Effect Of Nitrogen Sources Research Articles

Interactive effects of temperature and nitrogen source on the elemental stoichiometry of a polar diatom

AbstractA recent study hypothesized that the near‐zero temperatures that generally prevail in Arctic waters negate the influence that different nitrogen (N) sources can otherwise have on the growth and elemental stoichiometry of marine micro‐algae. Here we test this hypothesis experimentally by evaluating how temperature (0–9°C) affects the growth and elemental stoichiometry of an ecologically relevant Arctic diatom Chaetoceros gelidus growing on different N sources (ammonium, nitrate, urea) at saturating irradiance. Following an initial acclimation period in which steady growth rates were achieved under each experimental treatment, changes in cellular concentrations of chlorophyll a and particulate carbon (C), nitrogen (N), phosphorus (P), and biogenic silica (Si) were monitored. While N source effects on growth rate became manifest as temperature rose above 0°C, the estimated optimal growth temperature was similar in all cases (Topt = 8.3°C). A positive effect of temperature on the N : P ratio occurred only at 6°C. Above this temperature, the N : P ratio decreased to values close to those observed at 0°C and 3°C. By contrast, the C : N ratio remained nearly invariant between 0°C and 6°C but increased substantially at 9°C. Overall, the results suggest that the presently widespread and successful diatom C. gelidus possesses the ability to remain competitive despite ongoing environmental changes and that its responses to warming and the availability of different N sources may impact elemental fluxes in the future.

Effect of Irrigation, Nitrogen Sources, and Metribuzin on Performance of Maize and Its Weeds

ABSTRACT Exploiting water and nutrients by crop plants is limiting by abundance of undesirable plant species viz weeds due to their competitiveness ability, affecting crop productivity and quality. Thus, over two seasons of 2017 and 2018, field experiment was carried out at the Experimental Farm of Faculty of Agriculture, Ain Shams University, Egypt to study the response of maize grain yield and its nutrient constituents and associated weeds to two irrigation intervals (every 15 and 22 days), three weed control treatments (hoeing twice, metribuzin, and unweeded) as well as three nitrogen forms (ammonium nitrate, ammonium sulfate, and urea). The tested factors distributed in a strip plots design with four replications. The results showed that dry weight of grasses (56.1 g m−2) and total weeds (67.2 g m−2) were lower with irrigation every 15 day. Irrigation every 15 day gave the maximum increase in plant height (233 cm), ear length (18.4 cm), ear diameter (4.7 cm), 100 grain weight (28.0 g), grain yield (7.58 ton ha−1) and leaf P (0.29%) and K (2.07%) contents. Hoeing gave the lowest biomass of grasses, total weeds and weeds potassium content, while metribuzin was the superior in diminishing broadleaf weed biomass. Hoeing was as similar as metribuzin as in enhancing plant height, ear length, 100 grain weight and grain yield ton ha–1. Nitrogen (N) form had no significant effect on weed biomass. However, ammonium nitrate was the most effective form at promoting 100 grain weight, ear length, grain yield ton ha–1 and maize leaf potassium content. Results exhibited that irrigating maize fields every 15 day × hoeing or metribuzin × ammonium sulfate–N could be a combatable and integrative pattern for diminishing weed growth and keeping crop productivity.

Nitrogen Isotopes of Sinking Particles Reveal the Seasonal Transition of the Nitrogen Source for Phytoplankton

AbstractIn the high‐productivity subarctic ocean, phytoplankton growth is assumed to rely mainly on nitrate, based on snapshot observations conducted in spring or summer. However, the year‐round utilization of nitrate and ammonium by phytoplankton remains unexplored. Here, we show the seasonal transition of the dominant nitrogen source for phytoplankton by using the nitrogen isotopic composition (δ15N) of nitrate, ammonium, and sinking particles in the northwestern North Pacific. To decouple the combined effects of nitrogen sources for phytoplankton and subsequent trophic transfers in δ15N of sinking particles, we used compound‐specific δ15N analysis of amino acids (δ15NAA) in sinking particles. The seasonal change in δ15NAA revealed that most of the seasonal variation in δ15N of sinking particles arose from changes in the availability of nitrogenous nutrients in the euphotic layer. The δ15N of sinking particles suggested that the dominant nitrogen source for phytoplankton switches from nitrate to ammonium in autumn.

