Biological Characteristics of Trehalose and Its Protective Effect on Food Fermentation Starters during Lyophilization

This paper reviewed the unique biological function of trehalose and its mechanism of stabilizing biological macromolecules and the research progress in the protective effect of trehalose on lactic acid bacteria fermentation starters during lyophilization in food production.The application of trehalose in food industry was prospected.

In vitro growth, differentiation and biological characteristics of neural stem cells

OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was undertaken to identify English articles about the growth of neural stem cells in vitro published from January 2000 to October 2006 by using the keywords of ＂neural stem cells, bone marrow mesenchymal stem cells （BMSCs）, umbilical cord blood stem cells, embryonic stem cells （ESC）, separation methods, neural growth factor＂. And relevant articles published in IEEE/IEE Electronic Library （IEL） database, Springer Link database and Kluwer Online Journals were also searched, Chinese relevant articles published between January 2000 to October 2006 were searched with the same keywords in Chinese in Chinese journal full-text database. STUDY SELECTION ： The articles were primarily screened, and then the full-texts were searched. Inclusive criteria： （1） Articles relevant to the biological characteristics and classification of neural stem cells; （2） Articles about the source, separation and differentiation of the ESCs, BMSCs and umbilical cord blood stem cells. The repetitive studies and reviews were excluded. DATA EXTRACTION ： Thirty articles were selected from 203 relevant articles according to the inclusive criteria Articles were excluded because of repetition and reviews. DATA SYNTHESES ： Neural stem cells have the ability of self-renewing and high differentiation, and they are obtained from ESCs, nerve tissue, nerve system, BMSCs and umbilical cord blood stem cells. ESCs can be separated by means of mechanical dissociation is better than that of the trypsin digestion, BMSCs by density gradient centrifuge separation, hemolysis, whole-blood culture, etc., and umbilical cord blood stem ceils by Ficoil density gradient centrifugation, hydroxyethyl starch （HES） centrifugation sedimentation, etc. Neural growth factor （NGF） and other factors play an important role in the growth of NSCs, such as transforming growth factor （TGF） is an important player in repairing organs, NGF accelerates the process of growth, insulin-like growth factor serves importantly in the differentiation of stem cells into neuron-like cells. CONCLUSION ： As unipotent stem cells, NSCs have the abilities of self-renewal and potential of high differentiation. The method of mechanical dissociation is better than trypsin digestion in e separating ESCs. However, density gradient centrifuge separation is better than other methods in the separation of the BMSCs. NGF and other factors play an important role in the growth of NSCs.

Biological Characteristics of Fusarium oxysporum f. sp.niveum Isolated from Watermelon Cultivated in Plastic Greenhouse and Indoor Toxicity Determination of Different Fungicides in Hainan Province of China

[ Objective] The paper was to study biological characteristics of Fusarium oxysporum f. sp. niveum in watermelon cultivated in plastic greenhouse in Hainan Province of China and to determine indoor toxicity of fungicides. [ Method] Effects of various factors on mycelial growth and spore germination were stud- ied, and the lethal temperature of spores and indoor toxicity of fungicides were also determined. [Result] The fungal mycelium had a better growth rate on water- melon juice medium than the others. The optimum temperature for mycelial growth and spore germination were 28 ℃ and 30 ℃, and the optimum pH values were 7 - 8 and 7 - 9, respectively. Light-dark alternation was conducive for mycelial growth. The lethal temperature of spore was 60 ℃ for 5 min. The fungal mycelium grew better while taking fructose and glucose as carbon sources and yeast extract and peptone as nitrogen sources. Toxicity determination showed that 50% pro- chloraz-manganese chloride complex WP had the greatest inhibition effect on mycelial growth, with the ECso value of 0.730 9 μg/mL; followed by 32.5% benzoic azoxystrobin SC, 30% benzoylate· propieanazol EC, 10% difenoconazole WG, 25% bromothalonil · carbendazim WP and 25% bromothalonil WP, with the ECso values from 1.884 7μg/mL to 8. 161 0μg/mL. [Conclusion] The study provided basic data for field control against F. oxysporum f. sp. niveum on watermelon cultivated in plastic greenhouse in Hainan Province.

Biological characteristics of marine bacterium S-9801 strain and its culture conditions of pigment production

Strain of Flavobacterium sp.(S-9801),was screened from 207 strains of marine bacteria isolated from the Bohai Sea continental shelf and the Zhujiang Estuary,for its red pigment production.The biological characteristics of strain S-9801 and culture conditions of pigment production have been checked out in this study. The color of the bacterial colony on 2216E medium was from coccineus to rose bengal. Optimum culture conditions were sodium chloride concentration(g/dm3),10～30;pH,3～8;temperature,25～28℃;tryptone and yeast extract as nitrogen sources and glucose as carbon source. Under optimum conditions,pigment accumulation started after 12 h,reaching a maximum rate of synthesis at 36 h.

