Optimization of C:N ratio and minimal initial carbon source for poly(3-hydroxybutyrate) production byBacillus megaterium

In this work, the effects of different carbon:nitrogen (C:N) ratios, carbon source and initial carbon concentration, in liquid medium used for submerged fermentation, on biomass growth, succinic acid production and yield of product in substrate (YP/S) were studied. It was used three carbon sources as substrate such as glucose, xylose and sucrose and the C:N ratios studied were in the range of 2.5-35. The succinic acid production was best at a C:N ratio of 12.5:1, as much for the succinic acid production as for the yield of product in relation to the substrate (YP/S). For the biomass growth the C:N ratios of 2.5:1, 5:1 and 10:1 had only presented significant difference with regards to the too much assays. The substrate that presents the best results was the glucose with succinic acid concentrations up to 7.5 g.L-1.

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Nitrogen Removal in Oligotrophic Reservoir Water by a Mixed Aerobic Denitrifying Consortium: Influencing Factors and Immobilization Effects

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16040583 ◽

2019 ◽

Vol 16 (4) ◽

pp. 583 ◽

Cited By ~ 8

Author(s):

Hanyue Wang ◽

Tong Wang ◽

Shangye Yang ◽

Xueqing Liu ◽

Liqing Kou ◽

...

Keyword(s):

Carbon Source ◽

Simultaneous Removal ◽

Source Water ◽

Reservoir Water ◽

Carbon And Nitrogen ◽

Initial Carbon ◽

Oligotrophic Water ◽

Lower Temperature ◽

Significant Attention ◽

Immobilized Consortium

Nitrogen pollution in reservoirs has received increasing attention in recent years. Although a number of aerobic denitrifying strains have been isolated to remove nitrogen from eutrophic waters, the situation in oligotrophic water environments has not received significant attention. In this study, a mixed aerobic denitrifying consortium screened from reservoir samples was used to remove nitrogen in an oligotrophic denitrification medium and actual oligotrophic source water. The results showed that the consortium removed 75.32% of nitrate (NO3−-N) and 63.11% of the total nitrogen (TN) in oligotrophic reservoir water during a 24-h aerobic cultivation. More initial carbon source was helpful for simultaneous removal of carbon and nitrogen in the reservoir source water. NO3−-N and TN were still reduced by 60.93% and 46.56% at a lower temperature (10 °C), respectively, though the rates were reduced. Moreover, adding phosphorus promoted bacterial growth and increased TN removal efficiency by around 20%. The performance of the immobilized consortium in source water was also explored. After 6 days of immobilization, approximately 25% of TN in the source water could be removed by the carriers, and the effects could last for at least 9 cycles of reuse. These results provide a good reference for the use of aerobic denitrifiers in oligotrophic reservoirs.

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Nutrient balances for combined nitrification and denitrification in biofilters

Water Science & Technology ◽

10.2166/wst.2000.0431 ◽

2000 ◽

Vol 41 (4-5) ◽

pp. 91-95

Author(s):

B. Zwerger ◽

E. Arnold ◽

P.A. Wilderer

Keyword(s):

Carbon Source ◽

Nitrogen Balance ◽

Phosphorus Loading ◽

Phosphorus Load ◽

Treatment Efficiency ◽

Nutrient Balances ◽

Initial Carbon ◽

Set Up ◽

Efficiency Data ◽

Carbon Loading

Nutrient balances were set up for a biofiltration pilot plant operated with pre-denitrification and post-nitrification in order to gain more information about its treatment efficiency. Data collected during several weeks was used for balancing the parameters phosphorus (Ptot), carbon (COD) and nitrogen (Ntot). From the results obtained (overall deviation of 20–30%) it can be stated that 30% of the phosphorus load in the inlet was incorporated into biomass or sludge. The effluent contained between 50 and 80% of the incoming phosphorus loading. The percentage of the initial carbon loading found by sludge analysis was in the range of 60 to 80% and about 20% were measured in the effluent. Thus, only 20 to 40% were oxidized and/or utilized as carbon source for denitrification. The nitrogen balance showed similar values for incorportion as determined for phosphorus (20–40%). As not more than 20% of the incoming nitrogen load could be denitrified, 40–60% left the plant with the effluent.

