Shower thoughts: why scientists should spend more time in the rain.

Stormwater is a vital resource and dynamic driver of terrestrial ecosystem processes. However, processes controlling interactions during and shortly after storms are often poorly seen and poorly sensed when direct observations are substituted with technological ones. We discuss how human observations complement technological ones and the benefits of scientists spending more time in the storm. Human observation can reveal ephemeral storm-related phenomena such as biogeochemical hot moments, organismal responses, and sedimentary processes that can then be explored in greater resolution using sensors and virtual experiments. Storm-related phenomena trigger lasting, oversized impacts on hydrologic and biogeochemical processes, organismal traits or functions, and ecosystem services at all scales. We provide examples of phenomena in forests, across disciplines and scales, that have been overlooked in past research to inspire mindful, holistic observation of ecosystems during storms. We conclude that technological observations alone are insufficient to trace the process complexity and unpredictability of fleeting biogeochemical or ecological events without the shower thoughts produced by scientists' human sensory and cognitive systems during storms.

Biodiversity of leaf litter fungi in streams along a latitudinal gradient.

Global patterns of biodiversity have emerged for soil microorganisms, plants and animals, and the extraordinary significance of microbial functions in ecosystems is also well established. Virtually unknown, however, are large-scale patterns of microbial diversity in freshwaters, although these aquatic ecosystems are hotspots of biodiversity and biogeochemical processes. Here we report on the first large-scale study of biodiversity of leaf-litter fungi in streams along a latitudinal gradient unravelled by Illumina sequencing. The study is based on fungal communities colonizing standardized plant litter in 19 globally distributed stream locations between 69°N and 44°S. Fungal richness suggests a hump-shaped distribution along the latitudinal gradient. Strikingly, community composition of fungi was more clearly related to thermal preferences than to biogeography. Our results suggest that identifying differences in key environmental drivers, such as temperature, among taxa and ecosystem types is critical to unravel the global patterns of aquatic fungal diversity.

Impact of Electron Beam Irradiation on the Bioactive Principles of Seeds of Coastal Sand Dune Wild Legumes (Canavalia spp.).

BACKGROUND: Recent patents reveal that vegetable ingredients have several applications in novel food formulations. Many so-called antinutritional components (e.g. tannins, saponins, lectins and protease inhibitors) have nutraceutical as well as pharmaceutical significance. Seeds of two wild legumes of the genus Canavalia inhabitants of the coastal sand dunes of Southwest India are known for a variety of bioactive principles (e.g. phenolics, tannins, canavanine, concanavalin and phytohemagglutinins). OBJECTIVE: This study evaluates the impact of Electron Beam (EB) irradiation on the bioactive components of seeds of two coastal sand dune wild legumes Canavalia cathartica and C. maritima. METHODS: The dry seeds of C. cathartica and C. maritima were EB irradiated with different doses (2.5, 5, 10 and 15 kGy) to follow changes in six bioactive principles (total phenolics, orthodihydric phenols, tannins, canavanine, trypsin inhibitors and phytohemagglutinins) in comparison to control seeds. One-way ANOVA was employed to follow the variation in bioactive components of seeds in control and different doses of irradiation. RESULTS: Seeds of both legumes were devoid of orthodihydric phenols and trypsin inhibitors. In C. cathartica, the total phenolics showed significant dose-dependent increase up to 5 kGy and decreased thereafter. Tannin content was not altered up to 10 kGy followed by significant decrease at 15 kGy. There was no significant change in canavanine content and the phytohemagglutinin activity against human erythrocytes was not altered. Seeds of C. maritima did not show significant changes in total phenolics as well as tannin contents. The content of canavanine showed significant dose-dependent increase up to 5 kGy followed by significant decrease. There was no variation in phytohemagglutinin activity against erythrocytes A, B and O, while against AB, the activity decreased at 2.5 kGy and further decrease was constant at higher doses. CONCLUSION: The EB irradiation doses employed have selectively altered the bioactive principles of Canavalia seeds and such treatments may facilitate to maneuver desired medicinal, nutritional, functional and cooking properties. Besides selective changes in bioactive components the seeds have extended shelf life.

