Bulletin Number 10. January 31st, 2014
|Dr. Jean Michel Savoie
Growers and spawn makers continuously search for varieties and strains of mushrooms with improved qualities. The sought after qualities may be found in wild strains of the species, but they are unlikely to be found in a combination that is commercially desirable . It is possible to combine the desirable traits through selective breeding, but breeding usually requires considerable investment in time and resources. Consequently, breeders may be reluctant to commit to the development of a new variety if they know it will be difficult to cover their investment due to lack of protection of the new variety or strain. On the other hand, patenting living organisms that are used for human food that could contribute to improved food security is a subject of discussion from an ethical point of view. During the 7th International Conference on Mushroom Biology and Mushroom Products (ICMBMP7) hosted by the INRA research group in Arcachon (France) in 2011, a round table discussion was held on "Regulation for the protection of new mushroom varieties". A representative of the International Union for the Protection of New Varieties of Plants (UPOV) was invited to the discussion. UPOV is an intergovernmental organization established by a convention in Paris in 1961 that was most recently revised in 1991.
INRA, UR1264, Mycology and Food Safety,
BP81, F-33883 Villenave d´Ornon, France
For consideration for protection as a new variety, variety A must satisfy three criteria for the DUS (Distinctiveness, Uniformity, and Stability system as follows:
- Breeder exemption: anyone can use variety A for breeding of a new variety (by crossing with another variety). Authorization is not required.
- Experimentation and Research are free with variety A.
- No restriction for private use and for non-commercial purpose; for example, use by amateur gardeners and subsistence farmers.
This system might be a compromise between the protection encouraging breeders to develop new varieties by expecting a return on investment, and the global qualitative and quantitative improvement of food production as common public goods that should benefit the welfare of mankind.
The protection of varieties of the button mushroom, Agaricus bisporus, concerns breeders. The first hybrid A. bisporus strains (Horst-U1, -U3) were developed in The Netherlands in the 1980´s. In recent studies using microsatellite markers or SNPs, it was shown that almost all hybrids commercialized over the last 20 years have no or very few differences with U1 or U3 [2, 3]. However, they are not all direct copies. In hybrids that seemed to be genetically identical to Horst-U1 at the heterokaryotic level, the analyses of each constituting nuclei have demonstrated allelic rearrangements . Are these allelic rearrangements the result of significant work of a secondary breeder that could enter in the breeder exception of the UPOV breeder´s rights?
Due to the life cycle of A. bisporus, most of the spores produced by a fruiting body are heterokaryotic containing compatible nuclei and are able to produce fruiting bodies without first mating. These spores are produced after a short phase of karyogamy followed by meiosis separating the two nuclei (Fig. 1). During these events, allelic rearrangements may occur and lead to small changes in the phenotype of the fruiting bodies arising from the spore, without changes in the genetic background. New phenotypes can be selected after a round of screening, but they are directly derived from the genotype giving the spores used. When the genotype at the origin of the new derived phenotype is a hybrid, is this selection work enough to not infringe the rights of the first
breeder who obtained the hybrid? This kind of question was taken into account in the 1991 revision of the UPOV convention by including the Essential Derived Varieties (EDV) in the Breeder´s Rights.
Consequently, the secondary breeder producing an EDV has to negotiate with the primary breeder before selling it as a new variety, but defining when there is an essential derivation between two varieties is not so easy. To prevent further conflicts and long procedures, a consensus has to be generated within the mushroom industry on the definition of an EDV and how to demonstrate its statute. This has been done by a number of seed federations with definitions of what should be considered as an EDV adapted to the biology of their species. For initiating the thought with A. bisporus, a working group has recently been formed in Europe with representatives of research groups of Wageningen UR (The Netherlands) and INRA Bordeaux (France), and of the spawn industry: Amycel, Limgroup, Sylvan.
Fig. 1. Dominant Life cycle of Agaricus bisporus in which derived varieties can be obtained from fertile spores, without sex.
|UPOV´s mission is "to provide and promote an effective system of plant variety protection, with the aim of encouraging the development of new varieties of plants, for the benefit of society". It is not well known, but edible mushroom varieties may be protected in most countries via the UPOV convention.
