Amounts Of Organic Acids Research Articles

Crop diversity for mixed first and second generation ethanol production

ABSTRACTThermohydrolysis at low temperatures achieves lower conversion compared to high temperatures. However, the process consumes less energy. We tried to make this pretreatment process more efficient by adding triticale grist to the fermentation and use the positive effect of the protein content and the increased ethanol concentration. The concept is made for rebuild of grain distilleries and reuse of the large equipment. The concept was evaluated for several crops with an attempt to crop diversity in the fields. This work presents thermohydrolysis (155°C, 45 min) with subsequent steam explosion combined with an enzymatic hydrolysis and the addition of triticale grist in the fermentation process. All substrates achieved improved cellulose hydrolysis, except for the silages. Over 90% of the cellulose in hemp straw and Jerusalem artichoke stalks was converted to glucose. Analysis for inhibitors showed high amounts of organic acids solely in Jerusalem artichoke mashes, corn and wild plant silage. The chosen conditions are suitable for a great variety of crops, also as intercrop scenario. However, silages need pH adjustment. The high loads of organic acids clearly suppress amylase activity, but cellulase activity seems to be unaffected. The switch to mixed first and second generation ethanol production in distilleries is possible.

Classification and the developmental regularity of organic-associated pores (OAP) through a comparative study of marine, transitional, and terrestrial shales in China

Organic-rich shales, deposited in marine, terrestrial, and marine-terrestrial transitional (hereinafter referred to as transitional) sedimentary environments, were selected to evaluate the nature of organic-associated pores (OAP) and their developmental regularity using broad ion beam milling and scanning electronic microscopy (BIB-SEM).At least seven organic matter (OM) components (alginite, exinite, vitrinite, inertinite, amorphinite otherwise solid bitumen, bitumen, and bioclast) were identified under BIB-SEM based on their in-situ morphology in shale matrix. Besides, OAP were classified into four subtypes based on their differences in genetic mechanism, i.e., hydrocarbon-bubble pores (HBP), hydrocarbon-dissolution pores (HDP), hydrocarbon-shrinkage cracks (HSC), and bioclast-skeleton pores (BSP). HBP formed within OM are generated by the gas-exsolution from the OM surface under the gas-expansion force at the gas window stage, and thereby are widely developed in highly matured marine shales that are rich in structure-alterable liptinite (alginite, amorphinite, exinite, solid bitumen). HDP are essentially the secondary pores in minerals formed by the corrosion of organic-acids before or at the oil window stage and therefore are mostly developed in immature terrestrial shales containing certain amount of organic acids. HSC formed at the OM periphery are caused by the volumetric contraction of OM in case that they cannot generate the HBP within them, and thereby are commonly found in transitional shales which are rich in structure-stable huminite. BSP are the inherited internal structure pores of some bioclasts (planktonic algae or plant tissues), and they occupy only a small part of the total OAP in all of the three kinds of sedimentary facies shales.

Effect of Fermentation Temperature on the Volatile Composition of Kimchi.

This study was conducted to evaluate the effect of fermentation temperature on the volatile composition in Kimchi. Kimchi was fermented at 2 temperature conditions (4 and 20 °C). Volatile compounds of Kimchi samples were analyzed during the fermentation periods using the dynamic headspace gas chromatography-mass spectrometry method. The optimum ripening time for the Kimchi fermented at 4 °C was 35 d, and that of 20 °C was 2 d. The pH at the optimum ripening time was 4.97 and 4.41, and the titratable acidity was 0.59% and 0.76% for the Kimchi fermented at 4 and 20 °C, respectively. Forty different types of volatile compounds, including alcohol, aldehyde, ester, and sulfur compounds, were identified. The Kimchi fermented at 20 °C produced greater amounts of volatile compounds than that at 4 °C. The amounts of most volatiles increased as the fermentation time increased, but those of aldehydes decreased rapidly during both 4 and 20 °C fermentation. Organic acids, ester, and nitriles were detected only in Kimchi fermented at 20 °C. The amounts of dimethyl disulfide, methyl-2-propenyl disulfide, and di-2-propenyl disulfide produced from the Kimchi fermented at 20 °C were more than 2-times of those at 4 °C. Therefore, it is concluded that the strong pungent odor of Kimchi fermented at 20° C is probably due to the high amount of organic acids (low pH) and sulfur compounds (dimethyl disulfide, methyl-2-propenyl disulfide, and di-2-propenyl disulfide) between the 2 Kimchi.

