A number of commercially available culture media are in use for the isolation, identification and study of fungi for the last so many years namely potato dextrose agar (PDA). However the high cost of these culture media has been proved to be a hindrance in its accessibility, particularly in developing and underdeveloped countries for introducing Microbiology at undergraduate and graduate level studies. Keeping in view this particular aspect, there is a strong justification to develop such culture media which can serve as substitute for the conventional medium (CM) and can be prepared from simple, round the year available components, hence rendering them cost effective too. The use of natural extracts to be used in culture media can be one of the simplest yet very effective approach in this regard. The present study is aimed to grow Aspergillus niger on a variety of culture media prepared with various plant extracts obtained from bougainvillea stem, coconut, date and neem bark and neem leaves. These extracts were used either without supplementation (WOS) or supplemented with carbon (sugar cane bagasse extract) and nitrogen (yeast extract) sources alongwith the mineral salt solution (MSS) to prepare the culture media. The results obtained were recorded in terms of measurement of radial growth which was then compared with the results obtained on CM. It was observed that on the media WOS the growth was measured between 10-11mm with a maximum extension of 85 mm after 12 days, while the media with supplementation showed growth between 12-13 mm with increase in diameter up to 90 mm in 12 days. On PDA the initial growth was found to be 14 mm which attained a maximum diameter of 85 mm after 12 days. The media WOS showed late and less sporulation, while the media supplemented with carbon and nitrogen sources showed relatively better sporulation. The sporulation and rate of growth were enhanced in the media, supplemented with MSS in addition to carbon and nitrogen sources. The spore count on the media WOS, with supplementation and CM was found to be 105, 2-2.3 x 106 and 2.5 x 106 respectively. The results revealed that the spore count of Aspergillus niger in supplemented media is comparable with that of CM. In further research, these media have also been used to evaluate their efficacy to support the growth of other fungal species.
Full conference title:
- ASM 115th (2015)