Impact of Electron-Beam Irradiation on Functional Attributes of Seeds of Two Coastal Wild Legume Landraces of Canavalia.

BACKGROUND: Vegetable proteins have widespread application in the food industry as functional ingredients in food formulations according to the recent patents. Requirement to develop less expensive protein-rich supplementary foods has resulted in shift of emphasis towards lesser known wild than popular legumes. OBJECTIVE: The aim of this study is to expose seeds of two coastal sand dune wild legumes of the Southwest India (Canavalia cathartica and C. maritima) to different doses of electron-beam (EB) irradiation to assess changes in functional attributes. METHOD: Intact dried seeds were exposed to EB irradiation (2.5, 5, 10, 15 kGy). Protein solubility, gelation concentration, water-absorption capacity, oil-absorption capacity, emulsion properties and foam properties of control and irradiated seeds were assessed by standard methods. RESULTS: Protein solubility of both seed flours attained the highest at 2.5 kGy, followed by gradual dosedependent decrease. The gelation concentration increased in C. cathartica only at 5 kGy, while it decreased in C. maritima at 2.5 kGy without further change at higher doses. The water-absorption capacity of C. maritima was significantly higher than C. cathartica in control sample, while at 15 kGy C. cathartica showed significantly higher absorption capacity than C. maritima. The oil-absorption capacity was significantly higher in C. maritima than C. cathartica in control as well as all doses of irradiation. Emulsion activity of C. maritima was slightly higher than C. cathartica in control and irradiated samples, while both seeds showed similar emulsion stability in control with significant increase in C. cathartica at 10 kGy and 15 kGy. The foam capacity in both seeds was similar up to 2.5 kGy followed by significant increase in C. maritima at 5 kGy and 10 kGy. The foam stability was significantly higher C. cathartica than C. maritima in control as well as in irradiated samples. The foam capacity was higher in C. maritima than C. cathartica in control and irradiated samples, which showed gradual time-dependent decrease in stability with higher stability at 8 hr in C. cathartica than C. maritima. CONCLUSION: Improved functional properties (protein solubility, emulsion stability and foam capacity) and decreased gelation concentration in seeds of C. maritima irradiated at 5 kGy is advantageous in the production of functional foods. Even though both species of Canavalia grew on the coastal sand dunes and their seeds were exposed to same doses of radiation, they differed in functional attributes confirm that it is species-specific. Canavalia seeds being rich in proteins, carbohydrates, essential amino acids, essential fatty acids and bioactive components, further studies on the impact of EB irradiation helps in optimization of nutraceutical potential as well as functional attributes for future applications.

Edible wild mushrooms of the Western Ghats: Data on the ethnic knowledge.

The edible wild mushrooms are most important in food security of ethnic groups and tribals throughout the world. Various indigenous strategies are followed to trace wild mushrooms suitable for human consumption. Data presented in this article projects ethnic knowledge on 51 edible wild mushrooms (in 23 genera) in the Western Ghats region of India. Information collected with support of ethnic groups/tribals pertains to habitats, substrates, mutualistic association, extent of availability, extent of edibility and method of processing of wild mushrooms. Extensive field visits and interactions with ethnic groups were performed to collect the data on each mushroom. Initially, most of these mushrooms were identified based on the indigenous methods and designated with vernacular names (Are-Gowda, Kodava and Tulu). Based on macromorphology (in field) and micromorphology (in laboratory), each mushroom was identified with its systematic name. Among the 51 wild mushrooms irrespective of extent of availability, the most preferred include Astraeus hygrometricus, Clitocybe infundibuliformis, Fistulina hepatica, Lentinus sajor-caju, Pleurotus (5 spp.) and Scleroderma citrinum and Termitomyces (18 spp.). This data forecasts the importance of documentation of traditional knowledge, protection of habitats, management of resources (tree species and substrates) and sustainable exploitation of wild mushrooms.

