Research Progress on the Development and Application of New Natural Tobacco Humectants

The research progress on the development and application of new natural tobacco humectants was reviewed in the paper.Plants,animals and microbes contain special moisturizing substances,showing distinctive advantages and outstanding effects in respect of the tobacco moisture content maintaining and cigarette suction comfort promoting.The development necessity,major types,functional mechanism and influence on cigarette quality of new natural tobacco humectants development were compared and elaborated.Additionally,the prospect of new natural tobacco humectants development and application was forecasted.

Comparison of bioleaching of chalcopyrite concentrates with mixed culture after cryopreservation with PEG-2000 in liquid nitrogen

A mixed culture of bioleaching microorganisms was enriched.Then the mixed culture was preserved by liquid nitrogen cryopreservation for 6 months and 12 months,respectively,using PEG-2000 as the protective agent.The chalcopyrite leaching ability,activity and diversity of the mixed culture before and after preservation were compared.The results showed that the copper extraction rate was 95.7%in chalcopyrite bioleaching within 20 d by the original culture.After cryopreservation for 6 months and 12 months,the copper extraction rate of the mixed culture was 94.9%within 25 d and 93.6%within 35 d,respectively.The cell viability achieved 87%and 41%after being preserved for 6 months and 12 months,respectively.Furthermore,the ecology analysis identified Acidithiobacillus ferrooxidans,Acidithiobacillus caldus,Sulfobacillus thermotolerans and Pseudomonas aeruginosa in the original mixed culture.After cryopreservation for 12 months,the composition of community changed,but the predominant microorganisms still existed.

Effects of Land Management Practices on Labile Organic Carbon Fractions in Rice Cultivation

A research trial with four land management practices, i.e., traditional tillage-fallow (TTF), traditional tillage-wheat (TTW), conservation tillage-fallow (CTF) and conservation tillage-wheat (CTW), was sampled in the 15th year after its establishment to assess the effects of different management practices on labile organic carbon fractions (LOCFs), such as easily oxidizable organic carbon (EOC), dissolved organic carbon (DOC), particulate organic carbon (POC) and microbial biomass carbon (MBC) in a typical paddy soil, Chongqing, Southwest China. The results indicated that LOCFs were significantly influenced by the combination of no-tillage, ridge culture and crop rotation. And, different combination patterns showed different effectiveness on soil LOCFs. The effects of no-tillage, ridge culture and wheat cultivation on EOC, DOC, POC and MBC mainly happened at 0-10cm. At this depth, soil under CTW had higher EOC, DOC, POC and MBC contents, compared to TTF, TTW and CTF, respectively. Moreover, the contents of LOCFs for different practices generally decreased when the soil depth increased. Our findings suggest that the paddy soil in Southwest China could be managed to concentrate greater quantities of EOC, DOC, POC and MBC.

Microbiota of Fossil Animals Preserved in Yakut Permafrost

Microbiological investigation of the fossil animals preserved in permafrost represents obvious interest for science. Lack of data in this sphere gives even greater importance to any findings giving us opportunity to learn more about remote past of microorganisms. In this respect, preserved remains of fossil are considered as unique biological materials for scientific investigations. Bacillus bacteria strains isolated from the paleomicrobiota of mammoth fauna are not only have high durability （20-30 thousand of years） in permafrost, but are still able to produce biologically active substances. Strains of bacteria of the genus Bacillus, isolated from the tissues of the representatives of the mammoth fauna have strong antagonistic properties to hemolytic streptococci--Streptococcus equi, pathogenic for animals--Salmonella abortus equi, also toxigenic micromycetes genera Aspergillus, Alternuria, Penicillum and fungal pathogens of plant diseases--Botrytis cimeria and Fuzarium oxysporium. The strains of bacteria of the genus Bacillus are not pathogenic to plants and animals, but initially resistant to wide range of antibiotics. Dominance strains of Bacillus bacteria, producing strong bacteriocins in the soft tissues of fossil animals, contributing to their long cryo bio conservation. In addition, bacterial strains of Bacillus subtilis, isolated from paleo microbiota have strong oxidizing properties. Microbiota of fossils preserved in permafrost of Yakutia is of particular interest for microbiology and modem biotechnology.

