scholarly journals Enzyme Bioprospection of Marine-Derived Actinobacteria from the Chilean Coast and New Insight in the Mechanism of Keratin Degradation in Streptomyces sp. G11C

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 537
Author(s):  
Valentina González ◽  
María José Vargas-Straube ◽  
Walter O. Beys-da-Silva ◽  
Lucélia Santi ◽  
Pedro Valencia ◽  
...  
Keyword(s):  
Substrate Concentration ◽  
Major Part ◽  
Extracellular Enzymes ◽  
Incubation Temperature ◽  
Inoculum Size ◽  
Marine Actinobacteria ◽  
Valuable Alternative ◽  
Streptomyces Sp ◽  
Abundance And Diversity ◽  
Promising Source

Marine actinobacteria are viewed as a promising source of enzymes with potential technological applications. They contribute to the turnover of complex biopolymers, such as pectin, lignocellulose, chitin, and keratin, being able to secrete a wide variety of extracellular enzymes. Among these, keratinases are a valuable alternative for recycling keratin-rich waste, which is generated in large quantities by the poultry industry. In this work, we explored the biocatalytic potential of 75 marine-derived actinobacterial strains, focusing mainly on the search for keratinases. A major part of the strains secreted industrially important enzymes, such as proteases, lipases, cellulases, amylases, and keratinases. Among these, we identified two streptomycete strains that presented great potential for recycling keratin wastes—Streptomyces sp. CHA1 and Streptomyces sp. G11C. Substrate concentration, incubation temperature, and, to a lesser extent, inoculum size were found to be important parameters that influenced the production of keratinolytic enzymes in both strains. In addition, proteomic analysis of culture broths from Streptomyces sp. G11C on turkey feathers showed a high abundance and diversity of peptidases, belonging mainly to the serine and metallo-superfamilies. Two proteases from families S08 and M06 were highly expressed. These results contributed to elucidate the mechanism of keratin degradation mediated by streptomycetes.

scholarly journals Pectinase production by Aspergillus niger isolated from decomposed apple skin

2013 ◽  
Vol 48 (1) ◽  
pp. 25-32 ◽  
Author(s):  
S Islam ◽  
B Feroza ◽  
AKMR Alam ◽  
S Begum
Keyword(s):  
Aspergillus Niger ◽  
Incubation Temperature ◽  
Nitrogen Sources ◽  
Inoculum Size ◽  
Point Of View ◽  
Media Composition ◽  
Maximal Level ◽  
Pectinolytic Activity ◽  
Pectinase Activity ◽  
Pectinase Production

Pectinase activity among twelve different fungal strains, Aspergillus niger IM09 was identified as a potential one to produce maximal level 831 U/g at pH 4.0. Media composition, incubation temperature, incubation time, substrate concentration, aeration, inoculum size, assay temperature and nitrogen sources were found to effect pectinase activity. Moisture content did not affect the activity significantly. Media composition was varied to optimize the enzyme production in solid state fermentation. It was observed that the highest pectinase activity of 831.0 U/g was found to produce in presence of yeast extract as a nitrogen source in combination with ammonium sulfate in assay media. Aeration showed positive significant effects on pectinase production 755 U/g at 1000 ml flasks. The highest pectinase production was found at 2 g pectin (521 U/g) used as a substrate. Pectinolytic activity was found to have undergone catabolite repression with higher pectin concentration (205 U/g at 5 g pectin). The incubation period to achieve maximum pectinase activity by the isolated strain Aspergillus niger IM09 was 3 days, which is suitable from the commercial point of view. DOI: http://dx.doi.org/10.3329/bjsir.v48i1.15410 Bangladesh J. Sci. Ind. Res. 48(1), 25-32, 2013

scholarly journals Draft Genome Sequence of Streptomyces sp. Strain IB2014011-1, Isolated from Trichoptera sp. Larvae of Lake Baikal