Fatty Acid Composition of Mangrove Wild Legume Seeds (Sesbania speciosa) in Southwestern India.

BACKGROUND: This study compares the composition of fatty acid methyl esters (FAMEs) in seeds of Sesbania speciosa (dry and mature) after processing (uncooked and cooked) and extraction (hot and cold). METHODS: Among PUFA, oleic, linoleic and linolenic acids were common to uncooked and cooked dry seeds which were high on cold extraction. Only two fatty acid ratios were favorable in hot extraction [(C14:0 + C15:0 + (C16:0 / C18:0) and C18:1 / C18:2]. RESULTS: Cold extraction yielded docosahexaenoic acid in uncooked as well as cooked dry seeds and all fatty acid ratios were nutritionally favorable. In mature seeds, lauric and myristic acids were high on hot extraction, while palmitic and stearic acids were high on cold extraction. Except for ω-6/ω-3 ratio, the rest fatty acid ratios in mature seeds on hot extraction were not favorable, while cold extraction resulted in three favorable ratios (TUFA/TSFA, TPUFA/TMUFA and ω-6/ω-3). Three-way ANOVA on the impact of seeds, process and extraction of major fatty acids revealed significant difference only between extraction methods (p < 0.001). CONCLUSION: Overall, the cold extraction for dry as well as mature seeds were advantageous for essential fatty acids profile. Some of the recent patents are dealing with antineoplastic compounds as well as radioprotective drugs derived from Sesbania speciosa.

Impact of fire on the macrofungal diversity in scrub jungles of south-west India.

Fortnightly survey in control and fire-impacted regions of scrub jungle of south-west coast of India during south-west monsoon (50 m2 quadrats up to 10 weeks) yielded 34 and 25 species of macrofungi, respectively. The species as well as sporocarp richness were the highest during the fourth week, while the diversity attained the highest during the second week in control region. In fire-impacted region, the species and sporocarp richness and diversity peaked at sixth week. Seven species common to both regions were Chlorophyllum molybdites, Lepiota sp., Leucocoprinus birnbaumii, Marasmius sp. 3, Polyporus sp., Schizophyllum commune and Tetrapyrgos nigripes. The overall sporocarp richness was higher in fire-impacted than in control region. The Jaccard's similarity between regions was 13.5%, while fortnights of regions ranged from 0% (10th week) to 11.7% (eighth week). Control region showed single-species dominance by Xylaria hypoxylon, while multispecies dominance by Cyathus striatus and Lentinus squarrosulus in fire-impacted region. Except for air temperature, nine abiotic factors significantly differed between control and fire-impacted regions. The Pearson correlation was positive between species richness and phosphorus content in fire-impacted region (r = 0.696), while sporocarp richness was negatively correlated with pH in control region (r = -0.640). Economically viable species were 12 and 10 without overlap in control and fire-impacted regions, respectively.

Diurnal periodicity of conidia of aquatic hyphomycetes in water and entrapment on latex-coated slides in two South Indian streams.

Aquatic hyphomycete conidial trapping efficiency by the banyan (F. benghalensis L.) latex-coated glass slides was tested diurnally (3 h intervals) in the Western Ghats (Sampaje) and west coast (Konaje) streams in relation to abiotic factors (humidity, air temperature and water temperature). The conidial trapping efficiency of latex-coated slides was compared with plain glass slides and drift conidia in water. Three methods of assessment showed higher species richness, conidial richness and diversity in Sampaje than in Konaje stream. In both streams, species richness, conidial richness and diversity in latex-coated slides were the highest followed by conidia in water and plain slides. Three-way ANOVA revealed significant differences in overall species and conidial richness between the streams, sampling methods and time of sampling (p < 0.001). Multiple comparisons by Holm-Sidak test revealed significant differences in overall species and conidial richness between Sampaje and Konaje (p < 0.001); latex-coated slides and plain slides (p < 0.001); latex-coated slides and water filtration (p < 0.001); plain slides and water filtration (p < 0.001). Total species, total conidia and diversity assessed by the three methods peaked during 12 am-3 am in Sampaje stream, while during 3 am-6 am in Konaje stream. Cooler conditions due to relatively low water temperature favoured higher diversity of aquatic hyphomycetes in Sampaje than in Konaje stream. The three methods employed in the present study were not biased towards scolecoid or stauroid conidia. The top five species in both streams was composed of both types of conidia corroborating earlier annual or biannual studies in Konaje and Sampaje streams. Thus, assessment of population of aquatic hyphomycetes using banyan latex-coated slides will be advantageous over plain slides and drift conidia in streams.

