Metagenomic analysis of the bacterial microbiota linked to the traditional Algerian date product "Btana"

In this study, using high throughput pyrosequencing, we highlighted the bacterial diversity of the traditional Algerian date product "Btana" that is produced in southern Algeria using both direct (DBM) and indirect (UBM) methods. Metagenomic analysis yielded a total of 103,379 reads, with a 606 total operational taxonomic units (OTUs) detected. Firmicutes represented 84.79 % of the total pyrosequencing reads. Phylogenetic analysis revealed that the Bacillales represented 90.20 % ± 15.12 % of the total reads. Among the phylotypes detected, Bacillus was the dominant genus (39.53 %). While Bacillus megaterium was shared among all of the samples, its distribution varied widely. Non-metric multidimensional scaling (nMDS) analysis showed that UBM samples clustered together, and three main OTUs were found in these UBM samples: Paenibacillus polymyxa, Paenibacillus xylanexedens, and Planomicrobium JN082684. Correlation analysis showed no association between parametersof the samples (age, pH, water activity) and the specific microbiota

Bioethanol production from date palm fruit waste fermentation using solar energy

Every year, more than 236,807 tons, equivalent to 30% of date-palm fruits produced in Algeria, is lost during picking, storage, and commercialization processes. Gasification of this huge biomass can generate biogas such as bioethanol, biodiesel, gasoline and other useful substances. Bioethanol is becoming the main biofuel produced by chemical synthesis or anaerobic fermentation from biomass and is significant for industrial development, investment, and use. It is eco-friendly, moderately costly and cleaner than other gasses. Actually, due to modern biotechnologies, it is possible to valorise the common date-palm waste (CDPW) by bioconversion and to commercialize them in local and international markets in the form of new products with an acceptable added value such as bioethanol. CDPW is a renewable and sustainable resource of energy that is not greatly used in industries. The date is rich in biodegradable sugars, providing bioethanol after fermentation during 72 h at 30°C in the presence of Saccharomyces cerevisiae yeast and the distillation of date’s juice obtained. In the first experience, a solar batch fermenter (SBF) of 50L capacity, and a butane gas distiller using a cocotte (cooker) of 30L capacity was designed and constructed. The bioconversion systems led to the production of 250 mL/kg of ethanol at 90° after distillation of the CDPW juice at 78°. This is in comparison to the theoretical ethanol directly produced from sugar by chemical synthesis process. The 33% efficiency that was obtained appeared satisfactory and it encouraged the great scaling development of bioethanol based on CDPW biomass and other raw materials abundant in Algeria Sahara.Keywords: Algerian Sahara, bioethanol, dates-palms waste valorization, distillation, fermentation, solar energy, Saccharomyces cerevisia

Generation of bioethanol from common date byproducts, “Teggaza and Lebghel” in Southern Algeria

Date by-products constitute the principal food for the oasis populations in Middle East and North Africa. Dates contents consist of 70 to 80% of reducing sugars, and do not require an intensive energy and labour for thermophysical pre-treatment. They can serve as a good feedstock for bioethanol generation through fermentation and distillation. Algeria is among the top sixth producers of dates in the world with more than 250,000 tons/year; from these, more than 30% can be lost for different reasons and may be of low quality. In the laboratory, after an alcoholic fermentation of the substrate of the date varieties, Teggaza and Lebghel (T & L) using bakery yeast at 30°C for 72 h, the distilled and rectified date juice generated the highest ethanol ( 88° and 90°) with acceptable productions of 2.5 and 2.78 mL/kg/h, and assessed scale efficiencies of 23.57 and 26.2%. This is unlike the one (ethanol; 50%) directly generated by chemical reaction using the same quantity of sugar. The efficiencies that were obtained seem satisfactory and encourage the great scaling development of bioethanol generation using date waste biomass abundant in Algerian Sahara.Key words: Algerian Sahara, alcoholic fermentation, bioethanol, bakery yeast, dates by-product, distillation

Characterization of New Small-Spored <i>Alternaria</i> Species Isolated from <i>Solanaceae</i> in Algeria