2017 ◽  
Vol 5 (17) ◽  
Author(s):  
Denis V. Axenov-Gribanov ◽  
Bogdan T. Tokovenko ◽  
Yuriy V. Rebets ◽  
Irina V. Voytsekhovskaya ◽  
Zhanna M. Shatilina ◽  
...  
Keyword(s):  
Lake Baikal ◽  
Genome Sequence ◽  
Environmental Conditions ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Ancient Lake ◽  
Streptomyces Sp ◽  
Promising Source ◽  
Species Biodiversity

ABSTRACT Unique ecosystems with specific environmental conditions have been proven to be a promising source for isolation of new Actinobacteria strains. Ancient Lake Baikal is one of the greatest examples of an ecosystem with high species biodiversity and endemicity caused by long-lasting isolated evolution and stable environmental conditions. Herein we report the draft genome sequence of Streptomyces sp. strain IB2014011-1, which was isolated from insect Trichoptera sp. larvae collected at the bottom of Lake Baikal.

scholarly journals Production of Itaconic Acid from Jatropha curcas Seed Cake by Aspergillus terreus

2013 ◽  
Vol 5 (1) ◽  
pp. 57-61 ◽  
Author(s):  
Amina M. AHMED EL-IMAM ◽  
Muinat O. KAZEEM ◽  
Mutiat B. ODEBISI ◽  
Mushaffa A. OKE ◽  
Azeezat O. ABIDOYE
Keyword(s):  
Itaconic Acid ◽  
Jatropha Curcas ◽  
Substrate Concentration ◽  
Aspergillus Terreus ◽  
Maximum Yield ◽  
Inoculum Size ◽  
Daily Maximum ◽  
Dilute Acid Hydrolysis ◽  
Seed Cake ◽  
Jatropha Seed

Submerged substrate fermentation of Jatropha seed cake, a by-product of oil extraction from Jatropha curcas seed was carried out using Aspergillus terreus for the production of itaconic acid. The Jatropha seed cake was initially converted into fermentable sugars by dilute acid hydrolysis using 50% sulphuric acid. The rate of hydrolysis was 1.04 gL-1. The fermentation process was carried out at room temperature, agitation of 400 rpm and three physico-chemical parameters (pH, inoculum size and substrate concentration) were varied. Itaconic acid and glucose assays were carried out by spectrophotometry and Dinitrosalicylic acid methods respectively daily. Maximum yield of itaconic acid was 48.70 gL-1 at 5 ml of inoculum size, 50 g substrate concentration and pH 1.5. The residual glucose concentration increased for the first two days of fermentation after which it began to decrease as the itaconic acid concentration increased. The least concentration of itaconic acid observed was 6.00 gL-1, obtained after 24 hours of fermentation with 4 ml inoculum size, 50 g substrate concentration and at pH 1.5. The findings of this work indicate that Jatropha curcas seed cake is a suitable substrate for itaconic acid production.

scholarly journals Endophytic Actinomycetes from Tea Plants (Camellia sinensis): Isolation, Abundance, Antimicrobial, and Plant-Growth-Promoting Activities

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Wenna Shan ◽  
Ying Zhou ◽  
Huihui Liu ◽  
Xiaomin Yu
Keyword(s):  
Plant Growth ◽  
Camellia Sinensis ◽  
Bioactive Metabolites ◽  
Endophytic Actinomycetes ◽  
16S Rna ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Abundance And Diversity ◽  
Tea Plants ◽  
Promising Source

