Short Communication: Metabolites of Albizia inhibit in vitro growth of phosphate solubilizing microbial consortia isolated from tea garden soil of Darjeeling hills, India

Abstract

Phosphate solubilizing microorganisms (PSM) play a crucial role in maintaining the nutritional status and fertility of the soil. PSMs help in solubilizing the metallic phosphate salts of soil into available phosphate anions for easy uptake by plants. However, this beneficial group of microorganisms also face different challenges for survival from its immediate surroundings. This study was carried out to assess the effect of shade tree litters on the PSM consortia isolated from different tea garden soils of Darjeeling hills, since shade trees are an integral part of tea plantations. Albizia odoratissima, Albizia chinensis and Albizia procera, widely used in tea gardens as shade trees were selected. GC-MS analysis was carried out to detect the metabolites produced by the litters. Twenty-three compounds exhibiting antimicrobial activities were detected. Major peak was found in A. odoratissima, followed by A. chinensis and least in A. procera. Compounds like 1-heptanol, 2-propyl-, neophytadiene, phytol and squalene were common in all three extracts and are considered to provided antimicrobial activity to Albizia. A proportional relation has been observed between magnitude of inhibition zones and peak area percentage in Albizia spp. PSM isolates from shade tree gardens were observed to be more tolerant toward the leaf extracts.