Six decades of Aerobiology research in NE India
- Part 2 -

Dr N Irabanta Singh *

Center of Advanced Study in Life Science at Manipur University :: Pix - Bunti Phurailatpam

Aerobiology research during 1988 to 1997 (Fourth decade)

Aeropalynology and allergic human diseases were more concentrated on airborne pollen grains. It was recognized that weed pollen causes allergic rhinitis or asthma followed by grasses and trees. Eighty pollen types wee identified from the air of Kakching by employing Durham type aeroscope (modified). Herbs, shrubs and trees contributed 52.9%, 17.5% and 27.7% of the total pollen types categorised. Day to day, diurnal, and seasonal variations were recorded to estimate the quantitative incidence of airborne pollen grains (Singh & Singh, 1992).

The main aeroallergens were Cynodon, Digitaria, Eleosine, Oryzae, Panicum, Sefaria, Imperata, Zea, Poaceae, Alnus, Callislemon, Artemesia, Eucalyplus, Carica, Syzygium, Azadirachta, Coriandrum, Morus, Xanthium, Albizzia, Amaranthus, Ageratun, Lantana, Mangifera, Riccinus, Cassia, Rumex, Bauhinia, Brassica, Chenopodium and Acacia (Singh, 1992).

Aeromycology and allergic human diseases were concentrated on airborne fungal spores; From allergic point of view, Chaetomium globosum, Cladosporium cladosporiodes, Heminthosporium oryzae, Aspergillus niger, Alternaria alternata, Stemphyllum sp., Penicillium notatum, Nigrospora sphaerica, Epicocum sp. , Curvularia lunata, Torula herbarium, Humicola nigricans, Pyricularia oryzae, Mucor sp. Fusarium oxysporium were known to be significant in causing Type - I allergy (Singh, 1992).

Aerobiology and Biopollution of Extramural Environment

The influence of paddy threshing on biopollution confirmed the occurrence of Cladosporium, Aspergilli-Penicilli and smut spores more than half of the total number of spores caught. Thus, threshing operation of paddy elevate biopollutants in the air and may induce respiratory diseases to the workers (Singh and Singh, 1995).

Indoor airspora of Pleurotus growing room during spawn running, fruiting and post harvesting stages by employing rotorod exposure method revealed high concentration of Pleurotus spores. This study suggests introduction of spore less strains of Pleurotus for cultivation as airborne spores of Pleurotus are inhaled by the mushroom growers which leads to respiratory diseases (Singh et. al., 1993).

Aerobiology and Ecology of Plantation Sites

The fungal air spora of Fig (Ficus hispida L.) Plantation sites in Imphal district by employing gravity slide exposure in Durham type aeroscope method revealed 16 fungal spore types. The most important type are -Alternaria, Chaetomium, Erysiphi, Tetroploa, etc. (Singh & Devi, 1988). In another study, by exposing nutrient petriplates four types of bacteria (Phytococus aurcus, S. epidermis, S. Pryregenes and S. ftacalis) were isolated predominantly over the air of Oak (Quercus serrata L.) plantation site in Senapati district, Manipur (Singh et. al., 1993).

Aerobiology and Bacterial diseases of Oak Tasar Silkworm

Air monitoring of silk worm (Antheraea proylei) larvae rearing room for air borne bacteria was conducted for 13 by exposing nutrient petriplates. A total of 10914 CFU were recorded from 156 air samplings. Out of these, 9582 CFU were allotted to 18 species belonging to 14 genera. Important bacterial isolates were Bacillus sp., Stephytococcus sp., Arthrobactor sp., Coryneform sp.. Pseudomonas sp., Escherichia sp., Proteus etc. Highest bacterial count was recorded during July to September with maximum range of temperature and relative humidity of 26-30oC and 9~ percent respectively.

Out of 15 air borne bacterial isolates for testing pathogenecity, 12 isolates. such as Micrococcus sp., Staphylococcus citreus, Streptococcus faecalis, Coryneform sp., Bacillus sp., B. thuringiensis, B. cereus var. mycoides, Pseudomonas dimuneta, 8rEscherichia coli, Serratia sp., Proteus sp. etc. were found pathogenic to A. proylei larvae with varying degree of pathogene city (Singh and Chandra, 1994).

Aerophycology and soil fertility

Few studies on airborne algae were carried out at Guwahati (Sarma and Barma, 1982) and Imphal by exposing nutrient petriplates in Durham type aeroscope (Singh, 1997). Important algal forms (BGA and GA) were Microcystis, Oscillaria, Nostoc, Anabaena, Plectonama, Lyngbya, Phormidium, Chlorococcum, Chlorella, Chlamydomonas, Oedognium, Spirogya, etc.

Airborne BGA which are washed down by raindrops ITom the air to the rice fields might also serve as a potential nitrogen fixer ITom the atmosphere for increasing soil fertility. The air samplers used during this decade were nutrient petriplate exposure method Durham type aeroscopes and rotorod air sampler.

Aerobiology research during 1998-2007 (Fifth Decade)

Aeromycology and biopollution of Intramural working environment

Analysis of indoor fungal airspora in the working environment of bakery in Imphal by employing rotorod air sampler revealed Penicilliium, Aspergillus, Mucor, etc. as dominant biopollutions (Singh and Devi, 1998).

Monitoring indoor airspora of rice mill in Bishenpur district, Manipur by employing Andersen air sampler revealed 44 fungal types. Dueteromycotina dominating 86% the total airspora followed by Phytomycotina.

Fluctuation of fungal airspora concentration was correlated with meteorological factors in addition to other substrates and ambient air movement (Singh and Singh, 2001).

Further, monitoring of indoor airspora of poultry in the same district by employing Andersen air sampler revealed Deuteromycotina dominating 88.9% of the total airspora followed by Phycomycotina (11.6%) (Singh and Singh, 2001).

Aeromycology and fruit spoilage

Aeromycoflora studies over fruit market in Greater Guwahati by employing nutrient petriplates exposure method revealed Alternaria alternata, Aspergillus niger, Botryodiplodia theobromae, Colleotrichum musae, Fusarium moniliform, Penicillium citrinum etc. from three verities of banana. The study also revealed 16 to 121% of banana were affected due to fungal infection (Sarma, 1999).

Aeromycology and crop diseases

A study of airspora over potato (Solanum tuberasium L.) crop fields in Imphal area by employing rotorod air sampler revealed 35 fungal types. Cladosporium was the most dominant fungal type whereas the spores of Phytophthora infestanes and Alternatia solani were also recorded but less in number. The study found important pathogenic fungal types as airborne (Singh and Devi, 2007).

Aeropalynology and human allergenic significance

Outdoor pollen airspora of Thoubal district, Manipur was carried out by using Burkard Personal Slide Sampler. Fourteen pollen morphotypes were identified. The common types were Acacia, Artemesia, Eucalyptus, Poaceae, Ricinus, Solanum, etc. (Sharma, Romesh and Singh, 1980). Aeropalynological survey in central Guwahati by using rotorod air sampler revealed 74 pollen types. The pollen of poaceae type ranked first followed by Amaranthus – chenopode type and Asteraceae.

It was observed that anamophelious pollen ranked first in order of dominance. Herbaceous pollen showed maximum incidence. Among the pollen granins Amaranthus – chenopode type, Asteraceae, Poaceae, Azadichta indica, Mangifera indica, Drypetes roxburghii, Eucalyptus and Terminatia cuneala are known allegenically significant (Devi & Sarma, 2007).

The air samplers used during this decade include nutrient plate exposure method, Rotorod air sampler, Andersen air sampler and Burkard air sampler.

To be continued...