Accumulation Of Organic Acids Research Articles

Whole-Genome Analysis of Termite-Derived Bacillus velezensis BV-10 and Its Application in King Grass Silage.

Bacillus velezensis (B. velezensis) is a cellulose-degrading strain that has the potential as an additive in fermented feed. B. velezensis BV-10 was isolated and screened from the termite gut. We sequenced the whole genome of this new source of B. velezensis to reveal its potential for use in cellulose degradation. Whole-genome sequencing of B. velezensis BV-10 showed that it has a circular chromosome of 3929792 bp containing 3873 coding genes with a GC content of 45.51% and many genes related to cellulose, hemicellulose, and lignin degradation. King grass silage was inoculated with B. velezensis BV-10 and mixed with other feed additives to assess the effect of B. velezensis BV-10 on the fermentation quality of silage. Six treatment groups were established: the control, B. velezensis BV-10, molasses, cellulase, B. velezensis BV-10 plus molasses, and B. velezensis BV-10 plus cellulase groups. After 30 days of silage-fermentation testing, B. velezensis BV-10 was found to rapidly reduce the silage pH value and significantly reduce the acid-detergent fiber (ADF) content (p < 0.05). The addition of B. velezensis BV-10 plus molasses and cellulase in fermented feed significantly reduced the silage neutral-detergent fiber and ADF content and promoted organic-acid accumulation (p < 0.05). The above results demonstrate that B. velezensis BV-10 promotes the fermentation quality of silage and that this effect is greater when other silage-fermentation additives are included. In conclusion, genes involved in cellulose degradation in B. velezensis BV-10 were identified by whole-genome sequencing and further experiments explored the effects of B. velezensis BV-10 and different feed additives on the fermentation quality of king grass silage, revealing the potential of Bacillus velezensis as a new silage additive.

Microbial corrosion behavior and mechanism of 5A06 aluminum alloy under low dose proton radiation

Low-dose proton radiation is one of the important factors that have a major impact on microorganisms in spacecraft. In this paper, the changes in the life activity characteristics of Penicillium oxalate and its impact on the corrosion behavior and mechanism of 5A06 aluminum alloy under low-dose proton radiation have been reported. The results show that the survival rate of the fungus is only 24.8 % under the low radiation condition, but its growth rate is faster and the content of organic acid produced by the metabolism of the fungus is higher per unit. The fungal attachment area was deeper and corroded more severely. Electrochemical tests have shown that the corrosion rate of aluminum alloy is related to the organic acid content in the metabolic solution, so the accumulation of organic acids is considered the main reason for the sever and faster corrosion of 5A06 aluminum alloy under low radiation.

Dynamic patterns and diversity of organic acids accumulation in strawberry fruits of different germplasms

Dynamic patterns and diversity of organic acids accumulation in strawberry fruits of different germplasms

Screening of microalgae strains for efficient biotransformation of small molecular organic acids from dark fermentation biohydrogen production wastewater

Dark fermentation biohydrogen production is a rapidly advancing and well-established field. However, the accumulation of volatile organic acid (VFAs) byproducts hinder its practical applications. Microalgae have demonstrated the ability to efficiently utilize VFAs while also treating waste gases and other nutrient elements. Integrating microalgae cultivation with dark fermentation is a promising approach. However, low VFAs tolerance and slow VFAs consumption restrict their application. To find suitable wastewater treatment microalgae, this work screened eight microalgae strains from five family. The results demonstrated that Chlamydomonas reinhardtii exhibited significant advantages in VFAs utilization, achieving a maximum removal of 100% for acetate and 52.5% for butyrate. Among the tested microalgae strains, CW15 outperformed in terms of photobioreactor adaptability, VFAs utilization, biomass productivity, and nutrient removal, making it the most promising microalgae for practical applications. This research demonstrates the feasibility of integrating microalgae cultivation with dark fermentation and providing a viable technical solution for integrated-biorefining.

