Physicochemical properties and biological activities of polysaccharides from the peel of Dioscorea opposita Thunb.extracted by four different methods

Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb.(DTTP).The influences of 4 extraction methods,namely hot water extraction(W),acidic extraction(HA),hot-compressed water extraction(HCW)and enzyme-assisted extraction(EAE),on the yields,physicochemical properties,hypoglycemic and antioxidant activities of polysaccharides from DTTP were studied and compared.Among these DTTP polysaccharides,DTTP-HA was outstanding in several respects.DTTP-HA was the most water soluble;it had the highest total carbohydrate content(85.08%),the highest uronic acid(13.20%)and the highest thermal stability.DTTP-HA and DTTP-W possessed a triple-helix structure.These 4 kinds of polysaccharides have the same types of monosaccharides,but in different molar percentages.Extraction method had a significant impact on the microstructures of the extracted polysaccharides.DTT-HA exhibited irregular structure with many holes.Among the 4 extracted methods,the DTTP-HA and DTTP-W initially exhibited higher hypoglycemic and antioxidant activities.The better bioactivities of DTTP-HA may be related to the above factors.The findings indicated that acid extraction is an effective method to extract polysaccharides with high biological activities from DTTP.

Preparation methods,biological activities,and potential applications of marine algae oligosaccharides:a review

Marine algae are valuable sources of health-promoting molecules that have been consumed by Asians for decades.Among aquatic flora,marine algae stand out in terms of high content of marine algae polysaccharides(MAP)such as carrageenan,alginate,fucoidan,laminaran,agarose,rhamnan,and ulvan.When hydrolyzed,MAP generate marine algae oligosaccharides(MAO),which have attracted interest in recent years due to their superior solubility compared with MAP.Besides,MAO have been demonstrated numerous biological activities including antioxidant,antidiabetic,anti-inflammatory,antimicrobial,and prebiotic activities.Thus,this review summarizes the main chemical classes of MAO,their sources,and the main processes used for their production(i.e.,physical,chemical,and biological methods),coupled with a discussion of the advantages and disadvantages of these methods.Highlights of the biological activities of MAO and their potential applications in food,nutraceutical,and pharmaceuticals would also be discussed and summarized.

Corn cob biochar increases soil culturable bacterial abundance without enhancing their capacities in utilizing carbon sources in Biolog Eco-plates

Biochar has been shown to influence soil microbial communities in terms of their abundance and diversity.However,the relationship among microbial abundance,structure and C metabolic traits is not well studied under biochar application.Here it was hypothesized that the addition of biochar with intrinsic properties（i.e.,porous structure）could affect the proliferation of culturable microbes and the genetic structure of soil bacterial communities.In the meantime,the presence of available organic carbon in biochar may influence the C utilization capacities of microbial community in Biolog Eco-plates.A pot experiment was conducted with differenct biochar application（BC）rates：control（0 t ha^-1）,BC1（20 t ha^-1）and BC2（40 t ha^-1）.Culturable microorganisms were enumerated via the plate counting method.Bacterial diversity was examined using denaturing gradient gel electrophoresis（DGGE）.Microbial capacity in using C sources was assessed using Biolog Eco-plates.The addition of biochar stimulated the growth of actinomyces and bacteria,especially the ammonifying bacteria and azotobacteria,but had no significant effect on fungi proliferation.The phylogenetic distribution of the operational taxonomic units could be divided into the following groups with the biochar addition：Firmicutes,Acidobacteria,Gemmatimonadetes,Actinobacteria,Cyanobacteria andα-,β-,γ-andδ-Proteobacteria（average similarity〉95%）.Biochar application had a higher capacity utilization for L-asparagine,Tween 80,D-mannitol,L-serine,γ-hydroxybutyric acid,N-acetyl-D-glucosamine,glycogen,itaconic acid,glycyl-L-glutamic acid,α-ketobutyricacid and putrescine,whereas it had received decreased capacities in using the other 20 carbon sources in Biolog Eco-plates.Redundancy analysis（RDA）revealed that the physico-chemical properties,indices of bacterial diversity,and C metabolic traits were positively correlated with the appearance of novel sequences under BC2 treatment.Our study indicates that the addition of biochar can increase culturable microbial abundance and shift bacterial genetic structure without enhancing their capacities in utilizing C sources in Biolog Eco-plates,which could be associated with the porous structure and nutrients from biochar.