Effect of lactic acid bacteria on microbial safety of angelica keiskei juice

AbstractThis study investigated the inhibitory activities of lactic acid bacteria (LAB) against Bacillus cereus in the Angelica keiskei juice. After pasteurization, yeasts, molds, Pseudomonas, and coliform bacteria can be inactivated effectively, but population of Bacillus cereus did not show significantly decreased. To inhibit the growth of B. cereus, Lactobacillus plantarum, casei, and acidophilus were applied to ferment the pasteurized Angelica keiskei juice. Through 48 hr fermentation, the populations of LABs increased 4.12, 3.64, and 3.59 log10 CFU/ml, respectively. The population of B. cereus increased 1.30, 1.92, and 2.04 log10 CFU/ml, respectively, but in the control group, it increased 3.23 log10 CFU/ml. Cereulide (a B. cereus emetic toxin) was identified in the control group, 36 as well as 48 hr of L. casei, and 48 hr of L. acidophilus fermented juice, but not in L. plantarum. The amount of the cereulide biosynthesis genes expression of B. cereus in Lactobacillus fermented juice was significant lower than that in the control group. These findings indicate that Lactobacillus can inhibit the growth of B. cereus in Angelica keiskei juice, and L. plantarum shows the best effect.Practical applicationsFresh Angelica keiskei juice is considered to be a healthy beverage, attributing to its numerous beneficial effects recently. However, microbial risk is always existent due to fresh Angelica keiskei juice is easy to be contaminated by some soil and heat resistant microorganisms, including B. cereus, which is unable to be inactivated by pasteurization. LAB are used in Angelica keiskei juice to inhibit the growth of B. cereus since they can generate a large amount of organic acids and bacteriocins. Hence, Angelica keiskei juice can be developed as a healthily fermented juice.

Bioactive compounds and antioxidant potential in tomato pastes as affected by hot and cold break process.

The effects of hot and cold break industrial tomato paste production steps on phenolic compounds, carotenoids, organic acids, hydroxy methyl furfural (HMF) and other quality parameters of tomato pastes were investigated in this study. Phenolic compounds, carotenoids, organic acids, and HMF analyses were performed with LC-DAD-ESI-MS/MS and LC-DAD-RID was used for the sugar analyses. Furthermore, the antioxidant capacities of tomato pastes were assessed via the DPPH and ABTS methods. The increase of phenol acids at the processing steps of cold break production method was higher than the hot break production method. According to PCA analyses, phenolic acids characterized cold break tomato pastes while hot break tomato pastes were characterized by flavanols and flavanones. The total amount of organic acids decreased with processing and the loss of organic acids was lower in cold break pastes. Heating and evaporation were determined as the most important processing steps in which the amount of different quality parameters change.

Effects of Pyrene on Low Molecule Weight Organic Compounds in the Root Exudates of Five Species of Festuca

