Nutritional requirements for the production of dithiolopyrrolone antibiotics by Saccharothrix algeriensis NRRL B-24137

The amino acid and humic acid requirements of Saccharothrix algeriensis NRRL B-24137 for growth and production of the dithiolopyrrolone antibiotics were studied in a semi-synthetic medium (SSM). Nature and concentration of amino acids and humic acid strongly influenced the growth and dithiolopyrrolone specific production. The highest value of thiolutin (acetyl-pyrrothine) specific production was obtained in the presence of 1 g/l humic acid (336 mg/g DCW), and in the presence of 5mM l-cystine (309 mg/g DCW) as compared to 19 mg/g DCW obtained with the control. Furthermore, thiolutin production was increased about six-fold, four-fold and three-fold in the presence of l-proline, l-glutamic acid and dl-histidine, respectively. In contrast,the production of thiolutin was reduced by addition of other amino acids such as l-glutamine, dl-ethionine, l-methionine and l-arginine. The highest value of isobutyryl-pyrrothine production was obtained in the presence of 2,6-diaminopimelic acid and l-lysine (7.8 and 1.0 mg/g DCW, respectively). However, the highest value of butanoyl-pyrrothine production was obtained in the presence of humic acid (6.6 mg/g DCW), followed by l-cysteine and l-proline (3.6 and 3.2 mg/g DCW, respectively). In addition, the maximum specific production of senecioyl-pyrrothine (29 mg/g DCW) and tigloyl-pyrrothine (21 mg/g DCW) was obtained in the presence of humic acid. We found that, except for isobutyryl-pyrrothine, production of all dithiolopyrrolones was favoured by addition of l-proline. The maximum specific production was obtained with l-proline at concentrations of 2.50mM for thiolutin (133mg/gDCW),1.25mMfor senecioyl-pyrrothine, tigloyl-pyrrothine and butanoyl-pyrrothine production (29, 23 and 3.9 mg/gDCW, respectively). Production of all dithiolopyrrolones strongly decreased as the l-methionine or dl-ethionine concentration was increased in the culture medium

Aspergillus section Flavi and aflatoxins in Algerian wheat and derived products

Wheat and its derivatives are a very important staple food for North African populations. The aim of this study was to analyze populations of Aspergillus section Flavi from local wheat based on aflatoxins (AFs),cyclopiazonic acid (CPA) and sclerotia production, and also to evaluate AFs-contaminated wheat collected from two different climatic regions in Algeria. A total of 108 samples of wheat were collected during the following phases: pre-harvest, storage in silos and after processing. The results revealed that among the Aspergillus species isolated, those belonging to section Flavi were predominant. Of the 150 strains of Aspergillus section Flavi isolated, 144 were identified as Aspergillus flavus and 6 as Aspergillus tamarii. We showed that 72% and 10% of the A. flavus strains produced AFs and CPA, respectively. Among the 150 strains tested, 60 produced amounts of AFB1 ranging from 12.1 to 234.6 lg/g of CYA medium. Also, we showed that most strains produced large sclerotia. AFB1was detected by HPLC in 56.6% of the wheat samples and derived products (flour, semolina and bran) with contamination levels ranging from 0.13 to 37.42 lg/kg

Lifecycle Based Modeling of Smart City Ecosystem

International audienceSmart city services have an inevitable role in addressing the complexity of modern city operation. Smart transport, smart parking, smart energy, smart water and many others are examples of vertical smart city systems that are mainly concerned with its particular domain. Realizing the full promise of smart city will require interoperability among those systems and data fusion between heterogeneous components from different domains. In this regard, many standardization organizations have been working on modeling smart city and similar or related systems and concepts, such as Internet of Things (IoT) and Cyber Physical Systems (CPS), to ensure common technical grounding and architectural principles. Though, there is still a need to address the higher-level requirements of smart city as a complete ecosystem. To this end, this paper discusses different Smart City solutions and highlights lifecycle based modeling to better integrate people, processes, and systems; and assure information consistency, traceability, and long-term archiving

A Study of Western Expatriates Performance in Algeria: The Role of Cultural Intelligence

