Sugar beet leaves as source of lyase in bioprocess producing green note aldehydes

Poster (2007)

Sugar beet leaves were used as source of lyase in a biocatalytic process for the production of C6-aldehydes. Their hydroperoxide lyase activity was revealed important. The optimum values of pH and ... [more ▼]

Sugar beet leaves were used as source of lyase in a biocatalytic process for the production of C6-aldehydes. Their hydroperoxide lyase activity was revealed important. The optimum values of pH and temperature for reactions were respectively 6.7 and 22 °C. A simple and fast process providing high molar conversion of hydroperoxides to aldehydes is proposed. The yield of the main product cis-3-hexenal reached 80% after only 2 min and was stabilised by acidifying the reaction medium to pH 2. [less ▲]

Bacteriocin producers from traditional food products

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2007), 11(4), 275-281

A total of 220 strains of LAB isolated from 32 samples of traditional fermented food from Senegal were screened for bacteriocin production. Two bacteriocin producers, Lactococcus lactis subsp. lactis and ... [more ▼]

A total of 220 strains of LAB isolated from 32 samples of traditional fermented food from Senegal were screened for bacteriocin production. Two bacteriocin producers, Lactococcus lactis subsp. lactis and Enterococcus faecium, were identifi ed from 12 bacteriocin-producing isolates on the basis of phenotypic analyses and 16S rDNA sequence. Both bacteriocins produced by new isolates show antimicrobial activity against Listeria monocytogenes and Bacillus coagulans whereas only that produced by Lactococcus lactis has an activity against Bacillus cereus. Bacteriocin-producing Lactococcus lactis strains were found in a variety of traditional foods indicating a high potential of growth of this strain in variable ecological complex environment. Partial 16S rDNA of the two bacteriocin producers obtained in this study has been registered to Genbank databases under the accession number AY971748 for Lactococcus lactis subsp. lactis (named CWBI-B1410) and AY971749 for Enterococcus faecium (named CWBI-B1411). The new bacteriocin-producing Lactococcus lactis subsp. lactis strain has been selected for identification and application of the bacteriocin to food preservation. [less ▲]

Storage Of Yarrowia Lipolytica Lipase After Spray-Drying In The Presence Of Additives

in Process Biochemistry (2007), 42(9),

Lipase from Yarrowia lipolytica is an enzyme that presents numerous potentialities for biotechnological applications. This work describes the development of powders obtained by atomization of supernatants ... [more ▼]

Lipase from Yarrowia lipolytica is an enzyme that presents numerous potentialities for biotechnological applications. This work describes the development of powders obtained by atomization of supernatants lipase from Y. lipolytica LGx6481. Two formulations were studied: one formulation with skim milk powder and gum arabic, and the other with maltodextrin, calcium chloride and gum arabic. After drying, powders were stored at 4 and 20 8C in aluminium hermetic bags to evaluate their stability over a period of one year. The influence of water activity and glass transition temperature (Tg) on the powder’s storage were also studied. [less ▲]

Xylanase production by Penicillium canescens in solid-state fermentation.

Poster (2006, October)

Selection of bacteriocin-producing lactic acid bacteria from Senegal traditional fermented food

Poster (2006, September)

Valorisation des feuilles de betteraves à travers la production de molécules à notes vertes.

Report (2006)

Toward a stochastic formulation of microbial growth in relation to bioreactor performances : case study of an E. coli fed-batch process

in Biotechnology Progress (2006), 22

Production and down-stream processing of an extracellular lipase from the yeast Yarrowia lipolytica

in Enzyme & Microbial Technology (2006), 38(6), 756-759

Lipase constitutes an interesting class of enzyme with many biotechnological applications. However, the development of a fruitful process must be set up to obtained a product compatible with the ... [more ▼]

Lipase constitutes an interesting class of enzyme with many biotechnological applications. However, the development of a fruitful process must be set up to obtained a product compatible with the industrial and commercial needs. Here, we report the development of such a process for the extracellular lipase secreted by the yeast Yarrowia lipolytica. The enzyme production, carried out in a 2000 L bioreactor, led to a lipase activity of approximately 1100 U mL(-1) after 53 h of fermentation. The post-culture treatment, consisting of a centrifugation, a filtration and an ultra-filtration steps, led to 15-fold volume reduction and a 8-fold increased of the lipase activity. Finally, addition of 12% of milk powder and 3% of gum arabic before spray-drying dehydration led to a stable powder with a lipolytic activity of 37,500 U g D.W.(-1). (c) 2005 Elsevier Inc. All rights reserved. [less ▲]

Assessment Off The Physiological And Biochemical Characterization Off A Lactic Acid Bacterium Isolated From Chicken Faeces In Sahelian Region

in African Journal of Biotechnology (2006), 5(8),

Involvement of fengycin-type lipopeptides in the multifaceted biocontrol potential of Bacillus subtilis

in Applied Microbiology & Biotechnology (2005), 69(1), 29-38

In this work, the potential of Bacillus subtilis strain M4 at protecting plants against fungal diseases was demonstrated in different pathosystems. We provide evidence for the role of secreted ... [more ▼]

In this work, the potential of Bacillus subtilis strain M4 at protecting plants against fungal diseases was demonstrated in different pathosystems. We provide evidence for the role of secreted lipopeptides, and more particularly of fengycins, in the protective effect afforded by the strain against damping-off of bean seedlings caused by Pythium ultimum and against gray mold of apple in post-harvest disease. This role was demonstrated by the strong biocontrol activity of lipopeptide-enriched extracts and through the detection of inhibitory quantities of fengycins in infected tissues. Beside such a direct antagonism of the pathogen, we show that root pre-inoculation with M4 enabled the host plant to react more efficiently to subsequent pathogen infection on leaves. Fengycins could also be involved in this systemic resistance-eliciting effect of strain M4, as these molecules may induce the synthesis of plant phenolics involved in or derived from the defense-related phenylpropanoid metabolism. Much remains to be discovered about the mechanisms by which Bacillus spp suppress disease. Through this study on strain M4, we reinforce the interest in B. subtilis as a pathogen antagonist and plant defense-inducing agent. The secretion of cyclic fengycin-type lipopeptides may be tightly related to the expression of these two biocontrol traits. [less ▲]