Establishment of Molecular Biological Method for Identification of Bacteria by 16S rDNA and gyrB Gene

[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA was extracted for amplification of 16S rDNA and gyrB gene.The 16S rDNA and gyrB gene sequences were obtained after sequencing.Sequences were aligned and analyzed via EzBioCloud and NCBI database,and phylogenetic trees were constructed to determine the species relationship of strains.Meantime,they were compared with known strains.[Results]This method could identify 5 standard strains accurately to the species level.The 16S rDNA and gyrB gene sequences were aligned and analyzed in EzBioCloud database and NCBI database.The strain with the max score was consistent with the known strain.And the query cover and ident were both above 99%.[Conclusions]The established molecular biological method for identification of bacterial strains by 16S rDNA and gyrB gene has good accuracy,which effectively solves the problem that the laboratory identification of bacteria relies on traditional methods and the accuracy can not be guaranteed,and further improves the identification ability of laboratory bacterial strains.

Screening of Preprocessing Method of Biolog for Soil Microbial Community Functional Diversity

As one of the main methods of microbial community functional diversity measurement, biolog method was favored by many researchers for its simple oper- ation, high sensitivity, strong resolution and rich data. But the preprocessing meth- ods reported in the literatures were not the same. In order to screen the best pre- processing method, this paper took three typical treatments to explore the effect of different preprocessing methods on soil microbial community functional diversity. The results showed that, method B＇s overall trend of AWCD values was better than A and C＇s. Method B＇s microbial utilization of six carbon sources was higher, and the result was relatively stable. The Simpson index, Shannon richness index and Car- bon source utilization richness index of the two treatments were B〉C〉A, while the Mclntosh index and Shannon evenness were not very stable, but the difference of variance analysis was not significant, and the method B was always with a smallest variance. Method B＇s principal component analysis was better than A and C＇s. In a word, the method using 250 r/min shaking for 30 minutes and cultivating at 28 ℃ was the best one, because it was simple, convenient, and with good repeatability.

Analytical methods for determination of terbinafine hydrochloride in pharmaceuticals and biological materials

Terbinafine is a new powerful antifungal agent indicated for both oral and topical treatment of myco- sessince. It is highly effective in the treatment of determatomycoses. The chemical and pharmaceutical analysis of the drug requires effective analytical methods for quality control and pharmacodynamic and pharmacokinetic studies. Ever since it was introduced as an effective antifungal agent, many methods have been developed and validated for its assay in pharmaceuticals and biological materials. This article reviews the various methods reported during the last 25 years.

Effects of Different Application Methods and Application Rates of Biological Nano-Selenium on the Quality of Passion Fruit

[Objectives]To study the effects of different application methods and application rates of biological nano-selenium on the quality of passion fruit.[Methods]In this experiment,passion fruit Tainong 1 was sprayed with biological nano-selenium.The concentration of spraying refers to the recommended application rate of biological nano-selenium manufacturers.Three treatments with different concentrations were carried out:3,4.5 and 6 L/ha biological nano-selenium was sprayed on 100%root,(50%root+50%leaf surface)and 100%leaf surface of passion fruit,respectively.[Results]From the aspects of economic cost and rational utilization of resources,spraying 3 L/ha selenium fertilizer on the leaves of passion fruit played the best role in improving the quality of passion fruit.[Conclusions]To study the selenium-rich production technology of agricultural products and improve the quality of agricultural products is of great significance for improving human health and producing high-quality agricultural products.

Homotopy Analysis Method for Solving Biological Population Model

In this paper,the homotopy analysis method (HAM) is applied to solve generalized biological populationmodels.The fractional derivatives are described by Caputo's sense.The method introduces a significant improvementin this field over existing techniques.Results obtained using the scheme presented here agree well with the analyticalsolutions and the numerical results presented in Ref.[6].However,the fundamental solutions of these equations stillexhibit useful scaling properties that make them attractive for applications.

