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The production of inexpensive chitinolytic enzymes is an element in the utilization of shellfish-processing waste. In this study, shrimp and crab shell powder, prepared by treating shrimp-and crab-processing waste by boiling and crushing, was used as a substrate for the isolation of an antifungal chitinase-producing microorganism. Bacillus subtilis NPU 001, a strain isolated from soil samples, excreted a chitinase when cultured in a medium containing 2% (w/v) shrimp and crab shell powder as the major carbon source. The chitinase, which was purified by sequential chromatography, had a Mw of 31 kDa and a pI of 5.4. The purified chitinase (2 mg ml -1 ) inhibited hyphal extension of the fungus Fusarium oxysporum. Compared with other known bacterial chitinases, the unique characteristics of NPU 001 chitinase include antifungal activity against plant-pathogenic fungi and the production of chitotriose as the major enzymatic hydrolysate from colloidal chitin.

Hemolysin BL (HBL) is a major virulence factor for Bacillus cereus group strains. It is also a target enterotoxin for the most commonly used B. cereus detection kit, i.e., the B. cereus enterotoxin (diarrheal type) reversed passive latex agglutination (BCET-RPLA) test kit. A survey of the HBL activities and the cytotoxicities to the Chinese hamster ovary (CHO) cells for the B. cereus group strains, however, showed that although only part of the B. cereus group strains are HBL active, all strains show cytotoxicity to the CHO cells. Thus, methods that allow the detection of not only the HBL but also of the B. cereus group strains are important. In this study, by comparison of the gene sequences of the 16S rRNA for B. cereus group and other bacteria strains, we designed primers B16S1 and B16S2 specific to all the B. cereus group strains. In addition, because HBL is a major enterotoxin, we also designed HBL gene-specific polymerase chain reaction (PCR) primers, i.e., Hm1 and Hm2, that generated the same results as those of the hemolysis and BCET-RPLA assays. Primers B16S1/B16S2 and Hm1/Hm2 could be combined into a multiplex PCR system for the simultaneous detection of B. cereus group cells and the possible presence of their HBL enterotoxins. Also, all these PCR systems allowed the detection of n x 10(0) CFU B. cereus cells per g of food sample if an 8-h enrichment step was performed prior to the PCR.

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Background: Zhulingtang (ZLT), a traditional Chinese medicine formula, was used to evaluate the antilithic effects of experimentally induced calcium oxalate (CaOx) nephrolithiasis in ethylene glycol (EG)-fed rats. Materials and Methods: A total of 35 male Sprague-Dawley rats were randomly divided into 4 groups. Rats in group 1 (n = 8) served as the normal control. Rats in group 2 (n = 11) were treated with gastric gavages of starch as placebo and 0.75% EG as a stone inducer. Rats in group 3 (n = 8) were given 0.75% EG and a low dose (305 mg/kg) of ZLT. Rats in group 4 (n = 8) were treated with EG and a high dose (915 mg/kg) of ZLT. Twenty-four-hour urine and blood samples were collected at the beginning and at the end of the experiment for biochemical analysis. The histological appearances of the kidneys were observed under a polarized light microscope, and the crystal deposits were evaluated by a semiquantitative scoring method, computer assisted with ImageScoring software. Results: Our results revealed that rats fed with 0.75% EG for 4 weeks successfully produced renal deposition of CaOx. The severities of crystal deposition were significantly reduced in the 2 ZLT-fed groups compared with the placebo group (p = 0.025 and 0.047, respectively). Rats in the low-dose ZLT and placebo groups exhibited significantly lower serum phosphorus in comparison with the control rats (p = 0.005 and 0.03, respectively). Rats of the placebo group (EG + starch) encountered growth retardation, with their body weights slowly increasing, expressed as 160.63 ± 23.06 g, compared with 179.63 ± 13.41 g in normal rats (p < 0.001). Conclusion: ZLT reduced the severity of CaOx crystallization and slowed down the body weight loss effects. Therefore, the traditional Chinese medicine herbal formula ZLT may be an effective reagent for renal stone prophylaxis. Although the mechanism of ZLT in crystal inhibition remains unclear, macromolecules may be involved.