UPOV grants to breeders an intellectual property right differing from patents. There are no restrictions on who may be considered a breeder under the UPOV system: a breeder might be an individual, a farmer, a researcher, a public institute, a private company, etc...
The intention of the working group is to publish a position paper in a scientific journal that describes how EDVs can be generated due to the typical life cycle of A. bisporus and to propose delimitations of EDV definition. It would be used as a reference for protection of new varieties to be delivered in the future after its publication, but it will have no consequence on present-day varieties. With this initiative the ambition of the working group is to generate worldwide support on the EDV issue for the button mushroom. Relevant parties are encouraged to share their views and contribute to the activities of the working group. Comments from readers of the Bulletin of the World Society for Mushroom Biology and Mushroom Products are most welcome.
The contact person of the working group is:
Dr. Anton S.M. Sonnenberg
P.O. Box 16
6700 AA Wageningen>/br>
Phone: +31 317 481336
 Savoie JM (2013) Biological resources and breeding for improvements in the production of the button mushroom in small-scale farming. WSMBMP Bulletin 8. http://wsmbmp.org/Bulletin_8_Content.html
 Foulongne-Oriol M, Rodier A, Caumont P, Spataro C, Savoie JM (2011) Agaricus bisporus cultivars: hidden diversity beyond apparent uniformity? Proceedings of the 7th International conference on Mushroom Biology and Mushroom Products. Volume 2. Savoie JM, Foulongne-Oriol M, Largeteau M, Barroso G (eds) 9-16. http://wsmbmp.org/Previous_Conference_7.html
 Sonnenberg ASM, Baars JP, Hendrickx PM, Lavrijssen B, Gao W, Weijn A, Mes JJ (2011) Breeding and strain protection in the button mushroom Agaricus bisporus. In Savoie JM, Foulongne-Oriol M, Largeteau M, Barroso G (eds), Proceedings of the 7th international conference on mushroom biology and mushroom products, 1:7-15. http://wsmbmp.org/Previous_Conference_7.html
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Dr. Jan I. Lelley,
Inst. for Mushroom Research
In Germany, mushrooms, especially the common mushroom (Agaricus bisporus), are generally cultivated in modern enterprises. The growing areas are air-conditioned so that the temperature, humidity, airflow and air quality are regulated by suitable computer-controlled technology. The growth substrate consists largely of horse manure, poultry manure and cereal straw. Lime and gypsum are used for regulating the pH of the substrate and its structure.
The growth substrate undergoes a fermentation process comprising several phases. It is then inoculated with high-quality mushroom spawn and spread in layers ~16 cm thick on tiered shelf beds. After it has been completely colonised by the mushroom mycelium, the substrate is covered with a layer of peat 5 cm thick. Harvesting commences 18-20 days after application of the peat layer and lasts for 2-3 weeks. During this period, up to 30 kg of mushrooms are harvested from each square metre of substrate surface. There are about 30 major mushroom growers throughout the country.
Germany´s mushroom industry is not large
Although mushroom cultivation in Germany began back in the middle of the 19th Century, and Germans´ per capita annual mushroom consumption of 3.2 kg is one of the highest, the quantity of mushrooms produced in the country is not very large. In 2012, production was nearly 62,000 tons, well below the production figures of the leading European nations such as Poland (238,000 tons), the Netherlands (250,000 tons), France (108,000 tons) and Spain (98,000 tons).
Based on a survey by the German Mushroom and Edible Fungus Growers Association, to which nearly all German mushroom growers belong, 54,000 tons of the total production was sold on fresh markets and 8,000 tons in processed form.
These production levels remained stable compared to the previous year, although some producers have expanded their capacity while others have ceased mushroom production altogether. Since the previous year yielded very poor straw, which (along with horse manure) is the basis of the mushroom cultivation substrate, net revenues for the past two years were slightly lower than usual.
The key edible fungus cultivated in Germany is still the common mushroom (A. bisporus). Although other cultivated fungi such as the king oyster mushroom (Pleurotus eryngii), the oyster mushroom (Pleurotus ostreatus) and shiitake (Lentinula edodes) are slowly catching up, production of these mushrooms in Germany for the year 2012 totalled only about 2,000 tons.
