Effects of culture conditions on ligninolytic enzymes and protease production by Phanerochaete chrysosporium in air

The production of ligninolytic enzymes and protease by Phanerochaete chrysosporium was investigated under different culture conditions. Different amounts of medium were employed in free and immobilized culture, together with two kinds of medium with different C/N ratios. Little lignin peroxidase （LIP） （〈 2 U/L） was detected in free culture with nitrogen-limited medium （C/N ratio： 56/2.2, in mmol/L）, while manganese peroxidase （MnP） maximum activity was 231 and 240 U/L in 50 and 100 ml medium culture, respectively. Immobilized culture with 50 ml nitrogen-limited medium gave the highest MnP and LiP production with the maximum values of 410 and 721 U/L separately on the day 5; however, flasks containing 100 ml nitrogen-limited medium only produced less MnP with a peak value of 290 U/L. Comparatively, carbon-limited medium （C/N ratio： 28/44, in mmol/L） was adopted in culture but produced little MnP and LiE Medium type had the greatest impact on protease production. Large amount of protease was produced due to glucose limitation. Culture type and medium volume influence protease activity corporately by affecting oxygen supply. The results implied shallow immobilized culture was a possible way to gain high production of ligninolytic enzymes.

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.

CLONAL PROLIFERATION AND LONG-TERM CULTURE OF MALIGNANT LYMPHOMA CELLS UNDER SERUM-FREE CULTURE CONDITIONS

We developed a serum-free culture system that promoted the growth of B cell colonies in peripheral blood, bone marrow, lymph nodes and cerebrospinal fluid (CSF) from 7 out of 8 patients with non-Hodgkin's lymphomas of B cell type. The culture cells were pretreated with or without galactose oxi-dase (GO) prior to plating. Colony growth was best supported with BCGF. A moderate increment was observed with rIL-3, as well as rIL-1β and even to a lesser degree, by rlL-2, while B cell stimulating factor-2 (rBCSF-2) and rlL-1β did not show significant activity. rGM-CSF and rG-CSF had little effect, while rM-CSF enhanced the formation of lymphoma colonies. The cells from different patients had different requirements for Staphylococcus aureus protein A and GO pretreatment. It reflected the differences in activation and differentiation status and surface properties of lymphoma cells from different patients. The cells from CSF of one patient were successfully maintained in serum-free culture medium supplemented with 10% BCGF or 5% PHA-LCM for more than 4 months. The long-term culture cells were EBV negative, phenotypically consistent with B cells and gene rearrangements for JH, Kappa and myc. This serum-free culture system allowed extensive analysis of the growth requirements for clonogenic precursors.

Optimization of Streptomyces caelestis Culture Conditions and Preliminarily Determination of Its Antifungal Components

Streptomyces caelestis FAS is an actinomyces strain isolated with Ustilago scitaminea as an indicator. With GAUZE s medium as the basic medium, carbon source and nitrogen source in the medium and ventilation volume were optimized, and the antifungal substances produced by S. caelestis FAS were preliminarily determined through organic solvent extraction and ammonium sulfate precipitation. The results showed that the antifungal components produced by S. caelestis FAS were proteins, and the optimal culture conditions were using corn flour as carbon source and KNO 3 as nitrogen source and culturing in 250 ml triangular flask added with 70 ml of culture medium. The crude protein obtained under these culture conditions had the best antifungal effect with an inhibition zone diameter of 25 mm. This study will provide a scientific basis for further study on the antifungal mechanism and application of S. caelestis FAS.

Biological identification and determination of optimum growth conditions for four species of Navicula

Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning elec-tron microscopy （SEM） and sequence comparisons of two segments of genes （small ribosomal subunit and large subunit of Rubisco）, the species were identified asNavicula perminuta,N. pseudacceptata,N. vara, andN. rhynchocephala. Based on phylogenetic analysis and culture trials,there was a close relationship betweenN. perminutaandN. vara. Growth of these species was evaluated using measurements of optical density at 680 nm （OD680） under various environmental factors. Results showed that the optimum culture conditions were 25°C, 50-100 μmol photons m-2 s-1, pH 8.0, and salinities from 25 to 30. However, the favor-able salinity forN. perminuta was surprisingly high at 35. Nutrient requirement analysis demonstrated that growth ofNavicula depended on the availability of SiO32-. Their relative growth rates （RGR） peaked at the highest tested level （0.25 mmol/L）. The optimal concentrations of NO3-and PO43- were 3.6 mmol/L and 0.18 mmol/L, respectively. Culture of theseNavicula species for abalone or sea cucumber aquaculture should take these factors into consideration.

