CHEMICAL COMPOSITION OF ESSENTIAL OILS OF EUGENIA CARYOPHYLLA AND MENTHA SP CF PIPERITA AND THEIR IN VITRO ANTIFUNGAL ACTIVITIES ON SIX HUMAN PATHOGENIC FUNGI

Background: Many fungal infections are responsible for human skin damages, to control their negative action, some aromatic and medicinal plants are traditionally used by local population in Cameroon. The present study was carried out to determine the chemical composition of essential oils of Eugenia caryophylla and Mentha sp cf piperita and their antifungal activity on some human pathogenic fungi. Materials and methods: Essential oils from Eugenia caryophylla and Mentha sp cf piperita were extracted by steam distillation using Clevenger apparatus and the antifungal activity was evaluated on six human pathogenic fungal strains; two yeasts (Candida albicans 1 and Candida albicans 2) and four dermatophytes (Tricophyton rubrum 1, T. rubrum 2, T. violaceum, and T. soudanensis) using modified broth microdilution method M27-A3 and M38-A respectively. Results: The essential oils obtained yielded of 5.9 for Eugenia caryophylla and 0.2% Mentha sp cf piperita respectively. The chemical composition was assigned by GC and GC/SM and showed that E. caryophylla was mainly composed of eugenol (80.0 %), -caryophyllene (8.3%), and eugenol acetate (6.7%) while Mentha sp cf piperita was characterized by piperitone (67.5 %), menthol (10.0 %) and ß-phellandrene (5.8%). The result showed that essential oil of E. caryophylla exhibit the highest antifungal activity with MICs and MFC of 0.25µL/mL and 0.125µL/mL for filamentous fungi and MIC of 0.5 µL/mL for both yeast strains while MFC value was 1 µL/mL for one yeast strain and not determined for the second. MFCs Mentha sp cf piperita essential oil showed a weak activity with a MIC of 2.5 µL/mL on Tricophyton strains while no activity was exhibited on Candida albicans strains. Conclusion: The results of this work can be used to confirm their traditional uses and can also be proposed as natural ingredients to some industries to treat superficial infections

Variation de la thermoresistance de la spore bacterienne (Bacillus stearothermophilus) en cours de germination

SIGLECNRS T 56987 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Growth and α-amylase production by strains of Lactobacillus plantarum and Rhizopus oryzae cultures in cassava starch medium

A cassava starch medium was used to analyse the dynamics of batch growth and α-amylase production of strains of Lactobacillus plantarum and Rhizopus oryzae isolated from cassava dried chips. The strains displayed a growth of 0.5h-1 and 0.55 h-1, a biomass yield on cassava starch of 0.49g/g and 0.5g/g, a maximum specific cassava starch uptake rate (μm/Yx/s) of 2.98 mmol g-1 h-1 and 3.21 mmol g-1 h-1, a maximum oxygen uptake rate of 14.7 mmol g,sup>-1h-1 and 12.94 mmol g-1h-1, an oxygen efficiency of growth of 0.565 and 0.58, a carbon recovery of 1.035 and 0.97, and an energy recovery of 1.0 and 0.95 respectively. Enough α-amylase enzymes were synthesized, and cassava starch hydrolysis was not a limiting factor for growth of both strains. Theses results suggest the possibility to use these strains for developing a dual starter culture for cassava fermentation, and α-amylase production from cassava starch medium. Keywords: cassava, α-amylase, Lactobacillus plantarum, Rhizopus oryzae, starter culture Cameroon Journal of Experimental Biology Vol. 1(2) 2005: 107-11

Traditional Processing, Physicochemical Property, Phytochemical Content, and Microbiological and Sensory Quality of the Yellow “Téa Lémi” Wine Made in the Far-North of Cameroon