Process intensification for the enhancement of growth and chlorophyll molecules of isolated Chlorella thermophila: A systematic experimental and optimization approach

In our current work, we have optimized six physicochemical parameters (light intensity, light period, pH, inoculum size, culture period, and salt concentration) toward growth and chlorophyll synthesis using isolated fresh water microalgae Chlorella thermophila [contains ∼6% (w/w on dry biomass basis) chlorophyll]. Here, both experimental and computational [Taguchi orthogonal array (TOA), artificial neural network (ANN), and genetic algorithm (GA)] approaches were employed for the process intensification. Results revealed that the content of biomass and chlorophyll were enhanced by 118% and 95%, respectively, with productivity enhancement of 30% for biomass and 61% for chlorophyll from the optimization of physicochemical parameters. Further, optimum light intensity was found to be 128 µmol m−2 s−1 after conducting experiments in optimized chemical and physicochemical conditions, contributing to the enhancement of productivity of 46% for biomass and 106% for chlorophyll. Urea was found to be the most effective nitrogen source with an increase of 70% and 160% biomass and chlorophyll productivity, respectively. Moreover, sucrose as a carbon source contributed to an increase of 97% and 264% biomass and chlorophyll productivity.

Poultry litter and nitrogen fertilizer effects on productivity and nutritive value of crabgrass

AbstractCrabgrass (Digitaria spp.) is deemed as a productive and nutritious warm‐season annual forage for livestock in the U.S. transition zone. However, there is limited information about nitrogen (N) source and rate effects on productivity and nutritive value of crabgrass in North Carolina. Herbage accumulation (HA), N removal, crude protein (CP), total digestible nutrients (TDN), and tissue nitrate (NO3−) concentrations were evaluated for 2 yr (2020 and 2021) in two physiographic regions (Piedmont and Coastal Plain). Treatments were five rates of chemical N fertilizer (up to 480 kg N ha−1), five rates of plant‐available N from broiler poultry litter (up to 472 and 399 kg N ha−1 in 2020 and 2021, respectively), and one control (zero N). Overall crabgrass responses were not different between N sources. At Coastal Plain, HA increased from 4,990 kg dry matter (DM) ha−1 and plateaued at 7,136 kg DM ha−1 at an agronomic optimum N rate (AONR) of 198 (SE = 49) kg N ha−1. At Piedmont, HA responses were erratic, estimation of an AONR was not possible, and HA values were approximately half or less to those at Coastal Plain. Removal of N was linearly associated with HA. Increasing N rate had a marginal positive effect on CP (ranged from 126 to 154 g kg−1) and no effect on TDN (averaged 626 g kg−1). Tissue NO3− values were below the toxic threshold for feeding livestock. Poultry litter is an effective N source for crabgrass. Nitrogen rate effects were more apparent on crabgrass’ productivity; nutritive value was generally high regardless of N rate and source.

Effects of Nitrogen Source and Rate on Soybean Yield and Quality

ABSTRACT The poultry industry in North Carolina (NC) has increased substantially over the past few decades, which has led to widespread availability of poultry litter. While many grain producers in NC utilize litter in their fertilization programs, it is typically applied to the corn or wheat crops that are in the rotation with soybean, instead of directly prior to soybeans. However, there is interest in application to soybean. Therefore, three field sites were established across NC in both 2019 and 2020, with four replicates of 11 treatments: four litter rates (22.4, 44.8, 89.7 and 134.5 Mg/hectare), six inorganic nitrogen (N) fertilizer rates (16.8, 33.6, 67.3, 134.5, 201.8, and 269.0 kg N/hectare), and a control. The impact of these treatments on biomass production, tissue N, plant population, yield, and grain quality were investigated. There was no significant effect on yield in 2019; however, there was a significant effect on yield in 2020, showing a negative correlation with inorganic N fertilizer in Plymouth and a 22% reduction in yield over the range of inorganic N treatments. It is possible there was an increased salt effect in these plots, as there was a negative response in plant population at five of six site years. While there was a positive correlation between grain protein and increasing inorganic N rate, growers are not paid based on grain quality. The results of this study suggest N application at planting is not beneficial for growers, but litter could be applied to meet soybean phosphorus or potassium demands.

