不同栽培方式对烤烟生长发育及产质的影响

连续２年研究了不同栽培方式对烤烟的生长发育、产量及品质的影响。结果表明，在试验的５种栽培方式中（平栽、垄栽、垄深栽、平栽一次培土成垄、平栽二次培土成垄），以平栽二次培土成垄效果最好。烟株生长健壮，根系发达，产量高，品质好，香吃味也较好。     

培养条件对红茶菌生长及抗菌作用的影响

通过对红茶菌液培养过程的测定 ,得出较佳培养时间为 5d。探讨了温度、p H、供氧、培养基组成 (茶叶、诱导物、氮、磷 )对红茶菌生长及抗菌作用的影响 ,得出较佳培养工艺 :5%蔗糖 3%红茶 0 .1 %KH2 PO4 0 .1 %( NH4 ) 2 SO4 ,p H自然、纱布封口静止、变温培养 5d。     

Inhibition of yeast growth in grape juice through removal of iron and other metals

Growth of microbial spoilage organisms requires an adequate supply of essential trace metals. Removal of iron and other metals from grape juice with chelating resins was studied with a view to obtaining microbiological stability without the addition of chemical preservatives. Several chelating resins were examined for their iron and other metal removal efficiencies. High affinity and selective removal of essential trace microbial nutrient metals was investigated for its effects on the growth of Saccharomyces cerevisiae in grape juice.
Iron removal from grape juice was studied in terms of removal kinetics and completeness. Iron removal was fast, and almost all of the iron was removed within 1  h. The chelating resins were able to easily remove the iron to a level below 5 p.p.b. in a batch process, and with a column process the iron concentration could be reduced to about 1 p.p.b. Other metals significantly removed by the resins in the treatment were Cu, Mn, Mg, Ca and Zn. Levels of Na and K were also significantly affected by the treatments.
Grape juice with an iron content below 3 p.p.b. could be prepared by using the chelating resins. Preliminary evaluation indicated that the growth of S. cerevisiae , a bottom wine yeast, was substantially inhibited in the treated grape juice. The inhibitory effect could be abolished by re-addition of the removed metals.     

优化絮凝复合菌在马铃薯淀粉废水中培养及资源化处理条件的研究

通过单因素和正交实验优化马铃薯淀粉废水中培养絮凝复合菌的最佳营养条件,并利用响应面法优化所培养的絮凝复合菌处理马铃薯淀粉废水的最佳工艺条件。实验结果表明,马铃薯淀粉废水培养絮凝复合菌的最优条件为乙醇1.5m L/100m L、NH4NO30.15g/100m L、KH2PO40.35g/100m L、p H7.0;利用上述培养的絮凝复合菌处理马铃薯淀粉废水得到最佳工艺条件为复合菌投加量1m L/100m L、Ca Cl2投加量2m L/100m L、搅拌速度187r/min,此条件下马铃薯淀粉废水的化学需氧量(COD)去除率实际值达到89.10%,可回收粗蛋白物质6.23g/L作为动物蛋白饲料添加剂。      

渍水对油菜苗期生长及养分吸收的影响

为了解渍水对油菜的影响和恢复期油菜养分的变化,采用盆栽试验,研究不同持续时间的渍水对油菜（Brassica napus L.）品种中双11号苗期生长及养分吸收的影响。结果表明,渍水对苗期生长的不利影响不仅在于渍水期间,还在于渍水后生长恢复所需的时间。随渍水时间延长,叶片氮（N）、磷（P）、钾（K）、铁（Fe）、锌（Zn）、铜（Cu）含量显著降低,锰（Mn）含量显著升高;根系N、Fe、Zn、Cu含量显著升高,P含量显著降低,Mn含量3d时显著升高之后显著降低,而K含量没有显著变化。渍水使土壤中硝态氮与铵态氮的比例显著降低;速效P含量显著降低;速效K和有效态Fe、Zn含量出现先升高后降低的波动;有效态Cu在渍水期间没有显著变化,渍水后显著降低。     

