ABSTRACT
The mycobiota of the sandy soil of Egyptian beaches was investigated in thirty six sand samples collected from nine different localities in Egypt. The filamentous fungi were identified and assigned to thirty one genera and fifty one species. Greater populations as well as a wider spectrum range of fungal genera and species were obtained in sandy soil of Alexandria beach while Balteem beach was the poorest one. The total count of the genus or species did not always follow the number of cases of isolation. Most of the genera detected belonged to the Deuteromycotina with fewer proportions belonging to the Ascomycotina and Zygomycotina. The genera of highest incidence and their respective numbers of species were: Penicillium (35.72%, 6 spp.) and Aspergillus (30.28%, 16 spp.). The species which showed the highest incidence in all cases was P. chrysogenum, followed by P. citrinum, A. flavus, Chaetomium murorum and Trichoderma viride. Several other genera and species were detected at quite low occurrence.
PDF Abstract XML References Citation
How to cite this article
DOI: 10.3923/pjbs.2003.860.866
URL: https://scialert.net/abstract/?doi=pjbs.2003.860.866
INTRODUCTION
Fungi are distributed throughout nature and dispersion persists the species to be in equilibrium with one another and with other organisms in their habitats. Many fungi can be isolated from the air, with their incidence varying according to geographic, environmental or bioclimatic factors such as collection site, time of the years relative air humidity, rainfall, wind speed and proximity to the source where they were produced (Gambale et al., 1983, Meyer et al., 1983, Oliveira et al., 1993, Tan et al., 1992). Consequently, these factors determine the quality and quantity of the mycobiota existing in aquatic and terrestrial ecosystems. Kohlmeyer and Kohlmeyer (1971) and Tan (1985), among others, recorded exclusively marine fungi, but the soil is the typical reservoir of anemophilous fungi (Hawksworth, 1991).
Studies carried out at the interface of marine and terrestrial ecosystems by Bergen and Wagner-Merner (1977), Dabrowa et al. (1964), Kishimoto and Baker (1969) and Ristanovic and Miller (1969) refer almost exclusively to fungi representing the soil community, perhaps because this is the most numerous and is favored by greater facility of formation, survival and dispersal of the light propagula of its representative. Beach sand, where fungal conidia are viable under certain specific conditions, can play an important role as a vehicle in the transmission of the infectious processes (Larrondo and Calvo, 1989).
An evaluation of the mycological quality of the sand beaches of the Lisbaa and Vale do Tejo coastal area in Portungal was under taken in May-October, 1964. The Keratinolytic fungi, yeasts, potential pathogenic and allergic and/or environmental saprophytic fungi were analyzed. The data showed good/satisfactory quality of the sand beaches for the genus Candida. The results indicated that the allergic and/or environmental saprophytic fungi were the most common in sand beaches. It is suggested that Scopulariopsis and Candida could be used as specific indicator organisms of sand beaches quality. A new quality objective is introduced that will contribute to improving sand beaches quality (Mendes et al., 1998). Mendes et al., (1993) reported that beach sand showed a higher level of microbiological contamination than sea water. The level of contamination may be related to direct or indirect microbial contamination from beach users. The level preliminary criteria for beach sand microbiological quality were developed on the basis of public health considerations.
The predominance of subdivisions: Deuteromycotina, Ascomycotina and Zygomycotina has been observed in coastal soils of California by Dabrowa et al. (1964), in coastal soils of Florida by Bergen and Wagner-Merner (1977) and in coastal soils of Hawaii by Kishimoto and Baker (1969). In studies carried out on the water and sand of the Boa Viagem beach, Becife, Brazil, Pinto et al. (1992) detected 115 species while Sarquis and Oliveira (1996) isolated 170 species from sandy soil of Ipanema beach. These results showed a much higher species diversity than reported by Moustafa and Al-Musallam (1975) in Kuwait and Bergen and Wagner-Merner (1977) in the U.S.A. These variations may probably be attributed to bioclimatic factors acting on and/or interfering with, fungal survival and dispersal. It is also possible that the frequency of bathers who carry propagula and leave substance, might create conditions favourable to fungal development, as suggested by Bergen and Wagner-Merner (1977).