Priming strategies for controlling stem cell fate: Applications and challenges in dental tissue regeneration

Mesenchymal stromal cells(MSCs)have attracted intense interest in the field of dental tissue regeneration.Dental tissue is a popular source of MSCs because MSCs can be obtained with minimally invasive procedures.MSCs possess distinct inherent properties of self-renewal,immunomodulation,proangiogenic potential,and multilineage potency,as well as being readily available and easy to culture.However,major issues,including poor engraftment and low survival rates in vivo,remain to be resolved before large-scale application is feasible in clinical treatments.Thus,some recent investigations have sought ways to optimize MSC functions in vitro and in vivo.Currently,priming culture conditions,pretreatment with mechanical and physical stimuli,preconditioning with cytokines and growth factors,and genetic modification of MSCs are considered to be the main strategies;all of which could contribute to improving MSC efficacy in dental regenerative medicine.Research in this field has made tremendous progress and continues to gather interest and stimulate innovation.In this review,we summarize the priming approaches for enhancing the intrinsic biological properties of MSCs such as migration,antiapoptotic effect,proangiogenic potential,and regenerative properties.Challenges in current approaches associated with MSC modification and possible future solutions are also indicated.We aim to outline the present understanding of priming approaches to improve the therapeutic effects of MSCs on dental tissue regeneration.

Growth and decline of arboreal fungi that prey on Bursaphelenchus xylophilus and their predation rate

Pine wilt disease caused by pine wood nema-todes is a deadly disease of the genus Pinus requiring strong quarantine measures.Since its discovery,it has been widely distributed throughout the world.China is one of the coun-tries with a severe rate of infections due to its abundant pine resources.In this study,nematode-trapping fungi were collected from pine trees in Ninghai City,Zhejiang Prov-ince,which is the key area of pine wilt control in Febru-ary,May,September,October and November.The results showed that nematode-trapping fungi of pine are abundant,especially the number and species detected in each month and are quite different;species of fungi in July,Septem-ber and November were more numerous and had higher separation rates.The dominant species in November was Arthrobotrys oligospora followed by Arthrobotrys cladodes;July and September it was A.cladodes.In each part of the tree,A.cladodes was the most widely distributed with a high separation rate.Therefore,it is the dominant fungal species in the area.Arboreal Bursaphelenchus xylophilus-trapping fungi are dependent on pine wood nematodes,and none were isolated from healthy pine trees.More arboreal B.xylophilus-trapping fungi were found under the bark than in the xylem.There is a close relationship between arboreal B.xylophilus-trapping fungi and pine wood nematodes.How to make use of these resources to reduce the damage of pine wood nematode fusarium is the focus of future research.

Pathway for interferon-gamma to promote the differentiation of cholinergic neurons in rat embryonic basal forebrain/septal nuclei

BACKGROUND： The supernatant of interferon-gamma （IFNγ） co-cultured with neonatal rat cortical glia can promote the cells in embryonic basal forebrain/septal nuclei to differentiate into cholinergic neurons, but the mechanism is still unclear. OBJECTIVE： To analyze the pathways for IFNγ to promote the differentiation of primarily cultured cholinergic neurons in rat embryonic basal forebrain/septal nuclei through culture in different conditioned medium. DESIGN： A controlled experiment taking cells as the observational target. SETTINGS： Department of Biochemistry and Molecular Biology, Youjiang Medical College for Nationalities; Department of Cell Biology, Beijing University Health Science Center. MATERIALS： Sixty-four pregnant Wistar rats for 16 days （250-350 g） and 84 Wistar rats （either male or female, 5-7 g） of 0-1 day after birth were provided by the experimental animal department of Beijing University Health Science Center. Rat IFNγ were provided by Gibco Company; Glial fibrillary acidic protein by Huamei Company. METHODS： The experiments were carried out in the Department of Cell Biology, Beijing University Health Science Center and Daheng Image Company of Chinese Academy of Science from July 1995 to December 2002. ① Interventions： The nerve cells in the basal forebrain/septal nuclei of the pregnant Wistar rats for 16 days were primarily cultured, and then divided into four groups： Blank control group （not any supernatant and medium was added）; Control group （added by mixed glial cell or astrocyte conditioned medium）; IFNγ group （added by mixed glial cell or astrocyte conditioned medium＋IFNγ）. Antibody group （added by mixed glial cell or astrocyte conditioned medium＋IFNγ＋Ab-IFNγ）. Mixed glial cell or astrocyte conditioned medium was prepared using cerebral cortex of Wistar rats of 0-1 day after birth. ② Evaluation： The immunohistochemical method was used to perform the choline acetyltransferase （ChAT） staining of cholinergic neurons. The ChAT positive cells were counted. MAIN OUTCOME MEASURES： Comparison of ChAT positive cells in rat basal forebrain and septal nuclei in different conditioned medium. RESULTS： ① ChAT positive cells in mixed glial cell conditioned medium： The ChAT positive cells in the IFNγ group and antibody group were significantly more than those in the control group （P 〈 0.01）. ② ChAT positive cells in astrocyte conditioned medium： The ChAT positive cells in the IFNγ group were significantly more than those in the control group, but there was no significant difference between the antibody group and control group （P 〉 0.05）. CONCLUSION： IFNγ cannot directly promote the differentiation of cholinergic neurons, but plays a role through activating glial cells （except astrocytes） to produce IFNγ like molecules.

