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Second-generation biofuel crop miscanthus is one of the most promising plants tested for phytomanagement of contaminated sites. In this preliminary pot case study, the most used hybrid Miscanthus x giganteus was cultivated in three different real contaminated soils: agricultural soil contaminated with Cd, post-military soil slightly contaminated with Zn, Pb and Cd, and soil contaminated by petroleum industry with metals and hydrocarbons. The stress response of plants and soil microbial communities was monitored to receive data that are important for successful phytomanagement application. With metals only, the plant grew well, and chlorophyll fluorescence measurement proved their good vitality. Changes in leaf anatomy (leaf thickness and sclerenchyma cells area) were additionally determined in post-military soil compared to agricultural. On the contrary, in petroleum-contaminated soil, the biomass yield was too reduced and also physiological parameters were significantly decreased. The response of microbial communities also differed. In agricultural soil, no microbial stress was determined. In post-military soil, it became reduced during the experiment, and in petroleum contamination, it increased year-on-year. It could be concluded that miscanthus is suitable for cultivation in metals contaminated soils with potential for microbial communities support, but in soil contaminated by the petroleum industry, its application did not seem meaningful.

Soil is a key part of a biotope and microorganisms are dominant components contributing to soil functions. Conversely, established methods for valuation of biotopes according to Natura 2000 rely predominantly on the communities living on the surface. Here, we aimed to assess soil microbial biomass and community structure on five localities with range of biotope values by means of phospholipid fatty acid (PLFA) profiling. PLFA figures were affected both by sampling season (spring vs. autumn) and locality. In spring, the living microbial biomass (estimated by PLFAtot) exhibited poor correlation to biotope values. These were, on the contrary, correlated to trans/cis PLFA, an indicator of microbial stress, (i.e., lower stress in higher-rated biotopes), and fungal/bacterial PLFA (i.e., higher-rated biotopes contained more fungi). The attempt to model biotope values from microbial characteristics explained a maximum of ~50% of the variability; the best predictors were the trans/cis stress indicator, percentage of actinobacterial PLFA, and ratio of PLFA of Gram-positive to Gram-negative bacteria. These results show that soil microbial characteristics present partly new information and indicate the need to amend the procedures of biotope assessment. Soil PLFA profiling could serve as suitable methods for this purpose.

At present, there is great demand for new resistant and metabolically active strains of biodegrading bacteria capable of degrading high concentrations of petroleum pollutants. In this study, we undertook a series of pot-based biodegradation experiments on soil from a petroleum refinery lagoon heavily polluted with aliphatic hydrocarbons (81.6 &plusmn, 2.5 g&middot, kg&minus, 1 dry weight) and metals. Periodical bioaugmentation with either a mixture of isolated degraders identified as Bacillus sp. and Ochrobactrum sp. or biostimulation with nutrient medium, singly or in combination, did not produce any significant decrease in hydrocarbons, even after 455 days. Inoculation with Gordonia rubripertincta CWB2 and Rhodococcus erythropolis S43 in iron-limited media, however, resulted in a significant decrease in hydrocarbons 45 days after bioaugmentation. These actinobacterial strains, therefore, show significant potential for bioremediation of such highly polluted soils.

In the Protected Landscape Area “Labské pískovce” (Czech Republic), there are many sandstone caves accessible by permission only and where climbing equipment is commonly required. The tradition of visiting the caves dates back to turn of the 19th and 20th centuries, and visitors traditionally record their visits in log-books. We have gathered attendance data from 12 caves from log-books and via survey (2-year form collection period). The attendance varied from less than 10 to ~650 visitors annually. Signs of inadequate behavior of visitors were observed, especially waste disposal and smoking in the caves. Sediment step-compression increased significantly the ratios of fungi/bacteria and gram-positive to gram-negative (G+/G−) phospholipid fatty acids (PLFA) as well as PLFA of actinobacteria and activities of sediment phosphatases, glucosidases, and peroxidases. The number of visitors was correlated positively with the G+/G− ratio and sediment nutrients but negatively with sediment moisture and the activity of peroxidases. The results indicate a significant effect of attendance on sediment microbial communities, most likely caused by the import of nutrients into caves. Hence, reconsideration of the cave attendance policy is recommended.