Ecology and Distribution of Desert Truffles in Algeria

The distribution and abundance of the various truffle species are influenced by the climate, soil, and vegetation conditions. The setting of these characteristics is necessary for the potential species’ cultivation. Here, we describe the ecological characteristics of Moroccan truffles and desert truffles and their associations with host plants. We also determine the climate and soil parameters relating to the geographic distribution and fructification of truffles and desert truffles. In contrast to truffles, which are found in sub-humid environments, desert truffles are found in semi-arid and arid regions of Morocco. The dissemination of desert truffles in the Mamora forest and oriental regions of Morocco is typically linked to the presence of Helianthemum sp., whereas the existence of truffles (Tuber spp.) in the Middle Atlas depends on the subsistence of Quercus ilex and Q. faginea. The truffles’ and desert truffles’ fructification depends mainly on the precipitation frequency. Terfezia arenaria and Tuber oligospermum, the two major desert truffles of Mamora forest, require an annual rainfall of 435 mm on average in slightly acidic soil. While the oriental and Highland desert truffles, namely Terfezia boudieri, T. claveryi, and Tirmania spp., require an annual precipitation average of 123 to 267 mm and a high CaCO3 content. Otherwise, there is Tuber aestivum, localized in humid regions with a rainfall rate of more than 650 mm, and found under calcareous soil rich in organic matter with the presence of potential host plants, such as oaks, cedars, and pines. Our findings open up the possibility of successful cultivation of truffles and desert truffles having an economic interest through understanding their ecological requirements in Morocco.

This chapter summarizes the latest basic and applied advances in desert truffle research carried out to improve our knowledge of the biodiversity, physiology, biotechnology, and cultivation of these hypogeous and edible fungi. ITS-rDNA sequences in phylo-geographic studies and host plant and soil pH characteristics have been the key to describing eight new desert truffle species. The production of desert truffle mycorrhizal plants has been improved by using β-cyclodextrin and bioreactors for mycelium culture and native beneficial bacteria (PGPR and MHB) to increase seedling survival and mycorrhization. Some fungal enzymes have also been characterized in Terfezia claveryi ascocarps. The presence of alkaline phosphatase both in mycelia and ascocarps indicates that this enzyme plays an important role during the life cycle of T. claveryi, while acid phosphatase might be involved in a process that takes place during the ascocarp stage. Numerous desert truffle plantations have been established in Spain in the last 10 years. A high density of mycorrhizal plants combined with a proper irrigation are two important factors to stimulate ascocarp production. The combination of a high rate of intracellular colonization together with the fine-tuned expression of fungal and plant aquaporins could result in a morpho-physiological adaptation of this symbiosis in drought conditions. Moreover, desert truffle sylviculture is proposed for improving truffle production and for conserving the natural areas where desert truffle grow.

The first evidence of the use of desert truffles (hypogeous Ascomycetes), which have nourished populations in the world’s arid and semiarid areas throughout history, is found among the oldest records of human culture. Desert truffles were coveted by the Bronze Age Amorites, mentioned in the Bible, and discussed by the Classic Greeks, Romans, and in the Jewish Talmud. Islam’s Prophet Muhammad recommended their medicinal use. The vernacular terms for desert truffles have changed little through the millennia, suggesting a common desert truffle culture. Travelers throughout history have recorded the culinary, medicinal, and artistic uses of desert truffles among the local communities they passed through, observing that desert truffles have often been a survival food for these communities. The desert truffles with the longest record of use are the species of Tirmania and Terfezia. The people with the longest recorded use of desert truffles are the Bedouins. The Khoisan of the Kalahari and the Aborigines of Australia have also had a long, yet mostly unrecorded, history of desert truffle use. These three different cultures show similarities in their cooking techniques and medicinal uses of desert truffles. Efforts to cultivate them in their growing habitats may slow down the demise of desert truffles in the wild, offer local economic incentives, and protect the desert truffle culture among indigenous peoples. This chapter will attempt to offer a glimpse into the long and rich history of the use of desert truffles among the different populations that have gathered them and depended on them throughout history.