Security evaluation of compounded microbial flocculant

A new kind of compounded microbial flocculant (CMBF) for water and wastewater treatment has been developed through biological technology. In order to discuss its biological security, four groups of experiments, rat acute toxicity test via mouth, salmonella assay in vitro, mouse micronucleus in vivo test and teratogenesis test were conducted to evaluate its general toxicity, genotoxicity and generative toxicity. The experimental results showed that this type of compounded microbial flocculant was a substantial non-toxic substance based on the fact that LD50 value was over 10 mg/kg. The results from salmonella in vivo test and mouse micronucleus in vivo test revealed that the compounded microbial flocculant is a genetically non-toxic substance. Furthermore, compounded microbial flocculant has little effect on the growth of all the rats, and any morphologic abnormal phenomenon hasn’t appeared.

Relation between Mesophilic and Psychrotrophic Aerobic Sporulating Microorganisms in Milk

The occurrence and the detection system of mesophilic and psychrotrophic aerobic sporulating microorganisms （MPAS） in raw cow＇s milk were studied. Samples of raw cow＇s bulk tank milk were taken 21 times in 14 farms during one year. Basis of the method for MPAS assessment is the milk sample inactivation at the temperature 80-82 ℃ for 30 minutes followed by incubation in cultivation dishes at 30 -4- 1 ℃ for 3 days-mesophilic aerobic sporulates （MAS）, and at 6.5 .4- 1 ℃ for 10 days-psychrotrophic aerobic sporulates （PAS）. The total count of MPAS was within the span 2.5-340 CFU/mL （colony forming units）. Average plate count of MPAS was 59.4 CFU/mL with variation coefficient 93.1%. MPAS count found in the same dishes at incubation for mesophilic and subsequently strictly psychrophilic microorganisms （MAS ＋ SPAS） which enables to exclude overestimation of results by sporulates able to grow at both incubation temperatures was on average 56.9 CFU/mL what represents 95.8% out of the number of sums of individual dishes at two temperatures （MAS ＋ PAS）. Correlation coefficient of these two types of results r = 0.99 gives evidence of close dependence that is expressed by linear regression equation y = 0.9773x. We can consider the method using at first 30 .4- 1 ℃ and subsequently 6.5 -4-1℃ （MAS ＋ SPAS） as more correct than the method with the opposite order of cultivation temperatures because of better regression coefficient of linear dependence and higher correlation coefficient in relation to the sum of independent incubations （MAS ＋ PAS）.

Borderline Products between Bio-fertilizers/ Bio-effectors and Plant Protectants： The Role of Microbial Consortia

In the delicate normative balance, at European Union （EU） level of the borderline products （i.e., between plant protectants and bio-fertilizers/bio-effectors） containing microbial consortia （MC） instead of single microbial strains, the most relevant factors influencing the categorization of the products are the intention of use, the cell density and the mode of action. For the latter, the basic difference between the two types of products is that a plant protectant has a targeted activity on plant pathogens, while a bio-fertilizer acts indirectly by nourishing and fortifying the host plant （healthier plant）, thus inducing a generalized resistance to the onset of pathological status, irrespective of its origin and nature. Case-studies are presented on the effectiveness of MC as bio-fertilizers/bio-effectors on different crops. Bio-fertilizers exhibit a double effect--biotic and abiotic, leading to the fortification of the crop plant linked to its more effective water and nutrient uptakes as well asto a generalized healthier status. This in turn leads to a higher resistance to diseases. In addition, bio-fertilizers play a relevant role on the reduction of environmental impacts due to chemical fertilizers, e.g., by facilitating the uptake of phosphorus （P）, thus reducing the need of P fertilization. Although finding a scientifically-based balance between regulatory need and marketing constraint is not always an easy task, the availability of scientific advancements combined to common sense should help in describing positive effects and risk profiles of MC in agriculture.

