Algicidal activity of an actinomycete strain, Streptomyces rameus, against Microcystis aeruginosa

2016 ◽  
Vol 74 (6) ◽  
pp. 1398-1408 ◽  
Author(s):  
Kanchariya Phankhajon ◽  
Anchana Somdee ◽  
Theerasak Somdee

An actinomycete strain (KKU-A3) with algicidal activity against Microcystis aeruginosa was isolated from soil in Khon Kaen Province, Thailand. Based on its phenotypic characteristics and 16S rDNA sequence, strain KKU-A3 was identified as Streptomyces rameus. Strain KKU-A3 also exhibited algicidal activity against the cyanobacteria Synechococcus elongatus, Cylindrospermum sp. and Oscillatoria sp. A mathematical and statistical technique was used to optimize the culture conditions and maximize its anti-Microcystis activity. The single factor experiments indicated that glucose and casein were the most effective carbon and nitrogen sources, respectively, and produced the highest anti-Microcystis activity. Response surface methodology indicated that the optimum culture conditions were 19.81 g/L glucose and 2.0 g/L casein at an initial pH of 7.8 and an incubation temperature of 30 °C. The anti-Microcystis activity increased from 82% to 95% under optimum conditions. In an internal airlift loop bioreactor, the removal of M. aeruginosa KKU-13 by the bacterium was investigated in batch and continuous flow experiments. In the batch experiment, KKU-A3 displayed maximum anti-Microcystis activity of 95% at day 7, whereas in the continuous flow experiment, KKU-A3 displayed maximum anti-Microcystis activity of 95% at day 10.

2012 ◽  
Vol 9 (2) ◽  
pp. 949-961 ◽  
Author(s):  
El-Sayed E. Mostafa ◽  
Moataza M. Saad ◽  
Hassan M. Awad ◽  
Mohsen H. Selim ◽  
Helmy M. Hassan

Microbial protease represents the most important industrial enzymes, which have an active role in biotechnological processes. The objective of this study was to isolate new strain ofStreptomycesthat produce proteolytic enzymes with novel properties and the development of the low-cost medium. An alkaline protease producer strain NRC-15 was isolated from Egyptian soil sample. The cultural, morphological, physiological characters and chemotaxonomic evidence strongly indicated that the NRC-15 strain represents a novel species of the genusStreptomyces, hence the nameStrptomyces pseudogrisiolusNRC-15. The culture conditions for higher protease production by NRC-15 were optimized with respect to carbon and nitrogen sources, metal ions, pH and temperature. Maximum protease production was obtained in the medium supplemented with 1% glucose, 1% yeast extract, 6% NaCl and 100 μmol/L of Tween 20, initial pH 9.0 at 50 °C for 96 h. The current results confirm that for this strain, a great ability to produce alkaline proteases, which supports the use of applications in industry.


2019 ◽  
Vol 19 (2) ◽  
pp. 470 ◽  
Author(s):  
Siti Nor Amira Rosli ◽  
Rohaida Che Man ◽  
Nasratun Masngut

Culture conditions including initial pH media, incubation period, inoculum size, type of carbon source, type of nitrogen source and its concentration, which affect xylanase production were screened via the one-factor-at-a-time approach. The bacteria used in the production of xylanase was isolated from the landfill site at Sg. Ikan, Kuala Terengganu, Malaysia. Three characterizations of the landfill soil were investigated for their moisture content, ash content, and pH. The culture conditions range used in the experimental work were between 6–30 h for the incubation period, with initial pH between 5–9, inoculum size between 1–20% v/v, carbon, nitrogen sources, and nitrogen source concentration between 1–5% w/v. Xylanase activity was estimated using dinitrosalicylic acid (DNS) based on the release of xylose under standard assay conditions. The landfill soil was observed to have pH between pH 3.4–7.2 with a moisture content between 12.4–33.7% and ash ranged between 3.5–4.3%. Results showed that the highest xylanase activity within studied ranges was recorded at 25.91±0.0641 U/mL with 10% (v/v) inoculum size, 1% (w/v) xylose as sole carbon source, mixture of 1% (w/v) peptone and 0.25% (w/v) ammonium sulphate as nitrogen sources, which was carried out at initial pH of 8.0 for 24 h incubation.


2013 ◽  
Vol 6 ◽  
pp. 54-77
Author(s):  
Ramprasad Kuncham ◽  
K.T. Gurumurthy ◽  
N. Chandan ◽  
Aamir Javed ◽  
L.S. Ashwini ◽  
...  

