter
Contents 1. Introduction 2. The current status of seaweed resources in the Philippines 22 3. Brief descriptions, local distribution and uses of red seaweeds with emerging potential applications 4. Sustainable harvesting and utilization of biomass removed from natural populations 5. Biochemical compositions 5.1 Protein and amino acids 5.2 Carbohy...
Chapter
Biostimulants are increasingly and extensively applied for the benefit of enhanced, terrestrial agronomic production, crop health and quality. Extracts of various seaweeds are classified as important biostimulatory inputs. Various seaweeds are important marine crops, with multiple phyconomic values. However, as with their terrestrial counterparts,...
Article
Full-text available
Background: Intermittent dehydration caused by tidal changes is one of the most important abiotic factors that intertidal seaweeds must cope with in order to retain normal growth and reproduction. However, the underlying molecular mechanisms for the adaptation of red seaweeds to repeated dehydration-rehydration cycles remain poorly understood. Re...
Article
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The biosorption capacities of dried meal and a waste product from the processing for biostimulant extract of Ascophyllum nodosum were evaluated as candidates for low-cost, effective biomaterials for the recovery of indium(III). The use of indium has significantly grown in the last decade, because of its utilization in hi-tech. Two formats were eval...
Article
Kappaphycus and Eucheuma, known collectively as ‘eucheumatoids’, are two related genera of red seaweeds which currently lead the rankings for volume of global production of farmed macroalgae. Since 2009, the combined cultivated volume of these carrageenophytes overtook that of the brown seaweeds Laminaria (Saccharina) and Undaria for global product...
Chapter
Recent advances in the use of on-land nurseries for commercial production and out-planting of Kappaphycus seedlings, a carrageen-bearing seaweed Anicia Q. Hurtado1* and Alan T. Critchley2 1 Integrated Services for the Development of Aquaculture and Fisheries MacArthur Highway, Tabuc Suba, Jaro Iloilo City 5000, Philippines 2 Verschuren Centre for...
Article
Full-text available
Extracts of the brown alga, Ascophyllum nodosum, are widely used as plant biostimulants to improve growth and to impart tolerance against abiotic stresses. However, the molecular mechanisms by which A. nodosum extract (ANE) mediates stress tolerance are still largely unknown. The aim of this study was to study selected anti-stress mechanisms at the...
Article
Full-text available
Extracts of brown algae are used commercially for agricultural crops due to their plant growth-promoting effects and they can also be applied to help improve seaweed cultivation. Gracilaria caudata is commercially exploited as a raw material for agar production in Brazil, and Laurencia catarinensis is a source of halogenated terpenoids with several...
Article
Full-text available
In this modern age, seaweeds (macroalgae) are deemed to be “sexy” and seem to be used for almost anything and everything. The traditional range of applications spans sea vegetables to raw materials used as sources of gels in processed foods (i.e. phycocolloids, such as carrageenans, alginates and agar), to fertilizers and biologically active extrac...
Article
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Abiotic and biotic stresses limit the growth and productivity of plants. In the current global scenario, in order to meet the requirements of the ever-increasing world population, chemical pesticides and synthetic fertilizers are used to boost agricultural production. These harmful chemicals pose a serious threat to the health of humans, animals, p...
Article
Abiotic and biotic stresses limit the growth and productivity of plants. In the current global scenario, in order to meet the requirements of the ever-increasing world population, chemical pesticides and synthetic fertilizers are used to boost agricultural production. These harmful chemicals pose a serious threat to the health of humans, animals, p...
Article
Full-text available
Over the past century or more, traditional uses of seaweeds began and initially comprised the simple collection, sorting and drying of seaweeds harvested from the wild, or cast upon the beach, for use as soil “manure/fertilizer/improver”. Some macroalgae were used for unprocessed food purposes and subsequently harvested and cultivated biomasses of...
Article
Full-text available
The study of bioactive components of the brown alga Ascophyllum nodosum (L.) Le Jolis has shown that they promote growth and increase productivity of plants. However, a standardized model system providing consistent responses to such bioactive components has yet to be established. Given that freezing stress, especially in northern climates, reduces...
Article
As the primordial, prokaryotic inhabitants on Earth, microbial entities were responsible for significant influences on the pathways taken in the development of life as we know it. The manifestation of numerous pathologies in humans is considered to be intrinsically associated with microbial dysbiosis in the gut (i.e. a poorly balanced microbiota)....
Chapter
Seaweeds have been used for centuries as organic inputs to improve soil properties and more recently extracts of seaweeds have been used as biostimulants to enhance the growth of agricultural crops. However, their potential as biocontrol agents, as used to suppress plant diseases, has not been broadly exploited, due to the lack of cohesive scientif...
Article
Full-text available
Ascophyllum nodosum extract (ANE) contains bioactive compounds that improve the growth of Arabidopsis in experimentally-induced saline conditions; however, the molecular mechanisms through which ANE elicits tolerance to salinity remain largely unexplored. Micro RNAs (miRNAs) are key regulators of gene expression, playing crucial roles in plant grow...
Data
MA plot of distribution of differentially expressed genes in Arabidopsis between the various treatments at 12 h. C: Control, T1: ANE, T2: ANE+NaCl, T3: NaCl. (TIF)
Data
(a) Average number of reads (in millions) obtained from sequencing the libraries from control and the 3 treatments (ANE, ANE+NaCl and NaCl) after 6 and 12 h of treatment. (b) Average number of miRNA mapped to the Arabidopsis genome in the libraries from control and the three treatments. Error bars represent SE. (TIF)
Data
Size distribution of miRNA sequences in the libraries from control and the three treatments (ANE, ANE+NaCl and NaCl), constructed from the leaves of Arabidopsis after 6 h (a) and 12 h (b) of treatment. (TIF)
Data
MA plot of distribution of differentially expressed genes in Arabidopsis between the various treatments at 6 h. C: Control, T1: ANE, T2: ANE+NaCl, T3: NaCl. (TIF)
Data
List of the primers used in target gene expression analysis. (DOCX)
Data
Three-week-old Arabidopsis plants before being supplemented with water (a), 100 mM NaCl (b), 0.1% ANE (c), and 0.1% ANE with 100 mM NaCl (d). (TIF)
Data
ANE improves growth of Arabidopsis in the presence of salinity. The effects of ANE in absence and presence of salinity stress on the in vitro growth of 7 days old Arabidopsis seedlings grown in ½ MS media (a) or supplemented with 100 mM NaCl (b), 0.1% ANE (c), and 0.1% ANE with 100 mM NaCl (d). The effect of ANE on the fresh (e) and dry weight (f)...
Data
ANE modulates root system architecture of Arabidopsis in the presence of salinity. The effects of ANE in absence and presence of salinity stress on root system architecture of Arabidopsis seedlings grown on in vitro conditions. (a) The effect of ANE on the primary root length, (b) average length and (c) the number of lateral roots of Arabidopsis se...
Data
The effects of ANE in absence and presence of salinity stress and of phosphate on the in vitro improves the growth of 7 days old Arabidopsis seedlings supplemented with 0 mM NaCl (a), 0.01% ANE (b), 100 mM NaCl (c), and 0.01% ANE with 100 mM NaCl (d) and phosphate starved media with 0 mM NaCl (e), 0.01% ANE (f), 100 mM NaCl (g), and 0.01% ANE with...
Data
Na+, K+, K+/Na+ ratio and P content of the Arabidopsis grown in the presence of control, ANE (T1), ANE+NaCl (T2) and NaCl (T3). (DOCX)