Estimation of the Biological Methods of Assessing Soil N-Supplying Capacity in Calcareous Soil

Although many biological methods are used to determine soil nitrogen supplying capacity, there are certain differences in the results for different types of soils and various ways of measurement due to the complexity of soil N conformation, the high variance of soil and microorganism, and the difference of environment. Therefore, it is not clear about which biologic incubation method is better for calcareous soil. In this study, pot experiments were performed by using 25 different calcareous surface soil samples on the Loess Plateau and taking the N uptake of wheat and corn with leaching soil initial nitrate and without leaching in pot experiments as the control to investigate the difference of eight biological incubation methods for reflecting soil nitrogen supply capacity. The eight biological methods are waterlogged incubation, aerobic incubation for 2 weeks and for 4 weeks, dry-wet alternation aerobic incubation for 2 weeks, long-term alternate leaching aerobic incubation （and N mineralization potential, No）, short-term leaching aerobic incubation, microbial biomass carbon （Bc）, and microbial biomass nitrogen （BN） method, respectively. Among these methods, the dry-wet alternation aerobic incubation and aerobic incubation for 4 weeks were the modification of the method of aerobic incubation for 2 weeks according to the actual farmland moisture. The results showed that the correlation coefficients between these methods and crop uptake N with leaching soil initial nitrate were 0.530, 0.700, 0.777, 0.768, 0.764 （and 0.790, No）, 0.650, 0.555, and 0.465, respectively （r0.05 = 0.369, r0.0l = 0.505）. While without leaching soil initial nitrate, their coefficients were 0.351, 0.963, 0.962, 0.959, 0.825 （and0.812, No）, 0.963, 0.289, and 0.095, respectively （r0.05 = 0.369, r0.01 = 0.505）. In conclusion, excluding the soil initial nitrate, the correlation coefficients between the eight methods and crop uptake N were, from high to low, N0, aerobic incubation for 4 weeks, dry-wet alternation aerobic incubation for 2 weeks, and long-term alternate leaching aerobic incubation, while including the soil initial nitrate the correlation coefficients between them increased significantly and the values were all beyond 0.950 for these four methods, including aerobic incubation for 2 weeks and for 4 weeks, dry-wet alternation aerobic incubation for 2 weeks and short-term leaching aerobic incubation. The waterlogged incubation method, Bc and BN in the calcareous soil, had lower correlation coefficient with crop uptake nitrogen compared with other methods. Thus, dry-wet alternation aerobic incubation for 2 weeks was a better index for evaluating calcareous soil N supply capacity due to some other methods having disadvantages and not suitable for the actual farmland characteristics.

Analysis method and algorithm design of biological sequence problem based on generalized k-mer vector

K-mer can be used for the description of biological sequences and k-mer distribution is a tool for solving sequences analysis problems in bioinformatics.We can use k-mer vector as a representation method of the k-mer distribution of the biological sequence.Problems,such as similarity calculations or sequence assembly,can be described in the k-mer vector space.It helps us to identify new features of an old sequence-based problem in bioinformatics and develop new algorithms using the concepts and methods from linear space theory.In this study,we defined the k-mer vector space for the generalized biological sequences.The meaning of corresponding vector operations is explained in the biological context.We presented the vector/matrix form of several widely seen sequence-based problems,including read quantification,sequence assembly,and pattern detection problem.Its advantages and disadvantages are discussed.Also,we implement a tool for the sequence assembly problem based on the concepts of k-mer vector methods.It shows the practicability and convenience of this algorithm design strategy.

Assessment of Domestic Water Sources Safety: Application of the Micro Biological Survey Method and Microbiological Profile of the Contaminating Bacteria

