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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.