Proteases are the most important industrial enzymes and widespread in nature. In the present work, sardine waste (viscera) was used to optimize the protease production by newly isolated Streptomyces sp. strain. A comparative study of proteolytic activity was first carried out on a synthetic medium, sardine waste broth (in submerged fermentation), and powder of the same waste (in solid-state fermentation). The enzyme production media were optimized according to statistical methods, while using two plans of experiences. The first corresponded to the Plackett-Burman matrices and the second was the Box-Wilson central composite design. The protease characteristics study showed an optimum temperature of 40 degrees C and an optimum pH of 7, which is a typical characteristic of neutral proteases. The results of protease production optimization showed maximum activity on the following fermentation medium: sardine viscera broth (25%), NaCl (7.99 g/L), and gelatin (9.82 g/L). All these results confirmed the high biotechnological potential of this strain for neutral protease production on sardine viscera, which provides an interesting and promising strategy for large-scale enzyme production on fish waste.

Cereals are an important part of staple foods all over the world, and their fermentation is an age-old technique to obtain desired food products. Cereal-based foods have been widely consumed for thousands of years as a major source of nutrients, particularly in developing and overpopulated countries, and in Africa they represent a major source of nutrients and energy. Thus, the main aim of this review is a focus on cereal-based and fermented foods from Africa, with a special emphasis on the most important keywords and topics of the literature, microbiota, as well as on the nutritional side, to provide evidence on the importance of these products as sources of functional microorganisms, and/or starter cultures.

Agro-industrial residues represent valuable resources that can meet microorganism’s requirements for growth and metabolite production. The goal of the present study is to formulate an optimum submerged fermentation medium for a newly isolated strain of Streptomyces sp. PO3, utilizing wheat bran as the base medium. Initially, the optimal pH, temperature, and wheat bran concentration were determined using the “one variable at a time” method. Subsequently, to enhance production efficiency, additional components were tested using multifactorial statistical approaches. The optimal conditions affecting protease production were determined by a central composite design. Kinetic production was monitored on the optimized medium for 216 h. The highest protease production was achieved through submerged fermentation at pH 9.0, 40 °C, and 25

An actinobacteria strain was isolated from an olive waste mill and tested for protease production on skimmed milk media. The strain identification was achieved through both 16 S rDNA sequencing and phenotypic characterization. The enzyme was purified using the ammonium sulfate/t-butanol three-phase partitioning (TPP) method, followed by characterization to investigate the effect of pH, temperature, and various chemical agents. Subsequently, the enzyme was assessed for its milk coagulation activity. The strain belonging to the Streptomyces genera, exhibits significant phylogenetic and phenotypic differences from the aligned species, suggesting its novelty as a new strain. The enzyme was best separated in the TPP aqueous phase with a 5.35 fold and 56.25

Screening of new producing strains is required to meet the constant industrial demand for useful enzymes. In this context, an actinobacteria was isolated from the olive pomace, tested for extracellular lipase production, and identified by partial 16S rDNA sequencing. Then, the physicochemical characteristics of the enzyme are determined. Strain is a member of Streptomyces genus. Lipase was partially purified at 62.5 times, with a yield of 14.83% and a specific activity of 337.5 U/mg. Optimum activity was achieved at pH 7.0 and 60 degrees C; it was completely preserved at pH 6.0 to 9.0, and more than 70% at 40 to 70 degrees C, after 1 hour. The metal ions: K+, Na+, Ca2+, Co2+, Cu2+, Fe2+, Mg2+, Mn2+, and Zn2+ had no significant impact. Lipase activity was stable with ethylene diamine tetra acetic acid (EDTA), sodium dodecyl sulfate (SDS), H2O2, Triton x100, and Tween 80. Moreover, it was enhanced in butanol, chloroform, ethyl acetate, isopropanol, isobutyl acetate, hexane, petrol ether, and toluene. This enzyme can be suitable for various industrial applications.

Proteases are a group of enzymes that catalyse the degradation of proteins resulting in the production of their amino acid constituents. In the present study newly isolated Streptomyces sp. was subjected to produce proteases through solid state fermentation while wheat bran was used as substrate. To produce proteases, a local strain Streptomyces sp. was isolated from a soil sample of Ezzemouls saltpan, located in Ain M'lila (East of Algeria). The phenotypic and phylogenetic studies of this strain showed that it represents probably a new species. The SSF production medium for Streptomyces sp. was optimized using Plackett and Burman statistical methods. The results showed a maximum activity on basal wheat bran medium supplemented with 1% fructose. The best SSF humidifying solution was pH 9.0 phosphate buffer at 50% moisture. Protease has an optimum at pH 7.0, which is a typical characteristic of neutral proteases. The optimum temperature was 60°C and proved stable up to 80°C. The results showed that the novel Streptomyces sp. isolate is a good producer of extracellular neutral protease on wheat bran, which can be beneficial for industries. J. Bio-Sci. 29(1): 33-48, 2021 (June)

