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The objective of this study was to investigate the effect of addition of sawdust co-composted with sewage sludge and wheat straw on seeds germination. Two mixtures were piled and composted over 90 days. The first mixture (C1) was composed of sewage sludge and wheat straw, while the second mixture (C2) was composed of sewage sludge, wheat straw and wood sawdust. The results showed that the physicochemical parameters of both composts, i.e., temperature (> 55 °C in the thermophilic phase), moisture content (~ 30%). pH (6.73 for C1 and 7.19 for C2) and EC values (1.81 mS cm−1 for C1 and 1.32 mS cm−1 for C2) reached the required maturity standard. The values of C/N were below 12 indicating a high degree of maturity. Also, no bacterial pathogens were detected in the final composts. The concentration of total heavy metals has been reduced allowing the elimination of sewage sludge toxicity, confirmed by the germination index, which reached over 80%. Strong positive correlations were noticed between total Kjeldahl nitrogen of C2 and germination indexes of all the studied species. The obtained results indicate that the addition of wood sawdust increases the nitrogen content leading to slightly alkaline compost which influences seeds germination by reducing the phytotoxicity of sewage sludge.

Breast-milk is an important source of bacteria for the colonization of the infant‘s gut. The aim of our study was to isolate and identify bacteria from samples of breast-milk of 32 women and from fecal samples of their breast-fed infants. Antimicrobial activity of isolates was also performed. A total of 155 isolates were characterized by phenotypic tests and identified by 16S rDNA sequencing analysis. The isolates belonged to 6 different species of acid lactic bacteria (LAB) and Staphylococcus epidermidis. Enterococcus faecium was the most frequently isolated species (40.8%) and faeces (42.5%). According to the mother’s lifestyle, we noticed that the genus Enterococcus was the most frequently isolated from rural mother’s milk as well as urban mother’s milk. Lactobacillus fermentum (P < 0.05) and Staphylococcus epidermidis (P < 0.01) were isolated only from rural mother’s milk. An antimicrobial activity was observed in 30 strains from 148 LAB, the higher level of antagonist was with E.faecium (35 mm). The observed results showed that the isolated strains from rural mother’s milk were different from that urban mother’s milk. Eventual studies can be carried out about lifestyle and nutrition of mothers to explain the effect on the flora found in the milk and feces infants.

The objective of this study was to isolate and select Lactobacillus strains with probiotic features for a potential use as starter for the preservation of animal feed. Olives, cow’s and camel’s milk, butter, beer drech and maize silage were used as isolation sources. Molecular identification using 16S rRNA gene sequencing identified four isolates of Lactobacillus plantarum and three of Lactobacillus fermentum. The different screening tests revealed that four strains: Lactobacillus plantarum OV13, Lactobacillus sp. OV15, Lactobacillus fermentum E161 and Lactobacillus sp. E631 are the best probiotic candidates , based on the results of their tolerance to acidic pH between 2 and 3.5, to 0.3% bile, to artificial gastric conditions for 18h of incubation , to their antibiotics resistance, their inhibition power on pathogenic bacteria (Pseudomonas sp., Staphylococcus aureus , Escherichia coli and Listeria ivanovii), and finally to their adhesion capacity to intestinal epithelial cells. The selected probiotic strains are considerate as good candidates for further investigation and should be tested, in vivo, to elucidate their potential health benefits on the animal performance as novel probiotic starters.

Plants live in association with complex populations of microorganisms, including Plant Growth-Promoting Rhizobacteria (PGPR) that confer to plants an improved growth and enhanced stress tolerance. This large and diverse group includes endophytic bacteria that are able to colonize the internal tissues of plants. In the present study, we have isolated a nonrhizobial species from surface sterilized root nodules of Retama monosperma, a perennial leguminous species growing in poor and high salinity soils. Sequencing of its genome reveals this endophytic bacterium is a Bacillus megaterium strain (RmBm31) that possesses a wide range of genomic features linked to plant growth promotion. Furthermore, we show that RmBm31 is able to increase the biomass and positively modify the root architecture of seedlings of the model plant species Arabidopsis thaliana both in physical contact with its roots and via the production of volatile organic compounds. Lastly, we investigated the molecular mechanisms implicated in RmBm31 plant beneficial effects by carrying out a transcriptional analysis on a comprehensive set of phytohormone-responsive marker genes. Altogether, our results demonstrate that RmBm31 displays plant growth-promoting traits of potential interest for agricultural applications.

