scholarly journals Bacterial Degradation of Cyanide and Its Metal Complexes under Alkaline Conditions

2005 ◽  
Vol 71 (2) ◽  
pp. 940-947 ◽  
Author(s):  
Víctor M. Luque-Almagro ◽  
María-J. Huertas ◽  
Manuel Martínez-Luque ◽  
Conrado Moreno-Vivián ◽  
M. Dolores Roldán ◽  
...  

ABSTRACT A bacterial strain able to use cyanide as the sole nitrogen source under alkaline conditions has been isolated. The bacterium was classified as Pseudomonas pseudoalcaligenes by comparison of its 16S RNA gene sequence to those of existing strains and deposited in the Colección Española de Cultivos Tipo (Spanish Type Culture Collection) as strain CECT5344. Cyanide consumption is an assimilative process, since (i) bacterial growth was concomitant and proportional to cyanide degradation and (ii) the bacterium stoichiometrically converted cyanide into ammonium in the presence of l-methionine-d,l-sulfoximine, a glutamine synthetase inhibitor. The bacterium was able to grow in alkaline media, up to an initial pH of 11.5, and tolerated free cyanide in concentrations of up to 30 mM, which makes it a good candidate for the biological treatment of cyanide-contaminated residues. Both acetate and d,l-malate were suitable carbon sources for cyanotrophic growth, but no growth was detected in media with cyanide as the sole carbon source. In addition to cyanide, P. pseudoalcaligenes CECT5344 used other nitrogen sources, namely ammonium, nitrate, cyanate, cyanoacetamide, nitroferricyanide (nitroprusside), and a variety of cyanide-metal complexes. Cyanide and ammonium were assimilated simultaneously, whereas cyanide strongly inhibited nitrate and nitrite assimilation. Cyanase activity was induced during growth with cyanide or cyanate, but not with ammonium or nitrate as the nitrogen source. This result suggests that cyanate could be an intermediate in the cyanide degradation pathway, but alternative routes cannot be excluded.

2005 ◽  
Vol 33 (1) ◽  
pp. 168-169 ◽  
Author(s):  
V.M. Luque-Almagro ◽  
R. Blasco ◽  
M.J. Huertas ◽  
M. Martínez-Luque ◽  
C. Moreno-Vivián ◽  
...  

Pseudomonas pseudoalcaligenes CECT5344 uses cyanide, cyanate, β-cyanoalanine, and other cyanoderivatives as nitrogen sources under alkaline conditions, which prevents volatile HCN (pKa 9.2) formation. The cyanide consumed by this strain is stoichiometrically converted into ammonium. In addition, this bacterium grows with the heavy metal, cyanide-containing waste water generated by the jewellery industry, and is also a cyanide-resistant strain which induces an alternative oxidase and a siderophore-based mechanism for iron acquisition in the presence of cyanide. The detection of cyanase and β-cyanoalanine nitrilase activities in cyanide-induced cells suggests their implication in the cyanide degradation pathway.


1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.


2001 ◽  
Vol 183 (11) ◽  
pp. 3293-3302 ◽  
Author(s):  
Anna C. Schultz ◽  
Per Nygaard ◽  
Hans H. Saxild

ABSTRACT The soil bacterium Bacillus subtilis has developed a highly controlled system for the utilization of a diverse array of low-molecular-weight compounds as a nitrogen source when the preferred nitrogen sources, e.g., glutamate plus ammonia, are exhausted. We have identified such a system for the utilization of purines as nitrogen source in B. subtilis. Based on growth studies of strains with knockout mutations in genes, complemented with enzyme analysis, we could ascribe functions to 14 genes encoding enzymes or proteins of the purine degradation pathway. A functional xanthine dehydrogenase requires expression of five genes (pucA, pucB, pucC, pucD, and pucE). Uricase activity is encoded by thepucL and pucM genes, and a uric acid transport system is encoded by pucJ and pucK. Allantoinase is encoded by the pucH gene, and allantoin permease is encoded by the pucI gene. Allantoate amidohydrolase is encoded by pucF. In a pucRmutant, the level of expression was low for all genes tested, indicating that PucR is a positive regulator of puc gene expression. All 14 genes except pucI are located in a gene cluster at 284 to 285° on the chromosome and are contained in six transcription units, which are expressed when cells are grown with glutamate as the nitrogen source (limiting conditions), but not when grown on glutamate plus ammonia (excess conditions). Our data suggest that the 14 genes and the gde gene, encoding guanine deaminase, constitute a regulon controlled by the pucR gene product. Allantoic acid, allantoin, and uric acid were all found to function as effector molecules for PucR-dependent regulation ofpuc gene expression. When cells were grown in the presence of glutamate plus allantoin, a 3- to 10-fold increase in expression was seen for most of the genes. However, expression of thepucABCDE unit was decreased 16-fold, while expression ofpucR was decreased 4-fold in the presence of allantoin. We have identified genes of the purine degradation pathway in B. subtilis and showed that their expression is subject to both general nitrogen catabolite control and pathway-specific control.