Although large-spored Alternaria species of the section Porri are considered to be the major agents responsible for leaf spot and blight of Solanaceae, small-spored Alternaria species are also frequently isolated from symptomatic tissues. A survey of the north-western regions of Algeria during the 2017–2018 growing seasons revealed that amongst the 623 Alternaria isolates from tomato, potato, pepper, eggplant and black nightshade, 8% could not be morphologically assigned to either section Porri or section Alternaria. In order to more precisely determine the taxonomic position of these isolates, detailed morphological characterizations and multi-locus phylogenetic analyses were performed. Based on these analyses, the isolates were grouped into four main clades: section Ulocladioides, section Infectoriae, including two new species, section Embellisioides, and section Eureka, including one new species. These isolates were also characterized for their virulence under green-house conditions. They were able to produce leaf spot symptoms on tomato plants but with variable levels

Metabarcoding analysis and fermentation performance of the dominant fungal microbiota associated with the Algerian traditional date product “Btana”

The study highlights the fungal diversity of the traditional Algerian date’s product “Btana” prepared with direct Btana method (DBM) and undirect Btana method (UBM). Btana fungal populations were analyzed through 28S metabarcoding. Data treatment resulted in 122,997 reads representing three Phyla in which 76% reads (46 OTUs) belong to Ascomycota phylum. Zygosaccharomycesrouxii was the most prevailed species accounting for 35.40% of the total population. Similarity percentage analysis revealed a low level of resemblance in species in each of the two Btana types (DBM: 17.26%, UBM: 16.87). According to HPLC analysis, lactate was detected in nine samples within a range of 0.87-23.06 g/100g. Culture plating and subsequent D1/D2 domain of 28s DNA analysis showed the prevalence of Z. rouxii. Fermentation of non-renewed date medium revealed a high ethanol production (21.31 ± 2.89 g/100g) by Lachanceathermotolerans and 5.87 g/100g of lactates by Kluyveromycesdelphensis. Enzymatic assay revealed a high esterase (C4) and naphtol-AS-BI-phosphohydrolase activity by L. thermotolerans, K. delphensis, and Pichiasubpelliculosa, while a high level of α-fucosidase was recorded for L. thermotolerans and P. subpelliculosa. The current results demonstrated that the traditional date product Btana is a promising source for yeasts useful in production of value-added products like bioethanol and lactic acid using low-income date cultivars.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The antimicrobial peptide oranicin P16 isolated from Trichosporon asahii ICVY021, found in camel milk's, inhibits Kocuria rhizophila

International audienceSix Trichosporon asahii strains designated ICVY021, ICVY022, ICVY023, ICVY024, ICVY025 and ICVY026 were isolated from camel milk and studied for their inhibitory activities against a large number of fungi and bacteria as target organisms. Only strain ICVY021 was able to inhibit Kocuria rhizophila CIP 53.45, through production of an extracellular heat-stable, proteinaceous antibacterial peptide, with partial amino acid sequences of PPFPK and CTHV(L/I)(K/Q) or TCHV(L/I)(K/Q), determined using LC/MS/MS. This peptide, named oranicin P16, was thought to impede the cell-division mechanism. The anti-K. rhizophila activity was confirmed, in situ , using skim milk as a food matrix. T. asahii ICVY021 did not show any hemolytic activity or any cytotoxicity effect against eukaryotic Caco-2 cells. T. asahii ICVY021 was sensitive to azoles antifungal compounds, but not to 5-fluorocytosine and anidulafungin

Exopolysaccharide produced by Weissella confusa: Chemical characterisation, rheology and bioactivity

International audienceThe purpose of this study was to characterise the production of exopolysaccharide (EPS) by indigenous lactic acid bacteria (LAB) isolated from traditional Algerian dairy products and to evaluate their possible use in agri-foods. Among the collection of isolated strains, the strain Weissella confusa (W4) was selected for its ability to produce EPS once exposed to a sucrose culture medium. EPS produced were first isolated with a standardised method and further characterised in terms of molecular size, antioxidant activity, and rheological properties. Its direct implication in the texture and syneresis of acid milk gel was evaluated offering interesting industrial applications for its use during processes dealing with dairy products