In the present investigation, six Rhizobium strains isolated from Algerian soil were checked for their antimicrobial activity against Pseudomonas savastanoi, the agent responsible for olive knot disease. Rhizobium sp. ORN 24 and ORN 83 were found to produce antimicrobial activities against Pseudomonas savastanoi. The antimicrobial activity produced by Rhizobium sp. ORN24 was precipitable with ammonium sulfate, between 1,000 and 10,000 KDa molecular weight, heat resistant but sensitive to proteases and detergents. These characteristics suggest the bacteriocin nature of the antimicrobial substance produced by Rhizobium sp. ORN24, named rhizobiocin 24. In contrast, the antimicrobial activity produced by Rhizobium sp. ORN83 was not precipitable with ammonium sulfate; it was smaller than 1,000 KDa molecular weight, heat labile, and protease and detergent resistant. These characteristics could indicate the relationship between the antimicrobial substance produced by Rhizobium sp. ORN 83 and the “small” bacteriocins described in other rhizobia.

The aim of this research was to evaluate some technological traits of L. plantarum strains previously isolated from fermented olives. For this purpose, 11 strains were tested for their in vitro antibiotic susceptibility, resistance to low pH values, acidifying activity, proteolytic activity, haemolytic activity, lactic acid and exopolysaccharide production and resistance to freeze-drying .Collectively, the strains were susceptible to most of the antibiotics tested and showed survival at pH 2. Most strains showed high (1.035 ± 0.29 to 0.912 ± 0.21 mmol/l ± sd of lactic acid) or medium (0.556 ± 0.29 to 0.692 ± 0.18 mmol/l ±sd) acidification activity with good proteolytic activity (1.49 ± 0.25 to 5.25 ± 0.11 mg L-1 tyrosine). None of the strains produced exopolysaccharides or haemolysis in sheep's blood.El objetivo de esta investigación fue evaluar algunos aspectos tecnológicos de cepas de L. plantarum previamente aisladas de aceitunas fermentadas. Para este propósito, 11 cepas fueron usadas para estudiar su susceptibilidad a antibióticos in vitro, resistencia a valores de pH bajos, actividad acidificante, proteolítica, y hemolítica, producción de ácido láctico y exopolisacáridos, y resistencia a la liofilización. En general, las cepas fueron susceptibles a la mayoría de los antibióticos ensayados y mostraron supervivencia a pH 2. La mayoría de las cepas mostraron una actividad de acidificación alta (1.035 ± 0.29 a 0.912 ± 0.21 mmol/l de ácido láctico) o media (0.556 ± 0.29 a 0.692 ± 0.18 mmol/l) con una buena actividad proteolítica (1.49 ± 0.25 a 5.25 ± 0.11 mg L-1 tirosina). Ninguna de las cepas produjo exopolisacáridos o hemolisis en sangre de oveja.