Characterization of color, metabolites and microbial community dynamics of doubanjiang during constant temperature fermentation

This study aimed to elaborate the effect of temperature on doubanjiang fermentation. Two batches of constant-temperature groups were prepared and their physicochemical parameters, color formation, metabolites and microbial community dynamics during fermentation were determined and compared with those of natural temperature fermentation group. The results showed that fermentation at 40 °C could accelerate the accumulation of amino nitrogen, reducing sugar, amino acids, organic acids and various volatile metabolites while it was able to inhibit the growth of conditionally pathogenic bacteria, such as Klebsiella and Salmonella. However, high concentrations of total acids and biogenic amines, protrusive burnt flavor and darker color were observed in constant temperature fermentation, which were unfavorable for doubanjiang quality. Higher fermentation temperature lowered the diversity of bacterial community and favored the growth of Bacillus genus. The correlation between key microbial genera and doubanjiang quality indexes were significantly different among different temperatures. This study would deep our understanding of the roles of temperature ondoubanjiangfermentation.

Increase CO2 recycling of Escherichia coli containing CBB genes by enhancing solubility of multiple expressed proteins from an operon through temperature reduction.

One of the current promising solutions to address problems of CO2 emissions is the development of biological carbon fixation strategies. This strategy leads to higher chemical biosynthetic productivity through improved biological CO2 fixation. In a previous study, we introduced the Calvin-Benson Bassham (CBB) genes of the photosynthetic bacterium Cereibacter sphaeroides into Escherichia coli to develop a strain capable of endogenous CO2 recycling by heterologous expression of the CBB genes. However, the heterologous expression of recombinant proteins in E. coli is often hampered by inclusion bodies (IB), which are protein aggregates. Various factors contribute to IB formation, including host cell metabolism, protein synthesis, transformation machinery, and target protein properties. In this study, we investigated the influence of environmental conditions, particularly culture temperature, on IB formation and CO2 recycling in the CBB strain. As a result, by reducing the culture temperature from 37°C to 30°C, a significant suppression of IB formation was achieved, resulting in a remarkable decrease in CO2 release by approximately 5.76 times. In addition, interestingly, an enhancement in the accumulation of pyruvate by approximately 2.3 times was observed at the same time. These results demonstrate the simultaneous improvements in CO2 recycling and the synthesis of organic acids achieved through temperature control. Based on the findings of this study, we believe that temperature control would be a promising approach to increasing chemical biosynthetic productivity as well as biological CO2 fixation activity in integrated autotrophic biorefinery strategies. IMPORTANCE In a previous study, we successfully engineered Escherichia coli capable of endogenous CO2 recycling through the heterologous expression of the Calvin-Benson Bassham genes. Establishing an efficient gene expression environment for recombinant strains is crucial, on par with the importance of metabolic engineering design. Therefore, the primary objective of this study was to further mitigate greenhouse gas emissions by investigating the effects of culture temperature on the formation of inclusion bodies (IB) and CO2 fixation activity in the engineered bacterial strain. The findings demonstrate that lowering the culture temperature effectively suppresses IB formation, enhances CO2 recycling, and concurrently increases the accumulation of organic acids. This temperature control approach, without adding or modifying compounds, is both convenient and efficient for enhancing CO2 recycling. As such, additional optimization of various environmental parameters holds promise for further enhancing the performance of recombinant strains efficiently.

Effects of Magnesium Imbalance on Root Growth and Nutrient Absorption in Different Genotypes of Vegetable Crops.

Magnesium (Mg) plays a crucial role in crop growth, but how Mg supply level affects root growth and nutrient absorption in vegetable crops with different genotypes has not been sufficiently investigated. In this study, the responses of tomato (Solanum lycopersicum L.) and cucumber (Cucumis sativus L.) crops to different levels of Mg supply were explored. Four levels of Mg treatment (i.e., 0.2, 1.0, 2.0, 3.0 mmol/L) were applied under hydroponic conditions, denoted as Mg0.2, Mg1, Mg2, and Mg3, respectively. The results showed that with increasing Mg levels, the plant biomass, root growth, and nutrient accumulation in both vegetable crops all increased until reaching their maximum values under the Mg2 treatment and then decreased. The total biomass per tomato plant of Mg2 treatment was 30.9%, 14.0%, and 14.0% higher than that of Mg0.2, Mg1, and Mg3 treatments, respectively, and greater increases were observed in cucumber plant biomass (by 54.3%, 17.4%, and 19.9%, respectively). Compared with the Mg0.2 treatment, the potassium (K) and calcium (Ca) contents in various plant parts of both crops remarkably decreased under the Mg3 treatment. This change was accompanied by prominently increased Mg contents in various plant parts and para-hydroxybenzoic acid and oxalic acid contents in root exudates. Irrespective of Mg level, plant biomass, root growth, nutrient accumulation, and root exudation of organic acids were all higher in tomato plants than in cucumber plants. Our findings indicate that excessive Mg supply promotes the roots to exude phenolic acids and hinders the plants from absorbing K and Ca in different genotypes of vegetable crops despite no effect on Mg absorption. A nutritional deficiency of Mg stimulates root exudation of organic acids and increases the types of exuded organic acids, which could facilitate plant adaption to Mg stress. In terms of root growth and nutrient absorption, tomato plants outperform cucumber plants under low and medium Mg levels, but the latter crop is more tolerant to Mg excess.