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Growth and spore production of Plectosporium tabacinum

Canadian Journal of Botany ◽

10.1139/b01-110 ◽

2001 ◽

Vol 79 (11) ◽

pp. 1297-1306 ◽

Cited By ~ 4

Author(s):

Wenming Zhang ◽

Michelle Sulz ◽

Karen L Bailey

Keyword(s):

Carbon Source ◽

Carbon Concentration ◽

Mycelial Growth ◽

Liquid Culture ◽

C:N Ratio ◽

Spore Production ◽

Optimal Temperature ◽

Agar Media ◽

Galium Spurium ◽

Optimal Ph

Plectosporium tabacinum (van Beyma) M.E. Palm, W. Gams, et Nirenberg has been evaluated as a bioherbicide for the control of Galium spurium L. (false cleavers). Little is known, however, about the specific culture and sporulation requirements of this fungus on standard agar media. In addition, information on submerged liquid culture spore production is not available. This information is important for the successful culture and further development of this fungus as a biocontrol agent. This study characterized mycelial growth and sporulation of Plectosporium tabacinum on 14 different standard agar media over a range of light regimes, pH, and temperatures. Conditions required for submerged liquid culture spore production and resulting weed control efficacy were also assessed. This included the effect of liquid culture medium and pH and the effect of carbon source, nitrogen source, carbon concentration, and carbonnitrogen (C:N) ratio. Potato dextrose agar is the best agar medium for growth and spore production. On standard agar media, growth and spore production was not influenced by light regime. Medium pH did not affect mycelial growth and spore germination but the optimal pH for spore production was 7.0. The optimal temperature for the mycelial growth was between 22 and 25°C, but the optimal temperature for spore production was at either 20 or 30°C, depending upon the nutrient medium. Temperatures above 20°C were required to achieve greater than 90% spore germination. For submerged liquid culture spore production, Richard's solution (RS) is the best liquid medium for spore production. The optimal pH was 7.0 for RS but varied with culture media. Potassium nitrate and corn starch were the best nitrogen source and carbon source, respectively. A medium with a carbon concentration of 12.6 g/L and a C:N ratio of 7.5:1 is optimum for spore production and weed control efficacy.Key words: Plectosporium tabacinum, bioherbicide, mass production, fermentation, false cleavers, Galium spurium.

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Manure Source and Age Affect Survival of Zoonotic Pathogens during Aerobic Composting at Sublethal Temperatures

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-288 ◽

2015 ◽

Vol 78 (2) ◽

pp. 302-310 ◽

Cited By ~ 7

Author(s):

MARILYN C. ERICKSON ◽

CHRIS SMITH ◽

XIUPING JIANG ◽

IAN D. FLITCROFT ◽

MICHAEL P. DOYLE

Keyword(s):

C:N Ratio ◽

Animal Manure ◽

Escherichia Coli O157 ◽

Pathogen Inactivation ◽

Aerobic Composting ◽

E Coli ◽

Initial Carbon ◽

Nitrogen Amendment ◽

Chicken Litter ◽

Different Sources

Heat is the primary mechanism by which aerobic composting inactivates zoonotic bacterial pathogens residing within animal manures, but at sublethal temperatures, the time necessary to hold the compost materials to ensure pathogen inactivation is uncertain. To determine the influence of the type of nitrogen amendment on inactivation of Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7 in compost mixtures stored at sublethal temperatures, specific variables investigated in these studies included the animal source of the manure, the initial carbon/nitrogen (C:N) ratio of the compost mixture, and the age of the manure. Salmonella and L. monocytogenes were both inactivated more rapidly in chicken and swine compost mixtures stored at 20°C when formulated to an initial C:N ratio of 20:1 compared with 40:1, whereas a C:N ratio did not have an effect on inactivation of these pathogens in cow compost mixtures. Pathogen inactivation was related to the elevated pH of the samples that likely arises from ammonia produced by the indigenous microflora in the compost mixtures. Indigenous microbial activity was reduced when compost mixtures were stored at 30°C and drier conditions (<10% moisture level) were prevalent. Furthermore, under these drier conditions, Salmonella persisted to a greater extent than L. monocytogenes, and the desiccation resistance of Salmonella appeared to convey cross-protection to ammonia. Salmonella persisted longer in compost mixtures prepared with aged chicken litter compared with fresh chicken litter, whereas E. coli O157:H7 survived to similar extents in compost mixtures prepared with either fresh or aged cow manure. The different responses observed when different sources of manure were used in compost mixtures reveal that guidelines with times required for pathogen inactivation in compost mixtures stored at sublethal temperatures should be dependent on the source of nitrogen, i.e., type of animal manure, present.