Study on Biological Characteristics and Toxicity Determination of Colletotrichum orbiculare Causing Anthracnose of Watermelon in Hainan Province

[Objective] This paper was aimed to study the biological characteristics of Colletotrichum orbiculare（Berk.et Mont.） Arx, and accomplish the preliminary screening the test of fungicides. [Method]The pathogen was isolated from the infected leaves of watermelon collected from greenhouse in Hainan Province. The biological characteristics of C. orbiculare and indoor toxicity of fungicides were studied. [Results] The mycelium grew fastest on the medium with leaf extract of watermelon. The optimum temperature for mycelial growth and spore germination was 28 and 30 ℃, and the optimum pH was 7-9 and 6-8, respectively. The continuous darkness condition was most suitable for mycelial growth. The lethal temperature of spore was 55 ℃ water bath for 10 min in water bath. The suitable carbon sources were maltose, L-arabinose and glucose, and the suitable nitrogen sources were yeast extract, beef extract and peptone. In the indoor toxicity determination, 32.5% Benzoic azoxystrobin SC, 50% Dichlorotetrakis WP and 10% Difenoconazole WG showed better inhibition effects against the mycelial growth of C. orbiculare, with the EC50 values of 0.018 0, 0.060 2 and 0.471 5 μg/ml, respectively. [Conclusion]The research provided theoretical basis for the control of watermelon anthracnose in watermelon fields.

ESTABLISHMENT OF A MAMMARY CANCER CELL LINE Ca 761-86 AND ITS BIOLOGICAL CHARACTERISTICS IN INBRED 615 MICE

A cell line designated as Ca 761-86 has been established from the solid mouse mammary cancer (Ca 761) by suspension culture. It has been passaged for more than 212 generations. Moderate round cells were predominant and most of them were mononuclear. Some characteristics of malignant cells and A-type viral-like particles were observed by electron microscopy. The results of cytochemical studies (DNA, RNA, SDH, 5' AMPase, ACP etc.) were comparable to the ultramicroscopic results. It multiplied approximately 27.4 fold on day 5 with mitotic index reaching 1.8% on day 3. This cell line was a hyperdiploid with karyotype of 45 or 45, -2X, tril2, tri17, +M1-5. Cell agglutination was observed when treated with ConA (≥7 fig, ml). Spontaneous agglutination might also take place without adding any ConA. After 5×106 cells of Ca 761-86 suspension were transplanted into the normal inbred 615 mice by different ways (subcutan eous, intrafoot-pad or intraperitoneal), the transplan lability rate reached 100%. Spontaneous remission was never observed and its metastatic ability reserved. PPLO were not detected. Ca 761-86 may be of value for practical purposes.

ESTABLISHMENT OF A CELL LINE INFECTED WITH SRS MOUSE LEUKEMIA VIRUS AND ITS BIOLOGICAL CHARACTERISTICS

NIH/3T3 cells were infected with a cell-free extract from the mouse SRS ascltic tumor and propagated at vitro. Experimental results showed that type A and type C virus particles were observed in the cytoplasm of infected NIH/ 3T3 cells by electron-microscopy, X-C assay and reverse transcriptase were both positive. Free proviral-DN A of the leukemia vims was found in the infected NIH/3T3 cell by Southern blot hybridization.Morphologically, the NIH/3T3 cells infected in vitro appeared spherical and formed monolayer cell colonies of various sizes after 24 - 48 hours. When the cultured cells were Inoculated into nude mice (BALB/ c, nu nu ) subcutaneously, flbrosarcoma was Induced, 100%. Inoculation of the cell-free extract of the same cultured cells into Inbred SW-1 newborn mice, resulted in the production of lymphocytic leukemia and lymphoma in 52. 3% within 191 days.

Study on Biological Characteristics of Livestock Eperythrozoon

Based on the study of infection and morphological characteristics of 12 kinds of livestock Eperythrozoon,disinfection test by drugs in vitro,disinfection test by ultraviolet light,Eperythrozoon survival test at different times and temperatures,drug sensitivity test and clinical treatment of infected swines were carried out on Eperythrozoon suis and Eperythrozoon wenyonii to further study the biological characteristics. Test results showed that infection level of livestock Eperythrozoon was high,while morbidity was low. Eperythrozoon suis and Eperythrozoon wenyonii could survive for 1 year at 3- 5 ℃,180 d at 16- 26 ℃ and 30 min at- 20 ℃,while which died instantly at 65 ℃. Eperythrozoon was sensitive to general chemical disinfection drugs,while not sensitive to ultraviolet light disinfection. Transmission of Eperythrozoon mainly included contagious transmission and vertical transmission. Results of drug sensitivity test showed that Eperythrozoon was sensitive to Tetracycline and antigen insect drugs. Sizes and shapes of different livestock Eperythrozoon were different. The study provided a scientific basis for the effective prevention and treatment of livestock Eperythrozoonosis.