Phytoremediation is an important measure to remove organic pollutants from contaminated soil, and the root secretion of plant is considered to be closely related to the mechanisms of phytoremediation of organic pollutants. It is in favor of revealing the mechanisms of remediation by studying the characteristics of root exudates of plants with phytoremediation potential under the stress of pollutants. In the present research, pyrene and five species of Festuca which have been testified to be tolerant to pyrene stress were selected as studied objects. A soil-cultivating experiment with rhizobag technique was conducted to investigate the effects of pyrene on low molecule weight organic compounds in the root exudates of plant species under five concentration levels of pyrene (10.19, 20.32, 40.36, 79.94,and 160.68 mg·kg-1,denoted by C1, C2, C3, C4 and C5,respectively) on day 30, 40, 50, 60 and 70 of experiments. The results showed that the presence of vegetation significantly enhanced the dissipation of pyrene in the soil environment. This effect was especially marked with Festuca arundinacea, followed by those with Festuca mazzetiana, Festuca pubiglumis, and Festuca longiglumis, and that with Festuca stapfii was the lowest. During the whole experiments, the amounts of soluble sugar excreted by the five species of Festuca tested in root exudates were promoted with pyrene stress, then fluctuated with a stable trend along with the increase of stress concentration or the extension of stress period, which appeared to rise appreciably at relative low pyrene spiked (C1-C3) or earlier stress stage (30-40 d) and reduce at relative high pyrene spiked level (C3-C5) or later stress stage (40-70 d), and the highest amount of soluble sugars in root exudates occurred on day 50 of experiments with 40.36 mg·kg-1 pyrene treatment. The greater the phytoremediation potential of the plant species tested, the more obvious this trend wads. Compared with the control treatment (CK), pyrene stress promoted the root system of all five species of Festuca tested to release more low molecular weight organic acids, the stronger the restoration potential of plant species, the higher the concentration of pyrene stress under which the amount of organic acids in root exudates was increased to the peak value. Among the five species of Festuca tested, oxlic acid, acetic acid, lactic acid and malic acid were the main components of organic acids in root exudates, with a percentage of greater than 98.15% in all pyrene stress treatments, but there were traces of fumaric acid in the roots secretion of plant species with the stronger restoration potential. Data also indicated that 19 types of amino acids were found in root exudates of Festuca and the composition of amino acids in root exudates of Festuca was stable under all pyrene stress treatments, but the amino acid amount was different in root exudates under pyrene stress. The amount of all amino acids in those root exudates increased with increasing pyrene concentration, especially, the amount of threonine, serine, glycine, and alanine increased significantly among the 19 types of amino acids and the differences were significant among different treatments with different pyrene concentrations (P<0.05). However, proline, hydroxy proline and aspartic acid were always released in the form of functional group as a response to the pyrene stress, their contents soared quickly with the increase of stress concentration in soils, and the difference was significant among different treatments with different pyrene concentrations (P<0.05); the more the components of functional group participated in stress response, the stronger the restoration potential of plant species. These results indicated secretion characteristics of soluble sugar, low molecular weight organic acids and amino acids in the root system were closely related to their phytoremediation potential under the pyrene stress, the greater the phytoremediation potential, the more the amount of these low molecular weight secretions and the more complex these components, and the stronger the adaptability to polluted environment and the physiological plasticity to adapt to these contaminants.

QUALITATIVE COMPOSITION AND ORGANI C ACIDS CONTENT IN THE ABOVEGROUN D PART OF PLANTS FRO M FAMILIES LAMIACEAE, ASTERACEAE, APIACEAE AND CHENOPODIACEAE

&lt;p&gt;Background. Organic acids are the compounds of aliphatic or aromatic orders, which are widespread in&lt;br /&gt;flora and have a wide range of biological activity. We studied the qualitative composition and quantitative contents&lt;br /&gt;of organic acids in the aboveground part of some unofficial medicinal plants from families Lamiaceae, Asteraceae,&lt;br /&gt;Apiaceae and Chenopodiaceae is relevant.&lt;br /&gt;Objective. The objects of the research are the aboveground part of unofficial medicinal plants from families&lt;br /&gt;Lamiaceae, Asteraceae, Apiaceae and Chenopodiaceae.&lt;br /&gt;Methods. Identification of organic acids was performed by means of thin-layer and paper chromatography,&lt;br /&gt;their content was determined by means of gas chromatography, the quantitative amount of organic acids was&lt;br /&gt;defined by titrimetric analysis.&lt;br /&gt;Results. In the studied raw plants the quality of organic acids and their total contents were determined (in&lt;br /&gt;terms of malic acid). It is established that the maximum content of organic acids is accumulated in the grass&lt;br /&gt;Hyssopus officinalis L. (Lamiaceae), and the minimal is in the leaves of Chrysánthemum xhortorum L. variety Apro&lt;br /&gt;(Asteraceae). In all studied raw plants the dominance of aliphatic acids (citric, malic, oxalic and malonic) was&lt;br /&gt;determined by means of gas chromatography. Benzoic is predominant among the aromatic acids.&lt;br /&gt;Conclusions. In the studied raw plants the quality of organic acids and their total content were determined.&lt;br /&gt;The following results can be used in developing the methods of quality control of the studied raw plants and&lt;br /&gt;during the study of new bioactive substances.&lt;br /&gt;KEY WORDS: organic acids, Lamiaceae, Asteraceae, Apiaceae, Сhenopodiaceae, grass, leaves, thinlayer&lt;br /&gt;chromatography, gas chromatography, paper chromatography.&lt;/p&gt;

