ABSTRACT
The Eastern Ghats are a discontinuous hill range in peninsular India and stretch from the Mahanandi Basin in the north to Nilagiri Hills in the south, covering a distance of 1700 km and spreading over 75,000 km, with an average elevation of the mountain range of 600 m falling between 13°30’–19°07’ N and 77°28’–84°45’ E. The microbial populations are not explored in the Eastern Ghats for xylanases. In the present study, soil samples from the Eastern Ghats of Andhra Pradesh at different places with coverage of shrubs to large trees were collected and analyzed for soil properties and microbial populations on different media at two different temperatures 30 °C and 37 °C. The media used for the determination of the population of fungi, bacteria, and actinomycetes were Rose Bengal agar medium (RBA)/ Czapekdox agar medium (CZA), mineral salts agar medium (MSM), and starch-casein agar medium (SCAM), respectively. The carbon source of all the media was amended with 0.1% birch wood xylan or 10 g/L xylose, and the pH was adjusted to 5.0 for fungi and 7.0 for bacteria and actinomycetes. The microbial populations were expressed in CFU/g of dry weight soil. Xylose-utilizing bacterial populations ranged from 4 × 105 to 54 ×105, 8 × 105 to 52 × 105 in forest soils of the Eastern Ghats at 30 °C and 37 °C, whereas the xylan-utilizing bacterial population occurred at 2 × 104 to 45 × 104, 5 × 104 to 39 × 104 in the same forest soils at 30 °C and 37 °C, respectively. Xylose-utilizing actinomycetes populations at 2 × 104 to 14 × 104, 3 × 104 to 14 × 104 were recorded as against the xylan-utilizing actinomycetes population density of 2 × 103 to 11 × 103, 2 × 103 to 11 × 103 at 30 °C and 37 °C in the forest soil samples, respectively. Xylose-utilizing fungal populations at a density of 12 × 103 to 96 × 104, 4 × 103 to 35 × 104 were observed as against xylan-utilizing fungal populations at 12 × 103 to 94 × 104, 5 × 103 to 27 × 104 at 30 °C and 37 °C in the forest soils, respectively. Some of the fungal cultures isolated from forest soil samples exhibited xylanase activity within a range of 400 to 4000 U/ml and has the potential for harnessing several applications in paper, pulping, and bioethanol industry.
