Studies on the effect of salinity on some aspergilli of usar and fertile soil to assess possible ecological specialization

Abstract

A comparative salt (Viz., Sodium Sulphate, Sodium Chloride, Magnesium Sulphate) tolerance tests conducted in relation to usar (=Alkaline Soil) and fertile soil Aspergilli, revealed that over all, usar isolates showed more growth and tolerance on increased salt concentrations than their fertile counterparts. Among the three salts put to test, sodium chloride has shown pronounced toxic or inhibitory effect on Aspergilli at higher concentrations. The maximum tolerance has been exhibited by Aspergillus fumigatus as it grew up to twenty four percent concentration, however none of the other Aspergilli including both usar and fertile type showed such type of sustainability. Of the salts tested, Magnesium sulphate seemed to be the salt of more utility to both types of isolates as exhibited by their growth at different concentration levels and further all the Aspergilli tested showed more physical growth at different concentrations of this salt in comparison to other two salts tested. Salinity also affected the sporulation of different Aspergilli. Visual observations of culture of different Aspergilli revealed that usar islotaes comparatively showed more tolerance even in sporulation. Usar isolates showed the alkaliphilic nature by showing more salt tolerance and can be recognized as Haloalkaliphiles as they have attained ecological specialization to quite an extent.