1981 ◽  
Vol 27 (7) ◽  
pp. 685-691 ◽  
Author(s):  
E. A. Barnett ◽  
W. A. Ayers

Three of five isolates of Sporidesmium sclerotivorum, a mycoparasite of Sclerotinia spp., grew well on an agar medium containing mineral salts, glucose, thiamine, and glutamine or Casamino acids as the nitrogen source. The nitrogen requirement for two of the isolates was satisfied by NH4Cl, Casamino acids, or glutamine. Glutamine was the best single nitrogen source. Only one isolate, CS-1, was used in further nutritional studies. The optimum concentration of glutamine for growth was 5 g/L. Glucose, mannose, mannitol, and cellobiose were excellent carbon sources. A glucose concentration of 20 g/L was optimum. Mannitol supported greater growth than glucose with Casamino acids as the nitrogen source but glucose was the superior carbon source with glutamine as the nitrogen source. Greatest growth was achieved with a combination of these carbon and nitrogen sources. Sporidesmium sclerotivorum, isolate CS-1, required thiamine for growth and sporulation. Biotin stimulated growth. The fungus developed maximally within the range of pH 5.0–5.5 and growth was greatly reduced at a pH below 4.0 or above 6.0. Control of acidity by the periodic addition of NaOH solution permitted substantially increased growth. The optimum temperature for growth was 22.5–25.0 °C but production of macroconidia was greatest at 15–20 °C.


1993 ◽  
Vol 71 (9) ◽  
pp. 1224-1230 ◽  
Author(s):  
L. D. Abraham ◽  
A. Roth ◽  
J. N. Saddler ◽  
C. Breuil

The sap-staining ascomycete Ophiostoma piceae strain 387N used ammonium, but not nitrate, as an inorganic nitrogen source. Organic nitrogen sources assimilated included bovine serum albumin, collagen, acid-hydrolyzed casein, urea, and various amino acids. Sucrose, glucose, maltose, raffinose, and soluble starch were suitable carbon sources. The optimum temperature for growth was near 23 °C, with an upper limit at 35 °C and minimal growth at 4 °C after 3 days. An initial pH of 6.1 yielded the greatest biomass. Proteolytic activity was greatest in cultures supplemented with protein as the nitrogen source, but some activity was detected in cultures with no assimilable source of nitrogen. Proteinases were detected throughout growth in protein-supplemented liquid media, and they appeared to hydrolyze azocoll, with optimal activity at pH 8. Isoelectric focusing gels of culture filtrates, obtained after fungal growth on protein supplemented media, showed a major proteolytic band focusing at pH 5.2. Key words: staining fungi, Ophiostoma, nutrition, biomass, proteinases.


2016 ◽  
Vol 3 (1) ◽  
pp. 69-74
Author(s):  
Simeon Gavrailov ◽  
Viara Ivanova

Abstract The effects of the carbon and nitrogen substrates on the growth of Bacillus sp. SG113 strain were studied. The use of organic nitrogen sources (peptone, beef extract, yeast extract, casein) leads to rapid cellular growth and the best results for the Bacillus strain were obtained with casein hydrolysate. From the inorganic nitrogen sources studied, the (NH4) 2SO4 proved to be the best nitrogen source. Casein hydrolysate and (NH4) 2SO4 stimulated the invertase synthesis. In the presence of Jerusalem artichoke, onion and garlic extracts as carbon sources the strain synthesized from 6 to 10 times more inulinase.


2013 ◽  
Vol 648 ◽  
pp. 389-393
Author(s):  
Shang Qin Hu ◽  
Xin Yang ◽  
Wei Wei ◽  
Xia Guo

In order to clarify the initial growth of the truffle environmental conditions, the use of PDA plus rich liquid medium, shaking method, its growth temperature, pH, humidity, moisture, illumination and the several other ecological factors is tested. The results show that the optimum temperature of the growth stage is 22-24 °C,Mycelium biomass is 1.45-1.56 g•L-1 .but the latter part of truffle formation temperature can be appropriately higher, at 25-30 °C, which is consistent with the natural temperature. PH at 6.8-7.5 in conditions is comparetively suitable for truffle growth , Mycelium biomass is 1.57-1.58 g•L-1,but alsobetter in the slightiy alkaline conditions than in the acidic environment ,which is different from the other fungi.It is suitable for its growth at about 35% moisture content and humidity of 80-85% mycelium growth is 90.1% , too much water is not conducive to truffle growth and development, so the truffle needs to loose and slightly moist soil in the growth and development. Truffle needs not too much illumination a day, 2h scattering light is enough, mycelium growth is88.7%, too long ilumination , especially in direct sunlight is not conducive to truffle growth. . And citric acid and glucose as the carbon sources, urea and tartaric acid as the nitrogen sources, the amenit of truffle growth, is respectively2.92 g•L-1、2.61 g•L-1,2.35g•L-1、2.26 g•L-1. This further research on the development as well as artificial truffle cultivation provides a theoretical reference.


