Estimating the Prevalence of Foodborne Pathogen Campylobacter jejuni in Chicken and Its Control via Sorghum Extracts

Campylobacter jejuni is a Gram-negative bacterium which is considered as the most reported cause of foodborne infection, especially for poultry species. The object of this work is to evaluate the occurrence of C. jejuni in chicken meat as well its control via three types of sorghum extracts (white sorghum (WS), yellow sorghum (YS), and red sorghum (RS)); antibacterial activity, antioxidant power, and cytotoxicity of sorghum extracts were also assessed. It was found that C. jejuni is very abundant in chicken meat, especially breast and thigh. WS extract showed more effectiveness than both yellow and red ones. Lyophilized WS extract offered high total phenolic compounds (TPCs) and total flavonoid compounds (TFCs) of 64.2 ± 0.8 mg gallic acid equivalent (GAE/g) and 33.9 ± 0.4 mg catechol equivalent (CE)/g, respectively. Concerning the antibacterial and antioxidant activities, WS showed high and significant antibacterial activity (p < 0.001); hence, WS displayed a minimum inhibitory concentration (MIC) of 6.25%, and revealed an inhibition zone of 7.8 ± 0.3 mm; it also showed an IC50 at a concentration of 34.6 μg/mL. In our study, different samples of chicken fillet were collected and inoculated with pathogenic C. jejuni and stored at 4 °C. Inoculated samples were treated with lyophilized WS extract at (2%, 4%, and 6%), the 2% treatment showed a full reduction in C. jejuni on the 10th day, the 4% treatment showed a full reduction in C. jejuni on the 8th day, while the 6% treatment showed a full reduction in C. jejuni on the 6th day. Additionally, 2%, 4%, and 6% WS extracts were applied on un-inoculated grilled chicken fillet, which enhanced its sensory attributes. In sum, WS extract is a promising natural preservative for chicken meat with accepted sensory evaluation results thanks to its high antibacterial and antioxidant potentials

Recherche de mécanismes de résistance à l'Orobanche chez des génotypes de tomate (aspects histologiques, physiologiques, moléculaires et génétiques)

La tomate est l'une des cultures les plus menacées par une plante parasite, l'Orobanche. Nous avons recherché des sources de résistance à deux espèces O. aegyptiaca et O. ramosa. Certaines espèces sauvages de tomate, sont apparues intéressantes, notamment L. pennellii. Elle à fait l'objet d'études plus approfondies grâce à un système de co-culture hydroponique du pathosystème. L. pennellii produit des exsudats racinaires inhibant la germination des graines d'Orobanche et induit des nécroses des tubercules fixés sur ses racines. Des lignifications des racines infestées et l'expression de gènes de la voie de biosynthèse de la lignine ont été suivies. Par ailleurs 50 lignées d'introgression de L. pennellii dans un génotype cultivé et sensible ont été confrontées au parasite pour préciser la localisation génétique de ces gènes de résistance.In the Mediterranean area and the Nile Valley broomrape, a parasitic plant, causes severe yield losses in tomato fields. In order to find broomrape resistant tomato genotypes a screening of numerous wild, varieties and introgression lines was carried out, first under greenhouse conditions, then in an in vitro co-culture. One of the most interesting genotype, Lycopersicon pennellii, produces root exudates which inhibit broomrape germination and induce necrosis of the parasitic tubercles. Host responses involved cell wall thickening lignin deposition and xylem vessel occlusion. The expression of some genes from the lignin biosynthesis pathway was shown to be rapidly induced in L. pennellii infested by broomrape.NANTES-BU Sciences (441092104) / SudocSudocFranceF

Preparation of a Pectinase-Enriched Multienzyme under Solid State Fermentation of Sugarcane Bagasse