Bioactive potential of the wild mushroom Astraeus hygrometricus in South-west India.

The wild mushroom Astraeus hygrometricus is a traditional delicacy during the monsoon season in South-western India. Bioactive principles and antioxidant potential of uncooked and pressure-cooked tender mushroom have been evaluated. Seven bioactive principles of mushroom (tannins, flavonoids, vitamin C, phytic acid, lycopene, ß-carotene and trypsin inhibition) were significantly higher, while total phenolics content was significantly lower in uncooked than in cooked samples. Mushroom was devoid of L-DOPA, whereas only uncooked samples showed haemagglutinin activity against A+ blood group. The principal component analysis of uncooked mushroom showed only two bioactive principles clustered with two antioxidant properties, while in cooked mushroom five bioactive principles clustered with three antioxidant properties depicting the nutraceutical potential of cooked mushroom. Future studies should focus on appropriate thermal treatment, which retain maximum bioactive and antioxidant potential to combat health- and lifestyle-related ailments. The A. hygrometricus is ectomycorrhizal, conservation of its host tree species is utmost importance in improvement and expansion of its yield to sustain food security and economic gains of local tribals.

A new technique to monitor conidia of aquatic hyphomycetes in streams using latex-coated slides.

We examined the pattern of adherence of aquatic hyphomycetes conidia on six latex-coated slides (Artocarpus heterophyllus, A. hirsutus, Calotropis gigantea, Ficus benghalensis, Manilkara zapota and Plumeria rubra) with plain slides (control) exposed up to 18 h in a tropical coastal stream. Conidia of 21 species were trapped on latex-coated slides against seven on control slides. The total conidia adhered on latex-coated slides was higher than control slides. Latex-coated slides showed the highest diversity of aquatic hyphomycetes than control slides (1.805) and water (0.729). The top five species of aquatic hyphomycetes in latex-coated slides and drift conidia were comparable. Sørensen's similarity of species in control slides against latex-coated slides ranged from 25% (P. rubra) to 62.5% (C. gigantea) indicating superiority of latex-coated slides in conidial trapping. Among the latex-coated slides, similarity varied between 13.3% (A. hirsutus vs. P. rubra) and 89.6% (F. benghalensis vs. M. zapota). One-way ANOVA showed significant difference in richness of species (P < 0.001) and conidia (P < 0.05) between control and latex-coated slides by F. benghalensis. Based on the trapping efficiency of species and conidia, the latex of F. benghalensis ranked first and serves as an inexpensive technique to monitor aquatic hyphomycetes in streams.

Nutritional composition of two wild mushrooms consumed by the tribals of the Western Ghats of India.

This study provides the nutritional qualities of two wild mushrooms (Agaricus abruptibulbus and Termitomyces globulus) commonly consumed by the tribals of Kaiga forests of the Western Ghats of India. Both mushrooms composed of high quantity of crude protein, crude fibre, calorific value and low quantity of crude lipid. Potassium and selenium contents were high, while sodium, calcium and phosphorus contents were low. Except for three essential amino acids (EAAs: leucine, tyrosine and lysine), the rest of the amino acids in both mushrooms were comparable to soybean and wheat. Based on the EAA standards of FAO-WHO, these mushrooms composed of high quantity of threonine, isoleucine and histidine. The EAA score of isoleucine in cooked A. abruptibulbus and threonine, isoleucine, phenylalanine, histidine and sulphur amino acids in cooked T. globulus were substantially high. Oleic acid constitutes a major unsaturated fatty acid in these mushrooms, which was significantly increased in cooked A. abruptibulbus. Cooking also increased the ratio of TUFA/TSFA in A. abruptibulbus, while it was opposite in T. globulus. Cooking significantly increased the linoleic acid in A. abruptibulbus and eicosadienoic acid in T. globulus.