Actinomycetes are an uncommon agent of human infections and its pathogenic factors are not known. The present study reports a rare case isolation of an actinomycete from a woman pleural fluid; the strain was identified by 16S rRNA gene sequence analysis. This strain was tested to produce an extracellular protease that hydrolysis gelatin, casein and hemoglobin on agar mediums. The purification of the enzyme was carried by ammonium sulfate precipitation, gel filtration and ion exchange chromatographies. The activity of protease was studied at different pH values and temperatures and in the presence of metallic ions and inhibitors. The molecular weight of the enzyme was determined by 12% Tricine SDS-polyacrylamide gel electrophoresis. The strain was identified as Streptomyces cinereoruber ssp. cinereoruber. Extracellular proteolytic enzyme was purified at 19.67 fold and a 3.0% recovery. The enzyme was characterized as having optimal activities at pH 11.0 and 50°C, it keeps more than 50% of activity at pH between 4.0 to 12.0 and it is thermostable at 30 and 40°C. Enzymatic activity is enhanced in the presence of metal ions and inhibited by EDTA and 1,10-phenanthroline. The molecular weight was 53 kDa. This study reports the first case isolation of Streptomyces cinereoruber ssp. cinereoruber from pleural fluid, the extracellular zinc-metalloprotease was proposed as candidate virulence factor.

Objective: Many immunomodulators have also been discovered among the primary metabolites of microorganisms, such as cell wall components. In the present study, the immunomodulatory effect of intracellular lectin extract from Micromonospora aurantica GF44c strain was evaluated in vivo. Methods: The immunomodulatory potential of intracellular lectin on the phagocytic activity was measured by the carbon clearance rate test, at different doses (30, 50, and100 mg/kg) respectively. Results: Micromonospora aurantica lectin extract increased significatively the phagocytic activity in when compared with the control and thus the clearance rate of carbon was faster after the administration of the actinomycete extract P<0.05. Conclusion: From the above findings, it is concluded that intracellular lectin extract possesses potential for augmenting activity of reticuloendothelial system more at high dose (500 mg/kg). keywords: Immunostimulation, Actinomycete, Micromonospora aurantica, lectin, Phagocytic activity , Carbon

The aim of this study was to identify aerobic actinomycetes strains belonging to genera and species rarely encountered in infections. Clinical specimens (sputum, gastric fluid and abscess pus) are collected from patients with symptoms of tuberculosis, pneumopathy, septicemy or having abscess, hospitalized in different services of infectious diseases in Constantine University Hospital Center, East of Algeria. A total of 49 strains of aerobic actinomycetes were isolated; among which 40 ones belong toStreptomyces, Nocardia and Actinomadura genera; however, nine strains are members of other actinomycetes genera, characterized in this study. Phenotypic, chemotaxonomic proprieties and sequencing 16S rRNA gene established identification of these isolates to:Nonomuraea roseola, Kribbella sp., Micromonospora aurantiaca, Nocardiopsissynnemataformans and Saccharothrix longispora. Identified isolates belonged to genera and species rarely encountered in clinical specimens; their role in pathology must be defined. Key words: Uncommon aerobic actinomycetes, clinical specimens, polyphasic taxonomy.

In the search for new antibiotics from Steptomyces, investigating extremes habitats enhances the probability of isolating novel producers. In this context, the antibacterial activity of four Streptomyces strains isolated from Ezzmoul saltpans was studied. Two of them showed antibacterial activity against antibiotic's resistant bacteria (Bacillus cereus: β-lactamines and sulfamides resistant, Streptococcus faecalis: penicillin, tetracycline and cotrimoxazole resistant, and Staphylococcus aureus Mu 50: vancomycine resistant). The most active Streptomyces strain produces one type of polar bioactive molecules that resists to temperature variation and light exposition. Its activity appears in the first culture day and reaches its maximal value in the fourth day. The second strain presents themoresistant activity that reaches its maximal value in the first culture day. It produces two types of bioactive molecules, one is polar and the second is non polar (according to thin layer chromatography technique results).

Une souche d’actinomycetes isolee d’un echantillon de sol aride de Biskra, caracterisee comme appartenant a la serie rouge du genre Streptomyces, active contre trois bacteries a coloration de Gram positive (Staphylococcus aureus, Bacillus cereus et Streptococcus feacalis) et deux bacteries a coloration de Gram negative (Eschericha coli et Pseudomonas aeruginosa) a fait l’objet de cette etude. L’etude cinetique de la croissance et de la production d’antibacteriens a montre que l’activite antibacterienne est maximale au neuvieme jour de fermentation. Les molecules bioactives du surnageant de culture sont extraites par trois solvants de differentes polarites. Les plus grandes zones de lyse ont ete observees avec l’extrait d’acetate d’ethyle. Les substances antibacteriennes, extraites du mycelium, resistent a differents pH (de 2 a 8), gardent leur stabilite apres 30 min de chauffage a 100°C et meme apres congelation a –20°C. La chromatographie sur papier, de l’extrait du mycelium, selon la technique de Betina revele la presence de deux composes bioactifs differents

Sur un lot de cinquante-cinq souches d’actinomycètes isolées à partir d’échantillons de sol aride prélevés dans la région de Biskra, dix souches à structure filamenteuse ont été purifiées.