Endophytic actinomycetes are a promising source of novel metabolites with diverse biological activities. Tea plants (Camellia sinensis) produce arsenals of phytochemicals, which are linked to a number of medicinal and nutritional properties. However, a systematic investigation into the abundance and diversity of cultivated actinomycetes residing in tea plants has not been performed. In this study, a total of 46 actinobacteria were recovered from leaf, stem, and root samples of 15 tea cultivars collected in Fujian province, China. Their abundance and diversity were shown to be influenced by both the genotypes and tissue types of tea plants. Based on 16S RNA sequence analysis, these isolates were taxonomically grouped into 11 families and 13 genera, includingStreptomyces,Actinomadura,Kribbella,Nocardia,Kytococcus,Leifsonia,Microbacterium,Micromonospora,Mobilicoccus,Mycobacterium,Nocardiopsis,Piscicoccus, andPseudonocardia. The genusStreptomyceswas most prevalent whereas rare genera,MobilicoccusandPiscicoccus, were reported for the first time to occur as plant endophytes. PCR screening of polyketide synthase genes (PKS-I and PKS-II) and nonribosomal peptide synthetase genes (NRPS), along with antimicrobial assays against a set of bacterial and fungal pathogens, showed that endophytic actinomycetes associated with tea plants have a high potential for producing antimicrobial metabolites. Furthermore, indole acetic acid (IAA) production and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activities were recorded in 93.5% and 21.7% of all isolates, respectively. Overall, these results indicate that endophytic actinomycetes from tea plants represent a valuable source of bioactive metabolites with antibacterial, antifungal, and plant-growth-promoting properties.

scholarly journals Streptomyces sp. Strain MUSC 125 from Mangrove Soil in Malaysia with Anti-MRSA, Anti-Biofilm and Antioxidant Activities

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3545
Author(s):  
Hefa Mangzira Kemung ◽  
Loh Teng-Hern Tan ◽  
Kok-Gan Chan ◽  
Hooi-Leng Ser ◽  
Jodi Woan-Fei Law ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Methanolic Extract ◽  
Antioxidant Activities ◽  
Pcr Amplification ◽  
Gene Clusters ◽  
Bacterial Strains ◽  
Phenotypic Analysis ◽  
Streptomyces Sp ◽  
Mangrove Soil ◽  
Promising Source

There is an urgent need to search for new antibiotics to counter the growing number of antibiotic-resistant bacterial strains, one of which is methicillin-resistant Staphylococcus aureus (MRSA). Herein, we report a Streptomyces sp. strain MUSC 125 from mangrove soil in Malaysia which was identified using 16S rRNA phylogenetic and phenotypic analysis. The methanolic extract of strain MUSC 125 showed anti-MRSA, anti-biofilm and antioxidant activities. Strain MUSC 125 was further screened for the presence of secondary metabolite biosynthetic genes. Our results indicated that both polyketide synthase (pks) gene clusters, pksI and pksII, were detected in strain MUSC 125 by PCR amplification. In addition, gas chromatography-mass spectroscopy (GC-MS) detected the presence of different chemicals in the methanolic extract. Based on the GC-MS analysis, eight known compounds were detected suggesting their contribution towards the anti-MRSA and anti-biofilm activities observed. Overall, the study bolsters the potential of strain MUSC 125 as a promising source of anti-MRSA and antibiofilm compounds and warrants further investigation.

scholarly journals Antifungal susceptibility testing.

1993 ◽  
Vol 6 (4) ◽  
pp. 367-381 ◽  
Author(s):  
J H Rex ◽  
M A Pfaller ◽  
M G Rinaldi ◽  
A Polak ◽  
J N Galgiani
Keyword(s):  
Susceptibility Testing ◽  
Incubation Temperature ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Inoculum Size ◽  
Antifungal Susceptibility Testing ◽  
National Committee ◽  
Candida Spp ◽  
Interlaboratory Variability ◽  
Future Work

Unlike antibacterial susceptibility testing, reliable antifungal susceptibility testing is still largely in its infancy. Many methods have been described, but they produce widely discrepant results unless such factors as pH, inoculum size, medium formulation, incubation time, and incubation temperature are carefully controlled. Even when laboratories agree upon a common method, interlaboratory agreement may be poor. As a result of numerous collaborative projects carried out both independently and under the aegis of the Subcommittee on Antifungal Susceptibility Testing of the National Committee for Clinical Laboratory Standards, the effects of varying these factors have been extensively studied and a standard method which minimizes interlaboratory variability during the testing of Candida spp. and Cryptococcus neoformans has been proposed. This review summarizes this work, reviews the strengths and weaknesses of the proposed susceptibility testing standard, and identifies directions for future work.

