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2022 ◽  
Author(s):  
Paul M Berube ◽  
Tyler J O'Keefe ◽  
Anna N Rasmussen ◽  
Sallie W Chisholm

Prochlorococcus is an abundant photosynthetic bacterium in the oligotrophic open ocean where nitrogen (N) often limits the growth of phytoplankton. Prochlorococcus has evolved into multiple phylogenetic clades of high-light (HL) adapted and low-light (LL) adapted cells. Within these clades, cells encode a variety of N assimilation traits that are differentially distributed among members of the population. Among these traits, nitrate (NO3-) assimilation is generally restricted to a few clades of high-light adapted cells (the HLI, HLII, and HLVI clades) and a single clade of low-light adapted cells (the LLI clade). Most, if not all, cells belonging to the LLI clade have the ability to assimilate nitrite (NO2-), with a subset of this clade capable of assimilating both NO3- and NO2-. Cells belonging to the LLI clade are maximally abundant at the top of the nitracline and near the primary NO2- maximum layer. In some ecosystems, this peak in NO2- concentration may be a consequence of incomplete assimilatory NO3- reduction by phytoplankton. This phenomenon is characterized by a bottleneck in the downstream half of the NO3- assimilation pathway and the concomitant accumulation and release of NO2- by phytoplankton cells. Given the association between LLI Prochlorococcus and the primary NO2- maximum layer, we hypothesized that some Prochlorococcus exhibit incomplete assimilatory NO3- reduction. To assess this, we monitored NO2- accumulation in batch culture for 3 Prochlorococcus strains (MIT0915, MIT0917, and SB) and 2 Synechococcus strains (WH8102 and WH7803) when grown on NO3- as the sole N source. Only MIT0917 and SB accumulated external NO2- during growth on NO3-. Approximately 20-30% of the NO3- transported into the cell by MIT0917 was released as NO2-, with the balance assimilated into biomass. We further observed that co-cultures using NO3- as the sole N source could be established for MIT0917 and a Prochlorococcus strain that can assimilate NO2- but not NO3-. In these co-cultures, the NO2- released by MIT0917 was efficiently consumed by its partner strain during balanced exponential growth. Our findings highlight the potential for emergent metabolic partnerships within Prochlorococcus populations that are mediated by the production and consumption of the N cycle intermediate, NO2-.


2022 ◽  
Vol 951 (1) ◽  
pp. 012064
Author(s):  
N A Fitriyanto ◽  
Y Ramadhanti ◽  
Rismiyati ◽  
I Rusyadi ◽  
A Pertiwiningrum ◽  
...  

Abstract The poultry feathers have a very high protein content due to it consists of 90% of crude protein, and it is an ideal material to obtain keratin protein. Due to Keratin’s difficulties and time-consuming decomposition, further processing is needed to degrade Keratin into simpler proteins that can be used as an alternative N-source. This study was aimed to evaluate the keratin hydrolysate from poultry feathers prepared by acidic (HCl) and alkaline (NaOH) compound utilization and its potency as the substrate medium for growth keratinolytic bacteria at a laboratory scale. Poultry feathers, including kampung (local breed) chicken feathers, layer chicken feathers, and local goose treat with HCL 12% and NaOH 20%. The results of the hydrolysate of poultry feathers using 12% HCl showed no significant changes. Visually, the feathers of birds that have been treated with 12% HCl show a colour change to brownish-yellow. The results of hydrolysis using NaOH showed better results than HCl for producing feather meals. The highest yield has occurred at local goose feathers at 95.7%, followed by Kampung and Layer chicken feathers at 93.17% and 78,75%. Based on the viability test, three indigenous strains (Bacillus cereus TD5B, B. cereus LS2B and Pseudomonas sp. PK4) grew in a medium with a substrate of kampung chicken feathers, layer chickens, and local goose feathers. It can be concluded that the hydrolysed poultry feathers made by NaOH 20% preparation had a potency as N-source in the bacterial growth medium.


Author(s):  
Chaiartid Inkham ◽  
Kanokwan Panjama ◽  
Takashi Sato ◽  
Soraya Ruamrungsri
Keyword(s):  
N Uptake ◽  

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1808
Author(s):  
Mengyun Chen ◽  
Kaikai Zhu ◽  
Pengpeng Tan ◽  
Junping Liu ◽  
Junyi Xie ◽  
...  

Although ammonia–nitrogen (NH4+–N) and nitrate–nitrogen (NO3−–N) are the two main forms of N absorbed and utilized by plants, the preferences of plants for these forms are still unclear. In this study, we analyzed the growth, photosynthesis, and nutrients of pecan under different NH4+:NO3− ratios (0/0, 0/100, 25/75, 50/50, 75/25, 100/0) by indoor aerosol incubation. The results showed that additions of different N forms promoted the growth and development of pecan seedlings. When NO3−–N was used as the sole N source, it significantly promoted the ground diameter growth of pecan and increased the leaf pigment content and photosynthetic rate. The NH4+:NO3− ratio of 75:25 and NH4+–N as the sole N source significantly increased the soluble sugars in stems and roots, starch in leaves, stems and roots, soluble protein in leaves and stems, and soluble phenols in stems and roots. Additionally, the NH4+:NO3− ratio of 75:25 increased plant height, leaf number, root soluble protein, and leaf soluble phenol contents. In conclusion, regarding the physiological aspects of pecan growth, pecans are more inclined to use NH4+–N. Considering that the NH4+–N as the only N source may lead to nutrient imbalance or even toxicity, the NH4+:NO3− ratio of 75:25 was most favorable for the growth and development of pecan seedlings.


