อัลคาไลด์โปรตีนเนสของแบคทีเรียที่แยกได้จากมูลค้างคาว

Thailand Research Fund (TRF

Application of a new red carotenoid pigment-producing bacterium, Enterobacter sp. P41, as feed supplement for chicken

In order to use purple non-sulfur bacteria as feed supplement in chicken industries, screening for red pigment-producing bacteria with proteinases was done using hen feces as a target. One isolate, P<sub>41</sub>, with the highest proteinases activity was selected for further studies. Based on the data of biochemical and 16S rDNA sequence analysis, it was identified as Enterobacter sp. P41. This strain produced 0.16 mg of β-carotene with red color per gram of cell dry weight. Addition of the dried cells of Enterobacter sp. P<sub>41</sub> to chicken feeds did significantly intensify the egg yolk color (p = 0.000). Moreover, addition of the dried cells at the amount of 0.45 mg per kg of feed significantly increased the rate of egg-laying (p = 0.029). These results suggest that the dried cells of Enterobacter sp. P<sub>41</sub> might be useful as feed supplement for hens or other avian.Key words: β-Carotene, Enterobacter sp., red carotenoid pigment, egg yolk, egg-laying rate, proteinase

The effect of edible film on properties and specific sensory attributes of a gac (Momordica cochinchinensis Spreng) aril product

Gac aril has high contents of beta-carotenoids, lycopene, lipid and oil. This study aimed to delay the degradation of phytochemicals and avoid rancidification in gac aril by wrapping it with bacterial cellulose (BC). Fully ripe gac fruit were randomly sampled. The gac aril was removed and pasteurized by steaming at 100oC for 10 min and kept in the dark at 8oC. All experiments were done in triplicate. The conditions of wrapping were optimized. The functional, nutritional, physical and chemical properties, and specific sensory attributes of the wrapped gac aril were investigated. The results revealed that the gac aril was neatly wrapped over by Rhodococcus sp. MI 2 only under static conditions. A 10% seed culture gave the highest wet weight and dry weight of BC. The cellulose wrapping of gac aril by Rhodococcus sp. MI 2 could delay the degradation of phytochemicals and avoid rancidification for at least 14 days. The unwrapped and wrapped gac aril showed almost the same nutritive values. The main drivers of liking of the wrapped gac aril product were appearance, color and sweetness. Therefore, BC could be applied as an edible film in food wrapping and it may protect food against oxidation

Emerging Rickettsioses of the Thai-Myanmar Border1

To investigate the presence of rickettsioses in rural residents of the central Thai-Myanmar border, we tested the blood of 46 patients with fever. Four patients had murine typhus, three patients had scrub typhus, and eight patients had spotted fever group rickettsioses, including the first case of Rickettsia felis infection reported in Asia

Rubrivivax benzoatilyticus sp.nov., an aromatic hydrocarbon-degrading purple betaproteobacterium

A brown-coloured bacterium was isolated from photoheterotrophic (benzoate) enrichments of flooded paddy soil from Andhra Pradesh, India. On the basis of 16S rRNA gene sequence analysis, strain JA2(T) was shown to belong to the class Betaproteobacteria, related to Rubrivivax gelatinosus (99 % sequence similarity). Cells of strain JA2(T) are Gram-negative, motile rods with monopolar single flagella. The strain contained bacteriochlorophyll a and most probably the carotenoids spirilloxanthin and sphaeroidene, but did not have internal membrane structures. Intact cells had absorption maxima at 378, 488, 520, 590, 802 and 884 nm. No growth factors were required. Strain JA2(T) grew on benzoate, 2-aminobenzoate (anthranilate), 4-aminobenzoate, 4-hydroxybenzoate, phthalate, phenylalanine, trans-cinnamate, benzamide, salicylate, cyclohexanone, cyclohexanol and cyclohexane-2-carboxylate as carbon sources and/or electron donors. The DNA G+C content was 74.9 mol%. Based on DNA-DNA hybridization studies, 16S rRNA gene sequence analysis and morphological and physiological characteristics, strain JA2(T) is different from representatives of other photosynthetic species of the Betaproteobacteria and was recognised as representing a novel species, for which the name Rubrivivax benzoatilyticus sp. nov. is proposed. The type strain is JA2(T) (=ATCC BAA-35(T)=JCM 13220(T)=MTCC 7087(T))

Candida albicans Possesses Sap7 as a Pepstatin A-Insensitive Secreted Aspartic Protease

BACKGROUND: Candida albicans, a commensal organism, is a part of the normal flora of healthy individuals. However, once the host immunity is compromised, C. albicans opportunistically causes recurrent superficial or fatal systemic candidiasis. Secreted aspartic proteases (Sap), encoded by 10 types of SAP genes, have been suggested to contribute to various virulence processes. Thus, it is important to elucidate their biochemical properties for better understanding of the molecular mechanisms that how Sap isozymes damage host tissues. METHODOLOGY/PRINCIPAL FINDINGS: The SAP7 gene was cloned from C. albicans SC5314 and heterogeneously produced by Pichia pastoris. Measurement of Sap7 proteolytic activity using the FRETS-25Ala library showed that Sap7 was a pepstatin A-insensitive protease. To understand why Sap7 was insensitive to pepstatin A, alanine substitution mutants of Sap7 were constructed. We found that M242A and T467A mutants had normal proteolytic activity and sensitivity to pepstatin A. M242 and T467 were located in close proximity to the entrance to an active site, and alanine substitution at these positions widened the entrance. Our results suggest that this alteration might allow increased accessibility of pepstatin A to the active site. This inference was supported by the observation that the T467A mutant has stronger proteolytic activity than the wild type. CONCLUSIONS/SIGNIFICANCE: We found that Sap7 was a pepstatin A-insensitive protease, and that M242 and T467 restricted the accessibility of pepstatin A to the active site. This finding will lead to the development of a novel protease inhibitor beyond pepstatin A. Such a novel inhibitor will be an important research tool as well as pharmaceutical agent for patients suffering from candidiasis

การต้านแบคทีเรียและ/หรือการผลิตโปรตีเนสของแบคทีเรียแลกติกแอซิดและแบคทีเรียชนิด purple nonsulfur ที่แยกได้จากมูลไก่ : รายงานวิจัยฉบับสมบูรณ์โครงการ

The National Research Council of Thailan