consistently suggests that expatriates on assignment require a great deal of support to adjust to their new environment. The cultural environment in which expatriate operate is an important factor for determining successful performance.  The cornerstone of this study is to investigate the influence of dynamic intercultural competency of Cultural Intelligence (CQ) and its dimensions on expatriate job performance.  Analyzing 332 expatriate residing and working in Algeria using Hierarchical regression, we found that Cultural Intelligence (CQ) is a vital intercultural competency that facilitates expatriate job performance in international assignments.  Further, we demonstrated that expatriate in Algeria with greater metacognitive and behavioral CQ fared better in their contextual performance.  Greater assignment specific performance related to greater behavioral CQ. Keywords: Cultural intelligence, Expatriate, Job Performance, Algeria.         تهدف هده  الدراسة  الى التعرف على طبيعة العلاقة بين الذكاء الثقافي وأبعاده و الأداء  الوظيفي للمغتربين العاملين في الشركات المتعددة الجنسيات    في الجزائر.  الابحاث السابقة على المغتربين تقترح دائما و باستمرار ان المغتربين في مهامهم الوظيفية بحاجة الى قدر كبير من الدعم للتأقلم مع بيئتهم الجديدة.  البيئة التي يعمل فيها المغتربين هي عامل مهم لتحديد الاداء الوظيفي الناجح.هدفت هده الدراسة الى التعريف بمفهوم الذكاء الثقافي و تأثيره على الأداء  الوظيفي على عينة من المغتربين الأجانب والتي بلغ حجمها 332 فردا مقيما ويعمل في الجزائر وهي البيئة المخالفة للبيئة الاصلية للمغتربين.  بنية الدراسة على فرضية رئيسية  مفادها׃هناك علاقة ارتباط إيجابية بين ابعاد الذكاء الثقافي(المعرفة, الدافعية والسلوك) وابعاد الأداء  الوظيفي(أداء المهمة, الأداء السياقية, و أداء المهمة المحددة).­وتم تحليل البيانات باستخدام الاساليب الاحصائية: معامل الارتباط البسيط والانحدار الهرمي و توصلت  الدراسة الى مجموعة من الاستنتاجات أهمها:وجود علاقة ذات دلالة احصائية بين الذكاء الثقافي بأبعاده الاربعة و فعالية الاداء الوظيفي بأبعاده الثلاثة. وفي ضوء هذه الاستنتاجات فقد اقترحت الدراسة مجموعة من التوصيات أهمها:ان الذكاء الثقافي هو كفاءة أساسية للتفاعل بين الثقافات او القدرة على التواصل الناجح بين ابناء ثقافة مختلفة والذي يسهل الأداء الوظيفي للمغتربين في المهام الدولية

Actinopolyspora saharensis sp. nov., a novel halophilic actinomycete isolated from a Saharan soil of Algeria

A novel halophilic actinomycete, strain H32T,was isolated froma Saharan soil sample collected in El-Oued province, south Algeria. The isolate was characterized by means of polyphasic taxonomy. Optimal growth was determined to occur at 28–32°C, pH 6.0–7.0 and in the presence of 15–25 %(w/v) NaCl. The strain was observed to produce abundant aerial mycelium, which formed long chains of rod-shaped spores at maturity, and fragmented substrate mycelium. The cell wall was determined to contain meso-diaminopimelic acid and the characteristic whole-cell sugars were arabinose and galactose. The predominant menaquinoneswere found to beMK-10(H4) andMK-9(H4). The predominant cellular fatty acids were determined to be anteiso C17:0, iso-C15:0 and iso-C16:0. The diagnostic phospholipid detected was phosphatidylcholine. Phylogenetic analyses based on the 16S rRNA gene sequence showed that this strain formed a distinct phyletic line within the radiation of the genus Actinopolyspora. The 16S rRNAgene sequence similarity indicated that strain H32T was most closely related to ‘Actinopolyspora algeriensis’ DSM 45476T (98.8 %) and Actinopolyspora halophila DSM 43834T (98.5 %). Furthermore, the result of DNA–DNA hybridization between strain H32T and the type strains ‘A. algeriensis’ DSM45476T, A. halophila DSM 43834T and Actinopolyspora mortivallis DSM 44261T demonstrated that this isolate represents a different genomic species in the genus Actinopolyspora. Moreover, the physiological and biochemical data allowed the differentiation of strain H32T from its closest phylogenetic neighbours. Therefore, it is proposed that strain H32T represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora saharensis sp. nov. is proposed. The type strain is H32T (=DSM 45459T=CCUG 62966T)

Pressurized Liquid Extraction for the Recovery of Carotenoids and Functional Compounds from Green and Orange Dunaliella salina Biomasses

In recent years, intensive research has been conducted on natural carotenoids extraction using several processes. Conventional extraction methods require high amounts of solvents and a long extraction time. However, pressurized liquid extraction demonstrated to be an interesting method. The extraction efficiencies of pressurized liquid for the recovery of carotenoids, from the green and the orange biomasses of the microalga Dunaliella salina DunaDZ1, are described. Organic solvents were tested including ethanol, n-hexane, ethyl acetate and a mixture of n-hexane:ethanol (3:4). Moreover, three extraction temperatures were used (90, 120 and 150 °C) at constant pressure. Extraction efficiency and extracts characterization were conducted. Results have shown that temperature has a positive effect on extraction yield. HPLC characterization showed that β-carotene is the main carotenoid in the orange biomass, and lutein in the green biomass, with the presence of other minor carotenoids in both biomasses. The highest carotenoid amounts were found in the n-hexane orange biomass extract, with β-carotene isomers as the main carotenoid (138.54 and 357.10 mg/g of dry extract, for cis and trans isomers, respectively). Otherwise, extracts obtained at the lowest tested temperature provided the best carotenoid yields. The best results for the antioxidant activity were obtained at 120 °C for orange biomass ethyl acetate extract

