Penicillium aculeatum PDR-4 and Trichoderma sp PDR-16 promote phytoremediation of mine tailing soil and bioenergy production with sorghum-sudangrass

Fungi can facilitate phytoremediation of mine tailing soil containing heavy metal(loid)s (HMs). Penicillium aculeatum PDR-4 and Trichoderma sp. PDR-16, isolated from the rhizosphere of Pinus koraiensis in mine tailing soil, exhibited high HM tolerance and plant growth-promoting characteristics. The isolates increased available P in a 1:1 (w/w) mixture of soil and liquid media by 14-43% and the bioavailability of As, Cu, Pb and Zn was also increased. Both isolates exhibited phosphatase, phytase and siderophore activity. ACC deaminase activity was greater in PDR-16 than in PDR-4; IAA was produced by PDR-4 but not by PDR-16. Sorghum-sudangrass (Sorghum bicolor x sudanense) produced 37-95% more aboveground dry biomass and contained 74-128% more chlorophyll in inoculated soil. In soil inoculated with both isolates, HM concentrations increased in roots by 109% (As), 39% (Cu), 50% (Pb) and 38% (Zn), and in shoots by 72% (As), 69% (Pb) and 82% (Zn) compared to those of control plants (Cu concentration did not increase in shoots). HM bioavailability and available soil P, as well as plant biomass, chlorophyll content and plant As, Pb and Zn concentrations were highest in soil inoculated with both fungi. Results suggest that inoculating soil with P. aculeatum PDR-4 and Trichoderma sp. PDR-16 will be beneficial for phytoremediation and production of sorghum-sudangrass as a bioenergy crop in HM-contaminated soils. (C) 2014 Elsevier B. V. All rights reserved.