培养条件对金黄色葡萄球菌-大肠杆菌混合生物被膜的影响

以常见食源性致病菌金黄色葡萄球菌和大肠杆菌为研究对象,采用微孔板法对混合生物被膜形成过程中的不同影响因素进行了研究。结果表明：在25 ℃或30 ℃条件下,采用质量分数0.8%的胰酶大豆肉汤（TSB）或0.8%的脑心浸出液（BHI）培养基培养时,生物被膜形成量较高;添加适量的葡萄糖、乳糖、麦芽糖和蔗糖可提高混合生物被膜形成能力;培养基中NaCl质量分数＞8%时,混合生物被膜的生长明显受到抑制。     

污水处理生物脱氮除磷影响因素及对策的研究

生物脱氮除磷技术可以有效提高污水处理的工作效率,增强出水水质.生物脱氮除磷技术可增强脱氮除磷的实效性,具有专业性和复杂性,但对工艺流程、装置和操作方法的要求较高.本文对污水处理生物脱氮除磷的原理和影响因素进行分析,提出污水处理生物脱氮除磷的对策,为实践工作提供参考.     

Temperature effect on nitrogen removal performance and bacterial community in culture of marine anammox bacteria derived from sea-based waste disposal site

Anaerobic ammonium oxidation (anammox) bacteria have been detected in variety of marine environment in recent years, however, there have been only a few studies on their characteristics in the culture. The aim of this study is to reveal the effect of temperature on nitrogen removal ability and bacterial community in a culture of marine anammox bacteria (MAAOB). The MAAOB were cultured from the sediment of a sea-based waste disposal site at the North Port of Osaka Bay in Japan. The maximum nitrogen removal rate (NRR) was observed at 25°C in the MAAOB culture, and it decreased both at below 20°C and over 33°C. The activation energy of the MAAOB culture was calculated to be 54.6 kJ mol(-1) in the 5°C to 30°C range. No significant change in bacterial community according with temperature (5-37°C) was confirmed in the results of polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE). Meanwhile, a number of bacteria related to the oxidation-reduction reaction of sulfur were confirmed and it is speculated that they involved in the activity of MAAOB and nitrogen removal ability in the culture.     

Effect of pre-incubation conditions on growth and survival of Staphylococcus aureus in sliced cooked chicken breast

In this work, the effect of pre-incubation conditions (temperature: 10, 15, 37°C; pH 5.5, 6.5 and water activity, a(w): 0.997, 0.960) was evaluated on the subsequent growth, survival and enterotoxin production (SE) of Staphylococcus aureus in cooked chicken breast incubated at 10 and 20°C. Results showed the ability of S. aureus to survive at 10°C when pre-incubated at low a(w) (0.960) what could constitute a food risk if osmotic stressed cells of S. aureus which form biofilms survive on dried surfaces, and they are transferred to cooked meat products by cross-contamination. Regarding growth at 20°C, cells pre-incubated at pH 5.5 and a(w) 0.960 had a longer lag phase and a slower maximum growth rate. On the contrary, it was highlighted that pre-incubation at optimal conditions (37°C/pH 6.5/a(w) 0.997) produced a better adaptation and a faster growth in meat products what would lead to a higher SE production. These findings can support the adoption of management strategies and preventive measures in food industries leading to avoid growth and SE production in meat products.     

Effects of pre-bloom leaf removal on growth of berry tissues and must composition in two red Vitis vinifera L. cultivars