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

Extensive Literature Search on the ‘Effects of Copper intake levels in the gut microbiota profile of target animals, in particular piglets’

Quality Control of Gamma Irradiated Dwarf Mallow (Malva neglecta Wallr.) Based on Color, Organic Acids, Total Phenolics and Antioxidant Parameters.

This study addresses the effects of gamma irradiation (1, 5 and 8 kGy) on color, organic acids, total phenolics, total flavonoids, and antioxidant activity of dwarf mallow (Malva neglecta Wallr.). Organic acids were analyzed by ultra fast liquid chromatography (UFLC) coupled to a photodiode array (PDA) detector. Total phenolics and flavonoids were measured by the Folin-Ciocalteu and aluminium chloride colorimetric methods, respectively. The antioxidant activity was evaluated based on the DPPH• scavenging activity, reducing power, β-carotene bleaching inhibition and thiobarbituric acid reactive substances (TBARS) formation inhibition. Analyses were performed in the non-irradiated and irradiated plant material, as well as in decoctions obtained from the same samples. The total amounts of organic acids and phenolics recorded in decocted extracts were always higher than those found in the plant material or hydromethanolic extracts, respectively. The DPPH• scavenging activity and reducing power were also higher in decocted extracts. The assayed irradiation doses affected differently the organic acids profile. The levels of total phenolics and flavonoids were lower in the hydromethanolic extracts prepared from samples irradiated at 1 kGy (dose that induced color changes) and in decocted extracts prepared from those irradiated at 8 kGy. The last samples also showed a lower antioxidant activity. In turn, irradiation at 5 kGy favored the amounts of total phenolics and flavonoids. Overall, this study contributes to the understanding of the effects of irradiation in indicators of dwarf mallow quality, and highlighted the decoctions for its antioxidant properties.

Identification and functional analysis of the L-ascorbate-specific enzyme II complex of the phosphotransferase system in Streptococcus mutans.

BackgroundStreptococcus mutans is the primary etiological agent of human dental caries. It can metabolize a wide variety of carbohydrates and produce large amounts of organic acids that cause enamel demineralization. Phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS) plays an important role in carbohydrates uptake of S. mutans. The ptxA and ptxB genes in S. mutans encode putative enzyme IIA and enzyme IIB of the L-ascorbate-specific PTS. The aim of this study was to analyze the function of these proteins and understand the transcriptional regulatory mechanism.ResultsptxA−, ptxB−, as well as ptxA−, ptxB− double-deletion mutants all had more extended lag phase and lower growth yield than wild-type strain UA159 when grown in the medium using L-ascorbate as the sole carbon source. Acid production and acid killing assays showed that the absence of the ptxA and ptxB genes resulted in a reduction in the capacity for acidogenesis, and all three mutant strains did not survive an acid shock. According to biofilm and extracellular polysaccharides (EPS) formation analysis, all the mutant strains formed much less prolific biofilms with small amounts of EPS than wild-type UA159 when using L-ascorbate as the sole carbon source. Moreover, PCR analysis and quantitative real-time PCR revealed that sgaT, ptxA, ptxB, SMU.273, SMU.274 and SMU.275 appear to be parts of the same operon. The transcription levels of these genes were all elevated in the presence of L-ascorbate, and the expression of ptxA gene decreased significantly once ptxB gene was knockout.ConclusionsThe ptxA and ptxB genes are involved in the growth, aciduricity, acidogenesis, and formation of biofilms and EPS of S. mutans when L-ascorbate is the sole carbon source. In addition, the expression of ptxA is regulated by ptxB. ptxA, ptxB, and the upstream gene sgaT, the downstream genes SMU.273, SMU.274 and SMU.275 appear to be parts of the same operon, and L-ascorbate is a potential inducer of the operon.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0668-9) contains supplementary material, which is available to authorized users.