Microorganisms (aerobic bacteria, coliforms, lactic acid bacteria, psychrotrophs, lipolytic bacteria and yeasts) were isolated from 20 samples of shmen, a traditional clarified butter made from sour camel milk in the Algerian Sahara. The values of pH, titratable acidity, NaCl, total solid, moisture, and fat content ranged from : 3.11-4.97, 0.19-0.36%, 1.04-2.15%, 64.03-65.11%, 34.40-34.99%, and 49.90-56% respectively. A total of 181 isolates of lactic acid bacteria were identified as Lactobacillus plantarum (40 strains), Lactobacillus delbrueckii ssp. bulgaricus (35 strains), Lactococcus lactis ssp. lactis biovar diacetylacti (22 strains), Lactococcus lactis ssp. cremoris (18 strains), Lactobacillus paracasei ssp. paracasei (10 strains), Leuconostoc pseudomesenteroides (9 strains) and Leuconostoc gelidum (12 strains) Enterococcus faecium (35 strains). Yeasts were isolated from all samples (55 isolates). Of these, 40 were identified as Saccharomyces cerevisiae and 15 isolates were identified as Saccharomyces sp.Se aislaron los microorganismos (bacterias aeróbicas, coliformes, bacterias acido lácticas, bacterias lipolíticas y levaduras) de 20 muestras de “shmen”, una matequilla tradicional del Sahara argelino hecha a partir de leche de camella. Los valores de pH, acidez, libre, Nacl, solidos totales, humedad y grasa oscilaron entre 3,11-4,97, 0,19-0,36%, 1.04-2,15%, 64,03-65,11%, 34,40-34,99% y 49,90-56,00%, respectivamente. Entre los 181 cultivos puros de bacterias lácticas se identificaron Lactobacillus plantarum (40 cepas), Lactobacillus delbrueckii ssp. bulgaricus (35 cepas), Lactococcus lactis ssp. lactis biovar diacetylacti (22 cepas), Lactococcus lactis ssp. cremoris (18 cepas), Lactobacillus paracasei ssp. paracasei (10 cepas), Leuconostoc pseudomesenteroides (9 cepas) and Leuconostoc gelidum (12cepas) Enterococcus faecium (35 cepas). Asimismo, se detectaron levaduras en todas las muestras (55 cultivos puros). De estos, 40 se identificaron como Saccharomyces cerevisiae y 15 como Saccharomyces sp.

The photoinactivation of the Escherichia coli bacteria with the pulsed dielectric barrier discharge excilamp krypton chorine (KrCl) emitted at 222 nm is presented. The Escherichia coli, with the initial density of 34.106 colony forming units (CFU)/?L, has been irradiated in the aqueous and on the surface medias, respectively. A high reduction rate in the survival density of E. coli has been reached by the photoinactivation in both media during the first 30 s. The photoinactivation resulted in the logarithmic reduction factor of 5.6 log and 5.1 log within irradiation time of 30 s on the surface and in the aqueous medias, respectively. At the high dose of 2880 mJ/cm2 , the logarithmic reduction factor reached 6.1 log and 5.5 log on the surface and in the aqueous medias, respectively. The first tailing plateau was appeared on the surface and in the aqueous medias at 60 and 300 s of irradiation time, respectively.

Previously 12 Lactobacillus plantarum strains were isolated from fermented olives. Among these, only L. plantarum OL15 produced bacteriocin (plantaricin OL15). In this study, the 12 strains were examined for plasmid DNA content. Of these, 9 strains have shown one to three plasmid bands ranging in size from 5.4 to 12.2 kb. L. plantarum OL15 exhibited one plasmid (9.6 kb) which was named pOL15. After curing with novobiocin and ethidium bromide, the plasmid profile analysis of non producing derivatives, showed that the 9.6 kb plasmid pOL15 harbored by the parental strain had been lost in all cases and none of them regained the ability to produce plantaricin OL15 suggesting that the production of plantaricin OL15 is plasmid linked. Plantaricin OL15 was not inactived by amylase and lipase suggesting that plantaricin OL15 activity was not dependent on the presence of either a carbohydrate or lipid moiety. Plantaricin OL15 showed activity against lactic acid bacteria of different species and also against olive spoilage and phytopathogenic bacteria, including Pseudomonas and Erwinia. En un estudio previo, se aislaron 12 cepas de Lactobacillus plantarum a partir de aceitunas fermentadas. Entre ellas, solo L. plantarum OL15 produjo bacteriocinas (plantaricin OL15). En este estudio, se examinó el contenido de AND plásmido en las 12 cepas citadas. Entre ellas, 9 cepas han mostrado de una a tres bandas de plásmido con tamaños en el rango de 5.4 a 12.2 kb. L. plantarum OL15 exhibió un plásmido (9.6 kb) que se denominó pOL15. Después del curado con novobiocina y bromuro de etidio, la pérdida del plásmido pOL15 asociada a la pérdida de su facultad para producir plantaricin OL15, sugiere que la producción de plantaricina OL15 está ligada al plásmido. La plantaricin OL15 no se inactivó por amilasa ni por lipasa sugiriendo que su actividad no es dependiente de la presencia de carbohidratos o lípidos. La plantaricina OL15 mostró actividad frente a bacterias lácticas de diferentes especies y también frente a residuos de aceitunas y bacterias fitopatogénicas, incluyendo Pseudomonas y Erwinia.