Integrated Transcriptome and Metabolome Analysis of Salinity Tolerance in Response to Foliar Application of β-Alanine in Cotton Seedlings.

Salinity is amongst the serious abiotic stresses cotton plants face, impairing crop productivity. Foliar application of β-alanine is employed to improve salt tolerance in various crops, but the exact mechanism behind it is not yet completely understood. An advanced line SDS-01 of upland cotton Gossypium hirsutum L. was utilized to determine its salt tolerance. Foliar treatment with the β-alanine solution at different concentrations was applied to the seedlings stressed with 0.8% NaCl solution. On the 10th day of treatment, samples were collected for transcriptome and metabolome analyses. β-alanine solution at a concentration of 25 mM was found to be the best treatment with the lowest mortality rate and highest plant height and above-ground biomass under salt stress. Both differentially expressed genes and accumulated metabolites analyses showed improved tolerance of treated seedlings. The photosynthetic efficiency improved in seedlings due to higher expression of photosynthesis-antenna proteins and activation of hormones signal transduction after treatment with β-alanine. Highly expressed transcription factors observed were MYB, HD-ZIP, ARF, MYC, EREB, DELLA, ABF, H2A, H4, WRKY, and HK involved in the positive regulation of salinity tolerance in β-alanine-treated seedlings. Furthermore, compared to the control, the high accumulation of polyamines, coumarins, organic acids, and phenolic compounds in the β-alanine-treated seedlings helped regulate cellular antioxidant (glutathione and L-Cysteine) production. Hence, to improve salt tolerance and productivity in cotton, foliar application of β-alanine at the seedling stage can be a valuable management practice.

Elevated CO2 reduced antimony toxicity in wheat plants by improving photosynthesis, soil microbial content, minerals, and redox status.

Antimony (Sb), a common rare heavy metal, is naturally present in soils at low concentrations. However, it is increasingly used in industrial applications, which in turn, leads to an increased release into the environment, exerting a detrimental impact on plant growth. Thus, it is important to study Sb effects on plants under the current and future CO2 (eCO2). To this end, high Sb concentrations (1500 mg/kg soil) effects under ambient (420 ppm) and eCO2 (710 ppm) on wheat growth, physiology (photosynthesis reactions) and biochemistry (minerals contents, redox state), were studied and soil microbial were evaluated. Our results showed that Sb uptake significantly decreased wheat growth by 42%. This reduction could be explained by the inhibition in photosynthesis rate, Rubisco activity, and photosynthetic pigments (Cha and Chb), by 35%, 44%, and 51%, respectively. Sb significantly reduced total bacterial and fungal count and increased phenolic and organic acids levels in the soil to decrease Sb uptake. Moreover, it induced oxidative markers, as indicated by the increased levels of H2O2 and MDA (1.96 and 2.8-fold compared to the control condition, respectively). To reduce this damage, antioxidant capacity (TAC), CAT, POX, and SOD enzymes activity were increased by 1.61, 2.2, 2.87, and 1.86-fold, respectively. In contrast, eCO2 mitigated growth inhibition in Sb-treated wheat. eCO2 and Sb coapplication mitigated the Sb harmful effect on growth by reducing Sb uptake and improving photosynthesis and Rubisco enzyme activity by 0.58, 1.57, and 1.4-fold compared to the corresponding Sb treatments, respectively. To reduce Sb uptake and improve mineral availability for plants, a high accumulation of phenolics level and organic acids in the soil was observed. eCO2 reduces Sb-induced oxidative damage by improving redox status. In conclusion, our study has provided valuable insights into the physiological and biochemical bases underlie the Sb-stress mitigating of eCO2 conditions. Furthermore, this is important step to define strategies to prevent its adverse effects of Sb on plants in the future.