A method for determination of the acidifying value of organic acids used in pigs diets in the acid binding capacity at pH 4 (ABC-4) system

The objective of this study was to measure the ABC-4 values for organic acids using their compensating effects on various feedstuffs ABC-4 values and to propose a model predicting organic acids ABC-4 values using acid characteristics such as pKa and molecular weight. Measurements of the amount of HCl required to lower the pH of 1kg of sample to pH 4.0 were determined as the ABC-4 on a 0.5g sample of feed ingredient (wheat, soybean meal and dicalcium phosphate). A substitution of HCl 0.1N by an organic acid: dl-2-hydroxy-4-methylthiobutyric acid (HMTBA), formic acid, butyric acid or malic acid was realized with three different proportions (11.7, 23.5 or 35.2 mEq H+). The amount of HCl needed to lower the pH at 4 was recorded and the new ABC’-4 determined. The acidifying effect of organic acids was calculated for wheat and soybean as the difference between ABC’-4 and ABC-4. Results indicated that ABC-4 determined for wheat was lower than ABC-4 of soybean meal and dicalcium phosphate. A mixture of these ingredients resulted in the addition of their ABC-4 values proportionally to their level of inclusion. The ΔABC-4 obtained for organic acids showed a significant difference between these acids with HMTBA and formic acid having the highest acidifying effect on equivalent dose base. The slopes obtained from the linear regression of ΔABC-4 in function of the amount of organic acid added, were not significantly different between wheat and soybean meal for all selected organic acids. Based on these observations and knowing that purity, pKa and molar mass of the acid itself can affect the amount of H+ released, an equation was proposed to predict the ABC-4 of organic acids. HMTBA is as acidifying as formic acid on equimolar basis. Inclusion of 1kg of HMTBA per ton of diet would supply −4876 mEq H+. This study allowed feed formulation using ABC-4 of ingredients and acids for optimal weaned pig performance.

흑마늘의 첨가량과 초기 알코올 농도를 달리한 발효 식초의 품질특성

The quality characteristics of black garlic vinegar produced by acetic acid fermentation were analyzed over a 25 day period. Black garlic vinegar was produced using black garlic 3, 6, 9 and 12 folds with water, and initial alcohol concentrations of 6~12%. The pH values of the vinegar samples were in range of 3.85~4.46 after 25 days fermentation, and the sugar contents were highest after 9 days of fermentation (12.00~13.50 °Brix). The total polyphenol concents of vinegars were in the range of 20.65~52.04 mg/100 mL 25 days fermentation. Pyrogallol and vanillic acid were detected in the completely fermented vinegars, and their contents increased with black garlic content. Five organic acids (lactic acid, acetic acid, citric acid, succinic acid and propionic acid) were detected after 25 days of fermentation, with the total amount of organic acids being 5,327.34~6,307.64 mg/100 mL, and the total abetic acid contents beging the highest of the organic acids at 4208.90~5,570.29 mg/100 mL. After 25 days of fermentation, the total minerals contents were higher, and depending on the quantity of black garlic added. Of the minerals, the of potassium content was the highest (366.23~1,619.67 mg/L).