Throughout human history, desert truffles have been used for their nutrition, as functional foods for health promotion and disease prevention, and as treatments for a variety of diseases, particularly eye diseases and skin lesions. Many of the details of this long history have been lost through time, due to the largely oral traditions of the populations that have used desert truffles. Nonetheless, valuable information about the medicinal uses of desert truffles has survived through the traditional medicines that are still practiced in the Middle East, North Africa and the Sahara, the African Kalahari, and the Australian Outback. The use of desert truffles in traditional medicine has led to modern scientific investigation into their bioactive properties. This research has revealed that desert truffles are nutritious and contain multiple antioxidants and has demonstrated that desert truffle extracts have antimicrobial properties that are effective against common pathogens that cause disease in humans. The research reviewed in this chapter suggests that desert truffles may potentially represent an untapped source of novel pharmaceuticals that could treat a wide variety of modern-day ailments.

Comparative metabolome classification of desert truffles Terfezia claveryi and Terfezia boudieri via its aroma and nutrients profile

Desert truffles have traditionally been used as food in Libya. Desert truffle grows and gives fruit sporadically when adequate and properly distributed rainfall occurs with existence of suitable soil and mycorrhizal host plant. The present study aimed to identify and characterize two kinds of wild desert truffles from ecological and nutritional points that were collected from the studied area. The truffle samples were identified as Terfezia (known as red or black truffle) and Tirmania (known as white truffle). The nutritional values (protein, lipid and carbohydrate) of both Libyan wild truffle (Terfezia and Tirmania) were determined on a dry weight basis and result showed that Tirmania and Terfezia contained 16.3 and 18.5% protein, 6.2 and 5.9% lipid, 67.2 and 65% carbohydrate, respectively, in ascocarp biomass. The soil pH of the upper and lower regions of the Hamada Al-Hamra ranged between 8.2 and 8.5 giving suitable conditions for fructification. The plants, Helianthemum kahiricum and Helianthemum lippii were the dominant plants in Hamada Al-Hamra region found to form a mycorrhiza with desert truffles. The phylogenetic analysis of the genomic rDNA ITS region showed that, out of five collections three represented Tirmania pinoyi (Maire) Malencon, one Tirmania nivea (Desf.) Trappe, and one Terfezia boudieri Chatin.

Detection of Tirmania pinoyi in Roots of Inoculated Cistaceae Plant Species by Nested Polymerase Chain Reaction

For several years, greater attention has been focused on desert truffles of Southern and Western Algeria.The present work is the first to be concerned on desert truffles from northeastern Algerian littoral dunes.The aim of this work is to describe northeastern Algerian truffle fields, identify collected truffle species and their symbiotic plant partner.We required two years field prospections, soil analysis, ascocarps morpho-anatomical and molecular analysis.We concluded that truffle fields share an acid sandy-loam soil and a notable abundance of many subspecies of Tuberaria gutatta (L.) Fourr.1868, proved as desert truffles symbiotic partner.Two sandy truffle species are recorded: Terfezia arenaria (Moris) Trappe (1971) and Tuber gennadii (Chatin) Patouillard 1903.This data is the first to review knowledge on northeastern desert truffles and to report Tuber gennadii in Algeria.

Desert truffle is becoming a new crop in semiarid areas. Climatic parameters and the presence of microorganisms influence the host plant physiology and alter desert truffle production. Desert truffle plants present a typical summer deciduous plant phenology divided into four stages: summer dormancy, autumn bud break, winter photosynthetic activity, and spring fruiting. We hypothesize that the bacterial community associated with desert truffle plants will show a seasonal trend linked to their plant growth–promoting rhizobacteria (PGPR) traits. This information will provide us with a better understanding about its potential role in this symbiosis and possible management implementations. Bacteria were isolated from root-adhering soil at the four described seasons. A total of 417 isolated bacteria were phenotypically and biochemically characterized and gathered by molecular analysis into 68 operational taxonomic units (OTUs). They were further characterized for PGPR traits such as indole acetic acid production, siderophore production, calcium phosphate solubilization, and ACCD (1-amino-cyclopropane-1-carboxilatedeaminase) activity. These PGPR traits were used to infer functional PGPR diversity and cultivable bacterial OTU composition at different phenological moments. The different seasons induced shifts in the OTU composition linked to their PGPR traits. Summer was the phenological stage with the lowest microbial diversity and PGPR functions, whereas spring was the most active one. Among the PGPR traits analyzed, P-solubilizing rhizobacteria were harbored in the mycorrhizosphere during desert truffle fruiting in spring.

