Aims:  This study evaluates the behaviour in spiked sludge of a pathogenic bacteria, Listeria monocytogenes, by cultural and molecular techniques, and compares its survival with the one of a faecal indicator, Enterococcus faecium. Methods and Results:  Listeria monocytogenes strain Scott A and E. faeciumT were followed for 17 days after inoculation in sludge. Kinetics of survival depended on the bacteria and on the technique used [most probable number method, direct plate count or real‐time quantitative PCR (qPCR)]. The concentration of L. monocytogenes decreased rapidly regardless of the technique, but the decrease was much more dramatic with culture techniques than with qPCR. On the contrary, the concentrations of culturable E. faeciumT were stable. Conclusions:  The results suggest that the cells of L. monocytogenes strain Scott A might have entered a viable, but nonculturable (VBNC) status, whereas cells of the indicator bacteria, E. faeciumT, maintained themselves better and stayed culturable. Significance and Impact of the Study:  The difference of survival kinetics in the sludge of a faecal indicator (E. faecium) and a pathogenic bacterium (L. monocytogenes) may be linked to the fact that they either enter or do not enter into a VBNC status.

Heavy metals adversely influence microorganisms, affecting their growth, abundance, genetic diversity, nodulation ability and efficacy. The aim of this study was to isolate and characterize free-leaving Rhizobium from soil which were artificially polluted with Cu (100, 250, and 500 mg kg-1 soil), Zn (300, 700, and 1500 mg kg-1 soil) and Pb (50, 250, and 1000 mg kg-1 soil), but also with a mixture of all these metals, and cultivated with red clover (Trifolium pratense L.), and to compare them with bacteria isolated from similar type of soil, but unpolluted. Rhizobia from soil were isolated on YMA medium with or without bromothymol blue (0.00125%) as a pH-change indicator and the morpho-physiological characteristics of the colonies were examined. The number of Rhizobium was estimated using the most probable number method. Compared to the control, a decrease of rhizobia number and an increase of the metal concentration were observed. Several decameric primers (Operon Technology type) were used and a reduced polymorphism among isolated bacteria was observed. Moreover, significant differences were observed among these strains and the collection strains used as reference. Also, when primers nodCF/nodCI for detection of nod genes were used, several amplicons were obtained, different from the results obtained with similar strains isolated from unpolluted soil. These results suggest that the survival „price” of the Rhizobium in such polluted area was the alteration of some genes, including those involved in symbiosis and, probably, in nitrogen fixation.

Burning crop residues is frequently used by Romanian land users to clean agricultural fields after crop harvest for ease in postharvest soil tillage. Huge amounts of crop residues biomass, on very large areas, were burned in Romania in the last twenty years, as compared to other countries. There are several reasons (e.g. the lack of equipment to gather the crop residues and to transport and store them, the diminishing of the livestock after 1990, the absence of other alternatives, especially in the 1990s, but also the lack of information regarding the good practices) that are evocated to support the use of this method. However, this method is not a sustainable one since it can cause many environmental damages, especially related to soil properties (physical, chemical and biological), greenhouse gas emission and crop yields. Contrary to the above stated, crop residues' addition to the soil may restore damaged soil structure, improve aggregate stability, soil water retention, soil fertility, increase total organic carbon (TOC) and total nitrogen (TN) etc. The purpose of this paper is to make a multicriteria analyze of the effects of crop residue management on the soil, agricultural productivity and environment. At the same time, the use of crop residues biomass as a source of energy is presented as an alternative, given its potential ability to offset fossil fuels and reduce CO2 emissions.

The interest in biofuels is growing globally and the demand for bioenergy throughout the European Union will expand considerably in the following years. Numerous studies have shown that energy resulted from green plants has much to offer, as it is renewable and largely carbon-neutral compared with fossil fuel combustion. However, this is an increasingly controversial issue due to its strong impact on economy, environment and land use. Romania is one of the European Union Member States with a large biofuel production resources, owing to its high land agricultural area and good conditions for cereal and oilseed growth. There has been an increasing tendency to grow biofuels in the Romanian cultivated areas over the last decades; however, it is difficult to know if biofuel production is sustainable in this part of Europe and what impact may have unsustainable production since there is no or scientific research on this topic. The aim of this paper is to present the dynamics of biofuel crops (biodiesel) areas in Romania over the last decade, and to introduce a short review on the possible impacts on the environment, greenhouse gas emissions (GES) and land use in order to defend the need of information for our particular situation.

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