The microflora of naturally fermented green olives produced in Western Algeria was studied over 15, 60 and 90 day fermentation periods. Different microorganisms (aerobic bacteria, coliforms, staphylococci, lactic acid bacteria, lactobacilli, enterococci, yeasts, psychrotrophs and lipolytic bacteria) were recorded at 15 and 60 days of fermentation. After 90 days (pH 4.40) of fermentation, the lactic acid bacteria population became dominant and persisted together with yeasts throughout the fermentation period. The lactic acid bacteria isolated (343 isolates) were identified as L. casei, L. rhamnosus, L. paracasei, L. plantarum, L. lactis subsp. lactis, E. faecalis, E. faecium and E. durans. The dominant species was L. plantarum. Yeasts were isolated from all samples (32 isolates) and were identified as Saccharomyces cerevisiae or Candida parapsilosis. Also, in this study we reported that brine solutions obtained at the end of olive fermentation were able to stimulate the growth of several L. plantarum strains La microflora de las aceitunas verdes fermentadas naturalmente elaboradas en Argelia Occidental fue estudiada en períodos de fermentación de 15, 60 y 90 días. Diferentes microorganismos (bacterias aeróbicas, coliformes, estafilococos, bacterias del ácido láctico, lactobacilos, enterococos, levaduras, psicotrofos y bacterias lipolíticas) fueron detectados a los 15 y 60 días de fermentación. Después de 90 días de fermentación (pH 4.40), la población de bacterias lácticas se hizo dominante y persistió junto con las levaduras a lo largo de todo el proceso. Las bacterias lácticas aisladas (343) fueron identificadas como L. casei, L. rhamnosus, L. paracasei, L. plantarum, L. lactis subsp. lactis, E. faecalis, E. faecium y E. durans. La especie dominante fue L. plantarum. Las levaduras aisladas (32) de todas las muestras fueron identificadas como Saccharomyces cerevisiae o Candida parapsilosis. También se recoge en este estudio que las soluciones de salmuera obtenidas al final de fermentación de aceitunas verdes fueron capaces de estimular el crecimiento de varias cepas de L. plantarum.

Microorganisms (aerobic bacteria, coliforms, lactic acid bacteria, psychrotrophs, lipolytic bacteria and yeasts) were isolated from 20 samples of shmen, a traditional clarified butter made from sour camel milk in the Algerian Sahara. The values of pH, titratable acidity, NaCl, total solid, moisture, and fat content ranged from : 3.11-4.97, 0.19-0.36%, 1.04-2.15%, 64.03-65.11%, 34.40-34.99%, and 49.90-56% respectively. A total of 181 isolates of lactic acid bacteria were identified as Lactobacillus plantarum (40 strains), Lactobacillus delbrueckii ssp. bulgaricus (35 strains), Lactococcus lactis ssp. lactis biovar diacetylacti (22 strains), Lactococcus lactis ssp. cremoris (18 strains), Lactobacillus paracasei ssp. paracasei (10 strains), Leuconostoc pseudomesenteroides (9 strains) and Leuconostoc gelidum (12 strains) Enterococcus faecium (35 strains). Yeasts were isolated from all samples (55 isolates). Of these, 40 were identified as Saccharomyces cerevisiae and 15 isolates were identified as Saccharomyces sp. Se aislaron los microorganismos (bacterias aeróbicas, coliformes, bacterias acido lácticas, bacterias lipolíticas y levaduras) de 20 muestras de “shmen”, una matequilla tradicional del Sahara argelino hecha a partir de leche de camella. Los valores de pH, acidez, libre, Nacl, solidos totales, humedad y grasa oscilaron entre 3,11-4,97, 0,19-0,36%, 1.04-2,15%, 64,03-65,11%, 34,40-34,99% y 49,90-56,00%, respectivamente. Entre los 181 cultivos puros de bacterias lácticas se identificaron Lactobacillus plantarum (40 cepas), Lactobacillus delbrueckii ssp. bulgaricus (35 cepas), Lactococcus lactis ssp. lactis biovar diacetylacti (22 cepas), Lactococcus lactis ssp. cremoris (18 cepas), Lactobacillus paracasei ssp. paracasei (10 cepas), Leuconostoc pseudomesenteroides (9 cepas) and Leuconostoc gelidum (12cepas) Enterococcus faecium (35 cepas). Asimismo, se detectaron levaduras en todas las muestras (55 cultivos puros). De estos, 40 se identificaron como Saccharomyces cerevisiae y 15 como Saccharomyces sp.