SummaryDesert truffles are edible hypogeous fungi forming ectendomycorrhizal symbiosis with plants of Cistaceae family. Knowledge about the reproductive modes of these fungi and the molecular mechanisms driving the ectendomycorrhizal interaction is lacking.Genomes of the highly appreciated edible desert truffles Terfezia claveryi Chatin and Tirmania nivea Trappe have been sequenced and compared with other Pezizomycetes. Transcriptomes of T. claveryi × Helianthemum almeriense mycorrhiza from well‐watered and drought‐stressed plants, when intracellular colonizations is promoted, were investigated.We have identified the fungal genes related to sexual reproduction in desert truffles and desert‐truffles‐specific genomic and secretomic features with respect to other Pezizomycetes, such as the expansion of a large set of gene families with unknown Pfam domains and a number of species or desert‐truffle‐specific small secreted proteins differentially regulated in symbiosis. A core set of plant genes, including carbohydrate, lipid‐metabolism, and defence‐related genes, differentially expressed in mycorrhiza under both conditions was found.Our results highlight the singularities of desert truffles with respect to other mycorrhizal fungi while providing a first glimpse on plant and fungal determinants involved in ecto to endo symbiotic switch that occurs in desert truffle under dry conditions.

Desert truffles have become an alternative agricultural crop in semiarid areas of the Iberian Peninsula due to their much appreciated edible value and their low water requirements for cultivation. Although most studies related to desert truffle production point to the sole importance of precipitation, this work is the first systematic study carried out to characterize whether other important agroclimatic parameters, for example reference evapotranspiration, soil water potential, relative air humidity %, aridity index or air vapour pressure deficit, may have an impact on a desert truffle production in an orchard with mycorrhizal plants of Helianthemum almeriense × Terfezia claveryi for 15 years from the plantation. The results show for the first time that T. claveryi production has two key periods, during its annual cycle: autumn (September to October) and spring (end of March). The aridity index and soil water potential seem to be the most manageable parameters in the field and can be easily controlled by applying irrigation during the abovementioned periods. Agroclimatic parameters can influence the final crop a long time before the desert truffle fruiting season contrary to what happens with other edible mycorrhizal mushrooms. Four different models to manage desert truffle plantations are proposed based on these agroclimatic parameters in order to optimize and stabilize carpophore fructifications over the years.