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Inactivation of Pathogens during Aerobic Composting of Fresh and Aged Dairy Manure and Different Carbon Amendments

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-194 ◽

2014 ◽

Vol 77 (11) ◽

pp. 1911-1918 ◽

Cited By ~ 8

Author(s):

MARILYN C. ERICKSON ◽

JEAN LIAO ◽

XIUPING JIANG ◽

MICHAEL P. DOYLE

Keyword(s):

C:N Ratio ◽

Heat Exposure ◽

Ammonia Concentration ◽

Dairy Manure ◽

Physical Parameters ◽

Pathogen Inactivation ◽

Factors Affecting ◽

Initial Carbon ◽

Peanut Hulls ◽

Pathogen Reduction

Two separate studies were conducted to address the condition and the type of feedstocks used during composting of dairy manure. In each study, physical (temperature), chemical (ammonia, volatile acids, and pH), and biological (Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7) parameters were monitored during composting in bioreactors to assess the degree to which they were affected by the experimental variables and, ultimately, the ability of the chemical and physical parameters to predict the fate of pathogens during composting. Compost mixtures that contained either aged dairy manure or pine needles had reduced heat generation; therefore, pathogen reduction took longer than if fresh manure or carbon amendments of wheat straw or peanut hulls were used. Based on regression models derived from these results, ammonia concentration, in addition to heat, were the primary factors affecting the degree of pathogen inactivation in compost mixtures formulated to an initial carbon-nitrogen (C:N) ratio of 40:1, whereas, the pH of the compost mixture along with the amount of heat exposure were most influential in compost mixtures formulated to an initial C:N ratio of 30:1. Further studies are needed to validate these models so that additional criteria in addition to time and temperature can be used to evaluate the microbiological safety of composted manures.

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Influence of Substrate Load on Polyhydroxyalkanoates (Pha) Accumulation by Unenriched Mixed Cultures from Excess Sludge Fermentation Liquid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.455-456.856 ◽

2012 ◽

Vol 455-456 ◽

pp. 856-861

Author(s):

Meng Meng Cai ◽

Fu Yi Cui ◽

Qing Liang Zhao ◽

Hong Chua

Keyword(s):

Growth Rate ◽

Uptake Rate ◽

Volatile Fatty Acids ◽

C:N Ratio ◽

Mixed Cultures ◽

Carbon Substrate ◽

Biomass Growth ◽

Excess Sludge ◽

Initial Carbon ◽

Storage Rate

To reduce the production cost of polyhydroxyalkanoates (PHA) and disposal amount of excess sludge simultaneously, volatile fatty acids (VFAs) from alkaline excess sludge fermentation was used as carbon sources to synthesize PHA by unenriched mixed cultures. Released phosphorus and residual ammonium in the fermentative VFAs was controlled by adding magnesium to form struvite precipitation. Four VFAs liquids obtained was used to test the influence of initial carbon load and carbon to nitrogen ratio (C:N ratio) on the VFAs uptake rate, PHA storage rate and biomass growth rate. Results show that higher initial carbon substrate load results in relatively higher VFAs uptake rate and higher PHA storage rate, while higher initial C:N ratio results in relatively lower biomass growth rate from VFAs. VFAs generated from thermophilic alkaline sludge fermentation were a suitable carbon source for PHA production by mixed cultures.

