Brown pigmentation of Xanthomonas campestris pv. phaseoli associated with homogentisic acid

1994 ◽  
Vol 40 (1) ◽  
pp. 28-34 ◽  
Author(s):  
P. H. Goodwin ◽  
C. R. Sopher

The diffusible brown pigment produced by some strains of Xanthomonas campestris pv. phaseoli was found to be due to the secretion and subsequent oxidation of homogentisic acid (2, 5-dihydroxyphenylacetic acid) rather than tyrosinase activity as previously reported. Homogentisic acid is an intermediate in tyrosine catabolism for a number of bacteria. Brown-pigmented strains appeared to be disrupted in tyrosine catabolism and could not use tyrosine as a nutrient. Nonpigmented strains, however, could utilize tyrosine as a nutrient, and although they secreted homogentisic acid, the levels were approximately 1/100th that of brown-pigmented strains. Production of brown pigment was stimulated by tyrosine and repressed by glucose. Growth in glucose resulted in a drop in the pH of the media, and the greatest pigment formation was associated with a shift to alkaline conditions in the culture media. By buffering the media near pH 7.0, brown pigment formation was repressed, even though unoxidized homogentisic acid accumulated in the culture media. The disruption of tyrosine catabolism corresponds to other reports describing differences between brown-pigmented and nonpigmented strains, and provides further support for the retention of a special taxonomic status for the brown-pigmented strains.Key words: homogentisic acid, pigments, Xanthomonas, fuscans.


2001 ◽  
Vol 67 (8) ◽  
pp. 3463-3468 ◽  
Author(s):  
Alexandra Carreira ◽  
Luı́sa M. Ferreira ◽  
Virgı́lio Loureiro

ABSTRACT Yarrowia lipolytica produces brown extracellular pigments that correlate with tyrosine catabolism. During tyrosine depletion, the yeast accumulated homogentisic acid,p-hydroxyphenylethanol, andp-hydroxyphenylacetic acid in the medium. Homogentisic acid accumulated under all aeration conditions tested, but its concentration decreased as aeration decreased. With moderate aeration, equimolar concentrations of alcohol andp-hydroxyphenylacetic acid (1:1) were detected, but with lower aeration the alcohol concentration was twice that of the acid (2:1). p-Hydroxyphenylethanol andp-hydroxyphenylacetic acid may result from the spontaneous disproportionation of the corresponding aldehyde,p-hydroxyphenylacetaldehyde. The catabolic pathway of tyrosine in Y. lipolytica involves the formation ofp-hydroxyphenylacetaldehyde, which is oxidized top-hydroxyphenylacetic acid and then further oxidized to homogentisic acid. Brown pigments are produced when homogentisic acid accumulates in the medium. This acid can spontaneously oxidize and polymerize, leading to the formation of pyomelanins. Mn2+accelerated and intensified the oxidative polymerization of homogentisic acid, and lactic acid enhanced the stimulating role of Mn2+. Alkaline conditions also accelerated pigment formation. The proposed tyrosine catabolism pathway appears to be unique for yeast, and this is the first report of a yeast producing pigments involving homogentisic acid.



2007 ◽  
Vol 7 ◽  
pp. 525-532
Author(s):  
Qing Guo ◽  
Zao-he Wu ◽  
Ming-liang Qian ◽  
Binhe Gu

The purpose of this study was to investigate the roles of coral sands in the enrichment and isolation of ammonium-oxidizing bacteria (AOB). We hypothesized that the porous coral sands provided additional surface area and nutrients for the growth of periphytic AOB. In the present study, an orthogonal test was designed to compare the AOB conversion rates of ammonium-nitrogen (NH4+N) to nitrite-nitrogen (NO2--N) among various combinations of culture media. Results showed that the conversion of NH4+N to NO2--N increased significantly when the coral sands were added, implying that coral sands were beneficial to the growth of AOB. Additions of potassium dihydrogen phosphate (KH2PO4) or sodium bicarbonate (NaHCO3) to the media became unnecessary when coral sands were used, but the addition of KH2PO4was needed when the molar nitrogen to phosphorus (N:P) ratio reached 10 in the enrichment media using calcium carbonate (CaCO3) powder as a calcium source.



Author(s):  
Gabriela de Oliveira Fernandes ◽  
Marcella Pecora Milazzotto ◽  
Andrei Antonioni Guedes Fidelis ◽  
Taynan Stonoga Kawamoto ◽  
Ligiane de Oliveira Leme ◽  
...  