Optimization of Submerged Fermentation Parameters for Enhanced Lipase Production from Newly Isolated Lipolytic Yeasts using Agro Waste Substrates

Fungi are currently recognized as the most preferred sources of lipase due to their ability to produce copious amount of extracellular lipase with lower production’s and extraction’s costs. Lipase production was carried out in agro wastes formulated-liquid fermentation media at 300C, at 130rpm, at initial pH of 7 for 96 hours using newly isolated LipA gene identified yeasts [Pichia kudriavzevii ENS1 [Accession No: OL546800], Candida orthopsilosis PMS3 [Accession No: OL546803] and Saccharomyces cerevisiae PMS8 [Accession No: OL546805] at inoculum size of 2%. Agrowastes such as Mango kernel and orange peel were used as alternative carbon sources; beans hull and groundnut shell as nitrogen sources while lipidic sources such as olive oil, soyabeans oil, palm oil, groundnut oil and coconut oil were used as inducers. Single factor optimization process was carried out to determine the effects of carbon sources, nitrogen sources, inducers, incubation time, inoculum size, pH and carbon: nitrogen ratio on lipase production and cell growth. Extraction by filtration, centrifugation and acetone precipitation; Quantitative lipase assay using titrimetric method and Cell growth by measuring optic density at 600nm were done. Proximate analysis of the agro-waste substrates showed higher percentage of carbohydrate and crude fat in mango kernel powder at 68.05±0.56% and 19.54±0.62% while groundnut shell recorded higher crude protein at 11.63±0.05%. Single factor optimization study showed optimum lipase production and cell growth at 50.83±1.18u/ml/min and 0.69±0.00[OD] with Candida orthopsilosis PMS3[Accession No: OL546803] using hot water treated mango kernel hydrolysate as carbon source. The results from this study showed that mango kernel would be an economical alternative carbon source for industrial-scale lipase production.

An NmrA-Like Protein, Lws1, Is Important for Pathogenesis in the Woody Plant Pathogen Lasiodiplodia theobromae.

The NmrA-like proteins have been reported to be important nitrogen metabolism regulators and virulence factors in herbaceous plant pathogens. However, their role in the woody plant pathogen Lasiodiplodia theobromae is less clear. In the current study, we identified a putative NmrA-like protein, Lws1, in L. theobromae and investigated its pathogenic role via gene silencing and overexpression experiments. We also evaluated the effects of external carbon and nitrogen sources on Lws1 gene expression via qRT-PCR assays. Moreover, we analyzed the molecular interaction between Lws1 and its target protein via the yeast two-hybrid system. The results show that Lws1 contained a canonical glycine-rich motif shared by the short-chain dehydrogenase/reductase (SDR) superfamily proteins and functioned as a negative regulator during disease development. Transcription profiling revealed that the transcription of Lws1 was affected by external nitrogen and carbon sources. Interaction analyses demonstrated that Lws1 interacted with a putative GATA family transcription factor, LtAreA. In conclusion, these results suggest that Lws1 serves as a critical regulator in nutrition metabolism and disease development during infection.