Acid tolerance of lactate-utilizing bacteria of the order Bacteroidales contributes to prevention of ruminal acidosis in goats adapted to a high-concentrate diet.

The rapid accumulation of organic acids, particularly lactate, has been suggested as the main cause of ruminal acidosis (RA) for ruminants fed high-concentrate diets. Previous research has shown that a gradual shift from low-to high-concentrate diets within 4 to 5 weeks effectively reduces the risk for RA. However, the mechanisms remain unknown. In this study, 20 goats were randomly allocated into four groups (n=5) and fed with a diet containing a weekly increasing concentrate portion of 20%, 40%, 60%, and 80% over 28d. At d 7, 14, 21, and 28, one group (named C20, C40, C60, and C80 according to the last concentrate level that they received) was killed and the ruminal microbiome was collected. Ruminal acidosis was not detected in any of the goats during the experiment. Nonetheless, ruminal pH dropped sharply from 6.2 to 5.7 (P<0.05) when dietary concentrate increased from 40% to 60%. A combined metagenome and metatranscriptome sequencing approach identified that this was linked to a sharp decrease in the abundance and expression of genes encoding nicotinamide adenine dinucleotide (NAD)-dependent lactate dehydrogenase (nLDH), catalyzing the enzymatic conversion of pyruvate to lactate (P<0.01), whereas the expression of two genes encoding NAD-independent lactate dehydrogenase (iLDH), catalyzing lactate oxidation to pyruvate, showed no significant concomitant change. Abundance and expression alterations for nLDH- and iLDH-encoding genes were attributable to bacteria from Clostridiales and Bacteroidales, respectively. By analyzing the gene profiles of 9 metagenome bins (MAG) with nLDH-encoding genes and 5 MAG with iLDH-encoding genes, we identified primary and secondary active transporters as being the major types of sugar transporter for lactate-producing bacteria (LPB) and lactate-utilizing bacteria (LUB), respectively. Furthermore, more adenosine triphosphate was required for the phosphorylation of sugars to initiate their catabolic pathways in LPB compared to LUB. Thus, the low dependence of sugar transport systems and catabolic pathways on primary energy sources supports the acid tolerance of LUB from Bacteroidales. It favors ruminal lactate utilization during the adaptation of goats to a high-concentrate diet. This finding has valuable implications for the development of measures to prevent RA.

Untargeted metabolomics reveals sour jujube kernel benefiting the nutritional value and flavor of Morchella esculenta.

Nucleosides, organic acids, and amino acids separated from Morchella esculenta are well known for their nutritional value and flavor. However, how to increase their content in a better way has been a challenge. In this study, the effect of adding jujube kernel on the active components of M. esculenta was investigated by untargeted metabolomics using UPLC-MS/MS. A total of 1,243 metabolites were identified, of which 262 metabolites (21.078%) were organic acids and derivatives, 245 metabolites (19.71%) were lipids and lipid-like molecules, and 26 metabolites (2.092%) were nucleosides, nucleotides, and analogues. Subsequently, differential metabolites between groups were screened by the orthogonal partial least squares-discriminant analysis model, which showed that 256 metabolites were identified as significantly different for the positive ion model and 149 for the negative ion model. Moreover, significant differential metabolites (VIP > 1, P < 0.05) in annotation of kyoto encyclopedia of genes and genomes pathway were investigated, which showed that ABC transporters were the most commonly observed transporters, followed by pyrimidine metabolism and purine metabolism. The results indicated that the main components of jujube kernel might be conducive to the accumulation of nucleoside organic acids and amino acid metabolites in M. esculenta. These results provide important information for the understanding of more suitable way for cultivation of M. esculenta.

Transcriptome and Metabolome Reveal Sugar and Organic Acid Accumulation in Rosa roxburghii Fruit.

Sugars and organic acids significantly impact fruit sensory quality, but their accumulation patterns and regulatory mechanisms during the development of Rosa roxburghii fruit are still unclear. We utilized transcriptomics and metabolomics to investigate genes related to sugar and organic acid metabolism in Rosa roxburghii. Metabolomics data revealed that sucrose, glucose and fructose were the primary sugars, whereas citric acid and malic acid were the primary organic acids in Rosa roxburghii fruit. We constructed the metabolic pathways of major sugars and organic acids in Rosa roxburghii and identified five key genes involved in sugar and organic acid synthesis. In addition, we identified a module containing 132 transcription factors that was significantly associated with sucrose, citric acid and malic acid. Based on quantitative polymerase chain reaction (qPCR), we identified 13 transcription factors involved in sugar and organic acid metabolism, including the transcription factor RrANL2 and the sucrose synthase gene RrSUS3. Further yeast one-hybrid and dual luciferase assays showed that RrANL2 could bind to the promoter of RrSUS3 to increase its expression. These results provide new insights into the metabolism of sugars and organic acids in Rosa roxburghii fruit.

