ABSTRACT
Iron and phosphorus (P) are the important micro- and macro-nutrient for microalgae growth, respectively. However, the effect of iron and P on microalgae growth in co-culture associating with the formation of dominate algae has not been investigated before. In the current study, Anabaene flos-aquae, Chlorella vulgaris and Melosira sp. were co-cultivated under the addition of different initial iron and P to reveal the effect of iron and phosphorus on the growth of microalgae. The results showed that the mean growth rate of A. flos-aquae, C. vulgaris and Melosira was 0.270, 0.261 and 0.062, respectively, indicating that the A. flos-aquae and C. vulgaris algae are liable to be the dominant algae while the growth of Melosira was restrained when co-cultured. The ratio of Fe to P has a significant impact on the growth of microalgae and could be regarded as an indicator of algae growth. Microalgae showed a much more obvious uptake of iron compared to that of P. The information obtained in the current study was useful for the forecast of water quality and the control of microalgae bloom.
Subject(s)
Iron/pharmacology , Microalgae/drug effects , Phosphorus/pharmacology , Chlorella vulgaris/drug effects , Chlorella vulgaris/growth & development , Coculture Techniques , Diatoms/drug effects , Diatoms/growth & development , Dolichospermum flos-aquae/drug effects , Dolichospermum flos-aquae/growth & development , Eutrophication/drug effects , Microalgae/growth & development , Nutrients/pharmacologyABSTRACT
AIM: To evaluate the association of glutathione S-transferases gene polymorphisms with the risk of gastric cancer, with reference to smoking and Helicobacter pylori infection. METHODS: We conducted a 1:1 matched case-control study with 410 gastric cancer cases and 410 cancer-free controls. Polymorphisms of GSTM1, GSTT1 and GSTP1 were determined using PCR-CTPP. RESULTS: The GSTM1 and GSTT1 null genotypes were significantly associated with the risk of gastric cancer after adjusting for potential confounding factors (OR=1.68, 95% CI=1.32-2.23 for null GSTM1, OR=1.73; 95% CI=1.24-2.13 for null GSTT1). The combination of null GSTM1 and null GSTT1 conferred an elevated risk (OR=2.54, 95% CI=1.55-3.39). However, no association was found for GSTP1 polymorphism The smoking modified the association of GSTM1 and GSTT1 null genotypes with the risk of gastric cancer. CONCLUSION: GSTM1 and GSTT1 null genotypes are associated with increased risk of gastric cancer, and smoking modifies the association.
