微生物法去除H_2S的研究进展

通过对微生物去除H2S气体方法的介绍,综述了微生物除硫原理、工艺和技术,叙述了除H2S常用微生物(栖泥绿菌,化硫硫杆菌、排硫硫杆菌、氧化亚铁硫杆菌和脱氮硫杆菌)的性质及去硫原理,介绍了四种生物反应器(曝气式反应器、生物洗涤器、生物滤床和生物滴滤床)及其应用实例,为今后选择合适的除硫工艺提供参考。

关于档案有害微生物定义和种类探讨

三、档案有害微生物的种类及其分类隶属 恩格斯曾教导说:“没有种的概念,整个科学就没有了”。这正说明搞清楚档案有害微生物的种类对研究和防治工作的重要意义。因为一个正确的微生物名称往往伴随着很多文献资料,如果种类不明确,就很难利用这些资料,也就难以进行有针对性的研究和理想有效的防治工作。

Why bortezomib cannot go with ‘green'?

Eat more‘green’or eat‘five a day’is one of the most important healthy lifestyle behaviours in the 21 century.Aiming to fight cancer effectively,more than half patients use vitamins or herbs concurrently with conventional anticancer treatment.Flavonoids or polyphenols existing in vegetables,fruits and green tea are common plant pigments with antioxidant properties and considered acting as cancer preventing or anti-cancer agents.Recently it was found that some flavonoids and vitamin C in diet or supplements have antagonistic effect with the anti-cancer drug bortezomib.Bortezomib is a specific inhibitor for proteasome and is currently used for treatment of relapsed and refractory multiple myeloma.Despite its successful rates in treating multiple myeloma and other solid tumors,it is unable to kill leukemic cells in the blood.It was recently revealed that some flavonoids and vitamin C present in green leaves and green teas in the blood can neutralize bortezomib by directly interaction between two chemicals.Here we summarize why dietary flavonoids should be avoided in patients who take bortezomib as chemotherapeutic drug.

Lipid enhancement in microalgae by temporal phase separation:Use of indigenous sources of nutrients

Microalgae have been recommended as superior candidate for fuel production because of their advantages of higher photosynthetic efficiency, biomass & lipid productivity, and faster growth rate as compared to other energy crops. To meet up all these criteria, we have developed a continuous outdoor micro-algal raceway pond reactor(RPR) and a lab scale indoor tubular photo bioreactor(PBR) for biofuel production. An attempt to utilise indigenous sources of nutrients to improve the economics also revealed that micro-algal culturing can also be used as a mode of nutrient removal and water treatment. The photosynthetic rate and lipid production were enhanced by arresting daytime cell division and promoting night-time cell division. A 50% lipid improvement was observed for the particular algal consortia. Microscopic studies revealed that temporal phase separation could be achieved by adjusting nutrient distribution pattern. To monitor temporal phase separation, it is required to know DNA multiplication model. Quantification of g DNA in RPR confirmed that cell division happens during the night which positively affects the photosynthetic efficiency and lipid productivity of microalgae.

Performance and Ruminal Characteristics of Beef Cattle Fed Four Different Hybrids Sorghum Silages

This study was conducted to evaluate the intake, total and partial digestibility of nutrient, ruminal pH and ammonia concentration, microbial protein synthesis and performance in crossbred Holstein × Zebu cattle fed four different hybrids sorghum silages （1F305, XBF60329, BRS610, Volumax）. In Experiment 1, four rumen and abomasum fistulated steers, 400 ± 80 kg, distributed in a 4 × 4 Latin Square, were used. In Experiment 2, 28 crossbred Holstein × Zebu steers, 350 ± 50 kg, distributed in a randomized block design with four treatments and seven replicates, were used. In Experiment 1, it was observed that nutrient intake, as well as total, ruminal and intestinal digestibility of nutrient, were not affected （P 〉 0.05） by diets, except for total apparent digestibility of neutral detergent fiber （NDFap）, which was lower for the BRS610 hybrid. There was lower NDFap ingestion in animals that received a diet containing silage from the BRS610 hybrid, however, the lowest intake non-fibrous carbohydrates （NFC） was observed for the diet containing silage from the Volumax hybrid. In Experiment 2, nutrient intake were not affected by the diets （P 〉 0.05）, whereas, NDFap intake was lesser for hybrid BRS610. It was found that daily weight gain and feed conversion were not affected by different silages diets. Therefore, it may be concluded that the diets used were nutritionally equivalent, as they promoted similar animal performance without affecting ruminal parameters.