The aim of this study is to determine the presence and density of viable fungal conidia in samples of sands obtained from different localities of Egyptian beaches.
MATERIALS AND METHODS
Following the method described by Johnson et al. (1959), thirty-six soil samples were collected from the sand beaches of different localities in Egypt. These localities include: Alexandria, Balteem, Gamsah, Ras El-Bar, Port-Said, Ismailia, Suez, Hargadah and South Sinai.
The soil samples were analyzed chemically for the estimation of total soluble salts, organic matter, chloride, electric conductivity and pH value. The dilution plate method was used for the estimation of soil fungi, as described by Johnson et al. (1959) but with some modifications. One of these is the use of Menzies (1957) dipper to replace pipettes. Modified Gzapek's medium in which glucose (10 gm L-1) replaces sucrose and rose Bengal was added as bacteriostatic agent to the medium at concentration of 1/15000 (Smith and Dawson, 1944) for determination of fungi.
Six plates were used for each sample. They were incubated at 25oC for isolation the fungi. The colonies of slow growing fungi which were about to be overgrown as well as mycelial fragments of some colonies were transferred to Czapek's agar + 0.05% yeast extract, or potato dextrose agar. The developing fungi were counted and identified.
RESULTS
Fifty one species belonging to thirty one genera were identified, in addition to the Mycelia sterilia (Table 1). The highest total count of fungi (C = 149.93 colonies/mg soil) was recorded in the samples collected from sandy soil of Alexandria beach, while the lowest total count (C = 44.85 colonies/mg soil) was recorded in the samples of Balteem beach.
Four genera, namely: Penicillium, Aspergillus, Chaetomium and Trichoderma, were represented in the sand beaches of the all nine localities but their counts and presence values in the collected samples of each locality varied.
Aspergillus showed the broadest spectrum range of the species and it represented by sixteen species, followed by Penicillium which represented by six species only. Their percentage counts were the highest (30.28% and 35.72% of the fungal total count respectively). In addition, Chaetomium (C. murorum) was represented by 10.93% while Trichoderma (T. viride) was represented by 8.05%.
Table 1: | Mean total count of each genus and species isolated from all localities investigated (calculated per mg soil) as well as frequency of occurrence |
Occurrence Remark: H = high > 18 cases out of 36 (>50%), M = Moderate, 9-18 cases out of 36 (25-50%); L = low, 4-8 cases out of 36 (12-25%); R = rare < 4 cases out of 36 (<12%) |
On the other hand, each of the rest of genera was represented by one species only and were occupied in 15.02% of the total count of fungi.
The fungi represented in (Table 1) showed that, the fungal species of high frequency of occurrence included: Aspergillus flavus, A. niger, A. sydowii, A. terreus, Cephalosporium curtipes, Chaetomium murorum, Penicillium chrysogenum, P. citrinum, Stachybotrys atra and Trichoderma viride were recorded in more than 18 cases out of thirty six. The results showed also that, Alternaria alternata, Aspergillus glaucus, A. janus, A. alutaceus, Botryotrichum piluliferum, Cladosporium herbarum, Penicillium corilophylum, P. brevicompactum and Verticillium sp. were of moderate occurrence. They were recorded in 9-18 cases out of 36.
The infrequent species of low occurrence, which were isolated from 4-9 cases out of 36; these species were: Aspergillus candidus, A. fumigatus, A. thomii, A. versicolor, A. wentii, Penicillium jenseni, P. purpurogenum, Scopulariopsis brevicaulis and Syncephalastrum racemosum. In addition, Aspergillus awamori, A. foetidus, A. sulphureus, A. ustus, Circinella simplex, Cunninghamella echinulata, Drechslera australiensis, Emericella nidulans, Epicoccum purpurascens, Fennellia flavipes, Fusarium moniliforme, Gliocladium roseum, Helminthosporium sp., Humicola grisea, Mucor racemosus, Nigrospora sphaerica, Phoma humicola, Scytalidium lignicola, Sepedonium chyrsospermum, Spicaria silvatica, Staphylotrichum coccosporum, Stemphylium solani and Thermomyces lanuginosus were of rare frequency of occurrence. Most of genera or species did not show regular correlation between the count and number of cases of isolation.