科技传真

日研制出能将垃圾变土壤改良剂的设备 日本森田特机公司研制出能使垃圾变为土壤改良剂的生产设备,并即将投放市场。 这种垃圾处理设备长2.45米,宽1.30米,高1.53米。这种设备,能将生活垃圾和从土壤中提取的数种微生物用计算机来控制里面的温度、湿度和酶等,以使微生物保持最佳活性状态,对垃圾进行分解。 据该公司介绍,这种设备先用加热器将温度升高至60℃,然后通过设备内的旋转装置提供酶,制造使微生物活跃的环境,并将垃圾进行干燥和分解,使其重量降至原来的1/6,最后用热风将温度升高到200℃,并制成完全没有水分的粉状。整个处理过程约需48小时。该设备配有脱臭装置,臭味不会外泄。

Symbionts, a promising source of bioactive natural products

Symbionts are microorganisms residing in multicellular hosts(e.g., plants and animals), and they have been witnessed to be a rich source of diverse functional molecules. This review describes structures and biological activities of symbiont-derived secondary metabolites commonly referred to as "natural products", and highlights that symbiotic microbes represent an underexplored reservoir of natural products with unique scaffolds and promising significance in managing human healthcare and agricultural production.

Opinion on the recent development of environmentally friendly marine anti-fouling coating

Marine biofouling is a global problem that is detrimental to both moving ships and static underwater devices.Marine microorganisms tend to attach to any unprotected surface and grow into biofilm,which can be hardly removed even under high shear flow condition[1].With the long-term accumulation of marine organisms,ships suffer significantly from the increase on the net weight as well as the drag when cruising.Increased drag causes fuel power penalties of up to86%at cruising speed;it is notable even a very thin layer

Sulfosulfuron Persistence in Soil Under Different Cultivation Systems of Wheat(Triticum aestivum)

Many sulfonylurea herbicides have been used under a wide variety of agronomic conditions in numerous crops. An understanding of dissipation rate of herbicide is fundamental for predicting the fate of herbicide in soil. In order to study the sulfosulfuron persistence under different cultivation systems of wheat, a four replicated experiment was carried out in the Hashemabad Reaserch Center of Gorgan, Iran in 2010 in a split plot design with two factors. Cultivation system as the main factor consisted of six levels, including conservation tillage by Combinate, no-tillage by Baldan grain drill, conservation tillage by Chizelpacker, conservation tillage by Delta Model, surface tillage by heavy disk, and conventional tillage by moldboard plow and twice disk. Secondary factor included two levels of sulfosulfuron application(with and without sulfosulfuron). Soil samples were taken at 6 stages and soil microbial respiration and soil pH were measured as factors affecting sulfosulfuron persistence. Results showed the least time of sulfosulfuron persistence belonged to the cultivation system of no-tillage by Baldan grain drill with a half-life of 4.62 d. Then, conservation tillage by Combinate and conventional tillage with a half-life of 6.30 d and conservation tillage by Delta Model with a half-life of 9.90 d were ordered. The most time of sulfosulfuron persistence(11.55 d) was related to conservation tillage by Chizelpacker. Ninety percent reduction of sulfosulfuron concentration occurred 15.34, 20.92, 32.88, and 36.38 d after sulfosulfuron application, respectively, for no-tillage system, conservation tillage by Combinate and conventional tillage, conservation tillage by Delta Model and surface tillage, and conservation tillage by Chizelpacker. In all the cultivation systems, toxicity symptoms were not observed 40 d after spraying sulfosulfuron onto the tomato plants which were used as test plant. Effects of different cultivation systems on soil microbial respiration were also significant.