Water is essential for human life and it’s expected to be clean and safe. In Cameroon, government efforts to improve access to drinking water are mitigated. Many households are suffering from chronic water shortages leading to the majority of people using doubtful water sources. This study was carried out in accordance with guidelines produced by the STARBIOS2-EU funded project on Responsible Research and Innovation and aimed to assess the microbiological quality of water samples collected from domestic water sources in 3 divisions of the West region of Cameroon. 22 water samples from well water, stream, water pump and river were aseptically collected. At each sampling point, 50 mL of sample was taken aseptically and immediately transported to the laboratory for analysis. The detection of Coliforms bacteria was done using Micro Biological Survey (MBS) method. 1 mL of each sample was inoculated in the Coliforms MBS (Coli MBS) vial initially rehydrated with 10 mL of sterile distilled water. The Coli MBS vials were closed, shaken for homogenization, and then incubated at 37°C. From the initial red color of the Coli MBS vials, changes in color to yellow of the reaction vials were monitored at three different time intervals (12 h, 19 h and 24 h), corresponding to three levels of bacterial concentration. All positives samples on MBS method were selected to determine the presence of E. coli Loop full broths of Coli MBS vials were taken;streaked into the eosin methylene blue (EMB) agar plate and incubated at 37°C for 24 hours. E. coli was confirmed by observing green metallic sheen on EMB agar plate. The biochemical indole, methyl red, Voges-Proskauer and citrate (IMViC) test was performed to determine the complete microbiological profile of the water samples. Almost all the water samples were contaminated with Total Coliforms (TC). A high concentration of TC (>103 CFU/mL) was found in 8 samples (36.4%), a medium concentration (10 < x < 103 CFU/mL) was observed in 10 samples (45.5%) and 2 samples (9.1%) were low concentrated (1 < x < 10 CFU/mL). 8 samples were positive for the presence of E. coli by observing the green metallic sheen on EMB agar plates. The IMViC test confirmed the presences of 5 bacteria species: Enterobacter spp., Klebsiella spp., E. coli spp., Salmonella spp. and Shigella spp. We recommend integrating sanitary assessment in the design and implementation of water supply projects. Regular water purification using proper methods and maintenances of the water point. Regular microbiological quality assessment of water intended for human consumption should be planned and carried out.

Prevention and Control Effects of New Biological Formulations Sprayed by Different Methods on Proceras venosatus (Walker) and Tryporyza intacta Snellen in Middle and Late Stages

To screen new biological formulations, accurate and efficient application technology, field test was conducted with 72% Bacillus thuringiensis(Bt)·monosultap WP, 8% lambda-cyhalothrin·emamectin benzoate SA and 3.6% lambda-cyhalothrin·Bt SA through manual spraying and unmanned aerial vehicle spraying. Test results and comprehensive evaluation analysis demonstrated that 72% Bt·monosultap WP and 8%lambda-cyhalothrin·emamectin benzoate SA by manual spraying and unmanned aerial vehicle spraying had good prevention and control effect on strains and internodes damaged by Tryporyza intacta Snellen in middle and late stage, which were ideal new biological formulations with high effi-ciency and low risk for prevention and control of T. intacta in middle and late stage, and could be popularized in sugarcane area. 72% Bt·monosultap WP at the dose of 3 000 g/hectare and 8% lambda-cyhalothrin·emamectin benzoate SA at the dose of 750 mL/hectare could be sprayed in mid September at the peak occurrence period of the forth and fifth generations of T. intacta and Proceras venosatus. Agents were diluted with 900 kg water per hectare, and manually sprayed with electric knapsack sprayer; or agents were diluted with 15 kg of Haoyang aerial control special addi-tives and water per hectare, and sprayed with unmanned aerial vehicle. The control effect against borer-damaged strain rate was above 81.3% and that against borer-damaged internode rate was above 88.6%.

Clinical Value of Molecular Biological Methods in Respiratory Tuberculosis in Children

The pattern of clinical forms of respiratory tuberculosis in children shows a preponderance of intrathoracic lymph node tuberculosis （89.4%） that is characterized by a complicated process in every third child under present-day conditions. Positive result of PCR closely correlates with the severity and extent of the specific process in children. Real-time PCR （RT-PCR） was ascertain to exhibit the highest sensitivity in detecting Mycobacterium tuberculosis DNA in children with primary generalized tuberculosis （62.5%） and in those with a disseminated specific process （55.6%）, which was much higher than conventional bacteriological study of diagnostic materials. By taking into account the findings, the RT-PCR detection of M. tuberculosis was considered as a substantial criterion for evaluating the magnitude of specific changes and the degree of tuberculosis infection activity in children.

