Debasmita Ghosh

Bio: Debasmita Ghosh is an academic researcher. The author has contributed to research in topics: Bioaerosol & Alternaria tenuissima. The author has an hindex of 2, co-authored 2 publications receiving 14 citations.

Identification and distribution of aeromycoflora in the indoor environment of Shyambazar Metro-Railway Station, Kolkata, India

Abstract: Concentrations of fungal spores constitute a significant amount in bioaerosol depending on geographical regions and seasonal variations. Mycotoxin producing spores have adverse effects on humans. The aim of the study was to evaluate the prevalent species of airborne fungi in the indoor environment of the Shyambazar Metro-Railway Station, Kolkata, India. This area is below the ground level and fully surrounded, with constant movement of commuters. It is warm and humid with temperature and humidity ranges of 26.8 to 35.9°C and 50 to 88.3% respectively. Air sample was collected for four months within the interval of two weeks by means of gravitational settling method via Petri dishes with Potato Dextrose Agar (PDA) culture media. Those fungi colonies that formed after an incubation period of 3 to 5 days at 25 to 28°C were determined on the basis of micro and macro morphological characteristics. In this investigation, among fourteen spore types,Aspergillus niger was the most prevalent fungal genera followed by Aspergillus flavus andPenicillium sp. In addition, five sterile types and one unidentified species were also detected. The variation in the number of fungal colony was observed after every two weeks, in the summer months. The results of this investigation appeared to be quite significant for taking corrective measures. Key words: Bioaerosol, aeromycoflora, mycotoxin, fungal spore, metro-railway station.

Study of aeromycoflora in indoor and outdoor environment of national library, kolkata

Abstract: We aimed at the systematic evaluation of air-borne fungal flora of the National Library, Kolkata for a period of three months beginning from February to April, 2010 to determine their identification, concentration and diversity in both indoor and outdoor environment to understand the cumulative aeromycoflora composition. The period of study was the post winter period followed by pre-summer months that was mild to moderate warm and low to high humid condition with temperature and humidity ranges of 17.0-38.2°C and 26-92% respectively. Air sample was collected with interval of two weeks by means of gravitational settling method using petri dishes with Malt Extract Agar (MEA) media. Fungal colonies that formed after 3-5 days incubation period at 25-28°C were identified on the basis of micro and macro morphological characteristics and finally percentage contributions of individual fungal species were calculated. A total of 21 types of fungal spores were identified from indoor environment with 5 sterile hyphae and 13 unidentified spore types. In case of outdoor environment, total number of spore types encountered was 19 along with 12 sterile hyphae and 6 miscellaneous types were recorded under unidentified spore type. The prevailing presence of Aspergillus niger, Alternaria tenuissima, Cladosporium herbarum and Penicillium sp. were accounted for a high percentage in indoor environment whereas outdoor environment showed clear dominance of Alternaria alternata, Asperillus niger, Alternaria tenussima, Cladosporium herbarum, Cladosporium cladosporioides, Curvularia lunata and Fusarium oxysporum. Among all the fungal spore types the taxonomic group Deuteromycotina showed dominance in total spore contribution. Biomonitoring of aeromycoflora is a key to open the information of sensitivity towards bioaerosol in this atmosphere and our findings may be useful with regard to the investigation of corrective measures to save the library materials from fungal damage and diagnosis and prophylaxis of allergic diseases resulting from aeromycoflora composition of this environment.