This chapter undertakes to sum up information concerning desert truffles in non-Mediterranean Asian countries. Included are Iran, Pakistan, Azerbaijan, Arab Peninsula, and China. Desert truffles and semiarid truffles are collected from the wild in appropriate habitats, which are described. In some places mountain ranges have the climate and soil conditions suitable for desert truffles. In others—the right conditions are found in steppes. Different species of desert truffles are described from different areas. These truffles form symbiotic associations with plant species such as grasses (bog sedge), crop species (sorghum and maize), shrubs (Helianthemum spp.), or trees (e.g., pine). Truffling season varies between spring in the Arab Peninsula and autumn in China. In some countries such as Saudi Arabia, desert truffles are considered a delicacy from ancient times till today; in others such as Pakistan and China, they are virtually unknown or not appreciated. Truffle species encountered in the various countries include Terfezia boudieri, T. claveryi, T. aphroditis, T. hanotauxii, T. hafizi, T. leonis (=Terfezia arenaria), T. transcaucasica, T. parvocarpus, Tirmania pinoyi, Mattirolomyces terfezioides, Picoa lefebvrei, and Leucangium carthusianum (=Picoa carthusiana).KeywordsFruit BodySaudi ArabiaArab PeninsulaAutonomous RepublicDesert TruffleThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Desert truffles are an obligate hypogenous ectomycorrhizal fungi in association with host plant roots Helianthemum sp. and are of socioeconomically important and naturally grown in the Middle East, North Africa, Southern Europe, Mediterranean countries including Arab Gulf countries. Truffles are edible and a rich source of protein and various chemical compounds and traditionally have been used as folk medicine in the Arabian countries. The last decade has witnessed an increase research interest focused on the biosynthesis of metal nanoparticles using fungi as natural sources and as a good tool in nanobiotechnology. Nevertheless, recently metal nanoparticles have been widely applied in multidisciplinary fields including medical and pharmaceutical applications. Among nanometals, silver nanoparticles are of great significance to be used in pharmaceutical aspect as antimicrobial agent. According to our knowledge little information so far is available regarding biosynthesis of silver nanoparticles by the truffles and to search for new antimicrobial alternatives, therefore, the objective of this study was to explore the desert truffle (Tirmania nivea) for its potentiality to biosynthesize silver nanoparticles (AgNPs) and to examine their efficacy against five strains of human pathogenic bacteria namely; Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus. Fruiting bodies (Ascocarps) of the truffle T. nivea were collected from the sandy desert of Iraq and brought to the laboratory, washed thoroughly with distilled water and dried at room temperature. Twenty gram of dried fruit bodies of truffle were grounded and dissolved in boiled water and filtered using Whatman filter paper No 1. For synthesis process of silver nanoparticles, 100 mL of truffle extract filtrate was treated with 1 mM of AgNO3 solution and kept for 24 hr at dark condition and synthesis of silver nanoparticles (AgNPs) was checked by visual observation of color changes from pale yellow to dark brown and was further confirmed by UV – Vis spectrum. Fungal filtrate without AgNO3 was maintained as control. The potentiality of silver nanoparticles was examined for their antibacterial efficiency using agar well diffusion method against the selected strains of pathogenic bacteria. Wells (5 mm diam) were made in Muller-Hinton agar (MHA) plates streaked with swabs of each bacterial strain. The wells were loaded with two concentrations (50 and 100 ul) of synthesized silver nanoparticles solutions. Incubated at 37°C for 24 hr and examined for the appearance of inhibition zones around the wells and their diameters were measured. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) assay was carried out using the micro dilution method with serial dilutions (100, 50, 25, 12, 6.5, 3.13, 1.56, 0.78, 0.39, 0.2, 0.1, 0.05, 0.025 μg/L) of the truffle extract filtrate against two strains of bacteria E. coli (ATCC 25922) and S. aureus (NCTC 6571). Disc diffusion method was used to assay the synergistic effect of synthesized AgNPs with commonly used antibiotic Gentamycin. Cytotoxicity of the truffle extract was examined against human blood. Characterization of the biosynthesized silver nanoparticles from truffle extract was carried out by using UV-Vis spectrophotometer analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The results showed that the biosynthesized silver nanoparticles exhibited a high growth inhibition activity at 50 ul/ml concentration (12–25.5 mm inhibition zones dim) and at 100 ul/ml (14.5–28 mm inhibition zones diam) against the tested pathogenic bacterial strains. Among the tested bacteria, highest growth inhibition was noticed against P. aeruginosa (25.5 and 228 mm diam) at the two concentrations of AgNPs, respectively. However, a remarkable increase of bacterial growth inhibition zones (23–37 mm diam) was observed for a combination of silver nanoparticles and Gentamycin compared with Gentamycin alone (20–30 mm diam). MIC values were very low (0.312 and 0.0097 ug/ml) against the two tested bacterial strains E. coli and S. aureus, respectively. The truffle extract did not show any toxicity against human blood. UV-Vis spectrophotometer analysis revealed a peak at 420 nm indicating the biosynthesis of silver nanoparticles, FTIR analysis verified the detection of protein capping of biosynthesized AgNPs while SEM images showed that the synthesized silver nanoparticles are dispersed or aggregated and mostly spherical shape and their size ranging between 3–41 nm. It can be concluded that the biosynthesized silver nanoparticles by the desert truffle T. nivea are a promising for future medical and pharmaceutical applications as antibacterial agent and a further investigation to examine their efficacy in vivo is recommended.

Desert truffles are edible hypogenous fungi that are very well adapted to conditions of aridity in arid and semi-arid regions. This study aims to highlight the influence of climatic factors on the productivity of desert truffles under hyper-arid climatic conditions of the Sahara Desert in Algeria, with assumptions that the more varying climatic factors, mainly rainfall, are more crucial for the development and production of desert truffles. At seven separate sites, desert truffles were collected by systematic sampling between 2006 and 2012. The effects of climate parameters of each site on the productivities (g/ha/year) of desert truffle species were tested using generalized linear models (GLMs). The annual mean of the total production recorded for all three harvested species (Terfezia arenaria, Terfezia claveryi, and Tirmania nivea) was 785.43 ± 743.39 g/ha. Tirmania nivea was commonly present over the sampled sites with an occurrence of 70 ± 10.1%. GLMs revealed that total and specific productivities were closely positively related to autumnal precipitations occurring during October-December, which is the critical pre-breeding period for both desert truffles and host plant species. The other climatic parameters have statistically no effect on the annual variation of desert truffle productivity.