The results in (Table 2) showed that, the highest total counts were recorded in the soil samples collected from sand beaches of Alexandria followed by South Sina and Port Said (C = 149.9, 106.6 and 97.1 colonies per mg dry soil respectively). These samples were characterized by relative high organic matter content ranged between 0.2-0.4%, total soluble salts from 0.95% - 2.75%. On the other hand, sand beach of Balteem was appeared to be the poorest one in the total count of fungi. It was characterized by its poverty in organic matter content 0.18%, total water soluble salts (0.65%). pH values of the soil samples reveal no appreciable differences, all are alkaline and the pH ranges from 7.96 - 8.99.
The results represented in (Tables 2 and 3) showed also that, the highest number of genera and species were recorded in soil samples of sand beaches of Alexandria (19 G and 36 spp.), where Aspergillus (mainly A. flavus and A. niger) was the dominant genus, Ras El-Bar (19 G and 31 spp.), Penicillium showed the highest total count which contributed to P. chrysogenum and South Sina (16 G and 33 spp.), of which Aspergillus especially A. flavus was the most common. Samples collected from Hargadah and Ismailia show approximately the same number of genus and species (14G and 23 spp. and 13G and 22 spp. respectively) and also it was similar in case of Gamsah (8G and 18 spp.) and Suez (8G and 19 spp.).
DISCUSSION
The fungi isolated belong to fifty one species and thirty one genera (Table 1). Greater populations as well as a wider spectrum range of fungal genera or species were recorded in sandy soil of beach Alexandria and this was affected by organic matter content and the total water soluble salts. These results were in accordance with Sarquis and Oliveira (1996) and Bergen and Wagner-Merner (1977). The authors reported that these variations may probably be attributed to bioclimatic factors acting on and/or interfering with, fungal survival and dispersal. It is also possible that the frequency of bathers who carry propagula and leave substrates, might create conditions favourable to fungal development. The level of contamination may be related to direct or indirect microbial contamination from beach users (Mendes et al., 1996).
Genera Penicillium, Aspergillus, Trichoderma, Chaetomium, Stachybotrys and Cephalosporium were of high occurrence (frequency more than 50%), while Botryotrichum, Cladosporium and Verticillium showed moderate occurrence (frequency, 25-50%) and
Table 2: | Soil analysis of the different localities, pH value, electric conductivity (E.C.), organic matter content (O.M.C), total soluble salts (T.S.S.), chloride, water content (W.C.), total count of fungi (T.C.), number of genera (No.G.), number of species (No. spp.) |
Table 3: | Mean total count per mg soil (T.C.) and number cases of isolation (NCI) of fungi recorded in sand beaches of different localities. 1; Alexandria, 2; Balteem, 3; Gamsah, 4; Hargadah, 5; Ismailia, 6; Port-Said, 7; Ras-El Bar, 8, Suez and 9; South Sinai |
the other fungal genera showed low and rare occurrence (frequency, 12-25% and < 12% respectively). Penicillium and Aspergillus accounted for about 65.9% of the mean total count of fungi. Parallel to this result Mendes et al. (1998) showed that the environmental saprophytic fungi were the most common in the sand beaches of Portugal. Sarquis and Oliveira (1996) reported that the genera of highest incidence recorded in the sandy soil of Iponema beach were; Aspergillus, Penicillium, Fusarium and Trichoderma. Also, Jose et al. (1994) found that these genera were dominated in 2 sand beaches in Portugal. Moreover, Moubasher and Moustafa (1970), El Dohlob and Abu- Ellil (1978), El-Fallal (1982) and El-Dohlob et al. (1985) found that Aspergillus, Penicillium and Fusarium were frequent in Egyptian soil.