Mushroom consumption is increasing slowly but steadily
In 2011, sales of fresh mushrooms in Germany increased by nearly 2% following an 8% rise in the previous year. In 2010, a generally tight supply of vegetables in the country had a distinctly stimulating effect on the market for the common mushroom, by far the most important fungal species. When the food trade was searching for cheap promotional items in 2010, they often resorted to mushrooms. This additional impulse faded away in 2011 because fresh vegetables were conveniently available throughout the year. Nevertheless, sales rose by 2%, in line with the growth rate for fresh vegetables overall.
Consumer prices for mushrooms have now risen again slightly after a drop in 2010. Consumer spending grew by almost 5%, which is clearly a better result compared to that for fresh vegetables (-4%).
A point worth noting is that demand for chestnut mushrooms is increasing slowly but steadily in Germany. According to Mr Jochen Winkhoff, General Manager of the German Mushroom and Edible Fungus Growers Association, the high point of the market for chestnut mushrooms is generally reached in the autumn. Since chestnut mushrooms have a higher dry matter content, their taste is particularly intense. A survey of distributors in the trade press suggests that the increasing consumption of chestnut mushrooms is not to the detriment of the classic white varieties.
Therefore, it is possible to state that there is a slow increase in the overall consumption of mushrooms in Germany. This trend is also supported by the relevant statistics.
The trend towards buying chestnut mushrooms continued in 2011 and 2012. Market share by volume purchased increased from 19% to almost 22%. In terms of expenditure, it is now as much as 29%. The market share of organic mushrooms has increased too, but their proportion of overall mushroom consumption is still low. The share of organic products is now just under 3% of the volume of fresh mushrooms purchased. It is over 6% in terms of spending, although most of the organic mushrooms sold are of the more expensive chestnut variety.
The majority of mushrooms consumed are imported
A good 50% of the fresh mushrooms consumed in Germany are imports. As already stated, domestic production for the fresh market is about 54,000 tons. Of this, however, approximately 6,000 tons are exported. An additional 8,000 tons of German mushrooms are processed.
Imports of fresh mushrooms were about 62,000 tons in both 2011 and 2012. The Netherlands and Poland are the main suppliers of fresh mushrooms, each accounting for approximately 30,000 tons. Hungary follows in third place, but with only 500 tons.
Hardly any other edible mushrooms are imported into Germany in any quantity. One exception is fresh chanterelles, large quantities of which are brought in from eastern Europe (Poland, Belarus and the Baltic States).
Consumption of processed mushrooms is declining
Sales of preserved mushrooms have been declining in recent years. This is shown by data from various trade organisations. Depending on the source, the level of annual decline is put at between 5% and 6%. Over the past eight years, the statistics show a 22% decline in the volume of processed mushroom sales. The proportion of households buying processed mushrooms has decreased during this period by 8% to 59%. At the same time, the frequency of such purchases dropped, although the amount spent per purchase hardly changed. This is essentially dictated by the package sizes. Consumer prices for preserved mushrooms have remained stable in recent years; compared to 2003, they have risen by over 25%.
The future prospects for the German mushroom industry seem favourable and we anticipate a further increase in mushroom consumption in Germany. The reason is that people are realising that mushrooms are a healthy food. This recognition is spreading, along with the well-known idea that regular consumption of fruit and vegetables is healthy.
However, it is not expected that the rising mushroom consumption in Germany will lead to a significant increase in German mushroom production. The existing mushroom industry will be able to hold its own well into the future, but increasing consumer demand is expected to be covered mostly by higher exports to Germany by foreign mushroom producers.
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Laboratory of Mycology and Mushroom Cultivation.
Instituto de Investigaciones Biotecnológicas-
Instituto Tecnológico Chascomús (UNSAM-CONICET),
CP 7130, Chascomús, Buenos Aires, Argentina.
New strains and new species
One of the problems in mushroom production is that commercial strains sometimes decline in their production performance after several consecutive subcultures or a long period of storage in culture medium, leading to a reduction in yield. Biological efficiencies (BE) may sometimes be increased by optimization of cultural conditions, such as combining different substrates or adding nutritional supplements. However, these practices are not always successful in recovering the production of a commercial strain´s performance. An alternative solution for coping with declining productivity of a long-used strain could be collecting and evaluating new natural occurring strains, that are more productive with more desirable quality aspects. Additionally, there are many edible mushrooms, worldwide, that are mostly known and consumed by "micophagous" people in each region. It is also interesting to use this "popular knowledge" and search for these "new" naturally occurring species that could be intensively produced in mushroom farms increasing the availability of new mushroom products. This is the primary reason why, during the last several years, we made many field trips to study and collect some of the indigenous mycobiota of Argentina (Wright & Albert&pacute;, 2002, Wright & Albertó 2006).
