Showing 5 results for Organic Acids
Volume 12, Issue 49 (10-2015)
Abstract
The ability of bacteria to tolerate low pH is a very important trait to survive in a variety of environments. In the literature, there is a lot of information about the acid tolerance of different bacteria. However, little is known about the acid tolerance of Morganella morganii, the most prolific histamine former in fish and seafood products. Therefore, in the present study, the effect of growth phase, type of acid and medium on the acid tolerance of M. morganii at different pHs were evaluated. To achieve this purpose, cells of M. morganii in exponential or stationary growth phases were exposed to low pHs (3, 4 and 5) adjusted by adding hydrochloric, acetic, lactic, citric or tartaric acids into TSB or PBS for one hour. Survival percentage was obtained by dividing the surviving population by the initial population. In general, results of the present study showed a high acid tolerance of M. morganii. For all the acids tested, the lower the pH of the mediums used, the lower the survival percentage observed. Cells of M. morganii in the stationary phase were more resistant to acidic conditions tested and no significant difference was observed (p<0.05) in the acid tolerance of M. morganii in TSB and PBS at different pHs. In addition, acetic acid and lactic acid showed more antimicrobial effect on both the stationary and exponential phase cells than the other acids use.
Rasool Zare, Abdolmohammad Abedian Kenari,
Volume 13, Issue 2 (6-2024)
Abstract
The use of probiotics and organic acids is an ideal and suitable alternative to antibiotics in aquaculture. Currently, there is not enough knowledge about the specific and combined effects of these additives in the diet of sturgeon. Therefore, the aim of this research was to evaluate the use of lactic acid and probiotic supplements (Protexin) and their combination in the diet of Siberian sturgeon (Acipenser baerii). Therefore, 160 healthy fish with an average body weight of 54.85 ± 0.36 grams were randomly divided into 4 experimental groups in 3 replicates. Fish were fed four diets including a control diet without additives (diet 1), a control diet with 2% lactic acid (diet 2), a control diet with a combination of 2% lactic acid and 0.01% Protexin (diet 3), and a control diet with 0.01% Protexin (diet 4). Fish were fed three times a day to satiation for 9 weeks. At the end of the experiment, growth and physiological parameters were measured. The results showed that lactic acid alone and in combination with Protexin increased body weight and specific growth rate. The feed conversion ratio decreased in treatments where lactic acid was used alone or in combination with Protexin (P<0.05). Mortality rates were zero in all treatments during the experimental period. The carcass protein of Siberian sturgeon in diets supplemented with a combination of lactic acid and Protexin showed significant improvement compared to other groups (P<0.05). Addition of lactic acid and Protexin either separately or in combination led to a decrease in carcass fat content (P<0.05). The lowest intestinal pH was observed in the diet supplemented with lactic acid along with Protexin, while the highest was in the control group. Additionally, the total number of lactic acid bacteria in the intestines of fish fed with lactic acid along with Protexin showed a significant increase compared to other treatments (P<0.05). The combined addition of lactic acid with Protexin significantly increased lysozyme and complement activity in fish blood (P<0.05). In general, the separate and combined use of lactic acid (2 %) and Protexin (0.01 %) in the diet of Siberian sturgeon improved the performance of this fish.
Volume 14, Issue 7 (12-2012)
Abstract
Campylobacter is known to be one of the most common causes of human intestinal disorders. Since poultry are known to be the main reservoirs for this pathogen, decreasing this bacterium in intestinal tract could be beneficial in reducing contamination of poultry products. The effects of probiotic (PrimaLac®), medicinal plant (Sangrovit®) and organic acid (Selko-pH®) as broiler feed additives on cecal colonization, and fecal excretion of broilers were studied. Other parameters such as performance, immune response and intestinal morphology were also determined. A total of 300 broiler chicks (Cobb 500) were divided into 5 groups. Groups consisted of unsupplemented feed (negative and positive controls), probiotic, medicinal plant and drinking water containing organic acid mixture. Except for the negative control group, all chickens were orally challenged with (109 cfu mL-1) Campylobacter jejuni at day 21. Cecal and fecal samples were collected for Campylobacter count. Body weight (BW), feed intake (FI) and feed conversion ratio (FCR) were determined weekly and cumulatively. BW and FI in the probiotic treated group were higher (P< 0.05) than the positive control group. On day 49 all supplemented treatments showed a reduction of Campylobacter colonization in cecal contents (P< 0.05). Fecal samples showed reductions (P< 0.05) on day 35 and 42. Villi height of duodenum and jejunum in the probiotic and medicinal plant treated groups were improved (P< 0.05). Immune response was significantly higher in these two groups (P< 0.05). These effects could be due to the antibacterial effects of the used feed supplements. Our results indicate that these feed additives could be potential treatments for reducing Campylobacter in the intestine of broilers. Probiotic and medicinal plant improve growth performance of these birds.
Volume 16, Issue 86 (4-2019)
Abstract
Industrial lemon juice may contain unauthorized additives that can lead to various diseases in society. As a result, it is highly important to use effective methods to identify the fake lemon juice. In this study, for the first time in our country, detection of cheating in industrial lemon juice in Golestan province is presented by analyzing organic acids, including citric acid, isocytic acid, malic acid, and also determining the ratio between citric acid and isocytic acid using liquid chromatography-mass spectrometry. The accuracy of the proposed method was confirmed by analyzing natural lemon juice samples. The limits of detection and quantification were 2 and 5, 0.02 and 0.05, 0.2 and 0.5 mg L-1 for citric acid, isocytic acid, malic acid, respectively. Industrial lemon juice samples were selected from commercially available brands, and fake samples were detected by comparison of the amounts of organic acids with the authorized values set by the European Standard. The results showed that the proposed method is very effective and sensitive in detecting cheating samples of industrial lemon juice.
Volume 21, Issue 5 (9-2019)
Abstract
This study was conducted in field conditions to determine the response of cabbage to four different irrigation levels, from 2015 to 2016. The experiment was laid out in randomized block design. Plots were irrigated using a drip irrigation system and the irrigation interval was fixed as 4 days for all treatments. Evaporation was determined by Class-A pan. Six organic acids (ascorbic, tartaric, lactic, citric, malic and oxalic) were identified and quantified by HPLC-UV. White cabbage yields were significantly increased by water applications, but deficit irrigation produced negative results. Maximum amounts of ascorbic, lactic, tartaric and malic acids were found in the low water content treatment, while reducing sugar and total sugar increased in the full irrigation treatment. In the study, supplying different amounts of irrigation water caused changes in the growth and quality of white cabbage (Brassica oleracea L.cv. Capitata). When water stress in cabbage production exceeded more than 30%, the yield and, especially, the quality of cabbage decreased significantly. The results revealed evidence that different soil moisture content in the root depth affected the yield, organic acids, and sugar content.
