Deterioration and spoilage of peanuts and desiccated coconuts from two sub-Saharan tropical East African countries due to the associated mycobiota and their degradative enzymes

A broad variety of fungi (84 species belonging to 36 genera) were identified with more taxa infesting peanut seed samples from two tropical countries (29 genera and 61 species) compared to those found in desiccated coconuts (20 genera and55 species) on both DRBC and DG18 media. This may be due to the higher moisture levels in peanuts (5.07–7.97%) compared with coconuts (1.5–4.17%). More taxa and propagules were recovered on DG18 in both cases. The dominant fungi from both substrates on both isolation media were Aspergillus andPenicillium, with other fungi from only one substrate/medium. The aflatoxigenic species (A. flavus) dominated Kenyan samples more so than Ugandan samples on both substrates. However only71.5% and 87% of the peanut kernels, on DRBC and DG18, respectively, were found to be infested with fungi. The aflatoxigenic species (A. flavus/parasiticus)were found in 75% of the samples, however only 15.75% and 13%of the kernels analyzed were infested. The most frequently isolated species from peanuts were A. niger followed by A. flavus and M. phaseolina. E. repens, E. amstelodami,E. rubrum and E. chevalieri dominated peanut seeds on DG18, and R. stolonifer, A. parasiticus,F. solani, L. theobromae and P. chrysogenumon DRBC. The mean count of fungal propagules in coconut samples were approximately 0.7× 10³ and 0.8× 10³on DRBC and DG18, respectively, with a high proportion of those propagules recorded for the aflatoxigenic species (about 0.17×10³ and 0.25× 10³ colonies/g). The mycobiota of desiccated coconut was dominated by A. niger, A. flavusand P. chrysogenum. Also A. ochraceu,P. waksmanii, Paecilomyces variotii,P. islandicum and R. mucilaginosa were more frequent on DRBC, while, species of Cladosporium,Chrysosporium and Eurotium were more frequent on DG18. Enzyme indices (or the activities) for each specific strain, when determined after 5 and 8 days of incubation, proved to be similar. A recommendation is given. The proteolytic and lipolytic potentialities of the most commonly encountered species from both peanuts and coconuts were studied. The most interesting observation is that most of the positive isolates, in both commodities had high enzymic activity compared to those reported earlier for isolates of the same species. Such capabilities suggest that these commodities are expected to deteriorate, since climatic conditions in tropical areas favour fungal proliferation. Emphasis on the proper harvesting, drying, handling, transportation and/or storage; and also education of the populace, especially those are dealing with these foods, should be taken into consideration by the relevant authorities. The contaminated foods constitute a health hazard for human consumption. This revised version was published online in June 2006 with corrections to the Cover Date.     

Abundance and diversity of microfungi in three coastal beaches of Mexico

The abundance and diversity of species of microfungi was investigated on the beaches of Delfines, Km 24 Veracruz-Alvarado Highway, and El Coco, located on the coasts of the Caribbean Sea, Gulf of Mexico, and the Pacific Ocean, respectively. On each beach a sample composed of sand, subtidal wood or washed-up detritus with moist sand was collected. The samples were analyzed by three different methods, resulting in a total of 1,160 occurrences that fluctuated between 340 and 441 occurrences/sample. The number of species/sample fluctuated between 20 and 32. A total of 52 species was found, of which 12 were marine, and 40 nomarine, of terrestrial origin, and of these 15 were ascomycetes, 34 were hyphomycetes, 2 were blastomycetes and one was a coelomycete. The abundance distribution showed few species with high or low values, with the greates proportion having intermediate values. In order to compare species diversity among the samples frequency curves were utilized, based on the number of species expected from samples taken at random; the results showed that the beach at El Coco was richest in species.     