scholarly journals Canola Cake as a Potential Substrate for Proteolytic Enzymes Production by a Selected Strain of Aspergillus oryzae: Selection of Process Conditions and Product Characterization

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Adriana C. Freitas ◽  
Ruann J. S. Castro ◽  
Maria A. Fontenele ◽  
Antonio S. Egito ◽  
Cristiane S. Farinas ◽  
...  
Keyword(s):  
Aspergillus Oryzae ◽  
Protease Activity ◽  
Incubation Temperature ◽  
Initial Conditions ◽  
Proteolytic Enzymes ◽  
Inoculum Size ◽  
Protease Production ◽  
Process Conditions ◽  
Enzymatic Extract ◽  
Technological Advances

Oil cakes have excellent nutritional value and offer considerable potential for use in biotechnological processes that employ solid-state fermentation (SSF) for the production of high value products. This work evaluates the feasibility of using canola cake as a substrate for protease production by a selected strain of Aspergillus oryzae cultivated under SSF. The influences of the following process parameters were considered: initial substrate moisture content, incubation temperature, inoculum size, and pH of the buffer used for protease extraction and activity analysis. Maximum protease activity was obtained after cultivating Aspergillus oryzae CCBP 001 at 20°C, using an inoculum size of 107 spores/g in canola cake medium moistened with 40 mL of water to 100 g of cake. Cultivation and extraction under selected conditions increased protease activity 5.8-fold, compared to the initial conditions. Zymogram analysis of the enzymatic extract showed that the protease molecular weights varied between 31 and 200 kDa. The concentrated protease extract induced clotting of casein in 5 min. The results demonstrate the potential application of canola cake for protease production under SSF and contribute to the technological advances needed to increase the efficiency of processes designed to add value to agroindustrial wastes.

scholarly journals Biotransformation of Pharmaceuticals by Comamonas and Aeromonas Species

2021 ◽  
Author(s):  
Atika Sajid ◽  
Saira Yahya
Keyword(s):  
Incubation Temperature ◽  
Growth Conditions ◽  
Inoculum Size ◽  
Aeromonas Species ◽  
Bacterial Strains ◽  
Pharmaceutical Residues ◽  
Healthcare Settings ◽  
Increased Risk ◽  
Rdna Sequencing ◽  
Initial Ph

Abstract Background: Contamination of natural niches with pharmaceutical residues has emerged out as a serious concern. Disposal of untreated effluents from the pharmaceutical, hospital, and domestic settings has been identified as a significant source of such a massive spread of antibiotics. The unnecessary persistence of pharmaceutical residues including antibiotics has been related to the increased risk of resistance selection among pathogenic and non-pathogenic microorganisms. To date, several methods have been devised to eliminate such pollutants from wastewater, but their implication on larger scales is not feasible due to complexities and high costs of the processes, especially in developing and underdeveloped countries. This study aimed to isolate and characterize bacterial strains from domestic and pharmaceutical effluents having biotransformation potential towards most persistent antibiotics. Results: Antibiotic resistance screening and MIC determination experiments indicated highest resistivity of three bacterial isolates against two antibiotics Erythromycin and Sulfamethoxazole-trimethoprim, evincing extensive usage of these antibiotics in our healthcare settings. These isolates were identified as Comamonas jiangduensis, Aeromonas caviae and Aeromonas hydrophila by 16S rDNA sequencing. Growth conditions including incubation temperature, initial pH and inoculum size were optimized for these strains. Successful biotransformation of Erythromycin and Sulfamethoxazole-trimethoprim was achieved within 92 h under optimum growth conditions. Conclusions: Aeromonas and Comononas species were found to be potent degraders of antibiotics tested, presenting these strains as potential candidates to be utilized in the remediation processes.

