scholarly journals Utilization of maltose enriched spent grains liquor for xanthan production

2011 ◽  
pp. 211-221 ◽  
Author(s):  
Jelena Dodic ◽  
Damjan Vucurovic ◽  
Jovana Grahovac ◽  
Sinisa Dodic ◽  
Stevan Popov ◽  
...  

The present study examines xanthan production by Xanthomonas campestris under aerobic conditions on spent grains liquor based cultivation media containing four different amounts of maltose. All four experiments were performed simultaneously, so that all stages of the biotechnological process would be carried out under identical conditions. In addition to the cultivation parameters (pH value, contents of dissolved oxygen, reducing sugars and assimilable nitrogen, turbidity and trickling time), xanthan yield and sugar conversion percentage were also determined. Based on the results of the experiments maltose addition up to 5% to spent grains liquor does not hinder the cultivation course. On the other hand, the conversion of sugars into xanthan decreases with the increase of maltose content to 5% and a large amount of sugars lags in the cultivation broth.

2017 ◽  
Vol 71 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Zorana Roncevic ◽  
Bojana Bajic ◽  
Damjan Vucurovic ◽  
Sinisa Dodic ◽  
Jovana Grahovac ◽  
...  

Wine industry generates large volumes of wastewaters resulting from numerous cleaning operations that occur during the different stages of winemaking. Disposal of these effluents in the environment causes huge problems due to their high organic and inorganic load and seasonal variability. The bioconversion of winery wastewaters in valuable product, such as xanthan, is an important alternative to overcome environmental problems. In this research, the possibility of xanthan production using Xanthomonas campestris on blended wastewaters from different stages of white and rose wine production with initial sugar content of 50 g/L was investigated. In addition to the media parameters (content of sugars, total and assimilable nitrogen, phosphorus, total dissolved salts and apparent viscosity), raw xanthan yield and degree of sugar conversion into product were determined in order to examine the success of xanthan biosynthesis. In applied experimental conditions, xanthan yield of 20.92 and 30.64 g/L and sugar conversion into product of 40.23 and 60.73% were achieved on wastewaters from white and rose wine production, respectively. The results of these experiments suggest that winery wastewaters, after additional optimization of the process in terms of the substrate composition and the cultivation conditions, may be a suitable raw material for industrial xanthan production.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 557d-557
Author(s):  
Jennifer Warr ◽  
Fenny Dane ◽  
Bob Ebel

C6 volatile compounds are known to be produced by the plant upon pathogen attack or other stress-related events. The biological activity of many of these substances is poorly understood, but some might produce signal molecules important in host–pathogen interactions. In this research we explored the possibility that lipid-derived C6 volatiles have a direct effect on bacterial plant pathogens. To this purpose we used a unique tool, a bacterium genetically engineered to bioluminesce. Light-producing genes from a fish-associated bacterium were introduced into Xanthomonas campestris pv. campestris, enabling nondestructive detection of bacteria in vitro and in the plant with special computer-assisted camera equipment. The effects of different C6 volatiles (trans-2 hexanal, trans-2 hexen-1-ol and cis-3 hexenol) on growth of bioluminescent Xanthomonas campestris were investigated. Different volatile concentrations were used. Treatment with trans-2 hexanal appeared bactericidal at low concentrations (1% and 10%), while treatments with the other volatiles were not inhibitive to bacterial growth. The implications of these results with respect to practical use of trans-2 hexanal in pathogen susceptible and resistant plants will be discussed.


2015 ◽  
Vol 41 (1) ◽  
pp. 13-19
Author(s):  
Kaniz Fatema ◽  
Wan Maznah Wan Omar ◽  
Mansor Mat Isa

Water quality in three different stations of Merbok estuary was investigated limnologically from October, 2010 to September, 2011. Water temperature, transparency and total suspended solids (TSS) varied from 27.45 - 30.450C, 7.5 - 120 cm and 10 -140 mg/l, respectively. Dissolved Oxygen (DO) concentration ranged from 1.22-10.8 mg/l, while salinity ranged from 3.5-35.00 ppt. pH and conductivity ranged from 6.35 - 8.25 and 40 - 380 ?S/cm, respectively. Kruskal Wallis H test shows that water quality parameters were significantly different among the sampling months and stations (p<0.05). This study revealed that DO, salinity, conductivity and transparency were higher in wet season and TSS was higher in dry season. On the other hand, temperature and pH did not follow any seasonal trends.Bangladesh J. Zool. 41(1): 13-19, 2013


2011 ◽  
Vol 51 (3) ◽  
pp. 283-288 ◽  
Author(s):  
Cíntia Regina Rodrigues Carignatto ◽  
Kassandra Sussi Mustafé Oliveira ◽  
Valéria Marta Gomes de Lima ◽  
Pedro de Oliva Neto

1970 ◽  
Vol 33 (11) ◽  
pp. 516-520 ◽  
Author(s):  
T. E. Minor ◽  
E. H. Marth