Cardiotrophin-1 promotes cardiomyocyte differentiation from mouse induced pluripotent stem cells via JAK2/STAT3/Pim-1 signaling pathway

Background The induced pluripotent stem cell （iPSC） has shown great potential in cellular therapy of myocardial infarction （MI）, while its application is hampered by the low efficiency of cardiomyocyte differentiation. The present study was designed to investigate the effects of cardiotrophin-1 （CT-1） on cardiomyocyte differentiation from mouse induced pluripotent stem cells （miPSCs） and the underlying mechanisms involved. Methods The optimal treatment condition for cardiomyocyte differentiation from miPSCs was established with ideal concentration （10 ng/mL） and duration （from day 3 to day 14） of CT-1 administration. Up-regulated expression of cardiac specific genes that accounted for embryonic cardiogenesis was observed by quantitative RT-PCR. Elevated amount of a-myosin heavy chain （ct-MHC） and cardiac troponin I （cTn I） positive cells were detected by immunofluorescence staining and flow cytometry analysis in CT- 1 group. Results Transmission electron microscopic analysis revealed that cells treated with CT- 1 showed better organized sacromeric structure and more mitochondria, which are morphological characteristic of matured cardiomyocytes. Western blot demonstrated that CT-1 promotes cardiomyocyte differentiation from miPSCs partly via JAK2/STAT3/Pim-1 pathway as compared with control group. Conclusions These findings suggested that CT-1 could enhance the cardiomyocyte differentiation as well as the maturation of mouse induced pluripotent stem cell derived cardiomyocytes by regulating JAK2/STAT3/Pim-1 signaling pathway.

Effect of Concentrate to Roughage Ratio on Cost Effective Growth Performance of Brahman Crossbred Calves

An experiment was conducted to evaluate the growth performance and cost per gain of Brahman × local crossbred bull calves receiving three diets with varying concentrate to roughage ratio （C：R） of 75：25, 65：35 and 55：45 on dry matter （DM） basis. Twelve bull calves （aging 11.5 ±1.2 months and 170.8 ± 13.0 kg live weight） divided into three equal groups were fed on three diets. The diets were balanced to 14.5% crude protein （CP） level and 10.5 MJ metabolizable energy （ME） per kg DM, formulating different concentrate mixtures. German grass （Echinoclora grousgali） and paddy straw were offered at 2：1 ratio on DM basis as roughages. The results revealed that C：R ratio did not affect （P 〉 0.05） the intake of feed and nutrients, feed efficiency （7.04, 6.94 and 6.76） and average daily gain （981,958 and 976 g）. Digestibility of nutrients was not affected （P 〉 0.05） by C：R. Animals fed diet with C：R = 55：45 had the lowest feed cost （Bangladeshi Taka 136.8 BDT/kg live weight gain）, which was increased （147.5 B DT and 153.8 BDT） non-significantly （P 〉 0.05） with the increasing level of concentrate. The diet consisting of 55% concentrate mixture showed similar results with the diet consisting of 75% concentrate mixture, but was comparatively economic. Therefore, considering the growth performance and cost per kg gain of Brahman crossbred growing calves, it may be concluded that the diet consisting of 55：45 C：R may be used for economic beef production.

Spacial Distribution Characteristics, Activity and Degradation Capability of the Biofilm in Integrated Vertical-flow Constructed Wetland

The spacial distribution characteristics, activity and degradation capability of the biofilm in integrated vertical-flow constructed wetland were investigated. Results showed that the biofilm widely distributed in the substrate of integrated vertical-flow constructed wetland and mainly in the 0-10 cm top layer where the activity ofdehydrogenase of the biofilm was also higher than that of other layers. The water quality could also affect the activity of the biofilm, for the TF（1,3,5-Triphenylformazan） amount reduced by the biofim incubated in water of the higher eutrophication was larger, too. The PCP （pentachlorophenol） removal rate by the substrate with biofilm was 1.5 times that without biofilm. In total, the biofilm of the down-flow chamber appeared larger biomass, higher dehydrogenase activity and stronger degradation capability of organic contamination than that in up-flow chamber and it was the major place for removal of the organic matters in waste water.