scholarly journals Enhancement of Cellulose Rich Organic Matter Degradation by Inoculation with Streptomyces sp. Strains

2021 ◽  
Vol 26 (02) ◽  
pp. 257-262
Author(s):  
Simonida Djuri
Keyword(s):  
Organic Matter ◽  
Extracellular Enzymes ◽  
Biochemical Characterization ◽  
Cellulose Degradation ◽  
Organic Matter Degradation ◽  
Incubation Experiment ◽  
Cellulose Production ◽  
Streptomyces Sp ◽  
Streptomyces Spp

Microbial degradation of organic matter is a vital part of carbon cycle in nature. Actinobacteria play an important role in the decomposition of cellulose rich organic matter (CROM). Streptomyces spp. are abundant in soil, produce various secondary metabolites and secrete extracellular enzymes. The aim of this research was to isolate and select Streptomyces strains with the best cellulose degradation abilities. Out of total 32 actinobacteria isolates, four Streptomyces strains (CA1, CA10, PA2 and PA7) were subjected to morphological, physiological, biochemical characterization and molecular identification. CROM degradation potential of the strains was investigated on straw and beech briquettes as well as on legume based substrate in in vitro condition. Streptomyces strains CA1 and CA10 showed the best cellulose production and starch hydrolysis abilities, followed by strains PA2 and PA7. Strain CA1 was also positive to production of pectinase enzymes. Streptomyces zaomyceticus CA1 and S. tanashiensis CA10 were used as inoculants, which degraded the raw cellulose from 38.38 to 81.69% in the investigated substrates (straw, beech, legume), during a 30-day incubation experiment. CROM inoculation with the selected Streptomyces strains improved and accelerated its degradation in controlled conditions. © 2021 Friends Science Publishers

scholarly journals Milk-clotting proteases from Pleurotus albidus: an innovative alternative for the production of Minas frescal cheese

2021 ◽  
Vol 43 ◽  
pp. e57275
Author(s):  
Salomão Rocha Martim ◽  
Larissa Svetlana Cavalcante Silva ◽  
Mircella Marialva Alecrim ◽  
Lorisa Simas Teixeira ◽  
Maria Francisca Simas Teixeira
Keyword(s):  
Temperature Stability ◽  
Iodoacetic Acid ◽  
Inoculum Size ◽  
Cultivation Medium ◽  
Fermentation Time ◽  
Milk Clotting ◽  
Inoculum Age ◽  
Initial Ph ◽  
Promising Source ◽  
Stability Effect

Pleurotus albidus, a naturally growing species in the Amazon region, has been considered a promising source of milk-clotting proteases. The production of such enzymes using lignocellulosic residues is a sustainable alternative to replace mammalian rennet. The application of P. albidus milk-clotting proteases in cheese making has not yet been reported in the scientific literature. The aim of this study was to characterize the milk-clotting proteases of P. albidus and use these enzymes in the production of Minas frescal cheese. For the production of coagulating proteases, the mushroom was grown in açaí seeds supplemented with rice bran (10%, w/w). The parameters affecting the production of coagulant, such as inoculum size, fermentation time, initial pH of cultivation medium and age of the inoculum were evaluated. The coagulant extract obtained under optimal production conditions was evaluated for optimal pH and temperature, pH and temperature stability, effect of ions and inhibitors. Significant production of coagulating proteases was obtained under the following conditions: inoculum size (2.5%), fermentation time (10 days), initial pH of the cultivation medium (6), and inoculum age (10 days). The coagulant exhibited significant catalytic activity in pH 5.0 at 55°C, with stability at 45°C and was completely inhibited by iodoacetic acid. The milk-clotting proteases of P. albidus were efficient for making Minas frescal cheese that presented 55.0% of moisture, 20.0% of lipids and 17.20% of protein. Pleurotus albidus is a potential source of milk-clotting proteases that can be applied in dairy industry for production of fresh Minas frescal cheese.

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