Nitrogen Source For Growth Research Articles

Nicotine-degrading microorganisms and their potential applications.

Nicotine-degrading microorganisms (NDMs) are a special microbial group which can use nicotine as the sole carbon and nitrogen source for growth. Since the 1950s, the bioconversion of nicotine by microbes has received increasing attention, and several NDMs have been identified, such as Arthrobacter nicotinovorans, Microsporum gypseum, Pellicularia filamentosa JTS-208, and Pseudomonas sp. 41. In recent years, increasing numbers of NDMs have been isolated and identified from tobacco plantation soil, leaf, and tobacco waste. Meanwhile, the metabolic pathway and degradation mechanism of nicotine have been elucidated in several NDMs, such as A. nicotinovorans, Agrobacterium tumefaciens S33, Aspergillus oryzae, and Pseudomonas putida S16. Moreover, several NDMs have been used in improving the quality of cigarettes, treating tobacco waste, and producing valuable intermediates of nicotine. Here, we summarize the diversity, phylogenetic analysis, and potential applications of NDMs.

Isolation and identification of antioxidant producing marine-source actinomycetes and optimal medium conditions

Actinomycetes strain S-1 containing antioxidant components was isolated from the coast of Jeju Island in Korea and identified to the genus level using 16S ribosomal DNA sequencing and cellular fatty acids analysis as Nocardiopsis sp. (S-1). S-1 cultured supernatants showed high DPPH radical scavenging activities and hydroxyl radical scavenging abilities of up to 53%. Nutritional and culture conditions for antioxidant production were optimized. Galactose and yeast extracts were the best carbon and nitrogen sources for growth and antioxidant production. An initial medium acidity of pH 7.6, an incubation temperature of 25°C, a sodium chloride concentration of 2.5%, and an incubation time of 8 days were optimal. The DPPH scavenging activity of culture supernatants was 88% under optimum conditions. The S-1 strain can be useful for the functional fermented food and medicine industries.

Germination of Aspergillus niger conidia is triggered by nitrogen compounds related to L-amino acids.

Conidial germination is fundamentally important to the growth and dissemination of most fungi. It has been previously shown (K. Hayer, M. Stratford, and D. B. Archer, Appl. Environ. Microbiol. 79:6924-6931, 2013, http://dx.doi.org/10.1128/AEM.02061-13), using sugar analogs, that germination is a 2-stage process involving triggering of germination and then nutrient uptake for hyphal outgrowth. In the present study, we tested this 2-stage germination process using a series of nitrogen-containing compounds for the ability to trigger the breaking of dormancy of Aspergillus niger conidia and then to support the formation of hyphae by acting as nitrogen sources. Triggering and germination were also compared between A. niger and Aspergillus nidulans using 2-deoxy-D-glucose (trigger), D-galactose (nontrigger in A. niger but trigger in A. nidulans), and an N source (required in A. niger but not in A. nidulans). Although most of the nitrogen compounds studied served as nitrogen sources for growth, only some nitrogen compounds could trigger germination of A. niger conidia, and all were related to L-amino acids. Using L-amino acid analogs without either the amine or the carboxylic acid group revealed that both the amine and carboxylic acid groups were essential for an L-amino acid to serve as a trigger molecule. Generally, conidia were able to sense and recognize nitrogen compounds that fitted into a specific size range. There was no evidence of uptake of either triggering or nontriggering compounds over the first 90 min of A. niger conidial germination, suggesting that the germination trigger sensors are not located within the spore.

Draft Genome Sequence of a Novel Streptomyces griseorubens Strain, JSD-1, Active in Carbon and Nitrogen Recycling.

Streptomyces griseorubens JSD-1, isolated from compost-treated soil, is able to utilize lignocellulose and nitrate as its sole carbon and nitrogen source for growth. Here, we announce the draft genome map of this actinomycete. The genes participating in lignocellulose and nitrate metabolism were picked out and identified.

Genes of the N -Methylglutamate Pathway Are Essential for Growth of Methylobacterium extorquens DM4 with Monomethylamine

Monomethylamine (MMA, CH3NH2) can be used as a carbon and nitrogen source by many methylotrophic bacteria. Methylobacterium extorquens DM4 lacks the MMA dehydrogenase encoded by mau genes, which in M. extorquens AM1 is essential for growth on MMA. Identification and characterization of minitransposon mutants with an MMA-dependent phenotype showed that strain DM4 grows with MMA as the sole source of carbon, energy, and nitrogen by the N-methylglutamate (NMG) pathway. Independent mutations were found in a chromosomal region containing the genes gmaS, mgsABC, and mgdABCD for the three enzymes of the pathway, γ-glutamylmethylamide (GMA) synthetase, NMG synthase, and NMG dehydrogenase, respectively. Reverse transcription-PCR confirmed the operonic structure of the two divergent gene clusters mgsABC-gmaS and mgdABCD and their induction during growth with MMA. The genes mgdABCD and mgsABC were found to be essential for utilization of MMA as a carbon and nitrogen source. The gene gmaS was essential for MMA utilization as a carbon source, but residual growth of mutant DM4gmaS growing with succinate and MMA as a nitrogen source was observed. Plasmid copies of gmaS and the gmaS homolog METDI4690, which encodes a protein 39% identical to GMA synthetase, fully restored the ability of mutants DM4gmaS and DM4gmaSΔmetdi4690 to use MMA as a carbon and nitrogen source. Similarly, chemically synthesized GMA, the product of GMA synthetase, could be used as a nitrogen source for growth in the wild-type strain, as well as in DM4gmaS and DM4gmaSΔmetdi4690 mutants. The NADH:ubiquinone oxidoreductase respiratory complex component NuoG was also found to be essential for growth with MMA as a carbon source.

Comparative Studies on Simultaneous Adsorption and Biodegradation, Adsorption and Biodegradation for Treatment of Wastewater containing Cyanide and Phenol

This paper presents a comparative study of the efficiency of biodegradation, adsorption and simultaneous adsorption and biodegradation (SAB) process for the remediation of industrial wastewaters containing both cyanide and phenol. Adsorption was carried out using granular activated carbon (GAC), while biodegradation was achieved by co-fermentation with Pseudomonas putida and Azotobacter chroococcum. During co-metabolism P. putida utilized phenol as carbon source while A. chroococcum utilized cyanide as nitrogen source for growth. The biodegradation efficiency decreased with increasing concentrations of phenol and cyanide and was observed as 99.99, 92.45, 86.12, 75.21 and 60.34% for cyanide and 99.61, 85.62, 79.15, 64.21 and 56.63% for phenol respectively after 60 h of agitation when initial concentration was increased from 50–350 mg L−1. With adsorption on GAC, the removal efficiencies were found to be 85.8, 77.67, 75.51, 58.25 and 50.73% for cyanide and 73.92, 72.99, 71.23, 60.13 and 51.55% for phenol respectively after 72 h of agitation. However SAB process was found to be better than biodegradation or adsorption alone in terms of both removal efficiency and time required for remediation with removal efficiencies > 94% for initial cyanide and phenol concentrations of 50 and 100 mg L−1.

Microbial Degradation of Acetamiprid by Ochrobactrum sp. D-12 Isolated from Contaminated Soil

Neonicotinoid insecticides are one of the most important commercial insecticides used worldwide. The potential toxicity of the residues present in environment to humans has received considerable attention. In this study, a novel Ochrobactrum sp. strain D-12 capable of using acetamiprid as the sole carbon source as well as energy, nitrogen source for growth was isolated and identified from polluted agricultural soil. Strain D-12 was able to completely degrade acetamiprid with initial concentrations of 0–3000 mg·L−1 within 48 h. Haldane inhibition model was used to fit the special degradation rate at different initial concentrations, and the parameters q max, K s and K i were determined to be 0.6394 (6 h)−1, 50.96 mg·L−1 and 1879 mg·L−1, respectively. The strain was found highly effective in degrading acetamiprid over a wide range of temperatures (25–35°C) and pH (6–8). The effects of co-substrates on the degradation efficiency of acetamiprid were investigated. The results indicated that exogenously supplied glucose and ammonium chloride could slightly enhance the biodegradation efficiency, but even more addition of glucose or ammonium chloride delayed the biodegradation. In addition, one metabolic intermediate identified as N-methyl-(6-chloro-3-pyridyl)methylamine formed during the degradation of acetamiprid mediated by strain D-12 was captured by LC-MS, allowing a degradation pathway for acetamiprid to be proposed. This study suggests the bacterium could be a promising candidate for remediation of environments affected by acetamiprid.

Biodegradation of nitroglycerin and ethylene glycol dinitrate by free and immobilized mixed cultures

Aerobic biodegradation of nitroglycerin (NG) and ethylene glycol dinitrate (EGDN), both as individual substrates and in their mixture, was tested using batch or fed-batch cultivation with free suspended cells enriched from a soil sample subjected to a long-term contamination with explosives. EGDN was degraded only in the presence of glycerol as a co-substrate whereas NG could serve as a sole carbon, energy and nitrogen source for growth, its degradation being only slightly boosted by either glycerol or pyruvate. NG was not sufficient as a co-substrate for microbial growth on EGDN; furthermore, the presence of EGDN inhibited the NG degradation. The growth inhibition by both NG and EGDN was alleviated by the addition of glycerol. At an optimum nitroglycerin concentration of 30 mg/L, a maximum specific degradation rate of 60.9 ± 1.8 mg/gdw/h was observed. The biodegradation of both pollutants occurred with a release of nitrite. A method was developed for growing substantial amounts of NG-degrading biomass in the presence of glycerol for its immobilization on expanded slate in a pot-scale packed-bed reactor. Preliminary reactor tests were conducted in a continuous operation mode yielding a 70–90% NG biodegradation up to a load of 20 mg/L/h, with a removal rate up to 16 mg/L/h.

Degradation of Bacterial Quorum Sensing Signaling Molecules by the Microscopic Yeast Trichosporon loubieri Isolated from Tropical Wetland Waters

Proteobacteria produce N-acylhomoserine lactones as signaling molecules, which will bind to their cognate receptor and activate quorum sensing-mediated phenotypes in a population-dependent manner. Although quorum sensing signaling molecules can be degraded by bacteria or fungi, there is no reported work on the degradation of such molecules by basidiomycetous yeast. By using a minimal growth medium containing N-3-oxohexanoylhomoserine lactone as the sole source of carbon, a wetland water sample from Malaysia was enriched for microbial strains that can degrade N-acylhomoserine lactones, and consequently, a basidiomycetous yeast strain WW1C was isolated. Morphological phenotype and molecular analyses confirmed that WW1C was a strain of Trichosporon loubieri. We showed that WW1C degraded AHLs with N-acyl side chains ranging from 4 to 10 carbons in length, with or without oxo group substitutions at the C3 position. Re-lactonisation bioassays revealed that WW1C degraded AHLs via a lactonase activity. To the best of our knowledge, this is the first report of degradation of N-acyl-homoserine lactones and utilization of N-3-oxohexanoylhomoserine as carbon and nitrogen source for growth by basidiomycetous yeast from tropical wetland water; and the degradation of bacterial quorum sensing molecules by an eukaryotic yeast.

Aerobic biodegradation of the sulfonamide antibiotic sulfamethoxazole by activated sludge applied as co-substrate and sole carbon and nitrogen source

Potential aerobic biodegradation mechanisms of the widely used polar, low-adsorptive sulfonamide antibiotic sulfamethoxazole (SMX) were investigated in activated sludge at bench scale. The study focused on (i) SMX co-metabolism with acetate and ammonium nitrate and (ii) SMX utilization when present as the sole carbon and nitrogen source. With SMX adsorption being negligible, elimination was primarily based on biodegradation. Activated sludge was able to utilize SMX both as a carbon and/or nitrogen source. SMX biodegradation was enhanced when a readily degradable energy supply (acetate) was provided which fostered metabolic activity. Moreover, it was raised under nitrogen deficiency conditions. The mass balance for dissolved organic carbon showed an incomplete SMX mineralization with two scenarios: (i) with SMX as a co-substrate, 3-amino-5-methyl-isoxazole represented the main stable metabolite and (ii) SMX as sole carbon and nitrogen source possibly yielded hydroxyl-N-(5-methyl-1,2-oxazole-3-yl)benzene-1-sulfonamide as a further metabolite.

Characterization of lipase producing Staphylococcus aureus MTCC 10787 from soil sample at Salem, Tamil Nadu, India

BackgroundLipases are hydrolases, an important group of biotechnologically relevant enzyme, which find immense application in industries like food, diary, pharmaceutical application. Commercial lipases are mostly produced from microbes in diverse habitats such as soil contaminated with oil, dairies, industrial wastes, oil seeds, decaying foods. Extensive studies on microbes have been made for their potential production of lipases. Of these important are: Achromobacter, Alcaligenes, Arthrobacter, Bacillus, Burkholderia, Chromobacterium, Pseudomonas including yeast and few endophytic fungi. Since, bacterial lipases are extracellular, unique in nature, it is essential to study the growth by varying the temperature, pH as well varying substrates such as carbon, nitrogen, lipid, solvent. Therefore, screening for an isolate having lipolytic activity was initiated toward the discovery of novel strain. ObjectivesTo screen, isolate, identify lipase producing organism from soil sample and optimizing growth conditions for the production of lipase under controlled nutrient supplementation. MethodologyMorphological, biochemical features was studied and final confirmation was done by 16S rRNA gene sequencing and assessed for lipase production by altering the concentration of substrates. Results16S rRNA gene sequencing confirms the organism as Staphylococcus aureus with G + C content of 51%, and submitted in GenBank under the accession number HQ658162. The sequence had 96% identity to Staphylococcus simiae. Lipase production of 17.8U, 10.9U, 14.8U was observed at 48 h, pH 7.5, 45 °C respectively. S. aureus preferred short chain fatty acid like butter fat as carbon and tryptone as nitrogen source for growth. Likewise, Triton X100 with 8.78U and Hexane with 12.03U, divalent cation like calcium stimulated lipase production. ConclusionMicrobial diversity is a major resource for biotechnological products and processes. Cost of lipase is a major component in operating enzyme catalyzed reaction. From economic perspective, lipase production by fermentation will be an advantage for large scale application. To conclude, lipase production is effected in a growth dependant fashion.

Two-Stage Cultivation of Pseudomonas sp. F12 for the Production of Enzymes Converting dl-2-Amino-Δ2-thiazoline-4-carboxylic Acid to l-Cysteine

Pseudomonas sp. F12 isolated from soil could transform DL-2-amino-Δ(2)-thiazoline-4-carboxylic acid (DL-ATC) to L-cysteine. It could grow in minimal medium containing DL-ATC as the sole carbon and nitrogen source, and the apparent activity of L-cysteine synthesis (CS) achieved 122 U/mL in a 5-L bioreactor. Pseudomonas sp. F12 could utilize glucose as carbon source and ammonia as nitrogen source for growth, but no CS activity was formed. To reduce the cost of DL-ATC, the cultivation process was divided into a growth stage on glucose and ammonia and a production stage induced by DL-ATC. The excessive glucose led to the production of byproduct(s) which seriously inhibited cell growth and CS production. Ammonium was accumulated when DL-ATC was consumed, and ammonium did not inhibit CS activity formation until 60 mM. Based on the above features, fed-batch cultivation of the growth stage was developed by supplying glucose restrictively. The volumetric CS activity was enhanced more than two times that obtained under the initial conditions.

Role of the denitrifying Haloarchaea in the treatment of nitrite-brines.

Haloferax mediterranei is a denitrifying halophilic archaeon able to reduce nitrate and nitrite under oxic and anoxic conditions. In the presence of oxygen, nitrate and nitrite are used as nitrogen sources for growth. Under oxygen scarcity, this haloarchaeon uses both ions as electron acceptors via a denitrification pathway. In the present work, the maximal nitrite concentration tolerated by this organism was determined by studying the growth of H. mediterranei in minimal medium containing 30, 40 and 50 mM nitrite as sole nitrogen source and under initial oxic conditions at 42 degrees C. The results showed the ability of H. mediterranei to withstand nitrite concentrations up to 50 mM. At the beginning of the incubation, nitrate was detected in the medium, probably due to the spontaneous oxidation of nitrite under the initial oxic conditions. The complete removal of nitrite and nitrate was accomplished in most of the tested conditions, except in culture medium containing 50 mM nitrite, suggesting that this concentration compromised the denitrification capacity of the cells. Nitrite and nitrate reductases activities were analyzed at different growth stages of H. mediterranei. In all cases, the activities of the respiratory enzymes were higher than their assimilative counterparts; this was especially the case for NirK. The denitrifying and possibly detoxifying role of this enzyme might explain the high nitrite tolerance of H. mediterranei. This archaeon was also able to remove 60% of the nitrate and 75% of the nitrite initially present in brine samples collected from a wastewater treatment facility. These results suggest that H. mediterranei, and probably other halophilic denitrifying Archaea, are suitable candidates for the bioremediation of brines with high nitrite and nitrate concentrations.

Degradation Characteristics of Pyridine and Phenolby Rhodococcus sp. Chr-9

The degradation characteristics of pyridine and phenol by Rhodococcus sp.Chr-9 were studied.The results showed that strain Chr-9 could completely degrade 200 mg L-1 of pyridine or phenol respectively supplemented as sole carbon source within 72 hours in mineral salt medium.The optimal pH and temperature for pyridine degradation by strain Chr-9 were 8.0 and 35 ℃,respectively.The degradation rate of pyridine or phenol by strain Chr-9 was negatively related with its initial concentration in mineral salt medium.Strain Chr-9 could utilize pyridine as sole carbon and nitrogen source for growth,and the supplementation of phenol could enhance the strain growth when there was no other nitrogen source except pyridine in mineral salt media.Fig 7,Ref 12

Concentration dependent glycine effect on the photosynthetic growth and bio-hydrogen production by Rhodobacter sphaeroides from mineral springs

Abstract The effect of glycine as nitrogen source on growth and H 2 production by purple non-sulfur bacterium Rhodobacter sphaeroides MDC 6521 (isolated from mineral springs in Armenia) in the presence of succinate as the carbon source was investigated. Growth rate, light absorption spectra, medium pH and oxidation-reduction potential (ORP) variation during bacterial anaerobic growth upon illumination were examined. At the presence of glycine the specific growth rate decreased significantly in comparison with control (∼25% for 5 mol m −3 or 7 mol m −3 glycine and ∼60% for 10 mol m −3 glycine). The culture initial pH 7.0 increased to ∼8.3, when 5 mol m −3 glycine was used. At the presence of 7 mol m −3 or 10 mol m −3 glycine pH was not changed much: pH raises to ∼7.6. ORP of R. sphaeroides gradually decreased to negative (−580 mV ± 20 mV) value during the growth at the presence of 5 mol m −3 glycine, indicating H 2 production. 10 mol m −3 glycine did not provide H 2 production (ORP decreased to −40 mV ± 5 mV). The results point out the concentration dependent glycine effect: 5 mol m −3 glycine can serve as nitrogen source for growth and H 2 production by R. sphaeroides ; however 10 mol m −3 glycine suppressed growth and H 2 production. This might be applied when glycine or other amino acids are used as nitrogen sources in bio-hydrogen technology with photosynthetic bacteria.

Isolation of a heavy metal-resistant 4-Chloronitrobenzene degrader Cupriavidus sp. D4 and cloning of its cnb genes

Strain D4 was isolated from the sludge of the wastewater treating system of a 4-Chloronitrobenzene (4-CNB) manufacturer. It was able to utilize 4-CNB as the sole carbon and nitrogen source for growth. Strain D4 was preliminarily identified as Cupriavidus sp. based on its physiological & biochemical characteristics and 16S rRNA gene sequence analysis. It could completely degrade 300 mg L −1 of 4-CNB within 25 h under the condition of 30 °C and pH 7.0. Strain D4 could also degrade 4-CNB in presence of heavy metals including Co 2+, Cd 2+, Pb 2+, Zn 2+, Mn 2+and so on, therefore it was an excellent candidate for the bio-treatment of 4-CNB and heavy metals co-contaminated environments. The main 4-CNB degrading related genes ( cnb A, B, Cab, D, G, Z) and arsenate resistance gene fragment of strain D4 were cloned, sequenced and analyzed, which showed high similarity with the corresponding genes of a reported 4-CNB-degrader, strain CNB-1. The cnb genes of strain D4 were located on two plasmids. This is the first report on the degradation of 4-CNB by the strain from the genus of Cupriavidus sp.