Biological Characteristics and Culture Conditions of Hericium coralloides(Scop.)Pers.

[Objectives]To study the biological characteristics and culture conditions of Hericium coralloides(Scop.)Pers.[Methods]The wild H.coralloides strain of Changbai Mountain was used as the experimental material to conduct a single factor test on its biological characteristics.[Results]The ideal available carbon source and nitrogen source are glucose and ammonium sulfate,respectively,the pH is 3.5-4.0,and the temperature is 20-22℃.Through the orthogonal experiment of 4 factors and 4 levels,it is found that the degree of influence of the 4 factors on H.coralloides is temperature>pH>nitrogen source>carbon source.[Conclusions]The optimum conditions for the mycelium culture of H.coralloides:the carbon source is glucose,and the nitrogen source is yeast extract or peptone,and pH is 3.5-4.0,and temperature is 20-22℃.

Biological Characteristics of Marssonina coronaria and Its Pesticide Screening in Laboratory

Chaenomeles sinensis spot leaf cast is one of the most serious diseases in production. The biological characteristics of Marssonina coronaria were studied and the suitable pesticides against the pathogen were screened in the paper, to provide a scientific basis for studies on epidemic regularity and control of the disease. The effects of different nutrition and environmental conditions as well as nine pesticides on the mycelial growth of M. coronaria were investigated in this paper. The results indicated that the mycelium grew well on the PDA medium with pH of 7.0, and soluble starch and urea were suitable carbon and nitrogen sources, respec- tively. The lethal temperature was 45 ~C, and the light-dark alternation （12/12h） was benefit for mycelial growth. Among the nine tested pesticides, carbendazim was the most effective agent, with ECs0 of 8.78 mg/L, and its relative inhibition rate was 85 % under the recommended concentration of 1.0 mg/L. Mancozeb was the least effective agent, and its relative inhibition rate was only 40.8% under the recommended concentration of 1.67 mg/L.

Study on Biological Characteristics of Caged Tetrao parvirostris

The characteristics of digestive system,breeding habits,feather growth and molting of Tetrao parvirostris were studied,in order to provide the scientific basis for artificial breeding of T.parvirostris.

Biological Characteristics of Alternaria tenuissima on Dendrobium sandidium Wall.et Lindl.

Biological characteristics of Alternaria tenuissima on Dendrobium sandidium Wall. et Lindl. were studied. The result showed that A. tenuissima on D. sandidium Wall. et Lindl. could grow at temperature 5 -35 ℃and pH value of 2 - 10, the optimal temperature and pH value were 25℃ and 7 for its growth and sporulation, respectively. Starch was the optimal carbon sources and peptone was the optimal nitrogen source for the growth and sporulation of bacterial colony, re- spectively; PSA and PCA were the optimal media for its growth and sporalation, respectively.

ESTABLISHMENT OF A MURINE ASCITES HEPATOMA CELL LINE H_(22)-F_(25)/L AND ITS BIOLOGICAL CHARACTERISTICS

Having been passed for 160 generations, a cell linedesignated as H22-F25/L was established from a murine tumorlymphatic metastatlc model H22-F25 which had been set up in our college. The cell line was in suspension culture with a rapid proliferation and stable growth. The peak tune of cell division and proliferation was 48 and 96 hours after culture. In a week, the cell number was Increased by 25 tunes. H22-F25/L still keeps the features of a poorly differentiated cancer. Its tumor inducing rate (in vivo)was 100% in 615 mice. Lymph node metastasis rate was 50% and pulmonary metastasis rate 10%. H22- F25/ L Is a population of heterogenetlc tumor cells Including 2 stem cell lines (the model number of chromosomes being 43 in 40% tumor cells and 86 in 32%) and some side lines. The common marker chromosomes M1, M2, M3 and M4 were present in all stem and side lines.

A STUDY OF THE BIOLOGICAL CHARACTERISTICS OF HUMAN HEPATOMA XENOGRAFTS IN NUDE MICE AFTER IRRADIATION

Cell growth kinetics and changes in AFP in nude mice with human hepatoma xenografts were evaluated using the flow cytometry method. After receiving 10 Gy of radiation, the mice showed a marked delay in tumor growth; approximately 1 Gy of radiation caused a tumor growth delay of one day. Irradiation altered various phases of the cell cycle. An acute and temporary block of G2 cells was characteristic; FCM measurements demonstrated that about 58% of cells were blocked in the G2 phase and this blocking effect lasted 90 hours after an irradiation of 10 Gy. This indicated that human hepatoma xenografts in nude mice were quite sensitive to irradiation. It was also noted that the AFP decreased for 96 hours after irradiation. Changes in G2 cells after irradiation may be closely related to changes in AFP.