Chemical and Functional Properties of Full Fat and Defatted White Melon （Cucumeropsis mannii） Seed Flours

Cucumeropsis mannii, an underutilized oil seed was processed into raw full fat and defatted seed flours and its chemical, functional properties and anti-nutritional factors were determined using standard techniques. The effects of sample concentration and pH on the foaming properties of the seed flours were determined. The results showed that the full fat and defatted seed flours contained the following in g/100 g sample; 5.0 and 5.1; 45.8 and 1.0; 39.4 and 78.7; 3.45 and 4.40; 1.50 and 3.05; 4.85 and 7.75 for moisture, crude fat, protein, ash, crude fibre and carbohydrate, respectively. The most abundant mineral elements in the seed flour （mg/100 g） are potassium （198.5）, followed by nickel （30.0） and magnesium （28.4）. The water absorption capacity, oil absorption capacity, foaming capacity and stability, least gelation concentration, emulsion capacity and bulk density are 55.5% and 125.0%; 128.8% and 184.0%; 10.5% and 17.0%; 3.0% and 1.5%; 16.0% and 10.0 g/mL; 85.0 and 115.0 mL/g; 0.42 and 0.25 g/mL, respectively. Defatting influenced the functional properties. The foaming capacity is dependent on sample concentration and pH. The protein solubility of the full fat and defatted seed flours was minimum between pH 3 and 4 and maximum at pH 11. The anti-nutritional composition of the seed flour revealed the following： tannic acid, 1.54 mg/100 g; phytin phosphorus, 0.70 rag/g; phytic acid, 2.48 mg/g; oxalate, 1.85 mg/g; alkaloids 1.97% and saponin 0.50%. The seed flours （full fat and defatted） have potential as nutrient supplement, thickeners and emulsifiers in food system.

干旱区土壤自养微生物研究进展

微生物自养固碳是维持干旱区土壤微生物群落结构及异养活动的重要过程,并影响地表生物结皮的演替及生态功能。近年来,土壤微生物组学的广泛应用,拓展了蓝细菌及真核藻类土壤自养微生物功能群研究,揭示了非蓝细菌类原核微生物向土壤输入有机质的可能。基于此,本文综述了干旱区土壤蓝细菌及藻类的分布及功能特征,并总结了环境因子的调控作用,重点总结了近几年对非蓝细菌自养微生物功能群及其生态功能的探索,最后对干旱区土壤自养微生物功能群研究的发展进行了总结与展望,以期为深入理解干旱区土壤微生物群落的形成及发展机理提供理论基础,并为良好生物结皮的构建提供科学依据。

Effect of three cooking methods on nutrient components and antioxidant capacities of bamboo shoot(Phyllostachys praecox C.D. Chu et C.S. Chao)

Three cooking methods,namely boiling,steaming,and stir-frying for 5 to 10 min,were used to evaluate the effect on nutrient components,free amino acids,L-ascorbic acid,total phenolic contents,and antioxidant capacities of bamboo shoots(Phyllostachys praecox).Results showed that boiling and stir-frying had a great effect on the nutrient components and they decreased the contents of protein,soluble sugar,and ash,and caused a great loss in the total free amino acids(decreased by 38.35% and 34.86%,respectively).Significant differences(P<0.05) in free amino acids were observed in the samples cooked by different methods.Stir-fried bamboo shoots had a high fat content which increased by 528.57% because of the addition of edible oil.After boiling,the L-ascorbic acid and total phenolic contents were significantly reduced,while steaming increased total phenolic content by 3.98% and stir-frying well-preserved L-ascorbic acid(78.87% of its previous content).Results of the antioxidative property study showed that stir-frying could increase antioxidant capacities of bamboo shoots.It is concluded that stir-frying is more suitable for bamboo shoots because it could obtain the maximum retention of antioxidant capacities.

Cyanobacterial bloom affects structural and functional succession of microbial communities in urban wetland sediments in the Qinghai Plateau

Algal blooms significantly affect microbial communities in wetland ecosystems.However,little is known about the succession of sediment microbial communities during algal blooms.This study aimed to investigate the temporal patterns of sediment bacterial community structure and function succession during algal blooms(March to May 2022)with high-throughput sequencing technology.To this end,algal blooms were divided into the bloom stage(BS),decomposition stage(DS)and end stage(ES).The results showed that:(i)The algal blooms were dominated by Microcystis species within Cyanobacteria.Both phytoplankton abundance and biomass reached the peak in the BS,with 45.78×105 cells/L and 5.97 mg/L,respectively.(ii)The alpha diversity indices of the sediment bacterial community showed a monotonically increasing trend,with the lowest value in the BS.Cyanobacterial blooms reduced the relative abundance of Actinobacteria and Chloroflexi,and raised that of Firmicutes,Proteobacteria and Bacteroidetes.(iii)Cyanobacterial blooms remarkably decreased the complexity of the co-occurrence network of the sediment bacterial community,which resisted extreme environmental conditions in the BS and DS by increasing positive relationships.(iv)Mantel test showed that phytoplankton biomass,T,dissolved oxygen and organic carbon had significant effects on the sediment bacterial community.The results of this study are important for the ecological management of algal blooms through microorganisms.