Chemical composition and antimicrobial activity of the essential oil of Syzygium aromaticum flower bud (Clove) against fish systemic bacteria isolated from aquaculture sites

This paper describes the chemical composition and antimicrobial activity of the essential oil of Syzygium aromaticum against Vibrio spp. (n = 6), Edwardsiella spp. (n = 21), Aeromonas spp. (n = 2), Escherichia coli (n = 2), Flavobacterium spp. (n = 1), Salmonella spp. (n = 2), Streptococcus spp. (n = 1) and Pseudomonas spp. (n = 1) isolated from aquaculture sites as well as seven reference strains of bacteria, namely, Escherichia coli (ATCC 25922), Citrobacter freundii (ATCC 8090), Aeromonas hydrophila (ATCC 49140), Pseudomonas aeruginosa (ATCC 35032), Streptococcus agalactiae (ATCC13813), Edwardsiella tarda (ATCC 15947) and Yersinia enterocolitica (ATCC 23715). Nowadays, most antibiotics are no longer effective in controlling diseases in aquaculture, especially fish systemic bacterial diseases, due to increasing incidences of antibiotic resistance among pathogenic bacteria. Furthermore, many countries have banned antibiotics in aquaculture use due to public health concerns and environmental hazards. Therefore, this study was carried out to evaluate the potential of the essential oil of S. aromaticum as an alternate commercial antibiotic to antimicrobial agents against fish systemic bacteria in aquaculture. The essential oil of S. aromaticum was prepared using a steam distillation method, and the chemical composition was analysed using Gas chromatography-mass spectroscopy (GC-MS). Minimum inhibitory concentration (MIC) values of the essential oils against the tested bacteria were determined using the broth two fold micro dilution method, with kanamycin and eugenol as positive controls. The MIC values of the essential oil of S. aromaticum ranged from 0.015 μg·mL⁻¹ to 0.062 μg·mL⁻¹ against the tested bacterial isolates. A total of nine chemical compounds were detected in the essential oil, with eugenol (49.0%) and caryophyllene (7.5%) being the major compounds. The results of the present study indicate that the essential oil of S. aromaticum shows a huge potential to substitute commercial antibiotics as antimicrobial agents for aquaculture use.     

Quantitation of fatty acids, sterols, and tocopherols in turpentine (Pistacia terebinthus Chia) growing wild in Turkey

The chemical composition (fatty acids, tocopherols, and sterols) of the oil from 14 samples of turpentine (Pistacia terebinthus L.) fruits is presented in this study. The oil content of the samples varied in a relatively small range between 38.4 g/100 g and 45.1 g/100 g. The dominating fatty acid of the oil is oleic acid, which accounted for 43.0 to 51.3% of the total fatty acids. The total content of vitamin E active compounds in the oils ranged between 396.8 and 517.7 mg/kg. The predominant isomers were alpha- and gamma-tocopherol, with approximate equal amounts between about 110 and 150 mg/kg. The seed oil of P. terebinthus also contained different tocotrienols, with gamma-tocotrienol as the dominate compound of this group, which amounted to between 79 and 114 mg/kg. The total content of sterols of the oils was determined to be between 1341.3 and 1802.5 mg/kg, with beta-sitosterol as the predominent sterol that accounted for more than 80% of the total amount of sterols. Other sterols in noteworthy amounts were campesterol, Delta5-avenasterol, and stigmasterol, which came to about 3-5% of the total sterols.     

Effect of tapping tools and date of tapping on <Emphasis Type="Italic">Acacia polyacantha</Emphasis> gum yield in South Kordofan State,Sudan

A study was conducted in South Kordofan, Sudan to determine the effect of tapping, tapping tools and date of tapping on the gum yield of Acacia polyacantha. A two-factor experiment was conducted for two seasons in 2008-2009. One location was used for two seasons and two locations for one season. The first factor (4 levels) was the tools of tapping: Makmak, Farrar, and Sonki, and the control which was not tapped. The second factor (2 levels) was the date of tapping that comprises mid October and mid November. These treatments were arranged in Randomaized Complete Block Design and replicated three times. Gum yield (g/tree and g/ picking) was recorded for five pickings. Economic analysis was done using the partial budget technique. The results showed highly significant (p < 0.01) differences on gum yield (g/picking and g/tree). The results indicated that the process of tapping increases gum production by 88.4% and 79.8% compared with un-tapped trees, respectively. The date of tapping has no significant effect on gum yield (g/tree and g/picking) of A. polyacantha. Tapping of the tree with Makmak in mid- November was found to be economically beneficial compared to using the other tools and the control. These results could identify a new source of income for the poor farmers in South Kordofan mainly because of the wild occurrence of Kakamut as a potential gum producing tree species grown naturally in the area.     

ALLEVIATION OF ALUMINUM IN ACIDIC SOILS AND ITS EFFECT ON GROWTH OF HYBRID AND CLONAL OIL PALM SEEDLINGS

Aluminum (Al) toxicity is an important factor in limiting crop production. The present study examined the Al alleviation effects on the growth of hybrid (breeding) and clonal (tissue culture) of D × P oil palm seedlings. The experiment was performed using calcium carbonate (CaCO₃), and ground magnesium limestone (GML) and magnesium carbonate (MgCO₃) as soil-amendments at different rates in Colombia and Malaysia, respectively. The effects of the treatments were evaluated monthly on vegetative variables and visual symptoms. Chlorophyll concentrations were recorded in Malaysia at the fifth month growing stage. The different amendments improved the soil fertility and it was reflected on better performance of shoot and root growth. The chlorophyll content in the frond number 3 for both materials enhanced significantly when Al saturation was low (0–30%). The results from the experiment revealed the importance of neutralization of Al in reducing its toxicity in oil palm.     