Background and Aims:  Little work has been conducted on the effects that summer pruning operations have on the relative growth of grapevine berry parts. Our paper studies whether pre-bloom leaf removal is able to modify the proportions of seed, skin and flesh in ripe grapevines berries and the related effects on must composition.
Methods and Results:  Pre-bloom defoliation (D) of the first six basal leaves on main shoots was applied to the field-grown cvs Barbera and Lambrusco salamino ( Vitis vinifera L.) in Italy's Po Valley and compared with non-defoliated controls. D showed reduced fruitset, hence yield per shoot, and concurrently improved must soluble solids and total anthocyanins in both cultivars as a likely result of increased leaf-to-fruit ratio (+3.4 cm²/g and +5.2 cm²/g for Barbera and Lambrusco, respectively) and improved relative skin mass (from 6.0 to 9.0% in Barbera and from 8.1 to 10.4% in Lambrusco). In both cultivars, skin and seed mass were highly correlated with total berry mass and changes in relative skin mass were generally not related to berry size.
Conclusions:  These results indicate that berry size per se is not the primary factor in determining final grape composition, which instead seems to depend upon factors differentially affecting the growth of the various berry components.
Significance of the Study:  Pre-bloom D induced a consistent, site and cultivar-independent increase in relative skin mass suggesting this effect being strongly physiologically regulated.     

Influence of starter culture ratios and warm room treatment on free fatty acid and amino acid in Swiss cheese

Quantification of water-soluble volatile free fatty acids (FFA) and free amino acids (FAA) was performed as a ripening index and an indirect measure of flavor development in Swiss-type cheeses. The objective of this research was to assess the effect of warm room treatment (WRT) and usage ratio of starter cultures, Streptococcus thermophilus and Lactobacillus helveticus vs. propionibacteria, on the concentration of FFA and FAA in pilot plant-scale Swiss cheese. A capillary gas chromatograph equipped with a flame ionization detector was used for the analysis of FFA in Swiss cheese. Free amino acids were analyzed by the Cd-ninhydrin method. Starter culture ratios did not affect development of FAA during the cheese ripening. However, duration of WRT had an effect on the concentration of FAA in the Swiss cheese. Free amino acids increased considerably during WRT. A continuous increase in FAA was shown during 70-d ripening time after WRT. The concentrations of C2:0 and C3:0 fatty acids were affected by starter culture ratios after 2-wk WRT, but these differences had mostly disappeared after 3-wk WRT. Similar concentrations of FFA and FAA reported in previous studies were developed in Swiss cheese with a 3-wk WRT and a 0.33:1 ratio of Streptococcus thermophilus and Lactobacillus helveticus to propionibacteria.     

Impact of increasing dietary energy level during the finishing period on growth performance,pork quality and fatty acid profile in heavy pigs

Sixty Duroc × (Landrace × Large White) gilts of 93.5 of body weight (BW) were used to investigate the effect of increasing dietary net energy content (2280, 2350, and 2420 kcal/kg) on growth performance and carcass, meat, and fat characteristics. Animals were intended for dry-cured ham production. Therefore, pigs were slaughtered at 130 kg BW and a minimum fat thickness at Gluteus medius muscle (m. GM) was required. No effect was detected on daily gain or energy intake but feed intake decreased and feed conversion ratio tended to improve as energy increased. Fat depth at m. GM was wider and the proportion of suitable carcasses tended to be greater when energy increased. The treatment had scarce effect on meat and fatty acids. We conclude that 2350 kcal of net energy per kg of feed would optimize the productive and quality responses in gilts when are intended for dry-cured ham production.     

Influence of sulfur and nitrogen supply on growth,nutrient status and concentration of benzyl‐isothiocyanate in cress (Lepidium sativum L.)

BACKGROUND: The supply of nitrogen (N) and sulfur (S) exerts an interactive effect on glucosinolate (GS) accumulation in Brassica vegetables, but the consequences for the concentration of isothiocyanates (ITCs), released after decomposition of GS by myrosinase, have rarely been investigated. In addition to their phytosanitary function GS have also been discussed as transient S reservoir. RESULTS: Cress (Lepidium sativum, L.) plants were cultivated with varied supply of N (0.5, 1.0 and 2.0 g pot^?1) and S (0, 0.05 and 0.2 g pot^?1). Concentrations of total N and S and hence the N/S ratio responded significantly, as did the concentrations of nitrate and sulfate. Concentrations of benzyl‐ITC, derived from glucotropaeolin (benzyl‐GS), ranged from 6.7 to almost 30 µmol (g dry matter)^?1 and were negatively affected by high N supply. For a given S supply the benzyl‐ITC concentration was inversely related to the N/S ratio, an indicator of the S nutritional status. CONCLUSION: The results do not support the view that GS act as a transient S reservoir. Rather, moderate N and adequate S supplies lead to increased concentrations of this pharmacologically important constituent of cress. Copyright © 2008 Society of Chemical Industry     