Kinetic study of the growth of Saccharothrix algeriensis DSM 44581 in batch fermenter on a semi-synthetic medium in the presence of tiglic acid and methacrylic acid

This work aimed to investigate the effect of some nutriments (tiglic acid and methacrylic acid) on the growth of Saccharothrix algeriensis DSM 44581 on chemically defined medium (semi-synthetic medium) by using controlled batch fermenters. The controlled batch fermentations were conducted in the presence of tiglic and methacrylic acids. The growth rate of S. algeriensis in all fermentations was fast during the first 10 h of fermentation. The control culture showed a partially cell lysis in comparison to cultures with organic acids. This result showing that these organic acids could be used for biomass maintaining. The formation of biomass was influenced by the addition of organic acids. The experiment in the fermentor showed some differences with results obtained in Erlenmeyers

Actinopolyspora righensis sp. nov., a novel halophilic actinomycete isolated from Saharan soil in Algeria

A novel halophilic actinomycete strain, H23T, was isolated from a Saharan soil sample collected in Djamaˆa (Oued Righ region), El-Oued province, South Algeria. Strain H23T was identified as a member of the genus Actinopolyspora by a polyphasic approach. Phylogenetic analysis showed that strain H23T had 16S rRNA gene sequence similarities ranging from 97.8 % (Actinopolyspora xinjiangensis TRM 40136T) to 94.8 % (Actinopolyspora mortivallis DSM 44261T). The strain grew optimally at pH 6.0–7.0, 28–32°C and in the presence of 15–25 % (w/v) NaCl. The substrate mycelium was well developed and fragmented with age. The aerialmyceliumproduced long, straight or flexuous spore chains with non-motile, smooth-surfaced and rod-shaped spores. Strain H23T had MK-10 (H4) and MK-9 (H4) as the predominant menaquinones. The whole microorganism hydrolysates mainly consisted of meso-diaminopimelic acid, galactose and arabinose. The diagnostic phospholipid detected was phosphatidylcholine. The major cellular fatty acids were anteiso-C17:0 (37.4 %), iso-C17:0 (14.8 %), iso-C15:0 (14.2 %), and iso-C16:0 (13.9 %). The genotypic and phenotypic data show that the strain represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora righensis sp. nov. is proposed, with the type strain H23T (=DSM 45501T = CCUG 63368T = MTCC 11562T)

A new dithiolopyrrolone antibiotic triggered by a long fermentation of Saccharothrix algeriensis NRRL B‐24137 in sorbic acid‐amended medium

Saccharothrix algeriensis NRRL B‐24137 is an actinobacterium isolated from Algerian Saharan soil. It produces bioactive compounds belonging to the dithiolopyrrolone class of antibiotics, which are characterized by the possession of a unique pyrrolinonodithiole nucleus. Dithiolopyrrolones are known for their strong antibacterial and antifungal activities. This class of antibiotics generated great interest after the discovery of their anticancer properties. In this study, an antibiotic named PR11, produced after a long bacterial fermentation (11 days) in sorbic acid‐containing culture broth, was characterized as a new dithiolopyrrolone derivative. After HPLC analysis and purification, the chemical structure of this antibiotic was determined by 1H‐ and 13C‐nuclear magnetic resonance, mass and UV‐visible data. PR11 was thus characterized as an iso‐hexanoyl‐pyrrothine, a novel dithiolopyrrolone derivative. The minimum inhibitory concentrations of the new induced antibiotic were determined against several pathogenic micro‐organisms. A moderate to strong activity was noted against all Gram‐positive bacteria, filamentous fungi and yeasts tested

Effective biosynthesis of benzoyl-pyrrothine dithiolopyrrolone antibiotic by cinnamic acid-precursor addition in culture of Saccharothrix algeriensis NRRL B-24137

Dithiolopyrrolone antibiotics, produced by several micro‐organisms, are known for their strong antimicrobial and antitumor activities. Among of this micro‐organisms, Saccharothrix algeriensis NRRL B‐24137, a rare actinobacterium, has the ability to produce several dithiolopyrrolones derivatives depending on precursors added in the culture medium. After 10 days of strain fermentation on semi‐synthetic medium supplemented with cinnamic acid and HPLC purification, biosynthesis of benzoyl‐pyrrothine dithiolopyrrolone was evidenced through complete spectroscopic (UV–visible and 1H and 13C NMR) and spectrometric (electron impact mass spectrum) analyses. The pure molecule showed appreciable minimum inhibitory concentration values against several Gram‐positive bacteria and filamentous fung