Production of phenolics under abiotic stress by Pisolithus tinctorius PT1 obtained from iron ore mine

Abstract

Pisolithus sp. was isolated from ectomycorrhizal association with Acacia mangium growing in mining affected forest area along the west coast of India. The in vitro growth response and phenolics production by the isolate was checked using mineral medium for various edaphic factors prevailing in rejects of iron ore mines. Phosphatecitrate buffer (0.047 M) was found suitable for maintaining the pH of the medium. The isolate survived at 10 and 42 degrees C. Interestingly, the isolate showed growth in the presence of 10,000 ppm Mn and appeared to be the most Mn-tolerant. The isolate preferred ferric form of iron over ferrous. The optima of all the variables for phenolics production were found at higher values than that required for the growth of isolate, significantly revealing the enhanced elaboration of phenolics at stress conditions. Maximum yields of phenolics obtained were 149.91, 164.07 and 61.34 mu g/20ml with 1.5 percent NaCl, 37 degrees C and 5 percent PEG, respectively. The wide tolerance and elaboration of phenolics by Pisolithus sp. to various edaphic factors present in mine rejects could be responsible for its stable existence on such disturbed site. This suggests its possible ecological application and industrial utilization.