Testing of Penicillium sp. R7.5 and Aspergillus niger NK fungus activity on media to enhance the growth of rice plants in saline soil

Abstract

Subowo YB. 2015. Testing activity of Penicillium sp. R7.5 and Aspergillus niger NK fungus on media to support the growth of rice plants in saline soil. Pros Sem Nas Masy Biodiv Indon 1: 1136-1141. The research was executed on the examination of the fungus Penicillium sp. R7.5 and Aspergillus niger NK activity on a medium having sea water. High soil salinity and alkaline condition cause low fertility of agricultural soil at the beach and tidal area. Soil fertility can be improved by the application of biological fertilizer containing salt-tolerant microbes. Penicillium sp. R7.5 and Aspergillus niger NK were isolated from the coastal soil so that both fungi were expected to be able to grow well in saline condition. The purpose of this study was to observe the activity of both fungi in saline conditions. Growth media with 5 different concentrations of sea water such as 0, 25, 50, 75 and 100% was used in the experiment. The considered parameters were the growth rate of the fungi, fungus activity of lignin degradation, fungus ability to dissolve phosphate compound and produce IAA. The result showed that Penicillium sp. R7.5 and Aspergillus niger NK were able to grow on media containing 100% seawater. Both fungi were also able to degrade lignin and cellulose where Penicillium sp. R7.5 showed higher activity (28.5 ppm/hour) than Aspergillus niger (13.65 ppm/hour). Both fungi were able to dissolve phosphate compounds in medium containing 100% seawater where Penicillium sp. R7.5 showed higher activity (2.17 ppm) after 3 days incubation. Both fungi were able to produce IAA though Penicillium sp. R7.5 showed higher capacity (7.14 ppm) at growth medium containing 25% sea water. Both fungi were able to increase the weight of the rice plant biomass as much as 188% in soil media containing 0.5% salt.