Growth morphology of Streptomyces akiyoshiensis in submerged culture: influence of pH, inoculum, and nutrients

1992 ◽  
Vol 38 (2) ◽  
pp. 98-103 ◽  
Author(s):  
M. A. Glazebrook ◽  
L. C. Vining ◽  
R. L. White

Most media in which the growth of shaken submerged cultures of Streptomyces akiyoshiensis was examined did not support the formation of well-dispersed mycelial suspensions. Investigation of the culture conditions promoting dispersed growth showed the pH of the culture medium to be of critical importance; an initial value of 5.5 minimized aggregation of the mycelium while supporting adequate biomass production. In cultures started at this pH, spore inocula gave better mycelial dispersal than did vegetative inocula; with spore inocula, growth morphology was also less affected by inoculum size. The composition of the nutrient solution influenced the extent of mycelial dispersal; slow growth was often associated with clumping but no clear correlation was observed between pellet formation and the ability of carbon or nitrogen sources to support rapid growth. Increasing the phosphate concentration from 0.5 to 15 mM caused a modest decrease in mycelial aggregation. Conditions promoting a well-dispersed mycelium suitable for studying the physiological control of secondary metabolism also supported the formation of 5-hydroxy-4-oxonorvaline by S. akiyoshiensis. Key words: Streptomyces akiyoshiensis, mycelial aggregation, growth conditions.

AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Juliana Lebeau ◽  
Thomas Petit ◽  
Laurent Dufossé ◽  
Yanis Caro

AbstractFungal naphthoquinones, like red bikaverin, are of interest due to their growing applications in designing pharmaceutical products. Though considerable work has been done on the elucidation of bikaverin biosynthesis pathway in Fusarium fujikuroi, very few reports are available regarding its bioproduction in F. oxysporum. We are hereby proposing a putative metabolic pathway for bikaverin bioproduction in a wild F. oxysporum strain by cross-linking the pigment profiles we obtained under two different fermentation conditions with literature. Naphthoquinone pigments were extracted with a pressurized liquid extraction method, and characterized by HPLC–DAD and UHPLC-HRMS. The results led to the conclusions that the F. oxysporum LCP531 strain was able to produce bikaverin and its various intermediates, e.g., pre-bikaverin, oxo-pre-bikaverin, dinor-bikaverin, me-oxo-pre-bikaverin, and nor-bikaverin, in submerged cultures in various proportions. To our knowledge, this is the first report of the isolation of these five bikaverin intermediates from F. oxysporum cultures, providing us with steady clues for confirming a bikaverin metabolic pathway as well as some of its regulatory patterns in the F. oxysporum LCP531 strain, based on the previously reported model in F. fujikuroi. Interestingly, norbikaverin accumulated along with bikaverin in mycelial cells when the strain grew on simple carbon and nitrogen sources and additional cofactors. Along bikaverin production, we were able to describe the excretion of the toxin beauvericin as main extrolite exclusively in liquid medium containing complex nitrogen and carbon sources, as well as the isolation of ergosterol derivate in mycelial extracts, which have potential for pharmaceutical uses. Therefore, culture conditions were also concluded to trigger some specific biosynthetic route favoring various metabolites of interest. Such observation is of great significance for selective production of pigments and/or prevention of occurrence of others (aka mycotoxins).


2021 ◽  
Author(s):  
Taiwo Dorcas Ibukunoluwa ◽  
Ademakinwa Adedeji Nelson ◽  
Zainab Adenike Ayinla ◽  
Femi Kayode Agboola