“Téa Lémi” is a traditional wine made from pummelos by the Kapsiki in the Far-North of Cameroon. Despite its importance as a source of income for the country people, the know-how supporting production of this beverage and its quality attributes still remain unknown. Hence, this study was aimed at describing the processing and quality of “Téa Lémi” produced and marketed in northern Cameroon. The field investigation and the ethnographical technique were used to describe the production process. Physicochemical, phytochemical, and microbiological properties of the beverage were examined using referenced techniques. Quantitative descriptive analysis was used for describing the sensory profile of the wine. Surveys showed that processing of the grapefruit wine is typically artisanal. This can be seen by the uncontrolled addition of some ingredients such as sugar, extract of banana, and honey and a significant fermentation step started by wild, unselected yeasts. The physicochemical analyses revealed that the wine had an acid pH of around 3.84, with a total acidity between 7.72 g/L and 8.79 g/L. The alcohol and soluble solids contents were 14% (v/v) and 12 °Brix, respectively. Total sugar and conductivity values ranged from 57.8 to 96.8 g/L and 573 to 686 μS/cm. Mean contents of polyphenols and flavonoids of 616.4 mg PE/L and 322.5 mg QE/L and an antioxidant capacity of 261.03 mg TE/L have been revealed in the indigenous wine, respectively. The assessment of hygienic quality showed alarming sign of microbiological contamination revealed by total aerobic bacteria and spore-forming bacteria counts beyond the critical level. The good sensory quality (13 out of 20) of the grapefruit wine seemed to be linked to the sweetness (r = 0.999; p<0.001) and odor/flavor (r = 0.997; p<0.001). The beverage has been described by the panel as pale yellow colored, slightly tart, and bitter accompanied by some fruity esters and sweet notes of citrus and caramelized sugar

Effects of Cattle Manure Wood-Ash Compost on Some Chemical, Physical and Microbial Properties of Two Acid Tropical Soils

A field study was conducted to assess the potential of cattle manure wood-ash compost in order to improve soil fertility and productivity in two areas in the centre region of Cameroon distant of 200 km. The farms were amended with four types of compost, C1 (100% cattle manure compost), C2 (95% cattle manure with 10% wood ash admixture), C3 (90% cattle manure compost and 10% wood ash admixture), and C4 (85% cattle manure compost and 15% wood ash admixture). &nbsp;Soybean was the growing plant during the experiment which lasted three months. After the harvesting, physical, chemical, biological and plant parameters were evaluated. The compost significantly increased soil pH, Electrical conductivity, total organic carbon, total nitrogen, concentrations of Ca2+, Mg2+, K+, Na+, and total phosphorus. The composts also had a stimulatory effect on the total soil bacteria and fungi, cellulase and protease activities. Improvement soil physical, chemical and microbial parameters enhanced biomass production and yield. In summary, cattle manure wood-ash composts could be used for alleviating soil acidity and improve soil fertility of tropical acid soils. Future research is needed to address its sustainability in a long-term study

Antagonism of Trichoderma asperellum against Phytophthora megakarya and its potential to promote cacao growth and induce biochemical defence

This work aimed to assess the antagonism effects of four different Trichoderma asperellum isolates against Phytophthora megakarya and their ability to enhance cacao growth and biochemical defence. Results showed that In paired culture, all the isolates of T. asperellum used were antagonistic to P. megakarya by means of mycoparasitism. In pot experiments, leaf number, plant height, shoots and root dry matter were significantly increased by T. asperellum. Similarly, chlorophyll rate, P uptake and acid phosphatase activities were also increased. These antagonists reduced significantly the effects of P. megakarya in the leaves of cacao plants. Amino acid and phenolic components content increased in either healthy or infected leaves from cacao plants inoculated with T. asperellum. There was negative correlation between both phenolic compounds and disease severity and amino acids and disease severity. This suggests that these compounds are involved in disease resistance. In fact, the induction of specific amino acids such as alanine, glutamic acid and methionine may play an important role in the adaptation of cacao plant to P. megakarya infection. These findings demonstrated that Trichoderma asperellum (PR10, PR11, PR12 and PR659-7) could be used to improve the development of cacao plants and protect the plant against Phytophthora megakarya