EFECTOS DE LAS FUENTES NITROGENADAS EN LA MORFOFISIOLOGÍA, PRODUCCIÓN Y CALIDAD DE CACAO (Theobroma cacao L.) CCN-51 EN EL SUR DE LA AMAZONIA ECUATORIANA

<p><strong>Background</strong>. In the new global economy, cocoa is an important crop. However, far too little attention has been paid to the nutritional aspects. On the other hand, nitrogen is the most important nutrient in crop production, and mineral nitrogen fertilizers are the most widely used by farmers. Improving the efficiency of nitrogen uptake and utilization could potentially increase crop yields and quality, as well as reduce nitrogen fertilization and environmental pollution. <strong>Objective.</strong> Therefore, the objective of this study was to evaluate the effect of three nitrogen sources on morphological characteristics, yield and quality of CCN-51 cocoa, and soil chemical characteristics in the Ecuadorian Amazon. <strong>Methodology.</strong> A randomized design was established with 4 treatments with the same N dose, but varying the source (amide: urea, calcium nitrate, NC, and ammonium sulfate, SA), plus a control without N application. The investigated variables are soil chemical characteristics, shoot growth, fruit morphology, seed chemical characteristics, production and yield estimates, and agronomic efficiency of the sources. <strong>Results.</strong> NC maintained soil pH at 5.29 points compared to SA and urea, which acidified at a higher rate (4.32 and 3.96), leading to an increase of N and a decrease Ca in the soil. SA increased the fat content in the cocoa seed (54.1 %), with a higher number of fruits per plant (16.7) and, therefore, a better yield (0.799 t/ha). <strong>Implications.</strong> These results provide basic information on the nitrogen source effects and cocoa nutrition to be considered for future research. <strong>Conclusion.</strong> The findings suggested that NC conserves soil pH better than the other sources. SA increases production and fat content, so it can be considered the most efficient. </p>

Factors Influencing the Production of Extracellular Polysaccharides by the Green Algae Dictyosphaerium chlorelloides and Their Isolation, Purification, and Composition.

The freshwater green microalgae, Dictyosphaerium chlorelloides (CCALA 330), has the ability to produce extracellular polysaccharides (EPS). Conditions for optimum growth and EPS overproduction were determined in laboratory-scale tubular photobioreactors (PBR) with a working volume of 300 mL. Multiple limitations in nutrient supply were proven to be an effective method for EPS overproduction. Salinity stress was also applied to the culture, but no significant increase in EPS production was observed. The effects of different nitrogen sources were examined and the microalgae exhibited the fastest growth and EPS production in medium containing ammonium nitrate. Under determined optimal conditions, EPS concentration reached 10 g/L (71% of the total biomass) and a total biomass of 14 g/L at the end of 17 days cultivation. Pilot-scale cultivation was also carried out in a column type airlift photobioreactor (PBR) with a working volume of 60 L. A new and efficient methodology was developed for separating cells from the EPS-containing culture broth. Due to the strong attachment between cells and EPS, high-pressure homogenization was carried out before a centrifugation process. The EPS in the supernatant was subsequently purified using ultrafiltration. The green microalgae Dictyosphaerium chlorelloides may therefore be appropriate for the commercial production of EPS.

Artificial neural network modeling and statistical optimization of medium components to enhance production of exopolysaccharide by Bacillus sp. EPS003

Microbial Exopolysaccharides (EPS) have a wide range of applications in food, cosmetics, agriculture, pharmaceutical industries, and environmental bioremediation. The present study aims at enhancing the production of EPS from a soil-isolate Bacillus sp. EPS003. Effects of carbon and nitrogen sources and process conditions were evaluated one factor at a time. Box-Behnken design has been used and a 2.5-fold increase in yield is reported after optimizing the most influential parameters sucrose, yeast extract, and peptone as identified by the Plackett-Burman method. An artificial neural network (ANN) with two different topologies (EPS-NN1 and EPS-NN2) was developed. On comparing prediction accuracy, EPS-NN2 formulated as one input layer with four input variables (sucrose, yeast extract, peptone, biomass), a single hidden layer with seven neurons and EPS yield in the output layer showed a high coefficient of determination (R 2—0.98) and low error (NRMSE—0.024). This study concludes that the consideration of biomass value has increased the prediction accuracy of the model.