The genus Penicillium was isolated from all samples, independently of the area and it was the most abundant genus observed. The data are coincident with those reported by several authors who mention the constant presence of Penicillium in the mycoflora from different areas in the world (Calvo et al. 1980 a and b and De Almeida, 1997). The species of Penicillium genus detected were: P. chrysogenum, P. citrinum, P. corilophylum, P. jenseni, P. purpurogenum and P. brevicompactum. P. chrysogenum was the most frequent species (97.22%) while P. purpurogenum was the least frequent one. Many of the isolated species belonging to the genus Penicillium are part of the atmospheric mycoflora, as it reported in different studies (Larrondo and Calvo, 1989; Calvo et al., 1979; Gregory, 1973 and Guarro et al., 1981).
Aspergillus genus is the second in incidence, though its isolation varied in the different beach samples according to the area. Aspergillus genus has been cited as one of the fungi which are present in the atmosphere (Calvo et al., 1980a, Meyer et al., 1983, Oliveira et al., 1993 and Pinto et al., 1992) and soils of various areas (Calvo et al., 1984, Larrondo and Calvo, 1989 and Sarquis and Oliveira, 1996). Aspergillus was the broadest spectrum range, it represented by 16 species namely: A. awamori, A. candidus, A. flavus, A. foetidus, A. fumigatus, A. glaucus, A. janus, A. niger, A. alutaceus, A. sulphureous, A. sydowii, A. thomii, A. terreus, A. ustus, A. versicolor and A. wentii. The species which showed the highest frequency in all cases was A. flavus followed by A. niger and A. sydowii (frequency of occurrence, 97.22%, 94% and 86.11% respectively).
The third place in count and the fourth in percentage frequency was displayed by genus Chaetomium which was represented by one species namely C. murorum (83.33%). These results are inagreement with those obtained by several authors who mentioned the presence of Chaetomium murorum in beach samples (Guarro et al., 1981, Caretta et al., 1976 and Larrondo and Calvo, 1989). Trichoderma spp. (represented by T. viride), was less than C. murorum in count while higher than it in percentage frequency (91.67%).
It was worthmentioning that the total count of the genera or species in the thirty six soil samples did not always follow the number of cases of isolation. The same conclusions were obtained by Moubasher and Moustafa (1970), El-Dohlob et al. (1982), Meyer et al. (1983), Oliveira et al. (1993) and Pinto et al. (1992).
Moreover, there were no always correlation between the count and spectrum range of Aspergillus, Penicillium, Dematiaceous and Hyaline hyphomycetes species. This was due to deep fluctuations in response to alternation in condition of the atmosphere, chemical and physical analysis of the soil.
Thus, we concluded that a small number of genera with wide species diversification predominated among the total population of microflora in the sandy soil of Egyptian beaches and that they are the same universal dominants isolated from the air by several investigators. Also, peculiar and regional genera and species occured at variable, but considerably low levels. In addition to these facts, it has also to be pointed out, that the distribution of the species belonging to the studied genera varied depending on the climatic conditions, their presence in the atmosphere and chemical analysis of the soil. Thus, it would appear that coastal sands represent a large fungal reservoir whose role is little understood but is possibly important for animals, plants and the marine and terrestrial ecosystems.
REFERENCES
- El-Dohlob, S.M., J. Friend and A.A. Sherief, 1985. Xylan decomposing fungi in Egyptian soil. Proceedings of the 4th Egyptian Conference of Botany, Suez-Canal University, Ismaileyah (Egypt), April 16-19, Faculty of Science- Ismaileyah (Egypt), pp: 474-487.
Direct Link - Hawksworth, D.L., 1991. The fungal dimension of biodiversity: Magnitude, significance and conservation. Mycol. Res., 95: 641-655.
Direct Link - Kishimoto, R.A. and G.E. Baker, 1969. Pathogenic and potentially pathogenic fungi isolated from beach sands and selected soils of Oahu, Hawaii. Mycologia, 61: 537-548.
CrossRefDirect Link - De Almeida, M.G., 1997. Isolation of keratinolytic fungi from beach sand II. Portugaliae Acta Biol. Serie B, 17: 185-187.
Direct Link