Conservation and chemical composition of Leucaena Leucocephala plus fresh or wilted Pennisetum purpureum mixed silages

ABSTRACTObjective. Quantify the effects of mixing Leucaena (L) with King grass forage, fresh (K) or wilted (Kp), on the fermentation process and chemical composition of mixed silages. Materials and methods. Silos were produced mixing several proportions (kg:kg) K:L and Kp:L (100:0; 75:25; 60:40; 50:50; 40:60 and 0:100) of both types of plants, under a completely randomized design of four replications. The quantity of organic acids (butyric, acetic, lactic), pH, ammonia nitrogen percent and some of the typical bromatologic nutrients of the forage before and after ensiling were measured. The treatment effects were evaluated through variance and regression analysis. Results. The results clearly proved the differences (p&lt;0.05) between King grass and Leucaena which promote its mixing and wilting: better legume contents of crude protein (24 vs. 7%), dry matter (33.77 vs. 22.05%) and crude fiber (26.53 vs. 32.5%). Clear benefits on the conservation process of mixed silages were also measured: higher lactic productions and less butyric, acceptable pH (4.02-4.8) and protein degradation (&lt;8%). In addition, a positive effect on the chemical composition of the aforementioned silages was quantified (crude protein, dry matter and crude fiber progressive improvement). Conclusions. Mixed K+L silages are better than pure K if L is included below 25% in KL and up to 40% when K has been wilted. Higher inclusions of L will worsen the conservation process and will limit its elaboration.

Effects of exogenous putrescine on glycolysis and Krebs cycle metabolism in cucumber leaves subjected to salt stress

The effects of exogenous putrescine (8 mmol L−1) on the carbohydrate content, glycolytic metabolism, citric acid cycle intermediates, key enzyme activities and their corresponding gene expression in cucumber (cucumis sativus L. cv. Jingyou NO.4) subjected to salt stress (75 mmol L−1 NaCl) in solution culture was studied. Phosphofructokinase (PFK), pyruvate kinase (PK) and phosphoenolpyruvate pyruvate kinase (PEPC) activities were significantly decreased in leaves when exposed to salt stress. NaCl stress caused the PFK and PK gene expression and the content of pyruvate to significantly decrease, while PEPC gene expression increased. Salt stress also significantly reduced isocitrate dehydrogenase, malate dehydrogenase and succinate dehydrogenase and their levels of transcription, causing decreases in the citric acid, succinic acid and malic acid content in leaves. Exogenous putrescine reversed the salt stress and increased gene expression and, in turn, the key enzymes involved in the glycolysis pathway and Krebs cycle, which significantly increased the amounts of organic acids and pyruvate produced, promoting the release of more energy currency (ATP and ADP). These results suggest that Put effectively participate glycolysis pathway and Krebs cycle, reducing the excessive accumulation of carbohydrates in the leaves, and providing more material and energy for the defense salt-induced injury, thus enhances cucumber seedling to salt stress tolerance.

Study for quality and amount of carbonic acids in the leaves of Urtica dioica L.

Search and elaboration of plant-based drugs which stimulate physiological functions of organism are key trend of current scientific researches.Aim. The identification and analysis of organic and fatty acids amount by gas chromate-mass-spectrometry on the chromatograph Agilent Technology 6890N with mass-spectrometric detector 5973N, has been performed to assess the amount of some species of carbonic acids in the leaves of Urtica dioica.Methods and results. Components have been identified accordingly to the comparison results of mass-spectra substances separated within chromatography with the data in references for mass-spectra NIST02 and WILEY 2007. 14 Organic and 17 fatty acids have been identified. Citric acid predominated in organic acids (50.65%), palmitic (33.19%), linolenic (32.50%), linoleic (20.27%) were prevailing in fatty acids. The total amount of organic acids was 1776.6 mg/kg, fatty ones was 15731.9 mg/kg.Conclusion. The obtained results convinced that researches on raw materials from Urtica dioica as a source of natural biologic substances for manufacturing mono-and polycomponent phytodrugs are promising.

Enhanced succinic acid production in Aspergillus saccharolyticus by heterologous expression of fumarate reductase from Trypanosoma brucei.