Potential of the Liquid Fermentation of Fishery Waste by Paenibacillus elgii for Metalloprotease Production

This study attempted to use fishery processing wastes to produce protease by Paenibacillus elgii TKU051. Of the tested wastes, tuna head powder (THP) was found to be the most effective carbon and nitrogen (C/N) source, and the optimal conditions were as follows: 0.811% THP, 0.052% K2HPO4, 0.073% MgSO4, initial pH of 8.96, incubation temperature of 31.4 °C, and incubation time of 3.092 days to achieve the maximum protease activity of 2.635 ± 0.124 U/mL. A protease with a molecular weight of 29 kDa was purified and biochemically characterized. Liquid chromatography with tandem mass spectrometry analysis revealed an amino acid sequence of STVHYSTR of P. elgii TKU051 protease, suggesting that the enzyme may belong to the M4 family of metalloproteases. The optimal activity of the enzyme was achieved at 60 °C and pH 8. P. elgii TKU051 protease was strongly inhibited by ethylenediaminetetraacetic acid and 1,10-phenanthroline, indicating its precise metalloprotease property. P. elgii TKU051 protease displayed the activity toward casein and raw fishery wastes such as tuna heads, tuna viscera, shrimp heads, and squid pens. Finally, the purified P. elgii TKU051 protease could improve the free-radical scavenging activity of fishery wastes. In short, P. elgii TKU051 has potential application in eco-friendly approaches to efficiently convert fishery wastes to metalloprotease.

Erratum to: Improving productivity of managed potato cropping systems in Eastern Canada: Crop rotation and nitrogen source effects

Agronomy JournalVolume 114, Issue 4 p. 2618-2618 ERRATUMFree Access Erratum to: Improving productivity of managed potato cropping systems in Eastern Canada: Crop rotation and nitrogen source effects This article corrects the following: Improving Productivity of Managed Potato Cropping Systems in Eastern Canada: Crop Rotation and Nitrogen Source Effects Judith Nyiraneza, Rick D. Peters, Vernon A. Rodd, Mark G. Grimmett, Yefang Jiang, Volume 107Issue 4Agronomy Journal pages: 1447-1457 First Published online: July 1, 2015 First published: 23 August 2022 https://doi.org/10.1002/agj2.21104AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat J. Nyiraneza, R.D. Peters, V.A. Rodd, M.G. Grimmett and Y. Jiang Erratum for “Improving productivity of managed potato cropping systems in Eastern Canada: Crop rotation and nitrogen source effects” by Nyiraneza et al., Agron. J. 107:1447–1457. Under the table 3, amount of N and C in different fractions are reported in g kg−1 which is wrong. The correct unit should be mg. REFERENCE Nyiraneza, J., Peters, R. D., Rodd, V. A., Grimmett, M. G., & Jiang, Y. (2015). Improving productivity of managed potato cropping systems in Eastern Canada: Crop rotation and nitrogen source effects. Agronomy Journal, 107, 1447––1457. https://doi.org/10.2134/agronj14.0430 Volume114, Issue4July/August 2022Pages 2618-2618 ReferencesRelatedInformation

Bacteria Halotolerant from Karst Sinkholes as a Source of Biosurfactants and Bioemulsifiers.

Halotolerant bacteria with biosurfactant (BS) and bioemulsifiers (BE) activity can coexist in Karstic sinkholes with marine influence. Two sinkholes in the Yucatan peninsula were selected to isolate bacteria with BE and BS activity stable in NaCl. The optimal time, the effect of nitrogen and carbon source in the medium, and the conditions (agitation, pH and salinity) for the production of BS and BE compounds in planktonic and sessile (stimulate the formation of biofilms in cell roller) culture were determined. Eighty strains showed the highest emulsification activity (EI24 ≥ 50%) and drop-collapse ≥ 4 mm. 87% of the strains are moderately halotolerant, and 21% bordered the limit of extreme halotolerance. Twenty-four strains maintained or improved their BS and BE activity under salinity conditions at 5% and 10%, being the most active genera Bacillus, Paenibacillus and Lysinibacillus, identified by sequencing of the 16S rRNA gene. The results show that the nitrogen source positively affects the BS and BE activity, regardless of the type of culture. The sessile culture markedly stimulated BS activity with significant differences. However, we did not find a greater influence on the culture conditions. The results suggest that halotolerant bacteria from sinkholes could be implemented in bioremediation and other biotechnological applications.