Abstract This study was undertaken to isolate and identify a novel cellulase-producing strain from a waste site (7°28’11’’N 4°31’24’’E), optimise the growth conditions, partially purify and biochemically characterise the enzyme. The potentials of the purified cellulase to hydrolyse the lignocellulosic component of some agro-industrial wastes (e.g. orange peels etc.) was also investigated. The best cellulase-producing fungus was identified as Mucor ramanniacus and the optimum conditions for cellulase production were pH (4.5), inoculum size (12 mm), carbon and nitrogen sources were carboxymethyl cellulose and sodium nitrate respectively resulting in a specific activity of 1423 Units/mg protein. A purification fold of 1.56 and 45.37 % yield were obtained after purification. The optimum pH and temperature were at 9.0 and 40°C respectively. The kinetic parameters were 0.63 ± 0.495 mg/ml, 20.21 ± 11.28 U/ml, 1001.4s− 1 for Km and Vmax and kcat respectively. Na+, K+, Ca+, Cysteine, β-mercaptoethanol and SDS were activators while Tween 80, Triton X-100 EDTA, Hg2+ and Ba2+ inhibited the enzyme. M. ramanniacus cellulase hydrolysed all agro-industrial wastes used. The partially purified M. ramanniacus cellulase showed great potential in biodegradation of various lignocellulosic substrates and the biochemical characteristics exhibited makes it suitable in industrial applications.


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.


2021 ◽  
Vol 12 (4) ◽  
pp. 950-966
Author(s):  
Phakamani H. Tsilo ◽  
Albertus K. Basson ◽  
Zuzingcebo G. Ntombela ◽  
Tsolanku S. Maliehe ◽  
Rajasekhar V. S. R. Pullabhotla

Biolocculants are gaining attention in research due to their environmental friendliness and innocuousness to human in comparison to the conventional flocculants. The present study aimed to investigate the ability of fungi from Kombucha tea SCOBY to produce effective bioflocculant in bulk. A 16S rRNA gene sequence analysis was utilized to identify the isolate. The medium composition (carbon and nitrogen sources) and culture conditions (inoculum size, temperature, shaking speed, pH, and time) were optimized using one-factor-at-a-time method. The functional groups, morphology, and crystallinity of the bioflocculant were evaluated using Fourier transform infrared (FT-IR), scan electron microscope (SEM) and X-ray diffractometry (XRD). The fungus was found to be Pichia kudriavzevii MH545928.1. It produced a bioflocculant with flocculating activity of 99.1% under optimum conditions; 1% (v/v) inoculum size, glucose and peptone as nutrient sources, 35 °C, pH 7 and the shaking speed of 140 rpm for 60 h. A cumulus-like structure was revealed by SEM; FT-IR displayed the presence of hydroxyl, carboxyl, amine, and thiocynates. The XRD analysis demonstrated the bioflocculant to have big particles with diffraction peaks at 10° and 40° indicating its crystallinity. Based on the obtained results, P. kudriavzevii MH545928.1 has potential industrial applicability as a bioflocculant producer.


Author(s):  
Ukponobong E. Anita ◽  
Nsikak U. Stephen ◽  
Abiodun A. Onilude ◽  
Inimfon A. Ibanga

Aims: The importance of nutritional and environmental factors in the production of microbial enzymes cannot be overemphasized. Hence, endo-β-mannanase production was systematically studied in a step-wise approach of building up on the experimentally observed conditions favouring the production of this enzyme in Aspergillus flavus PT7. Place and Duration of Study: Department of Microbiology, University of Ibadan, Nigeria, between January 2018 and December 2018. Methodology: Thirty-eight (38) fungal isolates obtained were screened for mannolytic ability using standard method. The highest producer of endo-β-mannasase was subjected to various production conditions by adjusting the nutritional and environmental factors in view of optimizing the production of this enzyme in the isolate Aspergillus flavus PT7. Results: Copra meal was the highest inducer of mannanase production in the isolate at enzyme activity of 85.86±3.93 U/gds. Production increased to 94.54±0.42 when all forms of extraneous nitrogen sources were excluded from the production medium. pH 5.0, temperature 30°C, moisture content at 100% v/w and inoculum size of 8.0% v/w led to the increase in production by 44% (enzyme activity of 153.24±5.69 U/gds) in 5 days of incubation. Allowing the production set up additional two (2) days led to production increase with a recorded enzyme activity of 170.34±4.35 U/gds. Production of endo-β-mannanase in A. flavus PT7 was observed to be inductive as the presence of simple sugars like glucose, galactose, arabinose and xylose led to extended lag period in the production of the enzymes by the isolate. Conclusion: Production of endo-β-mannanase by Aspergillus flavus PT7 was successfully optimized in a step-wise and systematic experimental study of the nutritional and environmental growth conditions of the isolate.