The interplay between autophagy and chloroplast vesiculation pathways under dark-induced senescence.

In cellular circumstances where carbohydrates are scarce, plants can use alternative substrates for cellular energetic maintenance. In plants, the main protein reserve is present in the chloroplast, which contains most of the total leaf proteins and represents a rich source of nitrogen and amino acids. Autophagy plays a key role in chloroplast breakdown, a well-recognised symptom of both natural and stress-induced plant senescence. Remarkably, an autophagic-independent route of chloroplast degradation associated with chloroplast vesiculation (CV) gene was previously demonstrated. During extended darkness, CV is highly induced in the absence of autophagy, contributing to the early senescence phenotype of atg mutants. To further investigate the role of CV under dark-induced senescence conditions, mutants with low expression of CV (amircv) and double mutants amircv1xatg5 were characterised. Following darkness treatment, no aberrant phenotypes were observed in amircv single mutants; however, amircv1xatg5 double mutants displayed early senescence and altered dismantling of chloroplast and membrane structures under these conditions. Metabolic characterisation revealed that the functional lack of both CV and autophagy leads to higher impairment of amino acid release and differential organic acid accumulation during starvation conditions. The data obtained are discussed in the context of the role of CV and autophagy, both in terms of cellular metabolism and the regulation of chloroplast degradation.

Cultivar differences in the hormonal crosstalk regulating apple fruit development and ripening: Relationship with flavour components and postharvest susceptibility to Penicillium expansum

The hormonal interplay during the on-tree development and ripening of three apple cultivars with known differences in their postharvest ripening patterns was studied, at the biochemical and targeted gene expression level, along with characterizing the changes in main sugars, acids, phenylpropanoids and volatile organic compounds (VOCs). Our findings suggest that in ‘Royal Gala’ and ‘Opal®’ apples, a peak in indole 3-acetic acid (IAA) seems necessary to activate ethylene metabolism, being its intensity proportional to the ethylene production. The interplay between IAA and ethylene appears to be mediated by MdARF5, responsible for activating the expression of MdACS3 and triggering ethylene metabolism. On the other hand, the lack of ethylene production observed in ‘Granny Smith’ apples was likely related to the absence of an IAA peak and possibly caused by the over activation of IAA conjugation mechanisms leading to a greater accumulation of IAA inactive conjugates such as indole-3-acetyl-aspartate (IAAsp). Abscisic acid (ABA) accumulation was only observed in cultivars with the ability to accumulate sucrose and produce ethylene, suggesting a possible crosstalk among those hormones and sucrose in orchestrating apple on-tree ripening. While differences in hormone levels among cultivars led to noticeable differences in some specific VOCs, no evident associations were found between hormone changes and the accumulation or degradation of monosaccharides, organic acids or phenolic compounds during fruit development and ripening. Likewise, no clear relationship was found between the fruit susceptibility to blue mould and hormonal levels yet certain specific biochemical compounds (i.e., procyanidins and sucrose) could be acting as a source of resistance or susceptibility, respectively, to blue mould development. Overall, understanding the cultivar specific hormonal regulation of apple on-tree ripening provides valuable insights to optimize fruit quality at the time of harvest as well as to develop strategies for improved postharvest management.