Morphological and Biological Characteristics of Rhynchaenus empopulifolis in Tai’an,China

Rhynchaenus empopulifolis is a defoliator harming poplar,and its occurrence is reported in Tai’an area for the first time.Through indoor rearing and forest investigation,the morphological,biological and damage characteristics of R.empopulifolis in Tai’an were observed,and color pictures of each instar and local characteristics of adult as well as damage symptoms were provided,in order to lay a theoretical basis for rapid identification and precise control of R.empopulifolis.

Biological Characteristics and Research Status of Acetic Acid Bacteria for Fruit Vinegar Brewing

Fruit vinegar is a new beverage emerging in recent years because of its rich nutrition. At present, acetic acid bacteria are main strains used in the fruit vinegar production. Acetic acid bacteria are a general term for a class of bacteria that can oxidize ethanol to acetic acid. This paper mainly summarized the biological characteristics and research status of acetic acid bacteria for fruit vinegar brewing, in order to provide a theoretical basis for the selection of high-quality acetic acid bacteria for fruit vinegar brewing.

Biological characteristics of Acanthocinus carinulatus, a new record insect pest in Aershan, Inner Mongolia

Biological characteristics of a new record pest insect Acanthocinus carinulatus Gebler has been reported in China. During the last few years, outbreaks of this insect in larch （Larix gmelinii Rupr.） plantations of Aershan, Inner Mongolia have occurred. Each year one generation is born. The insects only damage the phloem in L. gmelinii, overwinter in galleries as larvae and pupate in May of the following year. The pupation culminates in late May. The pupal phase lasts about 45 d. Adults emerge in early June and require nutrition after emergence. Mating and oviposition occur from late June to early August and the adult males and females and may copulate many times in their lifetime. The female adults lay eggs in bark crevices. Oviposition sites with one egg occupy 70.5% of all sites, sites with three eggs occupy 6.8% and 22.7% of all crevices are without eggs. Eggs stay in this stage for a period of 7 to 11 d. Larvae hatch in early July and hibernate in early September. The rate of successful hatching is only 37.8%.

Biological Characteristics of Root Rot Pathogen on Sambucus chinensis

Effects of different media,pH values,temperatures,carbon and nitrogen sources on mycelial growth and sporulation of root rot pathogen on Sambucus chinensis was determined in the paper.The results showed that root rot pathogen on S.chinensis was identified as Fusariumsp.The mycelial growth and sporulation of Fusariumsp.in PSA medium was the best;the optimal temperature for mycelial growth and sporulation was from 25℃ to 30℃ and the optimal temperature was 28℃;the suitable pH values for mycelial growth and sporulation was from 5 to 7,and the optimum pH value was 6;the absence or presence of carbon sources had significant effect on growth of Fusariumsp.;sucrose was the best carbon source utilized in mycelial growth,while lactose was the worst; KNO3 was the best nitrogen source utilized in mycelial growth,while（NH4） 2 SO4 was the worst one.

Biological characteristics and conservation genetics of the narrowly distributed rare plant Cinnamomum chago(Lauraceae)

Cinnamomum chago(family Lauraceae) is an essential source of timber and oil.This plant is narrowly distributed in the western part of the Yunnan Province.In this study,the distribution,habitat,and biological characteristics of C.chago were examined through field investigation.The genetic diversity and the variation of the remnant populations were also studied using the inter-simple sequence repeat technique.Results showed that C.chago is mainly distributed in the upstream tributary mountains of Lancang River in Yunlong County of Yunnan Province.The species distribution exhibited a fragmented pattern with five isolated populations and high-frequency anthropogenic interference.A combination of morphological features(opposite leaves,pinnate leaf veins,absence of glandular fossa,large drupe,small punch,and pollen surface with triangular spike grain,with cushion bumps at the base) indicated that C.chago is a key phylogenetic taxon between the two sections of Asian Cinnamomum plants(Sect.Camphora(Trew) Meissn.and Sect.Cinnamomum).Analysis of the genetic diversity of C.chago indicated that it has a moderately high level of genetic diversity at the population and species levels(populations level:N_e = 1.629,H = 0.348,1= 0.504,and PPB = 83.3%;species level:N_e = 1.864,H = 0.460,1 = 0.652,and PPB = 100%).Analysis of molecular variance revealed that 17%of the genetic variation was divided between the populations,whereas 83%was observed within the populations.Based on these results,we suggest the inclusion of C.chago in the Wild Plants with Extremely Small Populations in China.Moreover,the species should be given special attention and protection.Some strategies were proposed for the conservation of the C.chago populations.