Author:
S Debnath1,2*
Author address:
1Rural Agriculture, Mani Trust, Kalimpong, India
2Microbiology Dept, Centre for Study on Environmental Microbiology, Guwahati, India
Full conference title:
10th Advances Against Aspergillosis and Mucormycosis
Date: 2 February 2022
Abstract:
Purpose:
Species under Mucoreles are mostly air borne and also found in soil, water and decomposed plant materials, compost and food items including breads, rice, dry foods items. Very few studies available in the literature on the impact of soil fungistasis on growth of mucorales.
Rhizopus stolonifer (Ehrenb:Fr) Vuill was isolated from outdoor air during the period of three year survey of aeromycoflora over residential apartment (Ananda Niketan, Anandanagar Adabari) in metropolitan area of Guwahati, Assam, India. The present work investigates the influence of sterile (autoclaved) and unsterile soil (natural soil) on fate and germination behaviour of spores of Rhizopus stolonifer.
Methods:
Site of experiment: The study was carried out at rooftop of three storied residential apartment, Ananda Niketan, Anandanagar, Guwahati, Assam (Lat 26.1065° N, Lon 91.5860° E). Air mycoflora was studied by settle plate method as per Turner, 1966. The fungus was isolated and morphologically identified as per Zheng et al (2007).
Source of Soil samples: Soil samples were collected from 13 different sections from a tea farm along with data on soil carbon, pH, potash and sulphur content.
Germination test: Germination studies on soil was carried out as per agar block method (Dobb and Hinosan 1953).A spore is said to be germinated if the germtube exceeds half the diameter of normal spore(APS 1934)
Results:
1. Unautoclaved soil reduced a mean germination rate of R. stolonifer 61% while autoclaved soil cause 28% inhibition (r=+0.68).The estimated germ tube growth rate for autoclaved and non autoclaved soil were 166µm/hr and 66 µm/hr respectively.
2. There were wide variation of germination among 13 different soil samples which may be attributed to variation in soil carbon, pH, potash and sulphur content.
3. Unautoclaved soil caused significant abnormality i.e. zigzag growth, swelling of hyphae and excessive coiling, excessive growth etc. in germ tube growth and development.
4. A few spores in unautoclaved soil transformed in to a spherical body almost double the spore size with dark dense protoplasmic material inside. The germ tube get fade away and probably remained inactive. This event takes about 72 hours.
Conclusion:
Germination of air borne R. stolonifer was suppressed significantly induced growth abnormalities and inactivates fungal propogulae by agricultural soil. Soil pH, carbon
content has influenced germination in autoclaved and unautoclaved soil. Further studies on origin and elucidation of chemodiversity in soil due to secondary metabolites of microbes, preventing growth of human pathogenic fungus is under priority areas of research.
Abstract Number: 40
Conference Year: 2022
Link to conference website: https://aaam2022.org/
URL Conference abstract: