Impact Of Carbon Sources Research Articles

Impact of Carbon Source on Bacterial Cellulose Network Architecture and Prolonged Lidocaine Release.

The biosynthesis of bacterial cellulose (BC) is significantly influenced by the type of carbon source available in the growth medium, which in turn dictates the material's final properties. This study systematically investigates the effects of five carbon sources-raffinose (C18H32O16), sucrose (C12H22O11), glucose (C6H12O6), arabinose (C5H10O5), and glycerol (C3H8O3)-on BC production by Komagataeibacter hansenii. The varying molecular weights and structural characteristics of these carbon sources provide a framework for examining their influence on BC yield, fiber morphology, and network properties. BC production was monitored through daily measurements of optical density and pH levels in the fermentation media from day 1 to day 14, providing valuable insights into bacterial growth kinetics and cellulose synthesis rates. Scanning electron microscopy (SEM) was used to elucidate fibril diameter and pore size distribution. Wide-angle X-ray scattering (WAXS) provided a detailed assessment of crystallinity. Selected BC pellicles were further processed via freeze-drying to produce a foam-like material that maximally preserves the natural three-dimensional structure of BC, facilitating the incorporation and release of lidocaine hydrochloride (5%), a widely used local anesthetic. The lidocaine-loaded BC foams exhibited a sustained and controlled release profile over 14 days in simulated body fluid, highlighting the importance of the role of carbon source selection in shaping the BC network architecture and its impact on drug release profile. These results highlight the versatility and sustainability of BC as a platform for wound healing and drug delivery applications. The tunable properties of BC networks provide opportunities for optimizing therapeutic delivery and improving wound care outcomes, positioning BC as an effective material for enhanced wound management strategies.

Impact of carbon sources in airport de-icing compounds on the growth of Sphaerotilus natans.

Airport de-icing has been linked with the growth of undesirable river biofilms (URBs, formerly "sewage fungus"), a manifestation of organic pollution causing long-term ecological damage to watercourses. URBs are a polymicrobial community, with one key taxon standing out in literature: Sphaerotilus natans, a filamentous bacterium also found in sewage treatment and activated sludges. An industry often implicated in causing URBs is airport de-icing, with large biofilms often developing downstream of airport discharges in winter months. However, it is not yet clear which de-icers may cause URBs and how they influence growth. Therefore, specific objectives were to (i) determine which freeze-point depressants (FPDs) can be utilized by S. natans; (ii) examine differences in the growth kinetics between FPDs; and (iii) compare pure-FPDs to commercial airport de-icers (CADs) as carbon sources, to determine impacts of additives. This study employed a turbidimetric micro-batch culture design to conduct microbial growth experiments, using S. natans and a minimal medium supplemented with airport de-icer as the carbon source. Equimolar carbon concentrations were used to compare the effects of common FPDs and CADs - each containing a specific FPD. Growth was assessed via optical density (OD600) measurements, from which time-to-detection, maximum rate of change, and maximum optical density were derived and kinetics inferred. S. natans was found to grow effectively on all FPDs tested, although the microbial yield was heavily dependent on the carbon concentration for all FPDs and CADs. Sodium acetate generated the quickest growth, with the lowest TTD (lag-time) for all but the lowest concentrations tested. Propylene glycol produced the greatest maxOD (total growth), whereas ethylene glycol had a higher limiting concentration for maxROC (growth rate). The mixture of compounds and additives in commercial products did not significantly impact the growth of S. natans. This research provides evidence from controlled laboratory experiments that airport de-icers support the growth of S. natans. The differences in growth kinetics observed for the FPDs and CADs could inform improved mitigation or treatment to reduce the incidence and ecological impacts of URBs.

The impact of carbon source on cell growth and the production of bioactive compounds in cell suspensions of Hancornia speciosa Gomes

Belonging to the Brazilian flora, the species Hancornia speciosa (Gomes), known as mangabeira, has bioactive compounds of interest, such as flavonoids, xanthones, and proanthocyanidins. The objective of this study was to determine how the supplementation of sugars in culture medium affects the osmotic potential of the medium, as well as its influence on cell growth and on the concentration of phenolic compounds. For this purpose, after 90 days of subculture, 20 mL aliquots of the cultures were added to flasks containing 20 mL of medium with different sugars (glucose, fructose, sucrose, mannitol, and sorbitol) under a 16-h photoperiod with a spectral range between 400 and 700 nm of photosynthetically active radiation (45–55 μmol m−2 s−1) in a shaker at 110 rpm. After 30 days, the pH, electrical conductivity, osmotic potential, biomass accumulation, and concentrations of phenolic compounds were evaluated. Regardless of their concentration in the medium, the sugars sorbitol and mannitol provided more unfavorable conditions for water absorption at the cellular level, reducing the water potential of the medium. Sucrose favored greater water absorption and biomass accumulation. Among the various sugar concentrations, 3% (30 g/L) sucrose or glucose improved the accumulation of fresh and dry cell weight and the production of polyphenols such as chlorogenic acid, epicatechin, rosmarinic acid, hesperidin, rutin, and quercetin. In addition, they resulted in a higher osmotic potential of the medium and larger cells than other carbon sources. Despite the differences in cell size, no culture conditions compromised cell survival.

Fructose based hyper production of poly-3-hydroxybutyrate from Halomonas sp. YLGW01 and impact of carbon sources on bacteria morphologies

Polyhydroxyalkanoates (PHA), such as poly (3-hydroxybutyrate) (PHB), have emerged as potential alternatives to petroleum-based plastics and can be produced through the appropriate selection of marine bacteria that are already adapted to high salt and low temperature conditions without the requirement of antibiotic treatment. The present study, thus, aimed to screen and characterize thirteen PHA-producing microbial strains isolated from the Gwangalli beach in Busan, South Korea. Among them, Halomonas sp. YLGW01 produced the highest amount of PHB (94.6 ± 1.8% (w/w)) using fructose. Interestingly Halomonas sp. YLGW01 showed increase in cell size (8.39 ± 3.63 μm) with fructose as carbon source as compared to glucose (2.34 ± 0.44 μm). Fructose syrup was investigated as carbon source under unsterilized conditions and 95.26 ± 1.78% of PHB was produced. Overall, this strain showed the highest PHB contents in halotolerant bacteria.

Impact of carbon source and COD/N on the concurrent operation of partial denitrification and anammox.

In this study, concurrent operation of anammox and partial denitrification within a nonacclimated mixed culture system was proposed. The impact of carbon sources (acetate, glycerol, methanol, and ethanol) and COD/NO3- -N ratio on partial denitrification selection under both short- and long-term operations was investigated. Results from short-term testing showed that all carbon sources supported partial denitrification. However, acetate and glycerol were preferred due to their display of efficient partial denitrification selection, which may be related to their different electron transport pathways in comparison with methanol. Long-term operation confirmed results of batch tests by showing the contribution of partial denitrification to nitrate removal above 90% after acclimation in both acetate and glycerol reactors. In contrast, methanol showed challenges of maintaining efficient partial denitrification. COD/NO3- -N ratio mainly controlled the rate of nitrate reduction and not directly partial denitrification selection; thus, it should be used to balance between denitrification rate and anammox rate. PRACTITIONER POINTS: The authors aimed to investigate the impact of carbon sources and COD/NO3-N ratio on partial denitrification selection. All the carbon sources supported partial denitrification as long as the nitrite sink was available. 90% partial denitrification could be achieved with both acetate and glycerol in long-term operations. COD/NO3-N ratio did not directly control partial denitrification but can be used to balance between denitrification rate and anammox rate.

The Impact of Carbon Source as Electron Donor on Composition and Concentration of Dissolved Organic Nitrogen in Biosorption-Activated Media for Stormwater and Groundwater Co-Treatment.

Eutrophication has been a long-term issue in aquatic environments, where dissolved organic nitrogen (DON) recalcitrance is important. Bioavailable nitrogen qualification and quantification for effluents from stormwater and wastewater are always a challenge. The information in this study deepens the understanding of the interactions between carbon addition and DON decomposition through linear-ditch best management practices for stormwater and groundwater cotreatment. By running a laboratory-scale column study for nitrogen removal using green sorption media, the variation in composition and concentration of DON can be further linked to the population dynamics of microbial species that dominate the nitrification and denitrification processes. With the varying levels of influent total nitrogen concentration, the efficacy of nitrogen removal via biosorption activated media may be realized at the molecular level with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry.

Impact of carbon source on β-cryptoxanthin production by Kocuria marina DAGII: a classical approach

Kocuria marina DAGII, a potent β-cryptoxanthin (β-CRX) producer, was previously isolated in our laboratory during routine screening of pigment producing bacteria. In this study, a classical approach of one factor at a time was applied for obtaining the maximum β-CRX yield by Kocuria marina DAGII. Growth kinetics and reducing sugar estimation were also done. The β-CRX production medium consisted of Yeast Extract (10 g/L), Bacteriological Peptone (5 g/L), NaCl (4 g/L), Glucose (0-20 g/L) and Maltose (0-20 g/L) at pH 7.9. Experiments were conducted in batch mode with 1% inoculum at 25˚C and 150 rpm for 5 days. The optimal glucose concentration was quantified by varying its concentration from 0 to 20 g/L in absence of maltose. Gradual increase in β-CRX yield was observed up to 7.5 g/L (3.6 mg/L). Beyond this concentration, β-CRX yield was almost constant. Simultaneously, optimal maltose concentration was determined by varying the concentration in range of 0-20 g/L in absence of glucose. Highest β-CRX production (3.25 mg/L) was observed at 10 g/L. Concentrations higher than 10 g/L were inhibitory, suggesting substrate inhibition of β-CRX by maltose. Validation experiment was conducted with Glucose and Maltose fixed at 7.5 g/L and 10 g/L, respectively. Significant increase in β-CRX yield (4.49 mg/L) was observed at 56 h of incubation with 60% utilization of reducing sugar. The bacterium exhibited regular growth pattern in all the experimental set ups. Monod’s model described the bacterial growth with maximum specific growth rate (μmax) of 0.2500 h-1 and 0.2024 h-1 for glucose and maltose, respectively. This suggests that bacterial growth is more influenced by glucose than maltose. However, for maximal β-CRX production, both the carbon substrates are essential.

The Impact of Carbon Source, Explants and Growth Regulators on Callogenesis and Organogenesis of <i>Artemisia annua</i>

The Impact of Carbon Source, Explants and Growth Regulators on Callogenesis and Organogenesis of <i>Artemisia annua</i>

Impact of carbon sources on nitrous oxide emission and microbial community structure in an anoxic/oxic activated sludge system

The carbon source used for denitrification is a key factor in the reduction of nitrous oxide (N2O) produced from wastewater treatment plants because it affects denitrification activity. In this study, two laboratory-scale Modified Ludzak Ettinger (MLE) processes were operated with methanol and sodium acetate as the sole carbon sources. Removal efficiency of soluble nitrogen was not affected by carbon source, but the N2O emission rate from the acetate-fed MLE process (1.6 ± 0.6 μg N–N2O/min) was lower than that from the methanol-fed process (3.0 ± 0.7 μg N–N2O/min). This is supported by the batch experiment data showing the acetate-fed biomass had a higher N2O reduction rate of 10.3 mg/gVSS/h than that of the methanol-fed biomass (3.3 mg/gVSS/h). In the methanol-fed process, 34.9 % of the total bacteria was the genus Methylotenera, which is reportedly incapable of N2O reduction. The acetate-fed process enriched the genera Dechloromonas and Rubrivivax, potential N2O reducers, accounting for 12.2 and 15.9 % of the total bacteria, respectively. The results indicated that acetate is a suitable replacement for methanol for wastewater treatment plants interested in mitigating N2O emission from the MLE process.

Potential of Bacillus cereus for bioremediation of pulp and paper industrial waste

Biotechnological processes have the potential to reduce environmental pollution through their application in processes aimed at resolving waste dumping problems. In this study, Bacillus cereus was assessed for its efficiency to decolorize pulp and paper industrial effluents. The impact of carbon source, nitrogen source, temperature, initial pH and incubation period on color reduction was also studied. The optimum pH and temperature were found to be 6.5 and 45 °C, respectively. B. cereus was efficient at decolorizing the effluents in the presence of glucose, xylose and starch (84, 45.5 and 66 %, respectively), but maximum color reduction (90.6 %) was obtained with 0.5 % sucrose as the carbon source in the presence of 1 % ammonium sulphate. The substantially high load of chemical oxygen demand and biological oxygen demand was decreased by about 61 and 66 %, respectively, by B. cereus. The molecular size distribution studies of control and bacterial-treated effluent samples revealed the degradation of high and medium molecular mass compounds. The results demonstrate the high potential of B. cereus as a significant candidate for color removal from pulp and paper mill effluents.

Impact of carbon source and variable nitrogen conditions on bacterial biosynthesis of polyhydroxyalkanoates: Evidence of an atypical metabolism in Bacillus megaterium DSM 509

Twenty bacterial strains were examined on their ability to produce polyhydroxyalkanoates (PHA) from different carbon sources under rich and depleted nitrogen conditions. Preliminary experiments with glucose as sole carbon source allowed to select PHA producing bacteria using FTIR spectroscopy. They were further tested with eight additional carbon substrates including organic, fatty acids or sugars. PHA content and monomer composition of four chosen strains (Pseudomonas putida mt-2, Bacillus megaterium DSM 90 and DSM 509, Corynebacterium glutamicum DSM 20137) were assessed by gas chromatography techniques for two cultural conditions: during growth phase on a mineral medium (MM) and after transfer of cells on a fresh MM without nitrogen (MM-N). For several carbon substrates, substantial amounts of PHA (up to 53% of the cell dry weight: CDW) were already obtained in MM for C.glutamicum DSM 20137 and the two B.megaterium strains; after transfer in MM-N, PHA contents remained constant except for B.megaterium DSM 509 where PHA production increased whatever the carbon source. P.putida mt-2 synthesized PHA under deprived nitrogen conditions. Highest PHA accumulation reached 48 and 77% of CDW with octanoic acid as substrate in B.megaterium DSM 90 and P.putida mt-2, respectively. Surprisingly, an atypical metabolic shift was observed for B.megaterium DSM 509 cultivated with nearly all unrelated carbon sources: whereas short chain length PHA (scl-PHA) were synthesized in MM, medium chain length PHA (mcl-PHA) were produced after transfer of cells into MM-N supplemented with the same substrate.

Impact of carbon source on nitrous oxide emission from anoxic/oxic biological nitrogen removal process and identification of its emission sources

Wastewater treatment is an important source of nitrous oxide (N(2)O), which is a strong greenhouse gas and dominate ozone-depleting substance. The purpose of this study was to evaluate the effect of carbon source on N(2)O emission from anoxic/oxic biological nitrogen removal process. The mechanisms of N(2)O emission were also studied. Long-term experiments were operated to evaluate the effect of three different carbon sources (i.e., glucose, sodium acetate, and soluble starch) on N(2)O emission characteristics. And batch experiments, in the presence or absence of specific inhibitors, were carried out to identify the sources of N(2)O emission. The ammonia-oxidizing bacteria (AOB) and denitrifiers community compositions under different circumstances were also analyzed based on which the underlying mechanisms of N(2)O emission were elucidated. The conversion ratios of N(2)O in reactors with glucose, sodium acetate, and soluble starch were 5.3 %, 8.8 %, and 2.8 %, respectively. The primary process responsible for N(2)O emission was nitrifier denitrification by Nitrosomonas-like AOB, while denitrification by heterotrophic denitrifiers acted as the sink. Reactor with sodium acetate showed the highest N(2)O emission, together with the highest nitrogen and phosphate removal ratios. Carbon source has a significant impact on N(2)O emission quantity and relatively minor effect on its production mechanism.

Characterization of the dissolved organic matter in sewage effluent of sequence batch reactor: the impact of carbon source

Dissolved organic matter (DOM) transformation in sequence batch reactor (SBR) fed with carbon sources of different biodegradability was investigated. During the biologic degradation process, the low molecular weight (MW) fraction ( 1 kDa as well as the hydrophobic fraction in DOM gradually increased with the carbon sources changing from sodium acetate to glucose and starch. The DOC fractionation and the EEM all demonstrated that EfOM from the effluent of the SBR fed with starch contained more fulvic acid-like substances comparing with the SBR fed with sodium acetate and glucose.