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Microbial Production of Polyhydroxy alkanoates (PHAs) using Kitchen Waste as an Inexpensive Carbon Source

Biosciences Biotechnology Research Asia ◽

10.13005/bbra/2733 ◽

2019 ◽

Vol 16 (1) ◽

pp. 155-166 ◽

Cited By ~ 2

Author(s):

Rayasam Vijay ◽

Kumar Tarika

Keyword(s):

Carbon Source ◽

Reference Strain ◽

C:N Ratio ◽

Treatment Plant ◽

Orange Peel ◽

Cupriavidus Necator ◽

Effluent Treatment ◽

Bacterial Isolates ◽

Bacterial Strains ◽

Onion Peel

It is a well-known fact that Polyhydroxyalkanoates (PHAs) have the potential to replace petrochemical based plastics. The purpose of our study is to devise a method to reduce substrate cost and produce PHA from our own microbial isolates selected after isolation from polluted environments. A comparative study was done with the reference bacterium Cupriavidus necator. Fourteen bacterial strains were isolated from Polluted Landfills and Effluent Treatment Plant. Four bacterial isolates having the ability to produce PHA were selected. Orange peel and Onion peel were substituted for carbon source in the medium and all the bacterial isolates along with the reference strain were studied for the maximum ability to produce PHA from these wastes respectively. The reference strain Cupriavidus necator yielded 82% PHA in 1:1 C:N ratio utilizing onion peel and 64% in 4:1 C:N ratio utilizing orange peel at 96h of incubation respectively. The best results obtained on onion peels as carbon source were by the isolate Bacillus subtilis JCM 1465 with 89% in 3:1 at 48h of incubation. Maximum PHA production obtained by bacterial isolate Bacillus siamensis PD- A10 using orange peel as carbon source was upto 82% in 1:1 at 24h of incubation.

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Lovastatin Production by Pleurotus ostreatus: Effects of the C:N Ratio

Zeitschrift für Naturforschung C ◽

10.1515/znc-2006-1-217 ◽

2006 ◽

Vol 61 (1-2) ◽

pp. 95-98 ◽

Cited By ~ 11

Author(s):

Julio Alarcón ◽

Sergio Águila

Keyword(s):

Carbon Source ◽

Nitrogen Source ◽

Pleurotus Ostreatus ◽

Organic Nitrogen ◽

C:N Ratio ◽

Maximum Value

Abstract The types of carbon source and nitrogen source used as well as the C:N ratio in the medium influenced lovastatin production by Pleurotus ostreatus. The maximum value of the lovastatin yield was obtained in a medium that contained organic nitrogen

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Polyhyrdoxybutyrate production by Bacillus marcorestinctum using a Cheaper substrate and its electrospinned blends with polymer

10.1101/680124 ◽

2019 ◽

Author(s):

Swetha Narayankumar ◽

Neethu K. Shaji ◽

Veena gayathri Krishnaswamy

Keyword(s):

Carbon Source ◽

Large Scale ◽

C:N Ratio ◽

Scale Up ◽

Production Costs ◽

Scale Production ◽

Transmission Electron ◽

Large Scale Production ◽

Dry Cell Weight ◽

Alternative Carbon Source

ABSTRACTPoly(hydroxybutyric acid) (PHB) and other biodegradable polyesters are promising candidates for the development of environment-friendly and completely biodegradable plastics. One of the major drawbacks in the production of PHB is production costs, since it requires large amount of carbon source. This calls for cheaper substrates that can be used as an alternative carbon source such as agro-industrial residues. In this study, cane molasses was used as an additional carbon source at 2% concentration along with glucose for large scale production of PHB. Ammonium nitrate was used as the nitrogen source and the C:N ratio was maintained at 1:15. The maximum production of PHB was obtained at 24hours of growth which was found to be 0.5g/L and had a dry cell weight of 3.7g/ L.The PHB produced was further analysed by GC-MS Analysis and Transmission Electron Microscopy (TEM).The obtained PHB from scale-up studies were further electrospinned using different blends of polymers.

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