Differential Aluminum tolerance in Arabidopsis thaliana ecotypes is seemingly related to metabolite changes

Plants are negatively affected by aluminum (Al) in acidic soils (pH ≤ 5.0), which impairs root growth and ultimately plant yield. Organic acids are closely related to Al neutralization improving the metal tolerance with an expansive metabolic cost. Here, we investigated phenotypic, metabolic, and genetic responses of three Arabidopsis thaliana ecotypes, Columbia (Col-0), Wassilewskija (Ws) and Landsberg erecta (Ler) in response to Al. By comparing the respective control plants with Al-exposed plants, the ecotypes Col-0 and Ws displayed stronger reductions in root growth and reproductive yield than Ler. All ecotypes presented high expression of ALMT1, an Al-resistance associated gene. Further analyses revealed a large accumulation of diverse amino acids, carbohydrates and organic acids following Al stress in both shoot and root tissues of Col-0 and Ws plants, but not in Ler. Altogether, our results suggest that a higher capacity for using and translocating reduced carbon molecules seems crucial to overcoming Al stress in the Ler ecotype. In addition, lower expenses in carbon molecules might be linked to a higher capacity to deal with Al stress, supporting a tight relationship between primary metabolism and Al stress responses. Finally, novel insights on the influence of Al over plant growth and primary metabolism in both shoots and roots are described.

The Interplay of Sulfur and Selenium Enabling Variations in Micronutrient Accumulation in Red Spinach.

Aside from its importance in human and animal health, low levels of foliar-applied selenate (SeO4) can be advantageous in the presence of sulfur (S), contributing to improved growth, nutrient uptake, and crop quality. A hydroponic experiment in a growth chamber explored the interactive influence of Se and S on micronutrients and several quality indices, such as soluble sugars, organic acids, and total protein concentrations in spinach (Spinacia oleracea L.). Three levels of S (deprivation, adequate, and excessive) with varying quantities of Se (deficient, moderate, and higher) were examined in combination. Under S starvation and along with S nourishment in plant parts, Se treatments were found to cause noticeable variations in plant biomass and the concentrations of the examined elements and other quality parameters. Both Se levels promoted S accumulation in S-treated plants. Although the Se treatment had the opposite effect in shoots, it had a favorable impact on minerals (apart from Mn) in roots grown under S-limiting conditions. The S and Se relationship highlighted beneficial and/or synergistic effects for Mn and Fe in edible spinach portions. Reducing sugars were synergistically boosted by adequate S and moderate Se levels in roots, while in shoots, they were accumulated under moderate-or-higher Se and excessive S. Furthermore, the concentration of the quantified organic acids under S-deficient conditions was aided by various Se levels. In roots, moderate Se under high S application enhanced both malic acid and citric acid, while in the edible parts, higher Se under both adequate and elevated S levels were found to be advantageous in malic acid accumulation. Moreover, by elevating S levels in plant tissues, total protein concentration increased, whereas both moderate and high Se levels (Se1 and Se2) did not alter total protein accumulation in high S-applied roots and shoots. Our findings show that the high S and medium Se dose together benefit nutrient uptake; additionally, their combinations support soluble sugars and organic acids accumulation, contributing ultimately to the nutritional quality of spinach plants. Moreover, consuming 100 g of fresh red spinach shoot enriched with different Se and S levels can contribute to humans' daily micronutrients intake.

Transcriptome data-based identification and expression profiling of genes potentially associated with malic acid accumulation in plum (Prunus salicina Lindl.)

Chinese plum (Prunus salicina Lindl.) is an important commercially produced stone fruit that accumulates high amounts of organic acids with numerous health benefits. Organic acids are key components to determine the flavor of any fruit. Here, to identify the potential genes involved in organic acids accumulation in plum, the metabolomic and transcriptomic analysis of plum fruits were performed at four developmental stages (i.e., fruitlet, green, veraison, and mature). The results suggest that malic acid was predominant among the eight organic acids analyzed. RNA-Seq analysis revealed a total of 26,547 unigenes, of which 7,584 representing 28.56% differentially expressed genes (DEGs) were identified. In addition, 11 enzyme coding genes, 21 transporter genes and 5 MYB transcription factor genes involved in malic acid accumulation were identified. Our combined transcriptomic and targeted metabolomic analyses provides new comprehensive insights into understanding the genetic control of fruit acidity in plum which will be useful for future breeding.