Microbial conversions are gaining importance in the synthesis of important drug metabolites and their intermediates as they are good alternative to chemical synthesis since they are enantio-selective and regio-selective and even can be carried out at ambient temperature and atmospheric pressure. Till date, biocatalytic reduction of acetophenone and its derivatives has been widely reported. In the present study, we have made an attempt to carry out the microbial bioreduction of o-hydroxyacetophenone by screening some of the selected microorganisms which were obtained from culture collection centre as well as those which are isolated in our Microbiology lab. The selected microorganisms include Aspergillus ochraceous, Aspergillus flavus, Aspergillus tubingenesis, Aspergillus niger, Rhizopus stolanifer MTCC 162, Rhizopus stolanifer MTCC 2591 and Baker’s yeast.Among the seven microorganisms screened for the bioreduction of o-hydroxyacetophenone, Baker’s yeast and Aspergillus tubingenesis showed significant bioconversion where as Aspergillus ochraceous exhibited the least bioconversion.In our earlier study it was found that Aspergillus flavus has the required bioreductase enzyme, which showed the maximum conversion of p-chloroacetophenone to p-chlorophenylethanol. Hence optimization of culture conditions to get maximum enzyme expression and hence maximum conversion was thought off. The parameters considered for the study include effect of various Carbon sources, Nitrogen source, Metal ions, incubation Temperature and media pH on enzyme expression. The optimized culture a condition at which maximum bioconversion was achieved was maltose among various carbon sources. Tryptone was found to have maximum effect among the nitrogen sources. Media pH 7.6 and incubation temperature of 35 °C was found to be favourable for maximum enzyme activity. Among various divalent metal salts, addition of magnesium sulphate to the media significantly increased the enzyme activity.


2020 ◽  
Vol 8 (10) ◽  
pp. 1454
Author(s):  
Roslina Jawan ◽  
Sahar Abbasiliasi ◽  
Joo Shun Tan ◽  
Shuhaimi Mustafa ◽  
Murni Halim ◽  
...  

Antibacterial peptides or bacteriocins produced by many strains of lactic acid bacteria have been used as food preservatives for many years without any known adverse effects. Bacteriocin titres can be modified by altering the physiological and nutritional factors of the producing bacterium to improve the production in terms of yield and productivity. The effects of culture conditions (initial pH, inoculum age and inoculum size) and medium compositions (organic and inorganic nitrogen sources; carbon sources) were assessed for the production of bacteriocin-like inhibitory substances (BLIS) by Lactococcus lactis Gh1 in shake flask cultures. An inoculum of the mid-exponential phase culture at 1% (v/v) was the optimal age and size, while initial pH of culture media at alkaline and acidic state did not show a significant impact on BLIS secretion. Organic nitrogen sources were more favourable for BLIS production compared to inorganic sources. Production of BLIS by L. lactis Gh1 in soytone was 1.28-times higher as compared to that of organic nitrogen sources ((NH4)2SO4). The highest cell concentration (XmX = 0.69 ± 0.026 g·L−1) and specific growth rate (μmax = 0.14 h−1) were also observed in cultivation using soytone. By replacing carbon sources with fructose, BLIS production was increased up to 34.94% compared to BHI medium, which gave the biomass cell concentration and specific growth rate of 0.66 ± 0.002 g·L−1 and 0.11 h−1, respectively. It can be concluded that the fermentation factors have pronounced influences on the growth of L. lactis Gh1 and BLIS production. Results from this study could be used for subsequent application in process design and optimisation for improving BLIS production by L. lactis Gh1 at larger scale.


2021 ◽  
Vol 2 (6) ◽  
pp. 1-5
Author(s):  
R. E. Aso ◽  
C. Hammuel ◽  
M. Daji ◽  
J. Briska

Glyphosate-based herbicides are often used for the control of weeds grown on agricultural fields or farms. Different health problems have been reported to be associated with the use of glyphosate-based herbicides mainly due to their toxicity level. Thus, finding glyphosate utilizing microorganisms to remediate the glyphosate-based herbicides in the environment is crucial. The culture conditions for maximum utilization of glyphosate by bacterial isolates, Stenotrophomonas maltophilia, Bacillus cereus and Enterobacter aerogenes previously isolated from Ugini stream close to corn fields treated with glyphosate-based herbicide at Ofagbe, Delta State, Nigeria were optimized using mineral salt medium containing glyphosate as carbon source. The varied culture parameters assessed were temperature (30, 37 and 40 oC), pH (5, 6, 7, 8 and 9), initial glyphosate concentration (1, 3, 5, 7 and 9 g/L) and incubation time (2-14 days). Optical density (OD) at 560 nm of the culture was used to estimate cell growth or cell load of the glyphosate utilizing bacteria strains at every 2 days for 14 days. The following optimal conditions were determined: initial pH 9.0, incubation temperature 30 °C, initial concentration of glyphosate (1g/L) and incubation time of 12 days. Of the isolates on the medium containing the herbicide as sole carbon and energy source, Bacillus cereus showed the highest growth level (OD average, 0.127, pH average, 6.26. This was followed by Stenotrophomonas maltophilia (OD average = 0.114, pH average = 6.44) and Enterobacter aerogenes (OD average = 0.100, pH average, 6.56). At the increased of glyphosate in the medium there was decreased in growth of the bacteria. Bacillus cereus, Stenotrophomonas maltophilia and Enterobacter aerogenes indicated a high capacity to be able to degrade glyphosate. It is therefore concluded that the bacteria employed in this research can be recommended for bioremediation of environments contaminated with this chemical and further research should conducted to ascertain the catabolic genes present in these individual glyphosate degrading bacteria.