The effect of gradually reducing the pH of pasteurized milk with acetic, citric, hydrochloric, lactic, and phosphoric acids over periods of 4, 8, and 12 hr on growth of Staphylococcus aureus 100 in this substrate was determined. In addition, 1: 1 mixtures of lactic acid and each of the other acids, and of acetic and citric acids were evaluated for their effect on growth of this organism. To achieve a 90% reduction in growth over a 12 hr period, a final pH value of 5.2 was required for acetic, 4.9 for lactic, 4.7 for phosphoric and citric, and 4.6 for hydrochloric acid. A 99% reduction during a 12 hr period was obtained with a final pH value of 5.0 for acetic, 4.6 for lactic, 4.5 for citric, 4.1 for phosphoric, and 4.0 for hydrochloric acid. A pH value of 3.3 was required for a 99.9% reduction with hydrochloric acid, whereas the same effect was produced at a pH value of 4.9 with acetic acid. Correspondingly lower pH values were required to inhibit growth within 8 and 4 hr periods. Mixtures of acids adjusted to pH values at the borderline for growth (12 hr period) exhibited neither synergistic nor antagonistic effects between two acids.


2019 ◽  
Vol 6 (2) ◽  
pp. 301-313
Author(s):  
Taslima Akter ◽  
Shampa Rani Ghosh ◽  
Sitesh Chandra Sarker ◽  
Md Mokhlesur Rahman ◽  
KM Eadun Nabi

Ponds are considered to be self-contained, land lock ecosystem which is often teeming with rich vegetation and diverse organismal life. The pond water contains different organic and inorganic components. The experiment was carried out in laboratory, Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh through collection of pond water from Gouripur and Muktagacha under Mymensingh division for assessment of major ionic status and suitability parameters for irrigation and aquaculture usage in quantitative way. Around 30 samples were collected from different location. On the basis of HCO3 ion, all water samples except 3 samples were not suitable for irrigation because this anion exceeded the acceptable limit (1.5 meL-1). On the other hand, HCO3 ion was not treated as problematic in all samples except 2 samples for aquaculture usages. The concentrations of Ca, Mg, Na, K, PO4 and SO4 were far below the recommended limit. Considering aquaculture usage, Cl ion was considered as hazardous in all the pond water samples because this anion was above the legal limit (<0.003mgL-1). pH value of pond ranged from 7.02 to 7.87 indicating alkaline in nature and were not problematic for irrigation and aquaculture usage. Among the major ionic constituents, the remarkable significant correlations existed between Ca vs Mg, Ca vs K, Mg vs SO4, K vs Na, Na vs SO4. Res. Agric., Livest. Fish.6(2): 301-313, August 2019


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhaopeng Wang ◽  
Yi Wang ◽  
Bowei Zhang ◽  
Zhan Zhang ◽  
Kui Xiao ◽  
...  

Purpose The purpose of this paper is to investigate the influence of the potential of hydrogen (pH) and dissolved oxygen in artificial seawater on the passivation behavior of 316L stainless steel. Design/methodology/approach The corrosion behavior was studied by using electrochemical measurements such as electrochemical impedance spectroscopy and polarization curve. The passive films were characterized with X-ray photoelectron spectroscopy. Findings The polarization resistance of the passive film decreases as the pH value drops ascribed to the formation of much more point defects. The donor carrier concentration (ND) in the passive film formed in the deaerated condition is lower than that in aerated conditions. Nevertheless, this phenomenon is the opposite when the pH value is 1 due to the significant decrease of Fe oxides/hydroxides coupled with the stable content of Cr oxides/hydroxides species. In addition, the compositional variation of the passive film also leads to the changes of its semiconductor properties from N-type to bipolar type. Originality/value This paper shows the variation of polarization resistance, corrosion potential, passive film composition and semiconductor properties with the pH value and dissolved oxygen. The results can serve as references to the further study on crevice corrosion of 316L in seawater.


2011 ◽  
Vol 20 (No. 3) ◽  
pp. 113-115
Author(s):  
Ľ. Polívka ◽  
E. Fendrich ◽  
B. Škárka

The influence of ozone on some properties of fruit jams was studied. Ozone did not influence the pH value, the contents of reducing sugars and organic acids, or the sensoric properties of the fruit jams tested. It may be used as a&nbsp;source of sterile air over the jam surfaces in yoghurt production. &nbsp;


1964 ◽  
Vol 47 (5) ◽  
pp. 823-826
Author(s):  
James F Eheart ◽  
Blanche S Mason

Abstract Determinations were made of total and reducing sugars, sucrose, dextrin, and starch content of dry fat-free solids of the "total diet" samples previously reported by Food and Drug Administration. Samples represented differences in season, location, time of purchase, and store at which purchased. Mean dry fat-free solids contents did not differ significantly. Purchase periods and locations caused extreme variability of the sucrose content of the diets. Factor- effect variations among the other carbohydrate constituents were not considered nutritionally important. Reducing sugars, sucrose, and starch gave positive correlations with total sugars, while negative correlations were obtained for total sugars with dextrin and for reducing sugars with sucrose.


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