Belowground Defence Strategies in Plants

Abstract: Plant roots have long been literally and figuratively hidden from sight, despite their unmistakable importance in a plant’s life. Interactions between plant roots and soil microbes indeed seem to take place in a black box, but science is starting to shed some light into this box. This book aims to bring together our current knowledge on the belowground interactions of plant roots with both detrimental and beneficial microbes. This knowledge can form the basis for more environmentally friendly plant disease management of soil-borne pathogens and pests, and the book will be of interest to both plant scientists and students eager to discover the hidden part of a plant’s daily life and survival. Plants are multicellular photosynthetic organisms that have evolved from unicellular fresh water green algae. During their evolution, plants have acquired diverse capabilities that enabled them not only to survive but also to adapt and successfully colonize diverse land environments. In particular, the acquisition of roots or rootlike structures that facilitate extracting water from soil rather than relying on limited amounts of moisture available on the soil surface has no doubt played an important role in plant’s adaptation to life on land. Obviously, roots are also essential for physical attachment of plants to the soil, as well as for nutrient uptake and interaction with soil biota. Plant roots continuously C.M.F. Vos (*) Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie (VIB), Technologie park 927, 9052 Ghent, Belgium Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture, 306 Carmody Road, St Lucia, Brisbane, QLD 4067, Australia Scientia Terrae Research Institute, Fortsesteenweg 30A, Sint-Katelijne-Waver, Belgium e-mail: cvo@scientiaterrae.org K. Kazan CSIRO Agriculture St Lucia, 306 Carmody Road, St Lucia, QLD 4067, Australia The Queensland Alliance for Agriculture & Food Innovation (QAAFI), Queensland Bioscience Precinct, University of Queensland, Brisbane, QLD 4072, Australia © Springer International Publishing Switzerland 2016 C.M.F. Vos, K. Kazan (eds.), Belowground Defence Strategies in Plants, Signaling and Communication in Plants, DOI 10.1007/978-3-319-42319-7_1 1 explore the soil to sense and transmit diverse belowground signals needed to modify plant architecture. The interaction between plant roots and beneficial microbes (e.g., rhizobia or arbuscular mycorrhiza) can be highly advantageous for both parties and greatly contributes to agriculture. However, the belowground environment can be very hostile as well and plant roots are often threatened by various biotic and abiotic stress factors (e.g., lack of water, oxygen, nutrients; soil acidity, salinity, low temperatures, as well as pathogenic microbes). While the interaction between roots and nonpathogenic microbes can be beneficial, many pathogenic microbes and nematodes can inflict serious damage to roots, restricting plant growth, reducing yield, and even causing plant death. Therefore, plants must differentiate friends from foes to survive in a hostile environment, and the soil and plant roots play essential roles in this process. Despite the importance of plant roots in the overall well-being of plants, crop breeding efforts aimed at improving biotic and abiotic stress tolerance have so far been mostly focused on the aboveground part of the plant. In fact, the roots are often referred to as “the hidden half,” or the “black box,” reflecting the neglected nature of plant root research. Similarly, although root pathogens cause enormous losses on our crop plants, root health has always been a difficult issue to deal with. Possible reasons for this are probably numerous but mainly include the complexity of the belowground environment. Better understanding of the nature of the interaction between plant roots and both beneficial and pathogenic microbes can generate new knowledge leading to the development of novel strategies aimed at boosting plant productivity, while reducing crop losses. As Editors of this Springer book, our objective is to contribute to the ongoing efforts in this area by bringing together contributors who are leading researchers in their respective areas. The first part of the book focuses on the general plant responses to soil microbes and the role that root exudates play in this process, both highly active research domains. The first chapter of this part (chapter “Belowground Defence Strategies in Plants: Parallels Between Root Responses to Beneficial and Detrimental Microbes”) highlights the parallels that are increasingly emerging in plant root responses to beneficial and pathogenic microbes. The next chapter (chapter “Root Exudates as Integral Part of Belowground Plant Defence”) details the essential and versatile roles of root exudates in belowground plant defences, impacting both detrimental and beneficial microbes. The second part of the book then zooms in on the belowground defence strategies against specific root pathogens. Fungal root pathogens are represented by Fusarium oxysporum (chapter “Belowground Defence Strategies Against Fusarium oxysporum”), Rhizoctonia (chapter “Belowground Defence Strategies Against Rhizoctonia”), and Verticillium (chapter “Belowground Defence Strategies Against Verticillium Pathogens”). Next in line are the plant root responses to the oomycete pathogens Phytophthora (chapter “Belowground and Aboveground Strategies of Plant Resistance Against Phytophthora Species”) and Pythium (chapter “Belowground Signaling and Defence in Host–Pythium Interactions”). Protists are represented by the clubroot pathogen Plasmodiophora brassicae (chapter 2 C.M.F. Vos and K. Kazan