Lactobacillus plantarum OL15 previously isolated from Algerian fermented green olives produces antimicrobial conpounds in its culture medium. Inhibitory action against other strains of Lactobacillus, Lactococcus , and Propionibacterium was observed . Activity was completely or partially inactivated by proteolytic enzymes, stable at pH values ranging from 3.0 to 8.0, and heat stable even after autoclaving at 121 °C for 15 min. The bacteriocin activity was able to pass through cellulose membranes with 100,000 but not through 10,000 molecular weight cut-off.Lactobacillus plantarum OL15, aislado de aceitunas verdes argelinas, produce un compuesto antimicrobiano en el medio de cultivo, observándose un efecto inhibidor frente a otras cepas de Lactobacillus, Lactococcus y Propionibacterium . Dicha actividad desaparece completa o parcialmente después del tratamiento con enzimas proteolíticas, es estable al pH en el rango de 3,0 a 8,0 y es, asimismo estable al calor incluso después de someterla a un proceso térmico de 121 ºC durante 15 minutos. La bacteriocina pasa a través de membranas de celulosa de corte molecular de 1000.000 pero no a través de las de 10.000.

This study was undertaken with the aim of obtaining lactic acid bacteria with the ability to ferment olives for possible use as starter cultures. For this reason, 32 isolates of lactic acid bacteria isolated from the spontaneous fermentation of green olives were characterized and identified on the basis of morphological and biochemical criteria. 14 of them were identified as Lactococcus lactis, 11 isolates as Lactobacillus plantarum and 7 isolates as Enterococcus sp. Of the 18 isolates examined for antagonistic activity, 3 isolates of Lactobacillus plantarum and one isolate of Enterococcus sp. were able to give distinct zones of inhibition against 5 indicator strains of lactic acid bacteria isolated in this study. Cell free supernatant of Lactobacillus plantarum OL9 was active against Gram-positive bacteria (Lactobacillus, Enterococcus and Propionibacterium) and also against one Gram-negative bacteria strain of spoilage significance (Erwinia). Este estudio se emprendió con el objetivo de obtener bacterias del ácido láctico con capacidad para utilizarse como cultivo iniciador en la fermentación de aceitunas. Por esta razón, 32 cepas de bacterias del ácido láctico procedentes de fermentaciones espontáneas de aceitunas verdes se caracterizaron e identificaron en función de criterios morfológicos y bioquímicos. Catorce cepas se identificaron como Lactococcus lactis, 11 cepas como Lactobacillus plantarum y 7 cepas como Enterococcus sp. De las 18 cepas que se examinaron para detectar actividades antagónicas, se encontró que 3 cepas de Lactobacillus plantarum y una de Enterococcus sp. mostraban zonas de inhibición contra 5 cepas indicadoras de bacterias del ácido láctico aisladas en este estudio. El sobrenadante libre de células Lactobacillus plantarum OL9 fue activo contra diversas bacterias Gram-positivas (Lactobacillus, Enterococcus y Propionibacterium) y contra una cepa de bacteria Gram-negativa relacionada con alteraciones (Erwinia).