EFFECTS OF DIFFERENT NITROGEN SOURCES ON TURF QUALITY AND PLANTS GROWTH OF SOME WARM-SEASON TURFGRASSES

This research was conducted to determine the effects of different nitrogen sources and rates on some warm-season turfgrasses under Mediterranean-type climate conditions in 2017-2018. The experimental design was a split-split plot with design with three replicates; turfgrass species as the main plot, nitrogen sources as the subplots, and nitrogen doses as the sub subplots. The main plots consist of four nitrogen sources: two slow-release fertilizers, one organomineral fertilizer, and one sewage sludge. Subplots consist of three warm-season turfgrass species; zoysiagrass (Zoysia japonica Steud.), hybrid Bermudagrass (Cynodon transvaalensis x Cynodon dactylon), seashore paspalum (Paspalum vaginatum Sw.), and one cool-season turfgrass species, tall fescue (Festuca arundinacea Schreb.). The nitrogen doses were as follows; 0.0, 2.0, 3.0 and 4.0 g m-2. Turf color and quality were evaluated visually monthly. Also, clipping weight is determined. According to the result, slow-release and organomineral fertilizers can be assessable as N sources that will meet the nutritional needs of the turfgrasses. Zoysiagrass and seashore paspalum showed almost equivalent scores and gave sufficiently dark turf color and quality. Turfgrass should be fertilized at least with 3.0 g m−2 N to provide acceptable turf color and quality.

The source of carbon and nitrogen differentially affects the survival of Neisseria meningitidis in macrophages and epithelial cells

Neisseria meningitidis is a commensal of human nasopharynx which under certain unidentified conditions could lead to fulminant meningitis or sepsis. Availability of nutrients is essential for bacterial growth and virulence. The metabolic adaptations allow N. meningitidis to utilize host resources, colonize and cause virulence functions which are a crucial for the invasive infection. During colonization meningococci encounters a range of microenvironments involving fluctuations in the availability of carbon and nitrogen source. Therefore, the characterization of virulence factors of N. meningitidis under different microenvironmental conditions is a prime requisite to understand pathogenesis; however, the role of nutrients is not well understood. Here, we explore the expression of virulence phenotype leading to symptomatic behaviour as affected by available carbon and nitrogen sources. We evaluate the effect of carbon or nitrogen source on growth, adhesion to epithelial cells, macrophage infectivity, capsule formation and virulence gene expression of N. meningitidis. It was found that lactate, pyruvate, and acetate facilitate survival of N. meningitidis in macrophages. While in epithelial cells, the survival of N. meningitidis is negatively affected by the presence of lactate and pyruvate.

Production of Citric Acid from Fruit Waste of Banana Using Aspergillus niger

In this study citric acid production was carried by using banana waste from Aspergillus niger. Effect of different carbon and nitrogen sources like glucose, sucrose, yeast extract and peptone were studied on production. Citric acid production was recorded from 3rd day of incubation upto 5th day. The percentage of citric acid ranged from 0.028% to 0.480% maximum production was obtained from glucose as carbon source i.e; 0.480% on 5th day and maximum production was obtained from yeast extract as nitrogen source i.e; 0.168% on 5th day. Keywords: Citric acid, Aspergillus niger

The Effect of Growth Conditions on Mycelial Run of Oyster Mushrooms spp. (Pleurotus spp.): Implication for Agricultural Practices