Enzyme mediated degradation of lignocellulosic biomass is an important step in waste-biorefineries. Multienzyme preparations can effectively degrade complex materials and, hence, can be applied in biorefineries. Here, an agro-industrial waste, sugarcane bagasse, was used to produce a bacterial multienzyme. The bacterial strains including B. thuringiensis B45, B. velezensis BF3 and B. amyloliquefaciens B987 exhibited their growth at temperatures from 30&ndash;50 &deg;C in the presence of 2% salt. The isolates B45, BF3 and B987 were able to produce endoglucanase, xylanase and pectinase, respectively. Therefore, it was aimed to obtain a multienzyme preparation by cultivating the bacterial consortium under a solid-state fermentation of untreated and chemically treated sugarcane bagasse. The results showed that the titres of cellulase and xylanase were generally higher when the strain B45 cultivated at the start of the fermentation. Interestingly, the degradation of cellulose and hemicellulose present in sugarcane bagasse by the strains B45 and BF3 rendered the mere pectin component available to the pectinolytic strain B987. The degradation of SB by the consortium was confirmed by gravimetric analysis and scanning electron microscopy. The study showed that the bacterial strains can be cultivated under solid-state fermentation to obtain industrially important enzymes

Preparation of a Pectinase-Enriched Multienzyme under Solid State Fermentation of Sugarcane Bagasse

Enzyme mediated degradation of lignocellulosic biomass is an important step in waste-biorefineries. Multienzyme preparations can effectively degrade complex materials and, hence, can be applied in biorefineries. Here, an agro-industrial waste, sugarcane bagasse, was used to produce a bacterial multienzyme. The bacterial strains including B. thuringiensis B45, B. velezensis BF3 and B. amyloliquefaciens B987 exhibited their growth at temperatures from 30–50 °C in the presence of 2% salt. The isolates B45, BF3 and B987 were able to produce endoglucanase, xylanase and pectinase, respectively. Therefore, it was aimed to obtain a multienzyme preparation by cultivating the bacterial consortium under a solid-state fermentation of untreated and chemically treated sugarcane bagasse. The results showed that the titres of cellulase and xylanase were generally higher when the strain B45 cultivated at the start of the fermentation. Interestingly, the degradation of cellulose and hemicellulose present in sugarcane bagasse by the strains B45 and BF3 rendered the mere pectin component available to the pectinolytic strain B987. The degradation of SB by the consortium was confirmed by gravimetric analysis and scanning electron microscopy. The study showed that the bacterial strains can be cultivated under solid-state fermentation to obtain industrially important enzymes

Evaluation of the Adsorption Efficacy of Bentonite on Aflatoxin M1 Levels in Contaminated Milk

The existence of aflatoxin M1 (AFM1) in raw milk results in economic losses and public health risks. This research aims to examine the capability of bentonite to adsorb and/or eliminate AFM1 from various raw milk types. In addition, the effects of numerous bentonites (HAFR 1, 2, 3 and 4) on the nutritional characteristics of the milk were studied. Our findings revealed that goat milk had the highest value of AFM1 (490.30 ng/L) in comparison to other milks. AFM1 adsorption was influenced by applying bentonite (0.5 and 1 g) in a concentration-dependent manner for different time intervals (from 0 to 12 h). The percentage of AFM1 reached the maximum adsorption level after 12 h to 100, 98.5 and 98% for bentonites HAFR 3, 1 and 2, respectively. HAFR 3 (1 g bentonite) presented higher adsorption efficiency than other bentonites used in the phosphate buffer saline (PBS) and milk. Residual levels of AFM1 reached their lowest values of 0 and 1.5 ng/L while using HAFR 3 in PBS and milk, respectively. With regard to the influence of bentonite on the nutritional characteristics of milk, there was an increase in fat, protein and solid non-fat ratio while using HAFR 3 and 4, yet decreased lactose in comparison with the control. Scanning Electron Microscopy and Fourier Transform-Infrared Spectroscopy both identified bentonites as superior AFM1 binders. The results demonstrated that bentonite, particularly HAFR 3, was the most effective adsorbent and could thus be a promising candidate for the decontamination of AFM1 in milk