The cultivation of Agaricus pseudoargentinus Albertó & Wright
Several years ago, we collected and named a new species of Agaricus (A. pseudoargentinus, Albertó & Wright 1994). In order to obtain fruitbodies of wild edible mushrooms of the genus Agaricus, six naturally occurring species from the environs of Buenos Aires (Argentina), A. bisporus, A. campestris, A. fiardii, A. nivescens, A. pampeanus, and A. pseudoargentinus were cultured under growing conditions similar to those required by A. bisporus. All strains grew well on sterile wheat grains, allowing optimum spawn production (Albertó 1997). Colonization of compost took between 11 and 18 days after spawning. Only A. bisporus and A. pseudoargentinus produced fruit bodies. A. pseudoargentinus produced pin-heads after 42 days of casing and developed fruitbodies at 18 C but with low yield (Fig. 1), reaching 230g/10 kg of compost (Albertó 1995).
Fig. 1. Production of Agaricus pseudoargentinus on compost used to cultivate A. bisporus.
The cultivation of Lentinus tigrinus (Bull.) Fr
Lentinus tigrinus was originally described as Pleurotus lindquistii by Singer (1960) as growing on trunks of Salix humboldtiana in the marginal rain forest of Río de la Plata (Buenos Aires). It was transferred to the genus Lentinus by Lechner & Albertó (2000). Lentinus tigrinus is a species with a fleshy pileus, strong odor and agreeable taste. In order to determine the optimal conditions for the production of this species, three substrates based on Salix sp. sawdust, wheat straw and supplements were tested in 500 g dry weight bags at two different fruiting temperatures. Naturally occurring strains of this species were incubated at 30 C. Primordium initiation could be observed 11 to 16 days after induction conditions began. This species produced highest yields with biological efficiency (BE) of 62% with supplemented sawdust at 25 C. When substrate in bags was reduced to 100 g dry weight, spawning run time was reduced from 28 to 30 days to 10 to 14 days and BE increased to more than 100% (Lechner & Albertó 2007).
The cultivation of Polyporus tenuiculus (P. Beauv.) Fr.
Polyoporus tenuiculus is a naturally occurring species from Central and South America (Borgues & Wright 2002) that is consumed by different ethnic groups in the region. To determine the optimal conditions for fruiting body production, two strains were assayed on wheat straw and sawdust with and without supplements. Incubation (60 d) at 25 C was needed to produce a solid block. The highest yield was obtained with supplemented willow sawdust. In a second experiment, different supplements were used to improve BE and to determine quality traits and biodegradation capacity. Highest yields were obtained on sawdust with 25% supplement reaching 83% BE. P. tenuiculus showed a capacity to degrade sawdust, causing a decrease of 67-75% cellulose, 80-86% hemicellulose and 61-66% lignin content at the end of the cultivation cycle (Omarini et al. 2009). This species can also be produced on logs (Fig. 2) using wood of Populus sp. and Eucalyptus sp. (Albertó & Omarini 2012). This is a promising species both for commercial production and for its potential use in the degradation of other biowastes. A sensory analysis also was made and compared with P. ostreatus (Omarini et al. 2010a). Also, volatile composition and nutritional quality of this species grown on different agro industrial waste was determined (Omarini et al. 2010b).
Fig. 2. Production of Polyporus tenuiculus on logs.
The cultivation of Pleurotus albidus (Berk.) Pegler
Pleurotus ostreatus has been commercially cultivated in Argentina for about 30 years. The majority of farmers use wheat straw as a substrate that is pasteurized by steam or hot water (Jaramillo & Albertó 2013).