Fungal species diversity in juvenile and adult leaves of Eucalyptus globulus from plantations affected by Mycosphaerella leaf disease

In recent years, Mycosphaerella leaf disease (MLD) has become very common in Eucalyptus globulus plantations in Galicia, northwest Spain. The aetiology of MLD is complex and is associated with several species of Mycosphaerella and Teratosphaeria. A survey of the fungal mycobiota associated with juvenile and adult leaves and with leaf litter of the same trees in MLD‐affected plantations was made. The goal was to identify pathogens and endophytes, to determine whether the mycobiota of each leaf type differed and whether leaf litter might be a reservoir of MLD inoculum. Fungi belonging to 113 different species were isolated from the leaves of juvenile and adult trees sampled at 10 locations; 81 species occurred in juvenile and 65 in adult leaves. The average number of species obtained from juvenile leaves was significantly greater (P > 0.01) compared to adult leaves. This difference suggested that juvenile leaves are not only more susceptible to a group of pathogens, but to a wide range of fungi. Therefore, a general resistance mechanism might be lacking or be less effective in juvenile than in adult leaves. Several pathogenic species were identified in both leaf types. Leaf litter and living leaf mycobiotas were very different. However, some of the species they shared were MLD pathogens, suggesting that leaf litter could contribute to the inoculum of MLD.     

Pod and Seed Mycoflora on Transgenic and Conventional Soybean [Glycine max (L.) Merrill] cultivars in Mississippi

A 2-year (1999-2000) study was conducted at Starkville and Stoneville, MS to determine if the occurrence of the mycoflora varied on Roundup Ready (transgenic) compared to conventional soybean (Glycine max) cultivars. A total of 7,658 fungal isolates were identified from the pod and seed tissues of four cultivars compared at growth stages R6 and R8. Ninety-nine percent of all fungi isolated were mitosporic fungi and ascomycetes. In both years, total fungal isolates from the two locations were greater from the pod (65%) than from seed (33%) tissues. Isolation frequency from conventional cultivars was 54% compared to 46% for the transgenic cultivars. The most common fungi identified that are reported pathogens of soybean included Alternaria, Cercospora, Cladosporium, Diaporthe, Fusarium and Verticillium spp. When main effects and interactions were compared among the frequency data for the fungal genera, significant differences occurred, but consistent trends were not noted. Isolation frequencies of Diaporthe spp. during the R6 growth stage, were significantly greater on the conventional than on the transgenic cultivars in both years of the study, but only at Starkville. Isolation frequencies from samples taken during the R8 growth stage were similar at both locations in 1999 and 2000. Fusarium spp. isolated at R6 and R8 growth stages from pod and seed tissues were significantly greater on conventional than on transgenic cultivars in 2000. Even though frequencies were often significantly different between the transgenic and conventional cultivars, the data was not consistent between locations, pod and seed tissues, or growth stages. The pod and seed mycoflora of transgenic and conventional soybean cultivars was, therefore, similar in Mississippi.     

Notes on the boletes of Japan 1. Four new species of the genus Boletus from central Honshu,Japan

Four new species of Boletus are fully described and illustrated from central Honshu, Japan: (1) B. panniformis (Section Calopodes) produces a typically felted and scabrous pileus, bitter flesh, a finely reticulate, red stipe, and occurs in subalpine, coniferous forests; (2) B. ventricosus (Section Appendiculati) forms a usually ventricose or subbulbous stipe, yellow to greyish orange, extremely short tubes, often pluriseptate, broadly clavate to doliform caulocystidia, and occurs in lowland, mixed forests; (3) B. cepaeodoratus (Section Appendiculati) possesses a pinkish red pileus, a usually finely reticulate stipe, relatively short tubes, and occurs in lowland, mixed forest; (4) B. viscidipellis (Section Luridi) yields a hairy, viscid pileus, intensely cyanescent flesh, and occurs in lowland, mixed forests.     

Determination of mycobiota and mycotoxins in pig feed in central Argentina

Aims: To evaluate the mycobiota and natural levels of aflatoxins, fumonisins and zearalenone present in compound feed and home‐corn grains intended for fattening pigs. Methods and Results: Total fungi, Fusarium and Aspergillus species occurrence were examined. Aflatoxins and zearalenone were detected by thin‐layer chromatography and fumonisins by high‐pressure liquid chromatography. Fungal counts were generally higher than 1 × 10⁵ colony forming units (CFU) ml^?1. Aspergillus flavus, Aspergillus parasiticus and Fusarium verticillioides were the most prevalent species. FB₁ and FB₂ were detected in all feed and corn samples. Aflatoxin B₁ was detected in 33·33% of initial and growing feed and in 44·44% of final feed samples. It was not detected in corn samples. All feed and corn samples were negative for AFB₂, AFG₁, AFG₂ and ZEA presence during all growing stages tested. Conclusions: Fungal counts at all growing periods exceeded the levels proposed as feed hygienic quality limits. Aflatoxin levels in all feeds and fumonisin levels in many samples were higher than the established regulations. Significance and Impact of the Study: The presence of mycotoxins indicates the existence of contamination. This fact requires periodic monitoring to prevent the occurrence of mycotoxicosis in animal production, to reduce the economic losses and to minimize hazards to human health.     

