One of the most studied approaches in solubilization of insoluble phosphates is the biological treatment of rock phosphates. In recent years, various techniques for rock phosphate solubilization have been proposed, with increasing emphasis on application of P-solubilizing microorganisms. The P-solubilizing activity is determined by the microbial biochemical ability to produce and release metabolites with metal-chelating functions. In a number of studies, we have shown that agro-industrial wastes can be efficiently used as substrates in solubilization of phosphate rocks. These processes were carried out employing various technologies including solid-state and submerged fermentations including immobilized cells. The review paper deals critically with several novel trends in exploring various properties of the above microbial/agro-wastes/rock phosphate systems. The major idea is to describe how a single P-solubilizing microorganism manifests wide range of metabolic abilities in different environments. In fermentation conditions, P-solubilizing microorganisms were found to produce various enzymes, siderophores, and plant hormones. Further introduction of the resulting biotechnological products into soil-plant systems resulted in significantly higher plant growth, enhanced soil properties, and biological (including biocontrol) activity. Application of these bio-products in bioremediation of disturbed (heavy metal contaminated and desertified) soils is based on another important part of their multifunctional properties.

The quantity of thiocyanate ion in vegetables has been determined due to its relationship with endemic goiter. The technique is based on the use of gas chromatography with electron capture detection (ECD), which provides good sensitivities.

Elevated concentrations of heavy metals in soil from anthropogenic sources or mining activities pose long-term environmental risk. The deteriorated physical and biological soil characteristics need to be improved to establish a vegetation cover. An interesting approach applied in in situ remediation of contaminated soil includes a variety of phosphate amendments. In addition, it is well known that the bioavailability of heavy metals in soil is affected by the presence of organic matter.The aim of this work was to test the effectiveness of a biotechnological product on plant growth in Zn-contaminated soil.Phanerochaete chrysosporium was cultivated on agro-industrial wastes (sugar beet wastes, SB, and dry olive wastes, DOW) supplemented or not with animal bone char (ABC). The resulting end biomaterials containing mineralized (58-62%) organic matter, soluble P (21-415 mg/l) and fungal mycelium were introduced into typical Mediterranean soil contaminated with Zn at 100 and 400 mg/kg. In soil contaminated with the higher Zn concentration, ABC alone reduced plant Zn uptake by 32 and 15% in non-and mycorrhizal plants, respectively. Zn uptake in non-and mycorrhizal plants was lower in all treatments enriched with biotreated SB. Under the same conditions, the lowest Zn uptake rate of 306 g per pot was found in shoots of mycorrhizal plants grown in treatments with microbially treated agro-industrial wastes and ABC compared to 1158 mg/pot in the non-mycorrhizal control. The latter bio-treatment also proved highly effective in increasing shoot dry matter and P uptake.Thus, the biotechnological product that includes microbially treated organic matter, partially solubilized ABC and fungal mycelium offers a low-cost, environmentally mild alternative for remediation of metal-polluted soils. Another advantage of the proposed biotechnological scheme concerns the potential use of industrial bone meal ashes and bone char as novel and efficient sources of phosphate. One of the most important characteristics of heat-treated bone meal is their low metal content while traditionally used in the P-fertilizer producing industry rock phosphates contain cadmium, lead, cooper, arsenic, and other heavy metals.Salt tolerance in plants is a complex phenomenon involving morphological, physiological and biochemical processes. The accumulation of compatible solutes has proved to be an essential mechanism of salt tolerance. In many regions, agricultural soils display increasing levels of salt ions with NaCl being usually the predominant salt. Increased NaCl salinity decreases vegetative growth as well as the rate of photosynthesis and usually leads to ionic disturbance of plant cells. In this study the effect of NaCl on Ceratonia siliqua (carob) plantlets cultured in vitro was analyzed as well as the levels of proline and several ions in plants under stress saline (NaCl) conditions. This tree species is cultured in regions of the Mediterranean basin. In Portugal, carob grows mainly in the south (Algarve), near the coast, where the pods are used as f...