Nitrogen Fixation and N-Balance Studies on Bambara Groundnut (Vigna subterranea L. Verdc) Landraces Grown on Tropical Acidic Soils of Malaysia

Bambara groundnut has great potential as an alternative crop for improving food security in its production regions and beyond. A field experiment was conducted at the Field Research Centre of the Crops for the Future to obtain information on the nitrogen (N) fixation and N balance of Bambara groundnut landraces on tropical acidic soils of Malaysia. Treatments consisted of three Bambara groundnut landraces (Ex-Sokoto, Kaaro, and NN-1) laid out in a randomized complete block design replicated three times. Results obtained revealed that Ex-Sokoto landrace was greater in yield and N fixation, whereas N balance (-haulm) was greater in NN-1 landrace. The results revealed grain yield of 703–2256 kg ha^?1 and N fixation from 32–81 kg ha^?1 and suggest that Bambara groundnut could be integrated into a cereal-based cropping system. Ex-Sokoto landrace appeared to be the most promising for yield and N fixation under Malaysian acidic soil conditions.     

Glabrene and isoliquiritigenin as tyrosinase inhibitors from licorice roots

Tyrosinase is known to be a key enzyme in melanin biosynthesis, involved in determining the color of mammalian skin and hair. Various dermatological disorders, such as melasama, age spots, and sites of actinic damage, arise from the accumulation of an excessive level of epidermal pigmentation. The inadequacy of current therapies to treat these conditions as well as high cytotoxicity and mutagenicity, poor skin penetration, and low stability of formulations led us to seek new whitening agents to meet the medical requirements for depigmenting agents. The inhibitory effect of licorice extract on tyrosinase activity was higher than that expected from the level of glabridin in the extract. This led us to test for other components that may contribute to this strong inhibitory activity. Results indicated that glabrene and isoliquiritigenin (2',4',4-trihydroxychalcone) in the licorice extract can inhibit both mono- and diphenolase tyrosinase activities. The IC(50) values for glabrene and isoliquiritigenin were 3.5 and 8.1 microM, respectively, when tyrosine was used as substrate. The effects of glabrene and isoliquiritigenin on tyrosinase activity were dose-dependent and correlated to their ability to inhibit melanin formation in melanocytes. This is the first study indicating that glabrene and isoliquiritigenin exert varying degrees of inhibition on tyrosinase-dependent melanin biosynthesis, suggesting that isoflavenes and chalcones may serve as candidates for skin-lightening agents.     

鸡Apo VLDLⅡ基因内含子Ⅰ的多态性研究

本研究根据鸡Apo VLDL-Ⅱ基因内含子Ⅰ的基因序列设计3对引物,分别采用PCR-RFLP、PCR-SSCP技术对文昌鸡、如皋黄鸡、丝羽乌骨鸡、安卡肉鸡及红色原鸡5个鸡种进行多态性研究。结果表明,鸡Apo VLDL-Ⅱ基因内含子Ⅰ存在4处突变,分别为:1950处G/A、2522处A/C、2705处A/C及2793处C/T。统计结果显示:安卡肉鸡基因型频率的分布与如皋黄鸡、红色原鸡存在显著差异,文昌鸡基因型频率的分布与乌骨鸡差异不显著,除安卡肉鸡外所有鸡种均处于Hardy-Weinberg平衡状态。     

Genetic variation at the alpha‐1‐fucosyltransferase (FUT1) gene in Asian wild boar and Chinese and Western commercial pig breeds

Escherichia coli F18 bacteria producing enterotoxins and/or shigatoxin (ETEC/STEC) are main pathogens that cause oedema disease and postweaning diarrhoea in piglets, and alpha‐1‐fucosyltransferase (FUT1) gene has been identified as a candidate gene for controlling the expression of ETEC F18 receptor. The genetic variations at nucleotide position 307 in open reading frame of FUT1 gene in one wild boar breed and 20 western commercial and Chinese native pig breeds were investigated by polymerase chain reaction–restriction fragment length polymorphism. The results showed that the genetic polymorphisms of the FUT1 locus were only detected in western pig breeds and the Chinese Taihu (including Meishan pig, Fengjing pig and Erhualian pig), Huai and Lingao pig breeds; only Duroc and Pietrain possessed the resistant AA genotype, while the wild boar and other Chinese pig breeds only presented the susceptible genotype GG. The results indicated that Chinese native pig breeds lack genetic factors providing resistance to ETEC F18 bacteria. The resistant allele to ETEC F18 might originate from European wild boar. It was inferred that oedema and postweaning diarrhoea caused by ETEC F18 have close relationship with the growth rate, which can explain why on the contrary Chinese native pig breeds have stronger resistance to oedema and postweaning diarrhoea in piglets compared with western pig breeds.