Aspergillus saccharolyticus exhibits great potential as a cell factory for industrial production of dicarboxylic acids. In the analysis of the organic acid profile, A. saccharolyticus was cultivated in an acid production medium using two different pH conditions. The specific activities of the enzymes, pyruvate carboxylase (PYC), malate dehydrogenase (MDH), and fumarase (FUM), involved in the reductive tricarboxylic acid (rTCA) branch, were examined and compared in cells harvested from the acid production medium and a complete medium. The results showed that ambient pH had a significant impact on the pattern and the amount of organic acids produced by A. saccharolyticus. The wild-type strain produced higher amount of malic acid and succinic acid in the pH buffered condition (pH 6.5) compared with the pH non-buffered condition. The enzyme assays showed that the rTCA branch was active in the acid production medium as well as the complete medium, but the measured enzyme activities were different depending on the media. Furthermore, a soluble NADH-dependent fumarate reductase gene (frd) from Trypanosoma brucei was inserted and expressed in A. saccharolyticus. The expression of the frd gene led to an enhanced production of succinic acid in frd transformants compared with the wild-type in both pH buffered and pH non-buffered conditions with highest amount produced in the pH buffered condition (16.2 ± 0.5 g/L). This study demonstrates the feasibility of increasing succinic acid production through the cytosolic reductive pathway by genetic engineering in A. saccharolyticus.

Phosphorus release from the soils in the Yellow River Delta: dynamic factors and implications for eco-restoration

Root-released organic acids are reported to increase phosphorus (P) availability in the soil. In this study a dynamic study of P release from soil was conducted to get more exact information of the organic acids role in P availability in soil. The results show that organic acids in different concentrations significantly affected P release. In a concentration of 10 mmol/L, no significant differences can be observed among citric acid, malic acid and acetic acid in terms of their effect on the release of soil P. However, when the concentration reduced to 1 mmol/L, both the total release amount and the maximum release amount of soil P significantly declined, and the decline degree were citric acid malic acid > acetic acid > oxalic acid. The higher the concentration of the organic acids was, the higher the migration rate of P would be. Given that the P needed by plants basically migrates by means of diffusion, under the condition of P deficiency of plants, improving the secretion amount of organic acids can effectively increase the biological utilization rate of P.

Effect of Extraction and Processing Conditions on Organic Acids of Barberry Fruits

The bioactive compounds of barberry such as organic acids are widely used in medical and food industries. The effects of extraction and processing conditions including varieties (B. integerrima: A, B. vulgaris: P), solvents (water: W, ethanol: E), light (presence: L or absence: T), pH (3 and 1.5), temperatures (25 and 50C), processes of heating (at 95 and 80C), chilling (ref. 1 and 2 months), freezing (con), microwave (mic) and gamma irradiation (at doses of 0.5–10 kGy) on organic acid profile were studied. The highest (acetic, malic and ascorbic) and lowest (fumaric) amounts (mg/100g extract) of organic acids in extraction conditions were as follows: acetic in AWT325 (23,124.53 ± 747.33), malic in PET1.525 (21,035.18 ± 21.05), ascorbic in AET350 (19,796.20 ± 104.44) and fumaric in PWL325 (62.30 ± 0.45). The highest and lowest amounts of organic acids in processing conditions were as follows, respectively: acetic (Amic 17,915.07 ± 164.38) and fumaric (Acon 38.84 ± 1.44). Practical Applications The Berberis vulgaris fruit is useful as tonic for liver and heart; it prevents chronic bleeding; reduces mucus, triglycerides, cholesterol and blood pressure; and also purifies the blood. It is effective in the treatment of gallbladder, bleeding hemorrhoids, antiparasitic liver, diabetes, gout, kidney stones, colon cancer, prostate inflammation, malaria, fever, asthma and neurological diseases. Owing to its color and mellow taste B. vulgaris fruit is used as a seasoning in Persian food. Barberry fruits are used in preparing sauces, jellies, carbonated drinks, candies, food color powders, jams, marmalades, chocolates and nectars. B. integerrima fruits are used to prepare juices. The use of barberry fruit as a natural food colorant rich in anthocyanins instead of harmful artificial ones was studied by researchers. In addition, barberry fruits contain polyphenols with beneficial antioxidant activities that reduce damages due to free radicals and prevent chronic diseases and cancers.