Arabidopsis and Lobelia anceps access small peptides as a nitrogen source for growth.

While importance of amino acids as a nitrogen source for plants is increasingly recognised, other organic N sources including small peptides have received less attention. We assessed the capacity of functionally different species, annual and nonmycorrhizal Arabidopsis thaliana (L.) Heynh. (Brassicaceae) and perennial Lobelia anceps L.f. (Campanulaceae), to acquire, metabolise and use small peptides as a N source independent of symbionts. Plants were grown axenically on media supplemented with small peptides (2-4 amino acids), amino acids or inorganic N. In A. thaliana, peptides of up to four amino acid residues sustained growth and supported up to 74% of the maximum biomass accumulation achieved with inorganic N. Peptides also supported growth of L. anceps, but to a lesser extent. Using metabolite analysis, a proportion of the peptides supplied in the medium were detected intact in root and shoot tissue together with their metabolic products. Nitrogen source preferences, growth responses and shoot-root biomass allocation were species-specific and suggest caution in the use of Arabidopsis as the sole plant model. In particular, glycine peptides of increasing length induced effects ranging from complete inhibition to marked stimulation of root growth. This study contributes to emerging evidence that plants can acquire and metabolise organic N beyond amino acids.

Biodegradation of carbendazim by a novel actinobacterium Rhodococcus jialingiae djl-6-2

A novel actinobacterial strain Rhodococcus jialingiae djl-6-2 capable of using carbendazim (MBC) as the sole carbon and nitrogen source for growth was used to investigate its metabolism pathway of MBC. The HPLC and MS/MS analysis showed that MBC was hydrolyzed to 2-aminobenzimidazole (2-AB) and then converted to benzimidazole or 2-hydroxybenzimidazole (2-HB). The conversion of 2-AB was inhibited by NH 4NO 3. The benzene ring of 2-HB was further opened through meta (extradiol) catechol cleavage. The inoculation of strain djl-6-2 to MBC-contaminated soil resulted in a higher degradation rate than noninoculated soil, which indicated the potential of strain djl-6-2 in bioremediation of MBC polluted soil.

Isolation and characterization of an Arthrobacter sp. strain HB-5 that transforms atrazine

A bacterial strain (HB-5) capable of utilizing atrazine as sole carbon and nitrogen source for growth was isolated from an industrial wastewater sample by enrichment culture. The isolate was identified as Arthrobacter sp. according to its phenotypic features, physiologic and biochemical characteristics, and phylogenetic analysis. The strain exhibited faster atrazine degradation rates in atrazine-containing mineral media than the well-characterized atrazine-degrading bacteria Pseudomonas sp. ADP. The broad optimum pH and temperature ranges observed for strain HB-5 indicate that it has potential for remediation of atrazine-contaminated sites. Strain HB-5 first metabolizes atrazine to yield hydroxyatrazine. Then, the bacterium metabolizes hydroxyatrazine to cyanuric acid, but could not mineralize atrazine.

L-Tryptophan catabolism by Rubrivivax benzoatilyticus JA2 occurs through indole 3-pyruvic acid pathway

Rubrivivax benzoatilyticus JA2 utilizes L: -tryptophan as the sole source of nitrogen for growth, and it has a doubling time of approximately 11 h (compared to 8 h with ammonium chloride). With cell free extracts in the presence of 2-oxoglutarate, indole-3-pyruvic acid, indole-3-acetaldehyde, indole-3-acetic acid, isatin, benzaldehyde, gallic acid and pyrogallol were identified using high performance liquid chromatography (HPLC) and liquid chromatography-mass spectroscopy (LC-MS) analysis. The conversion of L: -tryptophan into indole 3-pyruvic acid and glutamate by an enzyme aminotransferase was confirmed and the catabolism of indole-3-pyruvic acid via side chain oxidation followed by ring oxidation, gallic acid and pyrogallol were confirmed as metabolites. In addition, the proposed pathway sequential conversion of indole-3-pyruvic acid to the end product of pyrogallol was identified, including an enzymatic step that would convert isatin to benzaldehyde by an enzyme yet to be identified. At this stage of the study, the enzyme tryptophan aminotransferase in R. benzoatilyticus JA2 was demonstrated.