Valorisation of essential oil of Eucalyptus populifolia Desf, Eucalyptus woollsiana and Eucalyptus exserta for agro-industrial purposes.

Forest species are characterized by their wealth of essential oils (EOs), which play key requested for alternative control methods against weeds, fungi and pests. This study reports the chemical composition and highlight the antioxidant, antifungal and phytotoxic properties of the EOs obtained from Eucalyptus populifolia Desf, Eucalyptus woollsiana and Eucalyptus exserta. The EOs were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Their antioxidant, antifungal and phytotoxic properties were investigated. All EOs displayed a specific richness in eucalyptol (75.94-7.01%), camphene (6.97-0.4%) globulol (5.20-5.83%) and α-pinene (0.71-12.82 %). EOs isolated from E. populifolia exhibited significant antioxidant activity. Furthermore, all investigated EOs displayed significant antifungal properties against four phytopathogenic fungi belonging to Fusarium genus. The phytotoxic activity against five weeds showed varying effectiveness on seed germination and seedling growth, which exhibited greater effectiveness compared to glyphosate. Eucalyptus EOs have the potential to be used in the formulation of biopesticides.

[Evaluation of depression in elderly people living in nursing homes: a study involving 35 people]. / De la dépression chez la personne âgée en maison de retraite: Etude auprès de 35 résidents.

BACKGROUND: Depression in the elderly is often inadequately diagnosed and insufficiently treated. Regardless of the nature of the depression, the influence and the impact of the biological, situational, social and psychological factors would be more important in old subjects than in young ones when the disorder occurs. The nursing home, as an institution, is another factor facilitating the appearance of depression. AIM: The aim of our survey is to determine the prevalence of depression in old people living in a nursing home and to evaluate the degree of their autonomy. METHODS: Our study is a transverse, descriptive and analytical survey carried out on 35 old people at a nursing home in Sfax. Forty residents were excluded from this survey for reasons of dementia (25 cases), debility (5 cases), disabling psychiatric pathologies (4 cases), deafness (5 cases) and one resident who refused the interview. The evaluation has been achieved using two scales specific to the geriatric practice: • The scale of depression: GDS (geriatric depression Scale) applied to 30 items. • The scale of autonomy: IADL (Instrumental Activities of Daily Living) applied to 6 items. RESULTS: • The examined population was composed of 35 people aged from 65 to 93 with a sex ratio of 1.05. • 51.4% of the residents were in a state of depression. • Depression was more frequent in: • Female subjects (58.8% of women compared to 44.4% of men) • Subjects aged less than 70 (66% of subjects aged less than 70 versus 40% of older subjects) • 17.1% of the residents were independent, 42.9% were dependent and 40% were heavily dependent. CONCLUSION: Depression in the elderly is related to several depressice factors particularly for patients living in institution. This situation needs very important adaptive capacities.

Highly thermostable xylanase of the thermophilic fungus Talaromyces thermophilus: purification and characterization.

A thermostable xylanase from a newly isolated thermophilic fungus Talaromyces thermophilus was purified and characterized. The enzyme was purified to homogeneity by ammonium sulfate precipitation, diethylaminoethyl cellulose anion exchange chromatography, P-100 gel filtration, and Mono Q chromatography with a 23-fold increase in specific activity and 17.5% recovery. The molecular weight of the xylanase was estimated to be 25 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration. The enzyme was highly active over a wide range of pH from 4.0 to 10.0. The relative activities at pH5.0, 9.0, and 10.0 were about 80%, 85.0%, and 60% of that at pH7.5, respectively. The optimum temperature of the purified enzyme was 75 degrees C. The enzyme showed high thermal stability at 50 degrees C (7 days) and the half-life of the xylanase at 100 degrees C was 60 min. The enzyme was free from cellulase activity. K (m) and V (max) values at 50 degrees C of the purified enzyme for birchwood xylan were 22.51 mg/ml and 1.235 micromol min(-1) mg(-1), respectively. The enzyme was activated by Ag(+), Co(2+), and Cu(2+); on the other hand, Hg(2+), Ba(2+), and Mn(2+) inhibited the enzyme. The present study is among the first works to examine and describe a secreted, cellulase-free, and highly thermostable xylanase from the T. thermophilus fungus whose application as a pre-bleaching aid is of apparent importance for pulp and paper industries.