Endophytic microbes modulate plant responses to abiotic stresses: a review

Many groups of microorganisms have been studied for their benefits towards humankind due to their capacity to produce natural compounds that can be valorized in many economic sectors such as agriculture. Due to the extensive use of chemicals pesticides and fertilizers, current agriculture systems facing several major problems such as emergence of resistant in pathogens and pests, soil infertility and bioaccumulation of toxic residues in the environment and particularly in foods which negatively affects human health. The use of natural products harmless to plants, humans and biodegradable constitute a promising way to overcome these problems. Modern agriculture systems are moving toward the use of beneficial microorganisms isolated from the soil, plant surfaces and inside tissues for developing eco-friendly products such as biofertilizers and biopesticides. Recent literatures show that colonization of plants by endophytes is the rule in nature and endophyte-free plant is a rare exception. Endophytes are microbes living inside plant tissues and supporting them in growth and development, as well as stresses tolerance without causing any apparent disease symptom. Abiotic stresses have a great impact on growth, production and health of plants. Many literatures show the role of endophytes in abiotic stress tolerance as well as mechanisms involved to cope with these constraints via the induction of stress-related genes and molecules. This review provides a summary of literature on how endophytes modulate plant growth and responses to abiotic stresses which may help to better understand their role in plant adaptation to environmental constraints and valorize their use in agriculture

Prospecting bacterial volatile organic compounds antifungal activities against postharvest diseases

Chemical pesticides have a plenty of negative impacts on human health and on the environment. Thus, modern agriculture cropping systems are moving towards more eco-friendly alternatives. This study aims to investigate the bioprotective effect of three volatile organic compounds (VOCs: N-Ethylaniline, 2-Heptanone and 3-Methylbutan-1-ol) produced by endophytic bacteria against 21 phytopathogenic fungal strains and their bioprotective effect on horticulture products i.e. tomato and lemon fruits and Potato tubers. The results showed that N-Ethylaniline and 3-methylbutan-1-ol had better antagonistic activity against the fungal strains by inhibiting the mycelia growth of the studied fungal strains at different concentrations. The N-Ethylaniline showed the lowest effective concentration (EC50) against B. cinerea strain S5 (0,258 mL/L headspace), Fusarium solani strain SB4.15.1 (0,496 mL/L headspace) and Colletotrichum gloeosporioides strain ManS3Fr02 (0,206 mL/L headspace). At EC50 this compound significantly reduced B. cinerea and C. gloeosporioides infections on tomato and lemon fruits, respectively. However, N-Ethylaniline didn’t showed significant effect on F. solani infection on Potato tubers. This study showed the broad spectrum of in vitro antifungal activity of N-Ethylaniline and its effect to reduce postharvest infections of some fungal diseases suggesting its potential use as a biofumigant

Biochemical Characterization of Coriander Cakes Obtained by Extrusion

This study was designed to examine the effect of operating conditions such as nozzle diameter on fatty acid, sterol, and tocol composition of coriander cakes. Eight fatty acids were identified, with petroselinic acid accounting for 75-77% of the total fatty acids, followed by linoleic, oleic, and palmitic acids, accounting for 12-13%, 5% and 3%, respectively, of the total fatty acids. beta-Sitosterol was the major sterol in all oils with 33-35% of total sterols. The next major sterols in all oils were stigmasterol (24% of total sterols) and Delta(7)-stigmasterol (15% of total sterols). Coriander cake contained higher amounts of total tocotrienol where gamma-tocotrienol was the main compund

Endophytic microbes modulate plant responses to abiotic stresses: a review

Many groups of microorganisms have been studied for their benefits towards humankind due to their capacity to produce natural compounds that can be valorized in many economic sectors such as agriculture. Due to the extensive use of chemicals pesticides and fertilizers, current agriculture systems facing several major problems such as emergence of resistant in pathogens and pests, soil infertility and bioaccumulation of toxic residues in the environment and particularly in foods which negatively affects human health. The use of natural products harmless to plants, humans and biodegradable constitute a promising way to overcome these problems. Modern agriculture systems are moving toward the use of beneficial microorganisms isolated from the soil, plant surfaces and inside tissues for developing eco-friendly products such as biofertilizers and biopesticides. Recent literatures show that colonization of plants by endophytes is the rule in nature and endophyte-free plant is a rare exception. Endophytes are microbes living inside plant tissues and supporting them in growth and development, as well as stresses tolerance without causing any apparent disease symptom. Abiotic stresses have a great impact on growth, production and health of plants. Many literatures show the role of endophytes in abiotic stress tolerance as well as mechanisms involved to cope with these constraints via the induction of stress-related genes and molecules. This review provides a summary of literature on how endophytes modulate plant growth and responses to abiotic stresses which may help to better understand their role in plant adaptation to environmental constraints and valorize their use in agriculture

Glutaraldehyde test for the rapid diagnosis of pulmonary and extra-pulmonary tuberculosis in an area with high tuberculosis incidence

