生菜条生产的卫生学调查

目的 :了解生食的生菜条卫生质量 ,探索该类产品的卫生监督、监测管理方法。方法 :采取实验室检测并结合日常卫生监督。结果 :生菜加工前后比较 ,微生物含量大幅下降 ,菌落总数分别为 1.2× 10 6 cfu/ g和 6.3× 10 3cfu/ g,大肠菌群分别为 >110 0 MPN/ g和 <3 0 MPN/ g;亚硝酸盐含量降低 ,分别为 6.8mg/ kg和 3 .1mg/ kg。加工前后铅、汞含量无明显变化。结论 :科学种植、合理温控、减少腐败。

Purification and Photodynamic Bioactivity of Phycoerythrin and Phycocyanin from Porphyra yezoensis Ueda

Phycoerythrin and phycocyanin were purified from Porphyra yezoensis Ueda with their bioactivity determined in this study. Continuous precipitation with ammonium sulfate at different concentrations(10%, 20%, 40% and 50%) increased the purity(A564:A280) of phycoerythrin to 1.49, 3.92 fold of the raw extract(0.38) and the purity(A615:A280) of phycocyanin to 0.70, 3.33 fold of the raw extract(0.21). Two more times of chromatography with hydroxylapatites finally made the purity of phycoerythrin and phycocyanin reach 5.50, 14.47 fold of the raw extract, and 5.10, 24.29 fold of the raw extract, respectviely. The yield of high purity phycoerythrin and phycocyanin were 0.21% and 0.09% of dried P. yezoensis blade, respectively. The photodynamic cytotoxic experiment showed that both phycoerythrin and phycocyanin inhibited the growth of liver tumor cells significantly. It was found that 250 mg L-1 purified phycoerythrin and phycocyanin inhibited the growth of hepatocellular carcinoma cells 24 h after laser-irradiation by 80% and 59%, respectively, and 100 mg L-1 purified phycoerythrin and phycocyanin induced the apoptosis of 31.54% and 32.54% of the cells, respectively, 8 h after photodynamic therapy. Oue findings demonstrated that P. yezoensis can serve as photosensitizer(phycoerythrin and phycocyanin) producer.

Change Numbers of Microorganisms under Vegetable Cultures of Irrigated Soils of Subtropical Zone of Azerbaijan

Number of microorganisms of soils of subtropic zones in a vegetable-fodder and vegetable-bean crop rotations compared with permanent cultivation of these cultures has been studied. The results of the analyses have shown that character of change of number of the basic physiological groups of microorganisms （a bacteria, sporeforming bacteria, actinomysetes and microscopic fungies） depends not only on soil-ecological conditions but also on the kind and biological features of cultivated cultures. In soils of subtropical zones the greatest number of organisms using organic nitrogen in food was observed on alluvial meadow-forestry soils and yellowish-gley soils. Gray-brown soils are rich in actinomycetes in comparison with alluvial meadow-forestry soils, but meadow-serozem is rich in spore-forming bacteria forms. A number of microscopic fungi of the studied soils were the least. High intensity of processes of mineralization was marked in meadow-serozem soils, the least in alluvial meadow-forestry and yellowish-gley soils. Under permanent cultures the quantity of microorganisms was less, and factor of mineralization is higher above, than in crop rotation.

Farmers＇ Coping Mechanisms for Common Bean Production under Water-Logged Soil Conditions in Uganda-Rwanda Boarder Region

Common bean （Phaseolus vulgaris L.） is a staple food and income crop in eastern Africa, especially within the Uganda-Rwanda boarder region where it constitutes a major component of food security. Unfortunately, bush beans are severely affected by frequent water-logging which persists over a considerable period of the year. In spite of this, farmers have continued to cultivate bush bean though with miserable yields. The study aimed to identify farmers＇ indigenous coping mechanisms to the climatic predicament, as a foundation for nurturing and subsequently designing appropriate management strategies for improved bean production in the region. A household survey was conducted in Kisoro district, in a location representative of the ecological conditions of Uganda-Rwanda region. 96 respondents were selected randomly at village level from a list of 500 households provided by the extension workers. Data were collected using semi-structured interviews. Findings showed that farmers possess vital coping mechanisms including construction of ridges, fertiliser application and chemical control of pests and diseases to expedite plant growth, and construction of drainage channels. It is clear that farmers＇ indigenous coping mechanisms need further nurturing and refining to improve their performance in dealing with water-logging crisis in the region.

Identification and bioinformatics analysis of micro RNAs from the sporophyte and gametophyte of Pyropia haitanensis

Pyropia haitanensis(T.J.Chang et B.F.Zheng) N.Kikuchi et M.Miyata( Porphyra haitanensis) is an economically important genus that is cultured widely in China.P.haitanensis is cultured on a larger scale than Pyropia yezoensis,making up an important part of the total production of cultivated Pyropia in China.However,the majority of molecular mechanisms underlying the physiological processes of P.haitanensis remain unknown.P.haitanensis could utilize inorganic carbon and the sporophytes of P.haitanensis might possess a PCK-type C 4-like carbon-fixation pathway.To identify micro RNAs and their probable roles in sporophyte and gametophyte development,we constructed and sequenced small RNA libraries from sporophytes and gametophytes of P.haitanensis.Five micro RNAs were identified that shared no sequence homology with known micro RNAs.Our results indicated that P.haitanensis might posses a complex s RNA processing system in which the novel micro RNAs act as important regulators of the development of different generations of P.haitanensis.

Removal of Cypermethrin with Seaweed Gracilaria lemaneiformis

Abstract The removal of cypermethrin with a red macroalga, Gracilaria lemaneiformis, was studied under laboratory conditions. Results showed that the residue contents with G. lemaneiformis were significantly lower than those corresponding groups without the algal thalli after 96 h treatment. The removal rates decreased with increasing concentrations, which were about 50% without G. lemaneiformis after 96h exposure, and increased to 89%, 73%, and 66% in flasks with G. lemaneiformis at the concentrations of 10, 100, and 1000 gg L-1, respectively. The amount of biosorption （absorption and adsorption） by G. lemaneiformis increased with the increasing concentration and exposure time. Adsorption was the main process for the removal by G. lemaneiformis, which accounted for 75%-97% of the total biosorption. However, biosorption only contributed 0.5%-19.3% to the total losses of cypermethrin, which was more efficient under the low concentration. Natural losses contributed the largest portion of losses, which was over 65% in all treatments during the experiment. The unknown pathway of removal, which might be the bio-decomposed by microorganisms attaching the algal thalli, also contributed a lot to the total removal. The results suggested that cultivation of G. lemaneiformis could significantly remove cypermethrin, especially at low concentrations, and large-scale cultivation of G. lemaneiformis has considerable potential of biorestoration of eutrophic and cypermethrin-poUuted coastal sea areas.

Study on the Ability of Coriander Water Purification

In order to study on the water purification ability of coriander, according to the material of Iris pseudacorus, Pontederia cordata, Thalia dealbata, coriander, Lythrum salicaria as the research object, the paper carries on the analysis and comparison of water purification ability under greenhouse conditions in the 3~6 month period. The results showed： N, P content of coriander organizational changes before and after the test. Physiological responses of different plants, coriander is not sensitive to the physiological responses to stress of sewage, sewage adaptability is relatively strong. Judging from the effect of different plants to the water, then spent force has highest the removal rate for TN, coriander has the strongest absorption capacity for TP, water purification plant is excellent