Biomedical subjects

I García-Romera

Publications and source records attributed to I García-Romera.

4 recordsLinked to original sources

PubMed2006

Reusing ethyl acetate and aqueous exhausted fractions of dry olive mill residue by saprobe fungi.

Some saprobe fungi (Phlebia radiata, Trametes versicolor, Coriolopsis rigida, Pycnoporus cinnabarinus, Fomes sclerodermus or Pleurotus pulmonarius) were able to bioconvert the ethyl acetate fraction (DEAF) and the corresponding aqueous exhausted fraction (EAF) of dry olive mill residue (DOR), reducing their phytotoxicity on Lepidium sativum seeds. Large amount of hydroxytyrosol together with other eight monomeric phenols were found in the native DEAF fraction, which represents a good source of antioxidants. P. radiata, T. versicolor and F. sclerodermus caused an effective phytotoxicity reduction of EAF in the concentration range of 25-3 gl(-1). In particular, in the range between 12.5 and 3 gl(-1), the EAF samples inoculated with P. radiata and F. sclerodermus surprisingly stimulated the germinability of L. sativum, suggesting their use as a potential biofertilizer. This is the first report which showed the bioconversion of the above fractions in shorter time with respect to the previous findings concerning DOR. The possible implications of laccase in the decrease of DEAF and EAF phytotoxicity was also discussed.

Acetates↗

PubMed2005

Bioconversion of olive-mill dry residue by Fusarium lateritium and subsequent impact on its phytotoxicity.

The present study investigated the ability of the non-pathogenic fungus Fusarium lateritium to either degrade or modify aromatic substances in olive-mill dry residue (DOR) and to reduce its phytotoxicity. The 80% reduction of ethylacetate extractable phenols in DOR colonized by the fungus for 20 weeks appeared to be due to polymerization reactions of phenol molecules as suggested by mass-balance ultrafiltration and size-exclusion chromatography experiments. Several lignin-modifying oxidases, including laccase, Mn-peroxidase and Mn-inhibited peroxidase were detected in F. lateritium solid-state cultures. Tests performed with tomato seedlings in soils containing 6% (w/w) sterilized non-inoculated DOR showed that the waste was highly phytotoxic. By contract, F. lateritium growth on DOR for 20 weeks led to a complete removal of the waste toxicity and to a higher shoot dry weight of tomato plants than that obtained in the absence of DOR.

Agriculture↗

PubMed2003

Improvement by soil yeasts of arbuscular mycorrhizal symbiosis of soybean (Glycine max) colonized by Glomus mosseae.

The effects of the soil yeasts Rhodotorula mucilaginosa, Cryptococcus laurentii and Saccharomyces kunashirensis on the arbuscular mycorrhizal (AM) fungus Glomus mosseae (BEG 12) was studied in vitro and in greenhouse trials. The presence of yeasts or their soluble and volatile exudates stimulated the percentage spore germination and hyphal growth of G. mosseae. Percentage root length colonized by G. mosseae and plant dry matter of soybean (Glycine maxL. Merill) were increased only when the soil yeasts were inoculated prior to the AM fungus. Higher beneficial effects on AM colonization and plant dry matter were found when the soil yeasts were inoculated as an aqueous solution rather than as a thin agar slice. Although soluble and volatile exudates of yeasts benefited the AM symbiosis, their modes of action were different.

Cryptococcus↗

PubMed2003

Contribution of hydrolytic enzymes produced by saprophytic fungi to the decrease in plant toxicity caused by water-soluble substances in olive mill dry residue.

We studied the influence of saprophytic fungi on the toxic effect that the water-soluble substances in dry residues from olive (ADOR) have on the growth of plants. All saprophytic fungi were able to decrease the phytotoxicity of ADOR, although the toxicity of this residue did not decrease in the same way. Penicillium chrysogenum was able to reduce the toxicity of ADOR when this residue was applied at the highest dose of 15%. Fusarium lateritum, F. graminearum and Mucor racemosus were able to reduce the toxicity of ADOR when this residue was applied at the intermediate doses. However, F. oxysporum decreased the phytotoxicity of ADOR only when the residue was applied at the lowest dose of 2.5%. All saprophytic fungi tested produce endoglucanase, endopolymetylgalacturonase and endoxiloglucanase when grown in the presence of ADOR. A close relationship was found between the decrease in the phytotoxicity of ADOR and the amount of hydrolytic enzymes produced by the saprophytic fungi. These results shows that hydrolytic enzymes can be important in the degradation of phytotoxic substances present in olive mill dry residue.

Biodegradation, Environmental↗