Propionic acidaemia crisis: a specific DWI finding—case report

BackgroundPropionic acidaemia is among the rarest metabolic disorders described in the literatures. It has resulted from an inborn error in the catabolism of amino acids with an accumulation of organic acids as a consequence of this error. This illness was especially manifested and discovered in early postnatal life with other forms seen later in the childhood period.It has different clinical presentations with poor feeding, hypotonia, and lethargy described in the early neonatal period, while mental retardation, global developmental delay, and seizures are seen in childhood.Case presentationWe present a case of a 4-month-old child already diagnosed in his early neonatal period with propionic acidaemia currently presented with propionic acidaemic crisis in the form of frequent attack of seizures and severe hyperammonemia with unique DWI features which shows bilateral symmetrical restricted diffusion in the subcortical and subinsular white matter that are specific to propionic acidaemia crisis and does not relate to any vascular territory.ConclusionPropionic acidaemia is one of the rarest metabolic disorders reported in both early neonatal life and the childhood period. Understanding the clinical presentation and MRI findings with specific DWI changes reported in this case assists the health care provider in making the appropriate clinical management and metabolic screening decisions. This case with these rare and specific DWI changes seems to be unique to the propionic acidaemia crisis which reinforces MRI findings and changes mentioned previously in the literatures.

Exploring the correlation of metabolites changes and microbial succession in solid-state fermentation of Sichuan Sun-dried vinegar

BackgroundThe traditional Sichuan Sun-dried vinegar (SSV) with unique flavor and taste is believed to be generated by the solid-state fermentation craft. However, how microorganisms and their metabolites change along with fermentation has not yet been explored.ResultsIn this study, our results demonstrated that the middle and late stages of SSV fermentation were the periods showing the largest accumulation of organic acids and amino acids. Furthermore, in the bacterial community, the highest average relative abundance was Lactobacillus (ranging from 37.55 to 92.50%) in all fermentation stages, while Acetobacters ranked second position (ranging from 20.15 to 0.55%). The number of culturable lactic acid bacteria is also increased during fermentation process (ranging from 3.93 to 8.31 CFU/g). In fungal community, Alternaria (29.42%), Issatchenkia (37.56%) and Zygosaccharomyces (69.24%) were most abundant in different fermentation stages, respectively. Interestingly, Zygosaccharomyces, Schwanniomyces and Issatchenkia were first noticed as the dominant yeast genera in vinegar fermentation process. Additionally, spearman correlation coefficients exhibited that Lactobacillus, Zygosaccharomyces and Schwanniomyces were significant correlation with most metabolites during the fermentation, implying that these microorganisms might make a significant contribution to the flavor formation of SSV.ConclusionThe unique flavor of SSV is mainly produced by the core microorganisms (Lactobacillus, Zygosaccharomyces and Schwanniomyces) during fermentation. This study will provide detailed information related to the structure of microorganism and correlation between changes in metabolites and microbial succession in SSV. And it will be very helpful for proposing a potential approach to monitor the traditional fermentation process.

Transcriptome analysis of sugar and acid metabolism in young tomato fruits under high temperature and nitrogen fertilizer influence.

Environmental temperature and nitrogen (N) fertilizer are two important factors affecting the sugar and organic acid content of tomato fruit. N is an essential nutrient element for plant growth and development, and plays a key role in regulating plant growth, fruit quality and stress response. However, the comparative effect of different N fertilizer levels on the accumulation of soluble sugar and organic acid in tomato young fruit under high temperature stress and its mechanism are still unknown. Three N fertilizer levels (N1, N2, N3) combined with two temperatures (28/18°C, CK; 35/25°C, HT) were used to study the effects of N fertilizer, HT and their interaction on the soluble sugar and organic acid components, content, metabolic enzyme activity and the expression level of key genes in tomato young fruit, revealing how N fertilizer affects the sugar and organic acid metabolism of tomato young fruit under HT at physiological and molecular levels. The content of soluble sugar and organic acid in tomato young fruit under HT exposure was increased by appropriate N fertilizer (N1) treatment, which was due to the accumulation of glucose, fructose, citric acid and malic acid. High N (N3) and HT exposure had a negative impact on soluble sugar and reduce sugar accumulation. Further studies showed that due to the up-regulation of the expression of sucrose metabolizing enzyme genes (CWINV2, HK2, SPS, PK) and sucrose transporter (SUT1, SUT4, SWEETs) in tomato, N fertilizer increased the accumulation of soluble sugar by improving the sucrose metabolism, absorption intensity and sucrose transport of fruit under HT exposure. Due to the increase of PEPC gene expression, N fertilizer increased the accumulation of citric acid and malic acid by improving the TCA cycle of fruit under HT exposure. Nitrogen fertilizer can improve the heat tolerance of tomato young fruits by improving sugar metabolism under HT exposure. The results can provide theoretical support for the correct application of N fertilizer to improve the quality of tomato fruit under HT exposure.