Due to the sweeping influence of capitalism, most food processing is now done through standardized production workflows in order to quickly replicate and churn out a large quantity of products. This has led to an increasing number of homogenized and delocalized products flooding the market and a disconnection between consumers and local food producers. Penghu outlying island is rich in unique local agricultural products but seriously lacks brand images and channel strategies, as manifested in an unstable demand and supply, a high degree of homogeneity (in products) and the majority of farmers producing and selling their products autonomously. This study applies the local food system and actor-network theory as the basis of theoretical frameworks as well as agricultural practices in Penghu as the research object. We used field investigation, in-depth interview and the means-end chain method to examine important contextual factors' influence on the local agricultural food system, important actors and challenges and key influential factors for local brand value that affect the development of the local agricultural food system in Penghu outlying island. The actor-network perceptual map of local brand value proposed in this study can help agricultural practitioners when making decisions and can formulate strategies for their products to increase the product visibility and recognition. This perceptual map can also facilitate the expansion of the target customers and channel distributions suitable for individual agricultural products. Our study presents the following recommendations: increase the manpower of agricultural practices through the working holiday approach; local government should provide support enabling agriculture producers to gain professional knowledge in marketing; and agriculture producers should form cooperatives which focus on the unique local agricultural products that are produced and marketed locally in Penghu.

The effects of high hydrostatic pressure (HHP) treatments on histamine-forming bacteria (HFB) Morganella morganii and Photobacterium phosphoreum in phosphate buffer and tuna meat slurry were investigated using viability counting and scanning electron microscopy. The first-order model fits the destruction kinetics of high pressure on M. morganii and P. phosphoreum during the pressure hold period. The D-values of M. morganii (200 to 600 MPa) and P. phosphoreum (100 to 400 MPa) in phosphate buffer ranged from 16.4 to 0.08 min and 26.4 to 0.19 min, respectively, whereas those in tuna meat slurry ranged from 51.0 to 0.09 min and 71.6 to 0.19 min, respectively. M. morganii had higher D-values than P. phosphoreum at the same pressure, indicating it was more resistant to HHP treatment. HFB had a higher D-value in tuna meat slurry compared with that in phosphate buffer, indicating that the HFB were more resistant to pressure in tuna meat slurry. The Zp values (pressure range that results in a 10-fold change in D-value) of M. morganii and P. phosphoreum were 162 and 140 MPa in phosphate buffer and 153 and 105 MPa in tuna meat slurry, respectively. Damage to the cell wall and cell membrane by HHP treatments can be observed by scanning electron microscopy. To our knowledge, this is the first report to demonstrate that HHP can be applied to inactivate the HFB M. morganii and P. phosphoreum by inducing morphological changes in the cells. HIGHLIGHTS

The use of Bacillus thuringiensis (Bt) strains with high insecticidal activity is essential for the preparation of bioinsecticide. In this study, for 60 Bt strains isolated in Taiwan, their genotypes and the correlation of some cry genes as well as the expression levels of cry1 genes, with their insecticidal activities against Plutella xylostella, were investigated. Pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) results revealed that the genotypes of these Bt strains are highly diversified. Also, a considerable number of the Bt strains isolated in Taiwan were found to have high insecticidal activities. Since strains that showed individual combined patterns of PFGE and RAPD exhibited distinct insecticidal activities against P. xylostella, thus, these genotypes may be useful for the identification of the new Bt strains and those which have been used in bioinsecticides. In addition, although the presence of cry2Aa1 may have a greater effect on the insecticidal activity of Bt strains in bioassay than other cry genes, only high expression level of cry1 genes plays a key role to determine the insecticidal activity of Bt strains. In conclusion, both RAPD and PFGE are effective in the differentiation of Bt strains. The presence of cry2Aa1 and, especially, the expression level of cry1 genes are useful for the prediction of the insecticidal activities of Bt strains against P. xylostella.