β-Glucan synthase induction in mushrooms grown on olive mill wastewaters

Beta-1-3-Glucan synthase activity and its induction by olive mill wastewaters (OMW) was studied in ten fungal strains (Auricularia auricula-judae, Lentinula edodes, Pleurotus eryngii, Stropharia aeruginosa, Agrocybe aegerita, P. pulmonarius, Armillaria mellea, P. ferulae, P. ostreatus, P. nebrodensis). A microtiter-based enzymatic assay on -1-3-glucan synthase activity was carried out on all mycelia growth both on the control medium and on OMW. Among the fungi assayed, L. edodes -1-3-glucan synthase was highly enhanced in OMW. The main components of OMW, i.e. phenols and lipids, were added separately to the control medium, to highlight the mechanism of L. edodes -1-3-glucan synthase induction. A Southern blot analysis and PCR with degenerated primers were carried out to detect the presence of fks1-like genes in these Basidiomycetes. The sequences obtained from the ten Basidiomycota were remarkably similar to fks1 from Filobasidiella neoformans. Spectrofluorimetric and RT-PCR analyses of -1-3-glucan synthase were performed on the mycelia of L. edodes. In this fungus, a strong stimulation of -1-3-glucan synthase mRNA and protein was recorded in the presence of OMW and phenol

Plant Growth-Promoting Microbes from Herbal Vermicompost

Overreliance on chemical pesticides and fertilizers has resulted in problems including safety risks, outbreaks of secondary pests normally held in check by natural enemies, insecticide resistance, environmental contamination, and decrease in biodiversity. The increasing costs and negative effects of pesticides and fertilizers necessitate the idea of biological options of crop protection and production. This includes the use of animal manure, crop residues, microbial inoculum, and composts. They provide natural nutrition, reduce the use of inorganic fertilizers, develop biodiversity, increase soil biological activity, maintain soil physical properties, and improve environmental health

Composting of wastes produced by low water consuming olive mill technology

Olive mill pomace (OMP) produced by low water consuming mill technologies (LWCT) were composted with chopped wheat straw in a forced aerated static pile. During the process temperature, oxygen consumption, moisture content, pH, electrical conductivity, total organic carbon, total extractable carbon, humic and fulvic acids, nitrogen, C/N, phenols, lipids and lignin were determined. Urease and casein-hydrolysing protease activities were also assayed. The humification was assayed following the degree of humification, the humification rate and the humification index which respectively reached the values of 0.12, 89% and 15% during the maturation phase. The analyses of final product revealed the presence of considerable amounts of mineral nutrients and stabilized organic matter and absence of harmful levels of heavy metals. The phytotoxicity disappeared at the end of the thermophilic phase.Peer Reviewe

Evolution of humic acid molecular weight as an index of compost stability

This paper proposes an index for the evaluation of compost maturity based on the evolution of molecular weights of humic acids (HA) during composting. The evolution of HA molecular weight was followed during the composting of both olive mill wastewater (OMW) and olive mill pomace (OMP). The wastes were composted in forced aeration static piles. Samples of the compost were collected at different times during composting. The elution profiles of HA obtained by gel filtration (Sephadex G-150) showed the disappearance of fractions with molecular weights ≤ 50 KDa and the contemporary increase of fraction with molecular weights ≥ 102 KDa. In this range, two fractions can be separated: the first one (A1) with molecular weights greater than 102 KDa and below 2 102 KDa, and the second one (A2) with molecular weight greater than 2 102 KDa. During composting, the ratio A2/A1 tends to reach a constant value which indicates the evolution toward the polymerization of HA. The ratio A2/A1 was named HAEI (Humic Acid Evolution Index). It varies with the material composted and the composting process and represents the maximum possible degree of HA polymerization, A comparison between HAEI and the usually used maturity indexes is also presented.Peer Reviewe