Abstract The present study aimed to identify biomarkers to assess the quality of in vitro produced (IVP) bovine embryos in the culture media. IVP embryos on Day (D) 5 of development were transferred to individual drops, where they were maintained for the last 48 h of culture. Thereafter, the medium was collected and the embryos were transferred to the recipients. After pregnancy diagnosis, the media were grouped into the pregnant and nonpregnant groups. The metabolic profiles of the media were analyzed via electrospray ionization mass spectrometry, and the concentrations of pyruvate, lactate, and glutamate were assessed using fluorimetry. The spectrometric profile revealed that the media from embryos from the pregnant group presented a higher signal intensity compared to that of the nonpregnant group; the ions 156.13 Da [M + H]+, 444.33 Da [M + H]+, and 305.97 Da [M + H]+ were identified as biomarkers. Spent culture medium from expanded blastocysts (Bx) that established pregnancy had a greater concentration of pyruvate (p = 0.0174) and lesser concentration of lactate (p = 0.042) than spent culture medium from Bx that did not establish pregnancy. Moreover, pyruvate in the culture media of Bx can predict pregnancy with 90.9% sensitivity and 75% specificity. In conclusion, we identified markers in the culture media that helped in assessing the most viable IVP embryos with a greater potential to establish pregnancy.



HortScience ◽  
2018 ◽  
Vol 53 (10) ◽  
pp. 1487-1493 ◽  
Author(s):  
Doina Clapa ◽  
Claudiu Bunea ◽  
Orsolya Borsai ◽  
Adela Pintea ◽  
Monica Hârța ◽  
...  

The current research was carried out to investigate the effects of iron source in the culture media for Vaccinium corymbosum L. ʻBluerayʼ, ʻDukeʼ, and ʻPatriotʼ cultivars grown on five different types of medium (Woody Plant Medium supplemented with 1.0 mg·L−1 zeatin and 0, 25, 50, 75, and 100 mg·L−1 Sequestrene 138). After 10 weeks of culture, seven physiological parameters were measured, such as the number and length of axillary shoots, rooting and acclimatization percentage, as well as chlorophyll (a, b, a/b) and carotenoid content of the leaves. Adding Sequestrene 138 to the culture media led to a slight decrease of the proliferation rate but increased the length of the shoots. The chlorophyll and carotenoid content in all of the three cultivars was considerably increased as the iron concentration of the media increased. The shoots developed on the Sequestrene 138–free medium were chlorotic and short, whereas at different concentrations of iron in the culture medium the shoots were dark green and vigorous, providing a greater acclimatization success than those grown in iron-free medium.



2021 ◽  
Vol 21 (103) ◽  
pp. 18518-18532
Author(s):  
Norah Vhangani Lusani ◽  
◽  
L Mogashoa ◽  
J Van Wyk

The antioxidant and anti-browning activity of heated plant extracts have been attributed to the formation of Maillard reaction products (MRPs) via the Maillard reaction (MR). The inhibitory effect of heated Moringa oleifera (MO) seed extract on banana polyphenol oxidase (PPO) was investigated. The Plain MO seed extracts and those with added glucose and glycine (1.5 mM each) were heated at 100°C for 15, 30, 60 and 120 min. The pH and brown colour development decreased and increased significantly (P <0.05) with increased reaction time, respectively, with heated moringa glucose-glycine HMGGL for 120 min exhibiting the highest pH reduction (2.58) and darkest extracts at an L* value of 8.11. This phenomenon is associated with progression of the MR. With reference to enzymatic browning, heated MO seed extracts exhibited stronger inhibitory effect against banana PPO activity in vivo and in vitro than the unheated counterpart. Evident to this are the higher inhibition percentages and lower ΔE values. Among model systems, the highest in vitro browning inhibition was exhibited mostly by longer heating times of 60 and 120 min. Model system HMGGL 120 min proved to be superior at 96% inhibition, which was comparable to known synthetic commercial antioxidants such as ascorbic acid (AA) at 99%, as well as ethylenediaminetetraacetic acid (EDTA) and citric acid (CA), both at 100% inhibition. In vivo enzymatic browning inhibition followed a similar trend, where the brown pigment (melanin) intensified as shown by an increase in ΔE as the storage time increased from 0.5 to 24 h. The model system UMGGL exhibited highest inhibition of brown melanin (p <0.05). Although it was the best amongst other model systems, it was surpassed by synthetic antioxidants AA, EDTA and CA, which were ranked amongst the top three in inhibiting brown pigment formation in vivo. To further illustrate the effect of MR augmented MO seed extracts on enzyme activity inhibition, UMGGL 60 and 120 at 5 and 24 h storage surpassed the inhibitory effect of AA. At the said storage times, AA lost its inhibitory potential against pigment formation. This was due to oxidation of AA to form dehydroascorbic acid, which lacks inhibitory potential. This study proved that heating MO plant extracts increases their enzymatic browning inhibition potential, furthermore, the inhibitory capacity was heightened when reacted via the MR.