2005 ◽  
Vol 187 (17) ◽  
pp. 6147-6154 ◽  
Author(s):  
Katharina Veit ◽  
Claudia Ehlers ◽  
Ruth A. Schmitz

ABSTRACT The methanogenic archaeon Methanosarcina mazei strain Gö1 uses versatile carbon sources and is able to fix molecular nitrogen with methanol as carbon and energy sources. Here, we demonstrate that when growing on trimethylamine (TMA), nitrogen fixation does not occur, indicating that ammonium released during TMA degradation is sufficient to serve as a nitrogen source and represses nif gene induction. We further report on the transcriptional regulation of soluble methyltransferases, which catalyze the initial step of methylamine consumption by methanogenesis, in response to different carbon and nitrogen sources. Unexpectedly, we obtained conclusive evidence that transcription of the mtmB2C2 operon, encoding a monomethylamine (MMA) methyltransferase and its corresponding corrinoid protein, is highly increased under nitrogen limitation when methanol serves as a carbon source. In contrast, transcription of the homologous mtmB1C1 operon is not affected by the nitrogen source but appears to be increased when TMA is the sole carbon and energy source. In general, transcription of operons encoding dimethylamine (DMA) and TMA methyltransferases and methylcobalamine:coenzyme M methyltransferases is not regulated in response to the nitrogen source. However, in all cases transcription of one of the homologous operons or genes is increased by TMA or its degradation products DMA and MMA.


2015 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Armaini ◽  
Abdi Dharma ◽  
Sumaryati Syukur ◽  
Jamsari

 Optimization have been done on the media for the growth of the isolated thermophiles bacteria from hot springs Rimbo Panti, the nutrients comprising variety of carbon sources such as CMC (carboxymethyl cellulose), avicell (micro crystalline cellulose), and cellobiose, with a variety of sources organic nitrogen, peptone, extracts yeast, tryptone, and urea, as well as variations consist of inorganic nitrogen sources, KNO3, NaNO3, (NH4)2SO4, and (NH4)NO3. Determination of cellulase activity performed using DNS reagent (3,5-dinitro salicylic acid). Maximum cellulase production with high activity based on the results of this research, the best of carbon source is CMC with optimum concentration 0.125%, inorganic nitrogen source is peptone with the optimum concentration of 0.3 to 0.4% and the inorganic nitrogen source is (NH4)2SO4 with optimum concentration of 0.2 - 0.25%. Optimization of size of inoculums obtained the optimum amount of inoculums 2%. Keywords: Optimization, thermophiles bacteria, cellulose, carbon sources, nitrogen sources


2017 ◽  
Vol 22 (1) ◽  
pp. 31 ◽  
Author(s):  
Eris Septiana ◽  
Partomuan Simanjuntak

Antioxidant is an interesting topic due to their capability to inhibit free radical and prevent damage because of oxidative processes. Endophyt fungi is one of antioxidant compound resources in nature. The low yield to gain antioxidant compound from fungi challenges to look for the composition of media and optimalization of growth conditions. This research aimed to know the effect of medium condition in different carbon and nitrogen sources as well as initial pH towards antioxidant activity of endophyt fungi Bo.Ci.Cl.A3. Shaker fermentation was used on 120 rpm at room temperature for 14 days. The carbon sources were glucose, sucrose, and starch and nitrogen sources were NaNO3, NH4NO3, and yeast extract with initial pH at 5, 7, and 9. Ethyl acetate was used as extractor. The results showed that endophyt fungi can produce secondary metabolite as antioxidant at all variation of fermented media. The nitrogen source of yeast extract could increase antioxidant activity of endophyt fungi Bo.Ci.Cl.A3, while other sources such as nitrogen source, carbon sources, and different initial pH on the basal medium that were used did not give increasing antioxidant activity. The conclusion of this research was the substitution of nitrogen source with yeast extract (3 g/L) on the basal medium Czapek Dox’s Broth could increase antioxidant activity of endophyt fungi Bo.Ci.Cl.A3.


Sign in / Sign up

Export Citation Format

Share Document