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.


2021 ◽  
Vol 7 (1) ◽  
pp. 42
Author(s):  
Deyamira Matuz-Mares ◽  
Oscar Flores-Herrera ◽  
Guadalupe Guerra-Sánchez ◽  
Lucero Romero-Aguilar ◽  
Héctor Vázquez-Meza ◽  
...  

Respiratory supercomplexes are found in mitochondria of eukaryotic cells and some bacteria. A hypothetical role of these supercomplexes is electron channeling, which in principle should increase the respiratory chain efficiency and ATP synthesis. In addition to the four classic respiratory complexes and the ATP synthase, U. maydis mitochondria contain three type II NADH dehydrogenases (NADH for reduced nicotinamide adenine dinucleotide) and the alternative oxidase. Changes in the composition of the respiratory supercomplexes due to energy requirements have been reported in certain organisms. In this study, we addressed the organization of the mitochondrial respiratory complexes in U. maydis under diverse energy conditions. Supercomplexes were obtained by solubilization of U. maydis mitochondria with digitonin and separated by blue native polyacrylamide gel electrophoresis (BN-PAGE). The molecular mass of supercomplexes and their probable stoichiometries were 1200 kDa (I1:IV1), 1400 kDa (I1:III2), 1600 kDa (I1:III2:IV1), and 1800 kDa (I1:III2:IV2). Concerning the ATP synthase, approximately half of the protein is present as a dimer and half as a monomer. The distribution of respiratory supercomplexes was the same in all growth conditions. We did not find evidence for the association of complex II and the alternative NADH dehydrogenases with other respiratory complexes.


2012 ◽  
Vol 496 ◽  
pp. 457-460
Author(s):  
Xiang Ping Kong

The growth conditions of a Geobacillus sp. were investigated by single-factor experiments. The strain was strictly aerobic bacterium, and could grow on hydrocarbons as the sole carbon source. The optimum carbon and nitrogen sources were 3.0% sucrose and 0.20% KNO3, respectively. The range of temperature, salinity and pH for the bacterial growth was 35-70 °C, 0-10% NaCl and 5.5-9.5, and good growth was obtained at 35-65 °C, 0.5-8% NaCl and 6.0-9.0, respectively. Particularly, the optimum temperature for the bacterial growth was between 50 °C and 60 °C. The strain had wide adaptability to the extreme conditions, and may be potentially applied to microbial enhanced oil recovery and oil-waste bioremediation technology.


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.


2016 ◽  
Vol 5 (3) ◽  
pp. 27-32 ◽  
Author(s):  
Ahmed I. Khattab ◽  
Eltahir H. Babiker ◽  
Humodi A. Saeed

The objectives of this study were to isolate and identify Streptomyces from soil sediments as well as to optimize cultural growth conditions for maximum antibacterial productivity. A total of fifty soil sediments were collected from Red Sea, Sudan. The soil sediments were pretreated and cultivated on agar medium. Promising Streptomyces spp. were isolated by agar overlay method using indicator organisms. Optimization of chemical and physical culture conditions was carried out. The later was judged by assessment of antibacterial activity. Ethyl acetate was used to extract the secondary metabolite compounds. The separation of the active ingredients was performed using both thin layer chromatography (TLC) and gas chromatography-mass spectrometer (GC-MS). The results revealed nine strains of Streptomyces. Of them two (PS1 and PS28) isolates exhibited high activity against pathogenic bacteria. The optimum growth conditions were pH 7.5, temperature at 30°C, soyabean concentration 2.5 g/l, incubation period in 7 days, MgSO4.7H2O conc. 1g/l and K2HPO4 conc. 2.5g/l. TLC test showed three and two fragments from metabolites of PS1 and PS28 respectively, while the GC-MS analysis revealed eight and eleven compounds with antibacterial activity of PS1 and PS28 respectively. It is concluded that marine is promising source of secondary metabolites.Khattab et al., International Current Pharmaceutical Journal, February 2016, 5(3): 27-32


Sign in / Sign up

Export Citation Format

Share Document