Dielectric barrier discharge cold atmospheric plasma: Influence of processing parameters on microbial inactivation in meat and meat products

Decontamination of meat is commonly practiced to get rid of or decrease the microbial presence on the meat surface. Dielectric barrier discharge cold atmospheric plasma (DBD-CAP) as innovative technology is a food microbial inactivation technique considered in high regard by food scientists and engineers in present times. However, cold atmospheric plasma application is at the experimental stage, due to lack of sufficient information on its mode of action in inactivating microbes, food shelf-life extensibility, whereas, the nutritional value of food is preserved. In this review, we have appraised recent work on DBD-CAP concerning the decontamination treatment of meat products, highlighting the processing value results on the efficacy of the DBD-CAP microbial inactivation technique. Also, the paper will review the configurations, proposed mechanisms, and chemistry of DBD-CAP. Satisfactory microbial inactivation was observed. In terms of DBD-CAP application on sensory evaluation, inferences from reviewed literature showed that DBD has no significant effect on meat color and tenderness, whereas in contrast, TBARS values of fresh and processed meat are affected. DBD seems economically efficient and environmentally sustainable.     

Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth,development and iodine uptake of lettuce grown in water culture

BACKGROUND: Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture. RESULTS: In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 µg iodine L^?1, applied as iodate (IO₃^?) or iodide (I^?), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I^? than with IO₃^?. Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 µg iodine kg^?1 total leaf fresh weight. CONCLUSION: Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I^? and IO₃^?. I^? was more effective than IO₃^?. Fifty grams of iodine‐biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults. Copyright © 2010 Society of Chemical Industry     

Short communication: The effects of offering a high or low plane of milk preweaning on insulin-like growth factor and insulin-like growth factor binding proteins in dairy heifer calves

Although positive effects on growth have been shown when calves are placed on high planes of nutrition, little information exists regarding the effect of this feeding strategy on insulin-like growth factor-1 (IGF-1), a hormone whose fundamental action is to stimulate growth, and its binding proteins during the preweaning period. The objective of this study was to characterize IGF-1 and insulin-like growth factor binding protein (IGFBP) concentrations in plasma during the pre- and immediate postweaning period, when calves were offered a high or low plane of whole milk. Twenty-six female Holstein calves were randomly assigned to either a high (HI; 10 L/d; n = 13) or low (LO; 5 L/d; n = 13) plane of milk following colostrum feeding at d 3 of life. Calves were fed their respective diet as whole milk until d 48 when a 10-d weaning transition began. During this transition, milk was reduced by 10% per day such that all calves received no milk on d 59 of life. Blood samples were collected bi-weekly to measure IGF-1 and IGFBP in plasma. Calves fed HI gained more body weight than calves fed LO during the preweaning period (d 1–48 of life; 0.90 vs. 0.65 kg/d); however, no differences in average daily gain or metabolizable energy intake during the weaning transition (d 48–58 of life) or postweaning period (d 59–70 of life) occurred. Concentrations of IGF-1 were higher in HI calves during the preweaning period, which was associated with high levels of IGFBP-3 at wk 5 and lower IGFBP-2 during each measured time point preweaning as compared with LO. Insulin-like growth factor binding protein-4 was lower in HI calves only during wk 1, and IGFBP-5 was not affected by the dietary treatment. Overall, offering a high plane of nutrition was associated with changes in plasma IGF-1 and IGFBP that would indicate greater growth and development preweaning but not necessarily postweaning.