BACKGROUND Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide. The primary method for controlling TB is the rapid and accurate identification of infected individuals. Immune response exploitation represents one of the main methods used for early TB diagnosis; however, few studies have reported that whole blood originating from TB-infected patients gels faster in the presence of aldehyde than blood originating from healthy subjects, which is the focus of the current study. OBJECTIVES The study objectives are to determine the diagnostic value of a glutaraldehyde test (GT) in pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (EPTB) and to assess its performance compared with light-emitting diode fluorescence microscopy (LED-FM). MATERIALS AND METHODS This study included 272 specimens (176 suspected PTB specimens and 96 suspected EPTB specimens). Of the 272 patients, 98 patients had TB infection confirmed by culture (64 PTB cases and 34 EPTB cases), and 174 patients had no TB infection. The gold standard technique (culture) was used as reference to verify the GT's performance. RESULTS The GT showed a high sensitivity (96.9%) and specificity (82.1%) for PTB with a good positive predictive value (PPV = 75.6%) and negative predictive value (NPV = 97.9%). For EPTB, the GT showed a sensitivity of 91.2% and a specificity of 77.4%, with PPV = 68.9% and NPV = 94.1%. LED-FM had lower sensitivities for PTB (65.6%) and EPTB (42.1%) and an excellent specificity of 100%, with PPV = 100% and NPV = 100%. CONCLUSION We concluded that GT is rapid, easy, simple and cost-effective and does not require qualified personnel with a specific background or sophisticated equipment like molecular biology or mycobacterium-specific genotyping techniques. These qualities make the GT attractive for use in low- and high-income countries in addition to other conventional methods, particularly culture, which continues to be the gold standard

Prospecting bacterial volatile organic compounds antifungal activities against postharvest diseases

Chemical pesticides have a plenty of negative impacts on human health and on the environment. Thus, modern agriculture cropping systems are moving towards more eco-friendly alternatives. This study aims to investigate the bioprotective effect of three volatile organic compounds (VOCs: N-Ethylaniline, 2-Heptanone and 3-Methylbutan-1-ol) produced by endophytic bacteria against 21 phytopathogenic fungal strains and their bioprotective effect on horticulture products i.e. tomato and lemon fruits and Potato tubers. The results showed that N-Ethylaniline and 3-methylbutan-1-ol had better antagonistic activity against the fungal strains by inhibiting the mycelia growth of the studied fungal strains at different concentrations. The N-Ethylaniline showed the lowest effective concentration (EC50) against B. cinerea strain S5 (0,258 mL/L headspace), Fusarium solani strain SB4.15.1 (0,496 mL/L headspace) and Colletotrichum gloeosporioides strain ManS3Fr02 (0,206 mL/L headspace). At EC50 this compound significantly reduced B. cinerea and C. gloeosporioides infections on tomato and lemon fruits, respectively. However, N-Ethylaniline didn’t showed significant effect on F. solani infection on Potato tubers. This study showed the broad spectrum of in vitro antifungal activity of N-Ethylaniline and its effect to reduce postharvest infections of some fungal diseases suggesting its potential use as a biofumigant

Glutaraldehyde test for the rapid diagnosis of pulmonary and extra-pulmonary tuberculosis in an area with high tuberculosis incidence

BACKGROUND Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide. The primary method for controlling TB is the rapid and accurate identification of infected individuals. Immune response exploitation represents one of the main methods used for early TB diagnosis; however, few studies have reported that whole blood originating from TB-infected patients gels faster in the presence of aldehyde than blood originating from healthy subjects, which is the focus of the current study. OBJECTIVES The study objectives are to determine the diagnostic value of a glutaraldehyde test (GT) in pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (EPTB) and to assess its performance compared with light-emitting diode fluorescence microscopy (LED-FM). MATERIALS AND METHODS This study included 272 specimens (176 suspected PTB specimens and 96 suspected EPTB specimens). Of the 272 patients, 98 patients had TB infection confirmed by culture (64 PTB cases and 34 EPTB cases), and 174 patients had no TB infection. The gold standard technique (culture) was used as reference to verify the GT's performance. RESULTS The GT showed a high sensitivity (96.9%) and specificity (82.1%) for PTB with a good positive predictive value (PPV = 75.6%) and negative predictive value (NPV = 97.9%). For EPTB, the GT showed a sensitivity of 91.2% and a specificity of 77.4%, with PPV = 68.9% and NPV = 94.1%. LED-FM had lower sensitivities for PTB (65.6%) and EPTB (42.1%) and an excellent specificity of 100%, with PPV = 100% and NPV = 100%. CONCLUSION We concluded that GT is rapid, easy, simple and cost-effective and does not require qualified personnel with a specific background or sophisticated equipment like molecular biology or mycobacterium-specific genotyping techniques. These qualities make the GT attractive for use in low- and high-income countries in addition to other conventional methods, particularly culture, which continues to be the gold standard.</div