Desert truffles are an obligate hypogenous ectomycorrhizal fungi in association with host plant roots Helianthemum sp. and are of socioeconomically important and naturally grown in the Middle East, North Africa, Southern Europe, Mediterranean countries including Arab Gulf countries. Truffles are edible and a rich source of protein and various chemical compounds and traditionally have been used as folk medicine in the Arabian countries. The last decade has witnessed an increase research interest focused on the biosynthesis of metal nanoparticles using fungi as natural sources and as a good tool in nanobiotechnology. Nevertheless, recently metal nanoparticles have been widely applied in multidisciplinary fields including medical and pharmaceutical applications. Among nanometals, silver nanoparticles are of great significance to be used in pharmaceutical aspect as antimicrobial agent. According to our knowledge little information so far is available regarding biosynthesis of silver nanoparticles by the truffles and to search for new antimicrobial alternatives, therefore, the objective of this study was to explore the desert truffle (Tirmania nivea) for its potentiality to biosynthesize silver nanoparticles (AgNPs) and to examine their efficacy against five strains of human pathogenic bacteria namely; Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus. Fruiting bodies (Ascocarps) of the truffle T. nivea were collected from the sandy desert of Iraq and brought to the laboratory, washed thoroughly with distilled water and dried at room temperature. Twenty gram of dried fruit bodies of truffle were grounded and dissolved in boiled water and filtered using Whatman filter paper No 1. For synthesis process of silver nanoparticles, 100 mL of truffle extract filtrate was treated with 1 mM of AgNO3 solution and kept for 24 hr at dark condition and synthesis of silver nanoparticles (AgNPs) was checked by visual observation of color changes from pale yellow to dark brown and was further confirmed by UV – Vis spectrum. Fungal filtrate without AgNO3 was maintained as control. The potentiality of silver nanoparticles was examined for their antibacterial efficiency using agar well diffusion method against the selected strains of pathogenic bacteria. Wells (5 mm diam) were made in Muller-Hinton agar (MHA) plates streaked with swabs of each bacterial strain. The wells were loaded with two concentrations (50 and 100 μl) of synthesized silver nanoparticles solutions, incubated at 37 °C for 24 hr and examined for the appearance of inhibition zones around the wells and their diameters were measured. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) assay was carried out using the micro dilution method with serial dilutions (100, 50, 25, 12, 6.5, 3.13, 1.56, 0.78, 0.39, 0.2, 0.1, 0.05, 0.025 μg/L) of the truffle extract filtrate against two strains of bacteria E. coli (ATCC 25922) and S. aureus (NCTC 6571). Disc diffusion method was used to assay the synergistic effect of synthesized AgNPs with commonly used antibiotic Gentamycin. Cytotoxicity of the truffle extract was examined against human blood. Characterization of the biosynthesized silver nanoparticles from truffle extract was carried out by using UV-Vis spectrophotometer analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The results showed that the biosynthesized silver nanoparticles exhibited a high growth inhibition activity at 50 μl/ml concentration (12–25.5 mm inhibition zones dim) and at 100 μl/ml (14.5–28 mm inhibition zones diam) against the tested pathogenic bacterial strains. Among the tested bacteria, highest growth inhibition was noticed against P. aeruginosa (25.5 and 228 mm diam) at the two concentrations of AgNPs, respectively. However, a remarkable increase of bacterial growth inhibition zones (23–37 mm diam) was observed for a combination of silver nanoparticles and Gentamycin compared with Gentamycin alone (20–30 mm diam). MIC values were very low (0.312 and 0.0097 μg/ml) against the two tested bacterial strains E. coli and S. aureus, respectively. The truffle extract did not show any toxicity against human blood. UV-Vis spectrophotometer analysis revealed a peak at 420 nm indicating the biosynthesis of silver nanoparticles, FTIR analysis verified the detection of protein capping of biosynthesized AgNPs while SEM images showed that the synthesized silver nanoparticles are dispersed or aggregated and mostly spherical shape and their size ranging between 3–41 nm. It can be concluded that the biosynthesized silver nanoparticles by the desert truffle T. nivea are a promising for future medical and pharmaceutical applications as antibacterial agent and a further investigation to examine their efficacy in vivo is recommended.