2021 ◽  
Author(s):  
Tiina Savolainen ◽  
Minna-Maarit Kytöviita

Abstract Purpose The ecological importance of arbuscular mycorrhizal fungi (AMF) in plant acquisition of inorganic and organic sources of nitrogen (N) is not clear. To improve understanding of the plant N nutrition ecology, we tested the effect of intraspecific competition and AMF in plant N source use in growth and N acquisition. Methods Solidago virgaurea was grown in microcosms in a fully factorial experiment under greenhouse conditions. The factors tested were intraspecific competition between seedlings and adult plants (yes, no), N source (NH4, glycine) and AMF (inoculated with Glomus hoi, not inoculated). Results When grown separately, non-mycorrhizal seedling growth was highest when grown with ammonium, but non-mycorrhizal adults grew best with glycine as the sole N source. Mycorrhizal symbiosis with Glomus hoi evened out this initial niche partitioning in terms of differences in N source use and all mycorrhizal plants grew best with ammonium. Competition shaped plant benefit from mycorrhizal symbiosis depending on the N source. Competition reduced mycorrhizal growth benefit in glycine-grown seedlings, but not in adults. Plant performance did not show uniform relationship with δ15N, but δ15N was affected by life stage, competition and mycorrhiza. Conclusions Plant competition and AMF shape plant N source use. Plant and AMF benefit of the symbiosis depend on the N source.


2021 ◽  
Vol 7 (12) ◽  
pp. 1040
Author(s):  
Sofia Dimou ◽  
Xenia Georgiou ◽  
Eleana Sarantidi ◽  
George Diallinas ◽  
Athanasios K. Anagnostopoulos

Prof. Peñalva and co-workers provided evidence that AN11127 is related by sequence and function to Sec12 [...]


2021 ◽  
Vol 7 (12) ◽  
pp. 1037 ◽  
Author(s):  
Ignacio Bravo-Plaza ◽  
Miguel Hernández-González ◽  
Miguel Á. Peñalva

Contrary to the opinion recently offered by Dimou et al., our previously published biochemical, subcellular and genetic data supported our contention that AN11127 corresponds to the A. nidulans gene encoding Sec12, which is the guanine nucleotide exchange factor (GEF) specific for SAR1. We add here additional bioinformatics evidence that fully disprove the otherwise negative evidence reported by Dimou et al., highlighting the dangers associated with the lax interpretation of genomic data. On the positive side, we establish guidelines for the identification of this key secretory gene in other species of Ascomycota and Basidiomycota, including species of medical and applied interest.


Synlett ◽  
2021 ◽  
Author(s):  
Tharcisse Gatera ◽  
Daijiao Zhuang ◽  
Rulong Yan

AbstractAn eco-friendly protocol to synthesize nitriles from their corresponding aromatic and aliphatic aldehydes in excellent yields has been developed. This is a catalyst-free protocol which employs an aminating reagent (MsONH3OTf) under mild conditions. The hydroxylamine triflic acid salts (MsONH3OTf) acted as the N source for this protocol. Our protocol proved to be easy to perform and presented good functional group tolerance.


New Forests ◽  
2021 ◽  
Author(s):  
Bartosz Adamczyk ◽  
Sylwia Adamczyk ◽  
Veikko Kitunen ◽  
Tuija Hytönen ◽  
Raisa Mäkipää ◽  
...  

AbstractTree seedlings are produced in tree nurseries. However, nursery-grown seedlings often exhibit poor performance after outplanting due to the lack of adaptation to harsh natural conditions. These nursery-grown seedlings do not necessarily possess well-developed ectomycorrhizal symbionts, which help to obtain nutrients and increase resilience in exchange for seedling photoassimilated carbon. To improve the quality of the seedlings in natural conditions, we sowed spruce seeds on growing media with the addition of wood chips, i.e. stemwood chips or polyphenol- and resin acid-rich knotwood chips. Wood chips were chosen because they are common forest side-streams, and their compounds have shown a potential to improve mycorrhization and seedling fitness. Wood chips initially decreased the growth of seedlings. However, this effect levelled off with time and depended on the quality of the wood. Wood chips had no effect on mycorrhization. Further testing of the wood material showed that wood chips seemed to decrease seedling growth via nitrogen (N) immobilisation rather than a direct toxic effect. The phenomenon of N immobilisation on wood chips could be explored further to develop a slow-release N source, aptly reflecting N availability in natural conditions. Slow-release N source based on wood chips could be beneficial both to increase survival in natural conditions and for environment protection.


2021 ◽  
Vol 2083 (2) ◽  
pp. 022092
Author(s):  
Huan Ge ◽  
Tao Zhu ◽  
Shucheng Chang ◽  
Wanli Zhao ◽  
Xue Bai

Abstract In this paper, we describe a channel self-alignment process to produce High-Voltage VDMOSFETs in 4H-SiC. We use polysilicon as a mask for two injection methods, Because the oxidation rate of polysilicon is different from that of silicon carbide, we can generate a certain thickness of silicon oxide flank wall by controlling the oxidation rate and time. Therefore, there will be a certain distance between the N+ source region and the Pbase region, and this distance is the length of the channel. Obviously, no pattern transfer occurs between the two ion implantation processes, so the channel is self-aligned. As long as the thickness of the side wall is controlled accurately, the channel length of sub-micron can be obtained.


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