Hair and scalp mycobiota in school children in Nablus area

Hair and scalp mycobiota of 1389 clinically normal children aged 6–12 years attending 12 schools in the Nablus District, Palestinian Authority, was assessed on three occasions over 8-month period (October 1998–May 1999) using the hair brush technique. One hundred and one fungal species belonging to 33 genera were recovered: 6 dermatophytes, 16 dermatophyte-like keratinophilic fungi, and 79 other keratinophilic fungal species. Species varied considerably in their frequency of occurrence and abundance based on their relative importance values (RIVs). The most frequent and abundant species were: Cladosporium cladosporioides, Cl. herbarum, Penicillium chrysogenum and Aspergillus flavus. Microsporum canis, Aphanoascus fulvescence and Chrysosporum sulfureum were the most frequent and abundant species of all dermatophytes and dermatophyte-like keratinophilic fungi recovered. The most frequent and abundant dermatophytes in different communities were M. canis in rural (RIV 0.87) and urban children (0.45), and Trichophyton violaceum (1.41) in refugee camp children. Chrysosporium species were the most frequent and abundant dermatophyte-like keratinophilic fungus in children from all localities followed by Aphanoascus fulvescence. Comparable results on the frequency and abundance of human hair and scalp mycobiota component fungi were obtained based on age group and sex of children. Higher number of species was recovered in spring months (73 species) than in autumn (57) and winter (44) months. Similar occurrence pattern was also noted for dermatophyte-like keratinophilic species and dermatophytes. Higher percentages of children with moderate (11–50) and heavy (≤ 50) spore loads (7.54 and 0.73, respectively) were found in urban school children community than in rural and refugee camp school children (4.7 and 0.1, respectively). Also significantly higher light (1–10) spore load percentages were found in rural (63.67) and refugee camp (62.9) than in urban children (52.6). Of all localities, school children with light spore load comprised the highest percentage of the children examined (37.4), followed by moderate (6.13), and heavy (0.41) spore load categories. However, children with undetected spore load comprised 36.05% of all children. Spore load distribution did not show clear seasonal variations in the study period. Higher percentages of moderate and heavy spore loads were found in male children (8.72 and 0.69, respectively) than in female children (3.4 and 0.1, respectively). However, higher percentages of undetected (38.3) or light spore loads (58.4) were found in females than in males (34.04 and 56.53, respectively). This revised version was published online in June 2006 with corrections to the Cover Date.     

山东省烟草根际土壤真菌多样性研究

为了有助于研究烟草根际土壤真菌与根茎病害发生程度的相互关系,文中对采自山东省6个地区的122份烟草根际土壤样品进行了真菌的分离和培养,采用形态学方法进行鉴定,并分析了菌群的多样性组成。从山东烟草根际土壤中分离和鉴定出真菌22属79种,其中接合菌门4属6种,子囊菌门1属1种,无性型真菌17属72种。优势真菌种群为青霉属(Penicillium)、木霉属(Trichoderma)、镰孢菌属(Fusarium)和曲霉属(As-pergillus),所占分离真菌总菌数的比例分别为22.39%、13.62%、12.69%和9.88%。6个采样地区间真菌菌群的多样性水平存在差异,其中诸城地区的多样性指数(H′=2.066 6)、均匀度指数(J=0.689 8)和丰富度指数(R=3.730 1)均最高。     

Uromyces umiamensis, a new rust species on Momordica cochinchinensis in India

Uromyces umiamensis is described as a new rust fungus (Basidiomycota, Uredinales) of Momordica cochinchinensis (Cucurbitaceae) from Meghalaya, in northeastern India. The species differs from the known Uromyces species on members of Cucurbitaceae in terms of the character of the teliospores and aeciospores and its apparently demicyclic life cycle. Besides U. yakushimensis and the present species, all Uromyces species known from cucurbits occur in the New World. A key to known Uromyces species on Cucurbitaceae is provided.