Background: The Pleurotus genus is one of the most investigated white-rot fungus due to its excellent ligninolytic characteristics. It is a tasty mushroom that also has a number of biological impacts due to the presence of essential bioactive compounds. Many usual fermentation parameters affect lignocellulolytic enzymes in basidiomycete fungi, such as medium composition, carbon-to-nitrogen ratio, pH, temperature, air composition etc. The survival and multiplication of Pleurotus mushrooms is dependent on a number of factors, which may function independently or interactive effect on the growth of mushroom. Grasp the difficulty of treating Pleurotus species mushrooms necessitates a fundamental understanding of their physical, chemical and biological characteristics. Methods: In this study, the effects of culture media, temperature, carbon sources, nitrogen sources, grain sources and agricultural waste as lignocellulosic substrate on the mycelium growth of five species of Pleurotus species for spawn production were studied. Several trials were designed to evaluate factors affecting mycelium growth of five oyster mushroom species. The experiments were conducted during October to February in the year 2019 to 2021. The experiments were carried out in three replications per treatment. Result: The results of the experiment indicated that potato dextrose agar (PDA) and Malt extract agar (MEA) were the most suitable media for the mycelium growth of all oyster mushrooms. The optimal temperature for mycelium growth of all the oyster mushroom species was obtained at 25±2oC. Mycelium growth of all the studied oyster mushroom was improved by carbon sources such as dextrose and glucose. The nitrogen source such as ammonium chloride and ammonium sulfate also gave the greatest values in mycelium colony diameter of mushroom. Wheat was found to be favourable for mycelium growth of all the oyster mushroom species. In addition, paddy straw and sugarcane residue were selected as suitable lignocellulosic substrate sources for mycelium growth of all the studied oyster mushrooms.

Effects of Non-Protein Nitrogen Sources on In Vitro Rumen Fermentation Characteristics and Microbial Diversity

Here, the effects of non-protein nitrogen sources on fermentation parameters and microbial diversity were explored using three fistula goats as rumen fluid donors. The experiments involved six fermenters in a replicated 3 × 3 Latin square design with three dietary non-protein sources [ammonium chloride (A), biuret (B), and glutamine (G)] as treatment factors. A dual-flow continuous culture fermentation system was used. Microbial protein content in group B was significantly lower than that in the other two groups (P < 0.05). Ammonia nitrogen concentration significantly differed among the three groups (P < 0.01), following the order of G > A > B group. The acetate-to-propionate ratio in group G was significantly lower than that in the other two groups (P < 0.01). At the phylum level, the relative abundances of Cyanobacteria, Elusimicrobia, and Armatimonadetes were the highest in group G, being significantly higher than those in group B (P < 0.05). At the genus level, the relative abundance of Ruminococcus_1 was significantly higher in group A than in group B (P < 0.05). Overall, glutamine shifted the fermentation pathway from acetate to propionate, and the lower microbial crude protein content and relative abundances of the major fiber-degrading bacteria Ruminococcus_1 and protein-degrading bacteria Prevotellaceae_UCG-001 in group B indicate that biuret is not suitable as a dietary non-protein nitrogen source.

SCREENING OF FACTORS RESPONSIBLE FOR CONVERSION OF MAIZE STRAW INTO BIOETHANOL

Maize straw is a lignocellulosic waste that is annually added to the environment as pollutant because its accumulation constitutes a nuisance and in addition, its reducing sugar is not readily released. Pretreatment of maize straw makes its reducing sugar available for fermentation into bio-products such as bioethanol production under optimized conditions. This work aimed at determining the effect of different parameters on ethanol production by Saccharomyces cerevisiae from pretreated maize straw. Effects of pH, temperature, sugar concentration, nitrogen source, and inoculum load/sizes on ethanol yield of pretreated maize straw by S. cerevisiae SA01 and S. cerevisiae SA02 for optimum ethanol production were determined using standard methods. Ethanol content was estimated using a gravimetric method. The optimum ethanol production (1.97 g/L) was obtained at pH 5.5 while highest ethanol content (2.76 and 2.37 g/L) was at 30 °C by S. cerevisiae SA01 and S. cerevisiae SA02, respectively. The glucose concentration of 2 % supported the highest ethanol production (3.95 g/L) by S. cerevisiae SA02. Corn steep liquor was the best among the nitrogen sources used and increased the ethanol yield of S. cerevisiae SA01 and S. cerevisiae SA02 by 300 and 661 %, respectively. One percent of 1.0 MacFarland standard of both yeasts supported the highest ethanol production (14.99 g/L) from pretreated maize straw. Bio-conversion of maize straw to substrate for bioethanol production at optimized conditions will reduce environmental pollution, production cost and increase energy sources.