2019 ◽  
Vol 4 (2) ◽  
pp. 128
Author(s):  
Adnan Kharisma, Abdul Manan

Abstract The abundance of bacteria is an activity that aims to determine the distribution and the abundance of bacteria in a water area, so an effort to control and prevent against these bacteria can be made to avoid it’s wide spread. The function of this monitoring activities is for an early detection of animal health conditions that is the white leg shrimp due to bacterial attack. Given the importance of health level in the cultivation of white leg shrimp, then the monitoring activity in bacterial abundance should be done because the number of bacteria found in aquatic environments shouldn’t exceed the minimum threshold number of bacteria that is 104 CFU/ml. The purpose of this study case is to know the abundance of Vibrio sp. on white leg shrimp water augmentation. Because the Vibrio sp. bacteria is known as the opportunistic pathogen of white leg shrimp, which can cause disease if the environmental conditions are bad. Working methods used is descriptive method of data collection techniques include primary and secondary data. The stage of the monitoring activity include: (1) Preparation phase which includes the preparation of equipment and materials and sterilization equipment and media. (2) Phase of making trisalt solvent and bacterial culture media. (3) Phase of retrieval and delivery the water samples. (4) Phase planting the water samples. (5) Phase counting the bacteria. (6) Interpretation the results of the calculation. Based on the results of monitoring the abundance of bacteria in white leg shrimp water augmentation activity, the conclusion is the abundance of Vibrio sp. on white leg shrimp water augmentation has exceeds the minimum threshold number of bacteria that is 104 CFU/ml, so the white leg shrimp culture is susceptible againts these Vibriosis disease.



2020 ◽  
Author(s):  
Mariana Ferdes ◽  
Rodica Roxana Constantinescu

The chrome shavings waste obtained as a result of the leather finishing process accumulates in a large volume in tanneries and represent a major problem for the environment. This waste are particularly resistant to attack of microorganisms, due to the significant concentration of chromium and are thus difficult to degrade. In this study, chrome shavings were analyzed microbiologically by determining the total number of germs and the number of yeasts and molds on specific culture media. Several bacterial and fungal strains were isolated from the cultures in Petri dishes, after the growth of the colonies. These strains were characterized in terms of the production of proteolytic enzymes, by a method of screening on the media with casein, which allows the determination of proteolytic indices of microorganisms. As a result of the tests performed, five bacterial strains probably belonging to the genus Bacillus and two fungal strains from the genera Penicillium and Cladosporium were selected.



2021 ◽  
Vol 8 (3) ◽  
pp. 202-211
Author(s):  
Ase Lestari ◽  
T.H Wahyuni ◽  
T.H Wahyuni ◽  
E. Mirwandhono ◽  
N. Ginting