Biological activities of gastropods secretions:snail and slug slime

Gastropods,a mollusk class including slugs and snails,represent an extraordinarily diverse and ecologically significant group of organisms featuring the largest class of invertebrates.They can be classified as aquatic and terrestrial animals having coiled shells,although some species have reduced or absent shells.Their unique body structure includes a muscular foot for locomotion,a visceral mass containing essential organs,and a distinct head region with sensory organs such as tentacles and eyes.They are used to secrete a complex mixture of glycoproteins,enzymes,peptides,mucus and other bioactive compounds,namely slime,which represents a tool to allow locomotion,protection,and interaction within different habitats.The biological activities of the slime have attracted considerable interest due to their diverse and potentially valuable properties ranging from defense mechanisms to potential therapeutic applications in wound healing,antimicrobial therapy,management of inflammation,and neurological disorders.This review aims at exploring the beneficial effects of snail and slug slime focusing,in particular,on the improvement of the biological processes underlying them.Continued exploration of the intricate components of these slimy secretions promises to discover new bioactive molecules with diverse applications in various scientific and industrial fields.

鳄梨油的提取、营养组成及生物学功能研究进展

鳄梨油富含单不饱和脂肪酸(尤其是油酸)、生育酚和植物甾醇等营养成分,具有抗氧化、改善心血管健康、预防糖尿病、抗癌和降血压等生物学功能。随着研究的不断深入,鳄梨油越来越受到食品及生物医药领域的青睐,其市场规模也在逐年扩大。通过梳理近年来国内外报道的有关鳄梨油的研究成果,该文从鳄梨油的提取工艺、营养组成和生物学功能等方面展开综述,为鳄梨油提取工艺的创新、营养功效及其潜在机制的深入研究提供理论参考。

落叶型棉花黄萎病的生物学特征及药剂防治分析

【目的】比较研究新疆昌吉市和沙湾市落叶型棉花黄萎病病原菌的生物学特性,分析的多菌灵、乙蒜素、唑酮乙蒜素、枯草芽孢杆菌和哈茨木霉菌5种农药对棉花黄萎病的防治效果,筛选出高效的药剂用于指导棉花病害防治。【方法】采用菌丝生长速率法,通过不同离子、pH值、碳源及温度生长的适应,分析各病原菌的主要生物学特性,并对5种农药进行室内毒力测定。【结果】昌吉市和沙湾市各病原菌生长最适温度为20~25℃,最适离子培养基为Ca^(2+),最适pH值5~7,最适碳源是蔗糖。5种供试药剂均对各病原菌具有明显的抑制效果。多菌灵、枯草芽孢杆菌、哈茨木霉菌对病原菌的抑制作用极强,昌吉市多菌灵、枯草芽孢杆菌、哈茨木霉菌其抑制中浓度EC_(50)值仅分别为0.2923~0.8193μg/mL、0.01661~0.02695μg/mL和0.1015~0.8846μg/mL,沙湾市EC_(50)值分别为0.3588~5.694μg/mL、1.813×10^(-2)~2.727×10^(-2)μg/mL和0.1810~0.6088μg/mL;而乙蒜素、唑酮乙蒜素对病原菌的防效最差,其EC_(50)在昌吉市分别高达71.04、111.6μg/mL,沙湾市分别为79.22、171.7μg/mL。【结论】昌吉市、沙湾市的各病原菌最适生长的温度为25℃,含Ca^(2+)培养基为最适离子培养基。各病原菌在pH值5~7时生长速率最快,最适生长环境为酸性环境,对偏碱性环境也有较好的耐受性。微菌核在偏碱性的环境下更易形成,在以蔗糖为碳源的培养基上的生长速率最快。多菌灵、枯草芽孢杆菌、哈茨木霉菌对棉花黄萎病菌有强抑菌作用,可在昌吉市和沙湾市用于防治棉花黄萎病。

食用菌多糖功能活性的研究进展

食用菌多糖是一种大分子碳水化合物。几十年来,研究人员对食用菌多糖的提取、分离纯化、功能性作用等进行了相关研究。文章综述了热水浸提法、酸碱提取法、酶提取法、超声波提取法、闪式提取法、亚临界水提取法、超临界流体萃取法等不同食用菌多糖的提取方法,并简述了其优缺点;阐述了食用菌多糖的组成结构和食用菌多糖在抗氧化、抗肿瘤、免疫调节、降血糖、降血脂、调节肠道菌群等方面的功能,并展望了其未来的研究方向。