Root Interactions with Nonpathogenic Fusarium oxysporum

Abstract: In this review, we tried to present Fusarium oxysporum in an ecological context rather than to confine it in the too classic double play of the nonpathogenic fungus that protects the plant against the corresponding forma specialis. Moreover, F. oxysporum is sometimes one, sometimes the other, and only the fungus can reveal its hidden face, according to it is or not in front of the target plant. Despite the quality and richness of the studies conducted to date, molecular approaches highlight some of the evolutionary mechanisms that explain the polyphyletic nature of this species, but still they do not identify a nonpathogenic F. oxysporum.

Temporal Dynamics of Air Bacterial Communities in a University Health Centre Using Illumina MiSeq Sequencing

Abstract: Bacterial contamination of air may have human health implications by the transmission of potential human pathogens. Therefore, assessment of air bacterial abundance and composition in different built environment is essential. Jawaharlal Nehru University health centre (UHC) is a primary healthcare setting providing need-based medication to university students. Using active air sampling method, we collected eight air samples from the indoor and outdoor area of UHC across four different seasons. The total genomic DNA was extracted from the air samples and subjected to 16S rRNA gene-based next-generation sequencing. We performed the taxonomic classification along with comparative analysis of air bacterial communities. This study revealed that Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes are the dominant phyla in the sampled air. Overall, the air bacterial composition in our studied samples was comparatively simple; only ten taxonomic families accounting for ~75% of the total sequences determined. We also observed ESKAPE pathogens in the air metagenomes in a low percentage (4.42%), which were dominated by Pseudomonas, Acinetobacter and Staphylococcus. Proteobacteria, Actinobacteria and Firmicutes showed significant correlation with PM2.5. We suggest that routine air monitoring and microbiological survey is essential for air quality standards and potential human pathogens detection in health care settings. It is the first report from India to uncover the temporal dynamics of air bacterial communities in UHC using Illumina MiSeq (PE300) sequencing and Quantitative Insights into Microbial Ecology (QIIME).

Study of aeromycoflora in indoor and outdoor environment of national library, kolkata

Abstract: We aimed at the systematic evaluation of air-borne fungal flora of the National Library, Kolkata for a period of three months beginning from February to April, 2010 to determine their identification, concentration and diversity in both indoor and outdoor environment to understand the cumulative aeromycoflora composition. The period of study was the post winter period followed by pre-summer months that was mild to moderate warm and low to high humid condition with temperature and humidity ranges of 17.0-38.2°C and 26-92% respectively. Air sample was collected with interval of two weeks by means of gravitational settling method using petri dishes with Malt Extract Agar (MEA) media. Fungal colonies that formed after 3-5 days incubation period at 25-28°C were identified on the basis of micro and macro morphological characteristics and finally percentage contributions of individual fungal species were calculated. A total of 21 types of fungal spores were identified from indoor environment with 5 sterile hyphae and 13 unidentified spore types. In case of outdoor environment, total number of spore types encountered was 19 along with 12 sterile hyphae and 6 miscellaneous types were recorded under unidentified spore type. The prevailing presence of Aspergillus niger, Alternaria tenuissima, Cladosporium herbarum and Penicillium sp. were accounted for a high percentage in indoor environment whereas outdoor environment showed clear dominance of Alternaria alternata, Asperillus niger, Alternaria tenussima, Cladosporium herbarum, Cladosporium cladosporioides, Curvularia lunata and Fusarium oxysporum. Among all the fungal spore types the taxonomic group Deuteromycotina showed dominance in total spore contribution. Biomonitoring of aeromycoflora is a key to open the information of sensitivity towards bioaerosol in this atmosphere and our findings may be useful with regard to the investigation of corrective measures to save the library materials from fungal damage and diagnosis and prophylaxis of allergic diseases resulting from aeromycoflora composition of this environment.