Antioxidant activity of raw, cooked and Rhizopus oligosporus fermented beans of Canavalia of coastal sand dunes of Southwest India.

The raw and processed (cooked and cooked + solid-state fermented with Rhizopus oligosporus) split beans of two landraces of coastal sand dune wild legumes (Canavalia cathartica and Canavalia maritima) of the southwest coast of India were examined for bioactive compounds (total phenolics, tannins and vitamin C) and antioxidant potential (total antioxidant activity, ferrous-ion chelating capacity, DPPH free radical-scavenging activity and reducing activity). One-way ANOVA revealed significant elevation of bioactive compounds as well as antioxidant activities in fermented beans compared to raw and cooked beans in both legumes (p < 0.001). The EC50 values in fermented beans of both legumes were significantly lowest compared to raw and cooked beans (p < 0.001). In principal component analysis, total phenolics along with antioxidant activities (total antioxidant, ferrous-ion chelating and free radical-scavenging activities) of fermented beans of C. cathartica, while total antioxidant and free radical-scavenging activities of fermented beans of C. maritima were clustered. The present study demonstrated that split beans of coastal sand dune Canavalia fermented by R. oligosporus endowed with high bioactive principles as well as antioxidant potential and thus serve as future nutraceutical source.

Reproduction of aquatic hyphomycetes at low concentrations of Ca2+, Zn2+, Cu2+, and Cd2+.

Maple leaf disks were conditioned in a stream for three weeks and then aerated for 2 d in distilled water to induce fungal sporulation. The release of aquatic hyphomycete spores increased when the water was supplemented with low concentrations of Ca(2+) (5 µg/L), Zn(2+) (2.5 µg/L), Cu(2+) (0.5 µg/L), or Cd(2+) (0.125 µg/L). Higher supplement concentrations inhibited sporulation. Over the concentration range used, the sporulation response was generally best described by a quadratic regression, suggesting a biphasic or hormetic response. A similar pattern was found with the number of fungal species as the dependent variable. Anguillospora filiformis and Anguillospora longissima were generally least inhibited by metal supplements, and Ca(2+) was the least and Cd(2+) the most toxic metal. Combinations of metals had a more severe effect on fungal sporulation than predicted from addition of the effects of the metals in isolation. The biological significance of the hormetic response is unclear; however, acknowledging it is clearly relevant for establishing guidelines or recommendations in toxicology.

Effects of 4-n-nonylphenol on aquatic hyphomycetes.

We measured the removal of 4-n-nonylphenol (between 50 and 500 µg L(-1)) from an aqueous solution with or without linden and oak leaf disks. More 4-n-NP was removed when the leaves were first exposed for 3 weeks in a stream, which allowed colonization by aquatic hyphomycetes. The response of fungal sporulation rates from beech, linden, maple and oak leaves to increasing levels of 4-n-NP was complex. Linear regressions were non-significant, arguing against a no-threshold model. The response at the lowest concentration (50 µg L(-1)) was between 7% (beech) and 67% (maple) higher than in the absence of 4-n-NP, however, the difference was not significant. The number of sporulating species of aquatic hyphomycetes was significantly higher at the lowest concentration than in the control treatment without 4-n-NP. The composition of the fungal community was affected by leaf species but not by 4-n-NP concentration. The results suggest the presence of a weak hormeotic effect. The known ability of aquatic hyphomycetes and other fungi to degrade nonylphenols and related substances, combined with fungal resilience in their presence, makes decaying leaves potential candidates for bioremediation.

The spatial distribution of fungi on decomposing woody litter in a freshwater stream, Western Ghats, India.