L-lactic acid production by Aspergillus brasiliensis overexpressing the heterologous ldha gene from Rhizopus oryzae

BackgroundLactic acid is the building block of poly-lactic acid (PLA), a biopolymer that could be set to replace petroleum-based plastics. To make lactic acid production cost-effective, the production process should be carried out at low pH, in low-nutrient media, and with a low-cost carbon source. Yeasts have been engineered to produce high levels of lactic acid at low pH from glucose but not from carbohydrate polymers (e.g. cellulose, hemicellulose, starch). Aspergilli are versatile microbial cell factories able to naturally produce large amounts of organic acids at low pH and to metabolize cheap abundant carbon sources such as plant biomass. However, they have never been used for lactic acid production.ResultsTo investigate the feasibility of lactic acid production with Aspergillus, the NAD-dependent lactate dehydrogenase (LDH) responsible for lactic acid production by Rhizopus oryzae was produced in Aspergillus brasiliensis BRFM103. Among transformants, the best lactic acid producer, A. brasiliensis BRFM1877, integrated 6 ldhA gene copies, and intracellular LDH activity was 9.2 × 10−2 U/mg. At a final pH of 1.6, lactic acid titer reached 13.1 g/L (conversion yield: 26%, w/w) at 138 h in glucose-ammonium medium. This extreme pH drop was subsequently prevented by switching nitrogen source from ammonium sulfate to Na-nitrate, leading to a final pH of 3 and a lactic acid titer of 17.7 g/L (conversion yield: 47%, w/w) at 90 h of culture. Final titer was further improved to 32.2 g/L of lactic acid (conversion yield: 44%, w/w) by adding 20 g/L glucose to the culture medium at 96 h. This strain was ultimately able to produce lactic acid from xylose, arabinose, starch and xylan.ConclusionWe obtained the first Aspergillus strains able to produce large amounts of lactic acid by inserting recombinant ldhA genes from R. oryzae into a wild-type A. brasiliensis strain. pH regulation failed to significantly increase lactic acid production, but switching nitrogen source and changing culture feed enabled a 1.8-fold increase in conversion yields. The strain produced lactic acid from plant biomass. Our findings make A. brasiliensis a strong contender microorganism for low-pH acid production from various complex substrates, especially hemicellulose.

Biological soil disinfestation using bioethanol fermentation products: role of residual organic substances

We evaluated the efficacy of biological soil disinfestation (BSD) using bioethanol fermentation products (ethanol fermentation solution and crude alcohol) from forage rice plants and sweet sorghum to control the soil-borne pathogen Fusarium oxysporum f. sp. lycopersici (Fol), which causes Fusarium wilt of tomato. In the pot tests, the survival of bud cells markedly declined after 14 days in the soil saturated with diluted bioethanol fermentation products, which contained more than 0.25 % (v/v) ethanol. In the Fol-suppressed soil, a sudden drop of soil oxidation–reduction potential (ORP) below −200 mV and accumulation of acetic acid and Fe2+ were observed during the disinfestation treatment. The bioethanol fermentation products included a certain amount of organic acids (e.g., acetic acid and l-lactic acid) and sugars (e.g., d-glucose, sucrose, and d-xylose), and the treatment with each of these organic substances, as well as ethanol, had a fungicidal effect against Fol in the soil. Thus, the residual organic substances in the bioethanol fermentation products seemed to enhance the fungicidal effect of the ethanol-based BSD treatment. BSD tests in field soil were repeated four times during the spring and autumn for 2 years. Fol was strongly suppressed in the soil that was irrigated with 0.5 or 1.0 % (v/v) bioethanol solution and subsequently covered with a plastic film for 21 days, while the treatment with wheat bran or 1.0 % (v/v) ethanol did not always suppress Fol.