Isolation Technology of Single Spore and Optimization of Conidia Culture Condition for Ustilaginoidea virens

The single spores were isolated from chlamydospores of Ustilaginoidea virens with three different maturities by PSA. The isolated single spores were cul- tured on different media at different temperatures under natural light for inducing conidia to explore the optimum isolation technique of single spore and optimum cul- ture condition of conidia. The results showed that the successful isolating rate of single spore from yellow rice false smut balls reached 90.00%. The sporulatina quantities of isolated single spores cultured on PSD and PDB media at 22 -29 ~C （variable temperature under natural light） or 28 ℃ （constant temperature under dark condition） for 12 d were up to 6.3× 107 and 1.1× 106 spore/mL, respectively. PSA was the most effective method to isolate single spores from yellow rice false smut balls of U. virens. The optimum conidia culture condition included PSD or PDB medium, 22 -29℃ or 28℃, natural light and vibration culture. Key words Ustilaginoidea virens; Single spore isolation; Conidia; Culture condition

NEUROBIOLOGICAL EFFECTS OF NRCF DERIVED FROM DISTAL STUMPS OF MOTOR NERVE AND SENSORY NERVE AND b-FGF ON CULTURED MOTONEURON IN VITRO

Objective: To explore the mechanism of neurotropism in peripheral nerve regeneration by assessing the bioactivity of regeneration microcircumstance on motoneurons. Methods The motor branch Of femoral nerve to quadriceps was incised and the distal stump was sutured with one-end silicone chamber. The nerve regeneration chamber fluids from distal motor nerve stumps (motor branch of femoral nerve ) (MD-NRCF) was collected 7d post-operatively, and with the same method, nerve regeneration conditioned fluids from distal stumps nerve stumps (saphenous nerve ) (SD-NRCF) was collected. The dissociated rat’s motoneurons were co-cultured with MD-NRCF, SD-NRCF, basic fibroblast growth factor (b-FGF) and serum-free medium for 72h respectively and then were photographed under phase-contrast microscope. The longest neurites and cellbody areas of motoneurons from each group were measured by cell image processing computer system. MTT colorimetric assay was also used to measure cell activation. Results The cells of MD-NRCF group had significantly longer neurites than the other 3 groups, and their activation was also superior to those of the other groups. Conclusion These results indicate that MD-NRCF has more significant neurite-promoting and neurobiological effects on motoneuron than SD-NRCF and b-FGF.

Studies on culture condition and extracellular hydrolase of psychrophilic bacteria from Arctic sea ice

Arctic sea ice in the polar region provides a cold habitat for microbial community. Arctic sea ice microorganisms are revealed to be of considerable importance in basic research and potential in biotechnological application. This paper investigated the culture condition and extraceIlular hydrolase of 14 strains of different Arctic sea ice bacteria. The results showed that optimal growth temperature of strains is 15 ℃ or 20 ℃. The optimal pH is about 8.0. They hardly grow at acid condition. 3 % NaCl is necessary for better growth. These strains have different abilities in producing amylase, protease, eellulase and lipase. Pseudoalteronomas sp. Bsi429 and Pseudoalteronomas sp. Bsi539 produced both cellulose, protease and lipase. These results provide a basis for further developing and exploiting the cold adapted marine enzyme resources.

Analysis of Ecotourism, Culture and Local Community Empower­ment: Case Study of Wasur National Park - Indonesia

The focus of this research lies in community empowerment based on culture and local communities as well as sustainable ecotourism,which is directed at a complicated mechanism of empowerment elements,local culture that is thick in ecotourism to get added value for the novelty of ecotourism research.The object of research is Wasur National Park(WNP),Papua,Indonesia.Qualitative methods have been used to obtain accurate data and information,i.e.,in-depth interviews with indigenous people to find out the benefits or functions of their culture that can be developed in ecotourism,interviews with leaders and staff of WNP and the Department of Culture and Tourism to find out the potential and processes empowerment and existing tourism potential.As a result,from the perspective of empowerment,local people will easily follow the empowerment process provided that they use methods that are culturally appropriate which is from the viewpoints from the culture of sasi,totem and sacred places.The culture adopted by the community is in accordance with the principles of ecotourism that supports sustainability,environmental conservation,protection of environmental resources and increases economic value.However,it is recommended to carry out modified socialization in accordance with the current conditions.Hence,tourists who visit WNP do not become afraid of the very rigid sanctions which are applied to them who violate the existing cultural and environmental customs.Moreover,to get added economic value in the tourism business within WNP,it is necessary to explore the potential of cultural wealth,natural and biological wealth so that it becomes the main attraction in carrying out the economic empowerment of local communities in the field of ecotourism.

Magnesium degradation under physiological conditions - Best practice

This review focusses on the application of physiological conditions for the mechanistic understanding of magnesium degradation.Despite the undisputed relevance of simplified laboratory setups for alloy screening purposes,realistic and predictive in vitro setups are needed.Due to the complexity of these systems,the review gives an overview about technical measures,defines some caveats and can be used as a guideline for the establishment of harmonized laboratory approaches.