2012 ◽  
Vol 518-523 ◽  
pp. 453-459
Author(s):  
Li Fan Liu

Bioflocculant MBF7 was produced by a novel bioflocculant-producing microorganism HHE-P7. In order to reduce the bioflocculant producing cost, culture experiments were conducted. The effects of medium components including carbon and nitrogen sources as well as culture conditions such as pH of molasses diluents, cultivating temperature, inoculum size were investigated. The results showed when the molasses waste was diluted at COD concentration of 2000 mg/L, the optimal culture conditions for MBF7 production by HHE-P7 were inoculum size 1% (v/v), initial pH 5, cultivating temperature 25°C at the rotation speed 150 r/min. Under such conditions, MBF7 had a flocculating activity of 83% for 5 g/L kaolin clay suspension. About 3.19 g crude bioflocculant could be recovered from 1.0 L of molasses fermentation broth.


2016 ◽  
Vol 51 (2) ◽  
Author(s):  
Katarzyna Sułkowska-Ziaja ◽  
Agnieszka Szewczyk ◽  
Joanna Gdula-Argasińska ◽  
Halina Ekiert ◽  
Jerzy Jaśkiewicz ◽  
...  

The effect of carbon and nitrogen sources and initial pH and temperature of the medium on the mycelial growth of <em>Sarcodon imbricatus</em> (L.) P. Karst. in axenic liquid culture was investigated. The optimal composition of the medium was found to be: 5% fructose, 1% hydrolysate of casein, 1% yeast extract, and 0.3% KH<span><sub>2</sub></span>PO<span><sub>4</sub></span> at pH = 6 and incubation temperature of 20°C. In this condition the maximum biomass growth was observed, yielding 10.2 g L<sup>−1</sup> of dry weight after 3-week of growth. The medium regarded as optimal for growth of <em>S. imbricatus</em> mycelium was used for the production of the biomass and further chemical analysis. The quantitative and qualitative composition of phenolic acids, fatty acids, and sterols were determined using chromatographic methods. The total content of phenolic acids was 1.86 mg × 100 g<sup>−1</sup> DW, with the largest amount of protocatechuic acid (1.27 mg × 100 g<sup>−1</sup> DW). Nineteen fatty acids were estimated, including five unsaturated fatty acids, e.g., oleic and α-linolenic acid. The analysis of sterols composition revealed the presence of ergosterol and ergosterol peroxide (197.7 and 200.47 mg × 100 g<sup>−1</sup> DW, respectively). These compounds were isolated and confirmed by <sup>1</sup>H-NMR. Presented study constitutes the first report on the accumulation of substances (phenolic acids, fatty acids, and sterols) with multidirectional biological activity in the mycelial axenic culture of <em>Sarcodon imbricatus</em>.


2011 ◽  
Vol 175-176 ◽  
pp. 192-196 ◽  
Author(s):  
Li Li Feng ◽  
Jian Fei Zhang ◽  
Hui Luo ◽  
Zheng Li ◽  
Hong Jie Zhang

The paper concentrated on the optimization of the recombinant strain BL21 (DE3)-PE7-Nit. The component of culture medium and the culture conditions were optimized. The optimized medium was: yeast extract 10 g/l, L-glutamate sodium 8 g/l, MgSO4.7H2O 0.7 g/l, Isopropyl-β-D-thiogalactopyranoside 0.3 mmol/L, potassium hydrogen phosphate 0.5 g / L, phosphate Potassium 0.5 g / L and the culture condition was: initial pH 7.0, inoculum 2%. The result showed that the activity of nitrilase prepared with these conditions increased by 130.37 % through optimization.


2021 ◽  
Vol 2 (2) ◽  
pp. 234-244
Author(s):  
Thomas P. West

This review examines the production of the microbial polysaccharide gellan, synthesized by Sphingomonas elodea, on dairy and plant-based processing coproducts. Gellan is a water-soluble gum that structurally exists as a tetrasaccharide comprised of 20% glucuronic acid, 60% glucose and 20% rhamnose, for which various food, non-food and biomedical applications have been reported. A number of carbon and nitrogen sources have been tested to determine whether they can support bacterial gellan production, with several studies attempting to optimize gellan production by varying the culture conditions. The genetics of the biosynthesis of gellan has been explored in a number of investigations and specific genes have been identified that encode the enzymes responsible for the synthesis of this polysaccharide. Genetic mutants exhibiting overproduction of gellan have also been identified and characterized. Several dairy and plant-based processing coproducts have been screened to learn whether they can support the production of gellan in an attempt to lower the cost of synthesizing the microbial polysaccharide. Of the processing coproducts explored, soluble starch as a carbon source supported the highest gellan production by S. elodea grown at 30 °C. The corn processing coproducts corn steep liquor or condensed distillers solubles appear to be effective nitrogen sources for gellan production. It was concluded that further research on producing gellan using a combination of processing coproducts could be an effective solution in lowering its overall production costs.


2013 ◽  
Vol 48 (1) ◽  
pp. 25-32 ◽  
Author(s):  
S Islam ◽  
B Feroza ◽  
AKMR Alam ◽  
S Begum

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


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