Fifty-five colonies are preleved following the catacteriticalaspect of Actinomycetales, from isolation mediums ensemenced by soil samples collected from desert region of Biskra. Ten strains were purified on selective medium with antifungal and anti negative Gram antibiotics. These strains produce bioactive substances against positive Gram and / or negative Gram bacteria. The strain A1with important spectrum of activity was identified with the cultural, morphological, physiological and biochemical characterisation as a member of Streptomycesgenera. It was considering belonging near to Streptomyces antibioticusand Streptomyces rochei.

Twenty-five strains of actinomycetes were isolated from samples of water, soil and tree barks collected at two sites located in the north-east of Algeria. Antimicrobial activity was tested using the agar cylinder method against three Gram-positive bacteria, three Gram-negative bacteria, three yeasts and three filamentous fungi. Among the 25 isolates 14 (56%) strains showed an activity against at least one of the test-bacteria studied and two (8%) showed antifungal activity. Ninety-three percent of the active strains were identified by the universal PCR as belonging to the Streptomyces genus and 7% to the Actinomadura genus. (c) 2005 Elsevier SAS. All rights reserved.

Dans le cadre de la recherche de nouveaux antibiotiques élaborés par des actinomycètes originaires des milieux extrêmes, l’activité antibactérienne d’une souche d’actinomycète isolée d’eau de Sebkha de Ain Mlila a été étudiée. Ses caractères morphologiques et macromorphologiques sur milieu ISP2 + 0,5 % NaCl permettent de la rapprocher de l’un des genres, Kitasatosporia, Saccharopolyspora ou. Les molécules bioactives produites par cette souche et excrétées dans le milieu de fermentation sont extraites par trois solvants de polarité différente, celles du mycélium sont retrouvées dans l’extrait méthanolique. L’étude cinétique de la croissance et de la production de substances inhibitrices, réalisée sur milieu ISP2 + 0,5 % NaCl (220 tr/ mn, 28°C), a révélé que l’activité antibactérienne de la souche A4 est maximale au quatrième jour dans le mycélium et au cinquième jour dans l’extrait butanolique du surnageant.

L'evolution constante de la resistance bacterienne aux antibiotiques et l'emergence de nouvelles maladies infectieuses justifient l'urgence de disposer de nouvelles molecules antimicrobiennes. Des echantillons d’eau et de sol environnant de Sebkha ont ete explores dans le cadre de la recherche de souches actinomycetales productrices, eventuellement, de nouveaux antibiotiques. Sur les quatre milieux d’isolement utilises, quarante deux types de colonies bacteriennes se rapprochant par leur aspect macroscopique aux actinomycetes ont ete prelevees. L’observation microscopique a l’etat frais et apres coloration de Gram a revele que parmi les quarante deux colonies trente-neuf sont a coloration de Gram positive dont cinq souches seulement presentent un aspect filamenteux, quelque fois fragmente ; ce qui les rapprochent d'une maniere certaine aux actinomycetes filamenteux. Apres purification, l'activite antibacterienne des cinq souches actinomycetales a ete mise en evidence sur deux milieux de composition differente et par deux techniques de diffusion sur gelose : technique de la double couche et technique des cylindres d'agar. Toutes les souches ont presente une activite inhibitrice a l'egard des souches bacteriennes-tests de collection a coloration de Gram positive et/ou a coloration de Gram negative et ceci quelle que soit la technique utilisee. Trois souches d'entre elles ont montre une activite vis a vis d’Aspergillus niger, d’Aspergillus oryzae et deCandida albicans. L’analyse statistique a revelee que la mise en evidence de l’activite antibacterienne et de l’activite antifongique dependent, a la fois, des souches actinomycetales etudiees, dela composition des milieux de culture et des microorganismes-tests utilises.

As part of a research program whose aim is to identify new antifungal metabolites from rare actinomycetes, three Saharan soils from south east Algeria were analyzed. Twenty-seven (27) strains of actinomycetes were isolated and tested for their antifungal activity. The soil from the region of Biskra gave the highest number of actinomycetes, i.e. 52% versus 18% and 30% for the soils from El-Oued and Ourgla, respectively. The results of this study showed the GLM medium to be the most favorable for the isolation of actinomycetes from these ecosystems, on its own providing 17 strains out of the total number of actinomycetes isolated. Two strains presented very important antifungal activity against most of the filamentous fungi and test yeasts used. Molecular identification by polymerase chain reaction using universal 16S rDNA primers allowed the two active strains to be classified in the genus Streptomyces. (c) 2005 Elsevier SAS. All rights reserved.