In Argentina there are, so far, six species of Pleurotus, namely P. albidus, P. cystidiosus, P. ostreatus, P. pulmonarius, P. rickii and P. djamor, the latter with three varieties: var. djamor, var. cyathiformis and var. roseus (Lechner et al. 2004, Lechner et al. 2005). Yield values and morphological variations of fruitbodies obtained from the cultivation of fourteen Pleurotus strains isolated from naturally occurring specimens from Argentina were evaluated on supplemented Salix sawdust, wheat straw (W) and supplemented wheat straw (SW). The species studied were Pleurotus albidus, P. cystidiosus, P. djamor, P. ostreatus and P. pulmonarius. In general, wild strains had a reasonable performance on W or SW. The highest yield was obtained with P. albidus on wheat straw with a BE of 171% compared to 82% BE obtained for the commercial strain of P. ostreatus in the same substrate. It was also possible to find a strain of P. ostreatus with better BE than the commercial strain evaluated. Because of the high yields and the good quality of mushrooms obtained, we proposed P. albidus as a new species for intensive industrial cultivation (Lechner & Albertó 2011). This species, characterized by the white, circular to infundibuliform pileus with a margin entire to lacerate-crenate (Albertó et al. 2002) requires culture conditions similar to those of P. ostreatus. It will allow farmers to cultivate it without new requirements or larger investments allowing for expansion of the variety of products available to consumers.
Improvement of yields of Agrocybe cylindracea (Brig.) Singer
Agrocybe cylindracea is an excellent edible mushroom appreciated for its culinary properties and pleasant odor. This mushroom is known worldwide as A. aegerita, although we use the name A. cylindracea because this is the correct name (Uhart & Albertó 2007). We made a evaluation of genotypes and substrates to select the most productive strains. Commercial and naturally occurring A. cylindracea strains (12) from different continents were cultivated on wheat straw in order to compare their BE. Those strains that achieved highest yields were tested with different supplements. The Asiatic naturally occurring strain cultivated with soybean flour as a supplement achieved an average BE of 179% (Fig. 3), to our knowledge the highest reported for this species (Uhart et al. 2008).
Naturally occurring species could be a very important and large source of "new" germplasm to be cultivated worldwide. Providing high quality, functional food with fungal proteins would be distinct advantage for consumers.
Many naturally occurring strains could offer adaptive advantages to be locally produced, such as disease resistance or capacity to be cultivated in extreme conditions of temperature and humidity. Therefore, we propose the study of naturally occurring species as a useful practice to improve yields, to introduce new species to markets and to serve as a back-up for commercial germplasm of fungal species.
Fig. 3. Production of Agrocybe cylindracea on supplemented wheat straw.
Albertó E, Petersen RH, Hughes KW, Lechner BE (2002) Miscellaneous notes on Pleurotus. Persoonia 18:55-69.
Albertó E (1997) Spawn production in naturally occurring species of Agaricus from Argentina. Micol. Neptrop. Apl. 10: 1-13.
Albertó E, Wright JE (1994) Agaricus pseudoargentinus n. sp. from Argentina. Mycotaxon 50: 271-278.
Albertó E (1995) Studies on fruitbody production of naturally occurring species of Agaricus in A.bisporus compost. Indian J. Mycol. Pl. Pathol 25(3): 266-269.
Albertó E, Omarini A (2012) Adaptación al cultivo intensivo del hongo silvestre Polyporus tenuiculus (Basidiomycetes, Polyporales) en sustratos formulados y en troncos, en Sánchez JE & Mata G. (Editores) en "Hongos Comestibles y Medicinales en Iberoamérica: Investigaci&pacute;n y Desarrollo en un Entorno Multicultural". El Colegio de La Frontera Sur, Ecosur, Tapachula, México. 5(5.6): 255-268.
Borges da Silveira R, Wright JE (2002) Polyporus s. str. in southern South America: mating tests. Mycol. Res. 106 (11): 1323-1330.
Jaramillo S, Albertó E (2013) Heat treatment of wheat straw by immersion in hot water decreases mushroom yield in Pleurotus ostreatus. Rev. Iberoam. Micol. 30(2): 125-129.
Lechner B, Albertó E (2000) Pleurotus lindquistii is a Lentinus. Mycotaxon: 76: 97-104.
Lechner BE, Wright JE, Albertó E (2004) The genus Pleurotus in Argentina. Mycologia 96:845-858.
Lechner BE, Wright JE, Albertó E (2005) The genus Pleurotus in Argentina: mating tests. Sydowia 57:233-245.