CARS microscopy of lipid stores in yeast: the impact of nutritional state and genetic background

AbstractWe have developed a protocol for sub‐micrometer resolved and chemically specific imaging of lipid storage in vivo employing coherent anti‐Stokes Raman scattering (CARS) microscopy of one of the most important model organisms Saccharomyces cerevisiae—the yeast cell. By probing the carbon–hydrogen vibration using the nonlinear process of CARS, lipid droplets in the yeast cells clearly appear, as confirmed by comparative studies on relevant labeled organelles using two‐photon fluorescence microscopy. From the images, unique quantitative data can be deduced with high three‐dimensional resolution, such as the volume, shape, number, and intracellular location of the neutral lipid stores. We exemplify the strength and usability of the method for two cases: the impact on lipid storage of the nutritional condition (starvation and type of carbon source available) as well as of genetic modification of two fundamental metabolic regulation pathways involving carbohydrate and lipid storage (BCY1 and DGA1, LRO1, ARE1/2 deletions), respectively. While the impact of carbon source on the total cellular lipid volume was minimal, long‐term starvation induces a significant accumulation of lipid droplets. We also confirm that the lipid‐storage‐deficient mutant is indeed unable to synthesize lipid droplets, and that the inability of the bcy1‐mutant to store carbohydrates is compensated by a two‐fold increase in stored neutral lipids. We note that there is a significant cell‐to‐cell variability in neutral lipid storage in general, i.e. that there is a correspondence to the noise found for gene expression also in lipidomics. Copyright © 2009 John Wiley & Sons, Ltd.

The effect of carbon source on the biological reduction of ionic mercury

Mercury (Hg) is the most highly toxic heavy metal, and must be removed from waterways to very low levels. Biologically mediated mercury removal is an emerging technology that has the potential to be robust, efficient and cost-effective. In this study, the impact of carbon source on the behaviour and microbial community composition of mixed microbial cultures was evaluated, and their performance was compared with a pure culture of Pseudomonas putida spi3. Glucose and acetate, two carbon sources that are commonly present in wastewaters, were chosen for this study. Distinct microbial populations were enriched with each carbon source. Glucose led to a more suitable microbial culture for Hg 2+ bioreduction that was able to reduce Hg 2+ at faster rates when compared to acetate. Furthermore, acetate consistently led to poorer process performance, irrespective of the microbial culture, possibly due to the formation of mercuric acetate complexes. It is proposed that glucose can be a more beneficial carbon source than acetate for the successful operation of Hg bioremediation systems.

Impact of carbon sources on growth and oxalate synthesis by the phytopathogenic fungus Sclerotinia sclerotiorum

The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic potential, were dissimilar when the organism was grown in the presence of different carbon sources. The highest oxalate-to-biomass ratios were observed with pyruvate, formate, malate, acetate, and succinate. Time-course studies with acetate-supplemented cultures revealed that acetate and glucose consumption by S. sclerotiorum D-E7 coincided with oxalogenesis and culture acidification. By day 5 of incubation, oxalogenesis was halted when cultures reached a pH of 3 and were devoid of acetate. In succinate-supplemented cultures, oxalogenesis essentially paralleled glucose and succinate utilization over the 9-day incubation period; during this time period, culture pH declined but never fell below 4. Overall, these results indicate that carbon sources can regulate the accumulation of oxalate, a key pathogenicity determinant for S. sclerotiorum.

RETRACTED ARTICLE: Evaluation of carbon sources as positive selection agents for chrysanthemum (Dendranthema × grandiflorum) transformation

Fourteen different carbon sources were evaluated using thin cell layers to determine their suitability as positive selection agents for chrysanthemum (Dendranthema × grandiflorum) transformation. The choice of carbon source is an indispensable factor in the success of organogenic (callogenic, caulogenic, rhizogenic, and to a lesser extent, somatic embryogenic) programmes in in vitro micropropagation of chrysanthemum. Using flow cytometry, histological analyses, and confirmation of flowering normality, the impact of carbon source on the qualitative and quantitative outcome and response of thin cell layers when these were placed onto organogenic media was assessed. Threshold survival levels (TSLs) could not be obtained for sucrose, fructose, or glucose. TSLs together with organ differentiation were, however, obtained for mannose (60–80 g/litre), xylose and lactose (40 g/litre), and cellulose (60–80 g/litre), although abnormal shoot formation was observed in the first of these. Xylose, lactose, and cellulose can consequently be considered potential carbon sources for positive selection systems in chrysanthemum genetic transformation.

Impact of carbon source and growth conditions on carnitine acetyltransferase in Saccharomyces cerevisiae

Impact of carbon source and growth conditions on carnitine acetyltransferase in Saccharomyces cerevisiae