蝴蝶兰种质资源生物学性状综合评价

以收集的57份蝴蝶兰种质资源为研究对象,对其23个生物学性状进行调查并分析,明确影响蝴蝶兰种质资源生物学性状综合评价的主要因子,采用层次分析法与K-Means聚类分析方法相结合,建立蝴蝶兰种质资源生物学性状综合评价体系,以期能够较为全面的评价现有种质,对现有种质资源进行分级,为蝴蝶兰种质资源的利用、新品种选育及栽培推广提供参考依据。结果表明:花部形态(C1)是蝴蝶兰综合性状评价的主要因子,花色所占比重最大,花梗形态(C2)次之,植株形态(C3)权重最低;综合评价得分最高的是‘光芒四射’(得分4.2706);花部形态评价得分最高的是‘招财猫’和‘光芒四射’(得分2.5010),植株形态得分最高的是‘龙树枫叶’(得分0.7472),花梗形态得分最高的是‘1713’(得分1.1554);根据评价得分将57份种质分为4个等级,其中优秀等级9个,占比15.79%;良好18个,占比31.58%;中等20个,占比35.09%;及格10个,占比17.54%。

耕作方式和药剂处理对小麦产量和赤霉病发生的影响

研究旨在明确不同耕作措施和药剂处理对小麦产量以及赤霉病防控效果的影响。2019-2022年,设置2种耕作方式(深旋+秸秆旋埋和免耕+秸秆覆盖)、3种药剂(对照、化学药剂和生防制剂)以及5个小麦品种,研究不同耕作和秸秆利用方式下,小麦赤霉病发生情况、药剂防治效果以及基因型差异。结果表明,2022年赤霉病发生较2020年重,主要与花后的降雨量有关;免耕+秸秆覆盖处理的产量较深旋+秸秆旋埋处理高11.76%~58.82%,主因是穗数较高,免耕+秸秆覆盖的土壤禾谷镰刀菌含量和病籽率明显低于旋耕处理,但病穗率和子囊壳数量显著高于深旋+秸秆旋埋处理;在赤霉病发生较轻年份,生防制剂防控效果最佳,其次是化学药剂处理,但在赤霉病发生偏重年份,化学药剂的防治效果略优于生防制剂;‘绵麦902’产量高但易感染赤霉病,‘川麦618’产量较高且赤霉病抗性好。总体来看,免耕秸秆覆盖产量高,选用抗性品种和合理运用药剂能够有效抑制小麦赤霉病的发生。

一株云南木霉菌培养条件的优化及其对茶炭疽病的防控研究

为优化对茶炭疽病菌Colletotrichum camelliae有拮抗作用的云南木霉菌Trichodema yunnanense的发酵培养条件,并明确发酵液对茶炭疽病的防控效果,以对C.camelliae的抑菌率为评价指标,通过单因素和响应面试验,优化云南木霉菌的发酵条件并获得发酵液,比较其对茶炭疽病的抑菌活性、离体叶片和盆栽茶树叶片防效及茶树生长的影响。结果显示,T.yunnanense的最佳发酵条件为马铃薯200 g·L^(-1)、甘露醇18.85 g·L^(-1)、酵母浸膏4.73 g·L^(-1)、装液量372.60 mL·L^(-1)、培养温度25℃、pH 6.6、12L∶12D。10%的发酵液对C.camelliae的抑菌率达92.61%,对感染茶炭疽病的离体茶树叶片与盆栽茶树叶片的防效分别为63.71%与68.95%,均显著高于哈茨木霉菌(T.harzianum)可湿性粉剂与多菌灵的防效。同时,10%发酵液处理后的茶树幼苗根长提升69.16%,根鲜重提升215.70%,株高增加42.13%,地上部鲜重增加212.11%。表明T.yunnanense发酵液兼具抗菌和促生作用。研究结果为T.yunnanense在茶炭疽病生物防治中的应用奠定了一定的理论基础。