Maggot black soldier fly (Hermetia illucens) is an insect that is environmentally friendly and can be mass produced and does not compete with humans. In addition, insect cultivation can reduce organic waste that has the potential to pollute the environment. Maggot black soldier fly (Hermetia illucens) has a high crude protein content of 42.1%. The length of the life cycle and the high and low nutrient content of the maggot are influenced by the maggot growing media used. In this study using EM4 as a bio-activator for fermentation of rice bran, coconut dregs, tofu dregs and palm kernel cake. The function of this fermentation is to increase the nutrients contained in this material which will later be used as a growing medium for maggot and maggot is one of the alternatives to feed protein sources from fish meal. The study was conducted experimentally using a completely randomized design (CRD) 5 treatments and 4 replications, with the weight of each experimental unit the media content is 1 kg and filled with 1 g of BSF eggs and the media size is 37 cm long, 26 cm wide and 10 cm high. The parameters of this study consisted of maggot production and maggot nutritional content, namely moisture content, ash content, crude protein, crude fat and carbohydrates. Based on research results P0 (100% fermented rice bran) obtained an average maggot production of 525g, KA maggot 8,16%, KAb maggot 7,83%, PK maggot 44,82%, LK maggot 21,62% and 17.58% maggot carbohydrates respectively. P1 (50% fermented rice bran + 50% fermented coconut dregs) obtained an average maggot production of 467.5g, KA maggot 9,57%, KAb maggot 9,03%, PK maggot 44,68%, LK maggot 20,51% and 16.20% maggot carbohydrates respectively. P2 (50% fermented rice bran + 50% fermented tofu dregs) obtained an average maggot production of 545.25g, KA maggot 9,02%, KAb maggot 8,32%, PK maggot 44,74%, LK maggot 18,57% and 20.09% maggot carbohydrates respectively. P3 (50% fermented rice bran + 50% palm kernel cake) obtained an average maggot production of 542g, KA maggot 9,16%, KAb maggot 9,22%, PK maggot 43,72%, LK maggot 19,87% and 18.02% maggot carbohydrates respectively. P4 (25% fermented rice bran + 25% fermented tofu dregs + 25% fermented coconut dregs + 25% palm kernel cake) obtained an average maggot production of 831.5g, KA maggot 9,08%, KAb maggot 9,35%, PK maggot 44,38%, LK maggot 17,01% and 20.18% maggot carbohydrates respectively. From the research results, it can be concluded that the use of culture media with a combination of 25% fermented rice bran + 25% fermented coconut dregs + 25% fermented tofu dregs + 25% fermented palm kernel meal is the best combination where the production reaches 831.5 g bsf and 20 carbohydrates. , 18% but could not increase moisture content, ash content, crude protein and crude fat.



Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 606 ◽  
Author(s):  
Aneta Wesołowska ◽  
Paula Jadczak ◽  
Danuta Kulpa ◽  
Włodzimierz Przewodowski

The aim of this study was to determine how the addition of gold and silver nanoparticles to culture media affects the composition of essential oils extracted from Lavandula angustifolia propagated on MS media with the addition of 10 and 50 mg·dm−3 of gold (24.2 ± 2.4 nm) and silver (27.5 ± 4.8 nm) nanocolloids. The oil extracted from the lavender tissues propagated on the medium with 10 mg·dm−3 AgNPs (silver nanoparticles) differed the most with respect to the control; oil-10 compounds were not found at all, and 13 others were detected which were not present in the control oil. The addition of AuNPs (gold nanoparticles) and AgNPs to the media resulted in a decrease of lower molecular weight compounds (e.g., α- and β-pinene, camphene, δ-3-carene, p-cymene, 1,8-cineole, trans-pinocarveol, camphoriborneol), which were replaced by those of a higher molecular weight (τ- and α-cadinol 9-cedranone, cadalene, α-bisabolol, cis-14-nor-muurol-5-en-4-one, (E,E)-farnesol).



1990 ◽  
Vol 258 (1) ◽  
pp. C109-C114 ◽  
Author(s):  
M. K. Raizada ◽  
B. Kimura ◽  
M. I. Phillips

Neuronal and glial cultures from the hypothalamic-brain stem areas of 1-day-old normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive (SH) rat brains stained positively with atrial natriuretic peptide (ANP)-specific antibodies. The endogenous levels of the ANP immunoreactivity in WKY neuronal and glial cultures were 17.0 +/- 2.2 and 14.3 +/- 2.7 pg/mg, respectively. Comparable neuronal and glial cultures from SH rat brains contained a 48 to 70% decrease in the endogenous ANP immunoreactivity levels. Culture media from both brain cell types also contained ANP immunoreactivity, the levels of which are significantly higher than those found in the cells. However, similar to endogenous levels, the media levels of immunoreactive ANP in SH neuronal and glial cultures were significantly reduced compared with WKY brain cultures. These observations demonstrate that endogenous ANP-like immunoreactivity is found in neuronal and glial cells and is released into the media. The levels of peptide are reduced in cultures of SH compared with WKY cultures, suggesting a genetically controlled difference between the hypertensive and normotensive rat strains long before hypertension develops.



Sign in / Sign up

Export Citation Format

Share Document