We mapped filamentous fungal association with mechanically "hard" and "soft" woody litter naturally deposited in a stream of the Western Ghats of India. Using a durometer (rubber hardness tester), the toughness of surface of wood collected from stream was determined by considering durometer reading from 60-72 to 30-37 as hardwood and softwood, respectively. From each wood (1.5 cm diameter), two segments each of 3 cm length were excised and vertically cut into nine sections comprising eight marginal and one central section. From three stream locations, hardwood and softwood sections were assessed for the occurrence of lignicolous and Ingoldian fungi. A first set of wood sections was incubated in damp chambers up to 4 months with periodical screening (every 2 weeks) for lignicolous fungi. Another set was incubated in bubble chambers up to 72 h to ascertain colonization of Ingoldian fungi. In hardwood sections, 17 lignicolous fungi (ascomycetes, four; mitosporic fungi, 13; mean, 6.8; range, 6-8/section) and ten Ingoldian fungi (mean, 2; range, 0-4/section) comprising nine lignicolous (11.1-40.7%) and three Ingoldian (11.1-14.8%) fungi as core-group taxa were recovered. In softwood, ten lignicolous fungi (ascomycetes, 0; mitosporic fungi, ten; mean, 3.8; range, 2-5/section) and 26 Ingoldian fungi (mean, 8.1; range, 5-10/section) comprising six lignicolous (11.1-85.2%) and 12 Ingoldian (11.1-88.9%) fungi as core-group taxa were recovered. The ratio of lignicolous fungi/Ingoldian fungi was higher in hardwood than softwood (1.7 vs. 0.4). The spore output of Ingoldian fungi was higher in softwood (mean, 901 g(-1); range, 80-2546 g(-1)) than hardwood (mean, 21 g(-1); range, 0-140 g(-1)). The Shannon diversity of lignicolous fungi was higher in hardwood than softwood (3.604 vs. 2.665), whereas it was opposite for Ingoldian fungi (3.116 vs. 3.918). The overall fungal diversity was higher in softwood than hardwood (4.413 vs. 4.219). The range of Jaccard's index of similarity among wood sections was higher in lignicolous fungi (8-71% and 13-75%) than Ingoldian fungi (0-50% and 8-55%) in hardwood and softwood. The rarefaction indices of expected number of taxa against hardwood sections revealed higher and persistent lignicolous fungi than the Ingoldian fungi, while the Ingoldian fungi were persistent in softwood sections, although they were lower than lignicolous fungi. Our study demonstrated the dominance of lignicolous fungi and Ingoldian fungi in hardwood and softwood, respectively.

Nutritional quality evaluation of velvet bean seeds (Mucuna pruriens) exposed to gamma irradiation.

Effects of gamma irradiation on Mucuna pruriens seeds at various doses (0, 2.5, 5, 7.5, 10, 15 and 30 kGy) on the proximate composition, mineral constituents, amino acids, fatty acids and functional properties were investigated. Gamma irradiation resulted in a significant increase of crude protein at all doses, while the crude lipid, crude fibre and ash showed a dose-dependent decrease. Raw Mucuna seeds were rich in minerals (potassium, phosphorus, calcium, magnesium, iron and selenium). Sodium, copper and manganese were significantly decreased on irradiation at all the doses, while magnesium and iron showed a significant decrease only above 10 kGy. The essential amino acids of raw and gamma-irradiated Mucuna seeds were comparable with the FAO/WHO recommended pattern. A significant increase of in vitro protein digestibility was seen in seeds irradiated at 30 kGy. High amounts of unsaturated fatty acids in Mucuna seeds decreased significantly after irradiation. However, linoleic acid was not present in raw seeds but detected after irradiation and it was elevated to high level at 30 kGy. Behenic acid, a major anti-nutritional factor, was reduced significantly on irradiation, indicating the positive effect of gamma irradiation on Mucuna seeds. Significant enhancement in the water absorption and oil absorption capacities, protein solubility, emulsion activity and improvement in the gelation capacity was recorded after irradiation. Results of the present investigation reveal that application of gamma irradiation does not affect the overall nutritional composition and can be used as an effective method of preservation of Mucuna seed and their products.