Lechner BE, Albertó E (2007) Optimal conditions for the fruitbody production of naturally occurring strains of Lentinus tigrinus. Bioresource Technology 98: 1866-1869.
Lechner B, Albertó E (2011) Search for new naturally occurring strains of Pleurotus to improve yields. P. albidus as a novel proposed species for mushroom production. Rev Iberoam Micol: 28(4): 148-154.
Omarini A, Lechner BE, Albertó E (2009) Polyporus tenuiculus: a new naturally occurring mushroom that can be industrially cultivated on agricultural waste. Journal of Industrial Microbiology & Biotechnology 36: 635-642.
Omarini A, Nepote V, Grosso N, Zygadlo J, Albertó E (2010a) Analysis and fruiting bodies characterization of the edible mushrooms Pleurotus ostreatus and Polyporus tenuiculus obtained on leaf waste from the essential oil production industry. International Journal of Food Science and Technology: 45: 466-474.
Omarini A, Henning C, Ringuelet J, Zygadlo JA, Alberto E (2010b) Volatile composition and nutritional quality of the edible -mushroom Polyporus tenuiculus grown on different agro-industrial waste. International Journal of Food Science and Technology: 45: 1603-1609.
Singer R (1960) Dos especies interesantes de Agaricales en Punta Lara. Bol. Soc. Arg. Bot. 8(3-4): 216-218.
Uhart M, Albertó E (2007) Morphologic characterization of Agrocybe cylindracea (Basidiomycetes, Agaricales) from America, Europe and Asia. Revista Mexicana de Micología 24: 9-18.
Uhart M, Piscera JM, Albertó E (2008) Utilization of new naturally occurring strains and supplementation to improve the biological efficiency of the edible mushroom Agrocybe cylindracea Journal of Industrial Microbiology and Biotechnology 35(6):595-602.
Wright JE, Albertó E (2002) Guía de hongos de la región pampeana. I. Hongos con laminillas. Literature of Latin America (Lola). Buenos Aires 278p.
Wright JE, Albertó E (2006) Guía de hongos de la región pampeana. II. Hongos sin laminillas. Literature of Latin America (Lola). Buenos Aires. 410p.
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Dr. Manjit Singh
Directorate of Mushroom Research
Solan (HP), India
Message from Dr. Manjit Singh, Chairman, 8 thInternational Conference on Mushroom Biology and Mushroom Products (WSMBMP), 19-22 Nov, 2014, New Delhi, India
WSMBMP has played a proactive role in enhancement and application of knowledge related to basic and applied aspects of mushroom biology and mushroom products for many years. One aspect of WSMBMP role is to provide a platform for knowledge sharing and interaction among all stakeholders by organizing international conferences at regular intervals.
We are pleased to announce that the 8th International Conference on Mushroom Biology and Mushroom Products will be held in New Delhi from 19-22 November 2014. The meeting is being organized in collaboration with the Directorate of Mushroom Research, Solan and the Mushroom Society of India. A website for the conference (www.icmbmp8.org) was placed in operation on 15th January 2014. The important dates for participation in the conference are as follows:
We encourage participants to register for the conference at your earliest convenience. Active participation and support is vital for success of the event and to ensure continuous growth of mushroom science and the mushroom industry.
We look forward to welcoming you in New Delhi in November.
Dr. Manjit Singh
Directorate of Mushroom Research
Solan (HP), India
| Registration starts on|| January 15, 2014|
| Call for abstracts opens ||January 25, 2014
| Call for abstracts closes || July 1, 2014
| Notification to authors || July 31, 2014
| Last date for full papers || September 15, 2014
| Early bird registration fee by || July 31, 2014
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The WSMBMP Bulletin is the official electronic publication of the World Society for Mushroom Biology and Mushroom Products. The bulletin is intended to keep members informed about Council activities and to share general information about mushrooms. It is designed to allow communication between society members and alert them about new topics and opportunities related to mushrooms. Society members and general public are kindly invited to submit letters, comments and information of interest for the mushroom community to be published in the bulletin. Please submit your contributions electronically in free format to the editors JosÃ© E. Sanchez firstname.lastname@example.org, John Buswelljabuswell2003@yahoo.co.uk, Daniel J. Royse email@example.com or Helen Grogan firstname.lastname@example.org.
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